I 7 r2shy
ASSESSMENT OF GROUNDWATER CONTAMINATION
FROM A MUNICIPAL LANDFILL AND
EVALUATION OF REMEDIAL MEASURES
BY
MARK BRICKELL
A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE
REQUIREMENTS FOR THE DEGREE OF
MASTER OF SCIENCE
IN
CIVIL AND ENVIRONMENTAL ENGINEERING
UNIVERSITY OF RHODE ISLAND
1982
TM
Thesis Abstract
The South Kingstown Lanafill is located adjacent to Rose Hi l l
Road approximately one mile north of Peace Dale Rhoae Island
Refuse has been deposited above at and below the water table in an
abandoned gravel auarry since 1967 No grouna-water protection
measures were taken to minimize pollution of the surrounding highly
permeable aauifer material Contamination in some neighboring wells
and in streams to the southwest and east of the landfill has
occurred This study analyzes the present situation by
investigating the areas geohydrologic characteristics grouna-water
flow patterns and contaminated zones Use of seismic refraction
surveys boring logs the USGS ground-water map ana monitoring wells
helped define aauifer geometry ana flow patterns Specific
conductance was measured in monitoring wells ana streams as an
indicator of contamination Electrical resistivity was used in a
known contamination zone The USGS Iterative Digital Moael for
Aquifer Evaluation is used to simulate conditions in the study
area evaluate possible remedial control solutions and make
recommendations
IV
Preface
This thesis is written according to the Standard plan The
Table of Contents lists sections included in the Main Body of
the thesis The Appendices include relevant material that is
referred to in the thesis Main Bodyand a Bibliography
Table of Contents
Page
Title Page
Approval Sheet
Acknowledgement ii
Thesis Abstract iii
Preface iv
Tab I e of Contents v
List of Tables vi
List of Figures vii
Main Body
Introduction 1
Background 2
Description of Study Area 10
Field Studies and Procedures 15
Model Development 30
Model Calibration 41
Computer Simulations 42
Analysis ana Discussion 55
Remedial Measures and Recommendations 75
Conclusions and Recommendations 83
Appendices
Appendix A Precipitation Records 86
98
Appendix C
106
Appendix E
120
Appendix B Boring Logs
Appendix D Computer Program Flow Chart
Appendix F Bioliography
CaliDration of Specific Conductance Meters in4
Computer Data Sheets Ill
VI
List of Tables
Table
1 Well point Water Elevations 17
2 Seismic Refraction Survey Results 20
3 S tream Fl ows 22
4 Specific Conductances in Well points 26
5 Specific Conductances in Streams and Observation Holes 27
6 Schlumberger Vertical Electrical Sounding Results 27
7 Specific Conductance Meter Calibration Table 105
Vl l
List of Figures
Figure
1 Location Map 2
2 Study Area 3
3 SupplyWel l Locations 4
4 Field Grouna-Water Table Contour Map 5
5 Ground-water Map 12
6 Geology Background Map 13
7 Fluctuation in Water Level in W e l l s 16
8 Seismic Survey Location 19
9 We i r Locations and Water Level Ranges 21
10 Surface Contamination Monitoring Locations 24
11 Fluctuation in Specific Conductance in W e l l s 25
12 Electrical Resist iv i ty Sounding Location 28
1 3 Model Grid 31
14 Simulated Ground Water Table Contour Map 32
1 5 Northern Drainage Area 34
16 Landfill West-East Cross-section between Wells W and EC 39
17 Landfill North-South Cross-section between Wells NW and SC40
18 Natural Conditions 43
19 Excavation without Landfill 45
20 Landfill without Excavation 46
21 Landfill Head Contour Cross-section 47
22 Landfill and Excavation with Dam 49
23 Summer Condition 52
24 Landfill ana Excavation without Dam 54
VI 1
25 Infiltrometer Location and Drainage Feature 57
26 Results of Infiltrometer Tests 59
27 Schlumberger Sounding R-l 71
28 Schlumberger Sounding R-2 72
29 No Recharge over Lanafill 77
30 SI urry Wall 80
31 Slurry Wall without Recnarge Over It or Landfill 81
32 Precipitation Record 87
33 Computer Program Flow Chart 107
Introduction
Ground-water contamination of aauifers from municipal landfills
is a widespread problem Contamination of domestic supply wells and
neighboring streams has occured at the South Kingstown municipal
landfill which is located adjacent to Rose H i l l Road approximately
one mile nortn of Peace Dale Rhode Island (Fig 12) The polluted
neighboring wells have been relocated to their present locations to
remove them from tne leacnate plume (Fig 3) Fig 4 inaicates flow
patterns from the landfill which has contaminated streams to the
east and southwest of it The generation of leachate continues as
precipitation recharge and upgradient ground-water sources
infiltrate the refuse To effectively prevent or minimize
contamination from this landfill several remedial options are
available These w i l l be evaluated relative to the areas geologic
setting and hydraulic properties ground-water flow patterns
recharge characteristics and proximity to supply sources
The rate of ground-water flow out of the landfill into the
adjacent aauifer and flow patterns largely depend on tne hydraulic
gradient of the water table and the hydraulic conductivity of the
landfill and aduifer material The hydraulic gradients were
determined by monitoring water-table fluctuations in several wells
located around the landfill and elevation siting in stream
locations and elevations This information enabled a ground-water
map of the area to be developed from where flow patterns can be
developed assuming flow lines are orthogonal to contour lines The
ground-water map in combination with Knowing aquifer and landfill
N
^ooo
feet
Fig 1 Location Map
3
peoy ||H asoa
X ltbull
Alt
f c c
o
^ ^ o o f a
O OJ 83X1
o O
x o
seepage observation -t West
hole Landfill Area
Legend mdash landfill limit bull j--excavation limit r^-s stream copy WNWNEECSeuroSCSEN
monitoring well locations = = = unimproved road
A contaminated domesti supply well
D uncontaminated domestic supply well
feet
Fig 3 Supply Well Locations
5
a 03
N lo ^ gt
laquo c 2
mdash w
3
X o ^
3 O L
o CO
0 opound E bullo
0
co
c
o0
uj ^
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o $ bullA
E c o
w
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pro
ve I 51 H
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UJ _c e poundbullo Mzbull w gt 0
laquorege cc
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3Ogt c $c o_ X
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o a 2 2 u
hydraulic properties and the subsurface geometry enable estimates of
ground-water outflow to be made Streamflow measurements were used
to verify these outflows Contamination levels using specific
conductance measurements as an indicator were measured in wells
streams and observation holes to help delineate the extent ana
degree of contamination An electrical resistivity sounding was
conducted in a known contamination zone
The primary objective of tnis study is to determine flow
patterns in the vicinity of the landfill ana recommend possible
actions to contain or minimize the impact of the contamination In
oraer to fully evaluate these goals the aforementioned parameters
were input to a computer model to produce simulated flow patterns
under different conditions The simulated present conditions were
matched with field water table and stream flow measurements to
calibrate the model A series of simulations were then run to
evaluate flow conditions before the excavations anaor landfill
existed Remedial measures such as reducing recharge to the
landfill and implementing a slurry wall to blocx off leachate flow
to endangered wells were simulated to evaluate their effectiveness
Based on this analysis recommendations are made as to how to
minimize leachate production ano best alleviate the immediate danger
of the contaminant plume spreading to unpolluted domestic supply
wells
background
The South Kingstown landfill is in a geologic setting that is
very similiar to the nearby West Kingston landfill This is located
about 3 miles west of the South Kingstown landfill and has been
studied to assess leachate effects on groundwater quality using
specific conductance as an indicator of contamination levels
(222ltt) Both sites were located in abandoned gravel Quarries which
were filled in with refuse to create the landfill
In the literature numerous authors have shown that the character
of contaminant plumes from landfills are largely dependent on the
local geology and geohydrology A study on Long Island (27) in
similiar glacial material illustrates that the Quantity of flow is
dependent on the hydraulic conductivity of tne aauifer the
hydraulic gradient and the vertical cross-sectional area of the
aauifer it flows through This is expressed as Darcys Law (41)
Q = KIA
wnere Q = flow quantity
I = hydraulic gradient
K = hydraulic conductivity of the aauifer
A = vertical cross sectional area of the flow area
Specific conductance was used as a contaminant tracer to show that
the plume from the landfill flowed downgradient and vertically
through the full thickness of the aauifer A study in Iowa (32)
indicates that the size ana shape of the contamination outflow from
a l a n d f i l l can be predicted from existing geohydrologic conditions
and that the horizontal shape of the outflow extends downgradient
8
from the source and parallel to ground-water flow lines Other
parameters which control the extent of the contaminant plume are
dilution and dispersion in the aquifer and the adsorption properties
of the aauifer material (31)
The amount of leachate generated depends largely on the amount
of water that infiltrates through the landfill to increase tne water
content of the refuse in the landfill The precipitation recharge
that percolates down through the unsaturated zone to the water table
moves in a vertical direction (35) Surface runoff soil moisture
storage losses and evapotranspiration account for tne precipitation
that is not transmitted tnrough the unsaturated zone of aeration
(3315) Upon reaching the saturated zone the water enters the
ground-water flow system Ground-water mounding has been reported
in landfills due to the decreased hydraulic conductivity of
compacted refuse relative to surrounding aauifer material (20)
Chemical processes within the landfill leachate outflow and
surrounding soil cation exchange capacity relative to water duality
of the surrounding aduifer have been studied in Pennsylvania (1) anu
in Delaware (5) A procedures manual for ground-water monitoring at
solid waste disposal facilities was developed by the US
Environmental Protection Agency (USEPA) (9)
Several reports have been written that investigate site
selection design criteria and remedial measures to correct
leachate problems (29) A survey of ground-water protection methods
for landfills in Illinois studies relationships to the water table
theory of liner installation and monitoring devices (13) Sanitary
Landfi11-Leaching Prevention and Control presents a review of
preventative methods such as means to minimize infiltration
interception of ground-water and other pollution control measures
(2 37) A study in Pennsylvania on actual measures implemented to
collect and treat a landfills leachate discharge presents a site
specific study (19) Leachate Quality Improvements After Top
Sealing1 shows that by minimizing infiltration at a landfill in
Connecticut the outflow leachate water quality can be improved
dramatically and contamination plume reduced significantly (6) The
most comprehensive reports on remedial approaches to upgrading waste
disposal sites and ground-water protection methods have been
compiled under USEPA contract (1542)
To assist in evaluating remedial measures the US Geological
Survey (USGS) computer model Iterative Digital Model for Aduifer
Evaluation was used It was originally developed as a model for
simulating two-dimensional aauifer problems (33) It had been
updated since its original development to accomodate different
options (43) This model has been applied to glacial outwash
regions in Rhode Island (717)
10
Description of Study Area
A map of tne landfill area (Fig Z) was obtained from tne town
of South Kingstown The excavation to the west of Rose Hill Roaa
the landfill area directly to the east and the presently operating
area to the east of the central stream comprise tne overall study
area This study will concentrate on the west landfill area whicn
has recently reached capacity and been closed to further dumping
This site received mixed refuse for the past 15 years The depth of
the excavation where the landfill presently exists was approximately
to bedrock in some places Tne exact depths of landfill material is
unknown
The landfill cover has been graded and sloped generally eastward
to convey surface runoff to the eastern side A sandy soil that was
excavated locally was used as tne cover material The northern
section has a vegetation cover and the recently filled southern
section has been seeded and mulched The six monitoring wells W
NW NE EC SE SC were placed by the town of South Kingstown to
provide water quality information
Referring to Fig 2 the west excavation stream drains the area
created by the excavation to the west of Rose Hill Road and flows
throughout the year The central stream drains a small watershed
area which lies to the northwest of the landfill and drys up during
part of the year These streams flow into the Saugatucket River
which flows throughout the year and is larger than the west and
central streams combined
11
The USGS Groundwater Map (18) was initially consulted to proviae
information on the ground-water flow patterns (Fig 5) and the
geology of tne area (Fig 6) The surficial geology borings and the
vertical geologic cross-section at the base of the study area
indicate shallow water table and bedrocic and a nearly constant
saturated thickness (18) Boring logs at the W well ana a point
approximately 150 feet south of it indicate glacial outwasn material
which is primarily sana with a trace of gravel over bedrock at a
depth of approximately 33 feet Borings at the east landfill area N
and S monitoring wells indicate the same aquifer material
(Appendix B)
The ground-water map developed by Hahn is taken as
representative of conditions existing prior to the excavation of the
I l andfill (18) This indicates water-table contour lines that run in i
a general northeasterly direction This means tnat flow was
originally in a southeasterly direction However contamination of
domestic supply wells on the west side of Rose Hill Road has
occurred (Fig 3) strongly suggesting that the original flow pattern
has been altered by the excavation to the west of Rose Hill Road and
the landfill to the east of it Domestic supply wells were formerly
located directly to the west of Rose Hill Road but were aoandoned
when they became contaminated from landfill leachate New wells
were located to the south and west away from the contaminant plume
of tne landfill In addition a well located at the northeastern
corner of the landfill was contaminated and a replacement located to
the east of Us former location on tne opposite side of the central
12
Legend scale 124000
mdash-40 mdashground-water contour elevation
Fig 5 Ground-Water Map
13
Legend feet
TILL
Fig 6 Geology Background Map
14
stream This second wel 1 also became contaminated Domestic supply
wells located near tne northwestern corner of tne landfill and
approximately 300 feet south of it nave remained uncontaminated
These well locations serve as an indication of tne extent of the
landfill contamination which is largely dependent on the groundwater
flow patterns To furtner investigate this problem and provide
substantial information on which to base the geohydrologic analysis
field studies of the area were conducted
15
Field Studies ana Procedures
A map of the lanafill and an aerial pnotograph of the area were
obtained A tracing of these maps superimposed upon another
delineates stream landfill and monitor well locations (Fig 2)
The field investigation concentrated on the west landfill area ana
its aajoining streams ana monitor wells The east landfill area and
the three monitor wells in that area are induced in the latter
phase of the study in oraer to expand the model area
A traverse which establishea tne monitor well elevations was run
using a Carl Zeiss level These were originally sitea in by the
town of South Kingstown using a local USGS reference datum number 40
(18) The wells of known elevations then served as benchmarks for
referencing adjacent stream elevations This in combination with
the depth to water table measurements at each well enables tne
water-table surface geometry of the area to oe visualized
Water-table measurements of the west landfills wells were recordea
over a ten month period to record fluctuations (Fig 7 Table 1)
The east landfill areas wells were monitored for a five month
period Using a given water-table condition a ground-water map was
developea of the area (Fig 4) This indicates an outflow from
the landfill primarily in a southeasterly direction and partially
in a southwesterly direction
Additional bedrock and water-table information was ootainea by a
seismic refraction survey at several locations along the landfill
perimeter A Bison Model lb70C Signal Enhancement Seismograpn was
used to maxe the surveys Lines were run (to a length of kOO feet)
16
17
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2 s s 3 a bdquo s s $ Al s
(1) = $ s 3
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4
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a s
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3 nt
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18
in both directions to provide a check and permit accurate estimates
of the depth to bedrockThe seismic results allow approximate
interpretations of the depth to the water table and bedrocK thus
permitting an estimation of the saturated thickness Ground
elevations at the location of the seismic surveys were determined
from a topographical map and field siting From this information
water table ana bedrock elevations estimates were made Bedrock
contours are listed in Fig 8 In addition a table which
summarizes the seismic refraction results for the unsaturated
saturated and bedrock layers velocities and depths at each survey
location is presented in Table 2
Scream gauging stations were established on the two streams
bordering the west landfill (Fig 9) Three stations were placed on
the central stream These provide information on the influent or
effluent condition of ground-water flow in the upper sections of the
stream and ground-water baseflow from an area adjacent to the
landfill into the stream (Table 3)
The stream gauging stations used were 90deg V-notch weirs The
weirs located in the SE and SW positions were placed in the
streamoea with a liner of plastic upstream to minimize underflow
The weirs located in the NW and E positions were cut to fit in
recesses of concrete culvert pipes Concrete plywooa interfaces
were coated with roofing cement to minimize bypass flow Upstream
water pressure and a snug fit hold the plywood sections in place
All weirs were implaceo according to AigtTM reouirements and flowrates
calculated using the standard 90deg V-notch formula (3)
19
N
seepage West observat ion Landfill hole
Area
Legend landfill limit excavat ion limit
copyWNWNEECSESC monitoring well locations
= = = unimproved road -- WNES-number
seismic refraction locations
-40shy approximate bedrock contpur elevation
feet
Fig8 Seismte Survey Location
20
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21
N
545-594
seepage observation
hole West Landfill
0NE I47-509
Area
Weir 45
i487-531
0 EC Al3-467
Legend bullmdash landfill limit -bull---excavation limit r-s stream
copy WNWNEECSESCSEN monitoring well locations
= = = unimproved road
Weir location and elevation
feet
Fig 9 Weir Locations and Wate r Level Ranges
22
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bull ry m
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NO
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23
A field study to determine the infiltration capacity of a
section of tne landfill topcover was conaucted A modified version
of a double ring infiltrometer was used to study infiltration rates
(4) The cylinder diameters useo in this study were 8 inches and 18
inches A constant head of 6 in was maintained in the
infiltrometer and rates of infiltration were determined Tnese
results and an analysis of surface infiltration into the landfill
are included in tne analysis and discussion section
Specific conductance levels in the monitoring wells in the
streams bordering the landfill and at observation holes near the
landfill were measured (Fig 10) This is a good indication of the
mineralization of water (39) Specific conductances were measured
intermittently over the ten month period to develop a picture of the
extent and degree of contamination in the wells (Fig 11 Taole4j
and in the surface contamination monitoring locations (Fig 11
Table 5) A comparative standardization of the Beckman (short and
long probes) and YSI specific conductances is in Appendix C
A surface electrical sounding using the Schlumberger array was
conducted adjacent to Rose Hill Road at the R-l location (Fig 12)
in an attempt to delineate the vertical extent of the contamination
zone Well W was used as a centerpoint and a reference for
water-table depth pore water conductivity and depth to bedrock A
Schlumberger array electrical resistivity sounding was also
conducted in an uncontaminated area at tne R-2 location (Fig 12) to
provide a comparison background interpretation A seismic
refraction survey N-4 was conducted at the same location (Fig 8J to
24
N
excavat ion
Seepage West observat ion Landfill hole
Area
Stream 1 Seasonal observation 0 EC
hole
East Stream2
Legend sw Weir landfill limit j--1--^ excavation limit
copyWNWNEECSESC monitoring well locations
== unimproved road
feet
Fig 10 Surface Contamination Monitoring Locations
25
8000T
7000
O bull U) W6000
Legend
0 sc A NE O W
A SE O N W
a EC
1 O N D J F M M
Time months Flg11 Flucuatlon In Specific Conductance in Wells
26
Table 4 Specific Conductances in Wells (pmhoscm at 25degC)
West East Landfill Landfill
Date NW NE EG SE W SC N E S
81581 851 938 236 2356
102981 171 3268
11381 3268
111081 304 988 1100 258 3800
111481 426 2736 1216 186 4560
111781 304 3610 433 389 4560
121981 380 1406 129 103 380
1982 160 152
31582 274 760 1064 61 334 8000+ 182 53 84
52182 450 1500 1125 112 712 8000+ 175 255 150
52282 425 1320 1200 110 850 180 320 170
27
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vgtO ^D O ^^ ^O CO ^^ ^^ JJ 2 4) rH rHCO t
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CO -^ C c CO ltuo famp O trade t iH
0
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4)bull
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U ^ raquo ^ - ~ raquo O ^ ^ O t ~ C O r H - r r ^ - ^ ^ JJ r H C M v O r H r H r H r H r H C M C M r H i n c r gt rH CO CM gt laquolaquo - - -^ bullmdash mdash bullraquoraquobullgt -v -v ^^
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in rH cmdash
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28
excavation
West Landfill
Area
Legend bullmdash landfill limit -bullbull--bullexcavation limit r~~s stream
copy WNWNEECSESCSEN monitoring well locations
= == unimproved road
electrical resistivity sounding
feet Fig12 Electrical Resistivity Sounding Location
L
29
allow estimates of depth to water table and bedrocic to be made
Soundings were carried out to 500 foot electrode spacings to insure
that hredrock was penetrated and to facilitate interpretation These
results and a discussion of the soundings interpretation are
included in the analysis and discussion section Schlumoerger
resistivity soundings were made using a Soiltest R-bO unit
30
Model Development
The USGS Iterative Digital Model for Aauifer Evaluation was
usea to develop steady state flow models of the study area (43) A
flow chart of the computer model and a brief explanation of the
subroutines usea is presented in Appendix D The stream locations
elevations and aauiferlandfil1 geometry and hydraulic properties
were input to the model to compute head values at each 200 foot
grid spacing node (Fig 13) The input data which is for the
existing excavation and landfill conditon is listed in Appendix E
The head values that are computed at each grid space are in turn
loaded into the CalComp plotting routine (44) where a grid spacing
is setup with the computed head values at each node The contouring
program linearly interpolates between these head values and
generates a contour map The computer simulated ground-water
contour map for the excavation and landfill is presented in Fig
14
The streams in the model generally serve as controlling boundary
conditions When using computer simulated geohydrologic models of
an area choosing the boundary conditions for the model that are the
same as prevailing conditions in the field is a critical step in
model development Extending the models boundaries to areas in the
field that have a minimum influx of ground-water across them
simplifies the proolem of calculating fluxes from outside the model
area The eastern boundary is bordered by glacial till which has a
low hydraulic conductivity estimated to be 67 ftday(2) This
contrasts to the high hydraulic conductivity of glacial outwash that
makes up the model area of approximately 107 ftday(3036j
31 N
o 9
bullO O
32
33
The Saugatucket River serves as the controlling boundary on the
east A small drainage area directly to the east of it provides a
minimal influx
Beyond the moaels northern boundary the glacial outwash valley
extends to the base of a till covered h i l l on the western half ana
on the eastern side extends along the Saugatucket stream Due to
the relatively large drainage area that lies upgradient from the
northern boundary a recharge flux eduivalent to 10 inyr over the
drainage area on the till hill and outwash area north of the model
area was input as underflow (Fig Ib) Part of this was input at
each northern boundary node Till has a lower infiltration capacity
than outwash so more of the precipitation w i l l be transmitted as
overland runoff resulting in a lower ground-water baseflow The 10
inyr of recharge that results in a ground-water inflow from the
combined till and outwash region represents an estimate that is
smaller than the 14 inyr recharge for glacial outwash areas in
Rhode Island (25)
The glacial outwash valley extends beyond the western boundary
No significant ground-water recharge flux was estimated at this
boundary A relatively low ground-water gradient exists to the west
of this which does not provide a significant flux across this
boundary Tne southern boundary is basically the outflow region for
the area and therefore would not reauire any ground-water flux into
the moael area across this boundary This boundary was set south of
the point that the streams in the model merge together Therefore
the streams which lie to the north of it are the controlling
34
scale 124000
Fig 15 Northern Drainage Area
35
boundary conditions The flux out of the downgradient outflow
region approximately eauals the influx from precipitation recharge
and boundary influxes
When tne stream configuration in the moael area are reviewed it
can be seen that they comprise a large portion of the boundary
area The screams can act as sources or sinks for water in the
model thus providing to and removing water from the aquifer The
leakance option was used in the model which provides for a confining
bed and aouifer area beneath the stream to be input
The leakance is defined as the hydraulic conductance of the
streambed divided by the streambed thickness which in this case is
taken as 1 foot The leakance value at each streambed node
restricts the flow between the aduifer and the stream The
streambed hydraulic conductivity is typically 01 the value of tne
hydraulic conductivity of the aduifer (717) The value 107
ftday was used for a streambed conductivity based on a value of
107 ftday for the aquifer The aduifer and stream hydraulic
inputoutput exchange at eacn node is calculated by initially
finding the difference between the initial field stream head
elevations and the computed head elevation values at the
corresponding nodes This head value is then multiplied by the
(Leakance value at each node) x (stream area of each node)
Therefore if the aduifer head was lower than the stream head the
stream would act as a source of water for the aquifer and vice
versa
36
Tne leaxance input at each stream node is the ratio of the
actual field streambed area in each node to the area of each node
which is 200 ft x 200 ft = 4 x 104 ft2 The west
excavations stream width is approximately 3 ft central 4 ft and
east 5 ft Therefore if tne west stream traverses the node
directly without meandering it presents a leakance of 3 ft x 200
ft4 x 104 ft = 015 Leakance and streamhead values were
input at each node to set up the stream flow parameters in the
models
A recharge value of 14 inyr over the entire area was input at
each node This represents a value of precipitation that is
transmuted into tne ground-water rather than being directly
evaporated evapotranspired through plants or overland flow
runoff The precipitation recharge flow from the stream into the
aauifer and boundary fluxes provide the model witn input flow
parameters
From analyzing the available information it was determined that
the study area lies within a glacial outwash area with a relatively
shallow bedrock The seismic survey around the landfill generally
indicates a depth to bedrock below the land surface of approximately
29-43 ft with corresponding saturated thicknesses of 19-33 ft as
seen in Table 2 This agrees with borings from tne USGS groundwater
map in the stuuy area (18j The seismic survey was run at a low
water table condition which was several feet below the high water
table level (Fig 9)
37
High water-table saturated thicknesses were used to develop
model parameters For the purpose of this model study the saturated
thickness was set at 30 ft except in the vicinity of well W where
there is a bedrock high (Fig 8) At this location a high water
table saturateo tnicxness of 8 ft was estimated In tne vicinity
the seismic survey was conducted the bedrock elevation at this
location is the highest and the saturated thickness the least Tnis
can be seen by an east-west cross section of tne landfill (Fig 16
The boring log for well W indicates a sand trace gravel outwash
material (Appendix B) Boring logs at the eastern landfill area N
and E indicate similar material On this basis the hydraulic
conductivity was estimated at 107 ftday (3036) Witn the
exception of the landfill and the bedrock hign areas the
transmissivity values were set at 107 ftday x 30 ft = 3210
fto day From the literature the hydraulic conductivity of the
landfill material was estimated at I ftday (19) The
transmissivity of the landfill material in tne nortnern section was
estimatea at 1 ftday x 30 ft = 30 ft^day or approximately two
orders of magnitude lower than the outwash In tne landfills
southern section the original excavation was not as deep as in the
northern parts The landfill material was estimated to makeup only
one half tne saturated depth the remainder being the original
glacial outwash material (Fig 17) Therefore the transmissivity
at the southern end was estimated at 15 ft x 107 ftday + lb ft x
1 ftday = 1620 ft^day These values were graded into the 30
ft^day values at the landfills northern halfway point These
38
were input as transmissivity values to the model at their respective
locations This model did not use the water taole option so
water-table fluctuations did not affect the transmissivities
39
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40
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Model Calibration
A simulation was run using the initial estimates of stream
parameters aquifer and landfill hydraulic conductivities
transmissivities boundary and recharge conditions to approximate
water taole conditions in tne fiela Initially the existing
condition of the excavation area to tne west of Rose Hill Road and
the landfill to tne east were modeled in order to calibrate the
model to current field conditions as shown on Fig 4 The simulated
well values (Fig 14) fall within tne range of field values (Fig
9) The resulting contours also provide an approximate matcn This
can be seen by comparing Fig 4 with Fig 14 An additional check
was to match the flow loss and gain in the streams between tne weirs
in the central stream which w i l l be discussed later The
simulated flow value from the excavation drainage stream is the same
as that measured at the SW weir location Having calibrated the
model by approximately matching well water levels nead contours
and scream flow values different field conditions and possible
remedial measures can be simulated
When the model grid was laid out over the study area as viewed on
Fig 13 the stream configuration rarely traversed the grid nodes near
their central axis When the stream locations were input to the
computer the information was documented as crossing the central axis
of the grid nodes The result of this is a slight aberration when
the actual stream configuration is laid over the computer graphics
head contour output The streams dont always cross the groundshy
water contour at the logical location Rather than modifying the
actual stream configuration to adjust then to the computer output
their actual locations are presented
42
Simulations
i The primary focus of the computer modeling is to analyze flow
patterns under changing conaitions in the near vicinity of tne raquo
landfill The study areas overall flow patterns as they exist
today are first presented in order to realize the lateral east-west
head contour lines between the stream that directly borders the
landfill on the east side and the SaugatucKet stream (Fig 14)
This indicates a general southerly flow direction in that area As
different conditions are modeled these contours generally maintain
their east-west orientation In order to facilitate interpretation
of flow patterns in the near vicinity of the landfill flow patterns
to the west of the stream that borders the east side of the landfill
r are presented in the subseauent models
L- Natural Conditions
The results of modeling the original natural conditions are
shown in Fig 18 The excavation and stream to tne west of Rose
Hill Road and tne landfill did not exist in this simulation The
southwestern boundary consists of a drainage stream that was
delineated using an aerial photograph and stream elevations were set
using the topographical map The USGS ground-water map (18) was
used to estimate head values between the west excavation and north
streams These were input to the model as constant heads on the
models western boundary The resulting simulation generally matches
the southeasterly flow direction that is indicated on the
ground-water map (Fig 5)
A3
Legend
x-^- stream 400 = = = unimproved road
I f ee t
Fig 18 Natural Conditions
44
Excavation Without Landfill
The condition of the excavation to the west of Rose Hill Road
with its resultant drainage stream without the landfill was modeled
next (Fig 19) The extent of the excavation ana the location of
the new drainage stream were delineated using the aerial
photograph The west stream elevations were sited in the field and
used in the model The concept of a confining streamoed layer was
excluded in tne excavation drainage stream under the concept tnat no
significant organic layer had been built up within the 25 year
period that the excavation had been initiated Head values between
the west and north stream boundaries were interpolated and input as
constant head values on the northwestern boundary The west
excavation drainage stream creates a condition that alters the
natural ground-water flow patterns by creating a more southerly flow
condition the drainage stream providing a more immediate surface
outflow in that area
Landfill Without Excavation
The hypothetical case of a landfill without the excavation was
modeled next (Fig 20) The low hydraulic conductivity zone of the
landfill changes the natural flow conditions and creates noticeable
mounding This is evidenced by the decreased spacing of the head
contour lines and deviation from the lateral contour lines of the
natural conditions and higher head values (Fig 21)
45
Legend
excava t i on s t ream
400 unimproved road
f e e t
Fig19 Excavat ion without Landfill
46
Legend
landfill limit
bull - s t ream 400 copy WNWNEECSESC
monitoring well locations f ee t bullbull-bull=bull unimproved road
Fig 20 Landfill without Excavation
1
oin CM
bull
m u
0)rf
oO
bullo 9
bullo 9
o rf o o CO 1
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c o
47
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bulla caj
CM
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48
Landfill ana Excavation
The condition of tne existing landfill and the excavation with
the dam is the next condition modeled (Fig 22) The ground-water
elevations used to calibrate tne model correspond to an actual high
water table condition Between the NVJ and pound weir a streamflow loss
of approximately 102 gpm occurs aoout 60 percent of this flow is
lost at the dam site which maintains a head of b-6 feet over an area
of approximately 1800 feet^ This approximates a field value of
1144 gpm influent to the aduifer between the NW and E weir on ]2
December 1981 (Table 3) From the E weir to the SE weir a net
increase in flow occurred of 74 gpm which corresponds to field
increase of b62 gpm
The surface runoff from tne landfill flows primarily toward tne
eastern side of the landfill Increases in water-table elevations
on the eastern side after heavy rains such as the 11 November 1981
storm indicates that this runoff increases outflow gradients to the
stream and therefore increases streamflow Surface runoff input is
not modeled which explains in part why field stream inflow values
are slightly higher than model predictions especially for periods
after a storm has occurred The flow from the SW weir located at
the southern end of the excavation represents drainage outflows from
that area The net flow calculated in the model was 140 gpm
which approximates field conditions of 1642 gpm on
December 9 1981
49
d f l f reg N E
shy
Legend
landfill limit -bullgt-bullgt- excavation ^-N_X- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road
-40mdash approximate groundwater contour
400
feet
Fig 22 Landfill and Excavation with Dam
50
The modeled flow patterns suggest how the various contamination
zones around the landfill have developed to their present state
They indicate a flow to both the southeast and southwest on their
respective sides of the groundwater divide Evidence of a
southwesterly contaminant flow is presented when the continued high
specific conductance contaminant level in tne observation seepage
hole is realized (Table 5 ) In addition the specific conductance
increase in the west excavation stream is evidence of an influent
contamination flow
Contamination flow to the eastern and southeastern side of the
landfill is obvious High specific conductance levels in the wells
on the eastern side (Table 4 ) a specific conductance increase
between the E and SE weirs (Table 5 ) and contamination in the NE
domestic supply well (Fig 3) present conclusive evidence of
contamination to the eastern side of the landfill
An anamalous condition that exists is a domestic supply well
located approximately 300 feet due south of the landfill remains
uncontaminated (Fig 3) Flow patterns indicate that contamination
would be transported from the landfill south to this area
(Fig 14) One explanation is that a pocket of clay at the southern
end of the landfill area was discovered in the original excavation
for the landfill (lt6) This evidently prevents leachate from
reaching this wells radius of influence
51
Summer Conaitlon
As described earlier during dry months of the year the stream
that normally borders the northern and eastern side of the lanafill
may dry up as far as a point southeast of the E well Tnis
condition existed from the 15 August 1981 to the 27 October 1981
period when streamflow commenced in the northern part of the stream
yet did not overflow the north dam until 17 November 1981 This
created the present day continuous flow condition throughout the
stream These summer conditions were modeled by removing the stream
above the aforementioned location while other conditions remained
the same (Fig 23) Summer condition well water levels listed in the
model generally match field low water table conditions (Fig 9)
Because there is no stream upgradient from the landfill to provide a
stream head and infiltration through the streambed groundwater
runoff from the area north of the lanafill is the controlling flow
input In these moaels an average recharge of 14 inyr was used
which represents a yearly average The summer recnarge conditions
are prooably lower given the effects of decreased rainfall and
increased evapotranspiration during the summer months A domestic
supply well whicn exists northeast of the landfill (Fig 3) nas a
greater potential to be contaminated from the lanafill at tnis time
than when the stream is flowing Flow patterns from the landfill
are such that during an upper stream no-flow condition groundwater
flow patterns are more in an easterly direction than in a
southeasterly direction The stream would act as a source of
infiltrated water upgradient from tne landfill and provide a
52
I ^N gt i I i j i -r- -bull- bullr -T- t- -r- i- TJ JV
bullbullT laquo ^ O - laquo bdquo xi cshy
H r^~ I -~- --^ X- = mdash x^ N
^--^ A bull O^NW -v - gt-bull Ni i I _____mdash - bull laquo l - mdashmdash 1 deg I ^ltv I C
I reg NE A
Js bull vbull A ~ - v T gt- ^ ix - N
-5Z- | N TfS lV I -bull bull iA i gt gt I ^ bullr-Ky L bull 1 _- copy]wgt-- - bull- mdash - - shy
= r Y ~mdash ltmdashA A
^^-lt A _ - - - - bull Hmdash - reg EC x ^-mdash mdash I ---mdash_mdash -t-V-^N - y
I- -bull - r x i X
V ^ 7 I -v (^~~^^r ^^^
sc Emdash-bull vV JI - - - ~ r )N y- -
X - bull r bulllt
^bull^ y y Jlaquo^ - -lt shy
T s^ lt^ ^ +^-b (
X
Legend
landfill limit j-j-bullraquobull excavat ion gt^ -x- s t ream
reg WNWNEECSESC monitoring well locat ions
= == unimproved road fee t
Fig 23 Summer Condition
400
53
constant head across tne northern section of the landfill This
would tend to orient the flow in a more southerly aowngradient
direction In addition the stream which flows adjacent to the
northeastern well could provide a source of infiltrated clean water
to it which would minimize the possible contamination from landfill
leachate
Without Dam
During tne spring scream flow condition the dam failure which
occurred between the 15 March 1982 ana 9 April 1982 monitoring
periods decreased flow to the aauifer and landfill This eliminated
the 5-6 foot head difference over a 19000 ft^ area which had
created a larger area and elevation head for infiltration to occur
The condition without the dam was modeled by reducing the area
encompassed by the dam to a 4 foot wide stream channel thus
reducing the leakance value at that node (Fig 24) The flow change
from the stream to the aduifer between the NW weir and E weir
reduced the model flow loss to 50 gpm Tnis corresponds to the 9
April 1982 monitoring period which indicates a 30 gpm loss
As compared to the previous flow loss in the upper stream
sections to the aauifer the 21 April 1982 and 22 May 1982
measurements between the NW and E weirs indicate a flow gain The
streamflow conditions have changed from an influent
stream-to-aauifer condition to an effluent aduifer-to-stream
condition that increases flow downstream
54
Legend
landfill limit j--i--i- excava t ion x-gtmdash^- stream 400
copy WNWNEECSESC monitoring well locations
= == unimproved road f e e t
Fig 24 Landfill and Excavation without Dam
55
Analysis and Discussion
In order to fully understand flow patterns and Quantify leachate
outflows at the landfill it is necessary to arrive at an estimate
of flow inputs from precipitation ana upgradient sources In the
following analysis it will be demonstrated that the rainfall input
to the landfill is the factor which controls leachate generation A
calculation using the H inyr recharge over the area of the
landfill was made to estimate the leachate outflow due to rainfall
infiltration An estimated 134 gpm is generated from the entire
landfill area Simulation of the existing conditions (Fig 24)
indicates a groundwater divide in the landfill is located
approximately at the western third Therefore approximately 23 of
the generated leachate flows to the eastern side of the landfill or
9 gpm The effect of the flow input from the upgradient stream is
evident when tne summer condition witnout the stream is viewed
(Fig 23) Without the stream to infiltrate the landfill and the
recharge and northern boundary condition as the flow inputs the
head at the northern end of the landfill drops about 5 feet from its
previous value A flow pattern from the north central part of the
landfill to the eastern side indicates a 12 feet head difference
with recharge - but with the upgradient stream a 16 foot head
difference occurs Considering the transmissivity change the
stream would increase the leacnate outflow from the landfill
approximately 43 under a low water table stream influent condition
to the aauifer This would increase leachate outflow to the east
side to approximately 129 gpm This value approximates the
56
outflow at the SE weir location during the summer monitoring period
when the upper stream was not flowing (Table 3) The outflow from
the western third of the landfill whicn lies to the west of the
ground-water divide would be approximately 63 gpm
Realizing the importance of infiltration to tne landfill as a
major influence on the generation of leachate an analysis of this
w i ll be discussed An estimate of infiltration was made using the
precipitation recora for October ana November (Appendix A) During
this time period a minimum of direct evaporation ana
evapotranspiration occured and the grouna is not yet frozen The
top cover over the lanafill is generally 05 ft to 2 ft of local
sandy soil and subsoil availability determined what was used The
top of the landfill is at an elevation of 92 ft as compared to the
ground surface at well W which is at an elevation of 76 ft
(Fig 25) This compares to the well W water level which is at an
elevation of approximately 52 ft This creates a long path for
infiltration through the unsaturated zone The topcover generally
slopes eastwara at a grade of 2-5 The west side maintains a
relatively steep slope of 10-15 ft drop within 50 ft ana the north
and eastern slopes have a more gentle slope of approximately 10 ft
within 100 ft distance An unlined surface arainage swale channels
surface runoff from the northern section of the landfill past the
NE well to the eastern side ana low area in the vicinity of the E
well This has a drainage swale to an area near the stream but
doesnt directly connect to tne stream A poorly graaed drainage
swale exists on the landfills left side The landfill material has
57
excavation
seepage observation ^
hole
Legend bullmdash landfill limit -^--excavation limit r^s- stream
copy WNWNEECSeSCSEN monitoring well locations
--- unimproved road O location of amp Inf i l t rometers O
feet
Fig 25 Infi ltrometer Locat ion and Drainage Feature
58
been placed in 10-12 ft cells and covered with 1 ft of soil at the
end of each day The material has settled differentially creating
areas for depression storage
An estimate of the percentage of precipitation that infiltrates
the landfill was made from precipitation records recorded well
elevations and an estimated specific yield for the landfill
material The volume of water that infiltrated should eaual tne
specific yield multiplied by the well water level rise Several
recharge periods were studied using this relationship Once the
percentage of precipitation that has infiltrated is determined the
percentage that is translated into runoff is simply the remaining
percentage if evaporation is neglected
From the literature for a slightly inclined slope of 2-5
typical runoff coefficients range from 10-20 in either sandy or
heavy soil (16) The landfill cover is generally sloping to the
east which creates a long path (approximately 400 ft) before the
runoff reaches the steeper slope on the eastern side of the landfill
of 15-20 The long drainage distance creates a greater time for
rainfall to infiltrate Another consideration is the actual
capacity of the soil to conauct water into the soil which was tested
in the field using double ring infiltrometers An average initial
percolation of 8 mmhr the first hour and a subseauent rate of b
mmhr occurred (Fig 26) The 8 mmhr rate compares well with
other sandy soil infiltration rates (14) Therefore if the
intensity of the rainfall exceeded a 5 mmhr rate for several hours
59
CO + 09 o
E o
CO
o Z pound C
O
C9
o DC
CO
CD CM
ogt CO N- to -4 CO CM
jq tuu i U O | raquo B J J | | J U |
60
on a poorly drained surface the additional rainfall would be
translated into runoff because the soils infiltration capacity had
been exceeded
The initial 8 mmhr infiltration rate was due to the pore spaces
in the sandy soil being filled and the subsequent 5 mmhr rate was
percolation into the low permeability landfill material The tests
were conducted in November assuming a minimal evapotranspiration
and the field capacity of the sandy soil had been maintainea
The W well was used as representative of the water elevation
changes in the landfill because it is directly adjacent to the
landfill 900 ft distant from the upgradient stream This minimizes
the effect of infiltration from the stream and maintains a high
contaminant level During periods of high runoff conditions excess
surface water ponded in a poorly graded drainage swale on the west
side and directly adjacent to the landfill This influenced the W
well at a time the contamination level dropped (Fig 11) Before
this occurence in mid-December the rise of the W well closely
matches that of the SC well and a background well SK6 which is
located outside the study area (Fig 7) Therefore it was analyzed
as a valia indication of the water level rise during the mid-October
to mid-December period The monitoring of the SC well was
intermittent due to inaccessaoility because of 10 ft extensions
being placed on the well as the refuse was being filled in arouna it
61
A high rainfall period from 14 November 1981 to 1 December 1981
was chosen for the initial study period The effects of
evapotranspiration were neglected due to the cool temperatures
experienced at this time Therefore it was assumed that the field
capacity haa been reachea and tnat any additional input to tne
unsaturated zone would result in direct percolation to tne saturated
zone During the time period 14 November 1981 to 22 November 1981
029 ft of rainfall fell and the well W rose from 488 ft to 493
ft - a 05 ft increase During the next 8 day period there was no
precipitation yet the W well continued to rise to 4972 - a 042 ft
increase The slow percolation of water through the landfill
material would account for the latent rise in the well water level
From previous reports a specific yield for refuse was estimated to
be 028 (1920) This value is dependent on the original compaction
of tne material age and resulting consolidation
During the 14 November 1981 to 1 December 1981 period 029 ft
of rain fell and the well increased 092 ft The following
relationship is used to evaluate the infiltration value and runoff
I = (Sy) h
Sy = specific yield
h = well rise
I = volume infiltrated
I = (028) (092 ft) = 0261 ft
62
The difference between the precipitation and the infiltration is
the runoff (assuming no evapotranspiration) Therefore 029 - 026 =
003 and furthermore 003029 - 13 runoff This corresponds in
the literature to a typical runoff coefficient for an inclined
surface of 2-5
Analyzing a longer precipitation period from 18 October 1981 to
1 December 1981 a net precipitation of 043 ft (accounts for
evaporation) occurred less 10 for runoff or 039 ft infiltrated
This results in a 139 ft elevation increase The well water level
actually increased 132 ft shy only a 5 deviation from the
calculated
From tnis investigation it is seen that a large proportion of
the precipitation has the potential to be transmitted into the
landfills saturated zone Exceptions are wnen heavy precipitation
periods exceed the soil percolation capacity frozen ground prevents
infiltration and direct evaporation and evapotranspiration recycles
the ponded surface water and infiltrated soil moisture back to the
atmosphere In retrospect water temperatures within the monitoring
wells could have been measured to indicate thermal effects from the
landfill on ground-water temperature Ground-water temperatures
were assumed to be 50deg F (9)
63
Specific conductance measurements serve as an indication of
contamination levels These measurements are used to trace leachate
movement which represents ground-water flow patterns Factors which
must be considered when monitoring pollutants are the attenuation of
the leachate contaminants which occurs both in the zone of aeration
and the saturated zone The former is a more complete process
Dilution dispersion and cation exchange are the primary factors
involved in decreasing leachate concentration in the saturated
zone The glacial outwash materials of southern Rhode Island do not
have a cation exchange capacity or a high buffering capacity so
attenuation is simply by dilution and dispersion (22)
The NW well consistently exhibits relatively low specific
conductance levels even though it is in landfill material It is
situated in a drainage swale and ground water elevations range from
543 to 5944 This is several feet below the upgradient stream
elevation of 64 feet which is less than 400 feet away The bottom
of the wellpoint is at an elevation of 5312 feet well into the
landfill material Infiltration from the stream to the landfill has
occurred at this location
The W well is situated on a bedrock high adjacent to the
landfill approximately 900 feet from the upgradient stream and its
water level is higher in elevation than the excavated pit (West
Observation Hole) which is 300 feet directly west The W well
maintains a contaminated level A poorly graded drainage swale to
the west of the landfill provides areas for extensive ponding and
infiltration to occur which explains the drop in conductance after
a high runoff period
64
The SC well is located in landfill material and has a
conductance of over 8000 umhos This indicates that leachate is
undiluted The oottom of the wellpoint is at an elevation of 389
feet which is situated in the landfill material
High specific conductance measurements in the west observation
hole and well W and their relative elevations indicate a
west-southwesterly flow direction from the landfill Infiltration
recharge and leakance from the stream into the landfill provides the
necessary elevation to cause outflow in this direction
Contamination from the landfill to the surrounding streams is
evident (Table 4) During the period 15 August 1981 to 27 Octooer
1981 there was no flow in the stream that Borders the northern and
eastern side of the landfill until a point just south of the E well
was reached High specific conductance levels in the EC and NE
wells were recorded (1000 jjmnos) At a point directly east of well
EC a pool of water existed that was relatively uncontaminated which
is designated as the East Stream] location (Fig 10) At a point
just south of that (East Stream^ polluted water in the streambed
was flowing at a low rate This was measured at the SE weir
location and which had a high conductance also Flowrates varied
between 6 and 23 gpm and specific conductances were over 350
pmhos This low water table condition flowrate is the baseflow from
the eastern side of the landfill and indicates a southeasterly flow
direction from it
Streamflow commenced in tne northern part of the stream 21
October 1931 and the north dam oegan to f i l l Stream specific
65
conductances were low indicating a clean water source Tnis
continued until 17 November 1981 when the dam overflowed ana flow
throughout the east stream began A weir was placed at the Rose
Hill Road NW location and was compared to flowrates at the SE
location Flowrates decreased and specific conductances increased
between these two locations
To further investigate the condition of a lower flowrate
downstream than upstream an intermediate weir was placed at the E
weir location (Fig 9) This snowed tnat the stream from the M
weir to the E weir was losing water to the aauifer (influent
condition) and gaining water at the SE weir (effluent condition)
The condition of a net loss of water between the NW and SE weirs
remained until 19 December 1981 when a snowmelt rain condition
caused increased surface runoff and a net increase in flow at the SE
location Upon analyzing the March and April 1982 streamflow
conditions the expected case of a net ground-water pickup from the
E to SE weir continued The explanation for tne initial net loss of
ground-water is the fact that the leakance from the upstream section
was being discharged into aauifer storage to raise the ground-water
table to an eduilibrium level Upon reaching a high recharge
equilibrium steady state condition any additional input will
eventually be transmitted as baseflow out of the landfill and a
downstream net pickup will occur A hign water table condition
prevailed during the January through May period maintaining this
condition In April the north dam broke through reducing the head
in that area by 4-6 feet The 9 April 1982 monitoring revealed that
66
an influent condition remained between the NW and E weirs but at a
reduced rate The 21 April lower stream flow condition shows a
small pickup of water between the NW and E weirs indicating the nigh
water table and low stream flow conaitions combined with the absence
of the dam had changed the conditions to an effluent condition
This was evident in the May monitoring period
Evidence of contamination on both the western and eastern sides
of the landfill supports the existence of a ground-water divide in
the landfill The west stream which drains the excavated area to
the west of Rose Hill Road shows contamination pickup between its
northern section and the SW weir The W well and ooservation hole
indicate high contamination levels which reinforces the concept of a
contaminant outflow to tne west excavation stream
As shown previously flow towara the eastern side of the
landfill is evident from the nign specific conductances and specific
conductances increases in the stream This is especially evident
during low flow conditions when the stream starts at a point to the
east of the landfill and flows with high specific conductance levels
From the literature a relationship between specific conductance
and dissolved solids exists the dissolved solids (mg1) are
approximately equal to the specific conductance times a factor
ranging between 55 and 09 (39) in this case it is taken as
065 (41) The dissolved solids increase coupled with the stream
flow increases provides a basis of calculating the dissolved solids
outflow to tne stream This calculation method was used in a
previous study (26)
67
The relationship
=Cinout Coutflow Qoutflow - Cupstream Qupstream Qinput
where the numerator is the streamflow pickup and the C- and
Q-jnput is the concentration and flow input from the ground-water
This can be used to estimate dilution level outflows from the
landfill Initially this is used for the ambient ground-water
pickup between the E weir and the SE weir This entire flow doesnt
come from tne lanafill but much of it is conaucted in the high
transmissivity area between the lanafill and stream from upstream
leaxage ana surficial recharge Tnis is evident when this section
of the flow pattern is analyzed on Fig 22 Therefore the landfill
outflow is mixed with tne ambient groundwater flow which dilutes the
landfill leachate before it enters the stream To illustrate-this
concept a calculation using the 9 December 1981 monitoring is used
At this time a flow of 672 gpm occurred at the SE weir with a
specific conductance increase of 7 ymhos between the E and SE
weirs The dissolved solids increase would be approximately 795
Today in tne stream
Where
Co = 90 jumho at SE weir
Qo = 672 gpm at SE weir
Cus = 83 jumho at E weir
Qus = 606 gpm at E weir
Qinput = 66 gpm gain
Cinput = 154 jumho
68
The 154 jumho value represents the contaminant level in the
ground-water adjacent to the landfill
This relationship is applied to approximate the concentration
level dilution in the ambient ground-water between the landfill and
stream The aforementioned relationsnip is in turn applied to the
landfill outflow into the ambient ground-water flow adjacent to the
landfill The ground-water receives landfill leachate dilutes it
and then transmits it to the stream The previously calculated
value of 129 gpm was used as the outflow from the landfill
Co 154 jumho flows into stream
Qo = 67 gpm flow into stream
Cus = 83 jumho background level
Qus = 67 gpm - 129 gpm = 541 gpm
Qinput = 129 gpm from landfill
Cinput = 451 jumhos
Approximately tne same contaminant levels from the landfill (tbl
umho) are arrived at as existed in the summer streamflow conditions
when the upgradient ground-water flow adjacent to the landfill was
at a minimum
In addition to using specific conductance to define
contamination zones electrical resistivity can be used to indicate
contaminated areas The measured earth resistivity is inversely
proportional to the conductivity of ground-water Water containing
contaminants with high ionic concentrations are more electrically
conductive and will have lower resistivity values than surrounding
natural ground water Therefore resistivity methods can be used to
69
delineate plumes of contaminated ground-water that have hign
specific conductances This has been demonstrated by several
investigations (11122328374045)
In this study a Schlumberger vertical electrical sounding R-l
was made in an area of known contamination at the W well (Fig 12)
Given the geologic constraints provided by the well boring log a 4
layer computer model was used to match field survey values A
Schlumberger sounding R-2 in an uncontaminated area north of the
landfill in the same geologic setting was used to provide a
comparison background sounding (Fig 12) A seismic survey N-4 was
made to obtain water table depth and depth to bedrock as input
parameters to a four layer resistivity model (Fig 8) Tne results
of the electrical soundings have been tabulated in Table 6 and
plotted in Fig 27 and 28 respectively
The ascending portion of the field Schlumberger curves were
initially matched using a two-layer ascending type master curve to
provide an approximate depth and apparent resistivity of the
overburdened topsoil layer (8) Tne second unsaturated layers
apparent resistivity was determined by using the graphical
interpretation of total transverse resistance The total transverse
resistance is approximately eoual to the peak value of the curve
times the corresponding Ab2 distance it occurred at This in turn
is eaual to the sum of the first two layers apparent resistivity
times their corresponding layer depths
70
bullH
OJ bull bullH 4J CO CM
c ce G bullrH
j-gt ca c c a 3 ltu O L
co CO 0
bullo Q bull laquos c n 3 -U OrH f~ 3 bO ltn y CO O cc CO ^mdashN
QQ bull
bO bOJJ C C Ci_i
O l T i O O O O O O O O O O O O O O O O bullH bullH mdash^ bullo 0 C c3 f| 3 O raquo O CO CQ
CO
rH
CO O
L 4J
^ltU
i- 1 ^n ^b O 4-) bull2 CM bullH C OJ 1 -U bullH CO C L O a ^-^ 0) a
rH c a L CD ltu (1) 3 tlt bO cO I
3 a 0) a Q 4J laquoa e CO 3 (H bO c C O bullH
CO TJ C 3 bull
bull O bO -i-3
0 CO C O3- O G O O O O O O O O O O O O O O O O O O ft rt1 -raquo - t l S^ ft tfigt f I mdash^ K_ l_ raquo mdash I gt fgt I l 1
(1) 0 rH CO CJ JD o^^ CO CO CQH lts
71
Legend
A actual field measurement
-e- interpretat ion
10000 bull
6000 bull 5000
4000-
3000shy
pound2000| ltD
_ r 1000
09
5 600 pound 500 - 400
I 300 a a lt 200
100 10
Fig 27
20 30 4050 100
Distance AB2
Schlumberger Sounding
200
feet
R-1
400 600
72
loooot
6000 5000 4000
3000+
laquo2000 e
r 1000
raquo 600 pound 600 ~ 400
$ 300 a a lt 200
100
Legend
A actual field measurement
-Qmdashinterpretation
10 20 30 40 50 100 200 400 600 Distance AB2 feet
Fig 28 Schlumberger Sounding R-2
73
Formula T = f
Background Sounding (9000)(15) = (3110j (1 7) + gt2(8)
= 16214 n- ft
W Wel l Sounding (b200)(60) = (500) (2) + pound2(28)
= 13250 SL- ft
To determine a resistivityp3 value for the third layer a
graphical interpretation for the longitudinal conductance S was
used(48) This is eaual to the sum of each individual layers depth
divided by their apparent resistivity
Formula S = -r1 +~r-raquobull-ra
Background Sounding 0017 = yyg + ~^
= IbOU - ft
W Well Sounding 0285 raquo -ggg 7^3 J~
= 179 v-ft
These values were input to a program which calculates a
schlumberger sounding curve (47) The theoretical sounding curves
approximately match the field curve as viewed on fig 27 and fig
28 To provide a check on the apparent resistivity of the saturated
layer at the W well the following relationship was applied 1OOOO
= spec-jfic conductance (umhos)
74
At the W well the specific conductance was measured to be 3 00
jmhos at approximately 10degC
Assuming a formation factor of 45 for the glacial outwash (23)
material Archies law is applied to estimate an apparent resistivity
of the third layer (7)
fgt FF x p
A= 45 x 103-n-ft
A= 4G3 JL-ft
This is a reasonable approximation to tne 3i= 179^-ft calculated
analytically from the sounding curve interpretation
75
Remedial Measures
With the analysis of f low patterns and contamination zones
recommendations to minimize the environmental impact of the leachate
can be reviewed The basic technique is to minimize all sources of
water reaching the refuse so that leacnate production is minimized
The oiversion of precipitation by a relatively impermeable cover and
proper channeling of runoff would minimize percolation into landfill
material Caps and seals can be constructed of clays fly ash
soils soil-cement lime stabilized soil memorane liners
bituminous concrete and asphalttar materials (15) Proper
contouring and grading will help minimize infiltration If a soil
cover is used a vegetative cover can be planted which will utilize
some of the infiltrating flow through evapotranspiration losses
during the growing season By minimizing the length of slopes and
providing proper drainage channels tne surface runoff can be
conveyed to a downgradient area outside the recharge zone
Therefore this surface water will not increase leachate production
from the landfill Also by increasing the slope of the cover over
the landfill itself a higher percentage of runoff and lower
infiltration will occur
To minimize upgradient ground-water influx to the landfill an
impermeable subsurface barrier or intercepting trench could be
used Barriers can be made of bentonite slurry-trench cutoff walls
grout curtains or sheet piling cutoff wal ls extending to the bedrocic
or an impervious layer to effectively prevent water passage or
create a head loss that wil l lower the water table In addition an
76
intercepting trench which has a perforated drain at tne lowest part
of the water seepage zone could be used to intercept and divert the
entire flow
These possibilities have been evaluated with the help of the
model to determine workable solutions for this landfill The
primary concern is to eliminate leachate flows to domestic wells
Initially a simulation was run that eliminated recharge over tne
landfill area (Fig 29) This had a considerable effect on the
ground-water flow patterns of the landfill area The mounding that
had previously occurred under normal recharge conditions was
eliminated and a general drop in the water taole within the landfill
of 2-3 ft occurred The effect of eliminating recnarge over the
landfill when the upper stream is running would cause greater
infiltration from the stream as evidenced by only a 2 ft head loss
in the landfills flow conditions This is evident when comparing
Fig 29 with Fig 24 Tnis indicates that this measure would only
marginally reduce the resultant leachate flow from the landfill
material that lies below the water table In another situation
where there is not such a strong potential for upgradient flow this
measure has proven quite effective (6) In this case the landfill
cover consisted of four layers an intermediate sand and gravel
cover immediately above tne regraded waste materials a 4 inch sana
bed designed to protect the overlying membrane a ilO mil flexible
PVC membrane and an 18 inch final cover of sand and gravel
77
Legend
landfill limit -raquo- -^ -raquobull excava t ion x-^x- s t ream
400 copy WNWNEECSESC monitoring well locations
= -= unimproved road fee t
Fig 29 No Recharge over Landfill
78
Controls such as 10-30 mil polyvinyl chloride covers favor the
development of an anaerobic environment which increases waste
decomposition time and would necessitate installation of gas vents
at several locations on the landfill cover Tne integrity of tne
synthetic cap may be further threatened by subsidence which create
differential stresses on liners Settlement would create areas for
ponding and depression storage and eventually necessitate regrading
the landfill surface The landfills south-central area has oeen
filled within the last year and will prooably need to be regraded
due to settlement within the next few years
Another possibility for a liner would be a soil-bentonite
cover A layered cover consisting of natural materials with low
permeabilities such as bentonite clay followed by a layer of highly
permeable material such as sand and finally a layer of topsoil can
be used Due to potential drying out and cracking of the clay liner
a synthetic liner is the preferred method
The most immediate technique is to grade contour and vegetate
the landfill cover which has been done at this site Althougn an
impermeable cover would probaoly reduce the amount of leachate
produced it would not eliminate the upgradient flow and provide
guaranteed protection of wells in the vicinity of the landfills
northwestern section
A slurry trench along the northwestern perimeter of the landfill
would effectively cutoff upgradient infiltration and divert recharge
infiltration in a southeasterly direction thus removing possible
leachate outflows from the radius of influence of the neighooring
79
wells This has been simulated using the computer moael ana flow
patterns as shown in Fig 30 Contour lines are distorted in the
vicinity of the slurry trench due to the 200 ft nodal spacing
Transmissivity values of 1 ftday were input at the slurry
locations to simulate an impermeable barrier Tne surface recharge
at those nodes does not infiltrate the relatively impermeable grid
nodes at the slurry locations and flows to the edge of the noae
thus creating a dramatic head loss within a short spacing To
effectively simulate this a variable grid spacing should be used
with reduced node grid spacing at trench locations to eliminate
distortion The computer simulation shows that the slurry trench
could direct flow in the landfill area in a southeasterly direction
and away from endangered wells In addition it would reduce
upgradient infiltration from the stream into the landfill This
measure would prevent leachate from spreading beyond this carrier to
possibly contaminate neighboring wells
The combination of both the slurry wall and impermeable cover
would be ideal measures to minimize generation of leachate and to
stop its spread to neighboring wells The slurry wall without
recharge over it or the landfill is simulated in Fig 31 This
indicates a lower water table tnan eliminating the recharge to the
landfill The slurry wall has blocked upgradient ground-water flow
at its location to the landfill
80
Legend
landfill limit -laquo- j -laquobull excava t ion ^^- stream
copy WNWNEECSESC monitoring well locations
= = = unimproved road ssi slurry wall
f e e t
Fig 30 Slurry Wall
81
Legend
landfill limit j- j- J- excavat ion x-v^gt- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road s==s slurry wall
400
feet
Fig 31 Slurry Wall without Recharge Over It or Landfill
82
An intercepting drainage trench is considered next If a trench
was excavated to a 30 ft depth in the outwash material extensive
shoring would be required In addition difficulties would arise
when the trench was excavated below the waterline Tne trench would
be sloped to provide drainage and backfilled with a highly pervious
material to intercept and divert leacnate locally a conouit which
is perforated on the top to allow infiltration and unperforated on
its lower perimeter to permit continuous drainage to the collection
treatment center would be installed on the bottom of the graded
trench The difficulties involved in excavating below the water
table ano shoring the sidewalls to permit implacement of a drainage
conduit at a 30 foot depth make this option increasingly infeasible
83
Conclusions and Recommendations
The location of the South Kingstown landfill in permeable sand
and gravel glacial outwash material (107 ftday) combined with the
high hydraulic gradient across the landfill area (20 ft1600 ft)
creates a high potential for ground-water contamination to occur
This is intensified because refuse nas been placed below the water
table The low hydraulic conductivity of the compacted refuse (1
ftday) and the excavated area to the west of Rose Hill Road have
both contributed to modifying the original southeasterly flow
pattern These modifications have created a ground-water divide in
the landfill at approximately the western third section Tnis
results in approximately 13 of the leachate flow from the landfill
or 63 gpm flowing in a southwesterly direction and 23 or 129
gpm flows in a southeasterly direction Infiltration from
precipitation recnarge over the landfill (up to 9Upound) and from tne
upgradient stream during low water-table periods provides tne
necessary influx into the landfill Evidence of contamination is
clearly seen on both the east and west sides of the landfill which
reinforces the previously stated flow patterns
Of the several remedial measures reviewed the contouring and
grading of the landfill topcover and drainage swale provides the
most immediate protection The topcover has been graded mulched
and seeded to provide a low runoff slope generally to the east
The drainage swale on the left side of the landfill has improperly
graded sections which should be corrected Its northern section
could be drained into the northern sections swale and the southern
84
section drained to the southeastern section of the landfill Tne
point of the drainage swale which divides the northern drainage
swale from the southern one should be determined by a field survey
Cost is a major contributing factor when determining which
remedial measure is to be applied to the given situation For the
purpose of this report cost estimates are not presented but rather
the effectiveness and feasibility of the remedial measures are tne
primary considerations As was reviewed and simulated in the
computer models the slurry trench and impermeable cover over the
landfill are two viable options that would effectively provide
protection to the domestic supply wells in tne vicinity The
impermeable cover would eliminate precipitation recharge into tne
landfill yet drop the water table only a few feet due to upgradient
infiltration from the stream This would decrease the hydraulic
gradient thus diminishing the potential for a contaminant outflow to
surrounding wells The supply well of primary concern is one to the
west of Rose Hi l l Road marked well D on Fig 2 If contamination
occurs in this well the most effective measure would be to block
off leachate flow in this direction by installing a bentonite slurry
trench at the location indicated previously This would effectively
prevent leachate flow in the westerly direction and diverts it to a
more southeasterly direction In addition the slurry trench
precludes infiltration flow into the landfill from the upgradient
stream
85
Tnis report has effectively reviewed tne original ana existing
flow conditions and contaminant levels in the vicinity of the Rose
Hill landfill The purpose was to provide an understanding of
ground-water contamination patterns and study possiole remedial
measures
86lt
Appendix A
Precipitation Records
Monthly normal precipitation 1941 -197O
i$l Total monthly precipitation
KINGSTON RI
14
ia
^JO T I bullbullL
pound 111 laquobull
4
a
n
-
^
-
-
KS1JAN
^Ii R3 HB MAR
1
1 APR MAY
1
1 JUN
1981
JUL
-bullraquolaquo H
AUO SEP
K3~~f$s bull
_imdash
i1S 1
OCf NOV OtC
171 1 iI1
JAN HB MAR APR MAY
198
Fig 32 Precipitation Record
- - - -
IM 1 MtvJrflgtlgt c ortli-A t lUN I r nraquo rl - -
gt|MO CLIMATOLOQICAL OUSERV ATIONshyr-r bull JK gt raquo - 1
i5fWA I VAPOR Al IOH -bull AIM If MPCRATUM bullF 0 riccipn AT ION UNO IlMf
bull 14 H 14 H mdash Vshy ADDITIONAL DATA IfUAlUS OATt 1 bull raquof bull bull 1 ta
14 Hw rlaquo4 w bullbull bull 1 114 1mdash4 (llrl 1 1 1fl Hll
0 kmdash
Mraquo M4 raquo i T i 4 bullraquo-laquobull i i
Lgt f 1 21 S 1 Hbull - - bullbull -
ltJL 1 2 01 - - _ _ 1
mdash
-
1 12 _ Q I
mdash shy
mdash 4 (C ( - - fVi 1 - 0
1 (1
^ 1
Vvraquolaquo IJ1^ raquo CP O 3L 1 Z - i bull j-t-J
1 J
LH Vb T n 0
1 gt fl oo O ~l 2 L - bull 1 P )laquo jn iP IP - OOI L5L mdash shy
-t 84 ^(^^ ^fi P i flja 0 JO II 10 tl tcgt 7 J IV wllaquo
h l2L bull 0 lt -_ shy
-id VJ lt 3C 2 ft OOL -mdash
U 71 C1 Sr 2 13 2 nl JLJraquopound HP r M ltf1- (
IMe 2 ii O It
n jlt dl 1 1 bull o o-il ST i 1 i 25 2-x-1
-
ri
i tlL O mdash gtbull bullgtlt 1ft -o- is Oil So iJK 2-io otv u 31 fil loi 2 il Oll it Of wr is i1raquo -iZ 1 deg|0 01
M IT So - mdash
- 13 1 CT mdash i - mdash 21
shy
Tl Ci av ZUll IMT 0 IM Pe v _ 1) T) S) ii3( dlt Ii 2 lt^2 II li- S1 riivi To 7HX lt3lO 14 ^2- iTi I li 011 -- - -i -^IS no 5^ or i | T Jift laquoV OoH bullla It Va iCO mdash L OIL 11 bullvf poundgtpound lS_ flv oh P-lfe 1 poif _ shy11 IB kl (4 itlaquoT lamp llt0 oot^
mdash -n
It T1 |ir( L1 HI 2 0 oil
U 1M ft go C ICf^ -^2 Z laquo-|o
11 it 5 bulln - TO o abull Li u-i IT1 -- Iw O ltM (I bullbull bdquo-I(K 1mdash -tilltLlA ttfe
i Dgt ac -- U 44 4 11 1 1- ytd i i_i J-K 0 i if -i i i V t Wl raquoOHM 1-1 US D C P A R T M f N T OF COMMfRCE t 4 1 IUII 1 1 ^~) mdash
llaquo- Hi NC bull bullh bull bullJL^V HBl CO 00
11
)jLsVyr^gturv
^ | TKu
|-_t_ bull(
IIMgt I I Mt|UU III- II 11
PNECIPITATIOH
I 1 1 IMX
IMO
bull llfclaquo I UCIUKI) Ur C V A r U M A AHO CLIMATOUOCICAL OBitH
E V A F O R A T I C r i Jttffl laquo amp hMIlaquoJllaquoJIIlaquoBgt
DATE AOOITIOMAL DAIAKMAKk M
bullraquobullmdashlaquo
tp 01 (1 Of Ll OOI ooo
0^1 o-i 10 tl |00 102
OC (1 13 Ofl
it i rc DS os an
(1 SV o
Ul 010
(ISl 101 I on
130
II 5= Otl
ss lt 001 (IK Ml
jt il HIT
7 it
ow Wo 17 Top 2-01 OIO
(0 oov zi oot
u CO ^A 0 to Zoi CLflS
bull50 01 ljtj
nshy 5H LO OIt
50121 IVO QJO
14 Co Ho LO Hl ^pound Jl 1
ltM ool fllc
H Tl 01 II
11 11 Q1
iH OIO
HO 2 llaquol 11 II
lifc
IV-IIM ul OIPAITHINT or COHMIICC NOAA
NAtlOHAL gtIATnlaquoll raquotraquoVlClaquo CD
r~
All TCUMMATUNI ^V UII rgt ITmi 1 Cwphu Obic i gtn t ngir-H 30
rilCiriTATIOH
JJ T I rTJ-rimdashr-iramj|MP CLmATOLOQ
laquolaquo jftilCiii bullIHO
Oi1l ADOITIOHAL DAIAlllu
Ilf4ft
Sii1
(1 2 IO OO
Hl ii SO
us OIM
Q^L
a A3 Hi SZ Sf^ bull 12J2
HI Z-SF OOl 1C t HM IA H ICP fiJA
OOl 10 (310 sn 310
if HI (0 ^01
bullit SO 28H poundJ1 11 006
14 35 TX oon II (bull2 it zr II c-S
rr Zll lo 31 OP an 31 a 31 oor
CSW O-ll Si CC Of 011
Oll _ I |ft
00
u i oerraquolaquoTMiMr of c NOAA
NATIONAL K C A T N C M SCMVlCC
TC^S lk)oiVroTJA
TETT I 7X
1raquolaquolaquo 4 bdquo ir lt er ni I^OV ltqgl j--^ TQ
MICiriTAllOH ITIND
D|mdash
b5NO ctiUATOtoiCAL oeit^
OATI AOOITIOMAL OATAVlHAtt
0-tt
Mlaquoh bullbullbull- rshy laquo
I- ltltriu HI I 4 bulllaquobullbull1
Zii
30 Dfellt otvt
at HA
OOI
62
iJ_S2 HI if
bull- 20 SI 2i So
So
VVfr
OSfc
I (
Jtlt
3aoi
r j -bull ie MA
Irill iiol
in^ 14
Mo
Zll
214
21 1P
00-i
bulliron
17
bullr
11 i ir- I J Ktf^c
US D E P A R T M E N T OF COuMEDCC I | C gt A A
K AIlaquo Ttupf lATuit r
|SlVi AlJ PIICIPITATION
oJud (El
VIM i Uraquo
MIND E
EVAPORATIOH flnrft bull A ftufiifccdll
KECORO OF eVAPllHAtlil bull I CLIHATOLOOCAL OBSERVA ^Hij
14 MM A_M AOOIIIONAL DATA11 MAIM
Mr bullH Oo|
M Si lift
bull221 IHI
ZS Ji 40 IZV
icr KS I
HZ 111
bullT 21
loA UK JA IP
v^ ft
1M 2Sshy IT Tl
71 V |
i I 31 1deg a
uty^ U bull3
ons 1 CiO TxX
HHO (10
3H 19 12 10 IP
raquo3H raquo | 5t io
OP OIT
14
vO UI Of PANTMINI Or COMMCRCf MM O A A
F ngt TIHH
iiicffwiffc 4 rJ (TIM bull Cempltit Obitittiio
AIlaquo TIMHIATUM PHICinTATION I V A f OK ATlPrl
OATI ADDITIONAL DATA KMAlIt
U4laquo4 +
03H Ji
10
rc a 1 16 oi ii
tiiy 10
OI
II i23 or o 13 -y~ou HO
II 3V III i 3 t
V laquop oot
OM1 SS ne
T an -i IP
Olt zr LTV
3T 001
a -11 2T
10 an 31
-1 raquo 131 UP 3H lf 14 Lpoundshy
it 14 30
IS
Ui O I P A K T M f H T OP COWlf ICfM O A A
NATJONAI V C A T M C n f t K M V l C K
bullbullbullbullbullshy -2 o AIlaquo TIMMRATUM f fKICIPITATIOH
OATI poundt- MMINMAL DATAk
ZP 51 lo icr
011 111
OoT IHf
Ut 003 am
3o 13 ao
4A X 05shy
H4 i IjJyiV131 ooc js
IH oi 01 tL 18 13 a
No 11-7
rivgtp OO| M Hi 03 01
It 12
bull I 41 bull7119 14 ^^ raquo 31 15 lampk n M ho i
Jo -j-
-J
I
Ml H^ I _
amp2ampUi^= LS 0 S 0-f bullTTT
-Vmdash gt U_ bull 1 rOHM I- 11 OI OCPARTMlNT OF COMM(NCC
HO NATIONAL W f A T M f H ftfraquoVlCI
98
Appendix B
Boring Logs
99
X iHECT 1 ff 2
OAT American Drilling amp Bor ini I Co Inc
wo WATH smn EAST PR ov IDENC E ft 1 Town of South Kingstown South K ngstown R I MOLENO X-J
TC 100 RCSS bull ujrMonitorinq Well Installation | South Kinqjtown R I UNC a STA Pf KXICCTHJ LOC ATK3N
bull cfrserrr TO above S MPLES S FNTTO _ _ |laquolaquor A-109 SURF ELEV RE PORTSEr
GROUND WATER O6SE RVATC MS 1 CDREraquolaquo m-T nn75 laquo A 256 - 20 mdash Hew y
Instolled 32ofT-l2 PV C - JO- COMPUTE 111275 K toia 3- I-WI 1-38 TOTAL MRS bdquo10 screen BORING FCACUAM J K lanq MAI rraquo HomnwWI 300 140 IampPCCrc Mamlaquor Fall 24 30 lampaaiona SOLS ENGR
LOCATION OF BORING H ONITOKING WELL
Coung Samplt Tjp Blow per 6 Manure SOU IDENTIFICATION Strata SAMPLE ^^^yV Bloot
foot
Otptni
From- To
el
l
on Sampler
0-6 1 -6-13 12-18
Dentity or
Conmt j
Chang Remark include colo^ graaation Type of tod lie Rao-coMr type condition nordshynetiDntotf time leamt and tie No Pen Rtlt
2 No top sample 5 12
1 loamy fine sand
bull)^ 40 30 36
5- 616 0 23 20 16
noist iense
Brown fine to coarse SAND some fine to coarse gravel Trace silt
^
1 18 18
36 8-0shy57 40 30 V 35
|0-||-6 D 14 24 20 Srown medium to coarse SAND Some fine gravel cobbles
7 IRshy 16
27 75 37 3
IS- I- D 5 14 16 3bull
ISshy 15
42 50 I9--0shy50 65 20-2ll-6 D 9 23 26 bull Jrown fine to coarse SAND Tbullwshy 1Z 75 90
22-0 Trace silt trace fine gravel
124 120 74 60 52 41
7S-ltlaquoil-A DX 71 16 13 wet very dense
Gray-brown fine to coarse SANC Some fine to coarse gravel little silt
H IR u
40 30--0
3C-30-IO
3l4-334
334-3314
38 4-434
D
c
C
C
7 IflO
94 6
we tr j
y se
ft irox
30MOshy
31 -4shy
Gray-brown fine to coarse SAND Trace silt
Gray-brown fine SAND some lilt trace fine gravel
Too of Rock 31 -4shy
Gray-pink GRANITE
6 7
amp
CJ
IltJ A
60
601
IQ mdash
2(
4
5 i Hard
ft 5ome seams bull
GROUND SURFACE TO J 4 U3CD_ ^JVrf bullbull( tutu t to 4o 4 SampM Type Proportion UMd MOB Wtx 3 OfaM on 2OD Sampler SUMMARY-
OOry CCartd WltWen4 Hoc OlolO Canmonieraquoi Don any CoKeem CarMWncy Earm Barrlaquoj 11 14
UPgtUnOigtturod Piuon trite (Oto20dego 0-Kgt Loei it 0-4 Sait 3O+Hofd Rock Corng 14 Kgt-30 laquo4 0 rte 4-8 MSHM Samplet TPTtitPit Ai Auger Vvanefett tarn 2Olo39 3O-M Owlt n laquo-lS Strlf rinit nn v 1
UTiUndlshffbed ThrMOll and bull 33to9O 5O Very 0laquo nraquoe 19-30 V-3trraquof - | OLE NO X-l
TOVH rim - iA it raquotoraquo
100
SHEET 2 o_L
WO WATEt STUET [AST ft OVIDENC pound a i American Drilling amp Bor ing Co Inc
MCLl WQ X- 1 Tt AOORCSS i
LIME A STA KXICCTMJ tuf same as 1 | tame as i LOCATION
W PORTSEf mo OB nj urt eflaquo T
illtPLES S
P
CVTTO nlaquo mun orv
^s f^ Tin i GRCVMO WATER OBSERVATONS CASING SAMPLER CORE BAR
START Typi COMPUTE tome at 1 same aiH
TOTAL MRS BORIMG FOR CMAN n bull IT INSPECTOR SOILS EMM
LOCATION OF BORING u HfVJTneTfi UFI _
8
Counf Blo-t
foot
Dtpllo
From To
0( on SampMr
0-6 f 6-IZ
Moittir
Oonuty or
Contilt
Strata Ctnngc
SOIL OCNTiriCATION Rtmorkt ineHifl cotot grqdotion Typlaquo of Mil etc Roo-axtrPlaquo condition Mrdshynlaquot Drog tun ttomt end tic
SAMPLE
No Ptfl RfK
434-4o4 c
approx 7 minj
per toot 454
Gray pink GRANITE Hard Fairly solid core
lt_4 24
Bottom of Boring 45 -4
-
~
bull 1
GROUND Sorrow Tye
SURHCZ 10
bull OiOry CgtCord WWothod UPUnditiurMd Piston TPlaquoTtraquotPtt AtAuotr VVor
UTltUndinrvd TTMMO bull bulltat
iivnPilaquo(onioni Uraquot4
me OioiOItttt laquoraquo20
wmt Z0ie33
and 361090
c M
C1 5 Si
-SOshy
ASING
IOtgtWtigt bullnlot Dn 10 Loci M Mod 04 SO Dm 1shy Viry 0laquo
s _
TMEN 0 hMl on 200 SoiTBUr laquoity ConcMMt Conorawncy gtbull 0-4 Sort 30shym 4-B MStlfl M BH9 Strtf bull ts-so v-swt bull
t-HOrt Ear Bern RoetCorrt
i ^^^^^ bull
-[MOLE no x-i
101
raquoMEC rAmerican Drilling amp Bor in g Co Inc 1 ofj_ DATE wo WATlaquo smn UST Plaquo IOIDCNC j laquo i
Town of South Kingstown South Kingstown 8 MOLE MO Jlt Z TC rx MCS3
rtprr uAurMonitorina Well Initollation | South KinqitowrxRI UNC A STA P KATIOM ME POCT ^rwT TO above I OFFSZT
uD^r laquorlaquorTTO 6 -109 suw tLEv Sgt louffJOCNO
0 tj Tlmlaquo WOUND WATER 06SCRVATC US gtW Rsdl SING SAM^EH CORE BAH
26 ^_ 12 $TAlaquoT UL 2Z2i Ji r TTP NW ltA sr IJZC Z5 CCOMPLETE
SitLO 3 I-3B- 1-38 TOTAL MAS 41 BOAINO FOACMAN JK1 ana nf ni n MonwwWl 300^ 140 BIT bullK^CT
gttonvrar Foil J^laquo 30mdash Diamond SOOJIEMGM
IE HFII
iCaunq SampM Trplaquo BMMtpw6 UOIIIK- SOIL DCMTIFKATION Siraia SAUPLE Blow DlaquoPIAraquo of on SompMr HtmorU mcJuo cotes gradation Type of Dwuily
pw or CXang writK Roel-eolorlyp condition tvort-From- To Vfoot 0-6 f 6-2 12-18 Coniitt egt rwtiOnAngtimt wamaondtte No Praquon Rtlt
2 Brown fine SAND little silt 2 2-0shy5 15 18 moist Browi fin to coarse SAND 18 5- 6-6 0 14 25 27 vlaquo Troc fin aravel | 25 wy Ifl 11
dlt tns 35 40 38 moist n in-il-i Lgt U 15 18 ie is li1 Irl IS 31 I2-0
~~43 1
A) Jrown coars to medium SAI MD 48 moist Little fine to coarse gravel
|5-IA-Xlaquo 14 47 41 fn D laquo y Little silt rrqa coarse sane 3 18 I1
68 In IS 44 32 34
n ^n-^i-A- w 2o 19 29 wet 4 la -59 lens ltfO no
25-0 2amp bulllaquo- 77 c BOULDER r[ 4 i
27-0 5X ~W 24 24 bullWar- 5 Ifl irown tine to coarse SAND some
dens 29-0- Fine-coars gravel trace silt
30-3I oxx 30 32 30 moist irown -gray fine SANDiom e 6 l rr Vlaquoy 31 -0 silt trace fine oroveTILL
Bottom of Boring 31 -ampbull shyBent casing -pulled out and moved over 4 - washed amp tJrovlaquo casing to 30 -Installed 3C gtof 1-12- PVC - 10 screen
WOUND SUraquoraquofCE TO 3pound 1 yijfD MW t ASIMC TMCJ laquo olaquorod -bor of borina
SomoU T]Fplaquo ProigtuliOraquoH UMd MIOtgtWLx3Orolt lon2OASanlaquoMr SUUMARY-D=Dry CCorad Wlaquoworaquonraquod bullact OiaiO CanM gnMM Daonty CIMIH Caamraquoci EffW 8or^ 2pt
UPiUnairurMd Pition Itnt laquoM2O O- O UKraquolaquo 0-4 Soft 3O-hHard Roelaquo Corrig o- JO M0mlaquo 4-8 MSNff SOTipM 1 p^ 3O-9O OwgtM bull-IS Slid
TPlaquoTraquojraquoPit AAugtr ViVon mini tamt 20to39 UTtundiifir6d TrwMOtf and JSloSO 50-raquobull Vary 0nlaquo [HOLE NO x-2 B-3O V-3Mf lev rim - IAIT raquosectlaquoraquo
102
300 iu 24
1 UMnii ffi 140 laquo 30
CA1INC tf
gt taWCTf
bull 0gtlaquo i R Cook Jr_ R Millineton1 Wttn
I~
1 VAMtl CtMG
1 W HO-t MO
1 Oraquo 1 laquo0~ twt
L 1 laquo-raquo VfcM^lf [wlaquoraquoCI ^ ^ K3Ot III laquo
0-LS D
5-65 D
LlQ 10-115 D
15-16 Tgt
Lraquo 70-51 n
25-26 D
F
I O-O Ci
A Allstate Drill ins Co vi o i
PROVIDING R 1bull raquoraquo uvraquonn~ N M O M I T O P I N G HE1 _^lt -^ PI-Traquo UJU
CUM Town of South Kineraquotown raquoraquo 1 1TA maoer Propolaquolaquod Sit for Slude Disposal nltn
laquo V-449 iampAAtut i a 138 ort STI bull r 42777 CtOuMO IKVtllON
Cill bdquo 258 DA II MN ru 42777 rilaquolaquodO laquoraquoTti rum 1911
AU1TATI
MMUI1 raquolaquogtlaquolaquo laquoKiO itXHHKraquoriOi of sous MUAHI nMTKlion Ot CMlaquoMC|kOraquort tl CO~VH DXltgt raquomlaquo laquotf IMi COIOI C4l II I 1raquo gtlaquo^ Oraquo 1Ol rC t Xgttgt VtfKOe Craquo Mi 1 ft liMraquoK laquo0^tlaquot nfgt
1-2-1 10 TOP SOIL FINE LIGHT BROWN SAND traclaquo of ilt
16-31-17
22-24-21 100 FINE TO MEDIUM LIGHT GRAY SAND trace of fine gravlaquol and raquopoundLt
lfl-37-34 150 LIGHT BROWN FINE TO MEDIUM SAND little poundinlaquo gravel
21-17-15 200 MEDIUM TO COARSE SAND bullomc fine gravel
12-4-10
265
Observation well installed
NOTE No casing blows taktn
bullbull B-23 ow
^w^ 265 I raquo bull raquolaquo bull I W
11 laquot gtbullraquo Vlaquo 14 W gt_ c-shyji bull alaquo bull jraquo VI laquoHshyw bullbull m raquobullbull D-6 raquo Mshy
bull bull laquo Vshy
1
bull bull
I
103
MAMMII Allstate Drilling Co ulaquorr 1 or 1 FftOVIOCKZ H L traquolS mTArm^S MONITOR NR WEL
VNO wr3JJO__raquoraquou_24__ HCU MO P-74 n iu riBwi Town of Slt7H^ Xirpin
mdash^ laquo0J P 1 1 bull ^n^ciit^o TVlaquow^laquott1 bullraquoit wt 140 nu 30 olaquor fBu lkv Waste Disposal Arcai
MUTAH a V-449 R Cook Jr UMlaquoiigti D 1 38 0t| raquoIJ raquo 5277 rlaquo SUMO luvlaquorv-laquow
mdash 5277 fipe -raquoT pfpm 150
H MCIO IMNTlXAflON Of SOU t(kAIlaquoS rrn 0-laquoraquo
5 -SF 01 w in laquobull -raquo ^ lit
D 1-2-2 TOP SOIL V-1-oraquo
15 IPbull FINE TO MEDIUM LIGHT GRAY SAND AND GRAVEL
5-65 D 37-27-35 some silt
10-11 D 20-14-18
15-165 D i 17-14-14 155
BROWN COARSE TO MEDIUM SAND little fine to coarse gravel trace of silt
20-211 D 4-4-2
230 GRAY BROWN VERY FINE SAND
25-26J D 7-8-9 AND SILT 265 fvarvedl
Observation well installed
NOTE No casing blows taken
wta 10 n uuraquo c^imdashbull IgtM laquolaquobull- B-24 ow ~ 14 ltfc laquoraquobull vlaquo^ M laquobull r O 0 fmtt bull W-L 26 5
-0- CgtCmdashgt bull laquolaquobull mdash laquo 1 - raquoraquo 1 gt 1laquo bull 1 gtraquor to bull mdashbull bull bull bulllaquo I t l~laquo 1lt Uraquo mdashbull ) bull 1 gtbull ft 0~ H laquoy bullM ta bull -IN la laquobull OPUM bull($ IMI
mdash H raquo laquo-bull
104
Appendix C
Calibration of Specific Conductance Meters
105
Specific conductance measurements were made using a beckman RB
338 temperature compensating meter and a YSI rtooel 33 salinity
conductivity temperature meter The YSI meter is not
temperature correcting A formula to compensate for temperature
differences to standardize YSI measurements was used (21)
A long probe for the Beckman meter was used to measure conductivity
in the wells Differences in conductivity between the YSI ana
Beckman meters and the Beckman short and long probes exist These
were calibrated in the laboratory using 001 N and 01 N KC1
solutions Values presented are Beckman short probe values The
Beckman long probe values were reduced by 76 and tne YSI values
were multiplied by 11 to adjust to Beckman short probe values The
YSI meter was used in the latter phases of the study for the
stream contamination due to the greater accuracy of the dial readout
scale
Table 7 Specific Conductance Meter Calibration Table
Concentration (KCL) 0001N 001N
Specific Beckman short 145 143 143 1247 1245 12GO
Conductances Beckman long 190 191 188 1639 1650 1665
umhocm 9 25 C YSI 132 131 128 1131 1140 1150
average values Beckman shortBeckman long = 075
Beckman shortYSI = 11
106
Appendix D
Computer program Flow Chart
107
F1g 33 Computer Program Flow Chart-
1TpoundR MAP TCO
NEWPER
WEWSTP CZAX
HEWIT TRANS TCOF ROW COLUMN
Yes
Yes
108 The following is a description of the USGS two-dimensional computer
program Iterative Digital Model for Aquifer Evaluation updated
December 1972 by P C Trescott The program written in Fortran
consists of a MAIN program and six subprograms or subroutines which
themselves are organized into subprogram sections The subroutines and
their sections are listed below
MAIN Program
DATAIN (subroutine) COEF ITER (section) CLAY MAP TRANS NEWPER TCOF
ETRATE COMPUT STORAG
NEWSTP LEAKAG NEWIT1 NEWITO CHECK ROW CWRITE COLUMN STEADY PRNTA OUTPUT DRY BLOCK DATA
The program begins in the MAIN program which controls the sequence
of passage to the subroutines Sequential steps are described in the
program as shown in the flow chart of Fig 32 Emphasis is placed on the
steady state confined aquifer case as applied in this study First data
input is read in the DATAIN subroutine This data includes transmissivities
or permeabilities starting heads storage coefficients and grid spacings
Nodal transmissivity values are then computed for the water-table problem
in the TRANS section (COEF subroutine) This procedure is necessary here
because the subsequent routine for computing iteration parameters (ITER)
keys on nodal transmissivity values which would not have been input to
the water-table problem In the water-table option these would have been
109
computed from given bedrock and water-table elevations to obtain the
saturated thickness component of the transmissivity calculation In this
study water-table option was not used and the transmissivity values were
input directly The program then passes to the ITER section (DATAIN
subroutine) to compute the iteration parameters which expediate or even
cause convergence Next the MAP section (DATAIN subroutine) is utilized
to initialize data for an alphanumeric map if this was requested in the
input options Transmissivities are then computed for the confined
(artesian) aquifer case (water table not specified with input options)
in the TCOF section (COEF subroutine) These coefficients are harmonic
mean values of adjacent nodal transmissivities weighted by grid sizes
Time parameters and pumping data for a new pumping period are then read
in the NEWPER section (DATAIN subroutine) followed by entry into the
NEWSTP section (COMPUT subroutine) which calculates the size of the
time step Leakage coefficients (hydraulic conductivity of the confining
bed divided by confining bed thickness) are next computed in the CLAY
section (COEF subroutine) if leakage was specified in the input data
which was used in this study
A new iteration is then initiated in sections NEWITO (COMPUT
subroutine) NEWITO saves the current head values and compares them to
the updated head values for determining closure This is followed by
nodal transmissivity values being computed for the water table or water-
table artesian conversion problem Transmissivity coefficients are then
computed for the water-table problem in TCOF (COEF subroutine) Total
head values are then computed with the alternating direction implicit
procedure using the Thomas algorithim first along rows in the ROW section
110 and then along columns in the COLUMN section both in the COMPUT subroutine
Then if a solution is not obtained (because the error criteria for
closure is not satisfied) the MAIN program branches back to NEWIT1 subshy
sequent sections TRANS TCOF ROW and COLUMN repeatedly until a
solution at the particular time step is achieved NEWIT1 increments the
iteration counter and is immediately followed by NEWITO The program then
moves to the STEADY section of the COMPUT subroutine to check if the
closure criteria for steady state has been satisfied Output is then
printed in the OUTPUT section of COMPUT if steady state has been reached
or if the particular time step is designated for output
The program then branches back to NEWSTP (COMPUT subroutine) and
moves through the subsequent routines until the last time step in the
pumping period is reached Output is then promoted in the DRY section
of COMPUT if specified in input data If the last pumping period in
the problem has not been reached the program branches back to the
NEWPER section and moves again through subsequent sections otherwise
the program will terminate or start a new problem if one follows
This study was simulated as a steady state problem which can be
simulated by setting the storage coefficient of the aquifer and the
specific storage of the confining bed to zero and using one time step
of any length
111
Appendix E
Computer Data Sheets
RGSEA
10 ROSE HILL LANDFILL MODEL 20 30 40 LEAKAGE 50 60 70 CHECK 80 90 100 HEAD 110 120 1 23 IQ 100 5 001 37E-OU 0 130 100 001 0 0 1 4 0 - 1 - 1 1 - 1 - 1 i i i i i i 1
ISO 1 10 0 1547E-05 01 10 1 1 160 04642 200 200 1 1 i it
1QO 190
CARDS I THROUGH 19 - CODING SHEET
CHEAD
100 110 120 130 131 132 140 141 142 150 151 152 160 161 162 163 164 165 170 171 172 173 174 175 176 177 178 179 1BO 101 190 191 192
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 539
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 58
25
25
25
25
25
25 621
25
25
25
25
25 662
25 25
25
CARD SET 2 - STARTING HEAD MATRIX (FT)
193 194 IVb 196 197 190 200 201 202 210 211 212 220 221 222 223 bull 224 225 230 231 232 233 234 235 236 237 23B 239 240 241 250 251 252 253 254 255
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 23 25 25 25 25 25
25 25 - 25 25 25 25 25 25 25 25 25- 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 - 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25
25 25
25
25 25
25 25
25 25
25
25 25
25
25 25
25
25
25
25 25
25 25
25
25 25
25 25
25 25
25
25
25 25
25
25 25
CARD SET 2 - STARTING HEAD MATRIX (FT) - continued
STORC 1512 FRI 19 FEB 82
100 110 -1 -1 - 1 - 1 0 0 120 130 140 ISO 160 170 100 190 200 210 220 230 240 230 251 260 261 262 263 270 271
CARD SET 3 - STORAGE COEFFICENT
LEAK
100 110 120 02 130 _ 18 02
I ltu 18140 025 150 02015015015 19 deg25
02 160 022 bull-laquo- J1 5 j 1 z laquo- l^
170 015 180 016 laquo02
190 016 OE025
200 02504019022021025 2 5 i S lt03 0252i2 n
230 030 deg23 deg2 deg2 deg2 -02023023 240 022 250 022025025 02
027043 013025
30() 025025025 310 025031 320 024025
CARD SET 5 - AREA OF STEAMBEDAREA OF NODE
120
Appendix F
Bibliography
121 BIBLIOGRAPHY
1 Agpar MA and 0 Langmuir Ground-Water Pollution Potential of a Landfill Above tne Water Table Groundwater V 9 No 6 1971 pp 76-96
2 Allen William B Hahn GW and RA Brackley Availability of Ground Water Upper Pawcatuck River Basin Rhode Island USGS US Government Printing-office GS 66-624 19bb
3 Annual Book of ASTM Standards Part 31 Open Channel Flow Measurement of Water and Waste Water by Weirs D 2034-68 1975
4 Annual Book of ASTM Standards Part 19 Infiltration Rate of Soils in Field Using Double-Ring Infiltrameters D 3385-75 1975
5 Baeaecner MJ and W BacK Hyarogeological Processes and Chemical Reactions of a Landfill Ground Water V 17 no 5 1979 pp 429-437
6 Beck WW Dunn AL and Grover H Emrich Leachate Quality Improvements After Top Sealing1 8th SHwRD MERL Symposium 1982
7 Beckman WK Transient Modeling For Estimating Sustained Aauifer Yield master thesis presented to the University of Rhode Island Kingston RI 1978
8 Bhattacharya PK and HP Patra Direct Current Geoelectric Sounding Elsevier Publishing Co New York 1968 135 p
9 Bouwer H Ground Water Hydrology McGraw-Hill Book Co New Yoric 1978 p 378
10 Braids 0 Cocozza pound Fenn D Isbister J Rous P and B Yarc Procedures Manual for Ground Water Monitoring at Solid Waste Disposal Facilities Environmental Protection Agency530SW-611 Cincinnati Ohio 1977
11 Cartwright K and MR McComas Geophysical Surveys in the Vicinity of Sanitary Landfills in Northeastern Illinois Groundwater V 6 no 5 1968 pp 23-30
12 Cartwright K and Fd Sherman Jr Electrical Earth Resistivity Surveying in Landfill Investigations Reprinted from Proceedings of ohe lOtn Annual Engineering and Soils Engineering Symposium Moscow Idaho 1972
122 13 Clark TP Survey of Ground-Water Protection Methods for
Illinois Landfills Groundwater V 13 no 4 1975 pp 321-331
14 Dunne T and LB Leapold Water in Environmental Planning WH Freeman and Company San Francisco 1978
15 Faro DG Upgrading Hazardous Waste Disposal Sites Remedial Approaches US Environmental Protection Agency500SW-677 Cincinnati Onio 1978
16 Fenn DG Hanley KJ and TV Degeare Use of the Water Balance Method for Predicting Leachate Generation From Solia Waste Disposal Sites US Environmental Protection Agency530SW-lfa8 Cincinnati Ohio 1975
17 Geisser 0 An Electric Analog and Digital Computer Model of the Chipuxet Ground Water^ Aquifer Kingston Rhode Island master thesis presented to the University of Rhode Island Kingston RI 1975
18 Hahn GW Groundwater Map of the Narragansett Pier Quadrangle Rhode Island Rhode Island Water Resources Coordinating Board GWM 5 1959
19 Hemsley William T Koster C Wallace Remedial Technique of Controlling and Treating Low Volume Leachate Discharge USEPA National Conference on Management of Uncontrolled Hazardous Waste Sites Oct 1980
20 Hughes GM RA Landon and RN Farvolden Hydrogeology of Solid Waste Disposal Sites in Northeastern Illinois Final Report to US Environmental Protection Agency PUD SW-l^d Cincinnati Ohio 1971
21 Keller GV and FC Frischknecht Electrical Methods in Geophysical Prospecting Pergamon Press New YorK NY 19bb
22 Kelly WE West Kingston Landfill An Evaluation of Its Effect on Ground-Water Quality Rnoae Island Water Resources Board Water Information Series Report 1975
23 Kelly WE Geoelectric Sounding for Delineating Ground-Water Contamination Groundwater V 14 No 1 1976 pp fa-10
24 Kelly WE Ground-Water Pollution Near a Landfill ASCE Environmental Engineering Division Journal V 10 No EE6 Dec 19b pp nay-nyy
25 Kelly WE personal communication January 1982
123
26 Kelly WE and OW Urish A Study of the Effects of Salt Storage Practices on Surface ana Ground Water Quality in Rhode Island NTIS FHWA-RI-RD-8001 1981 54 p
27 Kimmel GE and OC Braids Leachate Plumes in a Highly Permeable Aauifer Groundwater y 12 no 6 1974 pp 388-393
28 Klefstaa G Senalein LVA ana RC Palmauist Limitations of the Electrical Resistivity Method in Landfill Investigations Groundwater V 13 No 5 1975 pp 418-427
29 Landon RA Application of Hydrogeology to the Selection of Refuse Disposal Sites Groundwater V 7 no b 19b9 pp 9-13
30 Lang SM Bierschenk WH ana WB Allen 1960 Hyaraulic Characteristics of Glacial Outwash in Rhode Island Rhode Islana Water Resources Coordinating Board Bulletin No 3
31 LeGrand HE Patterns of Contaminated Zones of Water in the Ground Water Resources Research v 1 No 1 1965
32 Palmauist R and L Sendlein The Configuration of Contamination Enclaves from Refuse Disposal Sites on Floodplains Grouna Water v 13 no 2 1975 pp 167-181
33 Pinder GF A Digital Model for Aauifer Evaluation Techniaues of Water Resources Investigations of the US Geological Survey Bk 7 Cl 1970
34 Purushattam D Tamxe GR and CM Stoffel Leachate Production at Sanitary Landfill Sites ASCE Environmental Engineering Division Journal V 103 no EE 6 Dec1977 pp 981-988
35 Remson I Fungaroli AA ana AW Lawrence Water Movement in an Unsaturated Sanitary Landfill ASCE Sanitary Engineering Division Journal v 94 no SA2 April1968 pp 307-316
36 Rosenshien JS Gouthier JB and WB Allen Hydrologic Characteristics and Sustained Yield of Principal Ground-Water Units Potowamut-Wickford Area Rhoae Island USGS US Government Printing Office GS 67-324 1968
37 Roux PH and B Vincent Electrical Resistivity Evaluations At Solid Waste Disposal Facilities US Environmental Protection Agency SW-729 Cincinnati Ohio 1978
124
38 Salvato JA Wi lk ie WG and BE Mead Sanitary Landfill Leaching Prevention and Control Water Pollution Control Federation Journal v 43 no 10 Oct 1971 pp 2084-2100
39 Sawyer CN and PL McCarty Chemistry for Environmental Engineering McGraw Hill 1978
40 Stellar RL and P Roux Earth Resist ivi ty Surveys - A Method for Defining Ground-Water Contamination Ground Water v 13 no 2 1975 pp 145-150
41 Todd OK Ground Water Hydrology John Wi ley and Sons Inc New York 1959
42 Tolman AL Ballestero AP Beck WW and GH Emrich Guidance Mannual For Minimizing Pollution From Waste Disposal Sites US Environmental Protection Agency-500SW-677 Cincinnati Ohio 1978
43 Trescott PC Iterative Digital Model for Aauifer Evaluation US Geological Survey Open file report 1972
44 University of Rhode Island Academic Computer Center CalComp Contouring Manual
45 Warner DL Preliminary Field Studies Using Earth Resistivity Measurements for Delineating Zones of Contaminated Ground Water Groundwater v 7 1969 pp 9-16
46 White EF A Report to the Town of S Kingstown Utility Survey Engineering Corp 1967
47 Zohdy AAR A Computer Program for the Calculation of Schlumberger Sounding Curves Over Horizontally Layered Media Using the Method of Convolution US Geological Survey Denver
48 Zohdy AAR Eaton GP and DR Mabey Application of Surface Geophysics to Ground-Water Investigations Technidues of Water-Resources Investigations of the US Geological Survey Book 2 Chapter 01 Washington US Government Printing Office 2401-02543 1974
TM
Thesis Abstract
The South Kingstown Lanafill is located adjacent to Rose Hi l l
Road approximately one mile north of Peace Dale Rhoae Island
Refuse has been deposited above at and below the water table in an
abandoned gravel auarry since 1967 No grouna-water protection
measures were taken to minimize pollution of the surrounding highly
permeable aauifer material Contamination in some neighboring wells
and in streams to the southwest and east of the landfill has
occurred This study analyzes the present situation by
investigating the areas geohydrologic characteristics grouna-water
flow patterns and contaminated zones Use of seismic refraction
surveys boring logs the USGS ground-water map ana monitoring wells
helped define aauifer geometry ana flow patterns Specific
conductance was measured in monitoring wells ana streams as an
indicator of contamination Electrical resistivity was used in a
known contamination zone The USGS Iterative Digital Moael for
Aquifer Evaluation is used to simulate conditions in the study
area evaluate possible remedial control solutions and make
recommendations
IV
Preface
This thesis is written according to the Standard plan The
Table of Contents lists sections included in the Main Body of
the thesis The Appendices include relevant material that is
referred to in the thesis Main Bodyand a Bibliography
Table of Contents
Page
Title Page
Approval Sheet
Acknowledgement ii
Thesis Abstract iii
Preface iv
Tab I e of Contents v
List of Tables vi
List of Figures vii
Main Body
Introduction 1
Background 2
Description of Study Area 10
Field Studies and Procedures 15
Model Development 30
Model Calibration 41
Computer Simulations 42
Analysis ana Discussion 55
Remedial Measures and Recommendations 75
Conclusions and Recommendations 83
Appendices
Appendix A Precipitation Records 86
98
Appendix C
106
Appendix E
120
Appendix B Boring Logs
Appendix D Computer Program Flow Chart
Appendix F Bioliography
CaliDration of Specific Conductance Meters in4
Computer Data Sheets Ill
VI
List of Tables
Table
1 Well point Water Elevations 17
2 Seismic Refraction Survey Results 20
3 S tream Fl ows 22
4 Specific Conductances in Well points 26
5 Specific Conductances in Streams and Observation Holes 27
6 Schlumberger Vertical Electrical Sounding Results 27
7 Specific Conductance Meter Calibration Table 105
Vl l
List of Figures
Figure
1 Location Map 2
2 Study Area 3
3 SupplyWel l Locations 4
4 Field Grouna-Water Table Contour Map 5
5 Ground-water Map 12
6 Geology Background Map 13
7 Fluctuation in Water Level in W e l l s 16
8 Seismic Survey Location 19
9 We i r Locations and Water Level Ranges 21
10 Surface Contamination Monitoring Locations 24
11 Fluctuation in Specific Conductance in W e l l s 25
12 Electrical Resist iv i ty Sounding Location 28
1 3 Model Grid 31
14 Simulated Ground Water Table Contour Map 32
1 5 Northern Drainage Area 34
16 Landfill West-East Cross-section between Wells W and EC 39
17 Landfill North-South Cross-section between Wells NW and SC40
18 Natural Conditions 43
19 Excavation without Landfill 45
20 Landfill without Excavation 46
21 Landfill Head Contour Cross-section 47
22 Landfill and Excavation with Dam 49
23 Summer Condition 52
24 Landfill ana Excavation without Dam 54
VI 1
25 Infiltrometer Location and Drainage Feature 57
26 Results of Infiltrometer Tests 59
27 Schlumberger Sounding R-l 71
28 Schlumberger Sounding R-2 72
29 No Recharge over Lanafill 77
30 SI urry Wall 80
31 Slurry Wall without Recnarge Over It or Landfill 81
32 Precipitation Record 87
33 Computer Program Flow Chart 107
Introduction
Ground-water contamination of aauifers from municipal landfills
is a widespread problem Contamination of domestic supply wells and
neighboring streams has occured at the South Kingstown municipal
landfill which is located adjacent to Rose H i l l Road approximately
one mile nortn of Peace Dale Rhode Island (Fig 12) The polluted
neighboring wells have been relocated to their present locations to
remove them from tne leacnate plume (Fig 3) Fig 4 inaicates flow
patterns from the landfill which has contaminated streams to the
east and southwest of it The generation of leachate continues as
precipitation recharge and upgradient ground-water sources
infiltrate the refuse To effectively prevent or minimize
contamination from this landfill several remedial options are
available These w i l l be evaluated relative to the areas geologic
setting and hydraulic properties ground-water flow patterns
recharge characteristics and proximity to supply sources
The rate of ground-water flow out of the landfill into the
adjacent aauifer and flow patterns largely depend on tne hydraulic
gradient of the water table and the hydraulic conductivity of the
landfill and aduifer material The hydraulic gradients were
determined by monitoring water-table fluctuations in several wells
located around the landfill and elevation siting in stream
locations and elevations This information enabled a ground-water
map of the area to be developed from where flow patterns can be
developed assuming flow lines are orthogonal to contour lines The
ground-water map in combination with Knowing aquifer and landfill
N
^ooo
feet
Fig 1 Location Map
3
peoy ||H asoa
X ltbull
Alt
f c c
o
^ ^ o o f a
O OJ 83X1
o O
x o
seepage observation -t West
hole Landfill Area
Legend mdash landfill limit bull j--excavation limit r^-s stream copy WNWNEECSeuroSCSEN
monitoring well locations = = = unimproved road
A contaminated domesti supply well
D uncontaminated domestic supply well
feet
Fig 3 Supply Well Locations
5
a 03
N lo ^ gt
laquo c 2
mdash w
3
X o ^
3 O L
o CO
0 opound E bullo
0
co
c
o0
uj ^
0 o o c
o $ bullA
E c o
w
bullo t_hraquo9 O
_OplusmnJ ca
u
pro
ve I 51 H
bullo 0gt
UJ _c e poundbullo Mzbull w gt 0
laquorege cc
0gt -^^ o a5 raquobull bullo o sect 3 mdash laquoo o wcz _
3Ogt c $c o_ X
aw e 05 0 (0 3 bullo
o a 2 2 u
hydraulic properties and the subsurface geometry enable estimates of
ground-water outflow to be made Streamflow measurements were used
to verify these outflows Contamination levels using specific
conductance measurements as an indicator were measured in wells
streams and observation holes to help delineate the extent ana
degree of contamination An electrical resistivity sounding was
conducted in a known contamination zone
The primary objective of tnis study is to determine flow
patterns in the vicinity of the landfill ana recommend possible
actions to contain or minimize the impact of the contamination In
oraer to fully evaluate these goals the aforementioned parameters
were input to a computer model to produce simulated flow patterns
under different conditions The simulated present conditions were
matched with field water table and stream flow measurements to
calibrate the model A series of simulations were then run to
evaluate flow conditions before the excavations anaor landfill
existed Remedial measures such as reducing recharge to the
landfill and implementing a slurry wall to blocx off leachate flow
to endangered wells were simulated to evaluate their effectiveness
Based on this analysis recommendations are made as to how to
minimize leachate production ano best alleviate the immediate danger
of the contaminant plume spreading to unpolluted domestic supply
wells
background
The South Kingstown landfill is in a geologic setting that is
very similiar to the nearby West Kingston landfill This is located
about 3 miles west of the South Kingstown landfill and has been
studied to assess leachate effects on groundwater quality using
specific conductance as an indicator of contamination levels
(222ltt) Both sites were located in abandoned gravel Quarries which
were filled in with refuse to create the landfill
In the literature numerous authors have shown that the character
of contaminant plumes from landfills are largely dependent on the
local geology and geohydrology A study on Long Island (27) in
similiar glacial material illustrates that the Quantity of flow is
dependent on the hydraulic conductivity of tne aauifer the
hydraulic gradient and the vertical cross-sectional area of the
aauifer it flows through This is expressed as Darcys Law (41)
Q = KIA
wnere Q = flow quantity
I = hydraulic gradient
K = hydraulic conductivity of the aauifer
A = vertical cross sectional area of the flow area
Specific conductance was used as a contaminant tracer to show that
the plume from the landfill flowed downgradient and vertically
through the full thickness of the aauifer A study in Iowa (32)
indicates that the size ana shape of the contamination outflow from
a l a n d f i l l can be predicted from existing geohydrologic conditions
and that the horizontal shape of the outflow extends downgradient
8
from the source and parallel to ground-water flow lines Other
parameters which control the extent of the contaminant plume are
dilution and dispersion in the aquifer and the adsorption properties
of the aauifer material (31)
The amount of leachate generated depends largely on the amount
of water that infiltrates through the landfill to increase tne water
content of the refuse in the landfill The precipitation recharge
that percolates down through the unsaturated zone to the water table
moves in a vertical direction (35) Surface runoff soil moisture
storage losses and evapotranspiration account for tne precipitation
that is not transmitted tnrough the unsaturated zone of aeration
(3315) Upon reaching the saturated zone the water enters the
ground-water flow system Ground-water mounding has been reported
in landfills due to the decreased hydraulic conductivity of
compacted refuse relative to surrounding aauifer material (20)
Chemical processes within the landfill leachate outflow and
surrounding soil cation exchange capacity relative to water duality
of the surrounding aduifer have been studied in Pennsylvania (1) anu
in Delaware (5) A procedures manual for ground-water monitoring at
solid waste disposal facilities was developed by the US
Environmental Protection Agency (USEPA) (9)
Several reports have been written that investigate site
selection design criteria and remedial measures to correct
leachate problems (29) A survey of ground-water protection methods
for landfills in Illinois studies relationships to the water table
theory of liner installation and monitoring devices (13) Sanitary
Landfi11-Leaching Prevention and Control presents a review of
preventative methods such as means to minimize infiltration
interception of ground-water and other pollution control measures
(2 37) A study in Pennsylvania on actual measures implemented to
collect and treat a landfills leachate discharge presents a site
specific study (19) Leachate Quality Improvements After Top
Sealing1 shows that by minimizing infiltration at a landfill in
Connecticut the outflow leachate water quality can be improved
dramatically and contamination plume reduced significantly (6) The
most comprehensive reports on remedial approaches to upgrading waste
disposal sites and ground-water protection methods have been
compiled under USEPA contract (1542)
To assist in evaluating remedial measures the US Geological
Survey (USGS) computer model Iterative Digital Model for Aduifer
Evaluation was used It was originally developed as a model for
simulating two-dimensional aauifer problems (33) It had been
updated since its original development to accomodate different
options (43) This model has been applied to glacial outwash
regions in Rhode Island (717)
10
Description of Study Area
A map of tne landfill area (Fig Z) was obtained from tne town
of South Kingstown The excavation to the west of Rose Hill Roaa
the landfill area directly to the east and the presently operating
area to the east of the central stream comprise tne overall study
area This study will concentrate on the west landfill area whicn
has recently reached capacity and been closed to further dumping
This site received mixed refuse for the past 15 years The depth of
the excavation where the landfill presently exists was approximately
to bedrock in some places Tne exact depths of landfill material is
unknown
The landfill cover has been graded and sloped generally eastward
to convey surface runoff to the eastern side A sandy soil that was
excavated locally was used as tne cover material The northern
section has a vegetation cover and the recently filled southern
section has been seeded and mulched The six monitoring wells W
NW NE EC SE SC were placed by the town of South Kingstown to
provide water quality information
Referring to Fig 2 the west excavation stream drains the area
created by the excavation to the west of Rose Hill Road and flows
throughout the year The central stream drains a small watershed
area which lies to the northwest of the landfill and drys up during
part of the year These streams flow into the Saugatucket River
which flows throughout the year and is larger than the west and
central streams combined
11
The USGS Groundwater Map (18) was initially consulted to proviae
information on the ground-water flow patterns (Fig 5) and the
geology of tne area (Fig 6) The surficial geology borings and the
vertical geologic cross-section at the base of the study area
indicate shallow water table and bedrocic and a nearly constant
saturated thickness (18) Boring logs at the W well ana a point
approximately 150 feet south of it indicate glacial outwasn material
which is primarily sana with a trace of gravel over bedrock at a
depth of approximately 33 feet Borings at the east landfill area N
and S monitoring wells indicate the same aquifer material
(Appendix B)
The ground-water map developed by Hahn is taken as
representative of conditions existing prior to the excavation of the
I l andfill (18) This indicates water-table contour lines that run in i
a general northeasterly direction This means tnat flow was
originally in a southeasterly direction However contamination of
domestic supply wells on the west side of Rose Hill Road has
occurred (Fig 3) strongly suggesting that the original flow pattern
has been altered by the excavation to the west of Rose Hill Road and
the landfill to the east of it Domestic supply wells were formerly
located directly to the west of Rose Hill Road but were aoandoned
when they became contaminated from landfill leachate New wells
were located to the south and west away from the contaminant plume
of tne landfill In addition a well located at the northeastern
corner of the landfill was contaminated and a replacement located to
the east of Us former location on tne opposite side of the central
12
Legend scale 124000
mdash-40 mdashground-water contour elevation
Fig 5 Ground-Water Map
13
Legend feet
TILL
Fig 6 Geology Background Map
14
stream This second wel 1 also became contaminated Domestic supply
wells located near tne northwestern corner of tne landfill and
approximately 300 feet south of it nave remained uncontaminated
These well locations serve as an indication of tne extent of the
landfill contamination which is largely dependent on the groundwater
flow patterns To furtner investigate this problem and provide
substantial information on which to base the geohydrologic analysis
field studies of the area were conducted
15
Field Studies ana Procedures
A map of the lanafill and an aerial pnotograph of the area were
obtained A tracing of these maps superimposed upon another
delineates stream landfill and monitor well locations (Fig 2)
The field investigation concentrated on the west landfill area ana
its aajoining streams ana monitor wells The east landfill area and
the three monitor wells in that area are induced in the latter
phase of the study in oraer to expand the model area
A traverse which establishea tne monitor well elevations was run
using a Carl Zeiss level These were originally sitea in by the
town of South Kingstown using a local USGS reference datum number 40
(18) The wells of known elevations then served as benchmarks for
referencing adjacent stream elevations This in combination with
the depth to water table measurements at each well enables tne
water-table surface geometry of the area to oe visualized
Water-table measurements of the west landfills wells were recordea
over a ten month period to record fluctuations (Fig 7 Table 1)
The east landfill areas wells were monitored for a five month
period Using a given water-table condition a ground-water map was
developea of the area (Fig 4) This indicates an outflow from
the landfill primarily in a southeasterly direction and partially
in a southwesterly direction
Additional bedrock and water-table information was ootainea by a
seismic refraction survey at several locations along the landfill
perimeter A Bison Model lb70C Signal Enhancement Seismograpn was
used to maxe the surveys Lines were run (to a length of kOO feet)
16
17
w s p bdquo S bdquo s S S a laquolaquo _
s 2 8
V
r bdquo
3 s a
-R s
S
S 3
t
raquobullraquo
S
5
K
r
~
3
K
pound
7
S
bdquo3
C 5 S
shy raquo S s
1 3 s 3 2 5 ^ bull
5 m
s o
^ 3
raquo
--
R bull 5
s pound J O s
5 a 3 7 3 m
5 s a ^
iraquo a s rlaquo
M ^
^ c o 2 5 s 3 a S R
rd 3 y a O =J
^ bdquo
JJ s s 3 bull ~ I
~ s 5 3 a s a
(Ogt (U
2
-t =
r s s in
5 y
a s
5
3
s
5 a
^ a
3 a 51 a bullbull
sj 5 Ml
3 a bull
s raquo
a
0)
0
^ mdash
a j -
-3
C
g S
S
bull a
-
~ 3 o
2 s s 3 a bdquo s s $ Al s
(1) = $ s 3
S
c a a
3 e 5 s N s S a - 3 = s s a 5
a s s - 3 S shy
4
0
a s
bdquo tfH
bdquo
3 a
bdquo
s a
e bullfl s i s s a s a
3 nt
s s 3
g laquo s3 a
~ J s 2 a s o s S s 3 a a j laquo s o s
3 bull laquobull
2 a 7 3 a 3 a ^2
s mdash 5i o
bull bull
mdash
3 o
ss a
fc mdash
3 1-sect m ishy n
18
in both directions to provide a check and permit accurate estimates
of the depth to bedrockThe seismic results allow approximate
interpretations of the depth to the water table and bedrocK thus
permitting an estimation of the saturated thickness Ground
elevations at the location of the seismic surveys were determined
from a topographical map and field siting From this information
water table ana bedrock elevations estimates were made Bedrock
contours are listed in Fig 8 In addition a table which
summarizes the seismic refraction results for the unsaturated
saturated and bedrock layers velocities and depths at each survey
location is presented in Table 2
Scream gauging stations were established on the two streams
bordering the west landfill (Fig 9) Three stations were placed on
the central stream These provide information on the influent or
effluent condition of ground-water flow in the upper sections of the
stream and ground-water baseflow from an area adjacent to the
landfill into the stream (Table 3)
The stream gauging stations used were 90deg V-notch weirs The
weirs located in the SE and SW positions were placed in the
streamoea with a liner of plastic upstream to minimize underflow
The weirs located in the NW and E positions were cut to fit in
recesses of concrete culvert pipes Concrete plywooa interfaces
were coated with roofing cement to minimize bypass flow Upstream
water pressure and a snug fit hold the plywood sections in place
All weirs were implaceo according to AigtTM reouirements and flowrates
calculated using the standard 90deg V-notch formula (3)
19
N
seepage West observat ion Landfill hole
Area
Legend landfill limit excavat ion limit
copyWNWNEECSESC monitoring well locations
= = = unimproved road -- WNES-number
seismic refraction locations
-40shy approximate bedrock contpur elevation
feet
Fig8 Seismte Survey Location
20
c ^-^ c4j ^laquoc in -=r 3shyjj bull pn f- 4-gt bull in in OjJ bull bull a jo bull bull O JJ
co CM o on on CO CM CTNVO VO co CM o on on Q gt_x rH oj on a oj on a - rH oner
rmdash on sr i i
M z Z
gt gt gt
X-N CO laquomdashv CO CO bull igt gt bull
1 gt fc^gtgt bullbull ^ ^ ^
C 4-gt O t igt O J- 4J O H m o o o 3 bullH CO O rH in 3 bullH co vo o in 3 ~ 1 i-k -i ^trade fj rj ui ij o CO o n o rH =r co o n vo vo vo co o bullv O O O
O raquo On-3 rH O -bull- rH ON in _ IH in oj - rH bull rH VO OrH bull rH On ON pH d)u CO -UCO 4J OJ CO 4-gt gt
C mdashbull gt CM gt CM H-l O CO
v- ^^ N C 0
bull0 N CO
4-5 -0 _c^gt in in CO CO
C x~ c -^ t-oo in i 4J j_gt 41 4J bull 9 bull bull 4J bull
o j ON O O 3 (0 O4J O ON ON QJJ t~-^3- OJ 4-gt L
CO CM trade CO CM rH rH OJ co CM oj on Q ^ _ CO 3~Q-- n 45 Q mdash OJ OJ OJ C (0
1 11 3 nZ 2CO
gti gt gt CO CO CO ^-x m -s CO
rH rH ^ ro^^ bull gt bull ^ igt gt bullgt gtgt bull r O -Q 4Ji JJ O 5- JJ O pound- ^ O 4) oj o on (0 CO
3 bullH CJ O O in 3 bullH CO Cmdash VO on 3 pound-laquo H CO o n in inco co o n ma- r co g^ 5sect^ o
o rH on oj O bull- rH ONCO L O_ rH OJ VO M
rH bull rH =t rH bull - OJ T CO CO M CO 4-gt rH CO -U rH CO 4-) s
uits
CO 4-gt 4-5 T3 gt CM gt CM gt CM cc CO CO CO
3 3gt oa tlp^ CO O CM O gt 4J O 40 i 3 r+ k C pound JS
CO pound
^^ s -bullgt cmdash on poundZ VO CTI trx 4J 4J 4J
) bull bull bull Q Q Q Q4J 3shyc O-JJ CTgt OJ OJ Q-IJ inco on CO CO CO o co CM oj on co CM oj on co CM on
Q Q QON^ Q bullH Q^
rH rH 4J rH
O bullraquo L Z bull CO CO CO
i gtgt rH oj on gt tgtshyCM ^ cO^-s CO ~ CO
CO CO J X fc^_ bull^gt bullgtgt bull gt gtgt bull gt CO
j_ jJ O pound- Jj -P O Li deg =fObullH co on f- ^ 3bullH CO CO O in 3bullH CO
g^ -^2
poundsect HO
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3 CO in in in in in in co o n co o n
o -^ r oj in O rHCO CO rH bullrH bull rH =T OrH bull rH OJ f-CO 4J bull- CO 4J rH O0) J-)
gt CM gt CM gt CM 4J
CO N_^ m^
bull OJ
t t poundshyCO CO CO CO rH J3 gt r-t oj on gt r-i oj on gt gt r n o j o n
lto co lto CO T bull ii-4 laquomdash bullmdashH
bullo CO L L 0)
CM CO cc
21
N
545-594
seepage observation
hole West Landfill
0NE I47-509
Area
Weir 45
i487-531
0 EC Al3-467
Legend bullmdash landfill limit -bull---excavation limit r-s stream
copy WNWNEECSESCSEN monitoring well locations
= = = unimproved road
Weir location and elevation
feet
Fig 9 Weir Locations and Wate r Level Ranges
22
JT NO
S shy S
O
bull ry m
oa
NO
(M raquo 1 03 or NO m
JT O O raquo
O NO 03 (j
PW tn in ^4 fraquo
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mdashraquo 3 M
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H fy (NJ
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1 4 03 O
o
o
03 CM
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7 raquo
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i in
i ru
i 0 rsi -or^
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03 raquo
1 O3
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03
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o 03
m oi
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(M
r
(M
CO i M 03
m N ltn ~+ ltM -
QJrH
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8 a
m
^ NO
8 fNl
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bull3 as m o 03 03 4
i O
i ^
shy
O
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ON f tn H 1 4 raquo4 i-4 H P-t
^^ lt-l
r-laquo
^ 1 1 1 1
pound raquoraquo O)t o gtz
bull bull ltbull
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1 pound OJ
3 oi g bull
pound
1 pound laquolt bull
3 bull o a
pound
5 laquo15
f bull 3 Jl s
5bull 1 5
23
A field study to determine the infiltration capacity of a
section of tne landfill topcover was conaucted A modified version
of a double ring infiltrometer was used to study infiltration rates
(4) The cylinder diameters useo in this study were 8 inches and 18
inches A constant head of 6 in was maintained in the
infiltrometer and rates of infiltration were determined Tnese
results and an analysis of surface infiltration into the landfill
are included in tne analysis and discussion section
Specific conductance levels in the monitoring wells in the
streams bordering the landfill and at observation holes near the
landfill were measured (Fig 10) This is a good indication of the
mineralization of water (39) Specific conductances were measured
intermittently over the ten month period to develop a picture of the
extent and degree of contamination in the wells (Fig 11 Taole4j
and in the surface contamination monitoring locations (Fig 11
Table 5) A comparative standardization of the Beckman (short and
long probes) and YSI specific conductances is in Appendix C
A surface electrical sounding using the Schlumberger array was
conducted adjacent to Rose Hill Road at the R-l location (Fig 12)
in an attempt to delineate the vertical extent of the contamination
zone Well W was used as a centerpoint and a reference for
water-table depth pore water conductivity and depth to bedrock A
Schlumberger array electrical resistivity sounding was also
conducted in an uncontaminated area at tne R-2 location (Fig 12) to
provide a comparison background interpretation A seismic
refraction survey N-4 was conducted at the same location (Fig 8J to
24
N
excavat ion
Seepage West observat ion Landfill hole
Area
Stream 1 Seasonal observation 0 EC
hole
East Stream2
Legend sw Weir landfill limit j--1--^ excavation limit
copyWNWNEECSESC monitoring well locations
== unimproved road
feet
Fig 10 Surface Contamination Monitoring Locations
25
8000T
7000
O bull U) W6000
Legend
0 sc A NE O W
A SE O N W
a EC
1 O N D J F M M
Time months Flg11 Flucuatlon In Specific Conductance in Wells
26
Table 4 Specific Conductances in Wells (pmhoscm at 25degC)
West East Landfill Landfill
Date NW NE EG SE W SC N E S
81581 851 938 236 2356
102981 171 3268
11381 3268
111081 304 988 1100 258 3800
111481 426 2736 1216 186 4560
111781 304 3610 433 389 4560
121981 380 1406 129 103 380
1982 160 152
31582 274 760 1064 61 334 8000+ 182 53 84
52182 450 1500 1125 112 712 8000+ 175 255 150
52282 425 1320 1200 110 850 180 320 170
27
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28
excavation
West Landfill
Area
Legend bullmdash landfill limit -bullbull--bullexcavation limit r~~s stream
copy WNWNEECSESCSEN monitoring well locations
= == unimproved road
electrical resistivity sounding
feet Fig12 Electrical Resistivity Sounding Location
L
29
allow estimates of depth to water table and bedrocic to be made
Soundings were carried out to 500 foot electrode spacings to insure
that hredrock was penetrated and to facilitate interpretation These
results and a discussion of the soundings interpretation are
included in the analysis and discussion section Schlumoerger
resistivity soundings were made using a Soiltest R-bO unit
30
Model Development
The USGS Iterative Digital Model for Aauifer Evaluation was
usea to develop steady state flow models of the study area (43) A
flow chart of the computer model and a brief explanation of the
subroutines usea is presented in Appendix D The stream locations
elevations and aauiferlandfil1 geometry and hydraulic properties
were input to the model to compute head values at each 200 foot
grid spacing node (Fig 13) The input data which is for the
existing excavation and landfill conditon is listed in Appendix E
The head values that are computed at each grid space are in turn
loaded into the CalComp plotting routine (44) where a grid spacing
is setup with the computed head values at each node The contouring
program linearly interpolates between these head values and
generates a contour map The computer simulated ground-water
contour map for the excavation and landfill is presented in Fig
14
The streams in the model generally serve as controlling boundary
conditions When using computer simulated geohydrologic models of
an area choosing the boundary conditions for the model that are the
same as prevailing conditions in the field is a critical step in
model development Extending the models boundaries to areas in the
field that have a minimum influx of ground-water across them
simplifies the proolem of calculating fluxes from outside the model
area The eastern boundary is bordered by glacial till which has a
low hydraulic conductivity estimated to be 67 ftday(2) This
contrasts to the high hydraulic conductivity of glacial outwash that
makes up the model area of approximately 107 ftday(3036j
31 N
o 9
bullO O
32
33
The Saugatucket River serves as the controlling boundary on the
east A small drainage area directly to the east of it provides a
minimal influx
Beyond the moaels northern boundary the glacial outwash valley
extends to the base of a till covered h i l l on the western half ana
on the eastern side extends along the Saugatucket stream Due to
the relatively large drainage area that lies upgradient from the
northern boundary a recharge flux eduivalent to 10 inyr over the
drainage area on the till hill and outwash area north of the model
area was input as underflow (Fig Ib) Part of this was input at
each northern boundary node Till has a lower infiltration capacity
than outwash so more of the precipitation w i l l be transmitted as
overland runoff resulting in a lower ground-water baseflow The 10
inyr of recharge that results in a ground-water inflow from the
combined till and outwash region represents an estimate that is
smaller than the 14 inyr recharge for glacial outwash areas in
Rhode Island (25)
The glacial outwash valley extends beyond the western boundary
No significant ground-water recharge flux was estimated at this
boundary A relatively low ground-water gradient exists to the west
of this which does not provide a significant flux across this
boundary Tne southern boundary is basically the outflow region for
the area and therefore would not reauire any ground-water flux into
the moael area across this boundary This boundary was set south of
the point that the streams in the model merge together Therefore
the streams which lie to the north of it are the controlling
34
scale 124000
Fig 15 Northern Drainage Area
35
boundary conditions The flux out of the downgradient outflow
region approximately eauals the influx from precipitation recharge
and boundary influxes
When tne stream configuration in the moael area are reviewed it
can be seen that they comprise a large portion of the boundary
area The screams can act as sources or sinks for water in the
model thus providing to and removing water from the aquifer The
leakance option was used in the model which provides for a confining
bed and aouifer area beneath the stream to be input
The leakance is defined as the hydraulic conductance of the
streambed divided by the streambed thickness which in this case is
taken as 1 foot The leakance value at each streambed node
restricts the flow between the aduifer and the stream The
streambed hydraulic conductivity is typically 01 the value of tne
hydraulic conductivity of the aduifer (717) The value 107
ftday was used for a streambed conductivity based on a value of
107 ftday for the aquifer The aduifer and stream hydraulic
inputoutput exchange at eacn node is calculated by initially
finding the difference between the initial field stream head
elevations and the computed head elevation values at the
corresponding nodes This head value is then multiplied by the
(Leakance value at each node) x (stream area of each node)
Therefore if the aduifer head was lower than the stream head the
stream would act as a source of water for the aquifer and vice
versa
36
Tne leaxance input at each stream node is the ratio of the
actual field streambed area in each node to the area of each node
which is 200 ft x 200 ft = 4 x 104 ft2 The west
excavations stream width is approximately 3 ft central 4 ft and
east 5 ft Therefore if tne west stream traverses the node
directly without meandering it presents a leakance of 3 ft x 200
ft4 x 104 ft = 015 Leakance and streamhead values were
input at each node to set up the stream flow parameters in the
models
A recharge value of 14 inyr over the entire area was input at
each node This represents a value of precipitation that is
transmuted into tne ground-water rather than being directly
evaporated evapotranspired through plants or overland flow
runoff The precipitation recharge flow from the stream into the
aauifer and boundary fluxes provide the model witn input flow
parameters
From analyzing the available information it was determined that
the study area lies within a glacial outwash area with a relatively
shallow bedrock The seismic survey around the landfill generally
indicates a depth to bedrock below the land surface of approximately
29-43 ft with corresponding saturated thicknesses of 19-33 ft as
seen in Table 2 This agrees with borings from tne USGS groundwater
map in the stuuy area (18j The seismic survey was run at a low
water table condition which was several feet below the high water
table level (Fig 9)
37
High water-table saturated thicknesses were used to develop
model parameters For the purpose of this model study the saturated
thickness was set at 30 ft except in the vicinity of well W where
there is a bedrock high (Fig 8) At this location a high water
table saturateo tnicxness of 8 ft was estimated In tne vicinity
the seismic survey was conducted the bedrock elevation at this
location is the highest and the saturated thickness the least Tnis
can be seen by an east-west cross section of tne landfill (Fig 16
The boring log for well W indicates a sand trace gravel outwash
material (Appendix B) Boring logs at the eastern landfill area N
and E indicate similar material On this basis the hydraulic
conductivity was estimated at 107 ftday (3036) Witn the
exception of the landfill and the bedrock hign areas the
transmissivity values were set at 107 ftday x 30 ft = 3210
fto day From the literature the hydraulic conductivity of the
landfill material was estimated at I ftday (19) The
transmissivity of the landfill material in tne nortnern section was
estimatea at 1 ftday x 30 ft = 30 ft^day or approximately two
orders of magnitude lower than the outwash In tne landfills
southern section the original excavation was not as deep as in the
northern parts The landfill material was estimated to makeup only
one half tne saturated depth the remainder being the original
glacial outwash material (Fig 17) Therefore the transmissivity
at the southern end was estimated at 15 ft x 107 ftday + lb ft x
1 ftday = 1620 ft^day These values were graded into the 30
ft^day values at the landfills northern halfway point These
38
were input as transmissivity values to the model at their respective
locations This model did not use the water taole option so
water-table fluctuations did not affect the transmissivities
39
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Model Calibration
A simulation was run using the initial estimates of stream
parameters aquifer and landfill hydraulic conductivities
transmissivities boundary and recharge conditions to approximate
water taole conditions in tne fiela Initially the existing
condition of the excavation area to tne west of Rose Hill Road and
the landfill to tne east were modeled in order to calibrate the
model to current field conditions as shown on Fig 4 The simulated
well values (Fig 14) fall within tne range of field values (Fig
9) The resulting contours also provide an approximate matcn This
can be seen by comparing Fig 4 with Fig 14 An additional check
was to match the flow loss and gain in the streams between tne weirs
in the central stream which w i l l be discussed later The
simulated flow value from the excavation drainage stream is the same
as that measured at the SW weir location Having calibrated the
model by approximately matching well water levels nead contours
and scream flow values different field conditions and possible
remedial measures can be simulated
When the model grid was laid out over the study area as viewed on
Fig 13 the stream configuration rarely traversed the grid nodes near
their central axis When the stream locations were input to the
computer the information was documented as crossing the central axis
of the grid nodes The result of this is a slight aberration when
the actual stream configuration is laid over the computer graphics
head contour output The streams dont always cross the groundshy
water contour at the logical location Rather than modifying the
actual stream configuration to adjust then to the computer output
their actual locations are presented
42
Simulations
i The primary focus of the computer modeling is to analyze flow
patterns under changing conaitions in the near vicinity of tne raquo
landfill The study areas overall flow patterns as they exist
today are first presented in order to realize the lateral east-west
head contour lines between the stream that directly borders the
landfill on the east side and the SaugatucKet stream (Fig 14)
This indicates a general southerly flow direction in that area As
different conditions are modeled these contours generally maintain
their east-west orientation In order to facilitate interpretation
of flow patterns in the near vicinity of the landfill flow patterns
to the west of the stream that borders the east side of the landfill
r are presented in the subseauent models
L- Natural Conditions
The results of modeling the original natural conditions are
shown in Fig 18 The excavation and stream to tne west of Rose
Hill Road and tne landfill did not exist in this simulation The
southwestern boundary consists of a drainage stream that was
delineated using an aerial photograph and stream elevations were set
using the topographical map The USGS ground-water map (18) was
used to estimate head values between the west excavation and north
streams These were input to the model as constant heads on the
models western boundary The resulting simulation generally matches
the southeasterly flow direction that is indicated on the
ground-water map (Fig 5)
A3
Legend
x-^- stream 400 = = = unimproved road
I f ee t
Fig 18 Natural Conditions
44
Excavation Without Landfill
The condition of the excavation to the west of Rose Hill Road
with its resultant drainage stream without the landfill was modeled
next (Fig 19) The extent of the excavation ana the location of
the new drainage stream were delineated using the aerial
photograph The west stream elevations were sited in the field and
used in the model The concept of a confining streamoed layer was
excluded in tne excavation drainage stream under the concept tnat no
significant organic layer had been built up within the 25 year
period that the excavation had been initiated Head values between
the west and north stream boundaries were interpolated and input as
constant head values on the northwestern boundary The west
excavation drainage stream creates a condition that alters the
natural ground-water flow patterns by creating a more southerly flow
condition the drainage stream providing a more immediate surface
outflow in that area
Landfill Without Excavation
The hypothetical case of a landfill without the excavation was
modeled next (Fig 20) The low hydraulic conductivity zone of the
landfill changes the natural flow conditions and creates noticeable
mounding This is evidenced by the decreased spacing of the head
contour lines and deviation from the lateral contour lines of the
natural conditions and higher head values (Fig 21)
45
Legend
excava t i on s t ream
400 unimproved road
f e e t
Fig19 Excavat ion without Landfill
46
Legend
landfill limit
bull - s t ream 400 copy WNWNEECSESC
monitoring well locations f ee t bullbull-bull=bull unimproved road
Fig 20 Landfill without Excavation
1
oin CM
bull
m u
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bullo 9
bullo 9
o rf o o CO 1
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47
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48
Landfill ana Excavation
The condition of tne existing landfill and the excavation with
the dam is the next condition modeled (Fig 22) The ground-water
elevations used to calibrate tne model correspond to an actual high
water table condition Between the NVJ and pound weir a streamflow loss
of approximately 102 gpm occurs aoout 60 percent of this flow is
lost at the dam site which maintains a head of b-6 feet over an area
of approximately 1800 feet^ This approximates a field value of
1144 gpm influent to the aduifer between the NW and E weir on ]2
December 1981 (Table 3) From the E weir to the SE weir a net
increase in flow occurred of 74 gpm which corresponds to field
increase of b62 gpm
The surface runoff from tne landfill flows primarily toward tne
eastern side of the landfill Increases in water-table elevations
on the eastern side after heavy rains such as the 11 November 1981
storm indicates that this runoff increases outflow gradients to the
stream and therefore increases streamflow Surface runoff input is
not modeled which explains in part why field stream inflow values
are slightly higher than model predictions especially for periods
after a storm has occurred The flow from the SW weir located at
the southern end of the excavation represents drainage outflows from
that area The net flow calculated in the model was 140 gpm
which approximates field conditions of 1642 gpm on
December 9 1981
49
d f l f reg N E
shy
Legend
landfill limit -bullgt-bullgt- excavation ^-N_X- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road
-40mdash approximate groundwater contour
400
feet
Fig 22 Landfill and Excavation with Dam
50
The modeled flow patterns suggest how the various contamination
zones around the landfill have developed to their present state
They indicate a flow to both the southeast and southwest on their
respective sides of the groundwater divide Evidence of a
southwesterly contaminant flow is presented when the continued high
specific conductance contaminant level in tne observation seepage
hole is realized (Table 5 ) In addition the specific conductance
increase in the west excavation stream is evidence of an influent
contamination flow
Contamination flow to the eastern and southeastern side of the
landfill is obvious High specific conductance levels in the wells
on the eastern side (Table 4 ) a specific conductance increase
between the E and SE weirs (Table 5 ) and contamination in the NE
domestic supply well (Fig 3) present conclusive evidence of
contamination to the eastern side of the landfill
An anamalous condition that exists is a domestic supply well
located approximately 300 feet due south of the landfill remains
uncontaminated (Fig 3) Flow patterns indicate that contamination
would be transported from the landfill south to this area
(Fig 14) One explanation is that a pocket of clay at the southern
end of the landfill area was discovered in the original excavation
for the landfill (lt6) This evidently prevents leachate from
reaching this wells radius of influence
51
Summer Conaitlon
As described earlier during dry months of the year the stream
that normally borders the northern and eastern side of the lanafill
may dry up as far as a point southeast of the E well Tnis
condition existed from the 15 August 1981 to the 27 October 1981
period when streamflow commenced in the northern part of the stream
yet did not overflow the north dam until 17 November 1981 This
created the present day continuous flow condition throughout the
stream These summer conditions were modeled by removing the stream
above the aforementioned location while other conditions remained
the same (Fig 23) Summer condition well water levels listed in the
model generally match field low water table conditions (Fig 9)
Because there is no stream upgradient from the landfill to provide a
stream head and infiltration through the streambed groundwater
runoff from the area north of the lanafill is the controlling flow
input In these moaels an average recharge of 14 inyr was used
which represents a yearly average The summer recnarge conditions
are prooably lower given the effects of decreased rainfall and
increased evapotranspiration during the summer months A domestic
supply well whicn exists northeast of the landfill (Fig 3) nas a
greater potential to be contaminated from the lanafill at tnis time
than when the stream is flowing Flow patterns from the landfill
are such that during an upper stream no-flow condition groundwater
flow patterns are more in an easterly direction than in a
southeasterly direction The stream would act as a source of
infiltrated water upgradient from tne landfill and provide a
52
I ^N gt i I i j i -r- -bull- bullr -T- t- -r- i- TJ JV
bullbullT laquo ^ O - laquo bdquo xi cshy
H r^~ I -~- --^ X- = mdash x^ N
^--^ A bull O^NW -v - gt-bull Ni i I _____mdash - bull laquo l - mdashmdash 1 deg I ^ltv I C
I reg NE A
Js bull vbull A ~ - v T gt- ^ ix - N
-5Z- | N TfS lV I -bull bull iA i gt gt I ^ bullr-Ky L bull 1 _- copy]wgt-- - bull- mdash - - shy
= r Y ~mdash ltmdashA A
^^-lt A _ - - - - bull Hmdash - reg EC x ^-mdash mdash I ---mdash_mdash -t-V-^N - y
I- -bull - r x i X
V ^ 7 I -v (^~~^^r ^^^
sc Emdash-bull vV JI - - - ~ r )N y- -
X - bull r bulllt
^bull^ y y Jlaquo^ - -lt shy
T s^ lt^ ^ +^-b (
X
Legend
landfill limit j-j-bullraquobull excavat ion gt^ -x- s t ream
reg WNWNEECSESC monitoring well locat ions
= == unimproved road fee t
Fig 23 Summer Condition
400
53
constant head across tne northern section of the landfill This
would tend to orient the flow in a more southerly aowngradient
direction In addition the stream which flows adjacent to the
northeastern well could provide a source of infiltrated clean water
to it which would minimize the possible contamination from landfill
leachate
Without Dam
During tne spring scream flow condition the dam failure which
occurred between the 15 March 1982 ana 9 April 1982 monitoring
periods decreased flow to the aauifer and landfill This eliminated
the 5-6 foot head difference over a 19000 ft^ area which had
created a larger area and elevation head for infiltration to occur
The condition without the dam was modeled by reducing the area
encompassed by the dam to a 4 foot wide stream channel thus
reducing the leakance value at that node (Fig 24) The flow change
from the stream to the aduifer between the NW weir and E weir
reduced the model flow loss to 50 gpm Tnis corresponds to the 9
April 1982 monitoring period which indicates a 30 gpm loss
As compared to the previous flow loss in the upper stream
sections to the aauifer the 21 April 1982 and 22 May 1982
measurements between the NW and E weirs indicate a flow gain The
streamflow conditions have changed from an influent
stream-to-aauifer condition to an effluent aduifer-to-stream
condition that increases flow downstream
54
Legend
landfill limit j--i--i- excava t ion x-gtmdash^- stream 400
copy WNWNEECSESC monitoring well locations
= == unimproved road f e e t
Fig 24 Landfill and Excavation without Dam
55
Analysis and Discussion
In order to fully understand flow patterns and Quantify leachate
outflows at the landfill it is necessary to arrive at an estimate
of flow inputs from precipitation ana upgradient sources In the
following analysis it will be demonstrated that the rainfall input
to the landfill is the factor which controls leachate generation A
calculation using the H inyr recharge over the area of the
landfill was made to estimate the leachate outflow due to rainfall
infiltration An estimated 134 gpm is generated from the entire
landfill area Simulation of the existing conditions (Fig 24)
indicates a groundwater divide in the landfill is located
approximately at the western third Therefore approximately 23 of
the generated leachate flows to the eastern side of the landfill or
9 gpm The effect of the flow input from the upgradient stream is
evident when tne summer condition witnout the stream is viewed
(Fig 23) Without the stream to infiltrate the landfill and the
recharge and northern boundary condition as the flow inputs the
head at the northern end of the landfill drops about 5 feet from its
previous value A flow pattern from the north central part of the
landfill to the eastern side indicates a 12 feet head difference
with recharge - but with the upgradient stream a 16 foot head
difference occurs Considering the transmissivity change the
stream would increase the leacnate outflow from the landfill
approximately 43 under a low water table stream influent condition
to the aauifer This would increase leachate outflow to the east
side to approximately 129 gpm This value approximates the
56
outflow at the SE weir location during the summer monitoring period
when the upper stream was not flowing (Table 3) The outflow from
the western third of the landfill whicn lies to the west of the
ground-water divide would be approximately 63 gpm
Realizing the importance of infiltration to tne landfill as a
major influence on the generation of leachate an analysis of this
w i ll be discussed An estimate of infiltration was made using the
precipitation recora for October ana November (Appendix A) During
this time period a minimum of direct evaporation ana
evapotranspiration occured and the grouna is not yet frozen The
top cover over the lanafill is generally 05 ft to 2 ft of local
sandy soil and subsoil availability determined what was used The
top of the landfill is at an elevation of 92 ft as compared to the
ground surface at well W which is at an elevation of 76 ft
(Fig 25) This compares to the well W water level which is at an
elevation of approximately 52 ft This creates a long path for
infiltration through the unsaturated zone The topcover generally
slopes eastwara at a grade of 2-5 The west side maintains a
relatively steep slope of 10-15 ft drop within 50 ft ana the north
and eastern slopes have a more gentle slope of approximately 10 ft
within 100 ft distance An unlined surface arainage swale channels
surface runoff from the northern section of the landfill past the
NE well to the eastern side ana low area in the vicinity of the E
well This has a drainage swale to an area near the stream but
doesnt directly connect to tne stream A poorly graaed drainage
swale exists on the landfills left side The landfill material has
57
excavation
seepage observation ^
hole
Legend bullmdash landfill limit -^--excavation limit r^s- stream
copy WNWNEECSeSCSEN monitoring well locations
--- unimproved road O location of amp Inf i l t rometers O
feet
Fig 25 Infi ltrometer Locat ion and Drainage Feature
58
been placed in 10-12 ft cells and covered with 1 ft of soil at the
end of each day The material has settled differentially creating
areas for depression storage
An estimate of the percentage of precipitation that infiltrates
the landfill was made from precipitation records recorded well
elevations and an estimated specific yield for the landfill
material The volume of water that infiltrated should eaual tne
specific yield multiplied by the well water level rise Several
recharge periods were studied using this relationship Once the
percentage of precipitation that has infiltrated is determined the
percentage that is translated into runoff is simply the remaining
percentage if evaporation is neglected
From the literature for a slightly inclined slope of 2-5
typical runoff coefficients range from 10-20 in either sandy or
heavy soil (16) The landfill cover is generally sloping to the
east which creates a long path (approximately 400 ft) before the
runoff reaches the steeper slope on the eastern side of the landfill
of 15-20 The long drainage distance creates a greater time for
rainfall to infiltrate Another consideration is the actual
capacity of the soil to conauct water into the soil which was tested
in the field using double ring infiltrometers An average initial
percolation of 8 mmhr the first hour and a subseauent rate of b
mmhr occurred (Fig 26) The 8 mmhr rate compares well with
other sandy soil infiltration rates (14) Therefore if the
intensity of the rainfall exceeded a 5 mmhr rate for several hours
59
CO + 09 o
E o
CO
o Z pound C
O
C9
o DC
CO
CD CM
ogt CO N- to -4 CO CM
jq tuu i U O | raquo B J J | | J U |
60
on a poorly drained surface the additional rainfall would be
translated into runoff because the soils infiltration capacity had
been exceeded
The initial 8 mmhr infiltration rate was due to the pore spaces
in the sandy soil being filled and the subsequent 5 mmhr rate was
percolation into the low permeability landfill material The tests
were conducted in November assuming a minimal evapotranspiration
and the field capacity of the sandy soil had been maintainea
The W well was used as representative of the water elevation
changes in the landfill because it is directly adjacent to the
landfill 900 ft distant from the upgradient stream This minimizes
the effect of infiltration from the stream and maintains a high
contaminant level During periods of high runoff conditions excess
surface water ponded in a poorly graded drainage swale on the west
side and directly adjacent to the landfill This influenced the W
well at a time the contamination level dropped (Fig 11) Before
this occurence in mid-December the rise of the W well closely
matches that of the SC well and a background well SK6 which is
located outside the study area (Fig 7) Therefore it was analyzed
as a valia indication of the water level rise during the mid-October
to mid-December period The monitoring of the SC well was
intermittent due to inaccessaoility because of 10 ft extensions
being placed on the well as the refuse was being filled in arouna it
61
A high rainfall period from 14 November 1981 to 1 December 1981
was chosen for the initial study period The effects of
evapotranspiration were neglected due to the cool temperatures
experienced at this time Therefore it was assumed that the field
capacity haa been reachea and tnat any additional input to tne
unsaturated zone would result in direct percolation to tne saturated
zone During the time period 14 November 1981 to 22 November 1981
029 ft of rainfall fell and the well W rose from 488 ft to 493
ft - a 05 ft increase During the next 8 day period there was no
precipitation yet the W well continued to rise to 4972 - a 042 ft
increase The slow percolation of water through the landfill
material would account for the latent rise in the well water level
From previous reports a specific yield for refuse was estimated to
be 028 (1920) This value is dependent on the original compaction
of tne material age and resulting consolidation
During the 14 November 1981 to 1 December 1981 period 029 ft
of rain fell and the well increased 092 ft The following
relationship is used to evaluate the infiltration value and runoff
I = (Sy) h
Sy = specific yield
h = well rise
I = volume infiltrated
I = (028) (092 ft) = 0261 ft
62
The difference between the precipitation and the infiltration is
the runoff (assuming no evapotranspiration) Therefore 029 - 026 =
003 and furthermore 003029 - 13 runoff This corresponds in
the literature to a typical runoff coefficient for an inclined
surface of 2-5
Analyzing a longer precipitation period from 18 October 1981 to
1 December 1981 a net precipitation of 043 ft (accounts for
evaporation) occurred less 10 for runoff or 039 ft infiltrated
This results in a 139 ft elevation increase The well water level
actually increased 132 ft shy only a 5 deviation from the
calculated
From tnis investigation it is seen that a large proportion of
the precipitation has the potential to be transmitted into the
landfills saturated zone Exceptions are wnen heavy precipitation
periods exceed the soil percolation capacity frozen ground prevents
infiltration and direct evaporation and evapotranspiration recycles
the ponded surface water and infiltrated soil moisture back to the
atmosphere In retrospect water temperatures within the monitoring
wells could have been measured to indicate thermal effects from the
landfill on ground-water temperature Ground-water temperatures
were assumed to be 50deg F (9)
63
Specific conductance measurements serve as an indication of
contamination levels These measurements are used to trace leachate
movement which represents ground-water flow patterns Factors which
must be considered when monitoring pollutants are the attenuation of
the leachate contaminants which occurs both in the zone of aeration
and the saturated zone The former is a more complete process
Dilution dispersion and cation exchange are the primary factors
involved in decreasing leachate concentration in the saturated
zone The glacial outwash materials of southern Rhode Island do not
have a cation exchange capacity or a high buffering capacity so
attenuation is simply by dilution and dispersion (22)
The NW well consistently exhibits relatively low specific
conductance levels even though it is in landfill material It is
situated in a drainage swale and ground water elevations range from
543 to 5944 This is several feet below the upgradient stream
elevation of 64 feet which is less than 400 feet away The bottom
of the wellpoint is at an elevation of 5312 feet well into the
landfill material Infiltration from the stream to the landfill has
occurred at this location
The W well is situated on a bedrock high adjacent to the
landfill approximately 900 feet from the upgradient stream and its
water level is higher in elevation than the excavated pit (West
Observation Hole) which is 300 feet directly west The W well
maintains a contaminated level A poorly graded drainage swale to
the west of the landfill provides areas for extensive ponding and
infiltration to occur which explains the drop in conductance after
a high runoff period
64
The SC well is located in landfill material and has a
conductance of over 8000 umhos This indicates that leachate is
undiluted The oottom of the wellpoint is at an elevation of 389
feet which is situated in the landfill material
High specific conductance measurements in the west observation
hole and well W and their relative elevations indicate a
west-southwesterly flow direction from the landfill Infiltration
recharge and leakance from the stream into the landfill provides the
necessary elevation to cause outflow in this direction
Contamination from the landfill to the surrounding streams is
evident (Table 4) During the period 15 August 1981 to 27 Octooer
1981 there was no flow in the stream that Borders the northern and
eastern side of the landfill until a point just south of the E well
was reached High specific conductance levels in the EC and NE
wells were recorded (1000 jjmnos) At a point directly east of well
EC a pool of water existed that was relatively uncontaminated which
is designated as the East Stream] location (Fig 10) At a point
just south of that (East Stream^ polluted water in the streambed
was flowing at a low rate This was measured at the SE weir
location and which had a high conductance also Flowrates varied
between 6 and 23 gpm and specific conductances were over 350
pmhos This low water table condition flowrate is the baseflow from
the eastern side of the landfill and indicates a southeasterly flow
direction from it
Streamflow commenced in tne northern part of the stream 21
October 1931 and the north dam oegan to f i l l Stream specific
65
conductances were low indicating a clean water source Tnis
continued until 17 November 1981 when the dam overflowed ana flow
throughout the east stream began A weir was placed at the Rose
Hill Road NW location and was compared to flowrates at the SE
location Flowrates decreased and specific conductances increased
between these two locations
To further investigate the condition of a lower flowrate
downstream than upstream an intermediate weir was placed at the E
weir location (Fig 9) This snowed tnat the stream from the M
weir to the E weir was losing water to the aauifer (influent
condition) and gaining water at the SE weir (effluent condition)
The condition of a net loss of water between the NW and SE weirs
remained until 19 December 1981 when a snowmelt rain condition
caused increased surface runoff and a net increase in flow at the SE
location Upon analyzing the March and April 1982 streamflow
conditions the expected case of a net ground-water pickup from the
E to SE weir continued The explanation for tne initial net loss of
ground-water is the fact that the leakance from the upstream section
was being discharged into aauifer storage to raise the ground-water
table to an eduilibrium level Upon reaching a high recharge
equilibrium steady state condition any additional input will
eventually be transmitted as baseflow out of the landfill and a
downstream net pickup will occur A hign water table condition
prevailed during the January through May period maintaining this
condition In April the north dam broke through reducing the head
in that area by 4-6 feet The 9 April 1982 monitoring revealed that
66
an influent condition remained between the NW and E weirs but at a
reduced rate The 21 April lower stream flow condition shows a
small pickup of water between the NW and E weirs indicating the nigh
water table and low stream flow conaitions combined with the absence
of the dam had changed the conditions to an effluent condition
This was evident in the May monitoring period
Evidence of contamination on both the western and eastern sides
of the landfill supports the existence of a ground-water divide in
the landfill The west stream which drains the excavated area to
the west of Rose Hill Road shows contamination pickup between its
northern section and the SW weir The W well and ooservation hole
indicate high contamination levels which reinforces the concept of a
contaminant outflow to tne west excavation stream
As shown previously flow towara the eastern side of the
landfill is evident from the nign specific conductances and specific
conductances increases in the stream This is especially evident
during low flow conditions when the stream starts at a point to the
east of the landfill and flows with high specific conductance levels
From the literature a relationship between specific conductance
and dissolved solids exists the dissolved solids (mg1) are
approximately equal to the specific conductance times a factor
ranging between 55 and 09 (39) in this case it is taken as
065 (41) The dissolved solids increase coupled with the stream
flow increases provides a basis of calculating the dissolved solids
outflow to tne stream This calculation method was used in a
previous study (26)
67
The relationship
=Cinout Coutflow Qoutflow - Cupstream Qupstream Qinput
where the numerator is the streamflow pickup and the C- and
Q-jnput is the concentration and flow input from the ground-water
This can be used to estimate dilution level outflows from the
landfill Initially this is used for the ambient ground-water
pickup between the E weir and the SE weir This entire flow doesnt
come from tne lanafill but much of it is conaucted in the high
transmissivity area between the lanafill and stream from upstream
leaxage ana surficial recharge Tnis is evident when this section
of the flow pattern is analyzed on Fig 22 Therefore the landfill
outflow is mixed with tne ambient groundwater flow which dilutes the
landfill leachate before it enters the stream To illustrate-this
concept a calculation using the 9 December 1981 monitoring is used
At this time a flow of 672 gpm occurred at the SE weir with a
specific conductance increase of 7 ymhos between the E and SE
weirs The dissolved solids increase would be approximately 795
Today in tne stream
Where
Co = 90 jumho at SE weir
Qo = 672 gpm at SE weir
Cus = 83 jumho at E weir
Qus = 606 gpm at E weir
Qinput = 66 gpm gain
Cinput = 154 jumho
68
The 154 jumho value represents the contaminant level in the
ground-water adjacent to the landfill
This relationship is applied to approximate the concentration
level dilution in the ambient ground-water between the landfill and
stream The aforementioned relationsnip is in turn applied to the
landfill outflow into the ambient ground-water flow adjacent to the
landfill The ground-water receives landfill leachate dilutes it
and then transmits it to the stream The previously calculated
value of 129 gpm was used as the outflow from the landfill
Co 154 jumho flows into stream
Qo = 67 gpm flow into stream
Cus = 83 jumho background level
Qus = 67 gpm - 129 gpm = 541 gpm
Qinput = 129 gpm from landfill
Cinput = 451 jumhos
Approximately tne same contaminant levels from the landfill (tbl
umho) are arrived at as existed in the summer streamflow conditions
when the upgradient ground-water flow adjacent to the landfill was
at a minimum
In addition to using specific conductance to define
contamination zones electrical resistivity can be used to indicate
contaminated areas The measured earth resistivity is inversely
proportional to the conductivity of ground-water Water containing
contaminants with high ionic concentrations are more electrically
conductive and will have lower resistivity values than surrounding
natural ground water Therefore resistivity methods can be used to
69
delineate plumes of contaminated ground-water that have hign
specific conductances This has been demonstrated by several
investigations (11122328374045)
In this study a Schlumberger vertical electrical sounding R-l
was made in an area of known contamination at the W well (Fig 12)
Given the geologic constraints provided by the well boring log a 4
layer computer model was used to match field survey values A
Schlumberger sounding R-2 in an uncontaminated area north of the
landfill in the same geologic setting was used to provide a
comparison background sounding (Fig 12) A seismic survey N-4 was
made to obtain water table depth and depth to bedrock as input
parameters to a four layer resistivity model (Fig 8) Tne results
of the electrical soundings have been tabulated in Table 6 and
plotted in Fig 27 and 28 respectively
The ascending portion of the field Schlumberger curves were
initially matched using a two-layer ascending type master curve to
provide an approximate depth and apparent resistivity of the
overburdened topsoil layer (8) Tne second unsaturated layers
apparent resistivity was determined by using the graphical
interpretation of total transverse resistance The total transverse
resistance is approximately eoual to the peak value of the curve
times the corresponding Ab2 distance it occurred at This in turn
is eaual to the sum of the first two layers apparent resistivity
times their corresponding layer depths
70
bullH
OJ bull bullH 4J CO CM
c ce G bullrH
j-gt ca c c a 3 ltu O L
co CO 0
bullo Q bull laquos c n 3 -U OrH f~ 3 bO ltn y CO O cc CO ^mdashN
QQ bull
bO bOJJ C C Ci_i
O l T i O O O O O O O O O O O O O O O O bullH bullH mdash^ bullo 0 C c3 f| 3 O raquo O CO CQ
CO
rH
CO O
L 4J
^ltU
i- 1 ^n ^b O 4-) bull2 CM bullH C OJ 1 -U bullH CO C L O a ^-^ 0) a
rH c a L CD ltu (1) 3 tlt bO cO I
3 a 0) a Q 4J laquoa e CO 3 (H bO c C O bullH
CO TJ C 3 bull
bull O bO -i-3
0 CO C O3- O G O O O O O O O O O O O O O O O O O O ft rt1 -raquo - t l S^ ft tfigt f I mdash^ K_ l_ raquo mdash I gt fgt I l 1
(1) 0 rH CO CJ JD o^^ CO CO CQH lts
71
Legend
A actual field measurement
-e- interpretat ion
10000 bull
6000 bull 5000
4000-
3000shy
pound2000| ltD
_ r 1000
09
5 600 pound 500 - 400
I 300 a a lt 200
100 10
Fig 27
20 30 4050 100
Distance AB2
Schlumberger Sounding
200
feet
R-1
400 600
72
loooot
6000 5000 4000
3000+
laquo2000 e
r 1000
raquo 600 pound 600 ~ 400
$ 300 a a lt 200
100
Legend
A actual field measurement
-Qmdashinterpretation
10 20 30 40 50 100 200 400 600 Distance AB2 feet
Fig 28 Schlumberger Sounding R-2
73
Formula T = f
Background Sounding (9000)(15) = (3110j (1 7) + gt2(8)
= 16214 n- ft
W Wel l Sounding (b200)(60) = (500) (2) + pound2(28)
= 13250 SL- ft
To determine a resistivityp3 value for the third layer a
graphical interpretation for the longitudinal conductance S was
used(48) This is eaual to the sum of each individual layers depth
divided by their apparent resistivity
Formula S = -r1 +~r-raquobull-ra
Background Sounding 0017 = yyg + ~^
= IbOU - ft
W Well Sounding 0285 raquo -ggg 7^3 J~
= 179 v-ft
These values were input to a program which calculates a
schlumberger sounding curve (47) The theoretical sounding curves
approximately match the field curve as viewed on fig 27 and fig
28 To provide a check on the apparent resistivity of the saturated
layer at the W well the following relationship was applied 1OOOO
= spec-jfic conductance (umhos)
74
At the W well the specific conductance was measured to be 3 00
jmhos at approximately 10degC
Assuming a formation factor of 45 for the glacial outwash (23)
material Archies law is applied to estimate an apparent resistivity
of the third layer (7)
fgt FF x p
A= 45 x 103-n-ft
A= 4G3 JL-ft
This is a reasonable approximation to tne 3i= 179^-ft calculated
analytically from the sounding curve interpretation
75
Remedial Measures
With the analysis of f low patterns and contamination zones
recommendations to minimize the environmental impact of the leachate
can be reviewed The basic technique is to minimize all sources of
water reaching the refuse so that leacnate production is minimized
The oiversion of precipitation by a relatively impermeable cover and
proper channeling of runoff would minimize percolation into landfill
material Caps and seals can be constructed of clays fly ash
soils soil-cement lime stabilized soil memorane liners
bituminous concrete and asphalttar materials (15) Proper
contouring and grading will help minimize infiltration If a soil
cover is used a vegetative cover can be planted which will utilize
some of the infiltrating flow through evapotranspiration losses
during the growing season By minimizing the length of slopes and
providing proper drainage channels tne surface runoff can be
conveyed to a downgradient area outside the recharge zone
Therefore this surface water will not increase leachate production
from the landfill Also by increasing the slope of the cover over
the landfill itself a higher percentage of runoff and lower
infiltration will occur
To minimize upgradient ground-water influx to the landfill an
impermeable subsurface barrier or intercepting trench could be
used Barriers can be made of bentonite slurry-trench cutoff walls
grout curtains or sheet piling cutoff wal ls extending to the bedrocic
or an impervious layer to effectively prevent water passage or
create a head loss that wil l lower the water table In addition an
76
intercepting trench which has a perforated drain at tne lowest part
of the water seepage zone could be used to intercept and divert the
entire flow
These possibilities have been evaluated with the help of the
model to determine workable solutions for this landfill The
primary concern is to eliminate leachate flows to domestic wells
Initially a simulation was run that eliminated recharge over tne
landfill area (Fig 29) This had a considerable effect on the
ground-water flow patterns of the landfill area The mounding that
had previously occurred under normal recharge conditions was
eliminated and a general drop in the water taole within the landfill
of 2-3 ft occurred The effect of eliminating recnarge over the
landfill when the upper stream is running would cause greater
infiltration from the stream as evidenced by only a 2 ft head loss
in the landfills flow conditions This is evident when comparing
Fig 29 with Fig 24 Tnis indicates that this measure would only
marginally reduce the resultant leachate flow from the landfill
material that lies below the water table In another situation
where there is not such a strong potential for upgradient flow this
measure has proven quite effective (6) In this case the landfill
cover consisted of four layers an intermediate sand and gravel
cover immediately above tne regraded waste materials a 4 inch sana
bed designed to protect the overlying membrane a ilO mil flexible
PVC membrane and an 18 inch final cover of sand and gravel
77
Legend
landfill limit -raquo- -^ -raquobull excava t ion x-^x- s t ream
400 copy WNWNEECSESC monitoring well locations
= -= unimproved road fee t
Fig 29 No Recharge over Landfill
78
Controls such as 10-30 mil polyvinyl chloride covers favor the
development of an anaerobic environment which increases waste
decomposition time and would necessitate installation of gas vents
at several locations on the landfill cover Tne integrity of tne
synthetic cap may be further threatened by subsidence which create
differential stresses on liners Settlement would create areas for
ponding and depression storage and eventually necessitate regrading
the landfill surface The landfills south-central area has oeen
filled within the last year and will prooably need to be regraded
due to settlement within the next few years
Another possibility for a liner would be a soil-bentonite
cover A layered cover consisting of natural materials with low
permeabilities such as bentonite clay followed by a layer of highly
permeable material such as sand and finally a layer of topsoil can
be used Due to potential drying out and cracking of the clay liner
a synthetic liner is the preferred method
The most immediate technique is to grade contour and vegetate
the landfill cover which has been done at this site Althougn an
impermeable cover would probaoly reduce the amount of leachate
produced it would not eliminate the upgradient flow and provide
guaranteed protection of wells in the vicinity of the landfills
northwestern section
A slurry trench along the northwestern perimeter of the landfill
would effectively cutoff upgradient infiltration and divert recharge
infiltration in a southeasterly direction thus removing possible
leachate outflows from the radius of influence of the neighooring
79
wells This has been simulated using the computer moael ana flow
patterns as shown in Fig 30 Contour lines are distorted in the
vicinity of the slurry trench due to the 200 ft nodal spacing
Transmissivity values of 1 ftday were input at the slurry
locations to simulate an impermeable barrier Tne surface recharge
at those nodes does not infiltrate the relatively impermeable grid
nodes at the slurry locations and flows to the edge of the noae
thus creating a dramatic head loss within a short spacing To
effectively simulate this a variable grid spacing should be used
with reduced node grid spacing at trench locations to eliminate
distortion The computer simulation shows that the slurry trench
could direct flow in the landfill area in a southeasterly direction
and away from endangered wells In addition it would reduce
upgradient infiltration from the stream into the landfill This
measure would prevent leachate from spreading beyond this carrier to
possibly contaminate neighboring wells
The combination of both the slurry wall and impermeable cover
would be ideal measures to minimize generation of leachate and to
stop its spread to neighboring wells The slurry wall without
recharge over it or the landfill is simulated in Fig 31 This
indicates a lower water table tnan eliminating the recharge to the
landfill The slurry wall has blocked upgradient ground-water flow
at its location to the landfill
80
Legend
landfill limit -laquo- j -laquobull excava t ion ^^- stream
copy WNWNEECSESC monitoring well locations
= = = unimproved road ssi slurry wall
f e e t
Fig 30 Slurry Wall
81
Legend
landfill limit j- j- J- excavat ion x-v^gt- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road s==s slurry wall
400
feet
Fig 31 Slurry Wall without Recharge Over It or Landfill
82
An intercepting drainage trench is considered next If a trench
was excavated to a 30 ft depth in the outwash material extensive
shoring would be required In addition difficulties would arise
when the trench was excavated below the waterline Tne trench would
be sloped to provide drainage and backfilled with a highly pervious
material to intercept and divert leacnate locally a conouit which
is perforated on the top to allow infiltration and unperforated on
its lower perimeter to permit continuous drainage to the collection
treatment center would be installed on the bottom of the graded
trench The difficulties involved in excavating below the water
table ano shoring the sidewalls to permit implacement of a drainage
conduit at a 30 foot depth make this option increasingly infeasible
83
Conclusions and Recommendations
The location of the South Kingstown landfill in permeable sand
and gravel glacial outwash material (107 ftday) combined with the
high hydraulic gradient across the landfill area (20 ft1600 ft)
creates a high potential for ground-water contamination to occur
This is intensified because refuse nas been placed below the water
table The low hydraulic conductivity of the compacted refuse (1
ftday) and the excavated area to the west of Rose Hill Road have
both contributed to modifying the original southeasterly flow
pattern These modifications have created a ground-water divide in
the landfill at approximately the western third section Tnis
results in approximately 13 of the leachate flow from the landfill
or 63 gpm flowing in a southwesterly direction and 23 or 129
gpm flows in a southeasterly direction Infiltration from
precipitation recnarge over the landfill (up to 9Upound) and from tne
upgradient stream during low water-table periods provides tne
necessary influx into the landfill Evidence of contamination is
clearly seen on both the east and west sides of the landfill which
reinforces the previously stated flow patterns
Of the several remedial measures reviewed the contouring and
grading of the landfill topcover and drainage swale provides the
most immediate protection The topcover has been graded mulched
and seeded to provide a low runoff slope generally to the east
The drainage swale on the left side of the landfill has improperly
graded sections which should be corrected Its northern section
could be drained into the northern sections swale and the southern
84
section drained to the southeastern section of the landfill Tne
point of the drainage swale which divides the northern drainage
swale from the southern one should be determined by a field survey
Cost is a major contributing factor when determining which
remedial measure is to be applied to the given situation For the
purpose of this report cost estimates are not presented but rather
the effectiveness and feasibility of the remedial measures are tne
primary considerations As was reviewed and simulated in the
computer models the slurry trench and impermeable cover over the
landfill are two viable options that would effectively provide
protection to the domestic supply wells in tne vicinity The
impermeable cover would eliminate precipitation recharge into tne
landfill yet drop the water table only a few feet due to upgradient
infiltration from the stream This would decrease the hydraulic
gradient thus diminishing the potential for a contaminant outflow to
surrounding wells The supply well of primary concern is one to the
west of Rose Hi l l Road marked well D on Fig 2 If contamination
occurs in this well the most effective measure would be to block
off leachate flow in this direction by installing a bentonite slurry
trench at the location indicated previously This would effectively
prevent leachate flow in the westerly direction and diverts it to a
more southeasterly direction In addition the slurry trench
precludes infiltration flow into the landfill from the upgradient
stream
85
Tnis report has effectively reviewed tne original ana existing
flow conditions and contaminant levels in the vicinity of the Rose
Hill landfill The purpose was to provide an understanding of
ground-water contamination patterns and study possiole remedial
measures
86lt
Appendix A
Precipitation Records
Monthly normal precipitation 1941 -197O
i$l Total monthly precipitation
KINGSTON RI
14
ia
^JO T I bullbullL
pound 111 laquobull
4
a
n
-
^
-
-
KS1JAN
^Ii R3 HB MAR
1
1 APR MAY
1
1 JUN
1981
JUL
-bullraquolaquo H
AUO SEP
K3~~f$s bull
_imdash
i1S 1
OCf NOV OtC
171 1 iI1
JAN HB MAR APR MAY
198
Fig 32 Precipitation Record
- - - -
IM 1 MtvJrflgtlgt c ortli-A t lUN I r nraquo rl - -
gt|MO CLIMATOLOQICAL OUSERV ATIONshyr-r bull JK gt raquo - 1
i5fWA I VAPOR Al IOH -bull AIM If MPCRATUM bullF 0 riccipn AT ION UNO IlMf
bull 14 H 14 H mdash Vshy ADDITIONAL DATA IfUAlUS OATt 1 bull raquof bull bull 1 ta
14 Hw rlaquo4 w bullbull bull 1 114 1mdash4 (llrl 1 1 1fl Hll
0 kmdash
Mraquo M4 raquo i T i 4 bullraquo-laquobull i i
Lgt f 1 21 S 1 Hbull - - bullbull -
ltJL 1 2 01 - - _ _ 1
mdash
-
1 12 _ Q I
mdash shy
mdash 4 (C ( - - fVi 1 - 0
1 (1
^ 1
Vvraquolaquo IJ1^ raquo CP O 3L 1 Z - i bull j-t-J
1 J
LH Vb T n 0
1 gt fl oo O ~l 2 L - bull 1 P )laquo jn iP IP - OOI L5L mdash shy
-t 84 ^(^^ ^fi P i flja 0 JO II 10 tl tcgt 7 J IV wllaquo
h l2L bull 0 lt -_ shy
-id VJ lt 3C 2 ft OOL -mdash
U 71 C1 Sr 2 13 2 nl JLJraquopound HP r M ltf1- (
IMe 2 ii O It
n jlt dl 1 1 bull o o-il ST i 1 i 25 2-x-1
-
ri
i tlL O mdash gtbull bullgtlt 1ft -o- is Oil So iJK 2-io otv u 31 fil loi 2 il Oll it Of wr is i1raquo -iZ 1 deg|0 01
M IT So - mdash
- 13 1 CT mdash i - mdash 21
shy
Tl Ci av ZUll IMT 0 IM Pe v _ 1) T) S) ii3( dlt Ii 2 lt^2 II li- S1 riivi To 7HX lt3lO 14 ^2- iTi I li 011 -- - -i -^IS no 5^ or i | T Jift laquoV OoH bullla It Va iCO mdash L OIL 11 bullvf poundgtpound lS_ flv oh P-lfe 1 poif _ shy11 IB kl (4 itlaquoT lamp llt0 oot^
mdash -n
It T1 |ir( L1 HI 2 0 oil
U 1M ft go C ICf^ -^2 Z laquo-|o
11 it 5 bulln - TO o abull Li u-i IT1 -- Iw O ltM (I bullbull bdquo-I(K 1mdash -tilltLlA ttfe
i Dgt ac -- U 44 4 11 1 1- ytd i i_i J-K 0 i if -i i i V t Wl raquoOHM 1-1 US D C P A R T M f N T OF COMMfRCE t 4 1 IUII 1 1 ^~) mdash
llaquo- Hi NC bull bullh bull bullJL^V HBl CO 00
11
)jLsVyr^gturv
^ | TKu
|-_t_ bull(
IIMgt I I Mt|UU III- II 11
PNECIPITATIOH
I 1 1 IMX
IMO
bull llfclaquo I UCIUKI) Ur C V A r U M A AHO CLIMATOUOCICAL OBitH
E V A F O R A T I C r i Jttffl laquo amp hMIlaquoJllaquoJIIlaquoBgt
DATE AOOITIOMAL DAIAKMAKk M
bullraquobullmdashlaquo
tp 01 (1 Of Ll OOI ooo
0^1 o-i 10 tl |00 102
OC (1 13 Ofl
it i rc DS os an
(1 SV o
Ul 010
(ISl 101 I on
130
II 5= Otl
ss lt 001 (IK Ml
jt il HIT
7 it
ow Wo 17 Top 2-01 OIO
(0 oov zi oot
u CO ^A 0 to Zoi CLflS
bull50 01 ljtj
nshy 5H LO OIt
50121 IVO QJO
14 Co Ho LO Hl ^pound Jl 1
ltM ool fllc
H Tl 01 II
11 11 Q1
iH OIO
HO 2 llaquol 11 II
lifc
IV-IIM ul OIPAITHINT or COHMIICC NOAA
NAtlOHAL gtIATnlaquoll raquotraquoVlClaquo CD
r~
All TCUMMATUNI ^V UII rgt ITmi 1 Cwphu Obic i gtn t ngir-H 30
rilCiriTATIOH
JJ T I rTJ-rimdashr-iramj|MP CLmATOLOQ
laquolaquo jftilCiii bullIHO
Oi1l ADOITIOHAL DAIAlllu
Ilf4ft
Sii1
(1 2 IO OO
Hl ii SO
us OIM
Q^L
a A3 Hi SZ Sf^ bull 12J2
HI Z-SF OOl 1C t HM IA H ICP fiJA
OOl 10 (310 sn 310
if HI (0 ^01
bullit SO 28H poundJ1 11 006
14 35 TX oon II (bull2 it zr II c-S
rr Zll lo 31 OP an 31 a 31 oor
CSW O-ll Si CC Of 011
Oll _ I |ft
00
u i oerraquolaquoTMiMr of c NOAA
NATIONAL K C A T N C M SCMVlCC
TC^S lk)oiVroTJA
TETT I 7X
1raquolaquolaquo 4 bdquo ir lt er ni I^OV ltqgl j--^ TQ
MICiriTAllOH ITIND
D|mdash
b5NO ctiUATOtoiCAL oeit^
OATI AOOITIOMAL OATAVlHAtt
0-tt
Mlaquoh bullbullbull- rshy laquo
I- ltltriu HI I 4 bulllaquobullbull1
Zii
30 Dfellt otvt
at HA
OOI
62
iJ_S2 HI if
bull- 20 SI 2i So
So
VVfr
OSfc
I (
Jtlt
3aoi
r j -bull ie MA
Irill iiol
in^ 14
Mo
Zll
214
21 1P
00-i
bulliron
17
bullr
11 i ir- I J Ktf^c
US D E P A R T M E N T OF COuMEDCC I | C gt A A
K AIlaquo Ttupf lATuit r
|SlVi AlJ PIICIPITATION
oJud (El
VIM i Uraquo
MIND E
EVAPORATIOH flnrft bull A ftufiifccdll
KECORO OF eVAPllHAtlil bull I CLIHATOLOOCAL OBSERVA ^Hij
14 MM A_M AOOIIIONAL DATA11 MAIM
Mr bullH Oo|
M Si lift
bull221 IHI
ZS Ji 40 IZV
icr KS I
HZ 111
bullT 21
loA UK JA IP
v^ ft
1M 2Sshy IT Tl
71 V |
i I 31 1deg a
uty^ U bull3
ons 1 CiO TxX
HHO (10
3H 19 12 10 IP
raquo3H raquo | 5t io
OP OIT
14
vO UI Of PANTMINI Or COMMCRCf MM O A A
F ngt TIHH
iiicffwiffc 4 rJ (TIM bull Cempltit Obitittiio
AIlaquo TIMHIATUM PHICinTATION I V A f OK ATlPrl
OATI ADDITIONAL DATA KMAlIt
U4laquo4 +
03H Ji
10
rc a 1 16 oi ii
tiiy 10
OI
II i23 or o 13 -y~ou HO
II 3V III i 3 t
V laquop oot
OM1 SS ne
T an -i IP
Olt zr LTV
3T 001
a -11 2T
10 an 31
-1 raquo 131 UP 3H lf 14 Lpoundshy
it 14 30
IS
Ui O I P A K T M f H T OP COWlf ICfM O A A
NATJONAI V C A T M C n f t K M V l C K
bullbullbullbullbullshy -2 o AIlaquo TIMMRATUM f fKICIPITATIOH
OATI poundt- MMINMAL DATAk
ZP 51 lo icr
011 111
OoT IHf
Ut 003 am
3o 13 ao
4A X 05shy
H4 i IjJyiV131 ooc js
IH oi 01 tL 18 13 a
No 11-7
rivgtp OO| M Hi 03 01
It 12
bull I 41 bull7119 14 ^^ raquo 31 15 lampk n M ho i
Jo -j-
-J
I
Ml H^ I _
amp2ampUi^= LS 0 S 0-f bullTTT
-Vmdash gt U_ bull 1 rOHM I- 11 OI OCPARTMlNT OF COMM(NCC
HO NATIONAL W f A T M f H ftfraquoVlCI
98
Appendix B
Boring Logs
99
X iHECT 1 ff 2
OAT American Drilling amp Bor ini I Co Inc
wo WATH smn EAST PR ov IDENC E ft 1 Town of South Kingstown South K ngstown R I MOLENO X-J
TC 100 RCSS bull ujrMonitorinq Well Installation | South Kinqjtown R I UNC a STA Pf KXICCTHJ LOC ATK3N
bull cfrserrr TO above S MPLES S FNTTO _ _ |laquolaquor A-109 SURF ELEV RE PORTSEr
GROUND WATER O6SE RVATC MS 1 CDREraquolaquo m-T nn75 laquo A 256 - 20 mdash Hew y
Instolled 32ofT-l2 PV C - JO- COMPUTE 111275 K toia 3- I-WI 1-38 TOTAL MRS bdquo10 screen BORING FCACUAM J K lanq MAI rraquo HomnwWI 300 140 IampPCCrc Mamlaquor Fall 24 30 lampaaiona SOLS ENGR
LOCATION OF BORING H ONITOKING WELL
Coung Samplt Tjp Blow per 6 Manure SOU IDENTIFICATION Strata SAMPLE ^^^yV Bloot
foot
Otptni
From- To
el
l
on Sampler
0-6 1 -6-13 12-18
Dentity or
Conmt j
Chang Remark include colo^ graaation Type of tod lie Rao-coMr type condition nordshynetiDntotf time leamt and tie No Pen Rtlt
2 No top sample 5 12
1 loamy fine sand
bull)^ 40 30 36
5- 616 0 23 20 16
noist iense
Brown fine to coarse SAND some fine to coarse gravel Trace silt
^
1 18 18
36 8-0shy57 40 30 V 35
|0-||-6 D 14 24 20 Srown medium to coarse SAND Some fine gravel cobbles
7 IRshy 16
27 75 37 3
IS- I- D 5 14 16 3bull
ISshy 15
42 50 I9--0shy50 65 20-2ll-6 D 9 23 26 bull Jrown fine to coarse SAND Tbullwshy 1Z 75 90
22-0 Trace silt trace fine gravel
124 120 74 60 52 41
7S-ltlaquoil-A DX 71 16 13 wet very dense
Gray-brown fine to coarse SANC Some fine to coarse gravel little silt
H IR u
40 30--0
3C-30-IO
3l4-334
334-3314
38 4-434
D
c
C
C
7 IflO
94 6
we tr j
y se
ft irox
30MOshy
31 -4shy
Gray-brown fine to coarse SAND Trace silt
Gray-brown fine SAND some lilt trace fine gravel
Too of Rock 31 -4shy
Gray-pink GRANITE
6 7
amp
CJ
IltJ A
60
601
IQ mdash
2(
4
5 i Hard
ft 5ome seams bull
GROUND SURFACE TO J 4 U3CD_ ^JVrf bullbull( tutu t to 4o 4 SampM Type Proportion UMd MOB Wtx 3 OfaM on 2OD Sampler SUMMARY-
OOry CCartd WltWen4 Hoc OlolO Canmonieraquoi Don any CoKeem CarMWncy Earm Barrlaquoj 11 14
UPgtUnOigtturod Piuon trite (Oto20dego 0-Kgt Loei it 0-4 Sait 3O+Hofd Rock Corng 14 Kgt-30 laquo4 0 rte 4-8 MSHM Samplet TPTtitPit Ai Auger Vvanefett tarn 2Olo39 3O-M Owlt n laquo-lS Strlf rinit nn v 1
UTiUndlshffbed ThrMOll and bull 33to9O 5O Very 0laquo nraquoe 19-30 V-3trraquof - | OLE NO X-l
TOVH rim - iA it raquotoraquo
100
SHEET 2 o_L
WO WATEt STUET [AST ft OVIDENC pound a i American Drilling amp Bor ing Co Inc
MCLl WQ X- 1 Tt AOORCSS i
LIME A STA KXICCTMJ tuf same as 1 | tame as i LOCATION
W PORTSEf mo OB nj urt eflaquo T
illtPLES S
P
CVTTO nlaquo mun orv
^s f^ Tin i GRCVMO WATER OBSERVATONS CASING SAMPLER CORE BAR
START Typi COMPUTE tome at 1 same aiH
TOTAL MRS BORIMG FOR CMAN n bull IT INSPECTOR SOILS EMM
LOCATION OF BORING u HfVJTneTfi UFI _
8
Counf Blo-t
foot
Dtpllo
From To
0( on SampMr
0-6 f 6-IZ
Moittir
Oonuty or
Contilt
Strata Ctnngc
SOIL OCNTiriCATION Rtmorkt ineHifl cotot grqdotion Typlaquo of Mil etc Roo-axtrPlaquo condition Mrdshynlaquot Drog tun ttomt end tic
SAMPLE
No Ptfl RfK
434-4o4 c
approx 7 minj
per toot 454
Gray pink GRANITE Hard Fairly solid core
lt_4 24
Bottom of Boring 45 -4
-
~
bull 1
GROUND Sorrow Tye
SURHCZ 10
bull OiOry CgtCord WWothod UPUnditiurMd Piston TPlaquoTtraquotPtt AtAuotr VVor
UTltUndinrvd TTMMO bull bulltat
iivnPilaquo(onioni Uraquot4
me OioiOItttt laquoraquo20
wmt Z0ie33
and 361090
c M
C1 5 Si
-SOshy
ASING
IOtgtWtigt bullnlot Dn 10 Loci M Mod 04 SO Dm 1shy Viry 0laquo
s _
TMEN 0 hMl on 200 SoiTBUr laquoity ConcMMt Conorawncy gtbull 0-4 Sort 30shym 4-B MStlfl M BH9 Strtf bull ts-so v-swt bull
t-HOrt Ear Bern RoetCorrt
i ^^^^^ bull
-[MOLE no x-i
101
raquoMEC rAmerican Drilling amp Bor in g Co Inc 1 ofj_ DATE wo WATlaquo smn UST Plaquo IOIDCNC j laquo i
Town of South Kingstown South Kingstown 8 MOLE MO Jlt Z TC rx MCS3
rtprr uAurMonitorina Well Initollation | South KinqitowrxRI UNC A STA P KATIOM ME POCT ^rwT TO above I OFFSZT
uD^r laquorlaquorTTO 6 -109 suw tLEv Sgt louffJOCNO
0 tj Tlmlaquo WOUND WATER 06SCRVATC US gtW Rsdl SING SAM^EH CORE BAH
26 ^_ 12 $TAlaquoT UL 2Z2i Ji r TTP NW ltA sr IJZC Z5 CCOMPLETE
SitLO 3 I-3B- 1-38 TOTAL MAS 41 BOAINO FOACMAN JK1 ana nf ni n MonwwWl 300^ 140 BIT bullK^CT
gttonvrar Foil J^laquo 30mdash Diamond SOOJIEMGM
IE HFII
iCaunq SampM Trplaquo BMMtpw6 UOIIIK- SOIL DCMTIFKATION Siraia SAUPLE Blow DlaquoPIAraquo of on SompMr HtmorU mcJuo cotes gradation Type of Dwuily
pw or CXang writK Roel-eolorlyp condition tvort-From- To Vfoot 0-6 f 6-2 12-18 Coniitt egt rwtiOnAngtimt wamaondtte No Praquon Rtlt
2 Brown fine SAND little silt 2 2-0shy5 15 18 moist Browi fin to coarse SAND 18 5- 6-6 0 14 25 27 vlaquo Troc fin aravel | 25 wy Ifl 11
dlt tns 35 40 38 moist n in-il-i Lgt U 15 18 ie is li1 Irl IS 31 I2-0
~~43 1
A) Jrown coars to medium SAI MD 48 moist Little fine to coarse gravel
|5-IA-Xlaquo 14 47 41 fn D laquo y Little silt rrqa coarse sane 3 18 I1
68 In IS 44 32 34
n ^n-^i-A- w 2o 19 29 wet 4 la -59 lens ltfO no
25-0 2amp bulllaquo- 77 c BOULDER r[ 4 i
27-0 5X ~W 24 24 bullWar- 5 Ifl irown tine to coarse SAND some
dens 29-0- Fine-coars gravel trace silt
30-3I oxx 30 32 30 moist irown -gray fine SANDiom e 6 l rr Vlaquoy 31 -0 silt trace fine oroveTILL
Bottom of Boring 31 -ampbull shyBent casing -pulled out and moved over 4 - washed amp tJrovlaquo casing to 30 -Installed 3C gtof 1-12- PVC - 10 screen
WOUND SUraquoraquofCE TO 3pound 1 yijfD MW t ASIMC TMCJ laquo olaquorod -bor of borina
SomoU T]Fplaquo ProigtuliOraquoH UMd MIOtgtWLx3Orolt lon2OASanlaquoMr SUUMARY-D=Dry CCorad Wlaquoworaquonraquod bullact OiaiO CanM gnMM Daonty CIMIH Caamraquoci EffW 8or^ 2pt
UPiUnairurMd Pition Itnt laquoM2O O- O UKraquolaquo 0-4 Soft 3O-hHard Roelaquo Corrig o- JO M0mlaquo 4-8 MSNff SOTipM 1 p^ 3O-9O OwgtM bull-IS Slid
TPlaquoTraquojraquoPit AAugtr ViVon mini tamt 20to39 UTtundiifir6d TrwMOtf and JSloSO 50-raquobull Vary 0nlaquo [HOLE NO x-2 B-3O V-3Mf lev rim - IAIT raquosectlaquoraquo
102
300 iu 24
1 UMnii ffi 140 laquo 30
CA1INC tf
gt taWCTf
bull 0gtlaquo i R Cook Jr_ R Millineton1 Wttn
I~
1 VAMtl CtMG
1 W HO-t MO
1 Oraquo 1 laquo0~ twt
L 1 laquo-raquo VfcM^lf [wlaquoraquoCI ^ ^ K3Ot III laquo
0-LS D
5-65 D
LlQ 10-115 D
15-16 Tgt
Lraquo 70-51 n
25-26 D
F
I O-O Ci
A Allstate Drill ins Co vi o i
PROVIDING R 1bull raquoraquo uvraquonn~ N M O M I T O P I N G HE1 _^lt -^ PI-Traquo UJU
CUM Town of South Kineraquotown raquoraquo 1 1TA maoer Propolaquolaquod Sit for Slude Disposal nltn
laquo V-449 iampAAtut i a 138 ort STI bull r 42777 CtOuMO IKVtllON
Cill bdquo 258 DA II MN ru 42777 rilaquolaquodO laquoraquoTti rum 1911
AU1TATI
MMUI1 raquolaquogtlaquolaquo laquoKiO itXHHKraquoriOi of sous MUAHI nMTKlion Ot CMlaquoMC|kOraquort tl CO~VH DXltgt raquomlaquo laquotf IMi COIOI C4l II I 1raquo gtlaquo^ Oraquo 1Ol rC t Xgttgt VtfKOe Craquo Mi 1 ft liMraquoK laquo0^tlaquot nfgt
1-2-1 10 TOP SOIL FINE LIGHT BROWN SAND traclaquo of ilt
16-31-17
22-24-21 100 FINE TO MEDIUM LIGHT GRAY SAND trace of fine gravlaquol and raquopoundLt
lfl-37-34 150 LIGHT BROWN FINE TO MEDIUM SAND little poundinlaquo gravel
21-17-15 200 MEDIUM TO COARSE SAND bullomc fine gravel
12-4-10
265
Observation well installed
NOTE No casing blows taktn
bullbull B-23 ow
^w^ 265 I raquo bull raquolaquo bull I W
11 laquot gtbullraquo Vlaquo 14 W gt_ c-shyji bull alaquo bull jraquo VI laquoHshyw bullbull m raquobullbull D-6 raquo Mshy
bull bull laquo Vshy
1
bull bull
I
103
MAMMII Allstate Drilling Co ulaquorr 1 or 1 FftOVIOCKZ H L traquolS mTArm^S MONITOR NR WEL
VNO wr3JJO__raquoraquou_24__ HCU MO P-74 n iu riBwi Town of Slt7H^ Xirpin
mdash^ laquo0J P 1 1 bull ^n^ciit^o TVlaquow^laquott1 bullraquoit wt 140 nu 30 olaquor fBu lkv Waste Disposal Arcai
MUTAH a V-449 R Cook Jr UMlaquoiigti D 1 38 0t| raquoIJ raquo 5277 rlaquo SUMO luvlaquorv-laquow
mdash 5277 fipe -raquoT pfpm 150
H MCIO IMNTlXAflON Of SOU t(kAIlaquoS rrn 0-laquoraquo
5 -SF 01 w in laquobull -raquo ^ lit
D 1-2-2 TOP SOIL V-1-oraquo
15 IPbull FINE TO MEDIUM LIGHT GRAY SAND AND GRAVEL
5-65 D 37-27-35 some silt
10-11 D 20-14-18
15-165 D i 17-14-14 155
BROWN COARSE TO MEDIUM SAND little fine to coarse gravel trace of silt
20-211 D 4-4-2
230 GRAY BROWN VERY FINE SAND
25-26J D 7-8-9 AND SILT 265 fvarvedl
Observation well installed
NOTE No casing blows taken
wta 10 n uuraquo c^imdashbull IgtM laquolaquobull- B-24 ow ~ 14 ltfc laquoraquobull vlaquo^ M laquobull r O 0 fmtt bull W-L 26 5
-0- CgtCmdashgt bull laquolaquobull mdash laquo 1 - raquoraquo 1 gt 1laquo bull 1 gtraquor to bull mdashbull bull bull bulllaquo I t l~laquo 1lt Uraquo mdashbull ) bull 1 gtbull ft 0~ H laquoy bullM ta bull -IN la laquobull OPUM bull($ IMI
mdash H raquo laquo-bull
104
Appendix C
Calibration of Specific Conductance Meters
105
Specific conductance measurements were made using a beckman RB
338 temperature compensating meter and a YSI rtooel 33 salinity
conductivity temperature meter The YSI meter is not
temperature correcting A formula to compensate for temperature
differences to standardize YSI measurements was used (21)
A long probe for the Beckman meter was used to measure conductivity
in the wells Differences in conductivity between the YSI ana
Beckman meters and the Beckman short and long probes exist These
were calibrated in the laboratory using 001 N and 01 N KC1
solutions Values presented are Beckman short probe values The
Beckman long probe values were reduced by 76 and tne YSI values
were multiplied by 11 to adjust to Beckman short probe values The
YSI meter was used in the latter phases of the study for the
stream contamination due to the greater accuracy of the dial readout
scale
Table 7 Specific Conductance Meter Calibration Table
Concentration (KCL) 0001N 001N
Specific Beckman short 145 143 143 1247 1245 12GO
Conductances Beckman long 190 191 188 1639 1650 1665
umhocm 9 25 C YSI 132 131 128 1131 1140 1150
average values Beckman shortBeckman long = 075
Beckman shortYSI = 11
106
Appendix D
Computer program Flow Chart
107
F1g 33 Computer Program Flow Chart-
1TpoundR MAP TCO
NEWPER
WEWSTP CZAX
HEWIT TRANS TCOF ROW COLUMN
Yes
Yes
108 The following is a description of the USGS two-dimensional computer
program Iterative Digital Model for Aquifer Evaluation updated
December 1972 by P C Trescott The program written in Fortran
consists of a MAIN program and six subprograms or subroutines which
themselves are organized into subprogram sections The subroutines and
their sections are listed below
MAIN Program
DATAIN (subroutine) COEF ITER (section) CLAY MAP TRANS NEWPER TCOF
ETRATE COMPUT STORAG
NEWSTP LEAKAG NEWIT1 NEWITO CHECK ROW CWRITE COLUMN STEADY PRNTA OUTPUT DRY BLOCK DATA
The program begins in the MAIN program which controls the sequence
of passage to the subroutines Sequential steps are described in the
program as shown in the flow chart of Fig 32 Emphasis is placed on the
steady state confined aquifer case as applied in this study First data
input is read in the DATAIN subroutine This data includes transmissivities
or permeabilities starting heads storage coefficients and grid spacings
Nodal transmissivity values are then computed for the water-table problem
in the TRANS section (COEF subroutine) This procedure is necessary here
because the subsequent routine for computing iteration parameters (ITER)
keys on nodal transmissivity values which would not have been input to
the water-table problem In the water-table option these would have been
109
computed from given bedrock and water-table elevations to obtain the
saturated thickness component of the transmissivity calculation In this
study water-table option was not used and the transmissivity values were
input directly The program then passes to the ITER section (DATAIN
subroutine) to compute the iteration parameters which expediate or even
cause convergence Next the MAP section (DATAIN subroutine) is utilized
to initialize data for an alphanumeric map if this was requested in the
input options Transmissivities are then computed for the confined
(artesian) aquifer case (water table not specified with input options)
in the TCOF section (COEF subroutine) These coefficients are harmonic
mean values of adjacent nodal transmissivities weighted by grid sizes
Time parameters and pumping data for a new pumping period are then read
in the NEWPER section (DATAIN subroutine) followed by entry into the
NEWSTP section (COMPUT subroutine) which calculates the size of the
time step Leakage coefficients (hydraulic conductivity of the confining
bed divided by confining bed thickness) are next computed in the CLAY
section (COEF subroutine) if leakage was specified in the input data
which was used in this study
A new iteration is then initiated in sections NEWITO (COMPUT
subroutine) NEWITO saves the current head values and compares them to
the updated head values for determining closure This is followed by
nodal transmissivity values being computed for the water table or water-
table artesian conversion problem Transmissivity coefficients are then
computed for the water-table problem in TCOF (COEF subroutine) Total
head values are then computed with the alternating direction implicit
procedure using the Thomas algorithim first along rows in the ROW section
110 and then along columns in the COLUMN section both in the COMPUT subroutine
Then if a solution is not obtained (because the error criteria for
closure is not satisfied) the MAIN program branches back to NEWIT1 subshy
sequent sections TRANS TCOF ROW and COLUMN repeatedly until a
solution at the particular time step is achieved NEWIT1 increments the
iteration counter and is immediately followed by NEWITO The program then
moves to the STEADY section of the COMPUT subroutine to check if the
closure criteria for steady state has been satisfied Output is then
printed in the OUTPUT section of COMPUT if steady state has been reached
or if the particular time step is designated for output
The program then branches back to NEWSTP (COMPUT subroutine) and
moves through the subsequent routines until the last time step in the
pumping period is reached Output is then promoted in the DRY section
of COMPUT if specified in input data If the last pumping period in
the problem has not been reached the program branches back to the
NEWPER section and moves again through subsequent sections otherwise
the program will terminate or start a new problem if one follows
This study was simulated as a steady state problem which can be
simulated by setting the storage coefficient of the aquifer and the
specific storage of the confining bed to zero and using one time step
of any length
111
Appendix E
Computer Data Sheets
RGSEA
10 ROSE HILL LANDFILL MODEL 20 30 40 LEAKAGE 50 60 70 CHECK 80 90 100 HEAD 110 120 1 23 IQ 100 5 001 37E-OU 0 130 100 001 0 0 1 4 0 - 1 - 1 1 - 1 - 1 i i i i i i 1
ISO 1 10 0 1547E-05 01 10 1 1 160 04642 200 200 1 1 i it
1QO 190
CARDS I THROUGH 19 - CODING SHEET
CHEAD
100 110 120 130 131 132 140 141 142 150 151 152 160 161 162 163 164 165 170 171 172 173 174 175 176 177 178 179 1BO 101 190 191 192
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 539
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 58
25
25
25
25
25
25 621
25
25
25
25
25 662
25 25
25
CARD SET 2 - STARTING HEAD MATRIX (FT)
193 194 IVb 196 197 190 200 201 202 210 211 212 220 221 222 223 bull 224 225 230 231 232 233 234 235 236 237 23B 239 240 241 250 251 252 253 254 255
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 23 25 25 25 25 25
25 25 - 25 25 25 25 25 25 25 25 25- 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 - 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25
25 25
25
25 25
25 25
25 25
25
25 25
25
25 25
25
25
25
25 25
25 25
25
25 25
25 25
25 25
25
25
25 25
25
25 25
CARD SET 2 - STARTING HEAD MATRIX (FT) - continued
STORC 1512 FRI 19 FEB 82
100 110 -1 -1 - 1 - 1 0 0 120 130 140 ISO 160 170 100 190 200 210 220 230 240 230 251 260 261 262 263 270 271
CARD SET 3 - STORAGE COEFFICENT
LEAK
100 110 120 02 130 _ 18 02
I ltu 18140 025 150 02015015015 19 deg25
02 160 022 bull-laquo- J1 5 j 1 z laquo- l^
170 015 180 016 laquo02
190 016 OE025
200 02504019022021025 2 5 i S lt03 0252i2 n
230 030 deg23 deg2 deg2 deg2 -02023023 240 022 250 022025025 02
027043 013025
30() 025025025 310 025031 320 024025
CARD SET 5 - AREA OF STEAMBEDAREA OF NODE
120
Appendix F
Bibliography
121 BIBLIOGRAPHY
1 Agpar MA and 0 Langmuir Ground-Water Pollution Potential of a Landfill Above tne Water Table Groundwater V 9 No 6 1971 pp 76-96
2 Allen William B Hahn GW and RA Brackley Availability of Ground Water Upper Pawcatuck River Basin Rhode Island USGS US Government Printing-office GS 66-624 19bb
3 Annual Book of ASTM Standards Part 31 Open Channel Flow Measurement of Water and Waste Water by Weirs D 2034-68 1975
4 Annual Book of ASTM Standards Part 19 Infiltration Rate of Soils in Field Using Double-Ring Infiltrameters D 3385-75 1975
5 Baeaecner MJ and W BacK Hyarogeological Processes and Chemical Reactions of a Landfill Ground Water V 17 no 5 1979 pp 429-437
6 Beck WW Dunn AL and Grover H Emrich Leachate Quality Improvements After Top Sealing1 8th SHwRD MERL Symposium 1982
7 Beckman WK Transient Modeling For Estimating Sustained Aauifer Yield master thesis presented to the University of Rhode Island Kingston RI 1978
8 Bhattacharya PK and HP Patra Direct Current Geoelectric Sounding Elsevier Publishing Co New York 1968 135 p
9 Bouwer H Ground Water Hydrology McGraw-Hill Book Co New Yoric 1978 p 378
10 Braids 0 Cocozza pound Fenn D Isbister J Rous P and B Yarc Procedures Manual for Ground Water Monitoring at Solid Waste Disposal Facilities Environmental Protection Agency530SW-611 Cincinnati Ohio 1977
11 Cartwright K and MR McComas Geophysical Surveys in the Vicinity of Sanitary Landfills in Northeastern Illinois Groundwater V 6 no 5 1968 pp 23-30
12 Cartwright K and Fd Sherman Jr Electrical Earth Resistivity Surveying in Landfill Investigations Reprinted from Proceedings of ohe lOtn Annual Engineering and Soils Engineering Symposium Moscow Idaho 1972
122 13 Clark TP Survey of Ground-Water Protection Methods for
Illinois Landfills Groundwater V 13 no 4 1975 pp 321-331
14 Dunne T and LB Leapold Water in Environmental Planning WH Freeman and Company San Francisco 1978
15 Faro DG Upgrading Hazardous Waste Disposal Sites Remedial Approaches US Environmental Protection Agency500SW-677 Cincinnati Onio 1978
16 Fenn DG Hanley KJ and TV Degeare Use of the Water Balance Method for Predicting Leachate Generation From Solia Waste Disposal Sites US Environmental Protection Agency530SW-lfa8 Cincinnati Ohio 1975
17 Geisser 0 An Electric Analog and Digital Computer Model of the Chipuxet Ground Water^ Aquifer Kingston Rhode Island master thesis presented to the University of Rhode Island Kingston RI 1975
18 Hahn GW Groundwater Map of the Narragansett Pier Quadrangle Rhode Island Rhode Island Water Resources Coordinating Board GWM 5 1959
19 Hemsley William T Koster C Wallace Remedial Technique of Controlling and Treating Low Volume Leachate Discharge USEPA National Conference on Management of Uncontrolled Hazardous Waste Sites Oct 1980
20 Hughes GM RA Landon and RN Farvolden Hydrogeology of Solid Waste Disposal Sites in Northeastern Illinois Final Report to US Environmental Protection Agency PUD SW-l^d Cincinnati Ohio 1971
21 Keller GV and FC Frischknecht Electrical Methods in Geophysical Prospecting Pergamon Press New YorK NY 19bb
22 Kelly WE West Kingston Landfill An Evaluation of Its Effect on Ground-Water Quality Rnoae Island Water Resources Board Water Information Series Report 1975
23 Kelly WE Geoelectric Sounding for Delineating Ground-Water Contamination Groundwater V 14 No 1 1976 pp fa-10
24 Kelly WE Ground-Water Pollution Near a Landfill ASCE Environmental Engineering Division Journal V 10 No EE6 Dec 19b pp nay-nyy
25 Kelly WE personal communication January 1982
123
26 Kelly WE and OW Urish A Study of the Effects of Salt Storage Practices on Surface ana Ground Water Quality in Rhode Island NTIS FHWA-RI-RD-8001 1981 54 p
27 Kimmel GE and OC Braids Leachate Plumes in a Highly Permeable Aauifer Groundwater y 12 no 6 1974 pp 388-393
28 Klefstaa G Senalein LVA ana RC Palmauist Limitations of the Electrical Resistivity Method in Landfill Investigations Groundwater V 13 No 5 1975 pp 418-427
29 Landon RA Application of Hydrogeology to the Selection of Refuse Disposal Sites Groundwater V 7 no b 19b9 pp 9-13
30 Lang SM Bierschenk WH ana WB Allen 1960 Hyaraulic Characteristics of Glacial Outwash in Rhode Island Rhode Islana Water Resources Coordinating Board Bulletin No 3
31 LeGrand HE Patterns of Contaminated Zones of Water in the Ground Water Resources Research v 1 No 1 1965
32 Palmauist R and L Sendlein The Configuration of Contamination Enclaves from Refuse Disposal Sites on Floodplains Grouna Water v 13 no 2 1975 pp 167-181
33 Pinder GF A Digital Model for Aauifer Evaluation Techniaues of Water Resources Investigations of the US Geological Survey Bk 7 Cl 1970
34 Purushattam D Tamxe GR and CM Stoffel Leachate Production at Sanitary Landfill Sites ASCE Environmental Engineering Division Journal V 103 no EE 6 Dec1977 pp 981-988
35 Remson I Fungaroli AA ana AW Lawrence Water Movement in an Unsaturated Sanitary Landfill ASCE Sanitary Engineering Division Journal v 94 no SA2 April1968 pp 307-316
36 Rosenshien JS Gouthier JB and WB Allen Hydrologic Characteristics and Sustained Yield of Principal Ground-Water Units Potowamut-Wickford Area Rhoae Island USGS US Government Printing Office GS 67-324 1968
37 Roux PH and B Vincent Electrical Resistivity Evaluations At Solid Waste Disposal Facilities US Environmental Protection Agency SW-729 Cincinnati Ohio 1978
124
38 Salvato JA Wi lk ie WG and BE Mead Sanitary Landfill Leaching Prevention and Control Water Pollution Control Federation Journal v 43 no 10 Oct 1971 pp 2084-2100
39 Sawyer CN and PL McCarty Chemistry for Environmental Engineering McGraw Hill 1978
40 Stellar RL and P Roux Earth Resist ivi ty Surveys - A Method for Defining Ground-Water Contamination Ground Water v 13 no 2 1975 pp 145-150
41 Todd OK Ground Water Hydrology John Wi ley and Sons Inc New York 1959
42 Tolman AL Ballestero AP Beck WW and GH Emrich Guidance Mannual For Minimizing Pollution From Waste Disposal Sites US Environmental Protection Agency-500SW-677 Cincinnati Ohio 1978
43 Trescott PC Iterative Digital Model for Aauifer Evaluation US Geological Survey Open file report 1972
44 University of Rhode Island Academic Computer Center CalComp Contouring Manual
45 Warner DL Preliminary Field Studies Using Earth Resistivity Measurements for Delineating Zones of Contaminated Ground Water Groundwater v 7 1969 pp 9-16
46 White EF A Report to the Town of S Kingstown Utility Survey Engineering Corp 1967
47 Zohdy AAR A Computer Program for the Calculation of Schlumberger Sounding Curves Over Horizontally Layered Media Using the Method of Convolution US Geological Survey Denver
48 Zohdy AAR Eaton GP and DR Mabey Application of Surface Geophysics to Ground-Water Investigations Technidues of Water-Resources Investigations of the US Geological Survey Book 2 Chapter 01 Washington US Government Printing Office 2401-02543 1974
IV
Preface
This thesis is written according to the Standard plan The
Table of Contents lists sections included in the Main Body of
the thesis The Appendices include relevant material that is
referred to in the thesis Main Bodyand a Bibliography
Table of Contents
Page
Title Page
Approval Sheet
Acknowledgement ii
Thesis Abstract iii
Preface iv
Tab I e of Contents v
List of Tables vi
List of Figures vii
Main Body
Introduction 1
Background 2
Description of Study Area 10
Field Studies and Procedures 15
Model Development 30
Model Calibration 41
Computer Simulations 42
Analysis ana Discussion 55
Remedial Measures and Recommendations 75
Conclusions and Recommendations 83
Appendices
Appendix A Precipitation Records 86
98
Appendix C
106
Appendix E
120
Appendix B Boring Logs
Appendix D Computer Program Flow Chart
Appendix F Bioliography
CaliDration of Specific Conductance Meters in4
Computer Data Sheets Ill
VI
List of Tables
Table
1 Well point Water Elevations 17
2 Seismic Refraction Survey Results 20
3 S tream Fl ows 22
4 Specific Conductances in Well points 26
5 Specific Conductances in Streams and Observation Holes 27
6 Schlumberger Vertical Electrical Sounding Results 27
7 Specific Conductance Meter Calibration Table 105
Vl l
List of Figures
Figure
1 Location Map 2
2 Study Area 3
3 SupplyWel l Locations 4
4 Field Grouna-Water Table Contour Map 5
5 Ground-water Map 12
6 Geology Background Map 13
7 Fluctuation in Water Level in W e l l s 16
8 Seismic Survey Location 19
9 We i r Locations and Water Level Ranges 21
10 Surface Contamination Monitoring Locations 24
11 Fluctuation in Specific Conductance in W e l l s 25
12 Electrical Resist iv i ty Sounding Location 28
1 3 Model Grid 31
14 Simulated Ground Water Table Contour Map 32
1 5 Northern Drainage Area 34
16 Landfill West-East Cross-section between Wells W and EC 39
17 Landfill North-South Cross-section between Wells NW and SC40
18 Natural Conditions 43
19 Excavation without Landfill 45
20 Landfill without Excavation 46
21 Landfill Head Contour Cross-section 47
22 Landfill and Excavation with Dam 49
23 Summer Condition 52
24 Landfill ana Excavation without Dam 54
VI 1
25 Infiltrometer Location and Drainage Feature 57
26 Results of Infiltrometer Tests 59
27 Schlumberger Sounding R-l 71
28 Schlumberger Sounding R-2 72
29 No Recharge over Lanafill 77
30 SI urry Wall 80
31 Slurry Wall without Recnarge Over It or Landfill 81
32 Precipitation Record 87
33 Computer Program Flow Chart 107
Introduction
Ground-water contamination of aauifers from municipal landfills
is a widespread problem Contamination of domestic supply wells and
neighboring streams has occured at the South Kingstown municipal
landfill which is located adjacent to Rose H i l l Road approximately
one mile nortn of Peace Dale Rhode Island (Fig 12) The polluted
neighboring wells have been relocated to their present locations to
remove them from tne leacnate plume (Fig 3) Fig 4 inaicates flow
patterns from the landfill which has contaminated streams to the
east and southwest of it The generation of leachate continues as
precipitation recharge and upgradient ground-water sources
infiltrate the refuse To effectively prevent or minimize
contamination from this landfill several remedial options are
available These w i l l be evaluated relative to the areas geologic
setting and hydraulic properties ground-water flow patterns
recharge characteristics and proximity to supply sources
The rate of ground-water flow out of the landfill into the
adjacent aauifer and flow patterns largely depend on tne hydraulic
gradient of the water table and the hydraulic conductivity of the
landfill and aduifer material The hydraulic gradients were
determined by monitoring water-table fluctuations in several wells
located around the landfill and elevation siting in stream
locations and elevations This information enabled a ground-water
map of the area to be developed from where flow patterns can be
developed assuming flow lines are orthogonal to contour lines The
ground-water map in combination with Knowing aquifer and landfill
N
^ooo
feet
Fig 1 Location Map
3
peoy ||H asoa
X ltbull
Alt
f c c
o
^ ^ o o f a
O OJ 83X1
o O
x o
seepage observation -t West
hole Landfill Area
Legend mdash landfill limit bull j--excavation limit r^-s stream copy WNWNEECSeuroSCSEN
monitoring well locations = = = unimproved road
A contaminated domesti supply well
D uncontaminated domestic supply well
feet
Fig 3 Supply Well Locations
5
a 03
N lo ^ gt
laquo c 2
mdash w
3
X o ^
3 O L
o CO
0 opound E bullo
0
co
c
o0
uj ^
0 o o c
o $ bullA
E c o
w
bullo t_hraquo9 O
_OplusmnJ ca
u
pro
ve I 51 H
bullo 0gt
UJ _c e poundbullo Mzbull w gt 0
laquorege cc
0gt -^^ o a5 raquobull bullo o sect 3 mdash laquoo o wcz _
3Ogt c $c o_ X
aw e 05 0 (0 3 bullo
o a 2 2 u
hydraulic properties and the subsurface geometry enable estimates of
ground-water outflow to be made Streamflow measurements were used
to verify these outflows Contamination levels using specific
conductance measurements as an indicator were measured in wells
streams and observation holes to help delineate the extent ana
degree of contamination An electrical resistivity sounding was
conducted in a known contamination zone
The primary objective of tnis study is to determine flow
patterns in the vicinity of the landfill ana recommend possible
actions to contain or minimize the impact of the contamination In
oraer to fully evaluate these goals the aforementioned parameters
were input to a computer model to produce simulated flow patterns
under different conditions The simulated present conditions were
matched with field water table and stream flow measurements to
calibrate the model A series of simulations were then run to
evaluate flow conditions before the excavations anaor landfill
existed Remedial measures such as reducing recharge to the
landfill and implementing a slurry wall to blocx off leachate flow
to endangered wells were simulated to evaluate their effectiveness
Based on this analysis recommendations are made as to how to
minimize leachate production ano best alleviate the immediate danger
of the contaminant plume spreading to unpolluted domestic supply
wells
background
The South Kingstown landfill is in a geologic setting that is
very similiar to the nearby West Kingston landfill This is located
about 3 miles west of the South Kingstown landfill and has been
studied to assess leachate effects on groundwater quality using
specific conductance as an indicator of contamination levels
(222ltt) Both sites were located in abandoned gravel Quarries which
were filled in with refuse to create the landfill
In the literature numerous authors have shown that the character
of contaminant plumes from landfills are largely dependent on the
local geology and geohydrology A study on Long Island (27) in
similiar glacial material illustrates that the Quantity of flow is
dependent on the hydraulic conductivity of tne aauifer the
hydraulic gradient and the vertical cross-sectional area of the
aauifer it flows through This is expressed as Darcys Law (41)
Q = KIA
wnere Q = flow quantity
I = hydraulic gradient
K = hydraulic conductivity of the aauifer
A = vertical cross sectional area of the flow area
Specific conductance was used as a contaminant tracer to show that
the plume from the landfill flowed downgradient and vertically
through the full thickness of the aauifer A study in Iowa (32)
indicates that the size ana shape of the contamination outflow from
a l a n d f i l l can be predicted from existing geohydrologic conditions
and that the horizontal shape of the outflow extends downgradient
8
from the source and parallel to ground-water flow lines Other
parameters which control the extent of the contaminant plume are
dilution and dispersion in the aquifer and the adsorption properties
of the aauifer material (31)
The amount of leachate generated depends largely on the amount
of water that infiltrates through the landfill to increase tne water
content of the refuse in the landfill The precipitation recharge
that percolates down through the unsaturated zone to the water table
moves in a vertical direction (35) Surface runoff soil moisture
storage losses and evapotranspiration account for tne precipitation
that is not transmitted tnrough the unsaturated zone of aeration
(3315) Upon reaching the saturated zone the water enters the
ground-water flow system Ground-water mounding has been reported
in landfills due to the decreased hydraulic conductivity of
compacted refuse relative to surrounding aauifer material (20)
Chemical processes within the landfill leachate outflow and
surrounding soil cation exchange capacity relative to water duality
of the surrounding aduifer have been studied in Pennsylvania (1) anu
in Delaware (5) A procedures manual for ground-water monitoring at
solid waste disposal facilities was developed by the US
Environmental Protection Agency (USEPA) (9)
Several reports have been written that investigate site
selection design criteria and remedial measures to correct
leachate problems (29) A survey of ground-water protection methods
for landfills in Illinois studies relationships to the water table
theory of liner installation and monitoring devices (13) Sanitary
Landfi11-Leaching Prevention and Control presents a review of
preventative methods such as means to minimize infiltration
interception of ground-water and other pollution control measures
(2 37) A study in Pennsylvania on actual measures implemented to
collect and treat a landfills leachate discharge presents a site
specific study (19) Leachate Quality Improvements After Top
Sealing1 shows that by minimizing infiltration at a landfill in
Connecticut the outflow leachate water quality can be improved
dramatically and contamination plume reduced significantly (6) The
most comprehensive reports on remedial approaches to upgrading waste
disposal sites and ground-water protection methods have been
compiled under USEPA contract (1542)
To assist in evaluating remedial measures the US Geological
Survey (USGS) computer model Iterative Digital Model for Aduifer
Evaluation was used It was originally developed as a model for
simulating two-dimensional aauifer problems (33) It had been
updated since its original development to accomodate different
options (43) This model has been applied to glacial outwash
regions in Rhode Island (717)
10
Description of Study Area
A map of tne landfill area (Fig Z) was obtained from tne town
of South Kingstown The excavation to the west of Rose Hill Roaa
the landfill area directly to the east and the presently operating
area to the east of the central stream comprise tne overall study
area This study will concentrate on the west landfill area whicn
has recently reached capacity and been closed to further dumping
This site received mixed refuse for the past 15 years The depth of
the excavation where the landfill presently exists was approximately
to bedrock in some places Tne exact depths of landfill material is
unknown
The landfill cover has been graded and sloped generally eastward
to convey surface runoff to the eastern side A sandy soil that was
excavated locally was used as tne cover material The northern
section has a vegetation cover and the recently filled southern
section has been seeded and mulched The six monitoring wells W
NW NE EC SE SC were placed by the town of South Kingstown to
provide water quality information
Referring to Fig 2 the west excavation stream drains the area
created by the excavation to the west of Rose Hill Road and flows
throughout the year The central stream drains a small watershed
area which lies to the northwest of the landfill and drys up during
part of the year These streams flow into the Saugatucket River
which flows throughout the year and is larger than the west and
central streams combined
11
The USGS Groundwater Map (18) was initially consulted to proviae
information on the ground-water flow patterns (Fig 5) and the
geology of tne area (Fig 6) The surficial geology borings and the
vertical geologic cross-section at the base of the study area
indicate shallow water table and bedrocic and a nearly constant
saturated thickness (18) Boring logs at the W well ana a point
approximately 150 feet south of it indicate glacial outwasn material
which is primarily sana with a trace of gravel over bedrock at a
depth of approximately 33 feet Borings at the east landfill area N
and S monitoring wells indicate the same aquifer material
(Appendix B)
The ground-water map developed by Hahn is taken as
representative of conditions existing prior to the excavation of the
I l andfill (18) This indicates water-table contour lines that run in i
a general northeasterly direction This means tnat flow was
originally in a southeasterly direction However contamination of
domestic supply wells on the west side of Rose Hill Road has
occurred (Fig 3) strongly suggesting that the original flow pattern
has been altered by the excavation to the west of Rose Hill Road and
the landfill to the east of it Domestic supply wells were formerly
located directly to the west of Rose Hill Road but were aoandoned
when they became contaminated from landfill leachate New wells
were located to the south and west away from the contaminant plume
of tne landfill In addition a well located at the northeastern
corner of the landfill was contaminated and a replacement located to
the east of Us former location on tne opposite side of the central
12
Legend scale 124000
mdash-40 mdashground-water contour elevation
Fig 5 Ground-Water Map
13
Legend feet
TILL
Fig 6 Geology Background Map
14
stream This second wel 1 also became contaminated Domestic supply
wells located near tne northwestern corner of tne landfill and
approximately 300 feet south of it nave remained uncontaminated
These well locations serve as an indication of tne extent of the
landfill contamination which is largely dependent on the groundwater
flow patterns To furtner investigate this problem and provide
substantial information on which to base the geohydrologic analysis
field studies of the area were conducted
15
Field Studies ana Procedures
A map of the lanafill and an aerial pnotograph of the area were
obtained A tracing of these maps superimposed upon another
delineates stream landfill and monitor well locations (Fig 2)
The field investigation concentrated on the west landfill area ana
its aajoining streams ana monitor wells The east landfill area and
the three monitor wells in that area are induced in the latter
phase of the study in oraer to expand the model area
A traverse which establishea tne monitor well elevations was run
using a Carl Zeiss level These were originally sitea in by the
town of South Kingstown using a local USGS reference datum number 40
(18) The wells of known elevations then served as benchmarks for
referencing adjacent stream elevations This in combination with
the depth to water table measurements at each well enables tne
water-table surface geometry of the area to oe visualized
Water-table measurements of the west landfills wells were recordea
over a ten month period to record fluctuations (Fig 7 Table 1)
The east landfill areas wells were monitored for a five month
period Using a given water-table condition a ground-water map was
developea of the area (Fig 4) This indicates an outflow from
the landfill primarily in a southeasterly direction and partially
in a southwesterly direction
Additional bedrock and water-table information was ootainea by a
seismic refraction survey at several locations along the landfill
perimeter A Bison Model lb70C Signal Enhancement Seismograpn was
used to maxe the surveys Lines were run (to a length of kOO feet)
16
17
w s p bdquo S bdquo s S S a laquolaquo _
s 2 8
V
r bdquo
3 s a
-R s
S
S 3
t
raquobullraquo
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5
K
r
~
3
K
pound
7
S
bdquo3
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shy raquo S s
1 3 s 3 2 5 ^ bull
5 m
s o
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--
R bull 5
s pound J O s
5 a 3 7 3 m
5 s a ^
iraquo a s rlaquo
M ^
^ c o 2 5 s 3 a S R
rd 3 y a O =J
^ bdquo
JJ s s 3 bull ~ I
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(Ogt (U
2
-t =
r s s in
5 y
a s
5
3
s
5 a
^ a
3 a 51 a bullbull
sj 5 Ml
3 a bull
s raquo
a
0)
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^ mdash
a j -
-3
C
g S
S
bull a
-
~ 3 o
2 s s 3 a bdquo s s $ Al s
(1) = $ s 3
S
c a a
3 e 5 s N s S a - 3 = s s a 5
a s s - 3 S shy
4
0
a s
bdquo tfH
bdquo
3 a
bdquo
s a
e bullfl s i s s a s a
3 nt
s s 3
g laquo s3 a
~ J s 2 a s o s S s 3 a a j laquo s o s
3 bull laquobull
2 a 7 3 a 3 a ^2
s mdash 5i o
bull bull
mdash
3 o
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18
in both directions to provide a check and permit accurate estimates
of the depth to bedrockThe seismic results allow approximate
interpretations of the depth to the water table and bedrocK thus
permitting an estimation of the saturated thickness Ground
elevations at the location of the seismic surveys were determined
from a topographical map and field siting From this information
water table ana bedrock elevations estimates were made Bedrock
contours are listed in Fig 8 In addition a table which
summarizes the seismic refraction results for the unsaturated
saturated and bedrock layers velocities and depths at each survey
location is presented in Table 2
Scream gauging stations were established on the two streams
bordering the west landfill (Fig 9) Three stations were placed on
the central stream These provide information on the influent or
effluent condition of ground-water flow in the upper sections of the
stream and ground-water baseflow from an area adjacent to the
landfill into the stream (Table 3)
The stream gauging stations used were 90deg V-notch weirs The
weirs located in the SE and SW positions were placed in the
streamoea with a liner of plastic upstream to minimize underflow
The weirs located in the NW and E positions were cut to fit in
recesses of concrete culvert pipes Concrete plywooa interfaces
were coated with roofing cement to minimize bypass flow Upstream
water pressure and a snug fit hold the plywood sections in place
All weirs were implaceo according to AigtTM reouirements and flowrates
calculated using the standard 90deg V-notch formula (3)
19
N
seepage West observat ion Landfill hole
Area
Legend landfill limit excavat ion limit
copyWNWNEECSESC monitoring well locations
= = = unimproved road -- WNES-number
seismic refraction locations
-40shy approximate bedrock contpur elevation
feet
Fig8 Seismte Survey Location
20
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co CM o on on CO CM CTNVO VO co CM o on on Q gt_x rH oj on a oj on a - rH oner
rmdash on sr i i
M z Z
gt gt gt
X-N CO laquomdashv CO CO bull igt gt bull
1 gt fc^gtgt bullbull ^ ^ ^
C 4-gt O t igt O J- 4J O H m o o o 3 bullH CO O rH in 3 bullH co vo o in 3 ~ 1 i-k -i ^trade fj rj ui ij o CO o n o rH =r co o n vo vo vo co o bullv O O O
O raquo On-3 rH O -bull- rH ON in _ IH in oj - rH bull rH VO OrH bull rH On ON pH d)u CO -UCO 4J OJ CO 4-gt gt
C mdashbull gt CM gt CM H-l O CO
v- ^^ N C 0
bull0 N CO
4-5 -0 _c^gt in in CO CO
C x~ c -^ t-oo in i 4J j_gt 41 4J bull 9 bull bull 4J bull
o j ON O O 3 (0 O4J O ON ON QJJ t~-^3- OJ 4-gt L
CO CM trade CO CM rH rH OJ co CM oj on Q ^ _ CO 3~Q-- n 45 Q mdash OJ OJ OJ C (0
1 11 3 nZ 2CO
gti gt gt CO CO CO ^-x m -s CO
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3 bullH CJ O O in 3 bullH CO Cmdash VO on 3 pound-laquo H CO o n in inco co o n ma- r co g^ 5sect^ o
o rH on oj O bull- rH ONCO L O_ rH OJ VO M
rH bull rH =t rH bull - OJ T CO CO M CO 4-gt rH CO -U rH CO 4-) s
uits
CO 4-gt 4-5 T3 gt CM gt CM gt CM cc CO CO CO
3 3gt oa tlp^ CO O CM O gt 4J O 40 i 3 r+ k C pound JS
CO pound
^^ s -bullgt cmdash on poundZ VO CTI trx 4J 4J 4J
) bull bull bull Q Q Q Q4J 3shyc O-JJ CTgt OJ OJ Q-IJ inco on CO CO CO o co CM oj on co CM oj on co CM on
Q Q QON^ Q bullH Q^
rH rH 4J rH
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i gtgt rH oj on gt tgtshyCM ^ cO^-s CO ~ CO
CO CO J X fc^_ bull^gt bullgtgt bull gt gtgt bull gt CO
j_ jJ O pound- Jj -P O Li deg =fObullH co on f- ^ 3bullH CO CO O in 3bullH CO
g^ -^2
poundsect HO
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3 CO in in in in in in co o n co o n
o -^ r oj in O rHCO CO rH bullrH bull rH =T OrH bull rH OJ f-CO 4J bull- CO 4J rH O0) J-)
gt CM gt CM gt CM 4J
CO N_^ m^
bull OJ
t t poundshyCO CO CO CO rH J3 gt r-t oj on gt r-i oj on gt gt r n o j o n
lto co lto CO T bull ii-4 laquomdash bullmdashH
bullo CO L L 0)
CM CO cc
21
N
545-594
seepage observation
hole West Landfill
0NE I47-509
Area
Weir 45
i487-531
0 EC Al3-467
Legend bullmdash landfill limit -bull---excavation limit r-s stream
copy WNWNEECSESCSEN monitoring well locations
= = = unimproved road
Weir location and elevation
feet
Fig 9 Weir Locations and Wate r Level Ranges
22
JT NO
S shy S
O
bull ry m
oa
NO
(M raquo 1 03 or NO m
JT O O raquo
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i ru
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i O
i ^
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r-laquo
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1 pound OJ
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3 bull o a
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5 laquo15
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23
A field study to determine the infiltration capacity of a
section of tne landfill topcover was conaucted A modified version
of a double ring infiltrometer was used to study infiltration rates
(4) The cylinder diameters useo in this study were 8 inches and 18
inches A constant head of 6 in was maintained in the
infiltrometer and rates of infiltration were determined Tnese
results and an analysis of surface infiltration into the landfill
are included in tne analysis and discussion section
Specific conductance levels in the monitoring wells in the
streams bordering the landfill and at observation holes near the
landfill were measured (Fig 10) This is a good indication of the
mineralization of water (39) Specific conductances were measured
intermittently over the ten month period to develop a picture of the
extent and degree of contamination in the wells (Fig 11 Taole4j
and in the surface contamination monitoring locations (Fig 11
Table 5) A comparative standardization of the Beckman (short and
long probes) and YSI specific conductances is in Appendix C
A surface electrical sounding using the Schlumberger array was
conducted adjacent to Rose Hill Road at the R-l location (Fig 12)
in an attempt to delineate the vertical extent of the contamination
zone Well W was used as a centerpoint and a reference for
water-table depth pore water conductivity and depth to bedrock A
Schlumberger array electrical resistivity sounding was also
conducted in an uncontaminated area at tne R-2 location (Fig 12) to
provide a comparison background interpretation A seismic
refraction survey N-4 was conducted at the same location (Fig 8J to
24
N
excavat ion
Seepage West observat ion Landfill hole
Area
Stream 1 Seasonal observation 0 EC
hole
East Stream2
Legend sw Weir landfill limit j--1--^ excavation limit
copyWNWNEECSESC monitoring well locations
== unimproved road
feet
Fig 10 Surface Contamination Monitoring Locations
25
8000T
7000
O bull U) W6000
Legend
0 sc A NE O W
A SE O N W
a EC
1 O N D J F M M
Time months Flg11 Flucuatlon In Specific Conductance in Wells
26
Table 4 Specific Conductances in Wells (pmhoscm at 25degC)
West East Landfill Landfill
Date NW NE EG SE W SC N E S
81581 851 938 236 2356
102981 171 3268
11381 3268
111081 304 988 1100 258 3800
111481 426 2736 1216 186 4560
111781 304 3610 433 389 4560
121981 380 1406 129 103 380
1982 160 152
31582 274 760 1064 61 334 8000+ 182 53 84
52182 450 1500 1125 112 712 8000+ 175 255 150
52282 425 1320 1200 110 850 180 320 170
27
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t CM0gt s o o o in rA n ^o oo in tmdash oo 0gt zr =r a- JT JT$_
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bull_bulllaquo
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4)bull
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U ^ raquo ^ - ~ raquo O ^ ^ O t ~ C O r H - r r ^ - ^ ^ JJ r H C M v O r H r H r H r H r H C M C M r H i n c r gt rH CO CM gt laquolaquo - - -^ bullmdash mdash bullraquoraquobullgt -v -v ^^
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in rH cmdash
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CTgt rH raquo CM rH
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tmdash fshy
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28
excavation
West Landfill
Area
Legend bullmdash landfill limit -bullbull--bullexcavation limit r~~s stream
copy WNWNEECSESCSEN monitoring well locations
= == unimproved road
electrical resistivity sounding
feet Fig12 Electrical Resistivity Sounding Location
L
29
allow estimates of depth to water table and bedrocic to be made
Soundings were carried out to 500 foot electrode spacings to insure
that hredrock was penetrated and to facilitate interpretation These
results and a discussion of the soundings interpretation are
included in the analysis and discussion section Schlumoerger
resistivity soundings were made using a Soiltest R-bO unit
30
Model Development
The USGS Iterative Digital Model for Aauifer Evaluation was
usea to develop steady state flow models of the study area (43) A
flow chart of the computer model and a brief explanation of the
subroutines usea is presented in Appendix D The stream locations
elevations and aauiferlandfil1 geometry and hydraulic properties
were input to the model to compute head values at each 200 foot
grid spacing node (Fig 13) The input data which is for the
existing excavation and landfill conditon is listed in Appendix E
The head values that are computed at each grid space are in turn
loaded into the CalComp plotting routine (44) where a grid spacing
is setup with the computed head values at each node The contouring
program linearly interpolates between these head values and
generates a contour map The computer simulated ground-water
contour map for the excavation and landfill is presented in Fig
14
The streams in the model generally serve as controlling boundary
conditions When using computer simulated geohydrologic models of
an area choosing the boundary conditions for the model that are the
same as prevailing conditions in the field is a critical step in
model development Extending the models boundaries to areas in the
field that have a minimum influx of ground-water across them
simplifies the proolem of calculating fluxes from outside the model
area The eastern boundary is bordered by glacial till which has a
low hydraulic conductivity estimated to be 67 ftday(2) This
contrasts to the high hydraulic conductivity of glacial outwash that
makes up the model area of approximately 107 ftday(3036j
31 N
o 9
bullO O
32
33
The Saugatucket River serves as the controlling boundary on the
east A small drainage area directly to the east of it provides a
minimal influx
Beyond the moaels northern boundary the glacial outwash valley
extends to the base of a till covered h i l l on the western half ana
on the eastern side extends along the Saugatucket stream Due to
the relatively large drainage area that lies upgradient from the
northern boundary a recharge flux eduivalent to 10 inyr over the
drainage area on the till hill and outwash area north of the model
area was input as underflow (Fig Ib) Part of this was input at
each northern boundary node Till has a lower infiltration capacity
than outwash so more of the precipitation w i l l be transmitted as
overland runoff resulting in a lower ground-water baseflow The 10
inyr of recharge that results in a ground-water inflow from the
combined till and outwash region represents an estimate that is
smaller than the 14 inyr recharge for glacial outwash areas in
Rhode Island (25)
The glacial outwash valley extends beyond the western boundary
No significant ground-water recharge flux was estimated at this
boundary A relatively low ground-water gradient exists to the west
of this which does not provide a significant flux across this
boundary Tne southern boundary is basically the outflow region for
the area and therefore would not reauire any ground-water flux into
the moael area across this boundary This boundary was set south of
the point that the streams in the model merge together Therefore
the streams which lie to the north of it are the controlling
34
scale 124000
Fig 15 Northern Drainage Area
35
boundary conditions The flux out of the downgradient outflow
region approximately eauals the influx from precipitation recharge
and boundary influxes
When tne stream configuration in the moael area are reviewed it
can be seen that they comprise a large portion of the boundary
area The screams can act as sources or sinks for water in the
model thus providing to and removing water from the aquifer The
leakance option was used in the model which provides for a confining
bed and aouifer area beneath the stream to be input
The leakance is defined as the hydraulic conductance of the
streambed divided by the streambed thickness which in this case is
taken as 1 foot The leakance value at each streambed node
restricts the flow between the aduifer and the stream The
streambed hydraulic conductivity is typically 01 the value of tne
hydraulic conductivity of the aduifer (717) The value 107
ftday was used for a streambed conductivity based on a value of
107 ftday for the aquifer The aduifer and stream hydraulic
inputoutput exchange at eacn node is calculated by initially
finding the difference between the initial field stream head
elevations and the computed head elevation values at the
corresponding nodes This head value is then multiplied by the
(Leakance value at each node) x (stream area of each node)
Therefore if the aduifer head was lower than the stream head the
stream would act as a source of water for the aquifer and vice
versa
36
Tne leaxance input at each stream node is the ratio of the
actual field streambed area in each node to the area of each node
which is 200 ft x 200 ft = 4 x 104 ft2 The west
excavations stream width is approximately 3 ft central 4 ft and
east 5 ft Therefore if tne west stream traverses the node
directly without meandering it presents a leakance of 3 ft x 200
ft4 x 104 ft = 015 Leakance and streamhead values were
input at each node to set up the stream flow parameters in the
models
A recharge value of 14 inyr over the entire area was input at
each node This represents a value of precipitation that is
transmuted into tne ground-water rather than being directly
evaporated evapotranspired through plants or overland flow
runoff The precipitation recharge flow from the stream into the
aauifer and boundary fluxes provide the model witn input flow
parameters
From analyzing the available information it was determined that
the study area lies within a glacial outwash area with a relatively
shallow bedrock The seismic survey around the landfill generally
indicates a depth to bedrock below the land surface of approximately
29-43 ft with corresponding saturated thicknesses of 19-33 ft as
seen in Table 2 This agrees with borings from tne USGS groundwater
map in the stuuy area (18j The seismic survey was run at a low
water table condition which was several feet below the high water
table level (Fig 9)
37
High water-table saturated thicknesses were used to develop
model parameters For the purpose of this model study the saturated
thickness was set at 30 ft except in the vicinity of well W where
there is a bedrock high (Fig 8) At this location a high water
table saturateo tnicxness of 8 ft was estimated In tne vicinity
the seismic survey was conducted the bedrock elevation at this
location is the highest and the saturated thickness the least Tnis
can be seen by an east-west cross section of tne landfill (Fig 16
The boring log for well W indicates a sand trace gravel outwash
material (Appendix B) Boring logs at the eastern landfill area N
and E indicate similar material On this basis the hydraulic
conductivity was estimated at 107 ftday (3036) Witn the
exception of the landfill and the bedrock hign areas the
transmissivity values were set at 107 ftday x 30 ft = 3210
fto day From the literature the hydraulic conductivity of the
landfill material was estimated at I ftday (19) The
transmissivity of the landfill material in tne nortnern section was
estimatea at 1 ftday x 30 ft = 30 ft^day or approximately two
orders of magnitude lower than the outwash In tne landfills
southern section the original excavation was not as deep as in the
northern parts The landfill material was estimated to makeup only
one half tne saturated depth the remainder being the original
glacial outwash material (Fig 17) Therefore the transmissivity
at the southern end was estimated at 15 ft x 107 ftday + lb ft x
1 ftday = 1620 ft^day These values were graded into the 30
ft^day values at the landfills northern halfway point These
38
were input as transmissivity values to the model at their respective
locations This model did not use the water taole option so
water-table fluctuations did not affect the transmissivities
39
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40
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Model Calibration
A simulation was run using the initial estimates of stream
parameters aquifer and landfill hydraulic conductivities
transmissivities boundary and recharge conditions to approximate
water taole conditions in tne fiela Initially the existing
condition of the excavation area to tne west of Rose Hill Road and
the landfill to tne east were modeled in order to calibrate the
model to current field conditions as shown on Fig 4 The simulated
well values (Fig 14) fall within tne range of field values (Fig
9) The resulting contours also provide an approximate matcn This
can be seen by comparing Fig 4 with Fig 14 An additional check
was to match the flow loss and gain in the streams between tne weirs
in the central stream which w i l l be discussed later The
simulated flow value from the excavation drainage stream is the same
as that measured at the SW weir location Having calibrated the
model by approximately matching well water levels nead contours
and scream flow values different field conditions and possible
remedial measures can be simulated
When the model grid was laid out over the study area as viewed on
Fig 13 the stream configuration rarely traversed the grid nodes near
their central axis When the stream locations were input to the
computer the information was documented as crossing the central axis
of the grid nodes The result of this is a slight aberration when
the actual stream configuration is laid over the computer graphics
head contour output The streams dont always cross the groundshy
water contour at the logical location Rather than modifying the
actual stream configuration to adjust then to the computer output
their actual locations are presented
42
Simulations
i The primary focus of the computer modeling is to analyze flow
patterns under changing conaitions in the near vicinity of tne raquo
landfill The study areas overall flow patterns as they exist
today are first presented in order to realize the lateral east-west
head contour lines between the stream that directly borders the
landfill on the east side and the SaugatucKet stream (Fig 14)
This indicates a general southerly flow direction in that area As
different conditions are modeled these contours generally maintain
their east-west orientation In order to facilitate interpretation
of flow patterns in the near vicinity of the landfill flow patterns
to the west of the stream that borders the east side of the landfill
r are presented in the subseauent models
L- Natural Conditions
The results of modeling the original natural conditions are
shown in Fig 18 The excavation and stream to tne west of Rose
Hill Road and tne landfill did not exist in this simulation The
southwestern boundary consists of a drainage stream that was
delineated using an aerial photograph and stream elevations were set
using the topographical map The USGS ground-water map (18) was
used to estimate head values between the west excavation and north
streams These were input to the model as constant heads on the
models western boundary The resulting simulation generally matches
the southeasterly flow direction that is indicated on the
ground-water map (Fig 5)
A3
Legend
x-^- stream 400 = = = unimproved road
I f ee t
Fig 18 Natural Conditions
44
Excavation Without Landfill
The condition of the excavation to the west of Rose Hill Road
with its resultant drainage stream without the landfill was modeled
next (Fig 19) The extent of the excavation ana the location of
the new drainage stream were delineated using the aerial
photograph The west stream elevations were sited in the field and
used in the model The concept of a confining streamoed layer was
excluded in tne excavation drainage stream under the concept tnat no
significant organic layer had been built up within the 25 year
period that the excavation had been initiated Head values between
the west and north stream boundaries were interpolated and input as
constant head values on the northwestern boundary The west
excavation drainage stream creates a condition that alters the
natural ground-water flow patterns by creating a more southerly flow
condition the drainage stream providing a more immediate surface
outflow in that area
Landfill Without Excavation
The hypothetical case of a landfill without the excavation was
modeled next (Fig 20) The low hydraulic conductivity zone of the
landfill changes the natural flow conditions and creates noticeable
mounding This is evidenced by the decreased spacing of the head
contour lines and deviation from the lateral contour lines of the
natural conditions and higher head values (Fig 21)
45
Legend
excava t i on s t ream
400 unimproved road
f e e t
Fig19 Excavat ion without Landfill
46
Legend
landfill limit
bull - s t ream 400 copy WNWNEECSESC
monitoring well locations f ee t bullbull-bull=bull unimproved road
Fig 20 Landfill without Excavation
1
oin CM
bull
m u
0)rf
oO
bullo 9
bullo 9
o rf o o CO 1
lt0inO O
T ^ogt
c o
47
o9 aI 0)
ot_3 O laquolaquo coO bull3 OJ oX
bulla caj
CM
UO|IBAraquo|
48
Landfill ana Excavation
The condition of tne existing landfill and the excavation with
the dam is the next condition modeled (Fig 22) The ground-water
elevations used to calibrate tne model correspond to an actual high
water table condition Between the NVJ and pound weir a streamflow loss
of approximately 102 gpm occurs aoout 60 percent of this flow is
lost at the dam site which maintains a head of b-6 feet over an area
of approximately 1800 feet^ This approximates a field value of
1144 gpm influent to the aduifer between the NW and E weir on ]2
December 1981 (Table 3) From the E weir to the SE weir a net
increase in flow occurred of 74 gpm which corresponds to field
increase of b62 gpm
The surface runoff from tne landfill flows primarily toward tne
eastern side of the landfill Increases in water-table elevations
on the eastern side after heavy rains such as the 11 November 1981
storm indicates that this runoff increases outflow gradients to the
stream and therefore increases streamflow Surface runoff input is
not modeled which explains in part why field stream inflow values
are slightly higher than model predictions especially for periods
after a storm has occurred The flow from the SW weir located at
the southern end of the excavation represents drainage outflows from
that area The net flow calculated in the model was 140 gpm
which approximates field conditions of 1642 gpm on
December 9 1981
49
d f l f reg N E
shy
Legend
landfill limit -bullgt-bullgt- excavation ^-N_X- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road
-40mdash approximate groundwater contour
400
feet
Fig 22 Landfill and Excavation with Dam
50
The modeled flow patterns suggest how the various contamination
zones around the landfill have developed to their present state
They indicate a flow to both the southeast and southwest on their
respective sides of the groundwater divide Evidence of a
southwesterly contaminant flow is presented when the continued high
specific conductance contaminant level in tne observation seepage
hole is realized (Table 5 ) In addition the specific conductance
increase in the west excavation stream is evidence of an influent
contamination flow
Contamination flow to the eastern and southeastern side of the
landfill is obvious High specific conductance levels in the wells
on the eastern side (Table 4 ) a specific conductance increase
between the E and SE weirs (Table 5 ) and contamination in the NE
domestic supply well (Fig 3) present conclusive evidence of
contamination to the eastern side of the landfill
An anamalous condition that exists is a domestic supply well
located approximately 300 feet due south of the landfill remains
uncontaminated (Fig 3) Flow patterns indicate that contamination
would be transported from the landfill south to this area
(Fig 14) One explanation is that a pocket of clay at the southern
end of the landfill area was discovered in the original excavation
for the landfill (lt6) This evidently prevents leachate from
reaching this wells radius of influence
51
Summer Conaitlon
As described earlier during dry months of the year the stream
that normally borders the northern and eastern side of the lanafill
may dry up as far as a point southeast of the E well Tnis
condition existed from the 15 August 1981 to the 27 October 1981
period when streamflow commenced in the northern part of the stream
yet did not overflow the north dam until 17 November 1981 This
created the present day continuous flow condition throughout the
stream These summer conditions were modeled by removing the stream
above the aforementioned location while other conditions remained
the same (Fig 23) Summer condition well water levels listed in the
model generally match field low water table conditions (Fig 9)
Because there is no stream upgradient from the landfill to provide a
stream head and infiltration through the streambed groundwater
runoff from the area north of the lanafill is the controlling flow
input In these moaels an average recharge of 14 inyr was used
which represents a yearly average The summer recnarge conditions
are prooably lower given the effects of decreased rainfall and
increased evapotranspiration during the summer months A domestic
supply well whicn exists northeast of the landfill (Fig 3) nas a
greater potential to be contaminated from the lanafill at tnis time
than when the stream is flowing Flow patterns from the landfill
are such that during an upper stream no-flow condition groundwater
flow patterns are more in an easterly direction than in a
southeasterly direction The stream would act as a source of
infiltrated water upgradient from tne landfill and provide a
52
I ^N gt i I i j i -r- -bull- bullr -T- t- -r- i- TJ JV
bullbullT laquo ^ O - laquo bdquo xi cshy
H r^~ I -~- --^ X- = mdash x^ N
^--^ A bull O^NW -v - gt-bull Ni i I _____mdash - bull laquo l - mdashmdash 1 deg I ^ltv I C
I reg NE A
Js bull vbull A ~ - v T gt- ^ ix - N
-5Z- | N TfS lV I -bull bull iA i gt gt I ^ bullr-Ky L bull 1 _- copy]wgt-- - bull- mdash - - shy
= r Y ~mdash ltmdashA A
^^-lt A _ - - - - bull Hmdash - reg EC x ^-mdash mdash I ---mdash_mdash -t-V-^N - y
I- -bull - r x i X
V ^ 7 I -v (^~~^^r ^^^
sc Emdash-bull vV JI - - - ~ r )N y- -
X - bull r bulllt
^bull^ y y Jlaquo^ - -lt shy
T s^ lt^ ^ +^-b (
X
Legend
landfill limit j-j-bullraquobull excavat ion gt^ -x- s t ream
reg WNWNEECSESC monitoring well locat ions
= == unimproved road fee t
Fig 23 Summer Condition
400
53
constant head across tne northern section of the landfill This
would tend to orient the flow in a more southerly aowngradient
direction In addition the stream which flows adjacent to the
northeastern well could provide a source of infiltrated clean water
to it which would minimize the possible contamination from landfill
leachate
Without Dam
During tne spring scream flow condition the dam failure which
occurred between the 15 March 1982 ana 9 April 1982 monitoring
periods decreased flow to the aauifer and landfill This eliminated
the 5-6 foot head difference over a 19000 ft^ area which had
created a larger area and elevation head for infiltration to occur
The condition without the dam was modeled by reducing the area
encompassed by the dam to a 4 foot wide stream channel thus
reducing the leakance value at that node (Fig 24) The flow change
from the stream to the aduifer between the NW weir and E weir
reduced the model flow loss to 50 gpm Tnis corresponds to the 9
April 1982 monitoring period which indicates a 30 gpm loss
As compared to the previous flow loss in the upper stream
sections to the aauifer the 21 April 1982 and 22 May 1982
measurements between the NW and E weirs indicate a flow gain The
streamflow conditions have changed from an influent
stream-to-aauifer condition to an effluent aduifer-to-stream
condition that increases flow downstream
54
Legend
landfill limit j--i--i- excava t ion x-gtmdash^- stream 400
copy WNWNEECSESC monitoring well locations
= == unimproved road f e e t
Fig 24 Landfill and Excavation without Dam
55
Analysis and Discussion
In order to fully understand flow patterns and Quantify leachate
outflows at the landfill it is necessary to arrive at an estimate
of flow inputs from precipitation ana upgradient sources In the
following analysis it will be demonstrated that the rainfall input
to the landfill is the factor which controls leachate generation A
calculation using the H inyr recharge over the area of the
landfill was made to estimate the leachate outflow due to rainfall
infiltration An estimated 134 gpm is generated from the entire
landfill area Simulation of the existing conditions (Fig 24)
indicates a groundwater divide in the landfill is located
approximately at the western third Therefore approximately 23 of
the generated leachate flows to the eastern side of the landfill or
9 gpm The effect of the flow input from the upgradient stream is
evident when tne summer condition witnout the stream is viewed
(Fig 23) Without the stream to infiltrate the landfill and the
recharge and northern boundary condition as the flow inputs the
head at the northern end of the landfill drops about 5 feet from its
previous value A flow pattern from the north central part of the
landfill to the eastern side indicates a 12 feet head difference
with recharge - but with the upgradient stream a 16 foot head
difference occurs Considering the transmissivity change the
stream would increase the leacnate outflow from the landfill
approximately 43 under a low water table stream influent condition
to the aauifer This would increase leachate outflow to the east
side to approximately 129 gpm This value approximates the
56
outflow at the SE weir location during the summer monitoring period
when the upper stream was not flowing (Table 3) The outflow from
the western third of the landfill whicn lies to the west of the
ground-water divide would be approximately 63 gpm
Realizing the importance of infiltration to tne landfill as a
major influence on the generation of leachate an analysis of this
w i ll be discussed An estimate of infiltration was made using the
precipitation recora for October ana November (Appendix A) During
this time period a minimum of direct evaporation ana
evapotranspiration occured and the grouna is not yet frozen The
top cover over the lanafill is generally 05 ft to 2 ft of local
sandy soil and subsoil availability determined what was used The
top of the landfill is at an elevation of 92 ft as compared to the
ground surface at well W which is at an elevation of 76 ft
(Fig 25) This compares to the well W water level which is at an
elevation of approximately 52 ft This creates a long path for
infiltration through the unsaturated zone The topcover generally
slopes eastwara at a grade of 2-5 The west side maintains a
relatively steep slope of 10-15 ft drop within 50 ft ana the north
and eastern slopes have a more gentle slope of approximately 10 ft
within 100 ft distance An unlined surface arainage swale channels
surface runoff from the northern section of the landfill past the
NE well to the eastern side ana low area in the vicinity of the E
well This has a drainage swale to an area near the stream but
doesnt directly connect to tne stream A poorly graaed drainage
swale exists on the landfills left side The landfill material has
57
excavation
seepage observation ^
hole
Legend bullmdash landfill limit -^--excavation limit r^s- stream
copy WNWNEECSeSCSEN monitoring well locations
--- unimproved road O location of amp Inf i l t rometers O
feet
Fig 25 Infi ltrometer Locat ion and Drainage Feature
58
been placed in 10-12 ft cells and covered with 1 ft of soil at the
end of each day The material has settled differentially creating
areas for depression storage
An estimate of the percentage of precipitation that infiltrates
the landfill was made from precipitation records recorded well
elevations and an estimated specific yield for the landfill
material The volume of water that infiltrated should eaual tne
specific yield multiplied by the well water level rise Several
recharge periods were studied using this relationship Once the
percentage of precipitation that has infiltrated is determined the
percentage that is translated into runoff is simply the remaining
percentage if evaporation is neglected
From the literature for a slightly inclined slope of 2-5
typical runoff coefficients range from 10-20 in either sandy or
heavy soil (16) The landfill cover is generally sloping to the
east which creates a long path (approximately 400 ft) before the
runoff reaches the steeper slope on the eastern side of the landfill
of 15-20 The long drainage distance creates a greater time for
rainfall to infiltrate Another consideration is the actual
capacity of the soil to conauct water into the soil which was tested
in the field using double ring infiltrometers An average initial
percolation of 8 mmhr the first hour and a subseauent rate of b
mmhr occurred (Fig 26) The 8 mmhr rate compares well with
other sandy soil infiltration rates (14) Therefore if the
intensity of the rainfall exceeded a 5 mmhr rate for several hours
59
CO + 09 o
E o
CO
o Z pound C
O
C9
o DC
CO
CD CM
ogt CO N- to -4 CO CM
jq tuu i U O | raquo B J J | | J U |
60
on a poorly drained surface the additional rainfall would be
translated into runoff because the soils infiltration capacity had
been exceeded
The initial 8 mmhr infiltration rate was due to the pore spaces
in the sandy soil being filled and the subsequent 5 mmhr rate was
percolation into the low permeability landfill material The tests
were conducted in November assuming a minimal evapotranspiration
and the field capacity of the sandy soil had been maintainea
The W well was used as representative of the water elevation
changes in the landfill because it is directly adjacent to the
landfill 900 ft distant from the upgradient stream This minimizes
the effect of infiltration from the stream and maintains a high
contaminant level During periods of high runoff conditions excess
surface water ponded in a poorly graded drainage swale on the west
side and directly adjacent to the landfill This influenced the W
well at a time the contamination level dropped (Fig 11) Before
this occurence in mid-December the rise of the W well closely
matches that of the SC well and a background well SK6 which is
located outside the study area (Fig 7) Therefore it was analyzed
as a valia indication of the water level rise during the mid-October
to mid-December period The monitoring of the SC well was
intermittent due to inaccessaoility because of 10 ft extensions
being placed on the well as the refuse was being filled in arouna it
61
A high rainfall period from 14 November 1981 to 1 December 1981
was chosen for the initial study period The effects of
evapotranspiration were neglected due to the cool temperatures
experienced at this time Therefore it was assumed that the field
capacity haa been reachea and tnat any additional input to tne
unsaturated zone would result in direct percolation to tne saturated
zone During the time period 14 November 1981 to 22 November 1981
029 ft of rainfall fell and the well W rose from 488 ft to 493
ft - a 05 ft increase During the next 8 day period there was no
precipitation yet the W well continued to rise to 4972 - a 042 ft
increase The slow percolation of water through the landfill
material would account for the latent rise in the well water level
From previous reports a specific yield for refuse was estimated to
be 028 (1920) This value is dependent on the original compaction
of tne material age and resulting consolidation
During the 14 November 1981 to 1 December 1981 period 029 ft
of rain fell and the well increased 092 ft The following
relationship is used to evaluate the infiltration value and runoff
I = (Sy) h
Sy = specific yield
h = well rise
I = volume infiltrated
I = (028) (092 ft) = 0261 ft
62
The difference between the precipitation and the infiltration is
the runoff (assuming no evapotranspiration) Therefore 029 - 026 =
003 and furthermore 003029 - 13 runoff This corresponds in
the literature to a typical runoff coefficient for an inclined
surface of 2-5
Analyzing a longer precipitation period from 18 October 1981 to
1 December 1981 a net precipitation of 043 ft (accounts for
evaporation) occurred less 10 for runoff or 039 ft infiltrated
This results in a 139 ft elevation increase The well water level
actually increased 132 ft shy only a 5 deviation from the
calculated
From tnis investigation it is seen that a large proportion of
the precipitation has the potential to be transmitted into the
landfills saturated zone Exceptions are wnen heavy precipitation
periods exceed the soil percolation capacity frozen ground prevents
infiltration and direct evaporation and evapotranspiration recycles
the ponded surface water and infiltrated soil moisture back to the
atmosphere In retrospect water temperatures within the monitoring
wells could have been measured to indicate thermal effects from the
landfill on ground-water temperature Ground-water temperatures
were assumed to be 50deg F (9)
63
Specific conductance measurements serve as an indication of
contamination levels These measurements are used to trace leachate
movement which represents ground-water flow patterns Factors which
must be considered when monitoring pollutants are the attenuation of
the leachate contaminants which occurs both in the zone of aeration
and the saturated zone The former is a more complete process
Dilution dispersion and cation exchange are the primary factors
involved in decreasing leachate concentration in the saturated
zone The glacial outwash materials of southern Rhode Island do not
have a cation exchange capacity or a high buffering capacity so
attenuation is simply by dilution and dispersion (22)
The NW well consistently exhibits relatively low specific
conductance levels even though it is in landfill material It is
situated in a drainage swale and ground water elevations range from
543 to 5944 This is several feet below the upgradient stream
elevation of 64 feet which is less than 400 feet away The bottom
of the wellpoint is at an elevation of 5312 feet well into the
landfill material Infiltration from the stream to the landfill has
occurred at this location
The W well is situated on a bedrock high adjacent to the
landfill approximately 900 feet from the upgradient stream and its
water level is higher in elevation than the excavated pit (West
Observation Hole) which is 300 feet directly west The W well
maintains a contaminated level A poorly graded drainage swale to
the west of the landfill provides areas for extensive ponding and
infiltration to occur which explains the drop in conductance after
a high runoff period
64
The SC well is located in landfill material and has a
conductance of over 8000 umhos This indicates that leachate is
undiluted The oottom of the wellpoint is at an elevation of 389
feet which is situated in the landfill material
High specific conductance measurements in the west observation
hole and well W and their relative elevations indicate a
west-southwesterly flow direction from the landfill Infiltration
recharge and leakance from the stream into the landfill provides the
necessary elevation to cause outflow in this direction
Contamination from the landfill to the surrounding streams is
evident (Table 4) During the period 15 August 1981 to 27 Octooer
1981 there was no flow in the stream that Borders the northern and
eastern side of the landfill until a point just south of the E well
was reached High specific conductance levels in the EC and NE
wells were recorded (1000 jjmnos) At a point directly east of well
EC a pool of water existed that was relatively uncontaminated which
is designated as the East Stream] location (Fig 10) At a point
just south of that (East Stream^ polluted water in the streambed
was flowing at a low rate This was measured at the SE weir
location and which had a high conductance also Flowrates varied
between 6 and 23 gpm and specific conductances were over 350
pmhos This low water table condition flowrate is the baseflow from
the eastern side of the landfill and indicates a southeasterly flow
direction from it
Streamflow commenced in tne northern part of the stream 21
October 1931 and the north dam oegan to f i l l Stream specific
65
conductances were low indicating a clean water source Tnis
continued until 17 November 1981 when the dam overflowed ana flow
throughout the east stream began A weir was placed at the Rose
Hill Road NW location and was compared to flowrates at the SE
location Flowrates decreased and specific conductances increased
between these two locations
To further investigate the condition of a lower flowrate
downstream than upstream an intermediate weir was placed at the E
weir location (Fig 9) This snowed tnat the stream from the M
weir to the E weir was losing water to the aauifer (influent
condition) and gaining water at the SE weir (effluent condition)
The condition of a net loss of water between the NW and SE weirs
remained until 19 December 1981 when a snowmelt rain condition
caused increased surface runoff and a net increase in flow at the SE
location Upon analyzing the March and April 1982 streamflow
conditions the expected case of a net ground-water pickup from the
E to SE weir continued The explanation for tne initial net loss of
ground-water is the fact that the leakance from the upstream section
was being discharged into aauifer storage to raise the ground-water
table to an eduilibrium level Upon reaching a high recharge
equilibrium steady state condition any additional input will
eventually be transmitted as baseflow out of the landfill and a
downstream net pickup will occur A hign water table condition
prevailed during the January through May period maintaining this
condition In April the north dam broke through reducing the head
in that area by 4-6 feet The 9 April 1982 monitoring revealed that
66
an influent condition remained between the NW and E weirs but at a
reduced rate The 21 April lower stream flow condition shows a
small pickup of water between the NW and E weirs indicating the nigh
water table and low stream flow conaitions combined with the absence
of the dam had changed the conditions to an effluent condition
This was evident in the May monitoring period
Evidence of contamination on both the western and eastern sides
of the landfill supports the existence of a ground-water divide in
the landfill The west stream which drains the excavated area to
the west of Rose Hill Road shows contamination pickup between its
northern section and the SW weir The W well and ooservation hole
indicate high contamination levels which reinforces the concept of a
contaminant outflow to tne west excavation stream
As shown previously flow towara the eastern side of the
landfill is evident from the nign specific conductances and specific
conductances increases in the stream This is especially evident
during low flow conditions when the stream starts at a point to the
east of the landfill and flows with high specific conductance levels
From the literature a relationship between specific conductance
and dissolved solids exists the dissolved solids (mg1) are
approximately equal to the specific conductance times a factor
ranging between 55 and 09 (39) in this case it is taken as
065 (41) The dissolved solids increase coupled with the stream
flow increases provides a basis of calculating the dissolved solids
outflow to tne stream This calculation method was used in a
previous study (26)
67
The relationship
=Cinout Coutflow Qoutflow - Cupstream Qupstream Qinput
where the numerator is the streamflow pickup and the C- and
Q-jnput is the concentration and flow input from the ground-water
This can be used to estimate dilution level outflows from the
landfill Initially this is used for the ambient ground-water
pickup between the E weir and the SE weir This entire flow doesnt
come from tne lanafill but much of it is conaucted in the high
transmissivity area between the lanafill and stream from upstream
leaxage ana surficial recharge Tnis is evident when this section
of the flow pattern is analyzed on Fig 22 Therefore the landfill
outflow is mixed with tne ambient groundwater flow which dilutes the
landfill leachate before it enters the stream To illustrate-this
concept a calculation using the 9 December 1981 monitoring is used
At this time a flow of 672 gpm occurred at the SE weir with a
specific conductance increase of 7 ymhos between the E and SE
weirs The dissolved solids increase would be approximately 795
Today in tne stream
Where
Co = 90 jumho at SE weir
Qo = 672 gpm at SE weir
Cus = 83 jumho at E weir
Qus = 606 gpm at E weir
Qinput = 66 gpm gain
Cinput = 154 jumho
68
The 154 jumho value represents the contaminant level in the
ground-water adjacent to the landfill
This relationship is applied to approximate the concentration
level dilution in the ambient ground-water between the landfill and
stream The aforementioned relationsnip is in turn applied to the
landfill outflow into the ambient ground-water flow adjacent to the
landfill The ground-water receives landfill leachate dilutes it
and then transmits it to the stream The previously calculated
value of 129 gpm was used as the outflow from the landfill
Co 154 jumho flows into stream
Qo = 67 gpm flow into stream
Cus = 83 jumho background level
Qus = 67 gpm - 129 gpm = 541 gpm
Qinput = 129 gpm from landfill
Cinput = 451 jumhos
Approximately tne same contaminant levels from the landfill (tbl
umho) are arrived at as existed in the summer streamflow conditions
when the upgradient ground-water flow adjacent to the landfill was
at a minimum
In addition to using specific conductance to define
contamination zones electrical resistivity can be used to indicate
contaminated areas The measured earth resistivity is inversely
proportional to the conductivity of ground-water Water containing
contaminants with high ionic concentrations are more electrically
conductive and will have lower resistivity values than surrounding
natural ground water Therefore resistivity methods can be used to
69
delineate plumes of contaminated ground-water that have hign
specific conductances This has been demonstrated by several
investigations (11122328374045)
In this study a Schlumberger vertical electrical sounding R-l
was made in an area of known contamination at the W well (Fig 12)
Given the geologic constraints provided by the well boring log a 4
layer computer model was used to match field survey values A
Schlumberger sounding R-2 in an uncontaminated area north of the
landfill in the same geologic setting was used to provide a
comparison background sounding (Fig 12) A seismic survey N-4 was
made to obtain water table depth and depth to bedrock as input
parameters to a four layer resistivity model (Fig 8) Tne results
of the electrical soundings have been tabulated in Table 6 and
plotted in Fig 27 and 28 respectively
The ascending portion of the field Schlumberger curves were
initially matched using a two-layer ascending type master curve to
provide an approximate depth and apparent resistivity of the
overburdened topsoil layer (8) Tne second unsaturated layers
apparent resistivity was determined by using the graphical
interpretation of total transverse resistance The total transverse
resistance is approximately eoual to the peak value of the curve
times the corresponding Ab2 distance it occurred at This in turn
is eaual to the sum of the first two layers apparent resistivity
times their corresponding layer depths
70
bullH
OJ bull bullH 4J CO CM
c ce G bullrH
j-gt ca c c a 3 ltu O L
co CO 0
bullo Q bull laquos c n 3 -U OrH f~ 3 bO ltn y CO O cc CO ^mdashN
QQ bull
bO bOJJ C C Ci_i
O l T i O O O O O O O O O O O O O O O O bullH bullH mdash^ bullo 0 C c3 f| 3 O raquo O CO CQ
CO
rH
CO O
L 4J
^ltU
i- 1 ^n ^b O 4-) bull2 CM bullH C OJ 1 -U bullH CO C L O a ^-^ 0) a
rH c a L CD ltu (1) 3 tlt bO cO I
3 a 0) a Q 4J laquoa e CO 3 (H bO c C O bullH
CO TJ C 3 bull
bull O bO -i-3
0 CO C O3- O G O O O O O O O O O O O O O O O O O O ft rt1 -raquo - t l S^ ft tfigt f I mdash^ K_ l_ raquo mdash I gt fgt I l 1
(1) 0 rH CO CJ JD o^^ CO CO CQH lts
71
Legend
A actual field measurement
-e- interpretat ion
10000 bull
6000 bull 5000
4000-
3000shy
pound2000| ltD
_ r 1000
09
5 600 pound 500 - 400
I 300 a a lt 200
100 10
Fig 27
20 30 4050 100
Distance AB2
Schlumberger Sounding
200
feet
R-1
400 600
72
loooot
6000 5000 4000
3000+
laquo2000 e
r 1000
raquo 600 pound 600 ~ 400
$ 300 a a lt 200
100
Legend
A actual field measurement
-Qmdashinterpretation
10 20 30 40 50 100 200 400 600 Distance AB2 feet
Fig 28 Schlumberger Sounding R-2
73
Formula T = f
Background Sounding (9000)(15) = (3110j (1 7) + gt2(8)
= 16214 n- ft
W Wel l Sounding (b200)(60) = (500) (2) + pound2(28)
= 13250 SL- ft
To determine a resistivityp3 value for the third layer a
graphical interpretation for the longitudinal conductance S was
used(48) This is eaual to the sum of each individual layers depth
divided by their apparent resistivity
Formula S = -r1 +~r-raquobull-ra
Background Sounding 0017 = yyg + ~^
= IbOU - ft
W Well Sounding 0285 raquo -ggg 7^3 J~
= 179 v-ft
These values were input to a program which calculates a
schlumberger sounding curve (47) The theoretical sounding curves
approximately match the field curve as viewed on fig 27 and fig
28 To provide a check on the apparent resistivity of the saturated
layer at the W well the following relationship was applied 1OOOO
= spec-jfic conductance (umhos)
74
At the W well the specific conductance was measured to be 3 00
jmhos at approximately 10degC
Assuming a formation factor of 45 for the glacial outwash (23)
material Archies law is applied to estimate an apparent resistivity
of the third layer (7)
fgt FF x p
A= 45 x 103-n-ft
A= 4G3 JL-ft
This is a reasonable approximation to tne 3i= 179^-ft calculated
analytically from the sounding curve interpretation
75
Remedial Measures
With the analysis of f low patterns and contamination zones
recommendations to minimize the environmental impact of the leachate
can be reviewed The basic technique is to minimize all sources of
water reaching the refuse so that leacnate production is minimized
The oiversion of precipitation by a relatively impermeable cover and
proper channeling of runoff would minimize percolation into landfill
material Caps and seals can be constructed of clays fly ash
soils soil-cement lime stabilized soil memorane liners
bituminous concrete and asphalttar materials (15) Proper
contouring and grading will help minimize infiltration If a soil
cover is used a vegetative cover can be planted which will utilize
some of the infiltrating flow through evapotranspiration losses
during the growing season By minimizing the length of slopes and
providing proper drainage channels tne surface runoff can be
conveyed to a downgradient area outside the recharge zone
Therefore this surface water will not increase leachate production
from the landfill Also by increasing the slope of the cover over
the landfill itself a higher percentage of runoff and lower
infiltration will occur
To minimize upgradient ground-water influx to the landfill an
impermeable subsurface barrier or intercepting trench could be
used Barriers can be made of bentonite slurry-trench cutoff walls
grout curtains or sheet piling cutoff wal ls extending to the bedrocic
or an impervious layer to effectively prevent water passage or
create a head loss that wil l lower the water table In addition an
76
intercepting trench which has a perforated drain at tne lowest part
of the water seepage zone could be used to intercept and divert the
entire flow
These possibilities have been evaluated with the help of the
model to determine workable solutions for this landfill The
primary concern is to eliminate leachate flows to domestic wells
Initially a simulation was run that eliminated recharge over tne
landfill area (Fig 29) This had a considerable effect on the
ground-water flow patterns of the landfill area The mounding that
had previously occurred under normal recharge conditions was
eliminated and a general drop in the water taole within the landfill
of 2-3 ft occurred The effect of eliminating recnarge over the
landfill when the upper stream is running would cause greater
infiltration from the stream as evidenced by only a 2 ft head loss
in the landfills flow conditions This is evident when comparing
Fig 29 with Fig 24 Tnis indicates that this measure would only
marginally reduce the resultant leachate flow from the landfill
material that lies below the water table In another situation
where there is not such a strong potential for upgradient flow this
measure has proven quite effective (6) In this case the landfill
cover consisted of four layers an intermediate sand and gravel
cover immediately above tne regraded waste materials a 4 inch sana
bed designed to protect the overlying membrane a ilO mil flexible
PVC membrane and an 18 inch final cover of sand and gravel
77
Legend
landfill limit -raquo- -^ -raquobull excava t ion x-^x- s t ream
400 copy WNWNEECSESC monitoring well locations
= -= unimproved road fee t
Fig 29 No Recharge over Landfill
78
Controls such as 10-30 mil polyvinyl chloride covers favor the
development of an anaerobic environment which increases waste
decomposition time and would necessitate installation of gas vents
at several locations on the landfill cover Tne integrity of tne
synthetic cap may be further threatened by subsidence which create
differential stresses on liners Settlement would create areas for
ponding and depression storage and eventually necessitate regrading
the landfill surface The landfills south-central area has oeen
filled within the last year and will prooably need to be regraded
due to settlement within the next few years
Another possibility for a liner would be a soil-bentonite
cover A layered cover consisting of natural materials with low
permeabilities such as bentonite clay followed by a layer of highly
permeable material such as sand and finally a layer of topsoil can
be used Due to potential drying out and cracking of the clay liner
a synthetic liner is the preferred method
The most immediate technique is to grade contour and vegetate
the landfill cover which has been done at this site Althougn an
impermeable cover would probaoly reduce the amount of leachate
produced it would not eliminate the upgradient flow and provide
guaranteed protection of wells in the vicinity of the landfills
northwestern section
A slurry trench along the northwestern perimeter of the landfill
would effectively cutoff upgradient infiltration and divert recharge
infiltration in a southeasterly direction thus removing possible
leachate outflows from the radius of influence of the neighooring
79
wells This has been simulated using the computer moael ana flow
patterns as shown in Fig 30 Contour lines are distorted in the
vicinity of the slurry trench due to the 200 ft nodal spacing
Transmissivity values of 1 ftday were input at the slurry
locations to simulate an impermeable barrier Tne surface recharge
at those nodes does not infiltrate the relatively impermeable grid
nodes at the slurry locations and flows to the edge of the noae
thus creating a dramatic head loss within a short spacing To
effectively simulate this a variable grid spacing should be used
with reduced node grid spacing at trench locations to eliminate
distortion The computer simulation shows that the slurry trench
could direct flow in the landfill area in a southeasterly direction
and away from endangered wells In addition it would reduce
upgradient infiltration from the stream into the landfill This
measure would prevent leachate from spreading beyond this carrier to
possibly contaminate neighboring wells
The combination of both the slurry wall and impermeable cover
would be ideal measures to minimize generation of leachate and to
stop its spread to neighboring wells The slurry wall without
recharge over it or the landfill is simulated in Fig 31 This
indicates a lower water table tnan eliminating the recharge to the
landfill The slurry wall has blocked upgradient ground-water flow
at its location to the landfill
80
Legend
landfill limit -laquo- j -laquobull excava t ion ^^- stream
copy WNWNEECSESC monitoring well locations
= = = unimproved road ssi slurry wall
f e e t
Fig 30 Slurry Wall
81
Legend
landfill limit j- j- J- excavat ion x-v^gt- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road s==s slurry wall
400
feet
Fig 31 Slurry Wall without Recharge Over It or Landfill
82
An intercepting drainage trench is considered next If a trench
was excavated to a 30 ft depth in the outwash material extensive
shoring would be required In addition difficulties would arise
when the trench was excavated below the waterline Tne trench would
be sloped to provide drainage and backfilled with a highly pervious
material to intercept and divert leacnate locally a conouit which
is perforated on the top to allow infiltration and unperforated on
its lower perimeter to permit continuous drainage to the collection
treatment center would be installed on the bottom of the graded
trench The difficulties involved in excavating below the water
table ano shoring the sidewalls to permit implacement of a drainage
conduit at a 30 foot depth make this option increasingly infeasible
83
Conclusions and Recommendations
The location of the South Kingstown landfill in permeable sand
and gravel glacial outwash material (107 ftday) combined with the
high hydraulic gradient across the landfill area (20 ft1600 ft)
creates a high potential for ground-water contamination to occur
This is intensified because refuse nas been placed below the water
table The low hydraulic conductivity of the compacted refuse (1
ftday) and the excavated area to the west of Rose Hill Road have
both contributed to modifying the original southeasterly flow
pattern These modifications have created a ground-water divide in
the landfill at approximately the western third section Tnis
results in approximately 13 of the leachate flow from the landfill
or 63 gpm flowing in a southwesterly direction and 23 or 129
gpm flows in a southeasterly direction Infiltration from
precipitation recnarge over the landfill (up to 9Upound) and from tne
upgradient stream during low water-table periods provides tne
necessary influx into the landfill Evidence of contamination is
clearly seen on both the east and west sides of the landfill which
reinforces the previously stated flow patterns
Of the several remedial measures reviewed the contouring and
grading of the landfill topcover and drainage swale provides the
most immediate protection The topcover has been graded mulched
and seeded to provide a low runoff slope generally to the east
The drainage swale on the left side of the landfill has improperly
graded sections which should be corrected Its northern section
could be drained into the northern sections swale and the southern
84
section drained to the southeastern section of the landfill Tne
point of the drainage swale which divides the northern drainage
swale from the southern one should be determined by a field survey
Cost is a major contributing factor when determining which
remedial measure is to be applied to the given situation For the
purpose of this report cost estimates are not presented but rather
the effectiveness and feasibility of the remedial measures are tne
primary considerations As was reviewed and simulated in the
computer models the slurry trench and impermeable cover over the
landfill are two viable options that would effectively provide
protection to the domestic supply wells in tne vicinity The
impermeable cover would eliminate precipitation recharge into tne
landfill yet drop the water table only a few feet due to upgradient
infiltration from the stream This would decrease the hydraulic
gradient thus diminishing the potential for a contaminant outflow to
surrounding wells The supply well of primary concern is one to the
west of Rose Hi l l Road marked well D on Fig 2 If contamination
occurs in this well the most effective measure would be to block
off leachate flow in this direction by installing a bentonite slurry
trench at the location indicated previously This would effectively
prevent leachate flow in the westerly direction and diverts it to a
more southeasterly direction In addition the slurry trench
precludes infiltration flow into the landfill from the upgradient
stream
85
Tnis report has effectively reviewed tne original ana existing
flow conditions and contaminant levels in the vicinity of the Rose
Hill landfill The purpose was to provide an understanding of
ground-water contamination patterns and study possiole remedial
measures
86lt
Appendix A
Precipitation Records
Monthly normal precipitation 1941 -197O
i$l Total monthly precipitation
KINGSTON RI
14
ia
^JO T I bullbullL
pound 111 laquobull
4
a
n
-
^
-
-
KS1JAN
^Ii R3 HB MAR
1
1 APR MAY
1
1 JUN
1981
JUL
-bullraquolaquo H
AUO SEP
K3~~f$s bull
_imdash
i1S 1
OCf NOV OtC
171 1 iI1
JAN HB MAR APR MAY
198
Fig 32 Precipitation Record
- - - -
IM 1 MtvJrflgtlgt c ortli-A t lUN I r nraquo rl - -
gt|MO CLIMATOLOQICAL OUSERV ATIONshyr-r bull JK gt raquo - 1
i5fWA I VAPOR Al IOH -bull AIM If MPCRATUM bullF 0 riccipn AT ION UNO IlMf
bull 14 H 14 H mdash Vshy ADDITIONAL DATA IfUAlUS OATt 1 bull raquof bull bull 1 ta
14 Hw rlaquo4 w bullbull bull 1 114 1mdash4 (llrl 1 1 1fl Hll
0 kmdash
Mraquo M4 raquo i T i 4 bullraquo-laquobull i i
Lgt f 1 21 S 1 Hbull - - bullbull -
ltJL 1 2 01 - - _ _ 1
mdash
-
1 12 _ Q I
mdash shy
mdash 4 (C ( - - fVi 1 - 0
1 (1
^ 1
Vvraquolaquo IJ1^ raquo CP O 3L 1 Z - i bull j-t-J
1 J
LH Vb T n 0
1 gt fl oo O ~l 2 L - bull 1 P )laquo jn iP IP - OOI L5L mdash shy
-t 84 ^(^^ ^fi P i flja 0 JO II 10 tl tcgt 7 J IV wllaquo
h l2L bull 0 lt -_ shy
-id VJ lt 3C 2 ft OOL -mdash
U 71 C1 Sr 2 13 2 nl JLJraquopound HP r M ltf1- (
IMe 2 ii O It
n jlt dl 1 1 bull o o-il ST i 1 i 25 2-x-1
-
ri
i tlL O mdash gtbull bullgtlt 1ft -o- is Oil So iJK 2-io otv u 31 fil loi 2 il Oll it Of wr is i1raquo -iZ 1 deg|0 01
M IT So - mdash
- 13 1 CT mdash i - mdash 21
shy
Tl Ci av ZUll IMT 0 IM Pe v _ 1) T) S) ii3( dlt Ii 2 lt^2 II li- S1 riivi To 7HX lt3lO 14 ^2- iTi I li 011 -- - -i -^IS no 5^ or i | T Jift laquoV OoH bullla It Va iCO mdash L OIL 11 bullvf poundgtpound lS_ flv oh P-lfe 1 poif _ shy11 IB kl (4 itlaquoT lamp llt0 oot^
mdash -n
It T1 |ir( L1 HI 2 0 oil
U 1M ft go C ICf^ -^2 Z laquo-|o
11 it 5 bulln - TO o abull Li u-i IT1 -- Iw O ltM (I bullbull bdquo-I(K 1mdash -tilltLlA ttfe
i Dgt ac -- U 44 4 11 1 1- ytd i i_i J-K 0 i if -i i i V t Wl raquoOHM 1-1 US D C P A R T M f N T OF COMMfRCE t 4 1 IUII 1 1 ^~) mdash
llaquo- Hi NC bull bullh bull bullJL^V HBl CO 00
11
)jLsVyr^gturv
^ | TKu
|-_t_ bull(
IIMgt I I Mt|UU III- II 11
PNECIPITATIOH
I 1 1 IMX
IMO
bull llfclaquo I UCIUKI) Ur C V A r U M A AHO CLIMATOUOCICAL OBitH
E V A F O R A T I C r i Jttffl laquo amp hMIlaquoJllaquoJIIlaquoBgt
DATE AOOITIOMAL DAIAKMAKk M
bullraquobullmdashlaquo
tp 01 (1 Of Ll OOI ooo
0^1 o-i 10 tl |00 102
OC (1 13 Ofl
it i rc DS os an
(1 SV o
Ul 010
(ISl 101 I on
130
II 5= Otl
ss lt 001 (IK Ml
jt il HIT
7 it
ow Wo 17 Top 2-01 OIO
(0 oov zi oot
u CO ^A 0 to Zoi CLflS
bull50 01 ljtj
nshy 5H LO OIt
50121 IVO QJO
14 Co Ho LO Hl ^pound Jl 1
ltM ool fllc
H Tl 01 II
11 11 Q1
iH OIO
HO 2 llaquol 11 II
lifc
IV-IIM ul OIPAITHINT or COHMIICC NOAA
NAtlOHAL gtIATnlaquoll raquotraquoVlClaquo CD
r~
All TCUMMATUNI ^V UII rgt ITmi 1 Cwphu Obic i gtn t ngir-H 30
rilCiriTATIOH
JJ T I rTJ-rimdashr-iramj|MP CLmATOLOQ
laquolaquo jftilCiii bullIHO
Oi1l ADOITIOHAL DAIAlllu
Ilf4ft
Sii1
(1 2 IO OO
Hl ii SO
us OIM
Q^L
a A3 Hi SZ Sf^ bull 12J2
HI Z-SF OOl 1C t HM IA H ICP fiJA
OOl 10 (310 sn 310
if HI (0 ^01
bullit SO 28H poundJ1 11 006
14 35 TX oon II (bull2 it zr II c-S
rr Zll lo 31 OP an 31 a 31 oor
CSW O-ll Si CC Of 011
Oll _ I |ft
00
u i oerraquolaquoTMiMr of c NOAA
NATIONAL K C A T N C M SCMVlCC
TC^S lk)oiVroTJA
TETT I 7X
1raquolaquolaquo 4 bdquo ir lt er ni I^OV ltqgl j--^ TQ
MICiriTAllOH ITIND
D|mdash
b5NO ctiUATOtoiCAL oeit^
OATI AOOITIOMAL OATAVlHAtt
0-tt
Mlaquoh bullbullbull- rshy laquo
I- ltltriu HI I 4 bulllaquobullbull1
Zii
30 Dfellt otvt
at HA
OOI
62
iJ_S2 HI if
bull- 20 SI 2i So
So
VVfr
OSfc
I (
Jtlt
3aoi
r j -bull ie MA
Irill iiol
in^ 14
Mo
Zll
214
21 1P
00-i
bulliron
17
bullr
11 i ir- I J Ktf^c
US D E P A R T M E N T OF COuMEDCC I | C gt A A
K AIlaquo Ttupf lATuit r
|SlVi AlJ PIICIPITATION
oJud (El
VIM i Uraquo
MIND E
EVAPORATIOH flnrft bull A ftufiifccdll
KECORO OF eVAPllHAtlil bull I CLIHATOLOOCAL OBSERVA ^Hij
14 MM A_M AOOIIIONAL DATA11 MAIM
Mr bullH Oo|
M Si lift
bull221 IHI
ZS Ji 40 IZV
icr KS I
HZ 111
bullT 21
loA UK JA IP
v^ ft
1M 2Sshy IT Tl
71 V |
i I 31 1deg a
uty^ U bull3
ons 1 CiO TxX
HHO (10
3H 19 12 10 IP
raquo3H raquo | 5t io
OP OIT
14
vO UI Of PANTMINI Or COMMCRCf MM O A A
F ngt TIHH
iiicffwiffc 4 rJ (TIM bull Cempltit Obitittiio
AIlaquo TIMHIATUM PHICinTATION I V A f OK ATlPrl
OATI ADDITIONAL DATA KMAlIt
U4laquo4 +
03H Ji
10
rc a 1 16 oi ii
tiiy 10
OI
II i23 or o 13 -y~ou HO
II 3V III i 3 t
V laquop oot
OM1 SS ne
T an -i IP
Olt zr LTV
3T 001
a -11 2T
10 an 31
-1 raquo 131 UP 3H lf 14 Lpoundshy
it 14 30
IS
Ui O I P A K T M f H T OP COWlf ICfM O A A
NATJONAI V C A T M C n f t K M V l C K
bullbullbullbullbullshy -2 o AIlaquo TIMMRATUM f fKICIPITATIOH
OATI poundt- MMINMAL DATAk
ZP 51 lo icr
011 111
OoT IHf
Ut 003 am
3o 13 ao
4A X 05shy
H4 i IjJyiV131 ooc js
IH oi 01 tL 18 13 a
No 11-7
rivgtp OO| M Hi 03 01
It 12
bull I 41 bull7119 14 ^^ raquo 31 15 lampk n M ho i
Jo -j-
-J
I
Ml H^ I _
amp2ampUi^= LS 0 S 0-f bullTTT
-Vmdash gt U_ bull 1 rOHM I- 11 OI OCPARTMlNT OF COMM(NCC
HO NATIONAL W f A T M f H ftfraquoVlCI
98
Appendix B
Boring Logs
99
X iHECT 1 ff 2
OAT American Drilling amp Bor ini I Co Inc
wo WATH smn EAST PR ov IDENC E ft 1 Town of South Kingstown South K ngstown R I MOLENO X-J
TC 100 RCSS bull ujrMonitorinq Well Installation | South Kinqjtown R I UNC a STA Pf KXICCTHJ LOC ATK3N
bull cfrserrr TO above S MPLES S FNTTO _ _ |laquolaquor A-109 SURF ELEV RE PORTSEr
GROUND WATER O6SE RVATC MS 1 CDREraquolaquo m-T nn75 laquo A 256 - 20 mdash Hew y
Instolled 32ofT-l2 PV C - JO- COMPUTE 111275 K toia 3- I-WI 1-38 TOTAL MRS bdquo10 screen BORING FCACUAM J K lanq MAI rraquo HomnwWI 300 140 IampPCCrc Mamlaquor Fall 24 30 lampaaiona SOLS ENGR
LOCATION OF BORING H ONITOKING WELL
Coung Samplt Tjp Blow per 6 Manure SOU IDENTIFICATION Strata SAMPLE ^^^yV Bloot
foot
Otptni
From- To
el
l
on Sampler
0-6 1 -6-13 12-18
Dentity or
Conmt j
Chang Remark include colo^ graaation Type of tod lie Rao-coMr type condition nordshynetiDntotf time leamt and tie No Pen Rtlt
2 No top sample 5 12
1 loamy fine sand
bull)^ 40 30 36
5- 616 0 23 20 16
noist iense
Brown fine to coarse SAND some fine to coarse gravel Trace silt
^
1 18 18
36 8-0shy57 40 30 V 35
|0-||-6 D 14 24 20 Srown medium to coarse SAND Some fine gravel cobbles
7 IRshy 16
27 75 37 3
IS- I- D 5 14 16 3bull
ISshy 15
42 50 I9--0shy50 65 20-2ll-6 D 9 23 26 bull Jrown fine to coarse SAND Tbullwshy 1Z 75 90
22-0 Trace silt trace fine gravel
124 120 74 60 52 41
7S-ltlaquoil-A DX 71 16 13 wet very dense
Gray-brown fine to coarse SANC Some fine to coarse gravel little silt
H IR u
40 30--0
3C-30-IO
3l4-334
334-3314
38 4-434
D
c
C
C
7 IflO
94 6
we tr j
y se
ft irox
30MOshy
31 -4shy
Gray-brown fine to coarse SAND Trace silt
Gray-brown fine SAND some lilt trace fine gravel
Too of Rock 31 -4shy
Gray-pink GRANITE
6 7
amp
CJ
IltJ A
60
601
IQ mdash
2(
4
5 i Hard
ft 5ome seams bull
GROUND SURFACE TO J 4 U3CD_ ^JVrf bullbull( tutu t to 4o 4 SampM Type Proportion UMd MOB Wtx 3 OfaM on 2OD Sampler SUMMARY-
OOry CCartd WltWen4 Hoc OlolO Canmonieraquoi Don any CoKeem CarMWncy Earm Barrlaquoj 11 14
UPgtUnOigtturod Piuon trite (Oto20dego 0-Kgt Loei it 0-4 Sait 3O+Hofd Rock Corng 14 Kgt-30 laquo4 0 rte 4-8 MSHM Samplet TPTtitPit Ai Auger Vvanefett tarn 2Olo39 3O-M Owlt n laquo-lS Strlf rinit nn v 1
UTiUndlshffbed ThrMOll and bull 33to9O 5O Very 0laquo nraquoe 19-30 V-3trraquof - | OLE NO X-l
TOVH rim - iA it raquotoraquo
100
SHEET 2 o_L
WO WATEt STUET [AST ft OVIDENC pound a i American Drilling amp Bor ing Co Inc
MCLl WQ X- 1 Tt AOORCSS i
LIME A STA KXICCTMJ tuf same as 1 | tame as i LOCATION
W PORTSEf mo OB nj urt eflaquo T
illtPLES S
P
CVTTO nlaquo mun orv
^s f^ Tin i GRCVMO WATER OBSERVATONS CASING SAMPLER CORE BAR
START Typi COMPUTE tome at 1 same aiH
TOTAL MRS BORIMG FOR CMAN n bull IT INSPECTOR SOILS EMM
LOCATION OF BORING u HfVJTneTfi UFI _
8
Counf Blo-t
foot
Dtpllo
From To
0( on SampMr
0-6 f 6-IZ
Moittir
Oonuty or
Contilt
Strata Ctnngc
SOIL OCNTiriCATION Rtmorkt ineHifl cotot grqdotion Typlaquo of Mil etc Roo-axtrPlaquo condition Mrdshynlaquot Drog tun ttomt end tic
SAMPLE
No Ptfl RfK
434-4o4 c
approx 7 minj
per toot 454
Gray pink GRANITE Hard Fairly solid core
lt_4 24
Bottom of Boring 45 -4
-
~
bull 1
GROUND Sorrow Tye
SURHCZ 10
bull OiOry CgtCord WWothod UPUnditiurMd Piston TPlaquoTtraquotPtt AtAuotr VVor
UTltUndinrvd TTMMO bull bulltat
iivnPilaquo(onioni Uraquot4
me OioiOItttt laquoraquo20
wmt Z0ie33
and 361090
c M
C1 5 Si
-SOshy
ASING
IOtgtWtigt bullnlot Dn 10 Loci M Mod 04 SO Dm 1shy Viry 0laquo
s _
TMEN 0 hMl on 200 SoiTBUr laquoity ConcMMt Conorawncy gtbull 0-4 Sort 30shym 4-B MStlfl M BH9 Strtf bull ts-so v-swt bull
t-HOrt Ear Bern RoetCorrt
i ^^^^^ bull
-[MOLE no x-i
101
raquoMEC rAmerican Drilling amp Bor in g Co Inc 1 ofj_ DATE wo WATlaquo smn UST Plaquo IOIDCNC j laquo i
Town of South Kingstown South Kingstown 8 MOLE MO Jlt Z TC rx MCS3
rtprr uAurMonitorina Well Initollation | South KinqitowrxRI UNC A STA P KATIOM ME POCT ^rwT TO above I OFFSZT
uD^r laquorlaquorTTO 6 -109 suw tLEv Sgt louffJOCNO
0 tj Tlmlaquo WOUND WATER 06SCRVATC US gtW Rsdl SING SAM^EH CORE BAH
26 ^_ 12 $TAlaquoT UL 2Z2i Ji r TTP NW ltA sr IJZC Z5 CCOMPLETE
SitLO 3 I-3B- 1-38 TOTAL MAS 41 BOAINO FOACMAN JK1 ana nf ni n MonwwWl 300^ 140 BIT bullK^CT
gttonvrar Foil J^laquo 30mdash Diamond SOOJIEMGM
IE HFII
iCaunq SampM Trplaquo BMMtpw6 UOIIIK- SOIL DCMTIFKATION Siraia SAUPLE Blow DlaquoPIAraquo of on SompMr HtmorU mcJuo cotes gradation Type of Dwuily
pw or CXang writK Roel-eolorlyp condition tvort-From- To Vfoot 0-6 f 6-2 12-18 Coniitt egt rwtiOnAngtimt wamaondtte No Praquon Rtlt
2 Brown fine SAND little silt 2 2-0shy5 15 18 moist Browi fin to coarse SAND 18 5- 6-6 0 14 25 27 vlaquo Troc fin aravel | 25 wy Ifl 11
dlt tns 35 40 38 moist n in-il-i Lgt U 15 18 ie is li1 Irl IS 31 I2-0
~~43 1
A) Jrown coars to medium SAI MD 48 moist Little fine to coarse gravel
|5-IA-Xlaquo 14 47 41 fn D laquo y Little silt rrqa coarse sane 3 18 I1
68 In IS 44 32 34
n ^n-^i-A- w 2o 19 29 wet 4 la -59 lens ltfO no
25-0 2amp bulllaquo- 77 c BOULDER r[ 4 i
27-0 5X ~W 24 24 bullWar- 5 Ifl irown tine to coarse SAND some
dens 29-0- Fine-coars gravel trace silt
30-3I oxx 30 32 30 moist irown -gray fine SANDiom e 6 l rr Vlaquoy 31 -0 silt trace fine oroveTILL
Bottom of Boring 31 -ampbull shyBent casing -pulled out and moved over 4 - washed amp tJrovlaquo casing to 30 -Installed 3C gtof 1-12- PVC - 10 screen
WOUND SUraquoraquofCE TO 3pound 1 yijfD MW t ASIMC TMCJ laquo olaquorod -bor of borina
SomoU T]Fplaquo ProigtuliOraquoH UMd MIOtgtWLx3Orolt lon2OASanlaquoMr SUUMARY-D=Dry CCorad Wlaquoworaquonraquod bullact OiaiO CanM gnMM Daonty CIMIH Caamraquoci EffW 8or^ 2pt
UPiUnairurMd Pition Itnt laquoM2O O- O UKraquolaquo 0-4 Soft 3O-hHard Roelaquo Corrig o- JO M0mlaquo 4-8 MSNff SOTipM 1 p^ 3O-9O OwgtM bull-IS Slid
TPlaquoTraquojraquoPit AAugtr ViVon mini tamt 20to39 UTtundiifir6d TrwMOtf and JSloSO 50-raquobull Vary 0nlaquo [HOLE NO x-2 B-3O V-3Mf lev rim - IAIT raquosectlaquoraquo
102
300 iu 24
1 UMnii ffi 140 laquo 30
CA1INC tf
gt taWCTf
bull 0gtlaquo i R Cook Jr_ R Millineton1 Wttn
I~
1 VAMtl CtMG
1 W HO-t MO
1 Oraquo 1 laquo0~ twt
L 1 laquo-raquo VfcM^lf [wlaquoraquoCI ^ ^ K3Ot III laquo
0-LS D
5-65 D
LlQ 10-115 D
15-16 Tgt
Lraquo 70-51 n
25-26 D
F
I O-O Ci
A Allstate Drill ins Co vi o i
PROVIDING R 1bull raquoraquo uvraquonn~ N M O M I T O P I N G HE1 _^lt -^ PI-Traquo UJU
CUM Town of South Kineraquotown raquoraquo 1 1TA maoer Propolaquolaquod Sit for Slude Disposal nltn
laquo V-449 iampAAtut i a 138 ort STI bull r 42777 CtOuMO IKVtllON
Cill bdquo 258 DA II MN ru 42777 rilaquolaquodO laquoraquoTti rum 1911
AU1TATI
MMUI1 raquolaquogtlaquolaquo laquoKiO itXHHKraquoriOi of sous MUAHI nMTKlion Ot CMlaquoMC|kOraquort tl CO~VH DXltgt raquomlaquo laquotf IMi COIOI C4l II I 1raquo gtlaquo^ Oraquo 1Ol rC t Xgttgt VtfKOe Craquo Mi 1 ft liMraquoK laquo0^tlaquot nfgt
1-2-1 10 TOP SOIL FINE LIGHT BROWN SAND traclaquo of ilt
16-31-17
22-24-21 100 FINE TO MEDIUM LIGHT GRAY SAND trace of fine gravlaquol and raquopoundLt
lfl-37-34 150 LIGHT BROWN FINE TO MEDIUM SAND little poundinlaquo gravel
21-17-15 200 MEDIUM TO COARSE SAND bullomc fine gravel
12-4-10
265
Observation well installed
NOTE No casing blows taktn
bullbull B-23 ow
^w^ 265 I raquo bull raquolaquo bull I W
11 laquot gtbullraquo Vlaquo 14 W gt_ c-shyji bull alaquo bull jraquo VI laquoHshyw bullbull m raquobullbull D-6 raquo Mshy
bull bull laquo Vshy
1
bull bull
I
103
MAMMII Allstate Drilling Co ulaquorr 1 or 1 FftOVIOCKZ H L traquolS mTArm^S MONITOR NR WEL
VNO wr3JJO__raquoraquou_24__ HCU MO P-74 n iu riBwi Town of Slt7H^ Xirpin
mdash^ laquo0J P 1 1 bull ^n^ciit^o TVlaquow^laquott1 bullraquoit wt 140 nu 30 olaquor fBu lkv Waste Disposal Arcai
MUTAH a V-449 R Cook Jr UMlaquoiigti D 1 38 0t| raquoIJ raquo 5277 rlaquo SUMO luvlaquorv-laquow
mdash 5277 fipe -raquoT pfpm 150
H MCIO IMNTlXAflON Of SOU t(kAIlaquoS rrn 0-laquoraquo
5 -SF 01 w in laquobull -raquo ^ lit
D 1-2-2 TOP SOIL V-1-oraquo
15 IPbull FINE TO MEDIUM LIGHT GRAY SAND AND GRAVEL
5-65 D 37-27-35 some silt
10-11 D 20-14-18
15-165 D i 17-14-14 155
BROWN COARSE TO MEDIUM SAND little fine to coarse gravel trace of silt
20-211 D 4-4-2
230 GRAY BROWN VERY FINE SAND
25-26J D 7-8-9 AND SILT 265 fvarvedl
Observation well installed
NOTE No casing blows taken
wta 10 n uuraquo c^imdashbull IgtM laquolaquobull- B-24 ow ~ 14 ltfc laquoraquobull vlaquo^ M laquobull r O 0 fmtt bull W-L 26 5
-0- CgtCmdashgt bull laquolaquobull mdash laquo 1 - raquoraquo 1 gt 1laquo bull 1 gtraquor to bull mdashbull bull bull bulllaquo I t l~laquo 1lt Uraquo mdashbull ) bull 1 gtbull ft 0~ H laquoy bullM ta bull -IN la laquobull OPUM bull($ IMI
mdash H raquo laquo-bull
104
Appendix C
Calibration of Specific Conductance Meters
105
Specific conductance measurements were made using a beckman RB
338 temperature compensating meter and a YSI rtooel 33 salinity
conductivity temperature meter The YSI meter is not
temperature correcting A formula to compensate for temperature
differences to standardize YSI measurements was used (21)
A long probe for the Beckman meter was used to measure conductivity
in the wells Differences in conductivity between the YSI ana
Beckman meters and the Beckman short and long probes exist These
were calibrated in the laboratory using 001 N and 01 N KC1
solutions Values presented are Beckman short probe values The
Beckman long probe values were reduced by 76 and tne YSI values
were multiplied by 11 to adjust to Beckman short probe values The
YSI meter was used in the latter phases of the study for the
stream contamination due to the greater accuracy of the dial readout
scale
Table 7 Specific Conductance Meter Calibration Table
Concentration (KCL) 0001N 001N
Specific Beckman short 145 143 143 1247 1245 12GO
Conductances Beckman long 190 191 188 1639 1650 1665
umhocm 9 25 C YSI 132 131 128 1131 1140 1150
average values Beckman shortBeckman long = 075
Beckman shortYSI = 11
106
Appendix D
Computer program Flow Chart
107
F1g 33 Computer Program Flow Chart-
1TpoundR MAP TCO
NEWPER
WEWSTP CZAX
HEWIT TRANS TCOF ROW COLUMN
Yes
Yes
108 The following is a description of the USGS two-dimensional computer
program Iterative Digital Model for Aquifer Evaluation updated
December 1972 by P C Trescott The program written in Fortran
consists of a MAIN program and six subprograms or subroutines which
themselves are organized into subprogram sections The subroutines and
their sections are listed below
MAIN Program
DATAIN (subroutine) COEF ITER (section) CLAY MAP TRANS NEWPER TCOF
ETRATE COMPUT STORAG
NEWSTP LEAKAG NEWIT1 NEWITO CHECK ROW CWRITE COLUMN STEADY PRNTA OUTPUT DRY BLOCK DATA
The program begins in the MAIN program which controls the sequence
of passage to the subroutines Sequential steps are described in the
program as shown in the flow chart of Fig 32 Emphasis is placed on the
steady state confined aquifer case as applied in this study First data
input is read in the DATAIN subroutine This data includes transmissivities
or permeabilities starting heads storage coefficients and grid spacings
Nodal transmissivity values are then computed for the water-table problem
in the TRANS section (COEF subroutine) This procedure is necessary here
because the subsequent routine for computing iteration parameters (ITER)
keys on nodal transmissivity values which would not have been input to
the water-table problem In the water-table option these would have been
109
computed from given bedrock and water-table elevations to obtain the
saturated thickness component of the transmissivity calculation In this
study water-table option was not used and the transmissivity values were
input directly The program then passes to the ITER section (DATAIN
subroutine) to compute the iteration parameters which expediate or even
cause convergence Next the MAP section (DATAIN subroutine) is utilized
to initialize data for an alphanumeric map if this was requested in the
input options Transmissivities are then computed for the confined
(artesian) aquifer case (water table not specified with input options)
in the TCOF section (COEF subroutine) These coefficients are harmonic
mean values of adjacent nodal transmissivities weighted by grid sizes
Time parameters and pumping data for a new pumping period are then read
in the NEWPER section (DATAIN subroutine) followed by entry into the
NEWSTP section (COMPUT subroutine) which calculates the size of the
time step Leakage coefficients (hydraulic conductivity of the confining
bed divided by confining bed thickness) are next computed in the CLAY
section (COEF subroutine) if leakage was specified in the input data
which was used in this study
A new iteration is then initiated in sections NEWITO (COMPUT
subroutine) NEWITO saves the current head values and compares them to
the updated head values for determining closure This is followed by
nodal transmissivity values being computed for the water table or water-
table artesian conversion problem Transmissivity coefficients are then
computed for the water-table problem in TCOF (COEF subroutine) Total
head values are then computed with the alternating direction implicit
procedure using the Thomas algorithim first along rows in the ROW section
110 and then along columns in the COLUMN section both in the COMPUT subroutine
Then if a solution is not obtained (because the error criteria for
closure is not satisfied) the MAIN program branches back to NEWIT1 subshy
sequent sections TRANS TCOF ROW and COLUMN repeatedly until a
solution at the particular time step is achieved NEWIT1 increments the
iteration counter and is immediately followed by NEWITO The program then
moves to the STEADY section of the COMPUT subroutine to check if the
closure criteria for steady state has been satisfied Output is then
printed in the OUTPUT section of COMPUT if steady state has been reached
or if the particular time step is designated for output
The program then branches back to NEWSTP (COMPUT subroutine) and
moves through the subsequent routines until the last time step in the
pumping period is reached Output is then promoted in the DRY section
of COMPUT if specified in input data If the last pumping period in
the problem has not been reached the program branches back to the
NEWPER section and moves again through subsequent sections otherwise
the program will terminate or start a new problem if one follows
This study was simulated as a steady state problem which can be
simulated by setting the storage coefficient of the aquifer and the
specific storage of the confining bed to zero and using one time step
of any length
111
Appendix E
Computer Data Sheets
RGSEA
10 ROSE HILL LANDFILL MODEL 20 30 40 LEAKAGE 50 60 70 CHECK 80 90 100 HEAD 110 120 1 23 IQ 100 5 001 37E-OU 0 130 100 001 0 0 1 4 0 - 1 - 1 1 - 1 - 1 i i i i i i 1
ISO 1 10 0 1547E-05 01 10 1 1 160 04642 200 200 1 1 i it
1QO 190
CARDS I THROUGH 19 - CODING SHEET
CHEAD
100 110 120 130 131 132 140 141 142 150 151 152 160 161 162 163 164 165 170 171 172 173 174 175 176 177 178 179 1BO 101 190 191 192
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 539
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 58
25
25
25
25
25
25 621
25
25
25
25
25 662
25 25
25
CARD SET 2 - STARTING HEAD MATRIX (FT)
193 194 IVb 196 197 190 200 201 202 210 211 212 220 221 222 223 bull 224 225 230 231 232 233 234 235 236 237 23B 239 240 241 250 251 252 253 254 255
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 23 25 25 25 25 25
25 25 - 25 25 25 25 25 25 25 25 25- 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 - 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25
25 25
25
25 25
25 25
25 25
25
25 25
25
25 25
25
25
25
25 25
25 25
25
25 25
25 25
25 25
25
25
25 25
25
25 25
CARD SET 2 - STARTING HEAD MATRIX (FT) - continued
STORC 1512 FRI 19 FEB 82
100 110 -1 -1 - 1 - 1 0 0 120 130 140 ISO 160 170 100 190 200 210 220 230 240 230 251 260 261 262 263 270 271
CARD SET 3 - STORAGE COEFFICENT
LEAK
100 110 120 02 130 _ 18 02
I ltu 18140 025 150 02015015015 19 deg25
02 160 022 bull-laquo- J1 5 j 1 z laquo- l^
170 015 180 016 laquo02
190 016 OE025
200 02504019022021025 2 5 i S lt03 0252i2 n
230 030 deg23 deg2 deg2 deg2 -02023023 240 022 250 022025025 02
027043 013025
30() 025025025 310 025031 320 024025
CARD SET 5 - AREA OF STEAMBEDAREA OF NODE
120
Appendix F
Bibliography
121 BIBLIOGRAPHY
1 Agpar MA and 0 Langmuir Ground-Water Pollution Potential of a Landfill Above tne Water Table Groundwater V 9 No 6 1971 pp 76-96
2 Allen William B Hahn GW and RA Brackley Availability of Ground Water Upper Pawcatuck River Basin Rhode Island USGS US Government Printing-office GS 66-624 19bb
3 Annual Book of ASTM Standards Part 31 Open Channel Flow Measurement of Water and Waste Water by Weirs D 2034-68 1975
4 Annual Book of ASTM Standards Part 19 Infiltration Rate of Soils in Field Using Double-Ring Infiltrameters D 3385-75 1975
5 Baeaecner MJ and W BacK Hyarogeological Processes and Chemical Reactions of a Landfill Ground Water V 17 no 5 1979 pp 429-437
6 Beck WW Dunn AL and Grover H Emrich Leachate Quality Improvements After Top Sealing1 8th SHwRD MERL Symposium 1982
7 Beckman WK Transient Modeling For Estimating Sustained Aauifer Yield master thesis presented to the University of Rhode Island Kingston RI 1978
8 Bhattacharya PK and HP Patra Direct Current Geoelectric Sounding Elsevier Publishing Co New York 1968 135 p
9 Bouwer H Ground Water Hydrology McGraw-Hill Book Co New Yoric 1978 p 378
10 Braids 0 Cocozza pound Fenn D Isbister J Rous P and B Yarc Procedures Manual for Ground Water Monitoring at Solid Waste Disposal Facilities Environmental Protection Agency530SW-611 Cincinnati Ohio 1977
11 Cartwright K and MR McComas Geophysical Surveys in the Vicinity of Sanitary Landfills in Northeastern Illinois Groundwater V 6 no 5 1968 pp 23-30
12 Cartwright K and Fd Sherman Jr Electrical Earth Resistivity Surveying in Landfill Investigations Reprinted from Proceedings of ohe lOtn Annual Engineering and Soils Engineering Symposium Moscow Idaho 1972
122 13 Clark TP Survey of Ground-Water Protection Methods for
Illinois Landfills Groundwater V 13 no 4 1975 pp 321-331
14 Dunne T and LB Leapold Water in Environmental Planning WH Freeman and Company San Francisco 1978
15 Faro DG Upgrading Hazardous Waste Disposal Sites Remedial Approaches US Environmental Protection Agency500SW-677 Cincinnati Onio 1978
16 Fenn DG Hanley KJ and TV Degeare Use of the Water Balance Method for Predicting Leachate Generation From Solia Waste Disposal Sites US Environmental Protection Agency530SW-lfa8 Cincinnati Ohio 1975
17 Geisser 0 An Electric Analog and Digital Computer Model of the Chipuxet Ground Water^ Aquifer Kingston Rhode Island master thesis presented to the University of Rhode Island Kingston RI 1975
18 Hahn GW Groundwater Map of the Narragansett Pier Quadrangle Rhode Island Rhode Island Water Resources Coordinating Board GWM 5 1959
19 Hemsley William T Koster C Wallace Remedial Technique of Controlling and Treating Low Volume Leachate Discharge USEPA National Conference on Management of Uncontrolled Hazardous Waste Sites Oct 1980
20 Hughes GM RA Landon and RN Farvolden Hydrogeology of Solid Waste Disposal Sites in Northeastern Illinois Final Report to US Environmental Protection Agency PUD SW-l^d Cincinnati Ohio 1971
21 Keller GV and FC Frischknecht Electrical Methods in Geophysical Prospecting Pergamon Press New YorK NY 19bb
22 Kelly WE West Kingston Landfill An Evaluation of Its Effect on Ground-Water Quality Rnoae Island Water Resources Board Water Information Series Report 1975
23 Kelly WE Geoelectric Sounding for Delineating Ground-Water Contamination Groundwater V 14 No 1 1976 pp fa-10
24 Kelly WE Ground-Water Pollution Near a Landfill ASCE Environmental Engineering Division Journal V 10 No EE6 Dec 19b pp nay-nyy
25 Kelly WE personal communication January 1982
123
26 Kelly WE and OW Urish A Study of the Effects of Salt Storage Practices on Surface ana Ground Water Quality in Rhode Island NTIS FHWA-RI-RD-8001 1981 54 p
27 Kimmel GE and OC Braids Leachate Plumes in a Highly Permeable Aauifer Groundwater y 12 no 6 1974 pp 388-393
28 Klefstaa G Senalein LVA ana RC Palmauist Limitations of the Electrical Resistivity Method in Landfill Investigations Groundwater V 13 No 5 1975 pp 418-427
29 Landon RA Application of Hydrogeology to the Selection of Refuse Disposal Sites Groundwater V 7 no b 19b9 pp 9-13
30 Lang SM Bierschenk WH ana WB Allen 1960 Hyaraulic Characteristics of Glacial Outwash in Rhode Island Rhode Islana Water Resources Coordinating Board Bulletin No 3
31 LeGrand HE Patterns of Contaminated Zones of Water in the Ground Water Resources Research v 1 No 1 1965
32 Palmauist R and L Sendlein The Configuration of Contamination Enclaves from Refuse Disposal Sites on Floodplains Grouna Water v 13 no 2 1975 pp 167-181
33 Pinder GF A Digital Model for Aauifer Evaluation Techniaues of Water Resources Investigations of the US Geological Survey Bk 7 Cl 1970
34 Purushattam D Tamxe GR and CM Stoffel Leachate Production at Sanitary Landfill Sites ASCE Environmental Engineering Division Journal V 103 no EE 6 Dec1977 pp 981-988
35 Remson I Fungaroli AA ana AW Lawrence Water Movement in an Unsaturated Sanitary Landfill ASCE Sanitary Engineering Division Journal v 94 no SA2 April1968 pp 307-316
36 Rosenshien JS Gouthier JB and WB Allen Hydrologic Characteristics and Sustained Yield of Principal Ground-Water Units Potowamut-Wickford Area Rhoae Island USGS US Government Printing Office GS 67-324 1968
37 Roux PH and B Vincent Electrical Resistivity Evaluations At Solid Waste Disposal Facilities US Environmental Protection Agency SW-729 Cincinnati Ohio 1978
124
38 Salvato JA Wi lk ie WG and BE Mead Sanitary Landfill Leaching Prevention and Control Water Pollution Control Federation Journal v 43 no 10 Oct 1971 pp 2084-2100
39 Sawyer CN and PL McCarty Chemistry for Environmental Engineering McGraw Hill 1978
40 Stellar RL and P Roux Earth Resist ivi ty Surveys - A Method for Defining Ground-Water Contamination Ground Water v 13 no 2 1975 pp 145-150
41 Todd OK Ground Water Hydrology John Wi ley and Sons Inc New York 1959
42 Tolman AL Ballestero AP Beck WW and GH Emrich Guidance Mannual For Minimizing Pollution From Waste Disposal Sites US Environmental Protection Agency-500SW-677 Cincinnati Ohio 1978
43 Trescott PC Iterative Digital Model for Aauifer Evaluation US Geological Survey Open file report 1972
44 University of Rhode Island Academic Computer Center CalComp Contouring Manual
45 Warner DL Preliminary Field Studies Using Earth Resistivity Measurements for Delineating Zones of Contaminated Ground Water Groundwater v 7 1969 pp 9-16
46 White EF A Report to the Town of S Kingstown Utility Survey Engineering Corp 1967
47 Zohdy AAR A Computer Program for the Calculation of Schlumberger Sounding Curves Over Horizontally Layered Media Using the Method of Convolution US Geological Survey Denver
48 Zohdy AAR Eaton GP and DR Mabey Application of Surface Geophysics to Ground-Water Investigations Technidues of Water-Resources Investigations of the US Geological Survey Book 2 Chapter 01 Washington US Government Printing Office 2401-02543 1974
Table of Contents
Page
Title Page
Approval Sheet
Acknowledgement ii
Thesis Abstract iii
Preface iv
Tab I e of Contents v
List of Tables vi
List of Figures vii
Main Body
Introduction 1
Background 2
Description of Study Area 10
Field Studies and Procedures 15
Model Development 30
Model Calibration 41
Computer Simulations 42
Analysis ana Discussion 55
Remedial Measures and Recommendations 75
Conclusions and Recommendations 83
Appendices
Appendix A Precipitation Records 86
98
Appendix C
106
Appendix E
120
Appendix B Boring Logs
Appendix D Computer Program Flow Chart
Appendix F Bioliography
CaliDration of Specific Conductance Meters in4
Computer Data Sheets Ill
VI
List of Tables
Table
1 Well point Water Elevations 17
2 Seismic Refraction Survey Results 20
3 S tream Fl ows 22
4 Specific Conductances in Well points 26
5 Specific Conductances in Streams and Observation Holes 27
6 Schlumberger Vertical Electrical Sounding Results 27
7 Specific Conductance Meter Calibration Table 105
Vl l
List of Figures
Figure
1 Location Map 2
2 Study Area 3
3 SupplyWel l Locations 4
4 Field Grouna-Water Table Contour Map 5
5 Ground-water Map 12
6 Geology Background Map 13
7 Fluctuation in Water Level in W e l l s 16
8 Seismic Survey Location 19
9 We i r Locations and Water Level Ranges 21
10 Surface Contamination Monitoring Locations 24
11 Fluctuation in Specific Conductance in W e l l s 25
12 Electrical Resist iv i ty Sounding Location 28
1 3 Model Grid 31
14 Simulated Ground Water Table Contour Map 32
1 5 Northern Drainage Area 34
16 Landfill West-East Cross-section between Wells W and EC 39
17 Landfill North-South Cross-section between Wells NW and SC40
18 Natural Conditions 43
19 Excavation without Landfill 45
20 Landfill without Excavation 46
21 Landfill Head Contour Cross-section 47
22 Landfill and Excavation with Dam 49
23 Summer Condition 52
24 Landfill ana Excavation without Dam 54
VI 1
25 Infiltrometer Location and Drainage Feature 57
26 Results of Infiltrometer Tests 59
27 Schlumberger Sounding R-l 71
28 Schlumberger Sounding R-2 72
29 No Recharge over Lanafill 77
30 SI urry Wall 80
31 Slurry Wall without Recnarge Over It or Landfill 81
32 Precipitation Record 87
33 Computer Program Flow Chart 107
Introduction
Ground-water contamination of aauifers from municipal landfills
is a widespread problem Contamination of domestic supply wells and
neighboring streams has occured at the South Kingstown municipal
landfill which is located adjacent to Rose H i l l Road approximately
one mile nortn of Peace Dale Rhode Island (Fig 12) The polluted
neighboring wells have been relocated to their present locations to
remove them from tne leacnate plume (Fig 3) Fig 4 inaicates flow
patterns from the landfill which has contaminated streams to the
east and southwest of it The generation of leachate continues as
precipitation recharge and upgradient ground-water sources
infiltrate the refuse To effectively prevent or minimize
contamination from this landfill several remedial options are
available These w i l l be evaluated relative to the areas geologic
setting and hydraulic properties ground-water flow patterns
recharge characteristics and proximity to supply sources
The rate of ground-water flow out of the landfill into the
adjacent aauifer and flow patterns largely depend on tne hydraulic
gradient of the water table and the hydraulic conductivity of the
landfill and aduifer material The hydraulic gradients were
determined by monitoring water-table fluctuations in several wells
located around the landfill and elevation siting in stream
locations and elevations This information enabled a ground-water
map of the area to be developed from where flow patterns can be
developed assuming flow lines are orthogonal to contour lines The
ground-water map in combination with Knowing aquifer and landfill
N
^ooo
feet
Fig 1 Location Map
3
peoy ||H asoa
X ltbull
Alt
f c c
o
^ ^ o o f a
O OJ 83X1
o O
x o
seepage observation -t West
hole Landfill Area
Legend mdash landfill limit bull j--excavation limit r^-s stream copy WNWNEECSeuroSCSEN
monitoring well locations = = = unimproved road
A contaminated domesti supply well
D uncontaminated domestic supply well
feet
Fig 3 Supply Well Locations
5
a 03
N lo ^ gt
laquo c 2
mdash w
3
X o ^
3 O L
o CO
0 opound E bullo
0
co
c
o0
uj ^
0 o o c
o $ bullA
E c o
w
bullo t_hraquo9 O
_OplusmnJ ca
u
pro
ve I 51 H
bullo 0gt
UJ _c e poundbullo Mzbull w gt 0
laquorege cc
0gt -^^ o a5 raquobull bullo o sect 3 mdash laquoo o wcz _
3Ogt c $c o_ X
aw e 05 0 (0 3 bullo
o a 2 2 u
hydraulic properties and the subsurface geometry enable estimates of
ground-water outflow to be made Streamflow measurements were used
to verify these outflows Contamination levels using specific
conductance measurements as an indicator were measured in wells
streams and observation holes to help delineate the extent ana
degree of contamination An electrical resistivity sounding was
conducted in a known contamination zone
The primary objective of tnis study is to determine flow
patterns in the vicinity of the landfill ana recommend possible
actions to contain or minimize the impact of the contamination In
oraer to fully evaluate these goals the aforementioned parameters
were input to a computer model to produce simulated flow patterns
under different conditions The simulated present conditions were
matched with field water table and stream flow measurements to
calibrate the model A series of simulations were then run to
evaluate flow conditions before the excavations anaor landfill
existed Remedial measures such as reducing recharge to the
landfill and implementing a slurry wall to blocx off leachate flow
to endangered wells were simulated to evaluate their effectiveness
Based on this analysis recommendations are made as to how to
minimize leachate production ano best alleviate the immediate danger
of the contaminant plume spreading to unpolluted domestic supply
wells
background
The South Kingstown landfill is in a geologic setting that is
very similiar to the nearby West Kingston landfill This is located
about 3 miles west of the South Kingstown landfill and has been
studied to assess leachate effects on groundwater quality using
specific conductance as an indicator of contamination levels
(222ltt) Both sites were located in abandoned gravel Quarries which
were filled in with refuse to create the landfill
In the literature numerous authors have shown that the character
of contaminant plumes from landfills are largely dependent on the
local geology and geohydrology A study on Long Island (27) in
similiar glacial material illustrates that the Quantity of flow is
dependent on the hydraulic conductivity of tne aauifer the
hydraulic gradient and the vertical cross-sectional area of the
aauifer it flows through This is expressed as Darcys Law (41)
Q = KIA
wnere Q = flow quantity
I = hydraulic gradient
K = hydraulic conductivity of the aauifer
A = vertical cross sectional area of the flow area
Specific conductance was used as a contaminant tracer to show that
the plume from the landfill flowed downgradient and vertically
through the full thickness of the aauifer A study in Iowa (32)
indicates that the size ana shape of the contamination outflow from
a l a n d f i l l can be predicted from existing geohydrologic conditions
and that the horizontal shape of the outflow extends downgradient
8
from the source and parallel to ground-water flow lines Other
parameters which control the extent of the contaminant plume are
dilution and dispersion in the aquifer and the adsorption properties
of the aauifer material (31)
The amount of leachate generated depends largely on the amount
of water that infiltrates through the landfill to increase tne water
content of the refuse in the landfill The precipitation recharge
that percolates down through the unsaturated zone to the water table
moves in a vertical direction (35) Surface runoff soil moisture
storage losses and evapotranspiration account for tne precipitation
that is not transmitted tnrough the unsaturated zone of aeration
(3315) Upon reaching the saturated zone the water enters the
ground-water flow system Ground-water mounding has been reported
in landfills due to the decreased hydraulic conductivity of
compacted refuse relative to surrounding aauifer material (20)
Chemical processes within the landfill leachate outflow and
surrounding soil cation exchange capacity relative to water duality
of the surrounding aduifer have been studied in Pennsylvania (1) anu
in Delaware (5) A procedures manual for ground-water monitoring at
solid waste disposal facilities was developed by the US
Environmental Protection Agency (USEPA) (9)
Several reports have been written that investigate site
selection design criteria and remedial measures to correct
leachate problems (29) A survey of ground-water protection methods
for landfills in Illinois studies relationships to the water table
theory of liner installation and monitoring devices (13) Sanitary
Landfi11-Leaching Prevention and Control presents a review of
preventative methods such as means to minimize infiltration
interception of ground-water and other pollution control measures
(2 37) A study in Pennsylvania on actual measures implemented to
collect and treat a landfills leachate discharge presents a site
specific study (19) Leachate Quality Improvements After Top
Sealing1 shows that by minimizing infiltration at a landfill in
Connecticut the outflow leachate water quality can be improved
dramatically and contamination plume reduced significantly (6) The
most comprehensive reports on remedial approaches to upgrading waste
disposal sites and ground-water protection methods have been
compiled under USEPA contract (1542)
To assist in evaluating remedial measures the US Geological
Survey (USGS) computer model Iterative Digital Model for Aduifer
Evaluation was used It was originally developed as a model for
simulating two-dimensional aauifer problems (33) It had been
updated since its original development to accomodate different
options (43) This model has been applied to glacial outwash
regions in Rhode Island (717)
10
Description of Study Area
A map of tne landfill area (Fig Z) was obtained from tne town
of South Kingstown The excavation to the west of Rose Hill Roaa
the landfill area directly to the east and the presently operating
area to the east of the central stream comprise tne overall study
area This study will concentrate on the west landfill area whicn
has recently reached capacity and been closed to further dumping
This site received mixed refuse for the past 15 years The depth of
the excavation where the landfill presently exists was approximately
to bedrock in some places Tne exact depths of landfill material is
unknown
The landfill cover has been graded and sloped generally eastward
to convey surface runoff to the eastern side A sandy soil that was
excavated locally was used as tne cover material The northern
section has a vegetation cover and the recently filled southern
section has been seeded and mulched The six monitoring wells W
NW NE EC SE SC were placed by the town of South Kingstown to
provide water quality information
Referring to Fig 2 the west excavation stream drains the area
created by the excavation to the west of Rose Hill Road and flows
throughout the year The central stream drains a small watershed
area which lies to the northwest of the landfill and drys up during
part of the year These streams flow into the Saugatucket River
which flows throughout the year and is larger than the west and
central streams combined
11
The USGS Groundwater Map (18) was initially consulted to proviae
information on the ground-water flow patterns (Fig 5) and the
geology of tne area (Fig 6) The surficial geology borings and the
vertical geologic cross-section at the base of the study area
indicate shallow water table and bedrocic and a nearly constant
saturated thickness (18) Boring logs at the W well ana a point
approximately 150 feet south of it indicate glacial outwasn material
which is primarily sana with a trace of gravel over bedrock at a
depth of approximately 33 feet Borings at the east landfill area N
and S monitoring wells indicate the same aquifer material
(Appendix B)
The ground-water map developed by Hahn is taken as
representative of conditions existing prior to the excavation of the
I l andfill (18) This indicates water-table contour lines that run in i
a general northeasterly direction This means tnat flow was
originally in a southeasterly direction However contamination of
domestic supply wells on the west side of Rose Hill Road has
occurred (Fig 3) strongly suggesting that the original flow pattern
has been altered by the excavation to the west of Rose Hill Road and
the landfill to the east of it Domestic supply wells were formerly
located directly to the west of Rose Hill Road but were aoandoned
when they became contaminated from landfill leachate New wells
were located to the south and west away from the contaminant plume
of tne landfill In addition a well located at the northeastern
corner of the landfill was contaminated and a replacement located to
the east of Us former location on tne opposite side of the central
12
Legend scale 124000
mdash-40 mdashground-water contour elevation
Fig 5 Ground-Water Map
13
Legend feet
TILL
Fig 6 Geology Background Map
14
stream This second wel 1 also became contaminated Domestic supply
wells located near tne northwestern corner of tne landfill and
approximately 300 feet south of it nave remained uncontaminated
These well locations serve as an indication of tne extent of the
landfill contamination which is largely dependent on the groundwater
flow patterns To furtner investigate this problem and provide
substantial information on which to base the geohydrologic analysis
field studies of the area were conducted
15
Field Studies ana Procedures
A map of the lanafill and an aerial pnotograph of the area were
obtained A tracing of these maps superimposed upon another
delineates stream landfill and monitor well locations (Fig 2)
The field investigation concentrated on the west landfill area ana
its aajoining streams ana monitor wells The east landfill area and
the three monitor wells in that area are induced in the latter
phase of the study in oraer to expand the model area
A traverse which establishea tne monitor well elevations was run
using a Carl Zeiss level These were originally sitea in by the
town of South Kingstown using a local USGS reference datum number 40
(18) The wells of known elevations then served as benchmarks for
referencing adjacent stream elevations This in combination with
the depth to water table measurements at each well enables tne
water-table surface geometry of the area to oe visualized
Water-table measurements of the west landfills wells were recordea
over a ten month period to record fluctuations (Fig 7 Table 1)
The east landfill areas wells were monitored for a five month
period Using a given water-table condition a ground-water map was
developea of the area (Fig 4) This indicates an outflow from
the landfill primarily in a southeasterly direction and partially
in a southwesterly direction
Additional bedrock and water-table information was ootainea by a
seismic refraction survey at several locations along the landfill
perimeter A Bison Model lb70C Signal Enhancement Seismograpn was
used to maxe the surveys Lines were run (to a length of kOO feet)
16
17
w s p bdquo S bdquo s S S a laquolaquo _
s 2 8
V
r bdquo
3 s a
-R s
S
S 3
t
raquobullraquo
S
5
K
r
~
3
K
pound
7
S
bdquo3
C 5 S
shy raquo S s
1 3 s 3 2 5 ^ bull
5 m
s o
^ 3
raquo
--
R bull 5
s pound J O s
5 a 3 7 3 m
5 s a ^
iraquo a s rlaquo
M ^
^ c o 2 5 s 3 a S R
rd 3 y a O =J
^ bdquo
JJ s s 3 bull ~ I
~ s 5 3 a s a
(Ogt (U
2
-t =
r s s in
5 y
a s
5
3
s
5 a
^ a
3 a 51 a bullbull
sj 5 Ml
3 a bull
s raquo
a
0)
0
^ mdash
a j -
-3
C
g S
S
bull a
-
~ 3 o
2 s s 3 a bdquo s s $ Al s
(1) = $ s 3
S
c a a
3 e 5 s N s S a - 3 = s s a 5
a s s - 3 S shy
4
0
a s
bdquo tfH
bdquo
3 a
bdquo
s a
e bullfl s i s s a s a
3 nt
s s 3
g laquo s3 a
~ J s 2 a s o s S s 3 a a j laquo s o s
3 bull laquobull
2 a 7 3 a 3 a ^2
s mdash 5i o
bull bull
mdash
3 o
ss a
fc mdash
3 1-sect m ishy n
18
in both directions to provide a check and permit accurate estimates
of the depth to bedrockThe seismic results allow approximate
interpretations of the depth to the water table and bedrocK thus
permitting an estimation of the saturated thickness Ground
elevations at the location of the seismic surveys were determined
from a topographical map and field siting From this information
water table ana bedrock elevations estimates were made Bedrock
contours are listed in Fig 8 In addition a table which
summarizes the seismic refraction results for the unsaturated
saturated and bedrock layers velocities and depths at each survey
location is presented in Table 2
Scream gauging stations were established on the two streams
bordering the west landfill (Fig 9) Three stations were placed on
the central stream These provide information on the influent or
effluent condition of ground-water flow in the upper sections of the
stream and ground-water baseflow from an area adjacent to the
landfill into the stream (Table 3)
The stream gauging stations used were 90deg V-notch weirs The
weirs located in the SE and SW positions were placed in the
streamoea with a liner of plastic upstream to minimize underflow
The weirs located in the NW and E positions were cut to fit in
recesses of concrete culvert pipes Concrete plywooa interfaces
were coated with roofing cement to minimize bypass flow Upstream
water pressure and a snug fit hold the plywood sections in place
All weirs were implaceo according to AigtTM reouirements and flowrates
calculated using the standard 90deg V-notch formula (3)
19
N
seepage West observat ion Landfill hole
Area
Legend landfill limit excavat ion limit
copyWNWNEECSESC monitoring well locations
= = = unimproved road -- WNES-number
seismic refraction locations
-40shy approximate bedrock contpur elevation
feet
Fig8 Seismte Survey Location
20
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co CM o on on CO CM CTNVO VO co CM o on on Q gt_x rH oj on a oj on a - rH oner
rmdash on sr i i
M z Z
gt gt gt
X-N CO laquomdashv CO CO bull igt gt bull
1 gt fc^gtgt bullbull ^ ^ ^
C 4-gt O t igt O J- 4J O H m o o o 3 bullH CO O rH in 3 bullH co vo o in 3 ~ 1 i-k -i ^trade fj rj ui ij o CO o n o rH =r co o n vo vo vo co o bullv O O O
O raquo On-3 rH O -bull- rH ON in _ IH in oj - rH bull rH VO OrH bull rH On ON pH d)u CO -UCO 4J OJ CO 4-gt gt
C mdashbull gt CM gt CM H-l O CO
v- ^^ N C 0
bull0 N CO
4-5 -0 _c^gt in in CO CO
C x~ c -^ t-oo in i 4J j_gt 41 4J bull 9 bull bull 4J bull
o j ON O O 3 (0 O4J O ON ON QJJ t~-^3- OJ 4-gt L
CO CM trade CO CM rH rH OJ co CM oj on Q ^ _ CO 3~Q-- n 45 Q mdash OJ OJ OJ C (0
1 11 3 nZ 2CO
gti gt gt CO CO CO ^-x m -s CO
rH rH ^ ro^^ bull gt bull ^ igt gt bullgt gtgt bull r O -Q 4Ji JJ O 5- JJ O pound- ^ O 4) oj o on (0 CO
3 bullH CJ O O in 3 bullH CO Cmdash VO on 3 pound-laquo H CO o n in inco co o n ma- r co g^ 5sect^ o
o rH on oj O bull- rH ONCO L O_ rH OJ VO M
rH bull rH =t rH bull - OJ T CO CO M CO 4-gt rH CO -U rH CO 4-) s
uits
CO 4-gt 4-5 T3 gt CM gt CM gt CM cc CO CO CO
3 3gt oa tlp^ CO O CM O gt 4J O 40 i 3 r+ k C pound JS
CO pound
^^ s -bullgt cmdash on poundZ VO CTI trx 4J 4J 4J
) bull bull bull Q Q Q Q4J 3shyc O-JJ CTgt OJ OJ Q-IJ inco on CO CO CO o co CM oj on co CM oj on co CM on
Q Q QON^ Q bullH Q^
rH rH 4J rH
O bullraquo L Z bull CO CO CO
i gtgt rH oj on gt tgtshyCM ^ cO^-s CO ~ CO
CO CO J X fc^_ bull^gt bullgtgt bull gt gtgt bull gt CO
j_ jJ O pound- Jj -P O Li deg =fObullH co on f- ^ 3bullH CO CO O in 3bullH CO
g^ -^2
poundsect HO
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mic
3 CO in in in in in in co o n co o n
o -^ r oj in O rHCO CO rH bullrH bull rH =T OrH bull rH OJ f-CO 4J bull- CO 4J rH O0) J-)
gt CM gt CM gt CM 4J
CO N_^ m^
bull OJ
t t poundshyCO CO CO CO rH J3 gt r-t oj on gt r-i oj on gt gt r n o j o n
lto co lto CO T bull ii-4 laquomdash bullmdashH
bullo CO L L 0)
CM CO cc
21
N
545-594
seepage observation
hole West Landfill
0NE I47-509
Area
Weir 45
i487-531
0 EC Al3-467
Legend bullmdash landfill limit -bull---excavation limit r-s stream
copy WNWNEECSESCSEN monitoring well locations
= = = unimproved road
Weir location and elevation
feet
Fig 9 Weir Locations and Wate r Level Ranges
22
JT NO
S shy S
O
bull ry m
oa
NO
(M raquo 1 03 or NO m
JT O O raquo
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PW tn in ^4 fraquo
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i ru
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i ^
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1 pound OJ
3 oi g bull
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1 pound laquolt bull
3 bull o a
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5 laquo15
f bull 3 Jl s
5bull 1 5
23
A field study to determine the infiltration capacity of a
section of tne landfill topcover was conaucted A modified version
of a double ring infiltrometer was used to study infiltration rates
(4) The cylinder diameters useo in this study were 8 inches and 18
inches A constant head of 6 in was maintained in the
infiltrometer and rates of infiltration were determined Tnese
results and an analysis of surface infiltration into the landfill
are included in tne analysis and discussion section
Specific conductance levels in the monitoring wells in the
streams bordering the landfill and at observation holes near the
landfill were measured (Fig 10) This is a good indication of the
mineralization of water (39) Specific conductances were measured
intermittently over the ten month period to develop a picture of the
extent and degree of contamination in the wells (Fig 11 Taole4j
and in the surface contamination monitoring locations (Fig 11
Table 5) A comparative standardization of the Beckman (short and
long probes) and YSI specific conductances is in Appendix C
A surface electrical sounding using the Schlumberger array was
conducted adjacent to Rose Hill Road at the R-l location (Fig 12)
in an attempt to delineate the vertical extent of the contamination
zone Well W was used as a centerpoint and a reference for
water-table depth pore water conductivity and depth to bedrock A
Schlumberger array electrical resistivity sounding was also
conducted in an uncontaminated area at tne R-2 location (Fig 12) to
provide a comparison background interpretation A seismic
refraction survey N-4 was conducted at the same location (Fig 8J to
24
N
excavat ion
Seepage West observat ion Landfill hole
Area
Stream 1 Seasonal observation 0 EC
hole
East Stream2
Legend sw Weir landfill limit j--1--^ excavation limit
copyWNWNEECSESC monitoring well locations
== unimproved road
feet
Fig 10 Surface Contamination Monitoring Locations
25
8000T
7000
O bull U) W6000
Legend
0 sc A NE O W
A SE O N W
a EC
1 O N D J F M M
Time months Flg11 Flucuatlon In Specific Conductance in Wells
26
Table 4 Specific Conductances in Wells (pmhoscm at 25degC)
West East Landfill Landfill
Date NW NE EG SE W SC N E S
81581 851 938 236 2356
102981 171 3268
11381 3268
111081 304 988 1100 258 3800
111481 426 2736 1216 186 4560
111781 304 3610 433 389 4560
121981 380 1406 129 103 380
1982 160 152
31582 274 760 1064 61 334 8000+ 182 53 84
52182 450 1500 1125 112 712 8000+ 175 255 150
52282 425 1320 1200 110 850 180 320 170
27
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in rH cmdash
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28
excavation
West Landfill
Area
Legend bullmdash landfill limit -bullbull--bullexcavation limit r~~s stream
copy WNWNEECSESCSEN monitoring well locations
= == unimproved road
electrical resistivity sounding
feet Fig12 Electrical Resistivity Sounding Location
L
29
allow estimates of depth to water table and bedrocic to be made
Soundings were carried out to 500 foot electrode spacings to insure
that hredrock was penetrated and to facilitate interpretation These
results and a discussion of the soundings interpretation are
included in the analysis and discussion section Schlumoerger
resistivity soundings were made using a Soiltest R-bO unit
30
Model Development
The USGS Iterative Digital Model for Aauifer Evaluation was
usea to develop steady state flow models of the study area (43) A
flow chart of the computer model and a brief explanation of the
subroutines usea is presented in Appendix D The stream locations
elevations and aauiferlandfil1 geometry and hydraulic properties
were input to the model to compute head values at each 200 foot
grid spacing node (Fig 13) The input data which is for the
existing excavation and landfill conditon is listed in Appendix E
The head values that are computed at each grid space are in turn
loaded into the CalComp plotting routine (44) where a grid spacing
is setup with the computed head values at each node The contouring
program linearly interpolates between these head values and
generates a contour map The computer simulated ground-water
contour map for the excavation and landfill is presented in Fig
14
The streams in the model generally serve as controlling boundary
conditions When using computer simulated geohydrologic models of
an area choosing the boundary conditions for the model that are the
same as prevailing conditions in the field is a critical step in
model development Extending the models boundaries to areas in the
field that have a minimum influx of ground-water across them
simplifies the proolem of calculating fluxes from outside the model
area The eastern boundary is bordered by glacial till which has a
low hydraulic conductivity estimated to be 67 ftday(2) This
contrasts to the high hydraulic conductivity of glacial outwash that
makes up the model area of approximately 107 ftday(3036j
31 N
o 9
bullO O
32
33
The Saugatucket River serves as the controlling boundary on the
east A small drainage area directly to the east of it provides a
minimal influx
Beyond the moaels northern boundary the glacial outwash valley
extends to the base of a till covered h i l l on the western half ana
on the eastern side extends along the Saugatucket stream Due to
the relatively large drainage area that lies upgradient from the
northern boundary a recharge flux eduivalent to 10 inyr over the
drainage area on the till hill and outwash area north of the model
area was input as underflow (Fig Ib) Part of this was input at
each northern boundary node Till has a lower infiltration capacity
than outwash so more of the precipitation w i l l be transmitted as
overland runoff resulting in a lower ground-water baseflow The 10
inyr of recharge that results in a ground-water inflow from the
combined till and outwash region represents an estimate that is
smaller than the 14 inyr recharge for glacial outwash areas in
Rhode Island (25)
The glacial outwash valley extends beyond the western boundary
No significant ground-water recharge flux was estimated at this
boundary A relatively low ground-water gradient exists to the west
of this which does not provide a significant flux across this
boundary Tne southern boundary is basically the outflow region for
the area and therefore would not reauire any ground-water flux into
the moael area across this boundary This boundary was set south of
the point that the streams in the model merge together Therefore
the streams which lie to the north of it are the controlling
34
scale 124000
Fig 15 Northern Drainage Area
35
boundary conditions The flux out of the downgradient outflow
region approximately eauals the influx from precipitation recharge
and boundary influxes
When tne stream configuration in the moael area are reviewed it
can be seen that they comprise a large portion of the boundary
area The screams can act as sources or sinks for water in the
model thus providing to and removing water from the aquifer The
leakance option was used in the model which provides for a confining
bed and aouifer area beneath the stream to be input
The leakance is defined as the hydraulic conductance of the
streambed divided by the streambed thickness which in this case is
taken as 1 foot The leakance value at each streambed node
restricts the flow between the aduifer and the stream The
streambed hydraulic conductivity is typically 01 the value of tne
hydraulic conductivity of the aduifer (717) The value 107
ftday was used for a streambed conductivity based on a value of
107 ftday for the aquifer The aduifer and stream hydraulic
inputoutput exchange at eacn node is calculated by initially
finding the difference between the initial field stream head
elevations and the computed head elevation values at the
corresponding nodes This head value is then multiplied by the
(Leakance value at each node) x (stream area of each node)
Therefore if the aduifer head was lower than the stream head the
stream would act as a source of water for the aquifer and vice
versa
36
Tne leaxance input at each stream node is the ratio of the
actual field streambed area in each node to the area of each node
which is 200 ft x 200 ft = 4 x 104 ft2 The west
excavations stream width is approximately 3 ft central 4 ft and
east 5 ft Therefore if tne west stream traverses the node
directly without meandering it presents a leakance of 3 ft x 200
ft4 x 104 ft = 015 Leakance and streamhead values were
input at each node to set up the stream flow parameters in the
models
A recharge value of 14 inyr over the entire area was input at
each node This represents a value of precipitation that is
transmuted into tne ground-water rather than being directly
evaporated evapotranspired through plants or overland flow
runoff The precipitation recharge flow from the stream into the
aauifer and boundary fluxes provide the model witn input flow
parameters
From analyzing the available information it was determined that
the study area lies within a glacial outwash area with a relatively
shallow bedrock The seismic survey around the landfill generally
indicates a depth to bedrock below the land surface of approximately
29-43 ft with corresponding saturated thicknesses of 19-33 ft as
seen in Table 2 This agrees with borings from tne USGS groundwater
map in the stuuy area (18j The seismic survey was run at a low
water table condition which was several feet below the high water
table level (Fig 9)
37
High water-table saturated thicknesses were used to develop
model parameters For the purpose of this model study the saturated
thickness was set at 30 ft except in the vicinity of well W where
there is a bedrock high (Fig 8) At this location a high water
table saturateo tnicxness of 8 ft was estimated In tne vicinity
the seismic survey was conducted the bedrock elevation at this
location is the highest and the saturated thickness the least Tnis
can be seen by an east-west cross section of tne landfill (Fig 16
The boring log for well W indicates a sand trace gravel outwash
material (Appendix B) Boring logs at the eastern landfill area N
and E indicate similar material On this basis the hydraulic
conductivity was estimated at 107 ftday (3036) Witn the
exception of the landfill and the bedrock hign areas the
transmissivity values were set at 107 ftday x 30 ft = 3210
fto day From the literature the hydraulic conductivity of the
landfill material was estimated at I ftday (19) The
transmissivity of the landfill material in tne nortnern section was
estimatea at 1 ftday x 30 ft = 30 ft^day or approximately two
orders of magnitude lower than the outwash In tne landfills
southern section the original excavation was not as deep as in the
northern parts The landfill material was estimated to makeup only
one half tne saturated depth the remainder being the original
glacial outwash material (Fig 17) Therefore the transmissivity
at the southern end was estimated at 15 ft x 107 ftday + lb ft x
1 ftday = 1620 ft^day These values were graded into the 30
ft^day values at the landfills northern halfway point These
38
were input as transmissivity values to the model at their respective
locations This model did not use the water taole option so
water-table fluctuations did not affect the transmissivities
39
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Model Calibration
A simulation was run using the initial estimates of stream
parameters aquifer and landfill hydraulic conductivities
transmissivities boundary and recharge conditions to approximate
water taole conditions in tne fiela Initially the existing
condition of the excavation area to tne west of Rose Hill Road and
the landfill to tne east were modeled in order to calibrate the
model to current field conditions as shown on Fig 4 The simulated
well values (Fig 14) fall within tne range of field values (Fig
9) The resulting contours also provide an approximate matcn This
can be seen by comparing Fig 4 with Fig 14 An additional check
was to match the flow loss and gain in the streams between tne weirs
in the central stream which w i l l be discussed later The
simulated flow value from the excavation drainage stream is the same
as that measured at the SW weir location Having calibrated the
model by approximately matching well water levels nead contours
and scream flow values different field conditions and possible
remedial measures can be simulated
When the model grid was laid out over the study area as viewed on
Fig 13 the stream configuration rarely traversed the grid nodes near
their central axis When the stream locations were input to the
computer the information was documented as crossing the central axis
of the grid nodes The result of this is a slight aberration when
the actual stream configuration is laid over the computer graphics
head contour output The streams dont always cross the groundshy
water contour at the logical location Rather than modifying the
actual stream configuration to adjust then to the computer output
their actual locations are presented
42
Simulations
i The primary focus of the computer modeling is to analyze flow
patterns under changing conaitions in the near vicinity of tne raquo
landfill The study areas overall flow patterns as they exist
today are first presented in order to realize the lateral east-west
head contour lines between the stream that directly borders the
landfill on the east side and the SaugatucKet stream (Fig 14)
This indicates a general southerly flow direction in that area As
different conditions are modeled these contours generally maintain
their east-west orientation In order to facilitate interpretation
of flow patterns in the near vicinity of the landfill flow patterns
to the west of the stream that borders the east side of the landfill
r are presented in the subseauent models
L- Natural Conditions
The results of modeling the original natural conditions are
shown in Fig 18 The excavation and stream to tne west of Rose
Hill Road and tne landfill did not exist in this simulation The
southwestern boundary consists of a drainage stream that was
delineated using an aerial photograph and stream elevations were set
using the topographical map The USGS ground-water map (18) was
used to estimate head values between the west excavation and north
streams These were input to the model as constant heads on the
models western boundary The resulting simulation generally matches
the southeasterly flow direction that is indicated on the
ground-water map (Fig 5)
A3
Legend
x-^- stream 400 = = = unimproved road
I f ee t
Fig 18 Natural Conditions
44
Excavation Without Landfill
The condition of the excavation to the west of Rose Hill Road
with its resultant drainage stream without the landfill was modeled
next (Fig 19) The extent of the excavation ana the location of
the new drainage stream were delineated using the aerial
photograph The west stream elevations were sited in the field and
used in the model The concept of a confining streamoed layer was
excluded in tne excavation drainage stream under the concept tnat no
significant organic layer had been built up within the 25 year
period that the excavation had been initiated Head values between
the west and north stream boundaries were interpolated and input as
constant head values on the northwestern boundary The west
excavation drainage stream creates a condition that alters the
natural ground-water flow patterns by creating a more southerly flow
condition the drainage stream providing a more immediate surface
outflow in that area
Landfill Without Excavation
The hypothetical case of a landfill without the excavation was
modeled next (Fig 20) The low hydraulic conductivity zone of the
landfill changes the natural flow conditions and creates noticeable
mounding This is evidenced by the decreased spacing of the head
contour lines and deviation from the lateral contour lines of the
natural conditions and higher head values (Fig 21)
45
Legend
excava t i on s t ream
400 unimproved road
f e e t
Fig19 Excavat ion without Landfill
46
Legend
landfill limit
bull - s t ream 400 copy WNWNEECSESC
monitoring well locations f ee t bullbull-bull=bull unimproved road
Fig 20 Landfill without Excavation
1
oin CM
bull
m u
0)rf
oO
bullo 9
bullo 9
o rf o o CO 1
lt0inO O
T ^ogt
c o
47
o9 aI 0)
ot_3 O laquolaquo coO bull3 OJ oX
bulla caj
CM
UO|IBAraquo|
48
Landfill ana Excavation
The condition of tne existing landfill and the excavation with
the dam is the next condition modeled (Fig 22) The ground-water
elevations used to calibrate tne model correspond to an actual high
water table condition Between the NVJ and pound weir a streamflow loss
of approximately 102 gpm occurs aoout 60 percent of this flow is
lost at the dam site which maintains a head of b-6 feet over an area
of approximately 1800 feet^ This approximates a field value of
1144 gpm influent to the aduifer between the NW and E weir on ]2
December 1981 (Table 3) From the E weir to the SE weir a net
increase in flow occurred of 74 gpm which corresponds to field
increase of b62 gpm
The surface runoff from tne landfill flows primarily toward tne
eastern side of the landfill Increases in water-table elevations
on the eastern side after heavy rains such as the 11 November 1981
storm indicates that this runoff increases outflow gradients to the
stream and therefore increases streamflow Surface runoff input is
not modeled which explains in part why field stream inflow values
are slightly higher than model predictions especially for periods
after a storm has occurred The flow from the SW weir located at
the southern end of the excavation represents drainage outflows from
that area The net flow calculated in the model was 140 gpm
which approximates field conditions of 1642 gpm on
December 9 1981
49
d f l f reg N E
shy
Legend
landfill limit -bullgt-bullgt- excavation ^-N_X- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road
-40mdash approximate groundwater contour
400
feet
Fig 22 Landfill and Excavation with Dam
50
The modeled flow patterns suggest how the various contamination
zones around the landfill have developed to their present state
They indicate a flow to both the southeast and southwest on their
respective sides of the groundwater divide Evidence of a
southwesterly contaminant flow is presented when the continued high
specific conductance contaminant level in tne observation seepage
hole is realized (Table 5 ) In addition the specific conductance
increase in the west excavation stream is evidence of an influent
contamination flow
Contamination flow to the eastern and southeastern side of the
landfill is obvious High specific conductance levels in the wells
on the eastern side (Table 4 ) a specific conductance increase
between the E and SE weirs (Table 5 ) and contamination in the NE
domestic supply well (Fig 3) present conclusive evidence of
contamination to the eastern side of the landfill
An anamalous condition that exists is a domestic supply well
located approximately 300 feet due south of the landfill remains
uncontaminated (Fig 3) Flow patterns indicate that contamination
would be transported from the landfill south to this area
(Fig 14) One explanation is that a pocket of clay at the southern
end of the landfill area was discovered in the original excavation
for the landfill (lt6) This evidently prevents leachate from
reaching this wells radius of influence
51
Summer Conaitlon
As described earlier during dry months of the year the stream
that normally borders the northern and eastern side of the lanafill
may dry up as far as a point southeast of the E well Tnis
condition existed from the 15 August 1981 to the 27 October 1981
period when streamflow commenced in the northern part of the stream
yet did not overflow the north dam until 17 November 1981 This
created the present day continuous flow condition throughout the
stream These summer conditions were modeled by removing the stream
above the aforementioned location while other conditions remained
the same (Fig 23) Summer condition well water levels listed in the
model generally match field low water table conditions (Fig 9)
Because there is no stream upgradient from the landfill to provide a
stream head and infiltration through the streambed groundwater
runoff from the area north of the lanafill is the controlling flow
input In these moaels an average recharge of 14 inyr was used
which represents a yearly average The summer recnarge conditions
are prooably lower given the effects of decreased rainfall and
increased evapotranspiration during the summer months A domestic
supply well whicn exists northeast of the landfill (Fig 3) nas a
greater potential to be contaminated from the lanafill at tnis time
than when the stream is flowing Flow patterns from the landfill
are such that during an upper stream no-flow condition groundwater
flow patterns are more in an easterly direction than in a
southeasterly direction The stream would act as a source of
infiltrated water upgradient from tne landfill and provide a
52
I ^N gt i I i j i -r- -bull- bullr -T- t- -r- i- TJ JV
bullbullT laquo ^ O - laquo bdquo xi cshy
H r^~ I -~- --^ X- = mdash x^ N
^--^ A bull O^NW -v - gt-bull Ni i I _____mdash - bull laquo l - mdashmdash 1 deg I ^ltv I C
I reg NE A
Js bull vbull A ~ - v T gt- ^ ix - N
-5Z- | N TfS lV I -bull bull iA i gt gt I ^ bullr-Ky L bull 1 _- copy]wgt-- - bull- mdash - - shy
= r Y ~mdash ltmdashA A
^^-lt A _ - - - - bull Hmdash - reg EC x ^-mdash mdash I ---mdash_mdash -t-V-^N - y
I- -bull - r x i X
V ^ 7 I -v (^~~^^r ^^^
sc Emdash-bull vV JI - - - ~ r )N y- -
X - bull r bulllt
^bull^ y y Jlaquo^ - -lt shy
T s^ lt^ ^ +^-b (
X
Legend
landfill limit j-j-bullraquobull excavat ion gt^ -x- s t ream
reg WNWNEECSESC monitoring well locat ions
= == unimproved road fee t
Fig 23 Summer Condition
400
53
constant head across tne northern section of the landfill This
would tend to orient the flow in a more southerly aowngradient
direction In addition the stream which flows adjacent to the
northeastern well could provide a source of infiltrated clean water
to it which would minimize the possible contamination from landfill
leachate
Without Dam
During tne spring scream flow condition the dam failure which
occurred between the 15 March 1982 ana 9 April 1982 monitoring
periods decreased flow to the aauifer and landfill This eliminated
the 5-6 foot head difference over a 19000 ft^ area which had
created a larger area and elevation head for infiltration to occur
The condition without the dam was modeled by reducing the area
encompassed by the dam to a 4 foot wide stream channel thus
reducing the leakance value at that node (Fig 24) The flow change
from the stream to the aduifer between the NW weir and E weir
reduced the model flow loss to 50 gpm Tnis corresponds to the 9
April 1982 monitoring period which indicates a 30 gpm loss
As compared to the previous flow loss in the upper stream
sections to the aauifer the 21 April 1982 and 22 May 1982
measurements between the NW and E weirs indicate a flow gain The
streamflow conditions have changed from an influent
stream-to-aauifer condition to an effluent aduifer-to-stream
condition that increases flow downstream
54
Legend
landfill limit j--i--i- excava t ion x-gtmdash^- stream 400
copy WNWNEECSESC monitoring well locations
= == unimproved road f e e t
Fig 24 Landfill and Excavation without Dam
55
Analysis and Discussion
In order to fully understand flow patterns and Quantify leachate
outflows at the landfill it is necessary to arrive at an estimate
of flow inputs from precipitation ana upgradient sources In the
following analysis it will be demonstrated that the rainfall input
to the landfill is the factor which controls leachate generation A
calculation using the H inyr recharge over the area of the
landfill was made to estimate the leachate outflow due to rainfall
infiltration An estimated 134 gpm is generated from the entire
landfill area Simulation of the existing conditions (Fig 24)
indicates a groundwater divide in the landfill is located
approximately at the western third Therefore approximately 23 of
the generated leachate flows to the eastern side of the landfill or
9 gpm The effect of the flow input from the upgradient stream is
evident when tne summer condition witnout the stream is viewed
(Fig 23) Without the stream to infiltrate the landfill and the
recharge and northern boundary condition as the flow inputs the
head at the northern end of the landfill drops about 5 feet from its
previous value A flow pattern from the north central part of the
landfill to the eastern side indicates a 12 feet head difference
with recharge - but with the upgradient stream a 16 foot head
difference occurs Considering the transmissivity change the
stream would increase the leacnate outflow from the landfill
approximately 43 under a low water table stream influent condition
to the aauifer This would increase leachate outflow to the east
side to approximately 129 gpm This value approximates the
56
outflow at the SE weir location during the summer monitoring period
when the upper stream was not flowing (Table 3) The outflow from
the western third of the landfill whicn lies to the west of the
ground-water divide would be approximately 63 gpm
Realizing the importance of infiltration to tne landfill as a
major influence on the generation of leachate an analysis of this
w i ll be discussed An estimate of infiltration was made using the
precipitation recora for October ana November (Appendix A) During
this time period a minimum of direct evaporation ana
evapotranspiration occured and the grouna is not yet frozen The
top cover over the lanafill is generally 05 ft to 2 ft of local
sandy soil and subsoil availability determined what was used The
top of the landfill is at an elevation of 92 ft as compared to the
ground surface at well W which is at an elevation of 76 ft
(Fig 25) This compares to the well W water level which is at an
elevation of approximately 52 ft This creates a long path for
infiltration through the unsaturated zone The topcover generally
slopes eastwara at a grade of 2-5 The west side maintains a
relatively steep slope of 10-15 ft drop within 50 ft ana the north
and eastern slopes have a more gentle slope of approximately 10 ft
within 100 ft distance An unlined surface arainage swale channels
surface runoff from the northern section of the landfill past the
NE well to the eastern side ana low area in the vicinity of the E
well This has a drainage swale to an area near the stream but
doesnt directly connect to tne stream A poorly graaed drainage
swale exists on the landfills left side The landfill material has
57
excavation
seepage observation ^
hole
Legend bullmdash landfill limit -^--excavation limit r^s- stream
copy WNWNEECSeSCSEN monitoring well locations
--- unimproved road O location of amp Inf i l t rometers O
feet
Fig 25 Infi ltrometer Locat ion and Drainage Feature
58
been placed in 10-12 ft cells and covered with 1 ft of soil at the
end of each day The material has settled differentially creating
areas for depression storage
An estimate of the percentage of precipitation that infiltrates
the landfill was made from precipitation records recorded well
elevations and an estimated specific yield for the landfill
material The volume of water that infiltrated should eaual tne
specific yield multiplied by the well water level rise Several
recharge periods were studied using this relationship Once the
percentage of precipitation that has infiltrated is determined the
percentage that is translated into runoff is simply the remaining
percentage if evaporation is neglected
From the literature for a slightly inclined slope of 2-5
typical runoff coefficients range from 10-20 in either sandy or
heavy soil (16) The landfill cover is generally sloping to the
east which creates a long path (approximately 400 ft) before the
runoff reaches the steeper slope on the eastern side of the landfill
of 15-20 The long drainage distance creates a greater time for
rainfall to infiltrate Another consideration is the actual
capacity of the soil to conauct water into the soil which was tested
in the field using double ring infiltrometers An average initial
percolation of 8 mmhr the first hour and a subseauent rate of b
mmhr occurred (Fig 26) The 8 mmhr rate compares well with
other sandy soil infiltration rates (14) Therefore if the
intensity of the rainfall exceeded a 5 mmhr rate for several hours
59
CO + 09 o
E o
CO
o Z pound C
O
C9
o DC
CO
CD CM
ogt CO N- to -4 CO CM
jq tuu i U O | raquo B J J | | J U |
60
on a poorly drained surface the additional rainfall would be
translated into runoff because the soils infiltration capacity had
been exceeded
The initial 8 mmhr infiltration rate was due to the pore spaces
in the sandy soil being filled and the subsequent 5 mmhr rate was
percolation into the low permeability landfill material The tests
were conducted in November assuming a minimal evapotranspiration
and the field capacity of the sandy soil had been maintainea
The W well was used as representative of the water elevation
changes in the landfill because it is directly adjacent to the
landfill 900 ft distant from the upgradient stream This minimizes
the effect of infiltration from the stream and maintains a high
contaminant level During periods of high runoff conditions excess
surface water ponded in a poorly graded drainage swale on the west
side and directly adjacent to the landfill This influenced the W
well at a time the contamination level dropped (Fig 11) Before
this occurence in mid-December the rise of the W well closely
matches that of the SC well and a background well SK6 which is
located outside the study area (Fig 7) Therefore it was analyzed
as a valia indication of the water level rise during the mid-October
to mid-December period The monitoring of the SC well was
intermittent due to inaccessaoility because of 10 ft extensions
being placed on the well as the refuse was being filled in arouna it
61
A high rainfall period from 14 November 1981 to 1 December 1981
was chosen for the initial study period The effects of
evapotranspiration were neglected due to the cool temperatures
experienced at this time Therefore it was assumed that the field
capacity haa been reachea and tnat any additional input to tne
unsaturated zone would result in direct percolation to tne saturated
zone During the time period 14 November 1981 to 22 November 1981
029 ft of rainfall fell and the well W rose from 488 ft to 493
ft - a 05 ft increase During the next 8 day period there was no
precipitation yet the W well continued to rise to 4972 - a 042 ft
increase The slow percolation of water through the landfill
material would account for the latent rise in the well water level
From previous reports a specific yield for refuse was estimated to
be 028 (1920) This value is dependent on the original compaction
of tne material age and resulting consolidation
During the 14 November 1981 to 1 December 1981 period 029 ft
of rain fell and the well increased 092 ft The following
relationship is used to evaluate the infiltration value and runoff
I = (Sy) h
Sy = specific yield
h = well rise
I = volume infiltrated
I = (028) (092 ft) = 0261 ft
62
The difference between the precipitation and the infiltration is
the runoff (assuming no evapotranspiration) Therefore 029 - 026 =
003 and furthermore 003029 - 13 runoff This corresponds in
the literature to a typical runoff coefficient for an inclined
surface of 2-5
Analyzing a longer precipitation period from 18 October 1981 to
1 December 1981 a net precipitation of 043 ft (accounts for
evaporation) occurred less 10 for runoff or 039 ft infiltrated
This results in a 139 ft elevation increase The well water level
actually increased 132 ft shy only a 5 deviation from the
calculated
From tnis investigation it is seen that a large proportion of
the precipitation has the potential to be transmitted into the
landfills saturated zone Exceptions are wnen heavy precipitation
periods exceed the soil percolation capacity frozen ground prevents
infiltration and direct evaporation and evapotranspiration recycles
the ponded surface water and infiltrated soil moisture back to the
atmosphere In retrospect water temperatures within the monitoring
wells could have been measured to indicate thermal effects from the
landfill on ground-water temperature Ground-water temperatures
were assumed to be 50deg F (9)
63
Specific conductance measurements serve as an indication of
contamination levels These measurements are used to trace leachate
movement which represents ground-water flow patterns Factors which
must be considered when monitoring pollutants are the attenuation of
the leachate contaminants which occurs both in the zone of aeration
and the saturated zone The former is a more complete process
Dilution dispersion and cation exchange are the primary factors
involved in decreasing leachate concentration in the saturated
zone The glacial outwash materials of southern Rhode Island do not
have a cation exchange capacity or a high buffering capacity so
attenuation is simply by dilution and dispersion (22)
The NW well consistently exhibits relatively low specific
conductance levels even though it is in landfill material It is
situated in a drainage swale and ground water elevations range from
543 to 5944 This is several feet below the upgradient stream
elevation of 64 feet which is less than 400 feet away The bottom
of the wellpoint is at an elevation of 5312 feet well into the
landfill material Infiltration from the stream to the landfill has
occurred at this location
The W well is situated on a bedrock high adjacent to the
landfill approximately 900 feet from the upgradient stream and its
water level is higher in elevation than the excavated pit (West
Observation Hole) which is 300 feet directly west The W well
maintains a contaminated level A poorly graded drainage swale to
the west of the landfill provides areas for extensive ponding and
infiltration to occur which explains the drop in conductance after
a high runoff period
64
The SC well is located in landfill material and has a
conductance of over 8000 umhos This indicates that leachate is
undiluted The oottom of the wellpoint is at an elevation of 389
feet which is situated in the landfill material
High specific conductance measurements in the west observation
hole and well W and their relative elevations indicate a
west-southwesterly flow direction from the landfill Infiltration
recharge and leakance from the stream into the landfill provides the
necessary elevation to cause outflow in this direction
Contamination from the landfill to the surrounding streams is
evident (Table 4) During the period 15 August 1981 to 27 Octooer
1981 there was no flow in the stream that Borders the northern and
eastern side of the landfill until a point just south of the E well
was reached High specific conductance levels in the EC and NE
wells were recorded (1000 jjmnos) At a point directly east of well
EC a pool of water existed that was relatively uncontaminated which
is designated as the East Stream] location (Fig 10) At a point
just south of that (East Stream^ polluted water in the streambed
was flowing at a low rate This was measured at the SE weir
location and which had a high conductance also Flowrates varied
between 6 and 23 gpm and specific conductances were over 350
pmhos This low water table condition flowrate is the baseflow from
the eastern side of the landfill and indicates a southeasterly flow
direction from it
Streamflow commenced in tne northern part of the stream 21
October 1931 and the north dam oegan to f i l l Stream specific
65
conductances were low indicating a clean water source Tnis
continued until 17 November 1981 when the dam overflowed ana flow
throughout the east stream began A weir was placed at the Rose
Hill Road NW location and was compared to flowrates at the SE
location Flowrates decreased and specific conductances increased
between these two locations
To further investigate the condition of a lower flowrate
downstream than upstream an intermediate weir was placed at the E
weir location (Fig 9) This snowed tnat the stream from the M
weir to the E weir was losing water to the aauifer (influent
condition) and gaining water at the SE weir (effluent condition)
The condition of a net loss of water between the NW and SE weirs
remained until 19 December 1981 when a snowmelt rain condition
caused increased surface runoff and a net increase in flow at the SE
location Upon analyzing the March and April 1982 streamflow
conditions the expected case of a net ground-water pickup from the
E to SE weir continued The explanation for tne initial net loss of
ground-water is the fact that the leakance from the upstream section
was being discharged into aauifer storage to raise the ground-water
table to an eduilibrium level Upon reaching a high recharge
equilibrium steady state condition any additional input will
eventually be transmitted as baseflow out of the landfill and a
downstream net pickup will occur A hign water table condition
prevailed during the January through May period maintaining this
condition In April the north dam broke through reducing the head
in that area by 4-6 feet The 9 April 1982 monitoring revealed that
66
an influent condition remained between the NW and E weirs but at a
reduced rate The 21 April lower stream flow condition shows a
small pickup of water between the NW and E weirs indicating the nigh
water table and low stream flow conaitions combined with the absence
of the dam had changed the conditions to an effluent condition
This was evident in the May monitoring period
Evidence of contamination on both the western and eastern sides
of the landfill supports the existence of a ground-water divide in
the landfill The west stream which drains the excavated area to
the west of Rose Hill Road shows contamination pickup between its
northern section and the SW weir The W well and ooservation hole
indicate high contamination levels which reinforces the concept of a
contaminant outflow to tne west excavation stream
As shown previously flow towara the eastern side of the
landfill is evident from the nign specific conductances and specific
conductances increases in the stream This is especially evident
during low flow conditions when the stream starts at a point to the
east of the landfill and flows with high specific conductance levels
From the literature a relationship between specific conductance
and dissolved solids exists the dissolved solids (mg1) are
approximately equal to the specific conductance times a factor
ranging between 55 and 09 (39) in this case it is taken as
065 (41) The dissolved solids increase coupled with the stream
flow increases provides a basis of calculating the dissolved solids
outflow to tne stream This calculation method was used in a
previous study (26)
67
The relationship
=Cinout Coutflow Qoutflow - Cupstream Qupstream Qinput
where the numerator is the streamflow pickup and the C- and
Q-jnput is the concentration and flow input from the ground-water
This can be used to estimate dilution level outflows from the
landfill Initially this is used for the ambient ground-water
pickup between the E weir and the SE weir This entire flow doesnt
come from tne lanafill but much of it is conaucted in the high
transmissivity area between the lanafill and stream from upstream
leaxage ana surficial recharge Tnis is evident when this section
of the flow pattern is analyzed on Fig 22 Therefore the landfill
outflow is mixed with tne ambient groundwater flow which dilutes the
landfill leachate before it enters the stream To illustrate-this
concept a calculation using the 9 December 1981 monitoring is used
At this time a flow of 672 gpm occurred at the SE weir with a
specific conductance increase of 7 ymhos between the E and SE
weirs The dissolved solids increase would be approximately 795
Today in tne stream
Where
Co = 90 jumho at SE weir
Qo = 672 gpm at SE weir
Cus = 83 jumho at E weir
Qus = 606 gpm at E weir
Qinput = 66 gpm gain
Cinput = 154 jumho
68
The 154 jumho value represents the contaminant level in the
ground-water adjacent to the landfill
This relationship is applied to approximate the concentration
level dilution in the ambient ground-water between the landfill and
stream The aforementioned relationsnip is in turn applied to the
landfill outflow into the ambient ground-water flow adjacent to the
landfill The ground-water receives landfill leachate dilutes it
and then transmits it to the stream The previously calculated
value of 129 gpm was used as the outflow from the landfill
Co 154 jumho flows into stream
Qo = 67 gpm flow into stream
Cus = 83 jumho background level
Qus = 67 gpm - 129 gpm = 541 gpm
Qinput = 129 gpm from landfill
Cinput = 451 jumhos
Approximately tne same contaminant levels from the landfill (tbl
umho) are arrived at as existed in the summer streamflow conditions
when the upgradient ground-water flow adjacent to the landfill was
at a minimum
In addition to using specific conductance to define
contamination zones electrical resistivity can be used to indicate
contaminated areas The measured earth resistivity is inversely
proportional to the conductivity of ground-water Water containing
contaminants with high ionic concentrations are more electrically
conductive and will have lower resistivity values than surrounding
natural ground water Therefore resistivity methods can be used to
69
delineate plumes of contaminated ground-water that have hign
specific conductances This has been demonstrated by several
investigations (11122328374045)
In this study a Schlumberger vertical electrical sounding R-l
was made in an area of known contamination at the W well (Fig 12)
Given the geologic constraints provided by the well boring log a 4
layer computer model was used to match field survey values A
Schlumberger sounding R-2 in an uncontaminated area north of the
landfill in the same geologic setting was used to provide a
comparison background sounding (Fig 12) A seismic survey N-4 was
made to obtain water table depth and depth to bedrock as input
parameters to a four layer resistivity model (Fig 8) Tne results
of the electrical soundings have been tabulated in Table 6 and
plotted in Fig 27 and 28 respectively
The ascending portion of the field Schlumberger curves were
initially matched using a two-layer ascending type master curve to
provide an approximate depth and apparent resistivity of the
overburdened topsoil layer (8) Tne second unsaturated layers
apparent resistivity was determined by using the graphical
interpretation of total transverse resistance The total transverse
resistance is approximately eoual to the peak value of the curve
times the corresponding Ab2 distance it occurred at This in turn
is eaual to the sum of the first two layers apparent resistivity
times their corresponding layer depths
70
bullH
OJ bull bullH 4J CO CM
c ce G bullrH
j-gt ca c c a 3 ltu O L
co CO 0
bullo Q bull laquos c n 3 -U OrH f~ 3 bO ltn y CO O cc CO ^mdashN
QQ bull
bO bOJJ C C Ci_i
O l T i O O O O O O O O O O O O O O O O bullH bullH mdash^ bullo 0 C c3 f| 3 O raquo O CO CQ
CO
rH
CO O
L 4J
^ltU
i- 1 ^n ^b O 4-) bull2 CM bullH C OJ 1 -U bullH CO C L O a ^-^ 0) a
rH c a L CD ltu (1) 3 tlt bO cO I
3 a 0) a Q 4J laquoa e CO 3 (H bO c C O bullH
CO TJ C 3 bull
bull O bO -i-3
0 CO C O3- O G O O O O O O O O O O O O O O O O O O ft rt1 -raquo - t l S^ ft tfigt f I mdash^ K_ l_ raquo mdash I gt fgt I l 1
(1) 0 rH CO CJ JD o^^ CO CO CQH lts
71
Legend
A actual field measurement
-e- interpretat ion
10000 bull
6000 bull 5000
4000-
3000shy
pound2000| ltD
_ r 1000
09
5 600 pound 500 - 400
I 300 a a lt 200
100 10
Fig 27
20 30 4050 100
Distance AB2
Schlumberger Sounding
200
feet
R-1
400 600
72
loooot
6000 5000 4000
3000+
laquo2000 e
r 1000
raquo 600 pound 600 ~ 400
$ 300 a a lt 200
100
Legend
A actual field measurement
-Qmdashinterpretation
10 20 30 40 50 100 200 400 600 Distance AB2 feet
Fig 28 Schlumberger Sounding R-2
73
Formula T = f
Background Sounding (9000)(15) = (3110j (1 7) + gt2(8)
= 16214 n- ft
W Wel l Sounding (b200)(60) = (500) (2) + pound2(28)
= 13250 SL- ft
To determine a resistivityp3 value for the third layer a
graphical interpretation for the longitudinal conductance S was
used(48) This is eaual to the sum of each individual layers depth
divided by their apparent resistivity
Formula S = -r1 +~r-raquobull-ra
Background Sounding 0017 = yyg + ~^
= IbOU - ft
W Well Sounding 0285 raquo -ggg 7^3 J~
= 179 v-ft
These values were input to a program which calculates a
schlumberger sounding curve (47) The theoretical sounding curves
approximately match the field curve as viewed on fig 27 and fig
28 To provide a check on the apparent resistivity of the saturated
layer at the W well the following relationship was applied 1OOOO
= spec-jfic conductance (umhos)
74
At the W well the specific conductance was measured to be 3 00
jmhos at approximately 10degC
Assuming a formation factor of 45 for the glacial outwash (23)
material Archies law is applied to estimate an apparent resistivity
of the third layer (7)
fgt FF x p
A= 45 x 103-n-ft
A= 4G3 JL-ft
This is a reasonable approximation to tne 3i= 179^-ft calculated
analytically from the sounding curve interpretation
75
Remedial Measures
With the analysis of f low patterns and contamination zones
recommendations to minimize the environmental impact of the leachate
can be reviewed The basic technique is to minimize all sources of
water reaching the refuse so that leacnate production is minimized
The oiversion of precipitation by a relatively impermeable cover and
proper channeling of runoff would minimize percolation into landfill
material Caps and seals can be constructed of clays fly ash
soils soil-cement lime stabilized soil memorane liners
bituminous concrete and asphalttar materials (15) Proper
contouring and grading will help minimize infiltration If a soil
cover is used a vegetative cover can be planted which will utilize
some of the infiltrating flow through evapotranspiration losses
during the growing season By minimizing the length of slopes and
providing proper drainage channels tne surface runoff can be
conveyed to a downgradient area outside the recharge zone
Therefore this surface water will not increase leachate production
from the landfill Also by increasing the slope of the cover over
the landfill itself a higher percentage of runoff and lower
infiltration will occur
To minimize upgradient ground-water influx to the landfill an
impermeable subsurface barrier or intercepting trench could be
used Barriers can be made of bentonite slurry-trench cutoff walls
grout curtains or sheet piling cutoff wal ls extending to the bedrocic
or an impervious layer to effectively prevent water passage or
create a head loss that wil l lower the water table In addition an
76
intercepting trench which has a perforated drain at tne lowest part
of the water seepage zone could be used to intercept and divert the
entire flow
These possibilities have been evaluated with the help of the
model to determine workable solutions for this landfill The
primary concern is to eliminate leachate flows to domestic wells
Initially a simulation was run that eliminated recharge over tne
landfill area (Fig 29) This had a considerable effect on the
ground-water flow patterns of the landfill area The mounding that
had previously occurred under normal recharge conditions was
eliminated and a general drop in the water taole within the landfill
of 2-3 ft occurred The effect of eliminating recnarge over the
landfill when the upper stream is running would cause greater
infiltration from the stream as evidenced by only a 2 ft head loss
in the landfills flow conditions This is evident when comparing
Fig 29 with Fig 24 Tnis indicates that this measure would only
marginally reduce the resultant leachate flow from the landfill
material that lies below the water table In another situation
where there is not such a strong potential for upgradient flow this
measure has proven quite effective (6) In this case the landfill
cover consisted of four layers an intermediate sand and gravel
cover immediately above tne regraded waste materials a 4 inch sana
bed designed to protect the overlying membrane a ilO mil flexible
PVC membrane and an 18 inch final cover of sand and gravel
77
Legend
landfill limit -raquo- -^ -raquobull excava t ion x-^x- s t ream
400 copy WNWNEECSESC monitoring well locations
= -= unimproved road fee t
Fig 29 No Recharge over Landfill
78
Controls such as 10-30 mil polyvinyl chloride covers favor the
development of an anaerobic environment which increases waste
decomposition time and would necessitate installation of gas vents
at several locations on the landfill cover Tne integrity of tne
synthetic cap may be further threatened by subsidence which create
differential stresses on liners Settlement would create areas for
ponding and depression storage and eventually necessitate regrading
the landfill surface The landfills south-central area has oeen
filled within the last year and will prooably need to be regraded
due to settlement within the next few years
Another possibility for a liner would be a soil-bentonite
cover A layered cover consisting of natural materials with low
permeabilities such as bentonite clay followed by a layer of highly
permeable material such as sand and finally a layer of topsoil can
be used Due to potential drying out and cracking of the clay liner
a synthetic liner is the preferred method
The most immediate technique is to grade contour and vegetate
the landfill cover which has been done at this site Althougn an
impermeable cover would probaoly reduce the amount of leachate
produced it would not eliminate the upgradient flow and provide
guaranteed protection of wells in the vicinity of the landfills
northwestern section
A slurry trench along the northwestern perimeter of the landfill
would effectively cutoff upgradient infiltration and divert recharge
infiltration in a southeasterly direction thus removing possible
leachate outflows from the radius of influence of the neighooring
79
wells This has been simulated using the computer moael ana flow
patterns as shown in Fig 30 Contour lines are distorted in the
vicinity of the slurry trench due to the 200 ft nodal spacing
Transmissivity values of 1 ftday were input at the slurry
locations to simulate an impermeable barrier Tne surface recharge
at those nodes does not infiltrate the relatively impermeable grid
nodes at the slurry locations and flows to the edge of the noae
thus creating a dramatic head loss within a short spacing To
effectively simulate this a variable grid spacing should be used
with reduced node grid spacing at trench locations to eliminate
distortion The computer simulation shows that the slurry trench
could direct flow in the landfill area in a southeasterly direction
and away from endangered wells In addition it would reduce
upgradient infiltration from the stream into the landfill This
measure would prevent leachate from spreading beyond this carrier to
possibly contaminate neighboring wells
The combination of both the slurry wall and impermeable cover
would be ideal measures to minimize generation of leachate and to
stop its spread to neighboring wells The slurry wall without
recharge over it or the landfill is simulated in Fig 31 This
indicates a lower water table tnan eliminating the recharge to the
landfill The slurry wall has blocked upgradient ground-water flow
at its location to the landfill
80
Legend
landfill limit -laquo- j -laquobull excava t ion ^^- stream
copy WNWNEECSESC monitoring well locations
= = = unimproved road ssi slurry wall
f e e t
Fig 30 Slurry Wall
81
Legend
landfill limit j- j- J- excavat ion x-v^gt- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road s==s slurry wall
400
feet
Fig 31 Slurry Wall without Recharge Over It or Landfill
82
An intercepting drainage trench is considered next If a trench
was excavated to a 30 ft depth in the outwash material extensive
shoring would be required In addition difficulties would arise
when the trench was excavated below the waterline Tne trench would
be sloped to provide drainage and backfilled with a highly pervious
material to intercept and divert leacnate locally a conouit which
is perforated on the top to allow infiltration and unperforated on
its lower perimeter to permit continuous drainage to the collection
treatment center would be installed on the bottom of the graded
trench The difficulties involved in excavating below the water
table ano shoring the sidewalls to permit implacement of a drainage
conduit at a 30 foot depth make this option increasingly infeasible
83
Conclusions and Recommendations
The location of the South Kingstown landfill in permeable sand
and gravel glacial outwash material (107 ftday) combined with the
high hydraulic gradient across the landfill area (20 ft1600 ft)
creates a high potential for ground-water contamination to occur
This is intensified because refuse nas been placed below the water
table The low hydraulic conductivity of the compacted refuse (1
ftday) and the excavated area to the west of Rose Hill Road have
both contributed to modifying the original southeasterly flow
pattern These modifications have created a ground-water divide in
the landfill at approximately the western third section Tnis
results in approximately 13 of the leachate flow from the landfill
or 63 gpm flowing in a southwesterly direction and 23 or 129
gpm flows in a southeasterly direction Infiltration from
precipitation recnarge over the landfill (up to 9Upound) and from tne
upgradient stream during low water-table periods provides tne
necessary influx into the landfill Evidence of contamination is
clearly seen on both the east and west sides of the landfill which
reinforces the previously stated flow patterns
Of the several remedial measures reviewed the contouring and
grading of the landfill topcover and drainage swale provides the
most immediate protection The topcover has been graded mulched
and seeded to provide a low runoff slope generally to the east
The drainage swale on the left side of the landfill has improperly
graded sections which should be corrected Its northern section
could be drained into the northern sections swale and the southern
84
section drained to the southeastern section of the landfill Tne
point of the drainage swale which divides the northern drainage
swale from the southern one should be determined by a field survey
Cost is a major contributing factor when determining which
remedial measure is to be applied to the given situation For the
purpose of this report cost estimates are not presented but rather
the effectiveness and feasibility of the remedial measures are tne
primary considerations As was reviewed and simulated in the
computer models the slurry trench and impermeable cover over the
landfill are two viable options that would effectively provide
protection to the domestic supply wells in tne vicinity The
impermeable cover would eliminate precipitation recharge into tne
landfill yet drop the water table only a few feet due to upgradient
infiltration from the stream This would decrease the hydraulic
gradient thus diminishing the potential for a contaminant outflow to
surrounding wells The supply well of primary concern is one to the
west of Rose Hi l l Road marked well D on Fig 2 If contamination
occurs in this well the most effective measure would be to block
off leachate flow in this direction by installing a bentonite slurry
trench at the location indicated previously This would effectively
prevent leachate flow in the westerly direction and diverts it to a
more southeasterly direction In addition the slurry trench
precludes infiltration flow into the landfill from the upgradient
stream
85
Tnis report has effectively reviewed tne original ana existing
flow conditions and contaminant levels in the vicinity of the Rose
Hill landfill The purpose was to provide an understanding of
ground-water contamination patterns and study possiole remedial
measures
86lt
Appendix A
Precipitation Records
Monthly normal precipitation 1941 -197O
i$l Total monthly precipitation
KINGSTON RI
14
ia
^JO T I bullbullL
pound 111 laquobull
4
a
n
-
^
-
-
KS1JAN
^Ii R3 HB MAR
1
1 APR MAY
1
1 JUN
1981
JUL
-bullraquolaquo H
AUO SEP
K3~~f$s bull
_imdash
i1S 1
OCf NOV OtC
171 1 iI1
JAN HB MAR APR MAY
198
Fig 32 Precipitation Record
- - - -
IM 1 MtvJrflgtlgt c ortli-A t lUN I r nraquo rl - -
gt|MO CLIMATOLOQICAL OUSERV ATIONshyr-r bull JK gt raquo - 1
i5fWA I VAPOR Al IOH -bull AIM If MPCRATUM bullF 0 riccipn AT ION UNO IlMf
bull 14 H 14 H mdash Vshy ADDITIONAL DATA IfUAlUS OATt 1 bull raquof bull bull 1 ta
14 Hw rlaquo4 w bullbull bull 1 114 1mdash4 (llrl 1 1 1fl Hll
0 kmdash
Mraquo M4 raquo i T i 4 bullraquo-laquobull i i
Lgt f 1 21 S 1 Hbull - - bullbull -
ltJL 1 2 01 - - _ _ 1
mdash
-
1 12 _ Q I
mdash shy
mdash 4 (C ( - - fVi 1 - 0
1 (1
^ 1
Vvraquolaquo IJ1^ raquo CP O 3L 1 Z - i bull j-t-J
1 J
LH Vb T n 0
1 gt fl oo O ~l 2 L - bull 1 P )laquo jn iP IP - OOI L5L mdash shy
-t 84 ^(^^ ^fi P i flja 0 JO II 10 tl tcgt 7 J IV wllaquo
h l2L bull 0 lt -_ shy
-id VJ lt 3C 2 ft OOL -mdash
U 71 C1 Sr 2 13 2 nl JLJraquopound HP r M ltf1- (
IMe 2 ii O It
n jlt dl 1 1 bull o o-il ST i 1 i 25 2-x-1
-
ri
i tlL O mdash gtbull bullgtlt 1ft -o- is Oil So iJK 2-io otv u 31 fil loi 2 il Oll it Of wr is i1raquo -iZ 1 deg|0 01
M IT So - mdash
- 13 1 CT mdash i - mdash 21
shy
Tl Ci av ZUll IMT 0 IM Pe v _ 1) T) S) ii3( dlt Ii 2 lt^2 II li- S1 riivi To 7HX lt3lO 14 ^2- iTi I li 011 -- - -i -^IS no 5^ or i | T Jift laquoV OoH bullla It Va iCO mdash L OIL 11 bullvf poundgtpound lS_ flv oh P-lfe 1 poif _ shy11 IB kl (4 itlaquoT lamp llt0 oot^
mdash -n
It T1 |ir( L1 HI 2 0 oil
U 1M ft go C ICf^ -^2 Z laquo-|o
11 it 5 bulln - TO o abull Li u-i IT1 -- Iw O ltM (I bullbull bdquo-I(K 1mdash -tilltLlA ttfe
i Dgt ac -- U 44 4 11 1 1- ytd i i_i J-K 0 i if -i i i V t Wl raquoOHM 1-1 US D C P A R T M f N T OF COMMfRCE t 4 1 IUII 1 1 ^~) mdash
llaquo- Hi NC bull bullh bull bullJL^V HBl CO 00
11
)jLsVyr^gturv
^ | TKu
|-_t_ bull(
IIMgt I I Mt|UU III- II 11
PNECIPITATIOH
I 1 1 IMX
IMO
bull llfclaquo I UCIUKI) Ur C V A r U M A AHO CLIMATOUOCICAL OBitH
E V A F O R A T I C r i Jttffl laquo amp hMIlaquoJllaquoJIIlaquoBgt
DATE AOOITIOMAL DAIAKMAKk M
bullraquobullmdashlaquo
tp 01 (1 Of Ll OOI ooo
0^1 o-i 10 tl |00 102
OC (1 13 Ofl
it i rc DS os an
(1 SV o
Ul 010
(ISl 101 I on
130
II 5= Otl
ss lt 001 (IK Ml
jt il HIT
7 it
ow Wo 17 Top 2-01 OIO
(0 oov zi oot
u CO ^A 0 to Zoi CLflS
bull50 01 ljtj
nshy 5H LO OIt
50121 IVO QJO
14 Co Ho LO Hl ^pound Jl 1
ltM ool fllc
H Tl 01 II
11 11 Q1
iH OIO
HO 2 llaquol 11 II
lifc
IV-IIM ul OIPAITHINT or COHMIICC NOAA
NAtlOHAL gtIATnlaquoll raquotraquoVlClaquo CD
r~
All TCUMMATUNI ^V UII rgt ITmi 1 Cwphu Obic i gtn t ngir-H 30
rilCiriTATIOH
JJ T I rTJ-rimdashr-iramj|MP CLmATOLOQ
laquolaquo jftilCiii bullIHO
Oi1l ADOITIOHAL DAIAlllu
Ilf4ft
Sii1
(1 2 IO OO
Hl ii SO
us OIM
Q^L
a A3 Hi SZ Sf^ bull 12J2
HI Z-SF OOl 1C t HM IA H ICP fiJA
OOl 10 (310 sn 310
if HI (0 ^01
bullit SO 28H poundJ1 11 006
14 35 TX oon II (bull2 it zr II c-S
rr Zll lo 31 OP an 31 a 31 oor
CSW O-ll Si CC Of 011
Oll _ I |ft
00
u i oerraquolaquoTMiMr of c NOAA
NATIONAL K C A T N C M SCMVlCC
TC^S lk)oiVroTJA
TETT I 7X
1raquolaquolaquo 4 bdquo ir lt er ni I^OV ltqgl j--^ TQ
MICiriTAllOH ITIND
D|mdash
b5NO ctiUATOtoiCAL oeit^
OATI AOOITIOMAL OATAVlHAtt
0-tt
Mlaquoh bullbullbull- rshy laquo
I- ltltriu HI I 4 bulllaquobullbull1
Zii
30 Dfellt otvt
at HA
OOI
62
iJ_S2 HI if
bull- 20 SI 2i So
So
VVfr
OSfc
I (
Jtlt
3aoi
r j -bull ie MA
Irill iiol
in^ 14
Mo
Zll
214
21 1P
00-i
bulliron
17
bullr
11 i ir- I J Ktf^c
US D E P A R T M E N T OF COuMEDCC I | C gt A A
K AIlaquo Ttupf lATuit r
|SlVi AlJ PIICIPITATION
oJud (El
VIM i Uraquo
MIND E
EVAPORATIOH flnrft bull A ftufiifccdll
KECORO OF eVAPllHAtlil bull I CLIHATOLOOCAL OBSERVA ^Hij
14 MM A_M AOOIIIONAL DATA11 MAIM
Mr bullH Oo|
M Si lift
bull221 IHI
ZS Ji 40 IZV
icr KS I
HZ 111
bullT 21
loA UK JA IP
v^ ft
1M 2Sshy IT Tl
71 V |
i I 31 1deg a
uty^ U bull3
ons 1 CiO TxX
HHO (10
3H 19 12 10 IP
raquo3H raquo | 5t io
OP OIT
14
vO UI Of PANTMINI Or COMMCRCf MM O A A
F ngt TIHH
iiicffwiffc 4 rJ (TIM bull Cempltit Obitittiio
AIlaquo TIMHIATUM PHICinTATION I V A f OK ATlPrl
OATI ADDITIONAL DATA KMAlIt
U4laquo4 +
03H Ji
10
rc a 1 16 oi ii
tiiy 10
OI
II i23 or o 13 -y~ou HO
II 3V III i 3 t
V laquop oot
OM1 SS ne
T an -i IP
Olt zr LTV
3T 001
a -11 2T
10 an 31
-1 raquo 131 UP 3H lf 14 Lpoundshy
it 14 30
IS
Ui O I P A K T M f H T OP COWlf ICfM O A A
NATJONAI V C A T M C n f t K M V l C K
bullbullbullbullbullshy -2 o AIlaquo TIMMRATUM f fKICIPITATIOH
OATI poundt- MMINMAL DATAk
ZP 51 lo icr
011 111
OoT IHf
Ut 003 am
3o 13 ao
4A X 05shy
H4 i IjJyiV131 ooc js
IH oi 01 tL 18 13 a
No 11-7
rivgtp OO| M Hi 03 01
It 12
bull I 41 bull7119 14 ^^ raquo 31 15 lampk n M ho i
Jo -j-
-J
I
Ml H^ I _
amp2ampUi^= LS 0 S 0-f bullTTT
-Vmdash gt U_ bull 1 rOHM I- 11 OI OCPARTMlNT OF COMM(NCC
HO NATIONAL W f A T M f H ftfraquoVlCI
98
Appendix B
Boring Logs
99
X iHECT 1 ff 2
OAT American Drilling amp Bor ini I Co Inc
wo WATH smn EAST PR ov IDENC E ft 1 Town of South Kingstown South K ngstown R I MOLENO X-J
TC 100 RCSS bull ujrMonitorinq Well Installation | South Kinqjtown R I UNC a STA Pf KXICCTHJ LOC ATK3N
bull cfrserrr TO above S MPLES S FNTTO _ _ |laquolaquor A-109 SURF ELEV RE PORTSEr
GROUND WATER O6SE RVATC MS 1 CDREraquolaquo m-T nn75 laquo A 256 - 20 mdash Hew y
Instolled 32ofT-l2 PV C - JO- COMPUTE 111275 K toia 3- I-WI 1-38 TOTAL MRS bdquo10 screen BORING FCACUAM J K lanq MAI rraquo HomnwWI 300 140 IampPCCrc Mamlaquor Fall 24 30 lampaaiona SOLS ENGR
LOCATION OF BORING H ONITOKING WELL
Coung Samplt Tjp Blow per 6 Manure SOU IDENTIFICATION Strata SAMPLE ^^^yV Bloot
foot
Otptni
From- To
el
l
on Sampler
0-6 1 -6-13 12-18
Dentity or
Conmt j
Chang Remark include colo^ graaation Type of tod lie Rao-coMr type condition nordshynetiDntotf time leamt and tie No Pen Rtlt
2 No top sample 5 12
1 loamy fine sand
bull)^ 40 30 36
5- 616 0 23 20 16
noist iense
Brown fine to coarse SAND some fine to coarse gravel Trace silt
^
1 18 18
36 8-0shy57 40 30 V 35
|0-||-6 D 14 24 20 Srown medium to coarse SAND Some fine gravel cobbles
7 IRshy 16
27 75 37 3
IS- I- D 5 14 16 3bull
ISshy 15
42 50 I9--0shy50 65 20-2ll-6 D 9 23 26 bull Jrown fine to coarse SAND Tbullwshy 1Z 75 90
22-0 Trace silt trace fine gravel
124 120 74 60 52 41
7S-ltlaquoil-A DX 71 16 13 wet very dense
Gray-brown fine to coarse SANC Some fine to coarse gravel little silt
H IR u
40 30--0
3C-30-IO
3l4-334
334-3314
38 4-434
D
c
C
C
7 IflO
94 6
we tr j
y se
ft irox
30MOshy
31 -4shy
Gray-brown fine to coarse SAND Trace silt
Gray-brown fine SAND some lilt trace fine gravel
Too of Rock 31 -4shy
Gray-pink GRANITE
6 7
amp
CJ
IltJ A
60
601
IQ mdash
2(
4
5 i Hard
ft 5ome seams bull
GROUND SURFACE TO J 4 U3CD_ ^JVrf bullbull( tutu t to 4o 4 SampM Type Proportion UMd MOB Wtx 3 OfaM on 2OD Sampler SUMMARY-
OOry CCartd WltWen4 Hoc OlolO Canmonieraquoi Don any CoKeem CarMWncy Earm Barrlaquoj 11 14
UPgtUnOigtturod Piuon trite (Oto20dego 0-Kgt Loei it 0-4 Sait 3O+Hofd Rock Corng 14 Kgt-30 laquo4 0 rte 4-8 MSHM Samplet TPTtitPit Ai Auger Vvanefett tarn 2Olo39 3O-M Owlt n laquo-lS Strlf rinit nn v 1
UTiUndlshffbed ThrMOll and bull 33to9O 5O Very 0laquo nraquoe 19-30 V-3trraquof - | OLE NO X-l
TOVH rim - iA it raquotoraquo
100
SHEET 2 o_L
WO WATEt STUET [AST ft OVIDENC pound a i American Drilling amp Bor ing Co Inc
MCLl WQ X- 1 Tt AOORCSS i
LIME A STA KXICCTMJ tuf same as 1 | tame as i LOCATION
W PORTSEf mo OB nj urt eflaquo T
illtPLES S
P
CVTTO nlaquo mun orv
^s f^ Tin i GRCVMO WATER OBSERVATONS CASING SAMPLER CORE BAR
START Typi COMPUTE tome at 1 same aiH
TOTAL MRS BORIMG FOR CMAN n bull IT INSPECTOR SOILS EMM
LOCATION OF BORING u HfVJTneTfi UFI _
8
Counf Blo-t
foot
Dtpllo
From To
0( on SampMr
0-6 f 6-IZ
Moittir
Oonuty or
Contilt
Strata Ctnngc
SOIL OCNTiriCATION Rtmorkt ineHifl cotot grqdotion Typlaquo of Mil etc Roo-axtrPlaquo condition Mrdshynlaquot Drog tun ttomt end tic
SAMPLE
No Ptfl RfK
434-4o4 c
approx 7 minj
per toot 454
Gray pink GRANITE Hard Fairly solid core
lt_4 24
Bottom of Boring 45 -4
-
~
bull 1
GROUND Sorrow Tye
SURHCZ 10
bull OiOry CgtCord WWothod UPUnditiurMd Piston TPlaquoTtraquotPtt AtAuotr VVor
UTltUndinrvd TTMMO bull bulltat
iivnPilaquo(onioni Uraquot4
me OioiOItttt laquoraquo20
wmt Z0ie33
and 361090
c M
C1 5 Si
-SOshy
ASING
IOtgtWtigt bullnlot Dn 10 Loci M Mod 04 SO Dm 1shy Viry 0laquo
s _
TMEN 0 hMl on 200 SoiTBUr laquoity ConcMMt Conorawncy gtbull 0-4 Sort 30shym 4-B MStlfl M BH9 Strtf bull ts-so v-swt bull
t-HOrt Ear Bern RoetCorrt
i ^^^^^ bull
-[MOLE no x-i
101
raquoMEC rAmerican Drilling amp Bor in g Co Inc 1 ofj_ DATE wo WATlaquo smn UST Plaquo IOIDCNC j laquo i
Town of South Kingstown South Kingstown 8 MOLE MO Jlt Z TC rx MCS3
rtprr uAurMonitorina Well Initollation | South KinqitowrxRI UNC A STA P KATIOM ME POCT ^rwT TO above I OFFSZT
uD^r laquorlaquorTTO 6 -109 suw tLEv Sgt louffJOCNO
0 tj Tlmlaquo WOUND WATER 06SCRVATC US gtW Rsdl SING SAM^EH CORE BAH
26 ^_ 12 $TAlaquoT UL 2Z2i Ji r TTP NW ltA sr IJZC Z5 CCOMPLETE
SitLO 3 I-3B- 1-38 TOTAL MAS 41 BOAINO FOACMAN JK1 ana nf ni n MonwwWl 300^ 140 BIT bullK^CT
gttonvrar Foil J^laquo 30mdash Diamond SOOJIEMGM
IE HFII
iCaunq SampM Trplaquo BMMtpw6 UOIIIK- SOIL DCMTIFKATION Siraia SAUPLE Blow DlaquoPIAraquo of on SompMr HtmorU mcJuo cotes gradation Type of Dwuily
pw or CXang writK Roel-eolorlyp condition tvort-From- To Vfoot 0-6 f 6-2 12-18 Coniitt egt rwtiOnAngtimt wamaondtte No Praquon Rtlt
2 Brown fine SAND little silt 2 2-0shy5 15 18 moist Browi fin to coarse SAND 18 5- 6-6 0 14 25 27 vlaquo Troc fin aravel | 25 wy Ifl 11
dlt tns 35 40 38 moist n in-il-i Lgt U 15 18 ie is li1 Irl IS 31 I2-0
~~43 1
A) Jrown coars to medium SAI MD 48 moist Little fine to coarse gravel
|5-IA-Xlaquo 14 47 41 fn D laquo y Little silt rrqa coarse sane 3 18 I1
68 In IS 44 32 34
n ^n-^i-A- w 2o 19 29 wet 4 la -59 lens ltfO no
25-0 2amp bulllaquo- 77 c BOULDER r[ 4 i
27-0 5X ~W 24 24 bullWar- 5 Ifl irown tine to coarse SAND some
dens 29-0- Fine-coars gravel trace silt
30-3I oxx 30 32 30 moist irown -gray fine SANDiom e 6 l rr Vlaquoy 31 -0 silt trace fine oroveTILL
Bottom of Boring 31 -ampbull shyBent casing -pulled out and moved over 4 - washed amp tJrovlaquo casing to 30 -Installed 3C gtof 1-12- PVC - 10 screen
WOUND SUraquoraquofCE TO 3pound 1 yijfD MW t ASIMC TMCJ laquo olaquorod -bor of borina
SomoU T]Fplaquo ProigtuliOraquoH UMd MIOtgtWLx3Orolt lon2OASanlaquoMr SUUMARY-D=Dry CCorad Wlaquoworaquonraquod bullact OiaiO CanM gnMM Daonty CIMIH Caamraquoci EffW 8or^ 2pt
UPiUnairurMd Pition Itnt laquoM2O O- O UKraquolaquo 0-4 Soft 3O-hHard Roelaquo Corrig o- JO M0mlaquo 4-8 MSNff SOTipM 1 p^ 3O-9O OwgtM bull-IS Slid
TPlaquoTraquojraquoPit AAugtr ViVon mini tamt 20to39 UTtundiifir6d TrwMOtf and JSloSO 50-raquobull Vary 0nlaquo [HOLE NO x-2 B-3O V-3Mf lev rim - IAIT raquosectlaquoraquo
102
300 iu 24
1 UMnii ffi 140 laquo 30
CA1INC tf
gt taWCTf
bull 0gtlaquo i R Cook Jr_ R Millineton1 Wttn
I~
1 VAMtl CtMG
1 W HO-t MO
1 Oraquo 1 laquo0~ twt
L 1 laquo-raquo VfcM^lf [wlaquoraquoCI ^ ^ K3Ot III laquo
0-LS D
5-65 D
LlQ 10-115 D
15-16 Tgt
Lraquo 70-51 n
25-26 D
F
I O-O Ci
A Allstate Drill ins Co vi o i
PROVIDING R 1bull raquoraquo uvraquonn~ N M O M I T O P I N G HE1 _^lt -^ PI-Traquo UJU
CUM Town of South Kineraquotown raquoraquo 1 1TA maoer Propolaquolaquod Sit for Slude Disposal nltn
laquo V-449 iampAAtut i a 138 ort STI bull r 42777 CtOuMO IKVtllON
Cill bdquo 258 DA II MN ru 42777 rilaquolaquodO laquoraquoTti rum 1911
AU1TATI
MMUI1 raquolaquogtlaquolaquo laquoKiO itXHHKraquoriOi of sous MUAHI nMTKlion Ot CMlaquoMC|kOraquort tl CO~VH DXltgt raquomlaquo laquotf IMi COIOI C4l II I 1raquo gtlaquo^ Oraquo 1Ol rC t Xgttgt VtfKOe Craquo Mi 1 ft liMraquoK laquo0^tlaquot nfgt
1-2-1 10 TOP SOIL FINE LIGHT BROWN SAND traclaquo of ilt
16-31-17
22-24-21 100 FINE TO MEDIUM LIGHT GRAY SAND trace of fine gravlaquol and raquopoundLt
lfl-37-34 150 LIGHT BROWN FINE TO MEDIUM SAND little poundinlaquo gravel
21-17-15 200 MEDIUM TO COARSE SAND bullomc fine gravel
12-4-10
265
Observation well installed
NOTE No casing blows taktn
bullbull B-23 ow
^w^ 265 I raquo bull raquolaquo bull I W
11 laquot gtbullraquo Vlaquo 14 W gt_ c-shyji bull alaquo bull jraquo VI laquoHshyw bullbull m raquobullbull D-6 raquo Mshy
bull bull laquo Vshy
1
bull bull
I
103
MAMMII Allstate Drilling Co ulaquorr 1 or 1 FftOVIOCKZ H L traquolS mTArm^S MONITOR NR WEL
VNO wr3JJO__raquoraquou_24__ HCU MO P-74 n iu riBwi Town of Slt7H^ Xirpin
mdash^ laquo0J P 1 1 bull ^n^ciit^o TVlaquow^laquott1 bullraquoit wt 140 nu 30 olaquor fBu lkv Waste Disposal Arcai
MUTAH a V-449 R Cook Jr UMlaquoiigti D 1 38 0t| raquoIJ raquo 5277 rlaquo SUMO luvlaquorv-laquow
mdash 5277 fipe -raquoT pfpm 150
H MCIO IMNTlXAflON Of SOU t(kAIlaquoS rrn 0-laquoraquo
5 -SF 01 w in laquobull -raquo ^ lit
D 1-2-2 TOP SOIL V-1-oraquo
15 IPbull FINE TO MEDIUM LIGHT GRAY SAND AND GRAVEL
5-65 D 37-27-35 some silt
10-11 D 20-14-18
15-165 D i 17-14-14 155
BROWN COARSE TO MEDIUM SAND little fine to coarse gravel trace of silt
20-211 D 4-4-2
230 GRAY BROWN VERY FINE SAND
25-26J D 7-8-9 AND SILT 265 fvarvedl
Observation well installed
NOTE No casing blows taken
wta 10 n uuraquo c^imdashbull IgtM laquolaquobull- B-24 ow ~ 14 ltfc laquoraquobull vlaquo^ M laquobull r O 0 fmtt bull W-L 26 5
-0- CgtCmdashgt bull laquolaquobull mdash laquo 1 - raquoraquo 1 gt 1laquo bull 1 gtraquor to bull mdashbull bull bull bulllaquo I t l~laquo 1lt Uraquo mdashbull ) bull 1 gtbull ft 0~ H laquoy bullM ta bull -IN la laquobull OPUM bull($ IMI
mdash H raquo laquo-bull
104
Appendix C
Calibration of Specific Conductance Meters
105
Specific conductance measurements were made using a beckman RB
338 temperature compensating meter and a YSI rtooel 33 salinity
conductivity temperature meter The YSI meter is not
temperature correcting A formula to compensate for temperature
differences to standardize YSI measurements was used (21)
A long probe for the Beckman meter was used to measure conductivity
in the wells Differences in conductivity between the YSI ana
Beckman meters and the Beckman short and long probes exist These
were calibrated in the laboratory using 001 N and 01 N KC1
solutions Values presented are Beckman short probe values The
Beckman long probe values were reduced by 76 and tne YSI values
were multiplied by 11 to adjust to Beckman short probe values The
YSI meter was used in the latter phases of the study for the
stream contamination due to the greater accuracy of the dial readout
scale
Table 7 Specific Conductance Meter Calibration Table
Concentration (KCL) 0001N 001N
Specific Beckman short 145 143 143 1247 1245 12GO
Conductances Beckman long 190 191 188 1639 1650 1665
umhocm 9 25 C YSI 132 131 128 1131 1140 1150
average values Beckman shortBeckman long = 075
Beckman shortYSI = 11
106
Appendix D
Computer program Flow Chart
107
F1g 33 Computer Program Flow Chart-
1TpoundR MAP TCO
NEWPER
WEWSTP CZAX
HEWIT TRANS TCOF ROW COLUMN
Yes
Yes
108 The following is a description of the USGS two-dimensional computer
program Iterative Digital Model for Aquifer Evaluation updated
December 1972 by P C Trescott The program written in Fortran
consists of a MAIN program and six subprograms or subroutines which
themselves are organized into subprogram sections The subroutines and
their sections are listed below
MAIN Program
DATAIN (subroutine) COEF ITER (section) CLAY MAP TRANS NEWPER TCOF
ETRATE COMPUT STORAG
NEWSTP LEAKAG NEWIT1 NEWITO CHECK ROW CWRITE COLUMN STEADY PRNTA OUTPUT DRY BLOCK DATA
The program begins in the MAIN program which controls the sequence
of passage to the subroutines Sequential steps are described in the
program as shown in the flow chart of Fig 32 Emphasis is placed on the
steady state confined aquifer case as applied in this study First data
input is read in the DATAIN subroutine This data includes transmissivities
or permeabilities starting heads storage coefficients and grid spacings
Nodal transmissivity values are then computed for the water-table problem
in the TRANS section (COEF subroutine) This procedure is necessary here
because the subsequent routine for computing iteration parameters (ITER)
keys on nodal transmissivity values which would not have been input to
the water-table problem In the water-table option these would have been
109
computed from given bedrock and water-table elevations to obtain the
saturated thickness component of the transmissivity calculation In this
study water-table option was not used and the transmissivity values were
input directly The program then passes to the ITER section (DATAIN
subroutine) to compute the iteration parameters which expediate or even
cause convergence Next the MAP section (DATAIN subroutine) is utilized
to initialize data for an alphanumeric map if this was requested in the
input options Transmissivities are then computed for the confined
(artesian) aquifer case (water table not specified with input options)
in the TCOF section (COEF subroutine) These coefficients are harmonic
mean values of adjacent nodal transmissivities weighted by grid sizes
Time parameters and pumping data for a new pumping period are then read
in the NEWPER section (DATAIN subroutine) followed by entry into the
NEWSTP section (COMPUT subroutine) which calculates the size of the
time step Leakage coefficients (hydraulic conductivity of the confining
bed divided by confining bed thickness) are next computed in the CLAY
section (COEF subroutine) if leakage was specified in the input data
which was used in this study
A new iteration is then initiated in sections NEWITO (COMPUT
subroutine) NEWITO saves the current head values and compares them to
the updated head values for determining closure This is followed by
nodal transmissivity values being computed for the water table or water-
table artesian conversion problem Transmissivity coefficients are then
computed for the water-table problem in TCOF (COEF subroutine) Total
head values are then computed with the alternating direction implicit
procedure using the Thomas algorithim first along rows in the ROW section
110 and then along columns in the COLUMN section both in the COMPUT subroutine
Then if a solution is not obtained (because the error criteria for
closure is not satisfied) the MAIN program branches back to NEWIT1 subshy
sequent sections TRANS TCOF ROW and COLUMN repeatedly until a
solution at the particular time step is achieved NEWIT1 increments the
iteration counter and is immediately followed by NEWITO The program then
moves to the STEADY section of the COMPUT subroutine to check if the
closure criteria for steady state has been satisfied Output is then
printed in the OUTPUT section of COMPUT if steady state has been reached
or if the particular time step is designated for output
The program then branches back to NEWSTP (COMPUT subroutine) and
moves through the subsequent routines until the last time step in the
pumping period is reached Output is then promoted in the DRY section
of COMPUT if specified in input data If the last pumping period in
the problem has not been reached the program branches back to the
NEWPER section and moves again through subsequent sections otherwise
the program will terminate or start a new problem if one follows
This study was simulated as a steady state problem which can be
simulated by setting the storage coefficient of the aquifer and the
specific storage of the confining bed to zero and using one time step
of any length
111
Appendix E
Computer Data Sheets
RGSEA
10 ROSE HILL LANDFILL MODEL 20 30 40 LEAKAGE 50 60 70 CHECK 80 90 100 HEAD 110 120 1 23 IQ 100 5 001 37E-OU 0 130 100 001 0 0 1 4 0 - 1 - 1 1 - 1 - 1 i i i i i i 1
ISO 1 10 0 1547E-05 01 10 1 1 160 04642 200 200 1 1 i it
1QO 190
CARDS I THROUGH 19 - CODING SHEET
CHEAD
100 110 120 130 131 132 140 141 142 150 151 152 160 161 162 163 164 165 170 171 172 173 174 175 176 177 178 179 1BO 101 190 191 192
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 539
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 58
25
25
25
25
25
25 621
25
25
25
25
25 662
25 25
25
CARD SET 2 - STARTING HEAD MATRIX (FT)
193 194 IVb 196 197 190 200 201 202 210 211 212 220 221 222 223 bull 224 225 230 231 232 233 234 235 236 237 23B 239 240 241 250 251 252 253 254 255
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 23 25 25 25 25 25
25 25 - 25 25 25 25 25 25 25 25 25- 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 - 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25
25 25
25
25 25
25 25
25 25
25
25 25
25
25 25
25
25
25
25 25
25 25
25
25 25
25 25
25 25
25
25
25 25
25
25 25
CARD SET 2 - STARTING HEAD MATRIX (FT) - continued
STORC 1512 FRI 19 FEB 82
100 110 -1 -1 - 1 - 1 0 0 120 130 140 ISO 160 170 100 190 200 210 220 230 240 230 251 260 261 262 263 270 271
CARD SET 3 - STORAGE COEFFICENT
LEAK
100 110 120 02 130 _ 18 02
I ltu 18140 025 150 02015015015 19 deg25
02 160 022 bull-laquo- J1 5 j 1 z laquo- l^
170 015 180 016 laquo02
190 016 OE025
200 02504019022021025 2 5 i S lt03 0252i2 n
230 030 deg23 deg2 deg2 deg2 -02023023 240 022 250 022025025 02
027043 013025
30() 025025025 310 025031 320 024025
CARD SET 5 - AREA OF STEAMBEDAREA OF NODE
120
Appendix F
Bibliography
121 BIBLIOGRAPHY
1 Agpar MA and 0 Langmuir Ground-Water Pollution Potential of a Landfill Above tne Water Table Groundwater V 9 No 6 1971 pp 76-96
2 Allen William B Hahn GW and RA Brackley Availability of Ground Water Upper Pawcatuck River Basin Rhode Island USGS US Government Printing-office GS 66-624 19bb
3 Annual Book of ASTM Standards Part 31 Open Channel Flow Measurement of Water and Waste Water by Weirs D 2034-68 1975
4 Annual Book of ASTM Standards Part 19 Infiltration Rate of Soils in Field Using Double-Ring Infiltrameters D 3385-75 1975
5 Baeaecner MJ and W BacK Hyarogeological Processes and Chemical Reactions of a Landfill Ground Water V 17 no 5 1979 pp 429-437
6 Beck WW Dunn AL and Grover H Emrich Leachate Quality Improvements After Top Sealing1 8th SHwRD MERL Symposium 1982
7 Beckman WK Transient Modeling For Estimating Sustained Aauifer Yield master thesis presented to the University of Rhode Island Kingston RI 1978
8 Bhattacharya PK and HP Patra Direct Current Geoelectric Sounding Elsevier Publishing Co New York 1968 135 p
9 Bouwer H Ground Water Hydrology McGraw-Hill Book Co New Yoric 1978 p 378
10 Braids 0 Cocozza pound Fenn D Isbister J Rous P and B Yarc Procedures Manual for Ground Water Monitoring at Solid Waste Disposal Facilities Environmental Protection Agency530SW-611 Cincinnati Ohio 1977
11 Cartwright K and MR McComas Geophysical Surveys in the Vicinity of Sanitary Landfills in Northeastern Illinois Groundwater V 6 no 5 1968 pp 23-30
12 Cartwright K and Fd Sherman Jr Electrical Earth Resistivity Surveying in Landfill Investigations Reprinted from Proceedings of ohe lOtn Annual Engineering and Soils Engineering Symposium Moscow Idaho 1972
122 13 Clark TP Survey of Ground-Water Protection Methods for
Illinois Landfills Groundwater V 13 no 4 1975 pp 321-331
14 Dunne T and LB Leapold Water in Environmental Planning WH Freeman and Company San Francisco 1978
15 Faro DG Upgrading Hazardous Waste Disposal Sites Remedial Approaches US Environmental Protection Agency500SW-677 Cincinnati Onio 1978
16 Fenn DG Hanley KJ and TV Degeare Use of the Water Balance Method for Predicting Leachate Generation From Solia Waste Disposal Sites US Environmental Protection Agency530SW-lfa8 Cincinnati Ohio 1975
17 Geisser 0 An Electric Analog and Digital Computer Model of the Chipuxet Ground Water^ Aquifer Kingston Rhode Island master thesis presented to the University of Rhode Island Kingston RI 1975
18 Hahn GW Groundwater Map of the Narragansett Pier Quadrangle Rhode Island Rhode Island Water Resources Coordinating Board GWM 5 1959
19 Hemsley William T Koster C Wallace Remedial Technique of Controlling and Treating Low Volume Leachate Discharge USEPA National Conference on Management of Uncontrolled Hazardous Waste Sites Oct 1980
20 Hughes GM RA Landon and RN Farvolden Hydrogeology of Solid Waste Disposal Sites in Northeastern Illinois Final Report to US Environmental Protection Agency PUD SW-l^d Cincinnati Ohio 1971
21 Keller GV and FC Frischknecht Electrical Methods in Geophysical Prospecting Pergamon Press New YorK NY 19bb
22 Kelly WE West Kingston Landfill An Evaluation of Its Effect on Ground-Water Quality Rnoae Island Water Resources Board Water Information Series Report 1975
23 Kelly WE Geoelectric Sounding for Delineating Ground-Water Contamination Groundwater V 14 No 1 1976 pp fa-10
24 Kelly WE Ground-Water Pollution Near a Landfill ASCE Environmental Engineering Division Journal V 10 No EE6 Dec 19b pp nay-nyy
25 Kelly WE personal communication January 1982
123
26 Kelly WE and OW Urish A Study of the Effects of Salt Storage Practices on Surface ana Ground Water Quality in Rhode Island NTIS FHWA-RI-RD-8001 1981 54 p
27 Kimmel GE and OC Braids Leachate Plumes in a Highly Permeable Aauifer Groundwater y 12 no 6 1974 pp 388-393
28 Klefstaa G Senalein LVA ana RC Palmauist Limitations of the Electrical Resistivity Method in Landfill Investigations Groundwater V 13 No 5 1975 pp 418-427
29 Landon RA Application of Hydrogeology to the Selection of Refuse Disposal Sites Groundwater V 7 no b 19b9 pp 9-13
30 Lang SM Bierschenk WH ana WB Allen 1960 Hyaraulic Characteristics of Glacial Outwash in Rhode Island Rhode Islana Water Resources Coordinating Board Bulletin No 3
31 LeGrand HE Patterns of Contaminated Zones of Water in the Ground Water Resources Research v 1 No 1 1965
32 Palmauist R and L Sendlein The Configuration of Contamination Enclaves from Refuse Disposal Sites on Floodplains Grouna Water v 13 no 2 1975 pp 167-181
33 Pinder GF A Digital Model for Aauifer Evaluation Techniaues of Water Resources Investigations of the US Geological Survey Bk 7 Cl 1970
34 Purushattam D Tamxe GR and CM Stoffel Leachate Production at Sanitary Landfill Sites ASCE Environmental Engineering Division Journal V 103 no EE 6 Dec1977 pp 981-988
35 Remson I Fungaroli AA ana AW Lawrence Water Movement in an Unsaturated Sanitary Landfill ASCE Sanitary Engineering Division Journal v 94 no SA2 April1968 pp 307-316
36 Rosenshien JS Gouthier JB and WB Allen Hydrologic Characteristics and Sustained Yield of Principal Ground-Water Units Potowamut-Wickford Area Rhoae Island USGS US Government Printing Office GS 67-324 1968
37 Roux PH and B Vincent Electrical Resistivity Evaluations At Solid Waste Disposal Facilities US Environmental Protection Agency SW-729 Cincinnati Ohio 1978
124
38 Salvato JA Wi lk ie WG and BE Mead Sanitary Landfill Leaching Prevention and Control Water Pollution Control Federation Journal v 43 no 10 Oct 1971 pp 2084-2100
39 Sawyer CN and PL McCarty Chemistry for Environmental Engineering McGraw Hill 1978
40 Stellar RL and P Roux Earth Resist ivi ty Surveys - A Method for Defining Ground-Water Contamination Ground Water v 13 no 2 1975 pp 145-150
41 Todd OK Ground Water Hydrology John Wi ley and Sons Inc New York 1959
42 Tolman AL Ballestero AP Beck WW and GH Emrich Guidance Mannual For Minimizing Pollution From Waste Disposal Sites US Environmental Protection Agency-500SW-677 Cincinnati Ohio 1978
43 Trescott PC Iterative Digital Model for Aauifer Evaluation US Geological Survey Open file report 1972
44 University of Rhode Island Academic Computer Center CalComp Contouring Manual
45 Warner DL Preliminary Field Studies Using Earth Resistivity Measurements for Delineating Zones of Contaminated Ground Water Groundwater v 7 1969 pp 9-16
46 White EF A Report to the Town of S Kingstown Utility Survey Engineering Corp 1967
47 Zohdy AAR A Computer Program for the Calculation of Schlumberger Sounding Curves Over Horizontally Layered Media Using the Method of Convolution US Geological Survey Denver
48 Zohdy AAR Eaton GP and DR Mabey Application of Surface Geophysics to Ground-Water Investigations Technidues of Water-Resources Investigations of the US Geological Survey Book 2 Chapter 01 Washington US Government Printing Office 2401-02543 1974
VI
List of Tables
Table
1 Well point Water Elevations 17
2 Seismic Refraction Survey Results 20
3 S tream Fl ows 22
4 Specific Conductances in Well points 26
5 Specific Conductances in Streams and Observation Holes 27
6 Schlumberger Vertical Electrical Sounding Results 27
7 Specific Conductance Meter Calibration Table 105
Vl l
List of Figures
Figure
1 Location Map 2
2 Study Area 3
3 SupplyWel l Locations 4
4 Field Grouna-Water Table Contour Map 5
5 Ground-water Map 12
6 Geology Background Map 13
7 Fluctuation in Water Level in W e l l s 16
8 Seismic Survey Location 19
9 We i r Locations and Water Level Ranges 21
10 Surface Contamination Monitoring Locations 24
11 Fluctuation in Specific Conductance in W e l l s 25
12 Electrical Resist iv i ty Sounding Location 28
1 3 Model Grid 31
14 Simulated Ground Water Table Contour Map 32
1 5 Northern Drainage Area 34
16 Landfill West-East Cross-section between Wells W and EC 39
17 Landfill North-South Cross-section between Wells NW and SC40
18 Natural Conditions 43
19 Excavation without Landfill 45
20 Landfill without Excavation 46
21 Landfill Head Contour Cross-section 47
22 Landfill and Excavation with Dam 49
23 Summer Condition 52
24 Landfill ana Excavation without Dam 54
VI 1
25 Infiltrometer Location and Drainage Feature 57
26 Results of Infiltrometer Tests 59
27 Schlumberger Sounding R-l 71
28 Schlumberger Sounding R-2 72
29 No Recharge over Lanafill 77
30 SI urry Wall 80
31 Slurry Wall without Recnarge Over It or Landfill 81
32 Precipitation Record 87
33 Computer Program Flow Chart 107
Introduction
Ground-water contamination of aauifers from municipal landfills
is a widespread problem Contamination of domestic supply wells and
neighboring streams has occured at the South Kingstown municipal
landfill which is located adjacent to Rose H i l l Road approximately
one mile nortn of Peace Dale Rhode Island (Fig 12) The polluted
neighboring wells have been relocated to their present locations to
remove them from tne leacnate plume (Fig 3) Fig 4 inaicates flow
patterns from the landfill which has contaminated streams to the
east and southwest of it The generation of leachate continues as
precipitation recharge and upgradient ground-water sources
infiltrate the refuse To effectively prevent or minimize
contamination from this landfill several remedial options are
available These w i l l be evaluated relative to the areas geologic
setting and hydraulic properties ground-water flow patterns
recharge characteristics and proximity to supply sources
The rate of ground-water flow out of the landfill into the
adjacent aauifer and flow patterns largely depend on tne hydraulic
gradient of the water table and the hydraulic conductivity of the
landfill and aduifer material The hydraulic gradients were
determined by monitoring water-table fluctuations in several wells
located around the landfill and elevation siting in stream
locations and elevations This information enabled a ground-water
map of the area to be developed from where flow patterns can be
developed assuming flow lines are orthogonal to contour lines The
ground-water map in combination with Knowing aquifer and landfill
N
^ooo
feet
Fig 1 Location Map
3
peoy ||H asoa
X ltbull
Alt
f c c
o
^ ^ o o f a
O OJ 83X1
o O
x o
seepage observation -t West
hole Landfill Area
Legend mdash landfill limit bull j--excavation limit r^-s stream copy WNWNEECSeuroSCSEN
monitoring well locations = = = unimproved road
A contaminated domesti supply well
D uncontaminated domestic supply well
feet
Fig 3 Supply Well Locations
5
a 03
N lo ^ gt
laquo c 2
mdash w
3
X o ^
3 O L
o CO
0 opound E bullo
0
co
c
o0
uj ^
0 o o c
o $ bullA
E c o
w
bullo t_hraquo9 O
_OplusmnJ ca
u
pro
ve I 51 H
bullo 0gt
UJ _c e poundbullo Mzbull w gt 0
laquorege cc
0gt -^^ o a5 raquobull bullo o sect 3 mdash laquoo o wcz _
3Ogt c $c o_ X
aw e 05 0 (0 3 bullo
o a 2 2 u
hydraulic properties and the subsurface geometry enable estimates of
ground-water outflow to be made Streamflow measurements were used
to verify these outflows Contamination levels using specific
conductance measurements as an indicator were measured in wells
streams and observation holes to help delineate the extent ana
degree of contamination An electrical resistivity sounding was
conducted in a known contamination zone
The primary objective of tnis study is to determine flow
patterns in the vicinity of the landfill ana recommend possible
actions to contain or minimize the impact of the contamination In
oraer to fully evaluate these goals the aforementioned parameters
were input to a computer model to produce simulated flow patterns
under different conditions The simulated present conditions were
matched with field water table and stream flow measurements to
calibrate the model A series of simulations were then run to
evaluate flow conditions before the excavations anaor landfill
existed Remedial measures such as reducing recharge to the
landfill and implementing a slurry wall to blocx off leachate flow
to endangered wells were simulated to evaluate their effectiveness
Based on this analysis recommendations are made as to how to
minimize leachate production ano best alleviate the immediate danger
of the contaminant plume spreading to unpolluted domestic supply
wells
background
The South Kingstown landfill is in a geologic setting that is
very similiar to the nearby West Kingston landfill This is located
about 3 miles west of the South Kingstown landfill and has been
studied to assess leachate effects on groundwater quality using
specific conductance as an indicator of contamination levels
(222ltt) Both sites were located in abandoned gravel Quarries which
were filled in with refuse to create the landfill
In the literature numerous authors have shown that the character
of contaminant plumes from landfills are largely dependent on the
local geology and geohydrology A study on Long Island (27) in
similiar glacial material illustrates that the Quantity of flow is
dependent on the hydraulic conductivity of tne aauifer the
hydraulic gradient and the vertical cross-sectional area of the
aauifer it flows through This is expressed as Darcys Law (41)
Q = KIA
wnere Q = flow quantity
I = hydraulic gradient
K = hydraulic conductivity of the aauifer
A = vertical cross sectional area of the flow area
Specific conductance was used as a contaminant tracer to show that
the plume from the landfill flowed downgradient and vertically
through the full thickness of the aauifer A study in Iowa (32)
indicates that the size ana shape of the contamination outflow from
a l a n d f i l l can be predicted from existing geohydrologic conditions
and that the horizontal shape of the outflow extends downgradient
8
from the source and parallel to ground-water flow lines Other
parameters which control the extent of the contaminant plume are
dilution and dispersion in the aquifer and the adsorption properties
of the aauifer material (31)
The amount of leachate generated depends largely on the amount
of water that infiltrates through the landfill to increase tne water
content of the refuse in the landfill The precipitation recharge
that percolates down through the unsaturated zone to the water table
moves in a vertical direction (35) Surface runoff soil moisture
storage losses and evapotranspiration account for tne precipitation
that is not transmitted tnrough the unsaturated zone of aeration
(3315) Upon reaching the saturated zone the water enters the
ground-water flow system Ground-water mounding has been reported
in landfills due to the decreased hydraulic conductivity of
compacted refuse relative to surrounding aauifer material (20)
Chemical processes within the landfill leachate outflow and
surrounding soil cation exchange capacity relative to water duality
of the surrounding aduifer have been studied in Pennsylvania (1) anu
in Delaware (5) A procedures manual for ground-water monitoring at
solid waste disposal facilities was developed by the US
Environmental Protection Agency (USEPA) (9)
Several reports have been written that investigate site
selection design criteria and remedial measures to correct
leachate problems (29) A survey of ground-water protection methods
for landfills in Illinois studies relationships to the water table
theory of liner installation and monitoring devices (13) Sanitary
Landfi11-Leaching Prevention and Control presents a review of
preventative methods such as means to minimize infiltration
interception of ground-water and other pollution control measures
(2 37) A study in Pennsylvania on actual measures implemented to
collect and treat a landfills leachate discharge presents a site
specific study (19) Leachate Quality Improvements After Top
Sealing1 shows that by minimizing infiltration at a landfill in
Connecticut the outflow leachate water quality can be improved
dramatically and contamination plume reduced significantly (6) The
most comprehensive reports on remedial approaches to upgrading waste
disposal sites and ground-water protection methods have been
compiled under USEPA contract (1542)
To assist in evaluating remedial measures the US Geological
Survey (USGS) computer model Iterative Digital Model for Aduifer
Evaluation was used It was originally developed as a model for
simulating two-dimensional aauifer problems (33) It had been
updated since its original development to accomodate different
options (43) This model has been applied to glacial outwash
regions in Rhode Island (717)
10
Description of Study Area
A map of tne landfill area (Fig Z) was obtained from tne town
of South Kingstown The excavation to the west of Rose Hill Roaa
the landfill area directly to the east and the presently operating
area to the east of the central stream comprise tne overall study
area This study will concentrate on the west landfill area whicn
has recently reached capacity and been closed to further dumping
This site received mixed refuse for the past 15 years The depth of
the excavation where the landfill presently exists was approximately
to bedrock in some places Tne exact depths of landfill material is
unknown
The landfill cover has been graded and sloped generally eastward
to convey surface runoff to the eastern side A sandy soil that was
excavated locally was used as tne cover material The northern
section has a vegetation cover and the recently filled southern
section has been seeded and mulched The six monitoring wells W
NW NE EC SE SC were placed by the town of South Kingstown to
provide water quality information
Referring to Fig 2 the west excavation stream drains the area
created by the excavation to the west of Rose Hill Road and flows
throughout the year The central stream drains a small watershed
area which lies to the northwest of the landfill and drys up during
part of the year These streams flow into the Saugatucket River
which flows throughout the year and is larger than the west and
central streams combined
11
The USGS Groundwater Map (18) was initially consulted to proviae
information on the ground-water flow patterns (Fig 5) and the
geology of tne area (Fig 6) The surficial geology borings and the
vertical geologic cross-section at the base of the study area
indicate shallow water table and bedrocic and a nearly constant
saturated thickness (18) Boring logs at the W well ana a point
approximately 150 feet south of it indicate glacial outwasn material
which is primarily sana with a trace of gravel over bedrock at a
depth of approximately 33 feet Borings at the east landfill area N
and S monitoring wells indicate the same aquifer material
(Appendix B)
The ground-water map developed by Hahn is taken as
representative of conditions existing prior to the excavation of the
I l andfill (18) This indicates water-table contour lines that run in i
a general northeasterly direction This means tnat flow was
originally in a southeasterly direction However contamination of
domestic supply wells on the west side of Rose Hill Road has
occurred (Fig 3) strongly suggesting that the original flow pattern
has been altered by the excavation to the west of Rose Hill Road and
the landfill to the east of it Domestic supply wells were formerly
located directly to the west of Rose Hill Road but were aoandoned
when they became contaminated from landfill leachate New wells
were located to the south and west away from the contaminant plume
of tne landfill In addition a well located at the northeastern
corner of the landfill was contaminated and a replacement located to
the east of Us former location on tne opposite side of the central
12
Legend scale 124000
mdash-40 mdashground-water contour elevation
Fig 5 Ground-Water Map
13
Legend feet
TILL
Fig 6 Geology Background Map
14
stream This second wel 1 also became contaminated Domestic supply
wells located near tne northwestern corner of tne landfill and
approximately 300 feet south of it nave remained uncontaminated
These well locations serve as an indication of tne extent of the
landfill contamination which is largely dependent on the groundwater
flow patterns To furtner investigate this problem and provide
substantial information on which to base the geohydrologic analysis
field studies of the area were conducted
15
Field Studies ana Procedures
A map of the lanafill and an aerial pnotograph of the area were
obtained A tracing of these maps superimposed upon another
delineates stream landfill and monitor well locations (Fig 2)
The field investigation concentrated on the west landfill area ana
its aajoining streams ana monitor wells The east landfill area and
the three monitor wells in that area are induced in the latter
phase of the study in oraer to expand the model area
A traverse which establishea tne monitor well elevations was run
using a Carl Zeiss level These were originally sitea in by the
town of South Kingstown using a local USGS reference datum number 40
(18) The wells of known elevations then served as benchmarks for
referencing adjacent stream elevations This in combination with
the depth to water table measurements at each well enables tne
water-table surface geometry of the area to oe visualized
Water-table measurements of the west landfills wells were recordea
over a ten month period to record fluctuations (Fig 7 Table 1)
The east landfill areas wells were monitored for a five month
period Using a given water-table condition a ground-water map was
developea of the area (Fig 4) This indicates an outflow from
the landfill primarily in a southeasterly direction and partially
in a southwesterly direction
Additional bedrock and water-table information was ootainea by a
seismic refraction survey at several locations along the landfill
perimeter A Bison Model lb70C Signal Enhancement Seismograpn was
used to maxe the surveys Lines were run (to a length of kOO feet)
16
17
w s p bdquo S bdquo s S S a laquolaquo _
s 2 8
V
r bdquo
3 s a
-R s
S
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t
raquobullraquo
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5
K
r
~
3
K
pound
7
S
bdquo3
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shy raquo S s
1 3 s 3 2 5 ^ bull
5 m
s o
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--
R bull 5
s pound J O s
5 a 3 7 3 m
5 s a ^
iraquo a s rlaquo
M ^
^ c o 2 5 s 3 a S R
rd 3 y a O =J
^ bdquo
JJ s s 3 bull ~ I
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(Ogt (U
2
-t =
r s s in
5 y
a s
5
3
s
5 a
^ a
3 a 51 a bullbull
sj 5 Ml
3 a bull
s raquo
a
0)
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^ mdash
a j -
-3
C
g S
S
bull a
-
~ 3 o
2 s s 3 a bdquo s s $ Al s
(1) = $ s 3
S
c a a
3 e 5 s N s S a - 3 = s s a 5
a s s - 3 S shy
4
0
a s
bdquo tfH
bdquo
3 a
bdquo
s a
e bullfl s i s s a s a
3 nt
s s 3
g laquo s3 a
~ J s 2 a s o s S s 3 a a j laquo s o s
3 bull laquobull
2 a 7 3 a 3 a ^2
s mdash 5i o
bull bull
mdash
3 o
ss a
fc mdash
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18
in both directions to provide a check and permit accurate estimates
of the depth to bedrockThe seismic results allow approximate
interpretations of the depth to the water table and bedrocK thus
permitting an estimation of the saturated thickness Ground
elevations at the location of the seismic surveys were determined
from a topographical map and field siting From this information
water table ana bedrock elevations estimates were made Bedrock
contours are listed in Fig 8 In addition a table which
summarizes the seismic refraction results for the unsaturated
saturated and bedrock layers velocities and depths at each survey
location is presented in Table 2
Scream gauging stations were established on the two streams
bordering the west landfill (Fig 9) Three stations were placed on
the central stream These provide information on the influent or
effluent condition of ground-water flow in the upper sections of the
stream and ground-water baseflow from an area adjacent to the
landfill into the stream (Table 3)
The stream gauging stations used were 90deg V-notch weirs The
weirs located in the SE and SW positions were placed in the
streamoea with a liner of plastic upstream to minimize underflow
The weirs located in the NW and E positions were cut to fit in
recesses of concrete culvert pipes Concrete plywooa interfaces
were coated with roofing cement to minimize bypass flow Upstream
water pressure and a snug fit hold the plywood sections in place
All weirs were implaceo according to AigtTM reouirements and flowrates
calculated using the standard 90deg V-notch formula (3)
19
N
seepage West observat ion Landfill hole
Area
Legend landfill limit excavat ion limit
copyWNWNEECSESC monitoring well locations
= = = unimproved road -- WNES-number
seismic refraction locations
-40shy approximate bedrock contpur elevation
feet
Fig8 Seismte Survey Location
20
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co CM o on on CO CM CTNVO VO co CM o on on Q gt_x rH oj on a oj on a - rH oner
rmdash on sr i i
M z Z
gt gt gt
X-N CO laquomdashv CO CO bull igt gt bull
1 gt fc^gtgt bullbull ^ ^ ^
C 4-gt O t igt O J- 4J O H m o o o 3 bullH CO O rH in 3 bullH co vo o in 3 ~ 1 i-k -i ^trade fj rj ui ij o CO o n o rH =r co o n vo vo vo co o bullv O O O
O raquo On-3 rH O -bull- rH ON in _ IH in oj - rH bull rH VO OrH bull rH On ON pH d)u CO -UCO 4J OJ CO 4-gt gt
C mdashbull gt CM gt CM H-l O CO
v- ^^ N C 0
bull0 N CO
4-5 -0 _c^gt in in CO CO
C x~ c -^ t-oo in i 4J j_gt 41 4J bull 9 bull bull 4J bull
o j ON O O 3 (0 O4J O ON ON QJJ t~-^3- OJ 4-gt L
CO CM trade CO CM rH rH OJ co CM oj on Q ^ _ CO 3~Q-- n 45 Q mdash OJ OJ OJ C (0
1 11 3 nZ 2CO
gti gt gt CO CO CO ^-x m -s CO
rH rH ^ ro^^ bull gt bull ^ igt gt bullgt gtgt bull r O -Q 4Ji JJ O 5- JJ O pound- ^ O 4) oj o on (0 CO
3 bullH CJ O O in 3 bullH CO Cmdash VO on 3 pound-laquo H CO o n in inco co o n ma- r co g^ 5sect^ o
o rH on oj O bull- rH ONCO L O_ rH OJ VO M
rH bull rH =t rH bull - OJ T CO CO M CO 4-gt rH CO -U rH CO 4-) s
uits
CO 4-gt 4-5 T3 gt CM gt CM gt CM cc CO CO CO
3 3gt oa tlp^ CO O CM O gt 4J O 40 i 3 r+ k C pound JS
CO pound
^^ s -bullgt cmdash on poundZ VO CTI trx 4J 4J 4J
) bull bull bull Q Q Q Q4J 3shyc O-JJ CTgt OJ OJ Q-IJ inco on CO CO CO o co CM oj on co CM oj on co CM on
Q Q QON^ Q bullH Q^
rH rH 4J rH
O bullraquo L Z bull CO CO CO
i gtgt rH oj on gt tgtshyCM ^ cO^-s CO ~ CO
CO CO J X fc^_ bull^gt bullgtgt bull gt gtgt bull gt CO
j_ jJ O pound- Jj -P O Li deg =fObullH co on f- ^ 3bullH CO CO O in 3bullH CO
g^ -^2
poundsect HO
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mic
3 CO in in in in in in co o n co o n
o -^ r oj in O rHCO CO rH bullrH bull rH =T OrH bull rH OJ f-CO 4J bull- CO 4J rH O0) J-)
gt CM gt CM gt CM 4J
CO N_^ m^
bull OJ
t t poundshyCO CO CO CO rH J3 gt r-t oj on gt r-i oj on gt gt r n o j o n
lto co lto CO T bull ii-4 laquomdash bullmdashH
bullo CO L L 0)
CM CO cc
21
N
545-594
seepage observation
hole West Landfill
0NE I47-509
Area
Weir 45
i487-531
0 EC Al3-467
Legend bullmdash landfill limit -bull---excavation limit r-s stream
copy WNWNEECSESCSEN monitoring well locations
= = = unimproved road
Weir location and elevation
feet
Fig 9 Weir Locations and Wate r Level Ranges
22
JT NO
S shy S
O
bull ry m
oa
NO
(M raquo 1 03 or NO m
JT O O raquo
O NO 03 (j
PW tn in ^4 fraquo
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mdashraquo 3 M
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1 4 03 O
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i in
i ru
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i O
i ^
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^^ lt-l
r-laquo
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pound raquoraquo O)t o gtz
bull bull ltbull
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1 pound OJ
3 oi g bull
pound
1 pound laquolt bull
3 bull o a
pound
5 laquo15
f bull 3 Jl s
5bull 1 5
23
A field study to determine the infiltration capacity of a
section of tne landfill topcover was conaucted A modified version
of a double ring infiltrometer was used to study infiltration rates
(4) The cylinder diameters useo in this study were 8 inches and 18
inches A constant head of 6 in was maintained in the
infiltrometer and rates of infiltration were determined Tnese
results and an analysis of surface infiltration into the landfill
are included in tne analysis and discussion section
Specific conductance levels in the monitoring wells in the
streams bordering the landfill and at observation holes near the
landfill were measured (Fig 10) This is a good indication of the
mineralization of water (39) Specific conductances were measured
intermittently over the ten month period to develop a picture of the
extent and degree of contamination in the wells (Fig 11 Taole4j
and in the surface contamination monitoring locations (Fig 11
Table 5) A comparative standardization of the Beckman (short and
long probes) and YSI specific conductances is in Appendix C
A surface electrical sounding using the Schlumberger array was
conducted adjacent to Rose Hill Road at the R-l location (Fig 12)
in an attempt to delineate the vertical extent of the contamination
zone Well W was used as a centerpoint and a reference for
water-table depth pore water conductivity and depth to bedrock A
Schlumberger array electrical resistivity sounding was also
conducted in an uncontaminated area at tne R-2 location (Fig 12) to
provide a comparison background interpretation A seismic
refraction survey N-4 was conducted at the same location (Fig 8J to
24
N
excavat ion
Seepage West observat ion Landfill hole
Area
Stream 1 Seasonal observation 0 EC
hole
East Stream2
Legend sw Weir landfill limit j--1--^ excavation limit
copyWNWNEECSESC monitoring well locations
== unimproved road
feet
Fig 10 Surface Contamination Monitoring Locations
25
8000T
7000
O bull U) W6000
Legend
0 sc A NE O W
A SE O N W
a EC
1 O N D J F M M
Time months Flg11 Flucuatlon In Specific Conductance in Wells
26
Table 4 Specific Conductances in Wells (pmhoscm at 25degC)
West East Landfill Landfill
Date NW NE EG SE W SC N E S
81581 851 938 236 2356
102981 171 3268
11381 3268
111081 304 988 1100 258 3800
111481 426 2736 1216 186 4560
111781 304 3610 433 389 4560
121981 380 1406 129 103 380
1982 160 152
31582 274 760 1064 61 334 8000+ 182 53 84
52182 450 1500 1125 112 712 8000+ 175 255 150
52282 425 1320 1200 110 850 180 320 170
27
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28
excavation
West Landfill
Area
Legend bullmdash landfill limit -bullbull--bullexcavation limit r~~s stream
copy WNWNEECSESCSEN monitoring well locations
= == unimproved road
electrical resistivity sounding
feet Fig12 Electrical Resistivity Sounding Location
L
29
allow estimates of depth to water table and bedrocic to be made
Soundings were carried out to 500 foot electrode spacings to insure
that hredrock was penetrated and to facilitate interpretation These
results and a discussion of the soundings interpretation are
included in the analysis and discussion section Schlumoerger
resistivity soundings were made using a Soiltest R-bO unit
30
Model Development
The USGS Iterative Digital Model for Aauifer Evaluation was
usea to develop steady state flow models of the study area (43) A
flow chart of the computer model and a brief explanation of the
subroutines usea is presented in Appendix D The stream locations
elevations and aauiferlandfil1 geometry and hydraulic properties
were input to the model to compute head values at each 200 foot
grid spacing node (Fig 13) The input data which is for the
existing excavation and landfill conditon is listed in Appendix E
The head values that are computed at each grid space are in turn
loaded into the CalComp plotting routine (44) where a grid spacing
is setup with the computed head values at each node The contouring
program linearly interpolates between these head values and
generates a contour map The computer simulated ground-water
contour map for the excavation and landfill is presented in Fig
14
The streams in the model generally serve as controlling boundary
conditions When using computer simulated geohydrologic models of
an area choosing the boundary conditions for the model that are the
same as prevailing conditions in the field is a critical step in
model development Extending the models boundaries to areas in the
field that have a minimum influx of ground-water across them
simplifies the proolem of calculating fluxes from outside the model
area The eastern boundary is bordered by glacial till which has a
low hydraulic conductivity estimated to be 67 ftday(2) This
contrasts to the high hydraulic conductivity of glacial outwash that
makes up the model area of approximately 107 ftday(3036j
31 N
o 9
bullO O
32
33
The Saugatucket River serves as the controlling boundary on the
east A small drainage area directly to the east of it provides a
minimal influx
Beyond the moaels northern boundary the glacial outwash valley
extends to the base of a till covered h i l l on the western half ana
on the eastern side extends along the Saugatucket stream Due to
the relatively large drainage area that lies upgradient from the
northern boundary a recharge flux eduivalent to 10 inyr over the
drainage area on the till hill and outwash area north of the model
area was input as underflow (Fig Ib) Part of this was input at
each northern boundary node Till has a lower infiltration capacity
than outwash so more of the precipitation w i l l be transmitted as
overland runoff resulting in a lower ground-water baseflow The 10
inyr of recharge that results in a ground-water inflow from the
combined till and outwash region represents an estimate that is
smaller than the 14 inyr recharge for glacial outwash areas in
Rhode Island (25)
The glacial outwash valley extends beyond the western boundary
No significant ground-water recharge flux was estimated at this
boundary A relatively low ground-water gradient exists to the west
of this which does not provide a significant flux across this
boundary Tne southern boundary is basically the outflow region for
the area and therefore would not reauire any ground-water flux into
the moael area across this boundary This boundary was set south of
the point that the streams in the model merge together Therefore
the streams which lie to the north of it are the controlling
34
scale 124000
Fig 15 Northern Drainage Area
35
boundary conditions The flux out of the downgradient outflow
region approximately eauals the influx from precipitation recharge
and boundary influxes
When tne stream configuration in the moael area are reviewed it
can be seen that they comprise a large portion of the boundary
area The screams can act as sources or sinks for water in the
model thus providing to and removing water from the aquifer The
leakance option was used in the model which provides for a confining
bed and aouifer area beneath the stream to be input
The leakance is defined as the hydraulic conductance of the
streambed divided by the streambed thickness which in this case is
taken as 1 foot The leakance value at each streambed node
restricts the flow between the aduifer and the stream The
streambed hydraulic conductivity is typically 01 the value of tne
hydraulic conductivity of the aduifer (717) The value 107
ftday was used for a streambed conductivity based on a value of
107 ftday for the aquifer The aduifer and stream hydraulic
inputoutput exchange at eacn node is calculated by initially
finding the difference between the initial field stream head
elevations and the computed head elevation values at the
corresponding nodes This head value is then multiplied by the
(Leakance value at each node) x (stream area of each node)
Therefore if the aduifer head was lower than the stream head the
stream would act as a source of water for the aquifer and vice
versa
36
Tne leaxance input at each stream node is the ratio of the
actual field streambed area in each node to the area of each node
which is 200 ft x 200 ft = 4 x 104 ft2 The west
excavations stream width is approximately 3 ft central 4 ft and
east 5 ft Therefore if tne west stream traverses the node
directly without meandering it presents a leakance of 3 ft x 200
ft4 x 104 ft = 015 Leakance and streamhead values were
input at each node to set up the stream flow parameters in the
models
A recharge value of 14 inyr over the entire area was input at
each node This represents a value of precipitation that is
transmuted into tne ground-water rather than being directly
evaporated evapotranspired through plants or overland flow
runoff The precipitation recharge flow from the stream into the
aauifer and boundary fluxes provide the model witn input flow
parameters
From analyzing the available information it was determined that
the study area lies within a glacial outwash area with a relatively
shallow bedrock The seismic survey around the landfill generally
indicates a depth to bedrock below the land surface of approximately
29-43 ft with corresponding saturated thicknesses of 19-33 ft as
seen in Table 2 This agrees with borings from tne USGS groundwater
map in the stuuy area (18j The seismic survey was run at a low
water table condition which was several feet below the high water
table level (Fig 9)
37
High water-table saturated thicknesses were used to develop
model parameters For the purpose of this model study the saturated
thickness was set at 30 ft except in the vicinity of well W where
there is a bedrock high (Fig 8) At this location a high water
table saturateo tnicxness of 8 ft was estimated In tne vicinity
the seismic survey was conducted the bedrock elevation at this
location is the highest and the saturated thickness the least Tnis
can be seen by an east-west cross section of tne landfill (Fig 16
The boring log for well W indicates a sand trace gravel outwash
material (Appendix B) Boring logs at the eastern landfill area N
and E indicate similar material On this basis the hydraulic
conductivity was estimated at 107 ftday (3036) Witn the
exception of the landfill and the bedrock hign areas the
transmissivity values were set at 107 ftday x 30 ft = 3210
fto day From the literature the hydraulic conductivity of the
landfill material was estimated at I ftday (19) The
transmissivity of the landfill material in tne nortnern section was
estimatea at 1 ftday x 30 ft = 30 ft^day or approximately two
orders of magnitude lower than the outwash In tne landfills
southern section the original excavation was not as deep as in the
northern parts The landfill material was estimated to makeup only
one half tne saturated depth the remainder being the original
glacial outwash material (Fig 17) Therefore the transmissivity
at the southern end was estimated at 15 ft x 107 ftday + lb ft x
1 ftday = 1620 ft^day These values were graded into the 30
ft^day values at the landfills northern halfway point These
38
were input as transmissivity values to the model at their respective
locations This model did not use the water taole option so
water-table fluctuations did not affect the transmissivities
39
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Model Calibration
A simulation was run using the initial estimates of stream
parameters aquifer and landfill hydraulic conductivities
transmissivities boundary and recharge conditions to approximate
water taole conditions in tne fiela Initially the existing
condition of the excavation area to tne west of Rose Hill Road and
the landfill to tne east were modeled in order to calibrate the
model to current field conditions as shown on Fig 4 The simulated
well values (Fig 14) fall within tne range of field values (Fig
9) The resulting contours also provide an approximate matcn This
can be seen by comparing Fig 4 with Fig 14 An additional check
was to match the flow loss and gain in the streams between tne weirs
in the central stream which w i l l be discussed later The
simulated flow value from the excavation drainage stream is the same
as that measured at the SW weir location Having calibrated the
model by approximately matching well water levels nead contours
and scream flow values different field conditions and possible
remedial measures can be simulated
When the model grid was laid out over the study area as viewed on
Fig 13 the stream configuration rarely traversed the grid nodes near
their central axis When the stream locations were input to the
computer the information was documented as crossing the central axis
of the grid nodes The result of this is a slight aberration when
the actual stream configuration is laid over the computer graphics
head contour output The streams dont always cross the groundshy
water contour at the logical location Rather than modifying the
actual stream configuration to adjust then to the computer output
their actual locations are presented
42
Simulations
i The primary focus of the computer modeling is to analyze flow
patterns under changing conaitions in the near vicinity of tne raquo
landfill The study areas overall flow patterns as they exist
today are first presented in order to realize the lateral east-west
head contour lines between the stream that directly borders the
landfill on the east side and the SaugatucKet stream (Fig 14)
This indicates a general southerly flow direction in that area As
different conditions are modeled these contours generally maintain
their east-west orientation In order to facilitate interpretation
of flow patterns in the near vicinity of the landfill flow patterns
to the west of the stream that borders the east side of the landfill
r are presented in the subseauent models
L- Natural Conditions
The results of modeling the original natural conditions are
shown in Fig 18 The excavation and stream to tne west of Rose
Hill Road and tne landfill did not exist in this simulation The
southwestern boundary consists of a drainage stream that was
delineated using an aerial photograph and stream elevations were set
using the topographical map The USGS ground-water map (18) was
used to estimate head values between the west excavation and north
streams These were input to the model as constant heads on the
models western boundary The resulting simulation generally matches
the southeasterly flow direction that is indicated on the
ground-water map (Fig 5)
A3
Legend
x-^- stream 400 = = = unimproved road
I f ee t
Fig 18 Natural Conditions
44
Excavation Without Landfill
The condition of the excavation to the west of Rose Hill Road
with its resultant drainage stream without the landfill was modeled
next (Fig 19) The extent of the excavation ana the location of
the new drainage stream were delineated using the aerial
photograph The west stream elevations were sited in the field and
used in the model The concept of a confining streamoed layer was
excluded in tne excavation drainage stream under the concept tnat no
significant organic layer had been built up within the 25 year
period that the excavation had been initiated Head values between
the west and north stream boundaries were interpolated and input as
constant head values on the northwestern boundary The west
excavation drainage stream creates a condition that alters the
natural ground-water flow patterns by creating a more southerly flow
condition the drainage stream providing a more immediate surface
outflow in that area
Landfill Without Excavation
The hypothetical case of a landfill without the excavation was
modeled next (Fig 20) The low hydraulic conductivity zone of the
landfill changes the natural flow conditions and creates noticeable
mounding This is evidenced by the decreased spacing of the head
contour lines and deviation from the lateral contour lines of the
natural conditions and higher head values (Fig 21)
45
Legend
excava t i on s t ream
400 unimproved road
f e e t
Fig19 Excavat ion without Landfill
46
Legend
landfill limit
bull - s t ream 400 copy WNWNEECSESC
monitoring well locations f ee t bullbull-bull=bull unimproved road
Fig 20 Landfill without Excavation
1
oin CM
bull
m u
0)rf
oO
bullo 9
bullo 9
o rf o o CO 1
lt0inO O
T ^ogt
c o
47
o9 aI 0)
ot_3 O laquolaquo coO bull3 OJ oX
bulla caj
CM
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48
Landfill ana Excavation
The condition of tne existing landfill and the excavation with
the dam is the next condition modeled (Fig 22) The ground-water
elevations used to calibrate tne model correspond to an actual high
water table condition Between the NVJ and pound weir a streamflow loss
of approximately 102 gpm occurs aoout 60 percent of this flow is
lost at the dam site which maintains a head of b-6 feet over an area
of approximately 1800 feet^ This approximates a field value of
1144 gpm influent to the aduifer between the NW and E weir on ]2
December 1981 (Table 3) From the E weir to the SE weir a net
increase in flow occurred of 74 gpm which corresponds to field
increase of b62 gpm
The surface runoff from tne landfill flows primarily toward tne
eastern side of the landfill Increases in water-table elevations
on the eastern side after heavy rains such as the 11 November 1981
storm indicates that this runoff increases outflow gradients to the
stream and therefore increases streamflow Surface runoff input is
not modeled which explains in part why field stream inflow values
are slightly higher than model predictions especially for periods
after a storm has occurred The flow from the SW weir located at
the southern end of the excavation represents drainage outflows from
that area The net flow calculated in the model was 140 gpm
which approximates field conditions of 1642 gpm on
December 9 1981
49
d f l f reg N E
shy
Legend
landfill limit -bullgt-bullgt- excavation ^-N_X- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road
-40mdash approximate groundwater contour
400
feet
Fig 22 Landfill and Excavation with Dam
50
The modeled flow patterns suggest how the various contamination
zones around the landfill have developed to their present state
They indicate a flow to both the southeast and southwest on their
respective sides of the groundwater divide Evidence of a
southwesterly contaminant flow is presented when the continued high
specific conductance contaminant level in tne observation seepage
hole is realized (Table 5 ) In addition the specific conductance
increase in the west excavation stream is evidence of an influent
contamination flow
Contamination flow to the eastern and southeastern side of the
landfill is obvious High specific conductance levels in the wells
on the eastern side (Table 4 ) a specific conductance increase
between the E and SE weirs (Table 5 ) and contamination in the NE
domestic supply well (Fig 3) present conclusive evidence of
contamination to the eastern side of the landfill
An anamalous condition that exists is a domestic supply well
located approximately 300 feet due south of the landfill remains
uncontaminated (Fig 3) Flow patterns indicate that contamination
would be transported from the landfill south to this area
(Fig 14) One explanation is that a pocket of clay at the southern
end of the landfill area was discovered in the original excavation
for the landfill (lt6) This evidently prevents leachate from
reaching this wells radius of influence
51
Summer Conaitlon
As described earlier during dry months of the year the stream
that normally borders the northern and eastern side of the lanafill
may dry up as far as a point southeast of the E well Tnis
condition existed from the 15 August 1981 to the 27 October 1981
period when streamflow commenced in the northern part of the stream
yet did not overflow the north dam until 17 November 1981 This
created the present day continuous flow condition throughout the
stream These summer conditions were modeled by removing the stream
above the aforementioned location while other conditions remained
the same (Fig 23) Summer condition well water levels listed in the
model generally match field low water table conditions (Fig 9)
Because there is no stream upgradient from the landfill to provide a
stream head and infiltration through the streambed groundwater
runoff from the area north of the lanafill is the controlling flow
input In these moaels an average recharge of 14 inyr was used
which represents a yearly average The summer recnarge conditions
are prooably lower given the effects of decreased rainfall and
increased evapotranspiration during the summer months A domestic
supply well whicn exists northeast of the landfill (Fig 3) nas a
greater potential to be contaminated from the lanafill at tnis time
than when the stream is flowing Flow patterns from the landfill
are such that during an upper stream no-flow condition groundwater
flow patterns are more in an easterly direction than in a
southeasterly direction The stream would act as a source of
infiltrated water upgradient from tne landfill and provide a
52
I ^N gt i I i j i -r- -bull- bullr -T- t- -r- i- TJ JV
bullbullT laquo ^ O - laquo bdquo xi cshy
H r^~ I -~- --^ X- = mdash x^ N
^--^ A bull O^NW -v - gt-bull Ni i I _____mdash - bull laquo l - mdashmdash 1 deg I ^ltv I C
I reg NE A
Js bull vbull A ~ - v T gt- ^ ix - N
-5Z- | N TfS lV I -bull bull iA i gt gt I ^ bullr-Ky L bull 1 _- copy]wgt-- - bull- mdash - - shy
= r Y ~mdash ltmdashA A
^^-lt A _ - - - - bull Hmdash - reg EC x ^-mdash mdash I ---mdash_mdash -t-V-^N - y
I- -bull - r x i X
V ^ 7 I -v (^~~^^r ^^^
sc Emdash-bull vV JI - - - ~ r )N y- -
X - bull r bulllt
^bull^ y y Jlaquo^ - -lt shy
T s^ lt^ ^ +^-b (
X
Legend
landfill limit j-j-bullraquobull excavat ion gt^ -x- s t ream
reg WNWNEECSESC monitoring well locat ions
= == unimproved road fee t
Fig 23 Summer Condition
400
53
constant head across tne northern section of the landfill This
would tend to orient the flow in a more southerly aowngradient
direction In addition the stream which flows adjacent to the
northeastern well could provide a source of infiltrated clean water
to it which would minimize the possible contamination from landfill
leachate
Without Dam
During tne spring scream flow condition the dam failure which
occurred between the 15 March 1982 ana 9 April 1982 monitoring
periods decreased flow to the aauifer and landfill This eliminated
the 5-6 foot head difference over a 19000 ft^ area which had
created a larger area and elevation head for infiltration to occur
The condition without the dam was modeled by reducing the area
encompassed by the dam to a 4 foot wide stream channel thus
reducing the leakance value at that node (Fig 24) The flow change
from the stream to the aduifer between the NW weir and E weir
reduced the model flow loss to 50 gpm Tnis corresponds to the 9
April 1982 monitoring period which indicates a 30 gpm loss
As compared to the previous flow loss in the upper stream
sections to the aauifer the 21 April 1982 and 22 May 1982
measurements between the NW and E weirs indicate a flow gain The
streamflow conditions have changed from an influent
stream-to-aauifer condition to an effluent aduifer-to-stream
condition that increases flow downstream
54
Legend
landfill limit j--i--i- excava t ion x-gtmdash^- stream 400
copy WNWNEECSESC monitoring well locations
= == unimproved road f e e t
Fig 24 Landfill and Excavation without Dam
55
Analysis and Discussion
In order to fully understand flow patterns and Quantify leachate
outflows at the landfill it is necessary to arrive at an estimate
of flow inputs from precipitation ana upgradient sources In the
following analysis it will be demonstrated that the rainfall input
to the landfill is the factor which controls leachate generation A
calculation using the H inyr recharge over the area of the
landfill was made to estimate the leachate outflow due to rainfall
infiltration An estimated 134 gpm is generated from the entire
landfill area Simulation of the existing conditions (Fig 24)
indicates a groundwater divide in the landfill is located
approximately at the western third Therefore approximately 23 of
the generated leachate flows to the eastern side of the landfill or
9 gpm The effect of the flow input from the upgradient stream is
evident when tne summer condition witnout the stream is viewed
(Fig 23) Without the stream to infiltrate the landfill and the
recharge and northern boundary condition as the flow inputs the
head at the northern end of the landfill drops about 5 feet from its
previous value A flow pattern from the north central part of the
landfill to the eastern side indicates a 12 feet head difference
with recharge - but with the upgradient stream a 16 foot head
difference occurs Considering the transmissivity change the
stream would increase the leacnate outflow from the landfill
approximately 43 under a low water table stream influent condition
to the aauifer This would increase leachate outflow to the east
side to approximately 129 gpm This value approximates the
56
outflow at the SE weir location during the summer monitoring period
when the upper stream was not flowing (Table 3) The outflow from
the western third of the landfill whicn lies to the west of the
ground-water divide would be approximately 63 gpm
Realizing the importance of infiltration to tne landfill as a
major influence on the generation of leachate an analysis of this
w i ll be discussed An estimate of infiltration was made using the
precipitation recora for October ana November (Appendix A) During
this time period a minimum of direct evaporation ana
evapotranspiration occured and the grouna is not yet frozen The
top cover over the lanafill is generally 05 ft to 2 ft of local
sandy soil and subsoil availability determined what was used The
top of the landfill is at an elevation of 92 ft as compared to the
ground surface at well W which is at an elevation of 76 ft
(Fig 25) This compares to the well W water level which is at an
elevation of approximately 52 ft This creates a long path for
infiltration through the unsaturated zone The topcover generally
slopes eastwara at a grade of 2-5 The west side maintains a
relatively steep slope of 10-15 ft drop within 50 ft ana the north
and eastern slopes have a more gentle slope of approximately 10 ft
within 100 ft distance An unlined surface arainage swale channels
surface runoff from the northern section of the landfill past the
NE well to the eastern side ana low area in the vicinity of the E
well This has a drainage swale to an area near the stream but
doesnt directly connect to tne stream A poorly graaed drainage
swale exists on the landfills left side The landfill material has
57
excavation
seepage observation ^
hole
Legend bullmdash landfill limit -^--excavation limit r^s- stream
copy WNWNEECSeSCSEN monitoring well locations
--- unimproved road O location of amp Inf i l t rometers O
feet
Fig 25 Infi ltrometer Locat ion and Drainage Feature
58
been placed in 10-12 ft cells and covered with 1 ft of soil at the
end of each day The material has settled differentially creating
areas for depression storage
An estimate of the percentage of precipitation that infiltrates
the landfill was made from precipitation records recorded well
elevations and an estimated specific yield for the landfill
material The volume of water that infiltrated should eaual tne
specific yield multiplied by the well water level rise Several
recharge periods were studied using this relationship Once the
percentage of precipitation that has infiltrated is determined the
percentage that is translated into runoff is simply the remaining
percentage if evaporation is neglected
From the literature for a slightly inclined slope of 2-5
typical runoff coefficients range from 10-20 in either sandy or
heavy soil (16) The landfill cover is generally sloping to the
east which creates a long path (approximately 400 ft) before the
runoff reaches the steeper slope on the eastern side of the landfill
of 15-20 The long drainage distance creates a greater time for
rainfall to infiltrate Another consideration is the actual
capacity of the soil to conauct water into the soil which was tested
in the field using double ring infiltrometers An average initial
percolation of 8 mmhr the first hour and a subseauent rate of b
mmhr occurred (Fig 26) The 8 mmhr rate compares well with
other sandy soil infiltration rates (14) Therefore if the
intensity of the rainfall exceeded a 5 mmhr rate for several hours
59
CO + 09 o
E o
CO
o Z pound C
O
C9
o DC
CO
CD CM
ogt CO N- to -4 CO CM
jq tuu i U O | raquo B J J | | J U |
60
on a poorly drained surface the additional rainfall would be
translated into runoff because the soils infiltration capacity had
been exceeded
The initial 8 mmhr infiltration rate was due to the pore spaces
in the sandy soil being filled and the subsequent 5 mmhr rate was
percolation into the low permeability landfill material The tests
were conducted in November assuming a minimal evapotranspiration
and the field capacity of the sandy soil had been maintainea
The W well was used as representative of the water elevation
changes in the landfill because it is directly adjacent to the
landfill 900 ft distant from the upgradient stream This minimizes
the effect of infiltration from the stream and maintains a high
contaminant level During periods of high runoff conditions excess
surface water ponded in a poorly graded drainage swale on the west
side and directly adjacent to the landfill This influenced the W
well at a time the contamination level dropped (Fig 11) Before
this occurence in mid-December the rise of the W well closely
matches that of the SC well and a background well SK6 which is
located outside the study area (Fig 7) Therefore it was analyzed
as a valia indication of the water level rise during the mid-October
to mid-December period The monitoring of the SC well was
intermittent due to inaccessaoility because of 10 ft extensions
being placed on the well as the refuse was being filled in arouna it
61
A high rainfall period from 14 November 1981 to 1 December 1981
was chosen for the initial study period The effects of
evapotranspiration were neglected due to the cool temperatures
experienced at this time Therefore it was assumed that the field
capacity haa been reachea and tnat any additional input to tne
unsaturated zone would result in direct percolation to tne saturated
zone During the time period 14 November 1981 to 22 November 1981
029 ft of rainfall fell and the well W rose from 488 ft to 493
ft - a 05 ft increase During the next 8 day period there was no
precipitation yet the W well continued to rise to 4972 - a 042 ft
increase The slow percolation of water through the landfill
material would account for the latent rise in the well water level
From previous reports a specific yield for refuse was estimated to
be 028 (1920) This value is dependent on the original compaction
of tne material age and resulting consolidation
During the 14 November 1981 to 1 December 1981 period 029 ft
of rain fell and the well increased 092 ft The following
relationship is used to evaluate the infiltration value and runoff
I = (Sy) h
Sy = specific yield
h = well rise
I = volume infiltrated
I = (028) (092 ft) = 0261 ft
62
The difference between the precipitation and the infiltration is
the runoff (assuming no evapotranspiration) Therefore 029 - 026 =
003 and furthermore 003029 - 13 runoff This corresponds in
the literature to a typical runoff coefficient for an inclined
surface of 2-5
Analyzing a longer precipitation period from 18 October 1981 to
1 December 1981 a net precipitation of 043 ft (accounts for
evaporation) occurred less 10 for runoff or 039 ft infiltrated
This results in a 139 ft elevation increase The well water level
actually increased 132 ft shy only a 5 deviation from the
calculated
From tnis investigation it is seen that a large proportion of
the precipitation has the potential to be transmitted into the
landfills saturated zone Exceptions are wnen heavy precipitation
periods exceed the soil percolation capacity frozen ground prevents
infiltration and direct evaporation and evapotranspiration recycles
the ponded surface water and infiltrated soil moisture back to the
atmosphere In retrospect water temperatures within the monitoring
wells could have been measured to indicate thermal effects from the
landfill on ground-water temperature Ground-water temperatures
were assumed to be 50deg F (9)
63
Specific conductance measurements serve as an indication of
contamination levels These measurements are used to trace leachate
movement which represents ground-water flow patterns Factors which
must be considered when monitoring pollutants are the attenuation of
the leachate contaminants which occurs both in the zone of aeration
and the saturated zone The former is a more complete process
Dilution dispersion and cation exchange are the primary factors
involved in decreasing leachate concentration in the saturated
zone The glacial outwash materials of southern Rhode Island do not
have a cation exchange capacity or a high buffering capacity so
attenuation is simply by dilution and dispersion (22)
The NW well consistently exhibits relatively low specific
conductance levels even though it is in landfill material It is
situated in a drainage swale and ground water elevations range from
543 to 5944 This is several feet below the upgradient stream
elevation of 64 feet which is less than 400 feet away The bottom
of the wellpoint is at an elevation of 5312 feet well into the
landfill material Infiltration from the stream to the landfill has
occurred at this location
The W well is situated on a bedrock high adjacent to the
landfill approximately 900 feet from the upgradient stream and its
water level is higher in elevation than the excavated pit (West
Observation Hole) which is 300 feet directly west The W well
maintains a contaminated level A poorly graded drainage swale to
the west of the landfill provides areas for extensive ponding and
infiltration to occur which explains the drop in conductance after
a high runoff period
64
The SC well is located in landfill material and has a
conductance of over 8000 umhos This indicates that leachate is
undiluted The oottom of the wellpoint is at an elevation of 389
feet which is situated in the landfill material
High specific conductance measurements in the west observation
hole and well W and their relative elevations indicate a
west-southwesterly flow direction from the landfill Infiltration
recharge and leakance from the stream into the landfill provides the
necessary elevation to cause outflow in this direction
Contamination from the landfill to the surrounding streams is
evident (Table 4) During the period 15 August 1981 to 27 Octooer
1981 there was no flow in the stream that Borders the northern and
eastern side of the landfill until a point just south of the E well
was reached High specific conductance levels in the EC and NE
wells were recorded (1000 jjmnos) At a point directly east of well
EC a pool of water existed that was relatively uncontaminated which
is designated as the East Stream] location (Fig 10) At a point
just south of that (East Stream^ polluted water in the streambed
was flowing at a low rate This was measured at the SE weir
location and which had a high conductance also Flowrates varied
between 6 and 23 gpm and specific conductances were over 350
pmhos This low water table condition flowrate is the baseflow from
the eastern side of the landfill and indicates a southeasterly flow
direction from it
Streamflow commenced in tne northern part of the stream 21
October 1931 and the north dam oegan to f i l l Stream specific
65
conductances were low indicating a clean water source Tnis
continued until 17 November 1981 when the dam overflowed ana flow
throughout the east stream began A weir was placed at the Rose
Hill Road NW location and was compared to flowrates at the SE
location Flowrates decreased and specific conductances increased
between these two locations
To further investigate the condition of a lower flowrate
downstream than upstream an intermediate weir was placed at the E
weir location (Fig 9) This snowed tnat the stream from the M
weir to the E weir was losing water to the aauifer (influent
condition) and gaining water at the SE weir (effluent condition)
The condition of a net loss of water between the NW and SE weirs
remained until 19 December 1981 when a snowmelt rain condition
caused increased surface runoff and a net increase in flow at the SE
location Upon analyzing the March and April 1982 streamflow
conditions the expected case of a net ground-water pickup from the
E to SE weir continued The explanation for tne initial net loss of
ground-water is the fact that the leakance from the upstream section
was being discharged into aauifer storage to raise the ground-water
table to an eduilibrium level Upon reaching a high recharge
equilibrium steady state condition any additional input will
eventually be transmitted as baseflow out of the landfill and a
downstream net pickup will occur A hign water table condition
prevailed during the January through May period maintaining this
condition In April the north dam broke through reducing the head
in that area by 4-6 feet The 9 April 1982 monitoring revealed that
66
an influent condition remained between the NW and E weirs but at a
reduced rate The 21 April lower stream flow condition shows a
small pickup of water between the NW and E weirs indicating the nigh
water table and low stream flow conaitions combined with the absence
of the dam had changed the conditions to an effluent condition
This was evident in the May monitoring period
Evidence of contamination on both the western and eastern sides
of the landfill supports the existence of a ground-water divide in
the landfill The west stream which drains the excavated area to
the west of Rose Hill Road shows contamination pickup between its
northern section and the SW weir The W well and ooservation hole
indicate high contamination levels which reinforces the concept of a
contaminant outflow to tne west excavation stream
As shown previously flow towara the eastern side of the
landfill is evident from the nign specific conductances and specific
conductances increases in the stream This is especially evident
during low flow conditions when the stream starts at a point to the
east of the landfill and flows with high specific conductance levels
From the literature a relationship between specific conductance
and dissolved solids exists the dissolved solids (mg1) are
approximately equal to the specific conductance times a factor
ranging between 55 and 09 (39) in this case it is taken as
065 (41) The dissolved solids increase coupled with the stream
flow increases provides a basis of calculating the dissolved solids
outflow to tne stream This calculation method was used in a
previous study (26)
67
The relationship
=Cinout Coutflow Qoutflow - Cupstream Qupstream Qinput
where the numerator is the streamflow pickup and the C- and
Q-jnput is the concentration and flow input from the ground-water
This can be used to estimate dilution level outflows from the
landfill Initially this is used for the ambient ground-water
pickup between the E weir and the SE weir This entire flow doesnt
come from tne lanafill but much of it is conaucted in the high
transmissivity area between the lanafill and stream from upstream
leaxage ana surficial recharge Tnis is evident when this section
of the flow pattern is analyzed on Fig 22 Therefore the landfill
outflow is mixed with tne ambient groundwater flow which dilutes the
landfill leachate before it enters the stream To illustrate-this
concept a calculation using the 9 December 1981 monitoring is used
At this time a flow of 672 gpm occurred at the SE weir with a
specific conductance increase of 7 ymhos between the E and SE
weirs The dissolved solids increase would be approximately 795
Today in tne stream
Where
Co = 90 jumho at SE weir
Qo = 672 gpm at SE weir
Cus = 83 jumho at E weir
Qus = 606 gpm at E weir
Qinput = 66 gpm gain
Cinput = 154 jumho
68
The 154 jumho value represents the contaminant level in the
ground-water adjacent to the landfill
This relationship is applied to approximate the concentration
level dilution in the ambient ground-water between the landfill and
stream The aforementioned relationsnip is in turn applied to the
landfill outflow into the ambient ground-water flow adjacent to the
landfill The ground-water receives landfill leachate dilutes it
and then transmits it to the stream The previously calculated
value of 129 gpm was used as the outflow from the landfill
Co 154 jumho flows into stream
Qo = 67 gpm flow into stream
Cus = 83 jumho background level
Qus = 67 gpm - 129 gpm = 541 gpm
Qinput = 129 gpm from landfill
Cinput = 451 jumhos
Approximately tne same contaminant levels from the landfill (tbl
umho) are arrived at as existed in the summer streamflow conditions
when the upgradient ground-water flow adjacent to the landfill was
at a minimum
In addition to using specific conductance to define
contamination zones electrical resistivity can be used to indicate
contaminated areas The measured earth resistivity is inversely
proportional to the conductivity of ground-water Water containing
contaminants with high ionic concentrations are more electrically
conductive and will have lower resistivity values than surrounding
natural ground water Therefore resistivity methods can be used to
69
delineate plumes of contaminated ground-water that have hign
specific conductances This has been demonstrated by several
investigations (11122328374045)
In this study a Schlumberger vertical electrical sounding R-l
was made in an area of known contamination at the W well (Fig 12)
Given the geologic constraints provided by the well boring log a 4
layer computer model was used to match field survey values A
Schlumberger sounding R-2 in an uncontaminated area north of the
landfill in the same geologic setting was used to provide a
comparison background sounding (Fig 12) A seismic survey N-4 was
made to obtain water table depth and depth to bedrock as input
parameters to a four layer resistivity model (Fig 8) Tne results
of the electrical soundings have been tabulated in Table 6 and
plotted in Fig 27 and 28 respectively
The ascending portion of the field Schlumberger curves were
initially matched using a two-layer ascending type master curve to
provide an approximate depth and apparent resistivity of the
overburdened topsoil layer (8) Tne second unsaturated layers
apparent resistivity was determined by using the graphical
interpretation of total transverse resistance The total transverse
resistance is approximately eoual to the peak value of the curve
times the corresponding Ab2 distance it occurred at This in turn
is eaual to the sum of the first two layers apparent resistivity
times their corresponding layer depths
70
bullH
OJ bull bullH 4J CO CM
c ce G bullrH
j-gt ca c c a 3 ltu O L
co CO 0
bullo Q bull laquos c n 3 -U OrH f~ 3 bO ltn y CO O cc CO ^mdashN
QQ bull
bO bOJJ C C Ci_i
O l T i O O O O O O O O O O O O O O O O bullH bullH mdash^ bullo 0 C c3 f| 3 O raquo O CO CQ
CO
rH
CO O
L 4J
^ltU
i- 1 ^n ^b O 4-) bull2 CM bullH C OJ 1 -U bullH CO C L O a ^-^ 0) a
rH c a L CD ltu (1) 3 tlt bO cO I
3 a 0) a Q 4J laquoa e CO 3 (H bO c C O bullH
CO TJ C 3 bull
bull O bO -i-3
0 CO C O3- O G O O O O O O O O O O O O O O O O O O ft rt1 -raquo - t l S^ ft tfigt f I mdash^ K_ l_ raquo mdash I gt fgt I l 1
(1) 0 rH CO CJ JD o^^ CO CO CQH lts
71
Legend
A actual field measurement
-e- interpretat ion
10000 bull
6000 bull 5000
4000-
3000shy
pound2000| ltD
_ r 1000
09
5 600 pound 500 - 400
I 300 a a lt 200
100 10
Fig 27
20 30 4050 100
Distance AB2
Schlumberger Sounding
200
feet
R-1
400 600
72
loooot
6000 5000 4000
3000+
laquo2000 e
r 1000
raquo 600 pound 600 ~ 400
$ 300 a a lt 200
100
Legend
A actual field measurement
-Qmdashinterpretation
10 20 30 40 50 100 200 400 600 Distance AB2 feet
Fig 28 Schlumberger Sounding R-2
73
Formula T = f
Background Sounding (9000)(15) = (3110j (1 7) + gt2(8)
= 16214 n- ft
W Wel l Sounding (b200)(60) = (500) (2) + pound2(28)
= 13250 SL- ft
To determine a resistivityp3 value for the third layer a
graphical interpretation for the longitudinal conductance S was
used(48) This is eaual to the sum of each individual layers depth
divided by their apparent resistivity
Formula S = -r1 +~r-raquobull-ra
Background Sounding 0017 = yyg + ~^
= IbOU - ft
W Well Sounding 0285 raquo -ggg 7^3 J~
= 179 v-ft
These values were input to a program which calculates a
schlumberger sounding curve (47) The theoretical sounding curves
approximately match the field curve as viewed on fig 27 and fig
28 To provide a check on the apparent resistivity of the saturated
layer at the W well the following relationship was applied 1OOOO
= spec-jfic conductance (umhos)
74
At the W well the specific conductance was measured to be 3 00
jmhos at approximately 10degC
Assuming a formation factor of 45 for the glacial outwash (23)
material Archies law is applied to estimate an apparent resistivity
of the third layer (7)
fgt FF x p
A= 45 x 103-n-ft
A= 4G3 JL-ft
This is a reasonable approximation to tne 3i= 179^-ft calculated
analytically from the sounding curve interpretation
75
Remedial Measures
With the analysis of f low patterns and contamination zones
recommendations to minimize the environmental impact of the leachate
can be reviewed The basic technique is to minimize all sources of
water reaching the refuse so that leacnate production is minimized
The oiversion of precipitation by a relatively impermeable cover and
proper channeling of runoff would minimize percolation into landfill
material Caps and seals can be constructed of clays fly ash
soils soil-cement lime stabilized soil memorane liners
bituminous concrete and asphalttar materials (15) Proper
contouring and grading will help minimize infiltration If a soil
cover is used a vegetative cover can be planted which will utilize
some of the infiltrating flow through evapotranspiration losses
during the growing season By minimizing the length of slopes and
providing proper drainage channels tne surface runoff can be
conveyed to a downgradient area outside the recharge zone
Therefore this surface water will not increase leachate production
from the landfill Also by increasing the slope of the cover over
the landfill itself a higher percentage of runoff and lower
infiltration will occur
To minimize upgradient ground-water influx to the landfill an
impermeable subsurface barrier or intercepting trench could be
used Barriers can be made of bentonite slurry-trench cutoff walls
grout curtains or sheet piling cutoff wal ls extending to the bedrocic
or an impervious layer to effectively prevent water passage or
create a head loss that wil l lower the water table In addition an
76
intercepting trench which has a perforated drain at tne lowest part
of the water seepage zone could be used to intercept and divert the
entire flow
These possibilities have been evaluated with the help of the
model to determine workable solutions for this landfill The
primary concern is to eliminate leachate flows to domestic wells
Initially a simulation was run that eliminated recharge over tne
landfill area (Fig 29) This had a considerable effect on the
ground-water flow patterns of the landfill area The mounding that
had previously occurred under normal recharge conditions was
eliminated and a general drop in the water taole within the landfill
of 2-3 ft occurred The effect of eliminating recnarge over the
landfill when the upper stream is running would cause greater
infiltration from the stream as evidenced by only a 2 ft head loss
in the landfills flow conditions This is evident when comparing
Fig 29 with Fig 24 Tnis indicates that this measure would only
marginally reduce the resultant leachate flow from the landfill
material that lies below the water table In another situation
where there is not such a strong potential for upgradient flow this
measure has proven quite effective (6) In this case the landfill
cover consisted of four layers an intermediate sand and gravel
cover immediately above tne regraded waste materials a 4 inch sana
bed designed to protect the overlying membrane a ilO mil flexible
PVC membrane and an 18 inch final cover of sand and gravel
77
Legend
landfill limit -raquo- -^ -raquobull excava t ion x-^x- s t ream
400 copy WNWNEECSESC monitoring well locations
= -= unimproved road fee t
Fig 29 No Recharge over Landfill
78
Controls such as 10-30 mil polyvinyl chloride covers favor the
development of an anaerobic environment which increases waste
decomposition time and would necessitate installation of gas vents
at several locations on the landfill cover Tne integrity of tne
synthetic cap may be further threatened by subsidence which create
differential stresses on liners Settlement would create areas for
ponding and depression storage and eventually necessitate regrading
the landfill surface The landfills south-central area has oeen
filled within the last year and will prooably need to be regraded
due to settlement within the next few years
Another possibility for a liner would be a soil-bentonite
cover A layered cover consisting of natural materials with low
permeabilities such as bentonite clay followed by a layer of highly
permeable material such as sand and finally a layer of topsoil can
be used Due to potential drying out and cracking of the clay liner
a synthetic liner is the preferred method
The most immediate technique is to grade contour and vegetate
the landfill cover which has been done at this site Althougn an
impermeable cover would probaoly reduce the amount of leachate
produced it would not eliminate the upgradient flow and provide
guaranteed protection of wells in the vicinity of the landfills
northwestern section
A slurry trench along the northwestern perimeter of the landfill
would effectively cutoff upgradient infiltration and divert recharge
infiltration in a southeasterly direction thus removing possible
leachate outflows from the radius of influence of the neighooring
79
wells This has been simulated using the computer moael ana flow
patterns as shown in Fig 30 Contour lines are distorted in the
vicinity of the slurry trench due to the 200 ft nodal spacing
Transmissivity values of 1 ftday were input at the slurry
locations to simulate an impermeable barrier Tne surface recharge
at those nodes does not infiltrate the relatively impermeable grid
nodes at the slurry locations and flows to the edge of the noae
thus creating a dramatic head loss within a short spacing To
effectively simulate this a variable grid spacing should be used
with reduced node grid spacing at trench locations to eliminate
distortion The computer simulation shows that the slurry trench
could direct flow in the landfill area in a southeasterly direction
and away from endangered wells In addition it would reduce
upgradient infiltration from the stream into the landfill This
measure would prevent leachate from spreading beyond this carrier to
possibly contaminate neighboring wells
The combination of both the slurry wall and impermeable cover
would be ideal measures to minimize generation of leachate and to
stop its spread to neighboring wells The slurry wall without
recharge over it or the landfill is simulated in Fig 31 This
indicates a lower water table tnan eliminating the recharge to the
landfill The slurry wall has blocked upgradient ground-water flow
at its location to the landfill
80
Legend
landfill limit -laquo- j -laquobull excava t ion ^^- stream
copy WNWNEECSESC monitoring well locations
= = = unimproved road ssi slurry wall
f e e t
Fig 30 Slurry Wall
81
Legend
landfill limit j- j- J- excavat ion x-v^gt- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road s==s slurry wall
400
feet
Fig 31 Slurry Wall without Recharge Over It or Landfill
82
An intercepting drainage trench is considered next If a trench
was excavated to a 30 ft depth in the outwash material extensive
shoring would be required In addition difficulties would arise
when the trench was excavated below the waterline Tne trench would
be sloped to provide drainage and backfilled with a highly pervious
material to intercept and divert leacnate locally a conouit which
is perforated on the top to allow infiltration and unperforated on
its lower perimeter to permit continuous drainage to the collection
treatment center would be installed on the bottom of the graded
trench The difficulties involved in excavating below the water
table ano shoring the sidewalls to permit implacement of a drainage
conduit at a 30 foot depth make this option increasingly infeasible
83
Conclusions and Recommendations
The location of the South Kingstown landfill in permeable sand
and gravel glacial outwash material (107 ftday) combined with the
high hydraulic gradient across the landfill area (20 ft1600 ft)
creates a high potential for ground-water contamination to occur
This is intensified because refuse nas been placed below the water
table The low hydraulic conductivity of the compacted refuse (1
ftday) and the excavated area to the west of Rose Hill Road have
both contributed to modifying the original southeasterly flow
pattern These modifications have created a ground-water divide in
the landfill at approximately the western third section Tnis
results in approximately 13 of the leachate flow from the landfill
or 63 gpm flowing in a southwesterly direction and 23 or 129
gpm flows in a southeasterly direction Infiltration from
precipitation recnarge over the landfill (up to 9Upound) and from tne
upgradient stream during low water-table periods provides tne
necessary influx into the landfill Evidence of contamination is
clearly seen on both the east and west sides of the landfill which
reinforces the previously stated flow patterns
Of the several remedial measures reviewed the contouring and
grading of the landfill topcover and drainage swale provides the
most immediate protection The topcover has been graded mulched
and seeded to provide a low runoff slope generally to the east
The drainage swale on the left side of the landfill has improperly
graded sections which should be corrected Its northern section
could be drained into the northern sections swale and the southern
84
section drained to the southeastern section of the landfill Tne
point of the drainage swale which divides the northern drainage
swale from the southern one should be determined by a field survey
Cost is a major contributing factor when determining which
remedial measure is to be applied to the given situation For the
purpose of this report cost estimates are not presented but rather
the effectiveness and feasibility of the remedial measures are tne
primary considerations As was reviewed and simulated in the
computer models the slurry trench and impermeable cover over the
landfill are two viable options that would effectively provide
protection to the domestic supply wells in tne vicinity The
impermeable cover would eliminate precipitation recharge into tne
landfill yet drop the water table only a few feet due to upgradient
infiltration from the stream This would decrease the hydraulic
gradient thus diminishing the potential for a contaminant outflow to
surrounding wells The supply well of primary concern is one to the
west of Rose Hi l l Road marked well D on Fig 2 If contamination
occurs in this well the most effective measure would be to block
off leachate flow in this direction by installing a bentonite slurry
trench at the location indicated previously This would effectively
prevent leachate flow in the westerly direction and diverts it to a
more southeasterly direction In addition the slurry trench
precludes infiltration flow into the landfill from the upgradient
stream
85
Tnis report has effectively reviewed tne original ana existing
flow conditions and contaminant levels in the vicinity of the Rose
Hill landfill The purpose was to provide an understanding of
ground-water contamination patterns and study possiole remedial
measures
86lt
Appendix A
Precipitation Records
Monthly normal precipitation 1941 -197O
i$l Total monthly precipitation
KINGSTON RI
14
ia
^JO T I bullbullL
pound 111 laquobull
4
a
n
-
^
-
-
KS1JAN
^Ii R3 HB MAR
1
1 APR MAY
1
1 JUN
1981
JUL
-bullraquolaquo H
AUO SEP
K3~~f$s bull
_imdash
i1S 1
OCf NOV OtC
171 1 iI1
JAN HB MAR APR MAY
198
Fig 32 Precipitation Record
- - - -
IM 1 MtvJrflgtlgt c ortli-A t lUN I r nraquo rl - -
gt|MO CLIMATOLOQICAL OUSERV ATIONshyr-r bull JK gt raquo - 1
i5fWA I VAPOR Al IOH -bull AIM If MPCRATUM bullF 0 riccipn AT ION UNO IlMf
bull 14 H 14 H mdash Vshy ADDITIONAL DATA IfUAlUS OATt 1 bull raquof bull bull 1 ta
14 Hw rlaquo4 w bullbull bull 1 114 1mdash4 (llrl 1 1 1fl Hll
0 kmdash
Mraquo M4 raquo i T i 4 bullraquo-laquobull i i
Lgt f 1 21 S 1 Hbull - - bullbull -
ltJL 1 2 01 - - _ _ 1
mdash
-
1 12 _ Q I
mdash shy
mdash 4 (C ( - - fVi 1 - 0
1 (1
^ 1
Vvraquolaquo IJ1^ raquo CP O 3L 1 Z - i bull j-t-J
1 J
LH Vb T n 0
1 gt fl oo O ~l 2 L - bull 1 P )laquo jn iP IP - OOI L5L mdash shy
-t 84 ^(^^ ^fi P i flja 0 JO II 10 tl tcgt 7 J IV wllaquo
h l2L bull 0 lt -_ shy
-id VJ lt 3C 2 ft OOL -mdash
U 71 C1 Sr 2 13 2 nl JLJraquopound HP r M ltf1- (
IMe 2 ii O It
n jlt dl 1 1 bull o o-il ST i 1 i 25 2-x-1
-
ri
i tlL O mdash gtbull bullgtlt 1ft -o- is Oil So iJK 2-io otv u 31 fil loi 2 il Oll it Of wr is i1raquo -iZ 1 deg|0 01
M IT So - mdash
- 13 1 CT mdash i - mdash 21
shy
Tl Ci av ZUll IMT 0 IM Pe v _ 1) T) S) ii3( dlt Ii 2 lt^2 II li- S1 riivi To 7HX lt3lO 14 ^2- iTi I li 011 -- - -i -^IS no 5^ or i | T Jift laquoV OoH bullla It Va iCO mdash L OIL 11 bullvf poundgtpound lS_ flv oh P-lfe 1 poif _ shy11 IB kl (4 itlaquoT lamp llt0 oot^
mdash -n
It T1 |ir( L1 HI 2 0 oil
U 1M ft go C ICf^ -^2 Z laquo-|o
11 it 5 bulln - TO o abull Li u-i IT1 -- Iw O ltM (I bullbull bdquo-I(K 1mdash -tilltLlA ttfe
i Dgt ac -- U 44 4 11 1 1- ytd i i_i J-K 0 i if -i i i V t Wl raquoOHM 1-1 US D C P A R T M f N T OF COMMfRCE t 4 1 IUII 1 1 ^~) mdash
llaquo- Hi NC bull bullh bull bullJL^V HBl CO 00
11
)jLsVyr^gturv
^ | TKu
|-_t_ bull(
IIMgt I I Mt|UU III- II 11
PNECIPITATIOH
I 1 1 IMX
IMO
bull llfclaquo I UCIUKI) Ur C V A r U M A AHO CLIMATOUOCICAL OBitH
E V A F O R A T I C r i Jttffl laquo amp hMIlaquoJllaquoJIIlaquoBgt
DATE AOOITIOMAL DAIAKMAKk M
bullraquobullmdashlaquo
tp 01 (1 Of Ll OOI ooo
0^1 o-i 10 tl |00 102
OC (1 13 Ofl
it i rc DS os an
(1 SV o
Ul 010
(ISl 101 I on
130
II 5= Otl
ss lt 001 (IK Ml
jt il HIT
7 it
ow Wo 17 Top 2-01 OIO
(0 oov zi oot
u CO ^A 0 to Zoi CLflS
bull50 01 ljtj
nshy 5H LO OIt
50121 IVO QJO
14 Co Ho LO Hl ^pound Jl 1
ltM ool fllc
H Tl 01 II
11 11 Q1
iH OIO
HO 2 llaquol 11 II
lifc
IV-IIM ul OIPAITHINT or COHMIICC NOAA
NAtlOHAL gtIATnlaquoll raquotraquoVlClaquo CD
r~
All TCUMMATUNI ^V UII rgt ITmi 1 Cwphu Obic i gtn t ngir-H 30
rilCiriTATIOH
JJ T I rTJ-rimdashr-iramj|MP CLmATOLOQ
laquolaquo jftilCiii bullIHO
Oi1l ADOITIOHAL DAIAlllu
Ilf4ft
Sii1
(1 2 IO OO
Hl ii SO
us OIM
Q^L
a A3 Hi SZ Sf^ bull 12J2
HI Z-SF OOl 1C t HM IA H ICP fiJA
OOl 10 (310 sn 310
if HI (0 ^01
bullit SO 28H poundJ1 11 006
14 35 TX oon II (bull2 it zr II c-S
rr Zll lo 31 OP an 31 a 31 oor
CSW O-ll Si CC Of 011
Oll _ I |ft
00
u i oerraquolaquoTMiMr of c NOAA
NATIONAL K C A T N C M SCMVlCC
TC^S lk)oiVroTJA
TETT I 7X
1raquolaquolaquo 4 bdquo ir lt er ni I^OV ltqgl j--^ TQ
MICiriTAllOH ITIND
D|mdash
b5NO ctiUATOtoiCAL oeit^
OATI AOOITIOMAL OATAVlHAtt
0-tt
Mlaquoh bullbullbull- rshy laquo
I- ltltriu HI I 4 bulllaquobullbull1
Zii
30 Dfellt otvt
at HA
OOI
62
iJ_S2 HI if
bull- 20 SI 2i So
So
VVfr
OSfc
I (
Jtlt
3aoi
r j -bull ie MA
Irill iiol
in^ 14
Mo
Zll
214
21 1P
00-i
bulliron
17
bullr
11 i ir- I J Ktf^c
US D E P A R T M E N T OF COuMEDCC I | C gt A A
K AIlaquo Ttupf lATuit r
|SlVi AlJ PIICIPITATION
oJud (El
VIM i Uraquo
MIND E
EVAPORATIOH flnrft bull A ftufiifccdll
KECORO OF eVAPllHAtlil bull I CLIHATOLOOCAL OBSERVA ^Hij
14 MM A_M AOOIIIONAL DATA11 MAIM
Mr bullH Oo|
M Si lift
bull221 IHI
ZS Ji 40 IZV
icr KS I
HZ 111
bullT 21
loA UK JA IP
v^ ft
1M 2Sshy IT Tl
71 V |
i I 31 1deg a
uty^ U bull3
ons 1 CiO TxX
HHO (10
3H 19 12 10 IP
raquo3H raquo | 5t io
OP OIT
14
vO UI Of PANTMINI Or COMMCRCf MM O A A
F ngt TIHH
iiicffwiffc 4 rJ (TIM bull Cempltit Obitittiio
AIlaquo TIMHIATUM PHICinTATION I V A f OK ATlPrl
OATI ADDITIONAL DATA KMAlIt
U4laquo4 +
03H Ji
10
rc a 1 16 oi ii
tiiy 10
OI
II i23 or o 13 -y~ou HO
II 3V III i 3 t
V laquop oot
OM1 SS ne
T an -i IP
Olt zr LTV
3T 001
a -11 2T
10 an 31
-1 raquo 131 UP 3H lf 14 Lpoundshy
it 14 30
IS
Ui O I P A K T M f H T OP COWlf ICfM O A A
NATJONAI V C A T M C n f t K M V l C K
bullbullbullbullbullshy -2 o AIlaquo TIMMRATUM f fKICIPITATIOH
OATI poundt- MMINMAL DATAk
ZP 51 lo icr
011 111
OoT IHf
Ut 003 am
3o 13 ao
4A X 05shy
H4 i IjJyiV131 ooc js
IH oi 01 tL 18 13 a
No 11-7
rivgtp OO| M Hi 03 01
It 12
bull I 41 bull7119 14 ^^ raquo 31 15 lampk n M ho i
Jo -j-
-J
I
Ml H^ I _
amp2ampUi^= LS 0 S 0-f bullTTT
-Vmdash gt U_ bull 1 rOHM I- 11 OI OCPARTMlNT OF COMM(NCC
HO NATIONAL W f A T M f H ftfraquoVlCI
98
Appendix B
Boring Logs
99
X iHECT 1 ff 2
OAT American Drilling amp Bor ini I Co Inc
wo WATH smn EAST PR ov IDENC E ft 1 Town of South Kingstown South K ngstown R I MOLENO X-J
TC 100 RCSS bull ujrMonitorinq Well Installation | South Kinqjtown R I UNC a STA Pf KXICCTHJ LOC ATK3N
bull cfrserrr TO above S MPLES S FNTTO _ _ |laquolaquor A-109 SURF ELEV RE PORTSEr
GROUND WATER O6SE RVATC MS 1 CDREraquolaquo m-T nn75 laquo A 256 - 20 mdash Hew y
Instolled 32ofT-l2 PV C - JO- COMPUTE 111275 K toia 3- I-WI 1-38 TOTAL MRS bdquo10 screen BORING FCACUAM J K lanq MAI rraquo HomnwWI 300 140 IampPCCrc Mamlaquor Fall 24 30 lampaaiona SOLS ENGR
LOCATION OF BORING H ONITOKING WELL
Coung Samplt Tjp Blow per 6 Manure SOU IDENTIFICATION Strata SAMPLE ^^^yV Bloot
foot
Otptni
From- To
el
l
on Sampler
0-6 1 -6-13 12-18
Dentity or
Conmt j
Chang Remark include colo^ graaation Type of tod lie Rao-coMr type condition nordshynetiDntotf time leamt and tie No Pen Rtlt
2 No top sample 5 12
1 loamy fine sand
bull)^ 40 30 36
5- 616 0 23 20 16
noist iense
Brown fine to coarse SAND some fine to coarse gravel Trace silt
^
1 18 18
36 8-0shy57 40 30 V 35
|0-||-6 D 14 24 20 Srown medium to coarse SAND Some fine gravel cobbles
7 IRshy 16
27 75 37 3
IS- I- D 5 14 16 3bull
ISshy 15
42 50 I9--0shy50 65 20-2ll-6 D 9 23 26 bull Jrown fine to coarse SAND Tbullwshy 1Z 75 90
22-0 Trace silt trace fine gravel
124 120 74 60 52 41
7S-ltlaquoil-A DX 71 16 13 wet very dense
Gray-brown fine to coarse SANC Some fine to coarse gravel little silt
H IR u
40 30--0
3C-30-IO
3l4-334
334-3314
38 4-434
D
c
C
C
7 IflO
94 6
we tr j
y se
ft irox
30MOshy
31 -4shy
Gray-brown fine to coarse SAND Trace silt
Gray-brown fine SAND some lilt trace fine gravel
Too of Rock 31 -4shy
Gray-pink GRANITE
6 7
amp
CJ
IltJ A
60
601
IQ mdash
2(
4
5 i Hard
ft 5ome seams bull
GROUND SURFACE TO J 4 U3CD_ ^JVrf bullbull( tutu t to 4o 4 SampM Type Proportion UMd MOB Wtx 3 OfaM on 2OD Sampler SUMMARY-
OOry CCartd WltWen4 Hoc OlolO Canmonieraquoi Don any CoKeem CarMWncy Earm Barrlaquoj 11 14
UPgtUnOigtturod Piuon trite (Oto20dego 0-Kgt Loei it 0-4 Sait 3O+Hofd Rock Corng 14 Kgt-30 laquo4 0 rte 4-8 MSHM Samplet TPTtitPit Ai Auger Vvanefett tarn 2Olo39 3O-M Owlt n laquo-lS Strlf rinit nn v 1
UTiUndlshffbed ThrMOll and bull 33to9O 5O Very 0laquo nraquoe 19-30 V-3trraquof - | OLE NO X-l
TOVH rim - iA it raquotoraquo
100
SHEET 2 o_L
WO WATEt STUET [AST ft OVIDENC pound a i American Drilling amp Bor ing Co Inc
MCLl WQ X- 1 Tt AOORCSS i
LIME A STA KXICCTMJ tuf same as 1 | tame as i LOCATION
W PORTSEf mo OB nj urt eflaquo T
illtPLES S
P
CVTTO nlaquo mun orv
^s f^ Tin i GRCVMO WATER OBSERVATONS CASING SAMPLER CORE BAR
START Typi COMPUTE tome at 1 same aiH
TOTAL MRS BORIMG FOR CMAN n bull IT INSPECTOR SOILS EMM
LOCATION OF BORING u HfVJTneTfi UFI _
8
Counf Blo-t
foot
Dtpllo
From To
0( on SampMr
0-6 f 6-IZ
Moittir
Oonuty or
Contilt
Strata Ctnngc
SOIL OCNTiriCATION Rtmorkt ineHifl cotot grqdotion Typlaquo of Mil etc Roo-axtrPlaquo condition Mrdshynlaquot Drog tun ttomt end tic
SAMPLE
No Ptfl RfK
434-4o4 c
approx 7 minj
per toot 454
Gray pink GRANITE Hard Fairly solid core
lt_4 24
Bottom of Boring 45 -4
-
~
bull 1
GROUND Sorrow Tye
SURHCZ 10
bull OiOry CgtCord WWothod UPUnditiurMd Piston TPlaquoTtraquotPtt AtAuotr VVor
UTltUndinrvd TTMMO bull bulltat
iivnPilaquo(onioni Uraquot4
me OioiOItttt laquoraquo20
wmt Z0ie33
and 361090
c M
C1 5 Si
-SOshy
ASING
IOtgtWtigt bullnlot Dn 10 Loci M Mod 04 SO Dm 1shy Viry 0laquo
s _
TMEN 0 hMl on 200 SoiTBUr laquoity ConcMMt Conorawncy gtbull 0-4 Sort 30shym 4-B MStlfl M BH9 Strtf bull ts-so v-swt bull
t-HOrt Ear Bern RoetCorrt
i ^^^^^ bull
-[MOLE no x-i
101
raquoMEC rAmerican Drilling amp Bor in g Co Inc 1 ofj_ DATE wo WATlaquo smn UST Plaquo IOIDCNC j laquo i
Town of South Kingstown South Kingstown 8 MOLE MO Jlt Z TC rx MCS3
rtprr uAurMonitorina Well Initollation | South KinqitowrxRI UNC A STA P KATIOM ME POCT ^rwT TO above I OFFSZT
uD^r laquorlaquorTTO 6 -109 suw tLEv Sgt louffJOCNO
0 tj Tlmlaquo WOUND WATER 06SCRVATC US gtW Rsdl SING SAM^EH CORE BAH
26 ^_ 12 $TAlaquoT UL 2Z2i Ji r TTP NW ltA sr IJZC Z5 CCOMPLETE
SitLO 3 I-3B- 1-38 TOTAL MAS 41 BOAINO FOACMAN JK1 ana nf ni n MonwwWl 300^ 140 BIT bullK^CT
gttonvrar Foil J^laquo 30mdash Diamond SOOJIEMGM
IE HFII
iCaunq SampM Trplaquo BMMtpw6 UOIIIK- SOIL DCMTIFKATION Siraia SAUPLE Blow DlaquoPIAraquo of on SompMr HtmorU mcJuo cotes gradation Type of Dwuily
pw or CXang writK Roel-eolorlyp condition tvort-From- To Vfoot 0-6 f 6-2 12-18 Coniitt egt rwtiOnAngtimt wamaondtte No Praquon Rtlt
2 Brown fine SAND little silt 2 2-0shy5 15 18 moist Browi fin to coarse SAND 18 5- 6-6 0 14 25 27 vlaquo Troc fin aravel | 25 wy Ifl 11
dlt tns 35 40 38 moist n in-il-i Lgt U 15 18 ie is li1 Irl IS 31 I2-0
~~43 1
A) Jrown coars to medium SAI MD 48 moist Little fine to coarse gravel
|5-IA-Xlaquo 14 47 41 fn D laquo y Little silt rrqa coarse sane 3 18 I1
68 In IS 44 32 34
n ^n-^i-A- w 2o 19 29 wet 4 la -59 lens ltfO no
25-0 2amp bulllaquo- 77 c BOULDER r[ 4 i
27-0 5X ~W 24 24 bullWar- 5 Ifl irown tine to coarse SAND some
dens 29-0- Fine-coars gravel trace silt
30-3I oxx 30 32 30 moist irown -gray fine SANDiom e 6 l rr Vlaquoy 31 -0 silt trace fine oroveTILL
Bottom of Boring 31 -ampbull shyBent casing -pulled out and moved over 4 - washed amp tJrovlaquo casing to 30 -Installed 3C gtof 1-12- PVC - 10 screen
WOUND SUraquoraquofCE TO 3pound 1 yijfD MW t ASIMC TMCJ laquo olaquorod -bor of borina
SomoU T]Fplaquo ProigtuliOraquoH UMd MIOtgtWLx3Orolt lon2OASanlaquoMr SUUMARY-D=Dry CCorad Wlaquoworaquonraquod bullact OiaiO CanM gnMM Daonty CIMIH Caamraquoci EffW 8or^ 2pt
UPiUnairurMd Pition Itnt laquoM2O O- O UKraquolaquo 0-4 Soft 3O-hHard Roelaquo Corrig o- JO M0mlaquo 4-8 MSNff SOTipM 1 p^ 3O-9O OwgtM bull-IS Slid
TPlaquoTraquojraquoPit AAugtr ViVon mini tamt 20to39 UTtundiifir6d TrwMOtf and JSloSO 50-raquobull Vary 0nlaquo [HOLE NO x-2 B-3O V-3Mf lev rim - IAIT raquosectlaquoraquo
102
300 iu 24
1 UMnii ffi 140 laquo 30
CA1INC tf
gt taWCTf
bull 0gtlaquo i R Cook Jr_ R Millineton1 Wttn
I~
1 VAMtl CtMG
1 W HO-t MO
1 Oraquo 1 laquo0~ twt
L 1 laquo-raquo VfcM^lf [wlaquoraquoCI ^ ^ K3Ot III laquo
0-LS D
5-65 D
LlQ 10-115 D
15-16 Tgt
Lraquo 70-51 n
25-26 D
F
I O-O Ci
A Allstate Drill ins Co vi o i
PROVIDING R 1bull raquoraquo uvraquonn~ N M O M I T O P I N G HE1 _^lt -^ PI-Traquo UJU
CUM Town of South Kineraquotown raquoraquo 1 1TA maoer Propolaquolaquod Sit for Slude Disposal nltn
laquo V-449 iampAAtut i a 138 ort STI bull r 42777 CtOuMO IKVtllON
Cill bdquo 258 DA II MN ru 42777 rilaquolaquodO laquoraquoTti rum 1911
AU1TATI
MMUI1 raquolaquogtlaquolaquo laquoKiO itXHHKraquoriOi of sous MUAHI nMTKlion Ot CMlaquoMC|kOraquort tl CO~VH DXltgt raquomlaquo laquotf IMi COIOI C4l II I 1raquo gtlaquo^ Oraquo 1Ol rC t Xgttgt VtfKOe Craquo Mi 1 ft liMraquoK laquo0^tlaquot nfgt
1-2-1 10 TOP SOIL FINE LIGHT BROWN SAND traclaquo of ilt
16-31-17
22-24-21 100 FINE TO MEDIUM LIGHT GRAY SAND trace of fine gravlaquol and raquopoundLt
lfl-37-34 150 LIGHT BROWN FINE TO MEDIUM SAND little poundinlaquo gravel
21-17-15 200 MEDIUM TO COARSE SAND bullomc fine gravel
12-4-10
265
Observation well installed
NOTE No casing blows taktn
bullbull B-23 ow
^w^ 265 I raquo bull raquolaquo bull I W
11 laquot gtbullraquo Vlaquo 14 W gt_ c-shyji bull alaquo bull jraquo VI laquoHshyw bullbull m raquobullbull D-6 raquo Mshy
bull bull laquo Vshy
1
bull bull
I
103
MAMMII Allstate Drilling Co ulaquorr 1 or 1 FftOVIOCKZ H L traquolS mTArm^S MONITOR NR WEL
VNO wr3JJO__raquoraquou_24__ HCU MO P-74 n iu riBwi Town of Slt7H^ Xirpin
mdash^ laquo0J P 1 1 bull ^n^ciit^o TVlaquow^laquott1 bullraquoit wt 140 nu 30 olaquor fBu lkv Waste Disposal Arcai
MUTAH a V-449 R Cook Jr UMlaquoiigti D 1 38 0t| raquoIJ raquo 5277 rlaquo SUMO luvlaquorv-laquow
mdash 5277 fipe -raquoT pfpm 150
H MCIO IMNTlXAflON Of SOU t(kAIlaquoS rrn 0-laquoraquo
5 -SF 01 w in laquobull -raquo ^ lit
D 1-2-2 TOP SOIL V-1-oraquo
15 IPbull FINE TO MEDIUM LIGHT GRAY SAND AND GRAVEL
5-65 D 37-27-35 some silt
10-11 D 20-14-18
15-165 D i 17-14-14 155
BROWN COARSE TO MEDIUM SAND little fine to coarse gravel trace of silt
20-211 D 4-4-2
230 GRAY BROWN VERY FINE SAND
25-26J D 7-8-9 AND SILT 265 fvarvedl
Observation well installed
NOTE No casing blows taken
wta 10 n uuraquo c^imdashbull IgtM laquolaquobull- B-24 ow ~ 14 ltfc laquoraquobull vlaquo^ M laquobull r O 0 fmtt bull W-L 26 5
-0- CgtCmdashgt bull laquolaquobull mdash laquo 1 - raquoraquo 1 gt 1laquo bull 1 gtraquor to bull mdashbull bull bull bulllaquo I t l~laquo 1lt Uraquo mdashbull ) bull 1 gtbull ft 0~ H laquoy bullM ta bull -IN la laquobull OPUM bull($ IMI
mdash H raquo laquo-bull
104
Appendix C
Calibration of Specific Conductance Meters
105
Specific conductance measurements were made using a beckman RB
338 temperature compensating meter and a YSI rtooel 33 salinity
conductivity temperature meter The YSI meter is not
temperature correcting A formula to compensate for temperature
differences to standardize YSI measurements was used (21)
A long probe for the Beckman meter was used to measure conductivity
in the wells Differences in conductivity between the YSI ana
Beckman meters and the Beckman short and long probes exist These
were calibrated in the laboratory using 001 N and 01 N KC1
solutions Values presented are Beckman short probe values The
Beckman long probe values were reduced by 76 and tne YSI values
were multiplied by 11 to adjust to Beckman short probe values The
YSI meter was used in the latter phases of the study for the
stream contamination due to the greater accuracy of the dial readout
scale
Table 7 Specific Conductance Meter Calibration Table
Concentration (KCL) 0001N 001N
Specific Beckman short 145 143 143 1247 1245 12GO
Conductances Beckman long 190 191 188 1639 1650 1665
umhocm 9 25 C YSI 132 131 128 1131 1140 1150
average values Beckman shortBeckman long = 075
Beckman shortYSI = 11
106
Appendix D
Computer program Flow Chart
107
F1g 33 Computer Program Flow Chart-
1TpoundR MAP TCO
NEWPER
WEWSTP CZAX
HEWIT TRANS TCOF ROW COLUMN
Yes
Yes
108 The following is a description of the USGS two-dimensional computer
program Iterative Digital Model for Aquifer Evaluation updated
December 1972 by P C Trescott The program written in Fortran
consists of a MAIN program and six subprograms or subroutines which
themselves are organized into subprogram sections The subroutines and
their sections are listed below
MAIN Program
DATAIN (subroutine) COEF ITER (section) CLAY MAP TRANS NEWPER TCOF
ETRATE COMPUT STORAG
NEWSTP LEAKAG NEWIT1 NEWITO CHECK ROW CWRITE COLUMN STEADY PRNTA OUTPUT DRY BLOCK DATA
The program begins in the MAIN program which controls the sequence
of passage to the subroutines Sequential steps are described in the
program as shown in the flow chart of Fig 32 Emphasis is placed on the
steady state confined aquifer case as applied in this study First data
input is read in the DATAIN subroutine This data includes transmissivities
or permeabilities starting heads storage coefficients and grid spacings
Nodal transmissivity values are then computed for the water-table problem
in the TRANS section (COEF subroutine) This procedure is necessary here
because the subsequent routine for computing iteration parameters (ITER)
keys on nodal transmissivity values which would not have been input to
the water-table problem In the water-table option these would have been
109
computed from given bedrock and water-table elevations to obtain the
saturated thickness component of the transmissivity calculation In this
study water-table option was not used and the transmissivity values were
input directly The program then passes to the ITER section (DATAIN
subroutine) to compute the iteration parameters which expediate or even
cause convergence Next the MAP section (DATAIN subroutine) is utilized
to initialize data for an alphanumeric map if this was requested in the
input options Transmissivities are then computed for the confined
(artesian) aquifer case (water table not specified with input options)
in the TCOF section (COEF subroutine) These coefficients are harmonic
mean values of adjacent nodal transmissivities weighted by grid sizes
Time parameters and pumping data for a new pumping period are then read
in the NEWPER section (DATAIN subroutine) followed by entry into the
NEWSTP section (COMPUT subroutine) which calculates the size of the
time step Leakage coefficients (hydraulic conductivity of the confining
bed divided by confining bed thickness) are next computed in the CLAY
section (COEF subroutine) if leakage was specified in the input data
which was used in this study
A new iteration is then initiated in sections NEWITO (COMPUT
subroutine) NEWITO saves the current head values and compares them to
the updated head values for determining closure This is followed by
nodal transmissivity values being computed for the water table or water-
table artesian conversion problem Transmissivity coefficients are then
computed for the water-table problem in TCOF (COEF subroutine) Total
head values are then computed with the alternating direction implicit
procedure using the Thomas algorithim first along rows in the ROW section
110 and then along columns in the COLUMN section both in the COMPUT subroutine
Then if a solution is not obtained (because the error criteria for
closure is not satisfied) the MAIN program branches back to NEWIT1 subshy
sequent sections TRANS TCOF ROW and COLUMN repeatedly until a
solution at the particular time step is achieved NEWIT1 increments the
iteration counter and is immediately followed by NEWITO The program then
moves to the STEADY section of the COMPUT subroutine to check if the
closure criteria for steady state has been satisfied Output is then
printed in the OUTPUT section of COMPUT if steady state has been reached
or if the particular time step is designated for output
The program then branches back to NEWSTP (COMPUT subroutine) and
moves through the subsequent routines until the last time step in the
pumping period is reached Output is then promoted in the DRY section
of COMPUT if specified in input data If the last pumping period in
the problem has not been reached the program branches back to the
NEWPER section and moves again through subsequent sections otherwise
the program will terminate or start a new problem if one follows
This study was simulated as a steady state problem which can be
simulated by setting the storage coefficient of the aquifer and the
specific storage of the confining bed to zero and using one time step
of any length
111
Appendix E
Computer Data Sheets
RGSEA
10 ROSE HILL LANDFILL MODEL 20 30 40 LEAKAGE 50 60 70 CHECK 80 90 100 HEAD 110 120 1 23 IQ 100 5 001 37E-OU 0 130 100 001 0 0 1 4 0 - 1 - 1 1 - 1 - 1 i i i i i i 1
ISO 1 10 0 1547E-05 01 10 1 1 160 04642 200 200 1 1 i it
1QO 190
CARDS I THROUGH 19 - CODING SHEET
CHEAD
100 110 120 130 131 132 140 141 142 150 151 152 160 161 162 163 164 165 170 171 172 173 174 175 176 177 178 179 1BO 101 190 191 192
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 539
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 58
25
25
25
25
25
25 621
25
25
25
25
25 662
25 25
25
CARD SET 2 - STARTING HEAD MATRIX (FT)
193 194 IVb 196 197 190 200 201 202 210 211 212 220 221 222 223 bull 224 225 230 231 232 233 234 235 236 237 23B 239 240 241 250 251 252 253 254 255
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 23 25 25 25 25 25
25 25 - 25 25 25 25 25 25 25 25 25- 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 - 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25
25 25
25
25 25
25 25
25 25
25
25 25
25
25 25
25
25
25
25 25
25 25
25
25 25
25 25
25 25
25
25
25 25
25
25 25
CARD SET 2 - STARTING HEAD MATRIX (FT) - continued
STORC 1512 FRI 19 FEB 82
100 110 -1 -1 - 1 - 1 0 0 120 130 140 ISO 160 170 100 190 200 210 220 230 240 230 251 260 261 262 263 270 271
CARD SET 3 - STORAGE COEFFICENT
LEAK
100 110 120 02 130 _ 18 02
I ltu 18140 025 150 02015015015 19 deg25
02 160 022 bull-laquo- J1 5 j 1 z laquo- l^
170 015 180 016 laquo02
190 016 OE025
200 02504019022021025 2 5 i S lt03 0252i2 n
230 030 deg23 deg2 deg2 deg2 -02023023 240 022 250 022025025 02
027043 013025
30() 025025025 310 025031 320 024025
CARD SET 5 - AREA OF STEAMBEDAREA OF NODE
120
Appendix F
Bibliography
121 BIBLIOGRAPHY
1 Agpar MA and 0 Langmuir Ground-Water Pollution Potential of a Landfill Above tne Water Table Groundwater V 9 No 6 1971 pp 76-96
2 Allen William B Hahn GW and RA Brackley Availability of Ground Water Upper Pawcatuck River Basin Rhode Island USGS US Government Printing-office GS 66-624 19bb
3 Annual Book of ASTM Standards Part 31 Open Channel Flow Measurement of Water and Waste Water by Weirs D 2034-68 1975
4 Annual Book of ASTM Standards Part 19 Infiltration Rate of Soils in Field Using Double-Ring Infiltrameters D 3385-75 1975
5 Baeaecner MJ and W BacK Hyarogeological Processes and Chemical Reactions of a Landfill Ground Water V 17 no 5 1979 pp 429-437
6 Beck WW Dunn AL and Grover H Emrich Leachate Quality Improvements After Top Sealing1 8th SHwRD MERL Symposium 1982
7 Beckman WK Transient Modeling For Estimating Sustained Aauifer Yield master thesis presented to the University of Rhode Island Kingston RI 1978
8 Bhattacharya PK and HP Patra Direct Current Geoelectric Sounding Elsevier Publishing Co New York 1968 135 p
9 Bouwer H Ground Water Hydrology McGraw-Hill Book Co New Yoric 1978 p 378
10 Braids 0 Cocozza pound Fenn D Isbister J Rous P and B Yarc Procedures Manual for Ground Water Monitoring at Solid Waste Disposal Facilities Environmental Protection Agency530SW-611 Cincinnati Ohio 1977
11 Cartwright K and MR McComas Geophysical Surveys in the Vicinity of Sanitary Landfills in Northeastern Illinois Groundwater V 6 no 5 1968 pp 23-30
12 Cartwright K and Fd Sherman Jr Electrical Earth Resistivity Surveying in Landfill Investigations Reprinted from Proceedings of ohe lOtn Annual Engineering and Soils Engineering Symposium Moscow Idaho 1972
122 13 Clark TP Survey of Ground-Water Protection Methods for
Illinois Landfills Groundwater V 13 no 4 1975 pp 321-331
14 Dunne T and LB Leapold Water in Environmental Planning WH Freeman and Company San Francisco 1978
15 Faro DG Upgrading Hazardous Waste Disposal Sites Remedial Approaches US Environmental Protection Agency500SW-677 Cincinnati Onio 1978
16 Fenn DG Hanley KJ and TV Degeare Use of the Water Balance Method for Predicting Leachate Generation From Solia Waste Disposal Sites US Environmental Protection Agency530SW-lfa8 Cincinnati Ohio 1975
17 Geisser 0 An Electric Analog and Digital Computer Model of the Chipuxet Ground Water^ Aquifer Kingston Rhode Island master thesis presented to the University of Rhode Island Kingston RI 1975
18 Hahn GW Groundwater Map of the Narragansett Pier Quadrangle Rhode Island Rhode Island Water Resources Coordinating Board GWM 5 1959
19 Hemsley William T Koster C Wallace Remedial Technique of Controlling and Treating Low Volume Leachate Discharge USEPA National Conference on Management of Uncontrolled Hazardous Waste Sites Oct 1980
20 Hughes GM RA Landon and RN Farvolden Hydrogeology of Solid Waste Disposal Sites in Northeastern Illinois Final Report to US Environmental Protection Agency PUD SW-l^d Cincinnati Ohio 1971
21 Keller GV and FC Frischknecht Electrical Methods in Geophysical Prospecting Pergamon Press New YorK NY 19bb
22 Kelly WE West Kingston Landfill An Evaluation of Its Effect on Ground-Water Quality Rnoae Island Water Resources Board Water Information Series Report 1975
23 Kelly WE Geoelectric Sounding for Delineating Ground-Water Contamination Groundwater V 14 No 1 1976 pp fa-10
24 Kelly WE Ground-Water Pollution Near a Landfill ASCE Environmental Engineering Division Journal V 10 No EE6 Dec 19b pp nay-nyy
25 Kelly WE personal communication January 1982
123
26 Kelly WE and OW Urish A Study of the Effects of Salt Storage Practices on Surface ana Ground Water Quality in Rhode Island NTIS FHWA-RI-RD-8001 1981 54 p
27 Kimmel GE and OC Braids Leachate Plumes in a Highly Permeable Aauifer Groundwater y 12 no 6 1974 pp 388-393
28 Klefstaa G Senalein LVA ana RC Palmauist Limitations of the Electrical Resistivity Method in Landfill Investigations Groundwater V 13 No 5 1975 pp 418-427
29 Landon RA Application of Hydrogeology to the Selection of Refuse Disposal Sites Groundwater V 7 no b 19b9 pp 9-13
30 Lang SM Bierschenk WH ana WB Allen 1960 Hyaraulic Characteristics of Glacial Outwash in Rhode Island Rhode Islana Water Resources Coordinating Board Bulletin No 3
31 LeGrand HE Patterns of Contaminated Zones of Water in the Ground Water Resources Research v 1 No 1 1965
32 Palmauist R and L Sendlein The Configuration of Contamination Enclaves from Refuse Disposal Sites on Floodplains Grouna Water v 13 no 2 1975 pp 167-181
33 Pinder GF A Digital Model for Aauifer Evaluation Techniaues of Water Resources Investigations of the US Geological Survey Bk 7 Cl 1970
34 Purushattam D Tamxe GR and CM Stoffel Leachate Production at Sanitary Landfill Sites ASCE Environmental Engineering Division Journal V 103 no EE 6 Dec1977 pp 981-988
35 Remson I Fungaroli AA ana AW Lawrence Water Movement in an Unsaturated Sanitary Landfill ASCE Sanitary Engineering Division Journal v 94 no SA2 April1968 pp 307-316
36 Rosenshien JS Gouthier JB and WB Allen Hydrologic Characteristics and Sustained Yield of Principal Ground-Water Units Potowamut-Wickford Area Rhoae Island USGS US Government Printing Office GS 67-324 1968
37 Roux PH and B Vincent Electrical Resistivity Evaluations At Solid Waste Disposal Facilities US Environmental Protection Agency SW-729 Cincinnati Ohio 1978
124
38 Salvato JA Wi lk ie WG and BE Mead Sanitary Landfill Leaching Prevention and Control Water Pollution Control Federation Journal v 43 no 10 Oct 1971 pp 2084-2100
39 Sawyer CN and PL McCarty Chemistry for Environmental Engineering McGraw Hill 1978
40 Stellar RL and P Roux Earth Resist ivi ty Surveys - A Method for Defining Ground-Water Contamination Ground Water v 13 no 2 1975 pp 145-150
41 Todd OK Ground Water Hydrology John Wi ley and Sons Inc New York 1959
42 Tolman AL Ballestero AP Beck WW and GH Emrich Guidance Mannual For Minimizing Pollution From Waste Disposal Sites US Environmental Protection Agency-500SW-677 Cincinnati Ohio 1978
43 Trescott PC Iterative Digital Model for Aauifer Evaluation US Geological Survey Open file report 1972
44 University of Rhode Island Academic Computer Center CalComp Contouring Manual
45 Warner DL Preliminary Field Studies Using Earth Resistivity Measurements for Delineating Zones of Contaminated Ground Water Groundwater v 7 1969 pp 9-16
46 White EF A Report to the Town of S Kingstown Utility Survey Engineering Corp 1967
47 Zohdy AAR A Computer Program for the Calculation of Schlumberger Sounding Curves Over Horizontally Layered Media Using the Method of Convolution US Geological Survey Denver
48 Zohdy AAR Eaton GP and DR Mabey Application of Surface Geophysics to Ground-Water Investigations Technidues of Water-Resources Investigations of the US Geological Survey Book 2 Chapter 01 Washington US Government Printing Office 2401-02543 1974
Vl l
List of Figures
Figure
1 Location Map 2
2 Study Area 3
3 SupplyWel l Locations 4
4 Field Grouna-Water Table Contour Map 5
5 Ground-water Map 12
6 Geology Background Map 13
7 Fluctuation in Water Level in W e l l s 16
8 Seismic Survey Location 19
9 We i r Locations and Water Level Ranges 21
10 Surface Contamination Monitoring Locations 24
11 Fluctuation in Specific Conductance in W e l l s 25
12 Electrical Resist iv i ty Sounding Location 28
1 3 Model Grid 31
14 Simulated Ground Water Table Contour Map 32
1 5 Northern Drainage Area 34
16 Landfill West-East Cross-section between Wells W and EC 39
17 Landfill North-South Cross-section between Wells NW and SC40
18 Natural Conditions 43
19 Excavation without Landfill 45
20 Landfill without Excavation 46
21 Landfill Head Contour Cross-section 47
22 Landfill and Excavation with Dam 49
23 Summer Condition 52
24 Landfill ana Excavation without Dam 54
VI 1
25 Infiltrometer Location and Drainage Feature 57
26 Results of Infiltrometer Tests 59
27 Schlumberger Sounding R-l 71
28 Schlumberger Sounding R-2 72
29 No Recharge over Lanafill 77
30 SI urry Wall 80
31 Slurry Wall without Recnarge Over It or Landfill 81
32 Precipitation Record 87
33 Computer Program Flow Chart 107
Introduction
Ground-water contamination of aauifers from municipal landfills
is a widespread problem Contamination of domestic supply wells and
neighboring streams has occured at the South Kingstown municipal
landfill which is located adjacent to Rose H i l l Road approximately
one mile nortn of Peace Dale Rhode Island (Fig 12) The polluted
neighboring wells have been relocated to their present locations to
remove them from tne leacnate plume (Fig 3) Fig 4 inaicates flow
patterns from the landfill which has contaminated streams to the
east and southwest of it The generation of leachate continues as
precipitation recharge and upgradient ground-water sources
infiltrate the refuse To effectively prevent or minimize
contamination from this landfill several remedial options are
available These w i l l be evaluated relative to the areas geologic
setting and hydraulic properties ground-water flow patterns
recharge characteristics and proximity to supply sources
The rate of ground-water flow out of the landfill into the
adjacent aauifer and flow patterns largely depend on tne hydraulic
gradient of the water table and the hydraulic conductivity of the
landfill and aduifer material The hydraulic gradients were
determined by monitoring water-table fluctuations in several wells
located around the landfill and elevation siting in stream
locations and elevations This information enabled a ground-water
map of the area to be developed from where flow patterns can be
developed assuming flow lines are orthogonal to contour lines The
ground-water map in combination with Knowing aquifer and landfill
N
^ooo
feet
Fig 1 Location Map
3
peoy ||H asoa
X ltbull
Alt
f c c
o
^ ^ o o f a
O OJ 83X1
o O
x o
seepage observation -t West
hole Landfill Area
Legend mdash landfill limit bull j--excavation limit r^-s stream copy WNWNEECSeuroSCSEN
monitoring well locations = = = unimproved road
A contaminated domesti supply well
D uncontaminated domestic supply well
feet
Fig 3 Supply Well Locations
5
a 03
N lo ^ gt
laquo c 2
mdash w
3
X o ^
3 O L
o CO
0 opound E bullo
0
co
c
o0
uj ^
0 o o c
o $ bullA
E c o
w
bullo t_hraquo9 O
_OplusmnJ ca
u
pro
ve I 51 H
bullo 0gt
UJ _c e poundbullo Mzbull w gt 0
laquorege cc
0gt -^^ o a5 raquobull bullo o sect 3 mdash laquoo o wcz _
3Ogt c $c o_ X
aw e 05 0 (0 3 bullo
o a 2 2 u
hydraulic properties and the subsurface geometry enable estimates of
ground-water outflow to be made Streamflow measurements were used
to verify these outflows Contamination levels using specific
conductance measurements as an indicator were measured in wells
streams and observation holes to help delineate the extent ana
degree of contamination An electrical resistivity sounding was
conducted in a known contamination zone
The primary objective of tnis study is to determine flow
patterns in the vicinity of the landfill ana recommend possible
actions to contain or minimize the impact of the contamination In
oraer to fully evaluate these goals the aforementioned parameters
were input to a computer model to produce simulated flow patterns
under different conditions The simulated present conditions were
matched with field water table and stream flow measurements to
calibrate the model A series of simulations were then run to
evaluate flow conditions before the excavations anaor landfill
existed Remedial measures such as reducing recharge to the
landfill and implementing a slurry wall to blocx off leachate flow
to endangered wells were simulated to evaluate their effectiveness
Based on this analysis recommendations are made as to how to
minimize leachate production ano best alleviate the immediate danger
of the contaminant plume spreading to unpolluted domestic supply
wells
background
The South Kingstown landfill is in a geologic setting that is
very similiar to the nearby West Kingston landfill This is located
about 3 miles west of the South Kingstown landfill and has been
studied to assess leachate effects on groundwater quality using
specific conductance as an indicator of contamination levels
(222ltt) Both sites were located in abandoned gravel Quarries which
were filled in with refuse to create the landfill
In the literature numerous authors have shown that the character
of contaminant plumes from landfills are largely dependent on the
local geology and geohydrology A study on Long Island (27) in
similiar glacial material illustrates that the Quantity of flow is
dependent on the hydraulic conductivity of tne aauifer the
hydraulic gradient and the vertical cross-sectional area of the
aauifer it flows through This is expressed as Darcys Law (41)
Q = KIA
wnere Q = flow quantity
I = hydraulic gradient
K = hydraulic conductivity of the aauifer
A = vertical cross sectional area of the flow area
Specific conductance was used as a contaminant tracer to show that
the plume from the landfill flowed downgradient and vertically
through the full thickness of the aauifer A study in Iowa (32)
indicates that the size ana shape of the contamination outflow from
a l a n d f i l l can be predicted from existing geohydrologic conditions
and that the horizontal shape of the outflow extends downgradient
8
from the source and parallel to ground-water flow lines Other
parameters which control the extent of the contaminant plume are
dilution and dispersion in the aquifer and the adsorption properties
of the aauifer material (31)
The amount of leachate generated depends largely on the amount
of water that infiltrates through the landfill to increase tne water
content of the refuse in the landfill The precipitation recharge
that percolates down through the unsaturated zone to the water table
moves in a vertical direction (35) Surface runoff soil moisture
storage losses and evapotranspiration account for tne precipitation
that is not transmitted tnrough the unsaturated zone of aeration
(3315) Upon reaching the saturated zone the water enters the
ground-water flow system Ground-water mounding has been reported
in landfills due to the decreased hydraulic conductivity of
compacted refuse relative to surrounding aauifer material (20)
Chemical processes within the landfill leachate outflow and
surrounding soil cation exchange capacity relative to water duality
of the surrounding aduifer have been studied in Pennsylvania (1) anu
in Delaware (5) A procedures manual for ground-water monitoring at
solid waste disposal facilities was developed by the US
Environmental Protection Agency (USEPA) (9)
Several reports have been written that investigate site
selection design criteria and remedial measures to correct
leachate problems (29) A survey of ground-water protection methods
for landfills in Illinois studies relationships to the water table
theory of liner installation and monitoring devices (13) Sanitary
Landfi11-Leaching Prevention and Control presents a review of
preventative methods such as means to minimize infiltration
interception of ground-water and other pollution control measures
(2 37) A study in Pennsylvania on actual measures implemented to
collect and treat a landfills leachate discharge presents a site
specific study (19) Leachate Quality Improvements After Top
Sealing1 shows that by minimizing infiltration at a landfill in
Connecticut the outflow leachate water quality can be improved
dramatically and contamination plume reduced significantly (6) The
most comprehensive reports on remedial approaches to upgrading waste
disposal sites and ground-water protection methods have been
compiled under USEPA contract (1542)
To assist in evaluating remedial measures the US Geological
Survey (USGS) computer model Iterative Digital Model for Aduifer
Evaluation was used It was originally developed as a model for
simulating two-dimensional aauifer problems (33) It had been
updated since its original development to accomodate different
options (43) This model has been applied to glacial outwash
regions in Rhode Island (717)
10
Description of Study Area
A map of tne landfill area (Fig Z) was obtained from tne town
of South Kingstown The excavation to the west of Rose Hill Roaa
the landfill area directly to the east and the presently operating
area to the east of the central stream comprise tne overall study
area This study will concentrate on the west landfill area whicn
has recently reached capacity and been closed to further dumping
This site received mixed refuse for the past 15 years The depth of
the excavation where the landfill presently exists was approximately
to bedrock in some places Tne exact depths of landfill material is
unknown
The landfill cover has been graded and sloped generally eastward
to convey surface runoff to the eastern side A sandy soil that was
excavated locally was used as tne cover material The northern
section has a vegetation cover and the recently filled southern
section has been seeded and mulched The six monitoring wells W
NW NE EC SE SC were placed by the town of South Kingstown to
provide water quality information
Referring to Fig 2 the west excavation stream drains the area
created by the excavation to the west of Rose Hill Road and flows
throughout the year The central stream drains a small watershed
area which lies to the northwest of the landfill and drys up during
part of the year These streams flow into the Saugatucket River
which flows throughout the year and is larger than the west and
central streams combined
11
The USGS Groundwater Map (18) was initially consulted to proviae
information on the ground-water flow patterns (Fig 5) and the
geology of tne area (Fig 6) The surficial geology borings and the
vertical geologic cross-section at the base of the study area
indicate shallow water table and bedrocic and a nearly constant
saturated thickness (18) Boring logs at the W well ana a point
approximately 150 feet south of it indicate glacial outwasn material
which is primarily sana with a trace of gravel over bedrock at a
depth of approximately 33 feet Borings at the east landfill area N
and S monitoring wells indicate the same aquifer material
(Appendix B)
The ground-water map developed by Hahn is taken as
representative of conditions existing prior to the excavation of the
I l andfill (18) This indicates water-table contour lines that run in i
a general northeasterly direction This means tnat flow was
originally in a southeasterly direction However contamination of
domestic supply wells on the west side of Rose Hill Road has
occurred (Fig 3) strongly suggesting that the original flow pattern
has been altered by the excavation to the west of Rose Hill Road and
the landfill to the east of it Domestic supply wells were formerly
located directly to the west of Rose Hill Road but were aoandoned
when they became contaminated from landfill leachate New wells
were located to the south and west away from the contaminant plume
of tne landfill In addition a well located at the northeastern
corner of the landfill was contaminated and a replacement located to
the east of Us former location on tne opposite side of the central
12
Legend scale 124000
mdash-40 mdashground-water contour elevation
Fig 5 Ground-Water Map
13
Legend feet
TILL
Fig 6 Geology Background Map
14
stream This second wel 1 also became contaminated Domestic supply
wells located near tne northwestern corner of tne landfill and
approximately 300 feet south of it nave remained uncontaminated
These well locations serve as an indication of tne extent of the
landfill contamination which is largely dependent on the groundwater
flow patterns To furtner investigate this problem and provide
substantial information on which to base the geohydrologic analysis
field studies of the area were conducted
15
Field Studies ana Procedures
A map of the lanafill and an aerial pnotograph of the area were
obtained A tracing of these maps superimposed upon another
delineates stream landfill and monitor well locations (Fig 2)
The field investigation concentrated on the west landfill area ana
its aajoining streams ana monitor wells The east landfill area and
the three monitor wells in that area are induced in the latter
phase of the study in oraer to expand the model area
A traverse which establishea tne monitor well elevations was run
using a Carl Zeiss level These were originally sitea in by the
town of South Kingstown using a local USGS reference datum number 40
(18) The wells of known elevations then served as benchmarks for
referencing adjacent stream elevations This in combination with
the depth to water table measurements at each well enables tne
water-table surface geometry of the area to oe visualized
Water-table measurements of the west landfills wells were recordea
over a ten month period to record fluctuations (Fig 7 Table 1)
The east landfill areas wells were monitored for a five month
period Using a given water-table condition a ground-water map was
developea of the area (Fig 4) This indicates an outflow from
the landfill primarily in a southeasterly direction and partially
in a southwesterly direction
Additional bedrock and water-table information was ootainea by a
seismic refraction survey at several locations along the landfill
perimeter A Bison Model lb70C Signal Enhancement Seismograpn was
used to maxe the surveys Lines were run (to a length of kOO feet)
16
17
w s p bdquo S bdquo s S S a laquolaquo _
s 2 8
V
r bdquo
3 s a
-R s
S
S 3
t
raquobullraquo
S
5
K
r
~
3
K
pound
7
S
bdquo3
C 5 S
shy raquo S s
1 3 s 3 2 5 ^ bull
5 m
s o
^ 3
raquo
--
R bull 5
s pound J O s
5 a 3 7 3 m
5 s a ^
iraquo a s rlaquo
M ^
^ c o 2 5 s 3 a S R
rd 3 y a O =J
^ bdquo
JJ s s 3 bull ~ I
~ s 5 3 a s a
(Ogt (U
2
-t =
r s s in
5 y
a s
5
3
s
5 a
^ a
3 a 51 a bullbull
sj 5 Ml
3 a bull
s raquo
a
0)
0
^ mdash
a j -
-3
C
g S
S
bull a
-
~ 3 o
2 s s 3 a bdquo s s $ Al s
(1) = $ s 3
S
c a a
3 e 5 s N s S a - 3 = s s a 5
a s s - 3 S shy
4
0
a s
bdquo tfH
bdquo
3 a
bdquo
s a
e bullfl s i s s a s a
3 nt
s s 3
g laquo s3 a
~ J s 2 a s o s S s 3 a a j laquo s o s
3 bull laquobull
2 a 7 3 a 3 a ^2
s mdash 5i o
bull bull
mdash
3 o
ss a
fc mdash
3 1-sect m ishy n
18
in both directions to provide a check and permit accurate estimates
of the depth to bedrockThe seismic results allow approximate
interpretations of the depth to the water table and bedrocK thus
permitting an estimation of the saturated thickness Ground
elevations at the location of the seismic surveys were determined
from a topographical map and field siting From this information
water table ana bedrock elevations estimates were made Bedrock
contours are listed in Fig 8 In addition a table which
summarizes the seismic refraction results for the unsaturated
saturated and bedrock layers velocities and depths at each survey
location is presented in Table 2
Scream gauging stations were established on the two streams
bordering the west landfill (Fig 9) Three stations were placed on
the central stream These provide information on the influent or
effluent condition of ground-water flow in the upper sections of the
stream and ground-water baseflow from an area adjacent to the
landfill into the stream (Table 3)
The stream gauging stations used were 90deg V-notch weirs The
weirs located in the SE and SW positions were placed in the
streamoea with a liner of plastic upstream to minimize underflow
The weirs located in the NW and E positions were cut to fit in
recesses of concrete culvert pipes Concrete plywooa interfaces
were coated with roofing cement to minimize bypass flow Upstream
water pressure and a snug fit hold the plywood sections in place
All weirs were implaceo according to AigtTM reouirements and flowrates
calculated using the standard 90deg V-notch formula (3)
19
N
seepage West observat ion Landfill hole
Area
Legend landfill limit excavat ion limit
copyWNWNEECSESC monitoring well locations
= = = unimproved road -- WNES-number
seismic refraction locations
-40shy approximate bedrock contpur elevation
feet
Fig8 Seismte Survey Location
20
c ^-^ c4j ^laquoc in -=r 3shyjj bull pn f- 4-gt bull in in OjJ bull bull a jo bull bull O JJ
co CM o on on CO CM CTNVO VO co CM o on on Q gt_x rH oj on a oj on a - rH oner
rmdash on sr i i
M z Z
gt gt gt
X-N CO laquomdashv CO CO bull igt gt bull
1 gt fc^gtgt bullbull ^ ^ ^
C 4-gt O t igt O J- 4J O H m o o o 3 bullH CO O rH in 3 bullH co vo o in 3 ~ 1 i-k -i ^trade fj rj ui ij o CO o n o rH =r co o n vo vo vo co o bullv O O O
O raquo On-3 rH O -bull- rH ON in _ IH in oj - rH bull rH VO OrH bull rH On ON pH d)u CO -UCO 4J OJ CO 4-gt gt
C mdashbull gt CM gt CM H-l O CO
v- ^^ N C 0
bull0 N CO
4-5 -0 _c^gt in in CO CO
C x~ c -^ t-oo in i 4J j_gt 41 4J bull 9 bull bull 4J bull
o j ON O O 3 (0 O4J O ON ON QJJ t~-^3- OJ 4-gt L
CO CM trade CO CM rH rH OJ co CM oj on Q ^ _ CO 3~Q-- n 45 Q mdash OJ OJ OJ C (0
1 11 3 nZ 2CO
gti gt gt CO CO CO ^-x m -s CO
rH rH ^ ro^^ bull gt bull ^ igt gt bullgt gtgt bull r O -Q 4Ji JJ O 5- JJ O pound- ^ O 4) oj o on (0 CO
3 bullH CJ O O in 3 bullH CO Cmdash VO on 3 pound-laquo H CO o n in inco co o n ma- r co g^ 5sect^ o
o rH on oj O bull- rH ONCO L O_ rH OJ VO M
rH bull rH =t rH bull - OJ T CO CO M CO 4-gt rH CO -U rH CO 4-) s
uits
CO 4-gt 4-5 T3 gt CM gt CM gt CM cc CO CO CO
3 3gt oa tlp^ CO O CM O gt 4J O 40 i 3 r+ k C pound JS
CO pound
^^ s -bullgt cmdash on poundZ VO CTI trx 4J 4J 4J
) bull bull bull Q Q Q Q4J 3shyc O-JJ CTgt OJ OJ Q-IJ inco on CO CO CO o co CM oj on co CM oj on co CM on
Q Q QON^ Q bullH Q^
rH rH 4J rH
O bullraquo L Z bull CO CO CO
i gtgt rH oj on gt tgtshyCM ^ cO^-s CO ~ CO
CO CO J X fc^_ bull^gt bullgtgt bull gt gtgt bull gt CO
j_ jJ O pound- Jj -P O Li deg =fObullH co on f- ^ 3bullH CO CO O in 3bullH CO
g^ -^2
poundsect HO
eis
mic
3 CO in in in in in in co o n co o n
o -^ r oj in O rHCO CO rH bullrH bull rH =T OrH bull rH OJ f-CO 4J bull- CO 4J rH O0) J-)
gt CM gt CM gt CM 4J
CO N_^ m^
bull OJ
t t poundshyCO CO CO CO rH J3 gt r-t oj on gt r-i oj on gt gt r n o j o n
lto co lto CO T bull ii-4 laquomdash bullmdashH
bullo CO L L 0)
CM CO cc
21
N
545-594
seepage observation
hole West Landfill
0NE I47-509
Area
Weir 45
i487-531
0 EC Al3-467
Legend bullmdash landfill limit -bull---excavation limit r-s stream
copy WNWNEECSESCSEN monitoring well locations
= = = unimproved road
Weir location and elevation
feet
Fig 9 Weir Locations and Wate r Level Ranges
22
JT NO
S shy S
O
bull ry m
oa
NO
(M raquo 1 03 or NO m
JT O O raquo
O NO 03 (j
PW tn in ^4 fraquo
m CN) f O O (M Oj
mdashraquo 3 M
s cshy -raquoraquo
o in in ^
rjO
laquobull NO ON
o bull-lt ^
H fy (NJ
tjgt
1 4 03 O
o
o
03 CM
in0
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7 raquo
9gt
IM i iev NO
i in
i ru
i 0 rsi -or^
sO NO
CO O
03 raquo
1 O3
pound o ro CNJ
03
tn B OJ
o 03
m oi
NO
(M
r
(M
CO i M 03
m N ltn ~+ ltM -
QJrH
O M O ^ ^r-
oo m
8 a
m
^ NO
8 fNl
rshy03n
m - in
o laquoO
bull3 as m o 03 03 4
i O
i ^
shy
O
ltM bull^
ON f tn H 1 4 raquo4 i-4 H P-t
^^ lt-l
r-laquo
^ 1 1 1 1
pound raquoraquo O)t o gtz
bull bull ltbull
lt2
1 pound OJ
3 oi g bull
pound
1 pound laquolt bull
3 bull o a
pound
5 laquo15
f bull 3 Jl s
5bull 1 5
23
A field study to determine the infiltration capacity of a
section of tne landfill topcover was conaucted A modified version
of a double ring infiltrometer was used to study infiltration rates
(4) The cylinder diameters useo in this study were 8 inches and 18
inches A constant head of 6 in was maintained in the
infiltrometer and rates of infiltration were determined Tnese
results and an analysis of surface infiltration into the landfill
are included in tne analysis and discussion section
Specific conductance levels in the monitoring wells in the
streams bordering the landfill and at observation holes near the
landfill were measured (Fig 10) This is a good indication of the
mineralization of water (39) Specific conductances were measured
intermittently over the ten month period to develop a picture of the
extent and degree of contamination in the wells (Fig 11 Taole4j
and in the surface contamination monitoring locations (Fig 11
Table 5) A comparative standardization of the Beckman (short and
long probes) and YSI specific conductances is in Appendix C
A surface electrical sounding using the Schlumberger array was
conducted adjacent to Rose Hill Road at the R-l location (Fig 12)
in an attempt to delineate the vertical extent of the contamination
zone Well W was used as a centerpoint and a reference for
water-table depth pore water conductivity and depth to bedrock A
Schlumberger array electrical resistivity sounding was also
conducted in an uncontaminated area at tne R-2 location (Fig 12) to
provide a comparison background interpretation A seismic
refraction survey N-4 was conducted at the same location (Fig 8J to
24
N
excavat ion
Seepage West observat ion Landfill hole
Area
Stream 1 Seasonal observation 0 EC
hole
East Stream2
Legend sw Weir landfill limit j--1--^ excavation limit
copyWNWNEECSESC monitoring well locations
== unimproved road
feet
Fig 10 Surface Contamination Monitoring Locations
25
8000T
7000
O bull U) W6000
Legend
0 sc A NE O W
A SE O N W
a EC
1 O N D J F M M
Time months Flg11 Flucuatlon In Specific Conductance in Wells
26
Table 4 Specific Conductances in Wells (pmhoscm at 25degC)
West East Landfill Landfill
Date NW NE EG SE W SC N E S
81581 851 938 236 2356
102981 171 3268
11381 3268
111081 304 988 1100 258 3800
111481 426 2736 1216 186 4560
111781 304 3610 433 389 4560
121981 380 1406 129 103 380
1982 160 152
31582 274 760 1064 61 334 8000+ 182 53 84
52182 450 1500 1125 112 712 8000+ 175 255 150
52282 425 1320 1200 110 850 180 320 170
27
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28
excavation
West Landfill
Area
Legend bullmdash landfill limit -bullbull--bullexcavation limit r~~s stream
copy WNWNEECSESCSEN monitoring well locations
= == unimproved road
electrical resistivity sounding
feet Fig12 Electrical Resistivity Sounding Location
L
29
allow estimates of depth to water table and bedrocic to be made
Soundings were carried out to 500 foot electrode spacings to insure
that hredrock was penetrated and to facilitate interpretation These
results and a discussion of the soundings interpretation are
included in the analysis and discussion section Schlumoerger
resistivity soundings were made using a Soiltest R-bO unit
30
Model Development
The USGS Iterative Digital Model for Aauifer Evaluation was
usea to develop steady state flow models of the study area (43) A
flow chart of the computer model and a brief explanation of the
subroutines usea is presented in Appendix D The stream locations
elevations and aauiferlandfil1 geometry and hydraulic properties
were input to the model to compute head values at each 200 foot
grid spacing node (Fig 13) The input data which is for the
existing excavation and landfill conditon is listed in Appendix E
The head values that are computed at each grid space are in turn
loaded into the CalComp plotting routine (44) where a grid spacing
is setup with the computed head values at each node The contouring
program linearly interpolates between these head values and
generates a contour map The computer simulated ground-water
contour map for the excavation and landfill is presented in Fig
14
The streams in the model generally serve as controlling boundary
conditions When using computer simulated geohydrologic models of
an area choosing the boundary conditions for the model that are the
same as prevailing conditions in the field is a critical step in
model development Extending the models boundaries to areas in the
field that have a minimum influx of ground-water across them
simplifies the proolem of calculating fluxes from outside the model
area The eastern boundary is bordered by glacial till which has a
low hydraulic conductivity estimated to be 67 ftday(2) This
contrasts to the high hydraulic conductivity of glacial outwash that
makes up the model area of approximately 107 ftday(3036j
31 N
o 9
bullO O
32
33
The Saugatucket River serves as the controlling boundary on the
east A small drainage area directly to the east of it provides a
minimal influx
Beyond the moaels northern boundary the glacial outwash valley
extends to the base of a till covered h i l l on the western half ana
on the eastern side extends along the Saugatucket stream Due to
the relatively large drainage area that lies upgradient from the
northern boundary a recharge flux eduivalent to 10 inyr over the
drainage area on the till hill and outwash area north of the model
area was input as underflow (Fig Ib) Part of this was input at
each northern boundary node Till has a lower infiltration capacity
than outwash so more of the precipitation w i l l be transmitted as
overland runoff resulting in a lower ground-water baseflow The 10
inyr of recharge that results in a ground-water inflow from the
combined till and outwash region represents an estimate that is
smaller than the 14 inyr recharge for glacial outwash areas in
Rhode Island (25)
The glacial outwash valley extends beyond the western boundary
No significant ground-water recharge flux was estimated at this
boundary A relatively low ground-water gradient exists to the west
of this which does not provide a significant flux across this
boundary Tne southern boundary is basically the outflow region for
the area and therefore would not reauire any ground-water flux into
the moael area across this boundary This boundary was set south of
the point that the streams in the model merge together Therefore
the streams which lie to the north of it are the controlling
34
scale 124000
Fig 15 Northern Drainage Area
35
boundary conditions The flux out of the downgradient outflow
region approximately eauals the influx from precipitation recharge
and boundary influxes
When tne stream configuration in the moael area are reviewed it
can be seen that they comprise a large portion of the boundary
area The screams can act as sources or sinks for water in the
model thus providing to and removing water from the aquifer The
leakance option was used in the model which provides for a confining
bed and aouifer area beneath the stream to be input
The leakance is defined as the hydraulic conductance of the
streambed divided by the streambed thickness which in this case is
taken as 1 foot The leakance value at each streambed node
restricts the flow between the aduifer and the stream The
streambed hydraulic conductivity is typically 01 the value of tne
hydraulic conductivity of the aduifer (717) The value 107
ftday was used for a streambed conductivity based on a value of
107 ftday for the aquifer The aduifer and stream hydraulic
inputoutput exchange at eacn node is calculated by initially
finding the difference between the initial field stream head
elevations and the computed head elevation values at the
corresponding nodes This head value is then multiplied by the
(Leakance value at each node) x (stream area of each node)
Therefore if the aduifer head was lower than the stream head the
stream would act as a source of water for the aquifer and vice
versa
36
Tne leaxance input at each stream node is the ratio of the
actual field streambed area in each node to the area of each node
which is 200 ft x 200 ft = 4 x 104 ft2 The west
excavations stream width is approximately 3 ft central 4 ft and
east 5 ft Therefore if tne west stream traverses the node
directly without meandering it presents a leakance of 3 ft x 200
ft4 x 104 ft = 015 Leakance and streamhead values were
input at each node to set up the stream flow parameters in the
models
A recharge value of 14 inyr over the entire area was input at
each node This represents a value of precipitation that is
transmuted into tne ground-water rather than being directly
evaporated evapotranspired through plants or overland flow
runoff The precipitation recharge flow from the stream into the
aauifer and boundary fluxes provide the model witn input flow
parameters
From analyzing the available information it was determined that
the study area lies within a glacial outwash area with a relatively
shallow bedrock The seismic survey around the landfill generally
indicates a depth to bedrock below the land surface of approximately
29-43 ft with corresponding saturated thicknesses of 19-33 ft as
seen in Table 2 This agrees with borings from tne USGS groundwater
map in the stuuy area (18j The seismic survey was run at a low
water table condition which was several feet below the high water
table level (Fig 9)
37
High water-table saturated thicknesses were used to develop
model parameters For the purpose of this model study the saturated
thickness was set at 30 ft except in the vicinity of well W where
there is a bedrock high (Fig 8) At this location a high water
table saturateo tnicxness of 8 ft was estimated In tne vicinity
the seismic survey was conducted the bedrock elevation at this
location is the highest and the saturated thickness the least Tnis
can be seen by an east-west cross section of tne landfill (Fig 16
The boring log for well W indicates a sand trace gravel outwash
material (Appendix B) Boring logs at the eastern landfill area N
and E indicate similar material On this basis the hydraulic
conductivity was estimated at 107 ftday (3036) Witn the
exception of the landfill and the bedrock hign areas the
transmissivity values were set at 107 ftday x 30 ft = 3210
fto day From the literature the hydraulic conductivity of the
landfill material was estimated at I ftday (19) The
transmissivity of the landfill material in tne nortnern section was
estimatea at 1 ftday x 30 ft = 30 ft^day or approximately two
orders of magnitude lower than the outwash In tne landfills
southern section the original excavation was not as deep as in the
northern parts The landfill material was estimated to makeup only
one half tne saturated depth the remainder being the original
glacial outwash material (Fig 17) Therefore the transmissivity
at the southern end was estimated at 15 ft x 107 ftday + lb ft x
1 ftday = 1620 ft^day These values were graded into the 30
ft^day values at the landfills northern halfway point These
38
were input as transmissivity values to the model at their respective
locations This model did not use the water taole option so
water-table fluctuations did not affect the transmissivities
39
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Model Calibration
A simulation was run using the initial estimates of stream
parameters aquifer and landfill hydraulic conductivities
transmissivities boundary and recharge conditions to approximate
water taole conditions in tne fiela Initially the existing
condition of the excavation area to tne west of Rose Hill Road and
the landfill to tne east were modeled in order to calibrate the
model to current field conditions as shown on Fig 4 The simulated
well values (Fig 14) fall within tne range of field values (Fig
9) The resulting contours also provide an approximate matcn This
can be seen by comparing Fig 4 with Fig 14 An additional check
was to match the flow loss and gain in the streams between tne weirs
in the central stream which w i l l be discussed later The
simulated flow value from the excavation drainage stream is the same
as that measured at the SW weir location Having calibrated the
model by approximately matching well water levels nead contours
and scream flow values different field conditions and possible
remedial measures can be simulated
When the model grid was laid out over the study area as viewed on
Fig 13 the stream configuration rarely traversed the grid nodes near
their central axis When the stream locations were input to the
computer the information was documented as crossing the central axis
of the grid nodes The result of this is a slight aberration when
the actual stream configuration is laid over the computer graphics
head contour output The streams dont always cross the groundshy
water contour at the logical location Rather than modifying the
actual stream configuration to adjust then to the computer output
their actual locations are presented
42
Simulations
i The primary focus of the computer modeling is to analyze flow
patterns under changing conaitions in the near vicinity of tne raquo
landfill The study areas overall flow patterns as they exist
today are first presented in order to realize the lateral east-west
head contour lines between the stream that directly borders the
landfill on the east side and the SaugatucKet stream (Fig 14)
This indicates a general southerly flow direction in that area As
different conditions are modeled these contours generally maintain
their east-west orientation In order to facilitate interpretation
of flow patterns in the near vicinity of the landfill flow patterns
to the west of the stream that borders the east side of the landfill
r are presented in the subseauent models
L- Natural Conditions
The results of modeling the original natural conditions are
shown in Fig 18 The excavation and stream to tne west of Rose
Hill Road and tne landfill did not exist in this simulation The
southwestern boundary consists of a drainage stream that was
delineated using an aerial photograph and stream elevations were set
using the topographical map The USGS ground-water map (18) was
used to estimate head values between the west excavation and north
streams These were input to the model as constant heads on the
models western boundary The resulting simulation generally matches
the southeasterly flow direction that is indicated on the
ground-water map (Fig 5)
A3
Legend
x-^- stream 400 = = = unimproved road
I f ee t
Fig 18 Natural Conditions
44
Excavation Without Landfill
The condition of the excavation to the west of Rose Hill Road
with its resultant drainage stream without the landfill was modeled
next (Fig 19) The extent of the excavation ana the location of
the new drainage stream were delineated using the aerial
photograph The west stream elevations were sited in the field and
used in the model The concept of a confining streamoed layer was
excluded in tne excavation drainage stream under the concept tnat no
significant organic layer had been built up within the 25 year
period that the excavation had been initiated Head values between
the west and north stream boundaries were interpolated and input as
constant head values on the northwestern boundary The west
excavation drainage stream creates a condition that alters the
natural ground-water flow patterns by creating a more southerly flow
condition the drainage stream providing a more immediate surface
outflow in that area
Landfill Without Excavation
The hypothetical case of a landfill without the excavation was
modeled next (Fig 20) The low hydraulic conductivity zone of the
landfill changes the natural flow conditions and creates noticeable
mounding This is evidenced by the decreased spacing of the head
contour lines and deviation from the lateral contour lines of the
natural conditions and higher head values (Fig 21)
45
Legend
excava t i on s t ream
400 unimproved road
f e e t
Fig19 Excavat ion without Landfill
46
Legend
landfill limit
bull - s t ream 400 copy WNWNEECSESC
monitoring well locations f ee t bullbull-bull=bull unimproved road
Fig 20 Landfill without Excavation
1
oin CM
bull
m u
0)rf
oO
bullo 9
bullo 9
o rf o o CO 1
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47
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48
Landfill ana Excavation
The condition of tne existing landfill and the excavation with
the dam is the next condition modeled (Fig 22) The ground-water
elevations used to calibrate tne model correspond to an actual high
water table condition Between the NVJ and pound weir a streamflow loss
of approximately 102 gpm occurs aoout 60 percent of this flow is
lost at the dam site which maintains a head of b-6 feet over an area
of approximately 1800 feet^ This approximates a field value of
1144 gpm influent to the aduifer between the NW and E weir on ]2
December 1981 (Table 3) From the E weir to the SE weir a net
increase in flow occurred of 74 gpm which corresponds to field
increase of b62 gpm
The surface runoff from tne landfill flows primarily toward tne
eastern side of the landfill Increases in water-table elevations
on the eastern side after heavy rains such as the 11 November 1981
storm indicates that this runoff increases outflow gradients to the
stream and therefore increases streamflow Surface runoff input is
not modeled which explains in part why field stream inflow values
are slightly higher than model predictions especially for periods
after a storm has occurred The flow from the SW weir located at
the southern end of the excavation represents drainage outflows from
that area The net flow calculated in the model was 140 gpm
which approximates field conditions of 1642 gpm on
December 9 1981
49
d f l f reg N E
shy
Legend
landfill limit -bullgt-bullgt- excavation ^-N_X- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road
-40mdash approximate groundwater contour
400
feet
Fig 22 Landfill and Excavation with Dam
50
The modeled flow patterns suggest how the various contamination
zones around the landfill have developed to their present state
They indicate a flow to both the southeast and southwest on their
respective sides of the groundwater divide Evidence of a
southwesterly contaminant flow is presented when the continued high
specific conductance contaminant level in tne observation seepage
hole is realized (Table 5 ) In addition the specific conductance
increase in the west excavation stream is evidence of an influent
contamination flow
Contamination flow to the eastern and southeastern side of the
landfill is obvious High specific conductance levels in the wells
on the eastern side (Table 4 ) a specific conductance increase
between the E and SE weirs (Table 5 ) and contamination in the NE
domestic supply well (Fig 3) present conclusive evidence of
contamination to the eastern side of the landfill
An anamalous condition that exists is a domestic supply well
located approximately 300 feet due south of the landfill remains
uncontaminated (Fig 3) Flow patterns indicate that contamination
would be transported from the landfill south to this area
(Fig 14) One explanation is that a pocket of clay at the southern
end of the landfill area was discovered in the original excavation
for the landfill (lt6) This evidently prevents leachate from
reaching this wells radius of influence
51
Summer Conaitlon
As described earlier during dry months of the year the stream
that normally borders the northern and eastern side of the lanafill
may dry up as far as a point southeast of the E well Tnis
condition existed from the 15 August 1981 to the 27 October 1981
period when streamflow commenced in the northern part of the stream
yet did not overflow the north dam until 17 November 1981 This
created the present day continuous flow condition throughout the
stream These summer conditions were modeled by removing the stream
above the aforementioned location while other conditions remained
the same (Fig 23) Summer condition well water levels listed in the
model generally match field low water table conditions (Fig 9)
Because there is no stream upgradient from the landfill to provide a
stream head and infiltration through the streambed groundwater
runoff from the area north of the lanafill is the controlling flow
input In these moaels an average recharge of 14 inyr was used
which represents a yearly average The summer recnarge conditions
are prooably lower given the effects of decreased rainfall and
increased evapotranspiration during the summer months A domestic
supply well whicn exists northeast of the landfill (Fig 3) nas a
greater potential to be contaminated from the lanafill at tnis time
than when the stream is flowing Flow patterns from the landfill
are such that during an upper stream no-flow condition groundwater
flow patterns are more in an easterly direction than in a
southeasterly direction The stream would act as a source of
infiltrated water upgradient from tne landfill and provide a
52
I ^N gt i I i j i -r- -bull- bullr -T- t- -r- i- TJ JV
bullbullT laquo ^ O - laquo bdquo xi cshy
H r^~ I -~- --^ X- = mdash x^ N
^--^ A bull O^NW -v - gt-bull Ni i I _____mdash - bull laquo l - mdashmdash 1 deg I ^ltv I C
I reg NE A
Js bull vbull A ~ - v T gt- ^ ix - N
-5Z- | N TfS lV I -bull bull iA i gt gt I ^ bullr-Ky L bull 1 _- copy]wgt-- - bull- mdash - - shy
= r Y ~mdash ltmdashA A
^^-lt A _ - - - - bull Hmdash - reg EC x ^-mdash mdash I ---mdash_mdash -t-V-^N - y
I- -bull - r x i X
V ^ 7 I -v (^~~^^r ^^^
sc Emdash-bull vV JI - - - ~ r )N y- -
X - bull r bulllt
^bull^ y y Jlaquo^ - -lt shy
T s^ lt^ ^ +^-b (
X
Legend
landfill limit j-j-bullraquobull excavat ion gt^ -x- s t ream
reg WNWNEECSESC monitoring well locat ions
= == unimproved road fee t
Fig 23 Summer Condition
400
53
constant head across tne northern section of the landfill This
would tend to orient the flow in a more southerly aowngradient
direction In addition the stream which flows adjacent to the
northeastern well could provide a source of infiltrated clean water
to it which would minimize the possible contamination from landfill
leachate
Without Dam
During tne spring scream flow condition the dam failure which
occurred between the 15 March 1982 ana 9 April 1982 monitoring
periods decreased flow to the aauifer and landfill This eliminated
the 5-6 foot head difference over a 19000 ft^ area which had
created a larger area and elevation head for infiltration to occur
The condition without the dam was modeled by reducing the area
encompassed by the dam to a 4 foot wide stream channel thus
reducing the leakance value at that node (Fig 24) The flow change
from the stream to the aduifer between the NW weir and E weir
reduced the model flow loss to 50 gpm Tnis corresponds to the 9
April 1982 monitoring period which indicates a 30 gpm loss
As compared to the previous flow loss in the upper stream
sections to the aauifer the 21 April 1982 and 22 May 1982
measurements between the NW and E weirs indicate a flow gain The
streamflow conditions have changed from an influent
stream-to-aauifer condition to an effluent aduifer-to-stream
condition that increases flow downstream
54
Legend
landfill limit j--i--i- excava t ion x-gtmdash^- stream 400
copy WNWNEECSESC monitoring well locations
= == unimproved road f e e t
Fig 24 Landfill and Excavation without Dam
55
Analysis and Discussion
In order to fully understand flow patterns and Quantify leachate
outflows at the landfill it is necessary to arrive at an estimate
of flow inputs from precipitation ana upgradient sources In the
following analysis it will be demonstrated that the rainfall input
to the landfill is the factor which controls leachate generation A
calculation using the H inyr recharge over the area of the
landfill was made to estimate the leachate outflow due to rainfall
infiltration An estimated 134 gpm is generated from the entire
landfill area Simulation of the existing conditions (Fig 24)
indicates a groundwater divide in the landfill is located
approximately at the western third Therefore approximately 23 of
the generated leachate flows to the eastern side of the landfill or
9 gpm The effect of the flow input from the upgradient stream is
evident when tne summer condition witnout the stream is viewed
(Fig 23) Without the stream to infiltrate the landfill and the
recharge and northern boundary condition as the flow inputs the
head at the northern end of the landfill drops about 5 feet from its
previous value A flow pattern from the north central part of the
landfill to the eastern side indicates a 12 feet head difference
with recharge - but with the upgradient stream a 16 foot head
difference occurs Considering the transmissivity change the
stream would increase the leacnate outflow from the landfill
approximately 43 under a low water table stream influent condition
to the aauifer This would increase leachate outflow to the east
side to approximately 129 gpm This value approximates the
56
outflow at the SE weir location during the summer monitoring period
when the upper stream was not flowing (Table 3) The outflow from
the western third of the landfill whicn lies to the west of the
ground-water divide would be approximately 63 gpm
Realizing the importance of infiltration to tne landfill as a
major influence on the generation of leachate an analysis of this
w i ll be discussed An estimate of infiltration was made using the
precipitation recora for October ana November (Appendix A) During
this time period a minimum of direct evaporation ana
evapotranspiration occured and the grouna is not yet frozen The
top cover over the lanafill is generally 05 ft to 2 ft of local
sandy soil and subsoil availability determined what was used The
top of the landfill is at an elevation of 92 ft as compared to the
ground surface at well W which is at an elevation of 76 ft
(Fig 25) This compares to the well W water level which is at an
elevation of approximately 52 ft This creates a long path for
infiltration through the unsaturated zone The topcover generally
slopes eastwara at a grade of 2-5 The west side maintains a
relatively steep slope of 10-15 ft drop within 50 ft ana the north
and eastern slopes have a more gentle slope of approximately 10 ft
within 100 ft distance An unlined surface arainage swale channels
surface runoff from the northern section of the landfill past the
NE well to the eastern side ana low area in the vicinity of the E
well This has a drainage swale to an area near the stream but
doesnt directly connect to tne stream A poorly graaed drainage
swale exists on the landfills left side The landfill material has
57
excavation
seepage observation ^
hole
Legend bullmdash landfill limit -^--excavation limit r^s- stream
copy WNWNEECSeSCSEN monitoring well locations
--- unimproved road O location of amp Inf i l t rometers O
feet
Fig 25 Infi ltrometer Locat ion and Drainage Feature
58
been placed in 10-12 ft cells and covered with 1 ft of soil at the
end of each day The material has settled differentially creating
areas for depression storage
An estimate of the percentage of precipitation that infiltrates
the landfill was made from precipitation records recorded well
elevations and an estimated specific yield for the landfill
material The volume of water that infiltrated should eaual tne
specific yield multiplied by the well water level rise Several
recharge periods were studied using this relationship Once the
percentage of precipitation that has infiltrated is determined the
percentage that is translated into runoff is simply the remaining
percentage if evaporation is neglected
From the literature for a slightly inclined slope of 2-5
typical runoff coefficients range from 10-20 in either sandy or
heavy soil (16) The landfill cover is generally sloping to the
east which creates a long path (approximately 400 ft) before the
runoff reaches the steeper slope on the eastern side of the landfill
of 15-20 The long drainage distance creates a greater time for
rainfall to infiltrate Another consideration is the actual
capacity of the soil to conauct water into the soil which was tested
in the field using double ring infiltrometers An average initial
percolation of 8 mmhr the first hour and a subseauent rate of b
mmhr occurred (Fig 26) The 8 mmhr rate compares well with
other sandy soil infiltration rates (14) Therefore if the
intensity of the rainfall exceeded a 5 mmhr rate for several hours
59
CO + 09 o
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CO
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o DC
CO
CD CM
ogt CO N- to -4 CO CM
jq tuu i U O | raquo B J J | | J U |
60
on a poorly drained surface the additional rainfall would be
translated into runoff because the soils infiltration capacity had
been exceeded
The initial 8 mmhr infiltration rate was due to the pore spaces
in the sandy soil being filled and the subsequent 5 mmhr rate was
percolation into the low permeability landfill material The tests
were conducted in November assuming a minimal evapotranspiration
and the field capacity of the sandy soil had been maintainea
The W well was used as representative of the water elevation
changes in the landfill because it is directly adjacent to the
landfill 900 ft distant from the upgradient stream This minimizes
the effect of infiltration from the stream and maintains a high
contaminant level During periods of high runoff conditions excess
surface water ponded in a poorly graded drainage swale on the west
side and directly adjacent to the landfill This influenced the W
well at a time the contamination level dropped (Fig 11) Before
this occurence in mid-December the rise of the W well closely
matches that of the SC well and a background well SK6 which is
located outside the study area (Fig 7) Therefore it was analyzed
as a valia indication of the water level rise during the mid-October
to mid-December period The monitoring of the SC well was
intermittent due to inaccessaoility because of 10 ft extensions
being placed on the well as the refuse was being filled in arouna it
61
A high rainfall period from 14 November 1981 to 1 December 1981
was chosen for the initial study period The effects of
evapotranspiration were neglected due to the cool temperatures
experienced at this time Therefore it was assumed that the field
capacity haa been reachea and tnat any additional input to tne
unsaturated zone would result in direct percolation to tne saturated
zone During the time period 14 November 1981 to 22 November 1981
029 ft of rainfall fell and the well W rose from 488 ft to 493
ft - a 05 ft increase During the next 8 day period there was no
precipitation yet the W well continued to rise to 4972 - a 042 ft
increase The slow percolation of water through the landfill
material would account for the latent rise in the well water level
From previous reports a specific yield for refuse was estimated to
be 028 (1920) This value is dependent on the original compaction
of tne material age and resulting consolidation
During the 14 November 1981 to 1 December 1981 period 029 ft
of rain fell and the well increased 092 ft The following
relationship is used to evaluate the infiltration value and runoff
I = (Sy) h
Sy = specific yield
h = well rise
I = volume infiltrated
I = (028) (092 ft) = 0261 ft
62
The difference between the precipitation and the infiltration is
the runoff (assuming no evapotranspiration) Therefore 029 - 026 =
003 and furthermore 003029 - 13 runoff This corresponds in
the literature to a typical runoff coefficient for an inclined
surface of 2-5
Analyzing a longer precipitation period from 18 October 1981 to
1 December 1981 a net precipitation of 043 ft (accounts for
evaporation) occurred less 10 for runoff or 039 ft infiltrated
This results in a 139 ft elevation increase The well water level
actually increased 132 ft shy only a 5 deviation from the
calculated
From tnis investigation it is seen that a large proportion of
the precipitation has the potential to be transmitted into the
landfills saturated zone Exceptions are wnen heavy precipitation
periods exceed the soil percolation capacity frozen ground prevents
infiltration and direct evaporation and evapotranspiration recycles
the ponded surface water and infiltrated soil moisture back to the
atmosphere In retrospect water temperatures within the monitoring
wells could have been measured to indicate thermal effects from the
landfill on ground-water temperature Ground-water temperatures
were assumed to be 50deg F (9)
63
Specific conductance measurements serve as an indication of
contamination levels These measurements are used to trace leachate
movement which represents ground-water flow patterns Factors which
must be considered when monitoring pollutants are the attenuation of
the leachate contaminants which occurs both in the zone of aeration
and the saturated zone The former is a more complete process
Dilution dispersion and cation exchange are the primary factors
involved in decreasing leachate concentration in the saturated
zone The glacial outwash materials of southern Rhode Island do not
have a cation exchange capacity or a high buffering capacity so
attenuation is simply by dilution and dispersion (22)
The NW well consistently exhibits relatively low specific
conductance levels even though it is in landfill material It is
situated in a drainage swale and ground water elevations range from
543 to 5944 This is several feet below the upgradient stream
elevation of 64 feet which is less than 400 feet away The bottom
of the wellpoint is at an elevation of 5312 feet well into the
landfill material Infiltration from the stream to the landfill has
occurred at this location
The W well is situated on a bedrock high adjacent to the
landfill approximately 900 feet from the upgradient stream and its
water level is higher in elevation than the excavated pit (West
Observation Hole) which is 300 feet directly west The W well
maintains a contaminated level A poorly graded drainage swale to
the west of the landfill provides areas for extensive ponding and
infiltration to occur which explains the drop in conductance after
a high runoff period
64
The SC well is located in landfill material and has a
conductance of over 8000 umhos This indicates that leachate is
undiluted The oottom of the wellpoint is at an elevation of 389
feet which is situated in the landfill material
High specific conductance measurements in the west observation
hole and well W and their relative elevations indicate a
west-southwesterly flow direction from the landfill Infiltration
recharge and leakance from the stream into the landfill provides the
necessary elevation to cause outflow in this direction
Contamination from the landfill to the surrounding streams is
evident (Table 4) During the period 15 August 1981 to 27 Octooer
1981 there was no flow in the stream that Borders the northern and
eastern side of the landfill until a point just south of the E well
was reached High specific conductance levels in the EC and NE
wells were recorded (1000 jjmnos) At a point directly east of well
EC a pool of water existed that was relatively uncontaminated which
is designated as the East Stream] location (Fig 10) At a point
just south of that (East Stream^ polluted water in the streambed
was flowing at a low rate This was measured at the SE weir
location and which had a high conductance also Flowrates varied
between 6 and 23 gpm and specific conductances were over 350
pmhos This low water table condition flowrate is the baseflow from
the eastern side of the landfill and indicates a southeasterly flow
direction from it
Streamflow commenced in tne northern part of the stream 21
October 1931 and the north dam oegan to f i l l Stream specific
65
conductances were low indicating a clean water source Tnis
continued until 17 November 1981 when the dam overflowed ana flow
throughout the east stream began A weir was placed at the Rose
Hill Road NW location and was compared to flowrates at the SE
location Flowrates decreased and specific conductances increased
between these two locations
To further investigate the condition of a lower flowrate
downstream than upstream an intermediate weir was placed at the E
weir location (Fig 9) This snowed tnat the stream from the M
weir to the E weir was losing water to the aauifer (influent
condition) and gaining water at the SE weir (effluent condition)
The condition of a net loss of water between the NW and SE weirs
remained until 19 December 1981 when a snowmelt rain condition
caused increased surface runoff and a net increase in flow at the SE
location Upon analyzing the March and April 1982 streamflow
conditions the expected case of a net ground-water pickup from the
E to SE weir continued The explanation for tne initial net loss of
ground-water is the fact that the leakance from the upstream section
was being discharged into aauifer storage to raise the ground-water
table to an eduilibrium level Upon reaching a high recharge
equilibrium steady state condition any additional input will
eventually be transmitted as baseflow out of the landfill and a
downstream net pickup will occur A hign water table condition
prevailed during the January through May period maintaining this
condition In April the north dam broke through reducing the head
in that area by 4-6 feet The 9 April 1982 monitoring revealed that
66
an influent condition remained between the NW and E weirs but at a
reduced rate The 21 April lower stream flow condition shows a
small pickup of water between the NW and E weirs indicating the nigh
water table and low stream flow conaitions combined with the absence
of the dam had changed the conditions to an effluent condition
This was evident in the May monitoring period
Evidence of contamination on both the western and eastern sides
of the landfill supports the existence of a ground-water divide in
the landfill The west stream which drains the excavated area to
the west of Rose Hill Road shows contamination pickup between its
northern section and the SW weir The W well and ooservation hole
indicate high contamination levels which reinforces the concept of a
contaminant outflow to tne west excavation stream
As shown previously flow towara the eastern side of the
landfill is evident from the nign specific conductances and specific
conductances increases in the stream This is especially evident
during low flow conditions when the stream starts at a point to the
east of the landfill and flows with high specific conductance levels
From the literature a relationship between specific conductance
and dissolved solids exists the dissolved solids (mg1) are
approximately equal to the specific conductance times a factor
ranging between 55 and 09 (39) in this case it is taken as
065 (41) The dissolved solids increase coupled with the stream
flow increases provides a basis of calculating the dissolved solids
outflow to tne stream This calculation method was used in a
previous study (26)
67
The relationship
=Cinout Coutflow Qoutflow - Cupstream Qupstream Qinput
where the numerator is the streamflow pickup and the C- and
Q-jnput is the concentration and flow input from the ground-water
This can be used to estimate dilution level outflows from the
landfill Initially this is used for the ambient ground-water
pickup between the E weir and the SE weir This entire flow doesnt
come from tne lanafill but much of it is conaucted in the high
transmissivity area between the lanafill and stream from upstream
leaxage ana surficial recharge Tnis is evident when this section
of the flow pattern is analyzed on Fig 22 Therefore the landfill
outflow is mixed with tne ambient groundwater flow which dilutes the
landfill leachate before it enters the stream To illustrate-this
concept a calculation using the 9 December 1981 monitoring is used
At this time a flow of 672 gpm occurred at the SE weir with a
specific conductance increase of 7 ymhos between the E and SE
weirs The dissolved solids increase would be approximately 795
Today in tne stream
Where
Co = 90 jumho at SE weir
Qo = 672 gpm at SE weir
Cus = 83 jumho at E weir
Qus = 606 gpm at E weir
Qinput = 66 gpm gain
Cinput = 154 jumho
68
The 154 jumho value represents the contaminant level in the
ground-water adjacent to the landfill
This relationship is applied to approximate the concentration
level dilution in the ambient ground-water between the landfill and
stream The aforementioned relationsnip is in turn applied to the
landfill outflow into the ambient ground-water flow adjacent to the
landfill The ground-water receives landfill leachate dilutes it
and then transmits it to the stream The previously calculated
value of 129 gpm was used as the outflow from the landfill
Co 154 jumho flows into stream
Qo = 67 gpm flow into stream
Cus = 83 jumho background level
Qus = 67 gpm - 129 gpm = 541 gpm
Qinput = 129 gpm from landfill
Cinput = 451 jumhos
Approximately tne same contaminant levels from the landfill (tbl
umho) are arrived at as existed in the summer streamflow conditions
when the upgradient ground-water flow adjacent to the landfill was
at a minimum
In addition to using specific conductance to define
contamination zones electrical resistivity can be used to indicate
contaminated areas The measured earth resistivity is inversely
proportional to the conductivity of ground-water Water containing
contaminants with high ionic concentrations are more electrically
conductive and will have lower resistivity values than surrounding
natural ground water Therefore resistivity methods can be used to
69
delineate plumes of contaminated ground-water that have hign
specific conductances This has been demonstrated by several
investigations (11122328374045)
In this study a Schlumberger vertical electrical sounding R-l
was made in an area of known contamination at the W well (Fig 12)
Given the geologic constraints provided by the well boring log a 4
layer computer model was used to match field survey values A
Schlumberger sounding R-2 in an uncontaminated area north of the
landfill in the same geologic setting was used to provide a
comparison background sounding (Fig 12) A seismic survey N-4 was
made to obtain water table depth and depth to bedrock as input
parameters to a four layer resistivity model (Fig 8) Tne results
of the electrical soundings have been tabulated in Table 6 and
plotted in Fig 27 and 28 respectively
The ascending portion of the field Schlumberger curves were
initially matched using a two-layer ascending type master curve to
provide an approximate depth and apparent resistivity of the
overburdened topsoil layer (8) Tne second unsaturated layers
apparent resistivity was determined by using the graphical
interpretation of total transverse resistance The total transverse
resistance is approximately eoual to the peak value of the curve
times the corresponding Ab2 distance it occurred at This in turn
is eaual to the sum of the first two layers apparent resistivity
times their corresponding layer depths
70
bullH
OJ bull bullH 4J CO CM
c ce G bullrH
j-gt ca c c a 3 ltu O L
co CO 0
bullo Q bull laquos c n 3 -U OrH f~ 3 bO ltn y CO O cc CO ^mdashN
QQ bull
bO bOJJ C C Ci_i
O l T i O O O O O O O O O O O O O O O O bullH bullH mdash^ bullo 0 C c3 f| 3 O raquo O CO CQ
CO
rH
CO O
L 4J
^ltU
i- 1 ^n ^b O 4-) bull2 CM bullH C OJ 1 -U bullH CO C L O a ^-^ 0) a
rH c a L CD ltu (1) 3 tlt bO cO I
3 a 0) a Q 4J laquoa e CO 3 (H bO c C O bullH
CO TJ C 3 bull
bull O bO -i-3
0 CO C O3- O G O O O O O O O O O O O O O O O O O O ft rt1 -raquo - t l S^ ft tfigt f I mdash^ K_ l_ raquo mdash I gt fgt I l 1
(1) 0 rH CO CJ JD o^^ CO CO CQH lts
71
Legend
A actual field measurement
-e- interpretat ion
10000 bull
6000 bull 5000
4000-
3000shy
pound2000| ltD
_ r 1000
09
5 600 pound 500 - 400
I 300 a a lt 200
100 10
Fig 27
20 30 4050 100
Distance AB2
Schlumberger Sounding
200
feet
R-1
400 600
72
loooot
6000 5000 4000
3000+
laquo2000 e
r 1000
raquo 600 pound 600 ~ 400
$ 300 a a lt 200
100
Legend
A actual field measurement
-Qmdashinterpretation
10 20 30 40 50 100 200 400 600 Distance AB2 feet
Fig 28 Schlumberger Sounding R-2
73
Formula T = f
Background Sounding (9000)(15) = (3110j (1 7) + gt2(8)
= 16214 n- ft
W Wel l Sounding (b200)(60) = (500) (2) + pound2(28)
= 13250 SL- ft
To determine a resistivityp3 value for the third layer a
graphical interpretation for the longitudinal conductance S was
used(48) This is eaual to the sum of each individual layers depth
divided by their apparent resistivity
Formula S = -r1 +~r-raquobull-ra
Background Sounding 0017 = yyg + ~^
= IbOU - ft
W Well Sounding 0285 raquo -ggg 7^3 J~
= 179 v-ft
These values were input to a program which calculates a
schlumberger sounding curve (47) The theoretical sounding curves
approximately match the field curve as viewed on fig 27 and fig
28 To provide a check on the apparent resistivity of the saturated
layer at the W well the following relationship was applied 1OOOO
= spec-jfic conductance (umhos)
74
At the W well the specific conductance was measured to be 3 00
jmhos at approximately 10degC
Assuming a formation factor of 45 for the glacial outwash (23)
material Archies law is applied to estimate an apparent resistivity
of the third layer (7)
fgt FF x p
A= 45 x 103-n-ft
A= 4G3 JL-ft
This is a reasonable approximation to tne 3i= 179^-ft calculated
analytically from the sounding curve interpretation
75
Remedial Measures
With the analysis of f low patterns and contamination zones
recommendations to minimize the environmental impact of the leachate
can be reviewed The basic technique is to minimize all sources of
water reaching the refuse so that leacnate production is minimized
The oiversion of precipitation by a relatively impermeable cover and
proper channeling of runoff would minimize percolation into landfill
material Caps and seals can be constructed of clays fly ash
soils soil-cement lime stabilized soil memorane liners
bituminous concrete and asphalttar materials (15) Proper
contouring and grading will help minimize infiltration If a soil
cover is used a vegetative cover can be planted which will utilize
some of the infiltrating flow through evapotranspiration losses
during the growing season By minimizing the length of slopes and
providing proper drainage channels tne surface runoff can be
conveyed to a downgradient area outside the recharge zone
Therefore this surface water will not increase leachate production
from the landfill Also by increasing the slope of the cover over
the landfill itself a higher percentage of runoff and lower
infiltration will occur
To minimize upgradient ground-water influx to the landfill an
impermeable subsurface barrier or intercepting trench could be
used Barriers can be made of bentonite slurry-trench cutoff walls
grout curtains or sheet piling cutoff wal ls extending to the bedrocic
or an impervious layer to effectively prevent water passage or
create a head loss that wil l lower the water table In addition an
76
intercepting trench which has a perforated drain at tne lowest part
of the water seepage zone could be used to intercept and divert the
entire flow
These possibilities have been evaluated with the help of the
model to determine workable solutions for this landfill The
primary concern is to eliminate leachate flows to domestic wells
Initially a simulation was run that eliminated recharge over tne
landfill area (Fig 29) This had a considerable effect on the
ground-water flow patterns of the landfill area The mounding that
had previously occurred under normal recharge conditions was
eliminated and a general drop in the water taole within the landfill
of 2-3 ft occurred The effect of eliminating recnarge over the
landfill when the upper stream is running would cause greater
infiltration from the stream as evidenced by only a 2 ft head loss
in the landfills flow conditions This is evident when comparing
Fig 29 with Fig 24 Tnis indicates that this measure would only
marginally reduce the resultant leachate flow from the landfill
material that lies below the water table In another situation
where there is not such a strong potential for upgradient flow this
measure has proven quite effective (6) In this case the landfill
cover consisted of four layers an intermediate sand and gravel
cover immediately above tne regraded waste materials a 4 inch sana
bed designed to protect the overlying membrane a ilO mil flexible
PVC membrane and an 18 inch final cover of sand and gravel
77
Legend
landfill limit -raquo- -^ -raquobull excava t ion x-^x- s t ream
400 copy WNWNEECSESC monitoring well locations
= -= unimproved road fee t
Fig 29 No Recharge over Landfill
78
Controls such as 10-30 mil polyvinyl chloride covers favor the
development of an anaerobic environment which increases waste
decomposition time and would necessitate installation of gas vents
at several locations on the landfill cover Tne integrity of tne
synthetic cap may be further threatened by subsidence which create
differential stresses on liners Settlement would create areas for
ponding and depression storage and eventually necessitate regrading
the landfill surface The landfills south-central area has oeen
filled within the last year and will prooably need to be regraded
due to settlement within the next few years
Another possibility for a liner would be a soil-bentonite
cover A layered cover consisting of natural materials with low
permeabilities such as bentonite clay followed by a layer of highly
permeable material such as sand and finally a layer of topsoil can
be used Due to potential drying out and cracking of the clay liner
a synthetic liner is the preferred method
The most immediate technique is to grade contour and vegetate
the landfill cover which has been done at this site Althougn an
impermeable cover would probaoly reduce the amount of leachate
produced it would not eliminate the upgradient flow and provide
guaranteed protection of wells in the vicinity of the landfills
northwestern section
A slurry trench along the northwestern perimeter of the landfill
would effectively cutoff upgradient infiltration and divert recharge
infiltration in a southeasterly direction thus removing possible
leachate outflows from the radius of influence of the neighooring
79
wells This has been simulated using the computer moael ana flow
patterns as shown in Fig 30 Contour lines are distorted in the
vicinity of the slurry trench due to the 200 ft nodal spacing
Transmissivity values of 1 ftday were input at the slurry
locations to simulate an impermeable barrier Tne surface recharge
at those nodes does not infiltrate the relatively impermeable grid
nodes at the slurry locations and flows to the edge of the noae
thus creating a dramatic head loss within a short spacing To
effectively simulate this a variable grid spacing should be used
with reduced node grid spacing at trench locations to eliminate
distortion The computer simulation shows that the slurry trench
could direct flow in the landfill area in a southeasterly direction
and away from endangered wells In addition it would reduce
upgradient infiltration from the stream into the landfill This
measure would prevent leachate from spreading beyond this carrier to
possibly contaminate neighboring wells
The combination of both the slurry wall and impermeable cover
would be ideal measures to minimize generation of leachate and to
stop its spread to neighboring wells The slurry wall without
recharge over it or the landfill is simulated in Fig 31 This
indicates a lower water table tnan eliminating the recharge to the
landfill The slurry wall has blocked upgradient ground-water flow
at its location to the landfill
80
Legend
landfill limit -laquo- j -laquobull excava t ion ^^- stream
copy WNWNEECSESC monitoring well locations
= = = unimproved road ssi slurry wall
f e e t
Fig 30 Slurry Wall
81
Legend
landfill limit j- j- J- excavat ion x-v^gt- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road s==s slurry wall
400
feet
Fig 31 Slurry Wall without Recharge Over It or Landfill
82
An intercepting drainage trench is considered next If a trench
was excavated to a 30 ft depth in the outwash material extensive
shoring would be required In addition difficulties would arise
when the trench was excavated below the waterline Tne trench would
be sloped to provide drainage and backfilled with a highly pervious
material to intercept and divert leacnate locally a conouit which
is perforated on the top to allow infiltration and unperforated on
its lower perimeter to permit continuous drainage to the collection
treatment center would be installed on the bottom of the graded
trench The difficulties involved in excavating below the water
table ano shoring the sidewalls to permit implacement of a drainage
conduit at a 30 foot depth make this option increasingly infeasible
83
Conclusions and Recommendations
The location of the South Kingstown landfill in permeable sand
and gravel glacial outwash material (107 ftday) combined with the
high hydraulic gradient across the landfill area (20 ft1600 ft)
creates a high potential for ground-water contamination to occur
This is intensified because refuse nas been placed below the water
table The low hydraulic conductivity of the compacted refuse (1
ftday) and the excavated area to the west of Rose Hill Road have
both contributed to modifying the original southeasterly flow
pattern These modifications have created a ground-water divide in
the landfill at approximately the western third section Tnis
results in approximately 13 of the leachate flow from the landfill
or 63 gpm flowing in a southwesterly direction and 23 or 129
gpm flows in a southeasterly direction Infiltration from
precipitation recnarge over the landfill (up to 9Upound) and from tne
upgradient stream during low water-table periods provides tne
necessary influx into the landfill Evidence of contamination is
clearly seen on both the east and west sides of the landfill which
reinforces the previously stated flow patterns
Of the several remedial measures reviewed the contouring and
grading of the landfill topcover and drainage swale provides the
most immediate protection The topcover has been graded mulched
and seeded to provide a low runoff slope generally to the east
The drainage swale on the left side of the landfill has improperly
graded sections which should be corrected Its northern section
could be drained into the northern sections swale and the southern
84
section drained to the southeastern section of the landfill Tne
point of the drainage swale which divides the northern drainage
swale from the southern one should be determined by a field survey
Cost is a major contributing factor when determining which
remedial measure is to be applied to the given situation For the
purpose of this report cost estimates are not presented but rather
the effectiveness and feasibility of the remedial measures are tne
primary considerations As was reviewed and simulated in the
computer models the slurry trench and impermeable cover over the
landfill are two viable options that would effectively provide
protection to the domestic supply wells in tne vicinity The
impermeable cover would eliminate precipitation recharge into tne
landfill yet drop the water table only a few feet due to upgradient
infiltration from the stream This would decrease the hydraulic
gradient thus diminishing the potential for a contaminant outflow to
surrounding wells The supply well of primary concern is one to the
west of Rose Hi l l Road marked well D on Fig 2 If contamination
occurs in this well the most effective measure would be to block
off leachate flow in this direction by installing a bentonite slurry
trench at the location indicated previously This would effectively
prevent leachate flow in the westerly direction and diverts it to a
more southeasterly direction In addition the slurry trench
precludes infiltration flow into the landfill from the upgradient
stream
85
Tnis report has effectively reviewed tne original ana existing
flow conditions and contaminant levels in the vicinity of the Rose
Hill landfill The purpose was to provide an understanding of
ground-water contamination patterns and study possiole remedial
measures
86lt
Appendix A
Precipitation Records
Monthly normal precipitation 1941 -197O
i$l Total monthly precipitation
KINGSTON RI
14
ia
^JO T I bullbullL
pound 111 laquobull
4
a
n
-
^
-
-
KS1JAN
^Ii R3 HB MAR
1
1 APR MAY
1
1 JUN
1981
JUL
-bullraquolaquo H
AUO SEP
K3~~f$s bull
_imdash
i1S 1
OCf NOV OtC
171 1 iI1
JAN HB MAR APR MAY
198
Fig 32 Precipitation Record
- - - -
IM 1 MtvJrflgtlgt c ortli-A t lUN I r nraquo rl - -
gt|MO CLIMATOLOQICAL OUSERV ATIONshyr-r bull JK gt raquo - 1
i5fWA I VAPOR Al IOH -bull AIM If MPCRATUM bullF 0 riccipn AT ION UNO IlMf
bull 14 H 14 H mdash Vshy ADDITIONAL DATA IfUAlUS OATt 1 bull raquof bull bull 1 ta
14 Hw rlaquo4 w bullbull bull 1 114 1mdash4 (llrl 1 1 1fl Hll
0 kmdash
Mraquo M4 raquo i T i 4 bullraquo-laquobull i i
Lgt f 1 21 S 1 Hbull - - bullbull -
ltJL 1 2 01 - - _ _ 1
mdash
-
1 12 _ Q I
mdash shy
mdash 4 (C ( - - fVi 1 - 0
1 (1
^ 1
Vvraquolaquo IJ1^ raquo CP O 3L 1 Z - i bull j-t-J
1 J
LH Vb T n 0
1 gt fl oo O ~l 2 L - bull 1 P )laquo jn iP IP - OOI L5L mdash shy
-t 84 ^(^^ ^fi P i flja 0 JO II 10 tl tcgt 7 J IV wllaquo
h l2L bull 0 lt -_ shy
-id VJ lt 3C 2 ft OOL -mdash
U 71 C1 Sr 2 13 2 nl JLJraquopound HP r M ltf1- (
IMe 2 ii O It
n jlt dl 1 1 bull o o-il ST i 1 i 25 2-x-1
-
ri
i tlL O mdash gtbull bullgtlt 1ft -o- is Oil So iJK 2-io otv u 31 fil loi 2 il Oll it Of wr is i1raquo -iZ 1 deg|0 01
M IT So - mdash
- 13 1 CT mdash i - mdash 21
shy
Tl Ci av ZUll IMT 0 IM Pe v _ 1) T) S) ii3( dlt Ii 2 lt^2 II li- S1 riivi To 7HX lt3lO 14 ^2- iTi I li 011 -- - -i -^IS no 5^ or i | T Jift laquoV OoH bullla It Va iCO mdash L OIL 11 bullvf poundgtpound lS_ flv oh P-lfe 1 poif _ shy11 IB kl (4 itlaquoT lamp llt0 oot^
mdash -n
It T1 |ir( L1 HI 2 0 oil
U 1M ft go C ICf^ -^2 Z laquo-|o
11 it 5 bulln - TO o abull Li u-i IT1 -- Iw O ltM (I bullbull bdquo-I(K 1mdash -tilltLlA ttfe
i Dgt ac -- U 44 4 11 1 1- ytd i i_i J-K 0 i if -i i i V t Wl raquoOHM 1-1 US D C P A R T M f N T OF COMMfRCE t 4 1 IUII 1 1 ^~) mdash
llaquo- Hi NC bull bullh bull bullJL^V HBl CO 00
11
)jLsVyr^gturv
^ | TKu
|-_t_ bull(
IIMgt I I Mt|UU III- II 11
PNECIPITATIOH
I 1 1 IMX
IMO
bull llfclaquo I UCIUKI) Ur C V A r U M A AHO CLIMATOUOCICAL OBitH
E V A F O R A T I C r i Jttffl laquo amp hMIlaquoJllaquoJIIlaquoBgt
DATE AOOITIOMAL DAIAKMAKk M
bullraquobullmdashlaquo
tp 01 (1 Of Ll OOI ooo
0^1 o-i 10 tl |00 102
OC (1 13 Ofl
it i rc DS os an
(1 SV o
Ul 010
(ISl 101 I on
130
II 5= Otl
ss lt 001 (IK Ml
jt il HIT
7 it
ow Wo 17 Top 2-01 OIO
(0 oov zi oot
u CO ^A 0 to Zoi CLflS
bull50 01 ljtj
nshy 5H LO OIt
50121 IVO QJO
14 Co Ho LO Hl ^pound Jl 1
ltM ool fllc
H Tl 01 II
11 11 Q1
iH OIO
HO 2 llaquol 11 II
lifc
IV-IIM ul OIPAITHINT or COHMIICC NOAA
NAtlOHAL gtIATnlaquoll raquotraquoVlClaquo CD
r~
All TCUMMATUNI ^V UII rgt ITmi 1 Cwphu Obic i gtn t ngir-H 30
rilCiriTATIOH
JJ T I rTJ-rimdashr-iramj|MP CLmATOLOQ
laquolaquo jftilCiii bullIHO
Oi1l ADOITIOHAL DAIAlllu
Ilf4ft
Sii1
(1 2 IO OO
Hl ii SO
us OIM
Q^L
a A3 Hi SZ Sf^ bull 12J2
HI Z-SF OOl 1C t HM IA H ICP fiJA
OOl 10 (310 sn 310
if HI (0 ^01
bullit SO 28H poundJ1 11 006
14 35 TX oon II (bull2 it zr II c-S
rr Zll lo 31 OP an 31 a 31 oor
CSW O-ll Si CC Of 011
Oll _ I |ft
00
u i oerraquolaquoTMiMr of c NOAA
NATIONAL K C A T N C M SCMVlCC
TC^S lk)oiVroTJA
TETT I 7X
1raquolaquolaquo 4 bdquo ir lt er ni I^OV ltqgl j--^ TQ
MICiriTAllOH ITIND
D|mdash
b5NO ctiUATOtoiCAL oeit^
OATI AOOITIOMAL OATAVlHAtt
0-tt
Mlaquoh bullbullbull- rshy laquo
I- ltltriu HI I 4 bulllaquobullbull1
Zii
30 Dfellt otvt
at HA
OOI
62
iJ_S2 HI if
bull- 20 SI 2i So
So
VVfr
OSfc
I (
Jtlt
3aoi
r j -bull ie MA
Irill iiol
in^ 14
Mo
Zll
214
21 1P
00-i
bulliron
17
bullr
11 i ir- I J Ktf^c
US D E P A R T M E N T OF COuMEDCC I | C gt A A
K AIlaquo Ttupf lATuit r
|SlVi AlJ PIICIPITATION
oJud (El
VIM i Uraquo
MIND E
EVAPORATIOH flnrft bull A ftufiifccdll
KECORO OF eVAPllHAtlil bull I CLIHATOLOOCAL OBSERVA ^Hij
14 MM A_M AOOIIIONAL DATA11 MAIM
Mr bullH Oo|
M Si lift
bull221 IHI
ZS Ji 40 IZV
icr KS I
HZ 111
bullT 21
loA UK JA IP
v^ ft
1M 2Sshy IT Tl
71 V |
i I 31 1deg a
uty^ U bull3
ons 1 CiO TxX
HHO (10
3H 19 12 10 IP
raquo3H raquo | 5t io
OP OIT
14
vO UI Of PANTMINI Or COMMCRCf MM O A A
F ngt TIHH
iiicffwiffc 4 rJ (TIM bull Cempltit Obitittiio
AIlaquo TIMHIATUM PHICinTATION I V A f OK ATlPrl
OATI ADDITIONAL DATA KMAlIt
U4laquo4 +
03H Ji
10
rc a 1 16 oi ii
tiiy 10
OI
II i23 or o 13 -y~ou HO
II 3V III i 3 t
V laquop oot
OM1 SS ne
T an -i IP
Olt zr LTV
3T 001
a -11 2T
10 an 31
-1 raquo 131 UP 3H lf 14 Lpoundshy
it 14 30
IS
Ui O I P A K T M f H T OP COWlf ICfM O A A
NATJONAI V C A T M C n f t K M V l C K
bullbullbullbullbullshy -2 o AIlaquo TIMMRATUM f fKICIPITATIOH
OATI poundt- MMINMAL DATAk
ZP 51 lo icr
011 111
OoT IHf
Ut 003 am
3o 13 ao
4A X 05shy
H4 i IjJyiV131 ooc js
IH oi 01 tL 18 13 a
No 11-7
rivgtp OO| M Hi 03 01
It 12
bull I 41 bull7119 14 ^^ raquo 31 15 lampk n M ho i
Jo -j-
-J
I
Ml H^ I _
amp2ampUi^= LS 0 S 0-f bullTTT
-Vmdash gt U_ bull 1 rOHM I- 11 OI OCPARTMlNT OF COMM(NCC
HO NATIONAL W f A T M f H ftfraquoVlCI
98
Appendix B
Boring Logs
99
X iHECT 1 ff 2
OAT American Drilling amp Bor ini I Co Inc
wo WATH smn EAST PR ov IDENC E ft 1 Town of South Kingstown South K ngstown R I MOLENO X-J
TC 100 RCSS bull ujrMonitorinq Well Installation | South Kinqjtown R I UNC a STA Pf KXICCTHJ LOC ATK3N
bull cfrserrr TO above S MPLES S FNTTO _ _ |laquolaquor A-109 SURF ELEV RE PORTSEr
GROUND WATER O6SE RVATC MS 1 CDREraquolaquo m-T nn75 laquo A 256 - 20 mdash Hew y
Instolled 32ofT-l2 PV C - JO- COMPUTE 111275 K toia 3- I-WI 1-38 TOTAL MRS bdquo10 screen BORING FCACUAM J K lanq MAI rraquo HomnwWI 300 140 IampPCCrc Mamlaquor Fall 24 30 lampaaiona SOLS ENGR
LOCATION OF BORING H ONITOKING WELL
Coung Samplt Tjp Blow per 6 Manure SOU IDENTIFICATION Strata SAMPLE ^^^yV Bloot
foot
Otptni
From- To
el
l
on Sampler
0-6 1 -6-13 12-18
Dentity or
Conmt j
Chang Remark include colo^ graaation Type of tod lie Rao-coMr type condition nordshynetiDntotf time leamt and tie No Pen Rtlt
2 No top sample 5 12
1 loamy fine sand
bull)^ 40 30 36
5- 616 0 23 20 16
noist iense
Brown fine to coarse SAND some fine to coarse gravel Trace silt
^
1 18 18
36 8-0shy57 40 30 V 35
|0-||-6 D 14 24 20 Srown medium to coarse SAND Some fine gravel cobbles
7 IRshy 16
27 75 37 3
IS- I- D 5 14 16 3bull
ISshy 15
42 50 I9--0shy50 65 20-2ll-6 D 9 23 26 bull Jrown fine to coarse SAND Tbullwshy 1Z 75 90
22-0 Trace silt trace fine gravel
124 120 74 60 52 41
7S-ltlaquoil-A DX 71 16 13 wet very dense
Gray-brown fine to coarse SANC Some fine to coarse gravel little silt
H IR u
40 30--0
3C-30-IO
3l4-334
334-3314
38 4-434
D
c
C
C
7 IflO
94 6
we tr j
y se
ft irox
30MOshy
31 -4shy
Gray-brown fine to coarse SAND Trace silt
Gray-brown fine SAND some lilt trace fine gravel
Too of Rock 31 -4shy
Gray-pink GRANITE
6 7
amp
CJ
IltJ A
60
601
IQ mdash
2(
4
5 i Hard
ft 5ome seams bull
GROUND SURFACE TO J 4 U3CD_ ^JVrf bullbull( tutu t to 4o 4 SampM Type Proportion UMd MOB Wtx 3 OfaM on 2OD Sampler SUMMARY-
OOry CCartd WltWen4 Hoc OlolO Canmonieraquoi Don any CoKeem CarMWncy Earm Barrlaquoj 11 14
UPgtUnOigtturod Piuon trite (Oto20dego 0-Kgt Loei it 0-4 Sait 3O+Hofd Rock Corng 14 Kgt-30 laquo4 0 rte 4-8 MSHM Samplet TPTtitPit Ai Auger Vvanefett tarn 2Olo39 3O-M Owlt n laquo-lS Strlf rinit nn v 1
UTiUndlshffbed ThrMOll and bull 33to9O 5O Very 0laquo nraquoe 19-30 V-3trraquof - | OLE NO X-l
TOVH rim - iA it raquotoraquo
100
SHEET 2 o_L
WO WATEt STUET [AST ft OVIDENC pound a i American Drilling amp Bor ing Co Inc
MCLl WQ X- 1 Tt AOORCSS i
LIME A STA KXICCTMJ tuf same as 1 | tame as i LOCATION
W PORTSEf mo OB nj urt eflaquo T
illtPLES S
P
CVTTO nlaquo mun orv
^s f^ Tin i GRCVMO WATER OBSERVATONS CASING SAMPLER CORE BAR
START Typi COMPUTE tome at 1 same aiH
TOTAL MRS BORIMG FOR CMAN n bull IT INSPECTOR SOILS EMM
LOCATION OF BORING u HfVJTneTfi UFI _
8
Counf Blo-t
foot
Dtpllo
From To
0( on SampMr
0-6 f 6-IZ
Moittir
Oonuty or
Contilt
Strata Ctnngc
SOIL OCNTiriCATION Rtmorkt ineHifl cotot grqdotion Typlaquo of Mil etc Roo-axtrPlaquo condition Mrdshynlaquot Drog tun ttomt end tic
SAMPLE
No Ptfl RfK
434-4o4 c
approx 7 minj
per toot 454
Gray pink GRANITE Hard Fairly solid core
lt_4 24
Bottom of Boring 45 -4
-
~
bull 1
GROUND Sorrow Tye
SURHCZ 10
bull OiOry CgtCord WWothod UPUnditiurMd Piston TPlaquoTtraquotPtt AtAuotr VVor
UTltUndinrvd TTMMO bull bulltat
iivnPilaquo(onioni Uraquot4
me OioiOItttt laquoraquo20
wmt Z0ie33
and 361090
c M
C1 5 Si
-SOshy
ASING
IOtgtWtigt bullnlot Dn 10 Loci M Mod 04 SO Dm 1shy Viry 0laquo
s _
TMEN 0 hMl on 200 SoiTBUr laquoity ConcMMt Conorawncy gtbull 0-4 Sort 30shym 4-B MStlfl M BH9 Strtf bull ts-so v-swt bull
t-HOrt Ear Bern RoetCorrt
i ^^^^^ bull
-[MOLE no x-i
101
raquoMEC rAmerican Drilling amp Bor in g Co Inc 1 ofj_ DATE wo WATlaquo smn UST Plaquo IOIDCNC j laquo i
Town of South Kingstown South Kingstown 8 MOLE MO Jlt Z TC rx MCS3
rtprr uAurMonitorina Well Initollation | South KinqitowrxRI UNC A STA P KATIOM ME POCT ^rwT TO above I OFFSZT
uD^r laquorlaquorTTO 6 -109 suw tLEv Sgt louffJOCNO
0 tj Tlmlaquo WOUND WATER 06SCRVATC US gtW Rsdl SING SAM^EH CORE BAH
26 ^_ 12 $TAlaquoT UL 2Z2i Ji r TTP NW ltA sr IJZC Z5 CCOMPLETE
SitLO 3 I-3B- 1-38 TOTAL MAS 41 BOAINO FOACMAN JK1 ana nf ni n MonwwWl 300^ 140 BIT bullK^CT
gttonvrar Foil J^laquo 30mdash Diamond SOOJIEMGM
IE HFII
iCaunq SampM Trplaquo BMMtpw6 UOIIIK- SOIL DCMTIFKATION Siraia SAUPLE Blow DlaquoPIAraquo of on SompMr HtmorU mcJuo cotes gradation Type of Dwuily
pw or CXang writK Roel-eolorlyp condition tvort-From- To Vfoot 0-6 f 6-2 12-18 Coniitt egt rwtiOnAngtimt wamaondtte No Praquon Rtlt
2 Brown fine SAND little silt 2 2-0shy5 15 18 moist Browi fin to coarse SAND 18 5- 6-6 0 14 25 27 vlaquo Troc fin aravel | 25 wy Ifl 11
dlt tns 35 40 38 moist n in-il-i Lgt U 15 18 ie is li1 Irl IS 31 I2-0
~~43 1
A) Jrown coars to medium SAI MD 48 moist Little fine to coarse gravel
|5-IA-Xlaquo 14 47 41 fn D laquo y Little silt rrqa coarse sane 3 18 I1
68 In IS 44 32 34
n ^n-^i-A- w 2o 19 29 wet 4 la -59 lens ltfO no
25-0 2amp bulllaquo- 77 c BOULDER r[ 4 i
27-0 5X ~W 24 24 bullWar- 5 Ifl irown tine to coarse SAND some
dens 29-0- Fine-coars gravel trace silt
30-3I oxx 30 32 30 moist irown -gray fine SANDiom e 6 l rr Vlaquoy 31 -0 silt trace fine oroveTILL
Bottom of Boring 31 -ampbull shyBent casing -pulled out and moved over 4 - washed amp tJrovlaquo casing to 30 -Installed 3C gtof 1-12- PVC - 10 screen
WOUND SUraquoraquofCE TO 3pound 1 yijfD MW t ASIMC TMCJ laquo olaquorod -bor of borina
SomoU T]Fplaquo ProigtuliOraquoH UMd MIOtgtWLx3Orolt lon2OASanlaquoMr SUUMARY-D=Dry CCorad Wlaquoworaquonraquod bullact OiaiO CanM gnMM Daonty CIMIH Caamraquoci EffW 8or^ 2pt
UPiUnairurMd Pition Itnt laquoM2O O- O UKraquolaquo 0-4 Soft 3O-hHard Roelaquo Corrig o- JO M0mlaquo 4-8 MSNff SOTipM 1 p^ 3O-9O OwgtM bull-IS Slid
TPlaquoTraquojraquoPit AAugtr ViVon mini tamt 20to39 UTtundiifir6d TrwMOtf and JSloSO 50-raquobull Vary 0nlaquo [HOLE NO x-2 B-3O V-3Mf lev rim - IAIT raquosectlaquoraquo
102
300 iu 24
1 UMnii ffi 140 laquo 30
CA1INC tf
gt taWCTf
bull 0gtlaquo i R Cook Jr_ R Millineton1 Wttn
I~
1 VAMtl CtMG
1 W HO-t MO
1 Oraquo 1 laquo0~ twt
L 1 laquo-raquo VfcM^lf [wlaquoraquoCI ^ ^ K3Ot III laquo
0-LS D
5-65 D
LlQ 10-115 D
15-16 Tgt
Lraquo 70-51 n
25-26 D
F
I O-O Ci
A Allstate Drill ins Co vi o i
PROVIDING R 1bull raquoraquo uvraquonn~ N M O M I T O P I N G HE1 _^lt -^ PI-Traquo UJU
CUM Town of South Kineraquotown raquoraquo 1 1TA maoer Propolaquolaquod Sit for Slude Disposal nltn
laquo V-449 iampAAtut i a 138 ort STI bull r 42777 CtOuMO IKVtllON
Cill bdquo 258 DA II MN ru 42777 rilaquolaquodO laquoraquoTti rum 1911
AU1TATI
MMUI1 raquolaquogtlaquolaquo laquoKiO itXHHKraquoriOi of sous MUAHI nMTKlion Ot CMlaquoMC|kOraquort tl CO~VH DXltgt raquomlaquo laquotf IMi COIOI C4l II I 1raquo gtlaquo^ Oraquo 1Ol rC t Xgttgt VtfKOe Craquo Mi 1 ft liMraquoK laquo0^tlaquot nfgt
1-2-1 10 TOP SOIL FINE LIGHT BROWN SAND traclaquo of ilt
16-31-17
22-24-21 100 FINE TO MEDIUM LIGHT GRAY SAND trace of fine gravlaquol and raquopoundLt
lfl-37-34 150 LIGHT BROWN FINE TO MEDIUM SAND little poundinlaquo gravel
21-17-15 200 MEDIUM TO COARSE SAND bullomc fine gravel
12-4-10
265
Observation well installed
NOTE No casing blows taktn
bullbull B-23 ow
^w^ 265 I raquo bull raquolaquo bull I W
11 laquot gtbullraquo Vlaquo 14 W gt_ c-shyji bull alaquo bull jraquo VI laquoHshyw bullbull m raquobullbull D-6 raquo Mshy
bull bull laquo Vshy
1
bull bull
I
103
MAMMII Allstate Drilling Co ulaquorr 1 or 1 FftOVIOCKZ H L traquolS mTArm^S MONITOR NR WEL
VNO wr3JJO__raquoraquou_24__ HCU MO P-74 n iu riBwi Town of Slt7H^ Xirpin
mdash^ laquo0J P 1 1 bull ^n^ciit^o TVlaquow^laquott1 bullraquoit wt 140 nu 30 olaquor fBu lkv Waste Disposal Arcai
MUTAH a V-449 R Cook Jr UMlaquoiigti D 1 38 0t| raquoIJ raquo 5277 rlaquo SUMO luvlaquorv-laquow
mdash 5277 fipe -raquoT pfpm 150
H MCIO IMNTlXAflON Of SOU t(kAIlaquoS rrn 0-laquoraquo
5 -SF 01 w in laquobull -raquo ^ lit
D 1-2-2 TOP SOIL V-1-oraquo
15 IPbull FINE TO MEDIUM LIGHT GRAY SAND AND GRAVEL
5-65 D 37-27-35 some silt
10-11 D 20-14-18
15-165 D i 17-14-14 155
BROWN COARSE TO MEDIUM SAND little fine to coarse gravel trace of silt
20-211 D 4-4-2
230 GRAY BROWN VERY FINE SAND
25-26J D 7-8-9 AND SILT 265 fvarvedl
Observation well installed
NOTE No casing blows taken
wta 10 n uuraquo c^imdashbull IgtM laquolaquobull- B-24 ow ~ 14 ltfc laquoraquobull vlaquo^ M laquobull r O 0 fmtt bull W-L 26 5
-0- CgtCmdashgt bull laquolaquobull mdash laquo 1 - raquoraquo 1 gt 1laquo bull 1 gtraquor to bull mdashbull bull bull bulllaquo I t l~laquo 1lt Uraquo mdashbull ) bull 1 gtbull ft 0~ H laquoy bullM ta bull -IN la laquobull OPUM bull($ IMI
mdash H raquo laquo-bull
104
Appendix C
Calibration of Specific Conductance Meters
105
Specific conductance measurements were made using a beckman RB
338 temperature compensating meter and a YSI rtooel 33 salinity
conductivity temperature meter The YSI meter is not
temperature correcting A formula to compensate for temperature
differences to standardize YSI measurements was used (21)
A long probe for the Beckman meter was used to measure conductivity
in the wells Differences in conductivity between the YSI ana
Beckman meters and the Beckman short and long probes exist These
were calibrated in the laboratory using 001 N and 01 N KC1
solutions Values presented are Beckman short probe values The
Beckman long probe values were reduced by 76 and tne YSI values
were multiplied by 11 to adjust to Beckman short probe values The
YSI meter was used in the latter phases of the study for the
stream contamination due to the greater accuracy of the dial readout
scale
Table 7 Specific Conductance Meter Calibration Table
Concentration (KCL) 0001N 001N
Specific Beckman short 145 143 143 1247 1245 12GO
Conductances Beckman long 190 191 188 1639 1650 1665
umhocm 9 25 C YSI 132 131 128 1131 1140 1150
average values Beckman shortBeckman long = 075
Beckman shortYSI = 11
106
Appendix D
Computer program Flow Chart
107
F1g 33 Computer Program Flow Chart-
1TpoundR MAP TCO
NEWPER
WEWSTP CZAX
HEWIT TRANS TCOF ROW COLUMN
Yes
Yes
108 The following is a description of the USGS two-dimensional computer
program Iterative Digital Model for Aquifer Evaluation updated
December 1972 by P C Trescott The program written in Fortran
consists of a MAIN program and six subprograms or subroutines which
themselves are organized into subprogram sections The subroutines and
their sections are listed below
MAIN Program
DATAIN (subroutine) COEF ITER (section) CLAY MAP TRANS NEWPER TCOF
ETRATE COMPUT STORAG
NEWSTP LEAKAG NEWIT1 NEWITO CHECK ROW CWRITE COLUMN STEADY PRNTA OUTPUT DRY BLOCK DATA
The program begins in the MAIN program which controls the sequence
of passage to the subroutines Sequential steps are described in the
program as shown in the flow chart of Fig 32 Emphasis is placed on the
steady state confined aquifer case as applied in this study First data
input is read in the DATAIN subroutine This data includes transmissivities
or permeabilities starting heads storage coefficients and grid spacings
Nodal transmissivity values are then computed for the water-table problem
in the TRANS section (COEF subroutine) This procedure is necessary here
because the subsequent routine for computing iteration parameters (ITER)
keys on nodal transmissivity values which would not have been input to
the water-table problem In the water-table option these would have been
109
computed from given bedrock and water-table elevations to obtain the
saturated thickness component of the transmissivity calculation In this
study water-table option was not used and the transmissivity values were
input directly The program then passes to the ITER section (DATAIN
subroutine) to compute the iteration parameters which expediate or even
cause convergence Next the MAP section (DATAIN subroutine) is utilized
to initialize data for an alphanumeric map if this was requested in the
input options Transmissivities are then computed for the confined
(artesian) aquifer case (water table not specified with input options)
in the TCOF section (COEF subroutine) These coefficients are harmonic
mean values of adjacent nodal transmissivities weighted by grid sizes
Time parameters and pumping data for a new pumping period are then read
in the NEWPER section (DATAIN subroutine) followed by entry into the
NEWSTP section (COMPUT subroutine) which calculates the size of the
time step Leakage coefficients (hydraulic conductivity of the confining
bed divided by confining bed thickness) are next computed in the CLAY
section (COEF subroutine) if leakage was specified in the input data
which was used in this study
A new iteration is then initiated in sections NEWITO (COMPUT
subroutine) NEWITO saves the current head values and compares them to
the updated head values for determining closure This is followed by
nodal transmissivity values being computed for the water table or water-
table artesian conversion problem Transmissivity coefficients are then
computed for the water-table problem in TCOF (COEF subroutine) Total
head values are then computed with the alternating direction implicit
procedure using the Thomas algorithim first along rows in the ROW section
110 and then along columns in the COLUMN section both in the COMPUT subroutine
Then if a solution is not obtained (because the error criteria for
closure is not satisfied) the MAIN program branches back to NEWIT1 subshy
sequent sections TRANS TCOF ROW and COLUMN repeatedly until a
solution at the particular time step is achieved NEWIT1 increments the
iteration counter and is immediately followed by NEWITO The program then
moves to the STEADY section of the COMPUT subroutine to check if the
closure criteria for steady state has been satisfied Output is then
printed in the OUTPUT section of COMPUT if steady state has been reached
or if the particular time step is designated for output
The program then branches back to NEWSTP (COMPUT subroutine) and
moves through the subsequent routines until the last time step in the
pumping period is reached Output is then promoted in the DRY section
of COMPUT if specified in input data If the last pumping period in
the problem has not been reached the program branches back to the
NEWPER section and moves again through subsequent sections otherwise
the program will terminate or start a new problem if one follows
This study was simulated as a steady state problem which can be
simulated by setting the storage coefficient of the aquifer and the
specific storage of the confining bed to zero and using one time step
of any length
111
Appendix E
Computer Data Sheets
RGSEA
10 ROSE HILL LANDFILL MODEL 20 30 40 LEAKAGE 50 60 70 CHECK 80 90 100 HEAD 110 120 1 23 IQ 100 5 001 37E-OU 0 130 100 001 0 0 1 4 0 - 1 - 1 1 - 1 - 1 i i i i i i 1
ISO 1 10 0 1547E-05 01 10 1 1 160 04642 200 200 1 1 i it
1QO 190
CARDS I THROUGH 19 - CODING SHEET
CHEAD
100 110 120 130 131 132 140 141 142 150 151 152 160 161 162 163 164 165 170 171 172 173 174 175 176 177 178 179 1BO 101 190 191 192
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 539
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 58
25
25
25
25
25
25 621
25
25
25
25
25 662
25 25
25
CARD SET 2 - STARTING HEAD MATRIX (FT)
193 194 IVb 196 197 190 200 201 202 210 211 212 220 221 222 223 bull 224 225 230 231 232 233 234 235 236 237 23B 239 240 241 250 251 252 253 254 255
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 23 25 25 25 25 25
25 25 - 25 25 25 25 25 25 25 25 25- 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 - 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25
25 25
25
25 25
25 25
25 25
25
25 25
25
25 25
25
25
25
25 25
25 25
25
25 25
25 25
25 25
25
25
25 25
25
25 25
CARD SET 2 - STARTING HEAD MATRIX (FT) - continued
STORC 1512 FRI 19 FEB 82
100 110 -1 -1 - 1 - 1 0 0 120 130 140 ISO 160 170 100 190 200 210 220 230 240 230 251 260 261 262 263 270 271
CARD SET 3 - STORAGE COEFFICENT
LEAK
100 110 120 02 130 _ 18 02
I ltu 18140 025 150 02015015015 19 deg25
02 160 022 bull-laquo- J1 5 j 1 z laquo- l^
170 015 180 016 laquo02
190 016 OE025
200 02504019022021025 2 5 i S lt03 0252i2 n
230 030 deg23 deg2 deg2 deg2 -02023023 240 022 250 022025025 02
027043 013025
30() 025025025 310 025031 320 024025
CARD SET 5 - AREA OF STEAMBEDAREA OF NODE
120
Appendix F
Bibliography
121 BIBLIOGRAPHY
1 Agpar MA and 0 Langmuir Ground-Water Pollution Potential of a Landfill Above tne Water Table Groundwater V 9 No 6 1971 pp 76-96
2 Allen William B Hahn GW and RA Brackley Availability of Ground Water Upper Pawcatuck River Basin Rhode Island USGS US Government Printing-office GS 66-624 19bb
3 Annual Book of ASTM Standards Part 31 Open Channel Flow Measurement of Water and Waste Water by Weirs D 2034-68 1975
4 Annual Book of ASTM Standards Part 19 Infiltration Rate of Soils in Field Using Double-Ring Infiltrameters D 3385-75 1975
5 Baeaecner MJ and W BacK Hyarogeological Processes and Chemical Reactions of a Landfill Ground Water V 17 no 5 1979 pp 429-437
6 Beck WW Dunn AL and Grover H Emrich Leachate Quality Improvements After Top Sealing1 8th SHwRD MERL Symposium 1982
7 Beckman WK Transient Modeling For Estimating Sustained Aauifer Yield master thesis presented to the University of Rhode Island Kingston RI 1978
8 Bhattacharya PK and HP Patra Direct Current Geoelectric Sounding Elsevier Publishing Co New York 1968 135 p
9 Bouwer H Ground Water Hydrology McGraw-Hill Book Co New Yoric 1978 p 378
10 Braids 0 Cocozza pound Fenn D Isbister J Rous P and B Yarc Procedures Manual for Ground Water Monitoring at Solid Waste Disposal Facilities Environmental Protection Agency530SW-611 Cincinnati Ohio 1977
11 Cartwright K and MR McComas Geophysical Surveys in the Vicinity of Sanitary Landfills in Northeastern Illinois Groundwater V 6 no 5 1968 pp 23-30
12 Cartwright K and Fd Sherman Jr Electrical Earth Resistivity Surveying in Landfill Investigations Reprinted from Proceedings of ohe lOtn Annual Engineering and Soils Engineering Symposium Moscow Idaho 1972
122 13 Clark TP Survey of Ground-Water Protection Methods for
Illinois Landfills Groundwater V 13 no 4 1975 pp 321-331
14 Dunne T and LB Leapold Water in Environmental Planning WH Freeman and Company San Francisco 1978
15 Faro DG Upgrading Hazardous Waste Disposal Sites Remedial Approaches US Environmental Protection Agency500SW-677 Cincinnati Onio 1978
16 Fenn DG Hanley KJ and TV Degeare Use of the Water Balance Method for Predicting Leachate Generation From Solia Waste Disposal Sites US Environmental Protection Agency530SW-lfa8 Cincinnati Ohio 1975
17 Geisser 0 An Electric Analog and Digital Computer Model of the Chipuxet Ground Water^ Aquifer Kingston Rhode Island master thesis presented to the University of Rhode Island Kingston RI 1975
18 Hahn GW Groundwater Map of the Narragansett Pier Quadrangle Rhode Island Rhode Island Water Resources Coordinating Board GWM 5 1959
19 Hemsley William T Koster C Wallace Remedial Technique of Controlling and Treating Low Volume Leachate Discharge USEPA National Conference on Management of Uncontrolled Hazardous Waste Sites Oct 1980
20 Hughes GM RA Landon and RN Farvolden Hydrogeology of Solid Waste Disposal Sites in Northeastern Illinois Final Report to US Environmental Protection Agency PUD SW-l^d Cincinnati Ohio 1971
21 Keller GV and FC Frischknecht Electrical Methods in Geophysical Prospecting Pergamon Press New YorK NY 19bb
22 Kelly WE West Kingston Landfill An Evaluation of Its Effect on Ground-Water Quality Rnoae Island Water Resources Board Water Information Series Report 1975
23 Kelly WE Geoelectric Sounding for Delineating Ground-Water Contamination Groundwater V 14 No 1 1976 pp fa-10
24 Kelly WE Ground-Water Pollution Near a Landfill ASCE Environmental Engineering Division Journal V 10 No EE6 Dec 19b pp nay-nyy
25 Kelly WE personal communication January 1982
123
26 Kelly WE and OW Urish A Study of the Effects of Salt Storage Practices on Surface ana Ground Water Quality in Rhode Island NTIS FHWA-RI-RD-8001 1981 54 p
27 Kimmel GE and OC Braids Leachate Plumes in a Highly Permeable Aauifer Groundwater y 12 no 6 1974 pp 388-393
28 Klefstaa G Senalein LVA ana RC Palmauist Limitations of the Electrical Resistivity Method in Landfill Investigations Groundwater V 13 No 5 1975 pp 418-427
29 Landon RA Application of Hydrogeology to the Selection of Refuse Disposal Sites Groundwater V 7 no b 19b9 pp 9-13
30 Lang SM Bierschenk WH ana WB Allen 1960 Hyaraulic Characteristics of Glacial Outwash in Rhode Island Rhode Islana Water Resources Coordinating Board Bulletin No 3
31 LeGrand HE Patterns of Contaminated Zones of Water in the Ground Water Resources Research v 1 No 1 1965
32 Palmauist R and L Sendlein The Configuration of Contamination Enclaves from Refuse Disposal Sites on Floodplains Grouna Water v 13 no 2 1975 pp 167-181
33 Pinder GF A Digital Model for Aauifer Evaluation Techniaues of Water Resources Investigations of the US Geological Survey Bk 7 Cl 1970
34 Purushattam D Tamxe GR and CM Stoffel Leachate Production at Sanitary Landfill Sites ASCE Environmental Engineering Division Journal V 103 no EE 6 Dec1977 pp 981-988
35 Remson I Fungaroli AA ana AW Lawrence Water Movement in an Unsaturated Sanitary Landfill ASCE Sanitary Engineering Division Journal v 94 no SA2 April1968 pp 307-316
36 Rosenshien JS Gouthier JB and WB Allen Hydrologic Characteristics and Sustained Yield of Principal Ground-Water Units Potowamut-Wickford Area Rhoae Island USGS US Government Printing Office GS 67-324 1968
37 Roux PH and B Vincent Electrical Resistivity Evaluations At Solid Waste Disposal Facilities US Environmental Protection Agency SW-729 Cincinnati Ohio 1978
124
38 Salvato JA Wi lk ie WG and BE Mead Sanitary Landfill Leaching Prevention and Control Water Pollution Control Federation Journal v 43 no 10 Oct 1971 pp 2084-2100
39 Sawyer CN and PL McCarty Chemistry for Environmental Engineering McGraw Hill 1978
40 Stellar RL and P Roux Earth Resist ivi ty Surveys - A Method for Defining Ground-Water Contamination Ground Water v 13 no 2 1975 pp 145-150
41 Todd OK Ground Water Hydrology John Wi ley and Sons Inc New York 1959
42 Tolman AL Ballestero AP Beck WW and GH Emrich Guidance Mannual For Minimizing Pollution From Waste Disposal Sites US Environmental Protection Agency-500SW-677 Cincinnati Ohio 1978
43 Trescott PC Iterative Digital Model for Aauifer Evaluation US Geological Survey Open file report 1972
44 University of Rhode Island Academic Computer Center CalComp Contouring Manual
45 Warner DL Preliminary Field Studies Using Earth Resistivity Measurements for Delineating Zones of Contaminated Ground Water Groundwater v 7 1969 pp 9-16
46 White EF A Report to the Town of S Kingstown Utility Survey Engineering Corp 1967
47 Zohdy AAR A Computer Program for the Calculation of Schlumberger Sounding Curves Over Horizontally Layered Media Using the Method of Convolution US Geological Survey Denver
48 Zohdy AAR Eaton GP and DR Mabey Application of Surface Geophysics to Ground-Water Investigations Technidues of Water-Resources Investigations of the US Geological Survey Book 2 Chapter 01 Washington US Government Printing Office 2401-02543 1974
VI 1
25 Infiltrometer Location and Drainage Feature 57
26 Results of Infiltrometer Tests 59
27 Schlumberger Sounding R-l 71
28 Schlumberger Sounding R-2 72
29 No Recharge over Lanafill 77
30 SI urry Wall 80
31 Slurry Wall without Recnarge Over It or Landfill 81
32 Precipitation Record 87
33 Computer Program Flow Chart 107
Introduction
Ground-water contamination of aauifers from municipal landfills
is a widespread problem Contamination of domestic supply wells and
neighboring streams has occured at the South Kingstown municipal
landfill which is located adjacent to Rose H i l l Road approximately
one mile nortn of Peace Dale Rhode Island (Fig 12) The polluted
neighboring wells have been relocated to their present locations to
remove them from tne leacnate plume (Fig 3) Fig 4 inaicates flow
patterns from the landfill which has contaminated streams to the
east and southwest of it The generation of leachate continues as
precipitation recharge and upgradient ground-water sources
infiltrate the refuse To effectively prevent or minimize
contamination from this landfill several remedial options are
available These w i l l be evaluated relative to the areas geologic
setting and hydraulic properties ground-water flow patterns
recharge characteristics and proximity to supply sources
The rate of ground-water flow out of the landfill into the
adjacent aauifer and flow patterns largely depend on tne hydraulic
gradient of the water table and the hydraulic conductivity of the
landfill and aduifer material The hydraulic gradients were
determined by monitoring water-table fluctuations in several wells
located around the landfill and elevation siting in stream
locations and elevations This information enabled a ground-water
map of the area to be developed from where flow patterns can be
developed assuming flow lines are orthogonal to contour lines The
ground-water map in combination with Knowing aquifer and landfill
N
^ooo
feet
Fig 1 Location Map
3
peoy ||H asoa
X ltbull
Alt
f c c
o
^ ^ o o f a
O OJ 83X1
o O
x o
seepage observation -t West
hole Landfill Area
Legend mdash landfill limit bull j--excavation limit r^-s stream copy WNWNEECSeuroSCSEN
monitoring well locations = = = unimproved road
A contaminated domesti supply well
D uncontaminated domestic supply well
feet
Fig 3 Supply Well Locations
5
a 03
N lo ^ gt
laquo c 2
mdash w
3
X o ^
3 O L
o CO
0 opound E bullo
0
co
c
o0
uj ^
0 o o c
o $ bullA
E c o
w
bullo t_hraquo9 O
_OplusmnJ ca
u
pro
ve I 51 H
bullo 0gt
UJ _c e poundbullo Mzbull w gt 0
laquorege cc
0gt -^^ o a5 raquobull bullo o sect 3 mdash laquoo o wcz _
3Ogt c $c o_ X
aw e 05 0 (0 3 bullo
o a 2 2 u
hydraulic properties and the subsurface geometry enable estimates of
ground-water outflow to be made Streamflow measurements were used
to verify these outflows Contamination levels using specific
conductance measurements as an indicator were measured in wells
streams and observation holes to help delineate the extent ana
degree of contamination An electrical resistivity sounding was
conducted in a known contamination zone
The primary objective of tnis study is to determine flow
patterns in the vicinity of the landfill ana recommend possible
actions to contain or minimize the impact of the contamination In
oraer to fully evaluate these goals the aforementioned parameters
were input to a computer model to produce simulated flow patterns
under different conditions The simulated present conditions were
matched with field water table and stream flow measurements to
calibrate the model A series of simulations were then run to
evaluate flow conditions before the excavations anaor landfill
existed Remedial measures such as reducing recharge to the
landfill and implementing a slurry wall to blocx off leachate flow
to endangered wells were simulated to evaluate their effectiveness
Based on this analysis recommendations are made as to how to
minimize leachate production ano best alleviate the immediate danger
of the contaminant plume spreading to unpolluted domestic supply
wells
background
The South Kingstown landfill is in a geologic setting that is
very similiar to the nearby West Kingston landfill This is located
about 3 miles west of the South Kingstown landfill and has been
studied to assess leachate effects on groundwater quality using
specific conductance as an indicator of contamination levels
(222ltt) Both sites were located in abandoned gravel Quarries which
were filled in with refuse to create the landfill
In the literature numerous authors have shown that the character
of contaminant plumes from landfills are largely dependent on the
local geology and geohydrology A study on Long Island (27) in
similiar glacial material illustrates that the Quantity of flow is
dependent on the hydraulic conductivity of tne aauifer the
hydraulic gradient and the vertical cross-sectional area of the
aauifer it flows through This is expressed as Darcys Law (41)
Q = KIA
wnere Q = flow quantity
I = hydraulic gradient
K = hydraulic conductivity of the aauifer
A = vertical cross sectional area of the flow area
Specific conductance was used as a contaminant tracer to show that
the plume from the landfill flowed downgradient and vertically
through the full thickness of the aauifer A study in Iowa (32)
indicates that the size ana shape of the contamination outflow from
a l a n d f i l l can be predicted from existing geohydrologic conditions
and that the horizontal shape of the outflow extends downgradient
8
from the source and parallel to ground-water flow lines Other
parameters which control the extent of the contaminant plume are
dilution and dispersion in the aquifer and the adsorption properties
of the aauifer material (31)
The amount of leachate generated depends largely on the amount
of water that infiltrates through the landfill to increase tne water
content of the refuse in the landfill The precipitation recharge
that percolates down through the unsaturated zone to the water table
moves in a vertical direction (35) Surface runoff soil moisture
storage losses and evapotranspiration account for tne precipitation
that is not transmitted tnrough the unsaturated zone of aeration
(3315) Upon reaching the saturated zone the water enters the
ground-water flow system Ground-water mounding has been reported
in landfills due to the decreased hydraulic conductivity of
compacted refuse relative to surrounding aauifer material (20)
Chemical processes within the landfill leachate outflow and
surrounding soil cation exchange capacity relative to water duality
of the surrounding aduifer have been studied in Pennsylvania (1) anu
in Delaware (5) A procedures manual for ground-water monitoring at
solid waste disposal facilities was developed by the US
Environmental Protection Agency (USEPA) (9)
Several reports have been written that investigate site
selection design criteria and remedial measures to correct
leachate problems (29) A survey of ground-water protection methods
for landfills in Illinois studies relationships to the water table
theory of liner installation and monitoring devices (13) Sanitary
Landfi11-Leaching Prevention and Control presents a review of
preventative methods such as means to minimize infiltration
interception of ground-water and other pollution control measures
(2 37) A study in Pennsylvania on actual measures implemented to
collect and treat a landfills leachate discharge presents a site
specific study (19) Leachate Quality Improvements After Top
Sealing1 shows that by minimizing infiltration at a landfill in
Connecticut the outflow leachate water quality can be improved
dramatically and contamination plume reduced significantly (6) The
most comprehensive reports on remedial approaches to upgrading waste
disposal sites and ground-water protection methods have been
compiled under USEPA contract (1542)
To assist in evaluating remedial measures the US Geological
Survey (USGS) computer model Iterative Digital Model for Aduifer
Evaluation was used It was originally developed as a model for
simulating two-dimensional aauifer problems (33) It had been
updated since its original development to accomodate different
options (43) This model has been applied to glacial outwash
regions in Rhode Island (717)
10
Description of Study Area
A map of tne landfill area (Fig Z) was obtained from tne town
of South Kingstown The excavation to the west of Rose Hill Roaa
the landfill area directly to the east and the presently operating
area to the east of the central stream comprise tne overall study
area This study will concentrate on the west landfill area whicn
has recently reached capacity and been closed to further dumping
This site received mixed refuse for the past 15 years The depth of
the excavation where the landfill presently exists was approximately
to bedrock in some places Tne exact depths of landfill material is
unknown
The landfill cover has been graded and sloped generally eastward
to convey surface runoff to the eastern side A sandy soil that was
excavated locally was used as tne cover material The northern
section has a vegetation cover and the recently filled southern
section has been seeded and mulched The six monitoring wells W
NW NE EC SE SC were placed by the town of South Kingstown to
provide water quality information
Referring to Fig 2 the west excavation stream drains the area
created by the excavation to the west of Rose Hill Road and flows
throughout the year The central stream drains a small watershed
area which lies to the northwest of the landfill and drys up during
part of the year These streams flow into the Saugatucket River
which flows throughout the year and is larger than the west and
central streams combined
11
The USGS Groundwater Map (18) was initially consulted to proviae
information on the ground-water flow patterns (Fig 5) and the
geology of tne area (Fig 6) The surficial geology borings and the
vertical geologic cross-section at the base of the study area
indicate shallow water table and bedrocic and a nearly constant
saturated thickness (18) Boring logs at the W well ana a point
approximately 150 feet south of it indicate glacial outwasn material
which is primarily sana with a trace of gravel over bedrock at a
depth of approximately 33 feet Borings at the east landfill area N
and S monitoring wells indicate the same aquifer material
(Appendix B)
The ground-water map developed by Hahn is taken as
representative of conditions existing prior to the excavation of the
I l andfill (18) This indicates water-table contour lines that run in i
a general northeasterly direction This means tnat flow was
originally in a southeasterly direction However contamination of
domestic supply wells on the west side of Rose Hill Road has
occurred (Fig 3) strongly suggesting that the original flow pattern
has been altered by the excavation to the west of Rose Hill Road and
the landfill to the east of it Domestic supply wells were formerly
located directly to the west of Rose Hill Road but were aoandoned
when they became contaminated from landfill leachate New wells
were located to the south and west away from the contaminant plume
of tne landfill In addition a well located at the northeastern
corner of the landfill was contaminated and a replacement located to
the east of Us former location on tne opposite side of the central
12
Legend scale 124000
mdash-40 mdashground-water contour elevation
Fig 5 Ground-Water Map
13
Legend feet
TILL
Fig 6 Geology Background Map
14
stream This second wel 1 also became contaminated Domestic supply
wells located near tne northwestern corner of tne landfill and
approximately 300 feet south of it nave remained uncontaminated
These well locations serve as an indication of tne extent of the
landfill contamination which is largely dependent on the groundwater
flow patterns To furtner investigate this problem and provide
substantial information on which to base the geohydrologic analysis
field studies of the area were conducted
15
Field Studies ana Procedures
A map of the lanafill and an aerial pnotograph of the area were
obtained A tracing of these maps superimposed upon another
delineates stream landfill and monitor well locations (Fig 2)
The field investigation concentrated on the west landfill area ana
its aajoining streams ana monitor wells The east landfill area and
the three monitor wells in that area are induced in the latter
phase of the study in oraer to expand the model area
A traverse which establishea tne monitor well elevations was run
using a Carl Zeiss level These were originally sitea in by the
town of South Kingstown using a local USGS reference datum number 40
(18) The wells of known elevations then served as benchmarks for
referencing adjacent stream elevations This in combination with
the depth to water table measurements at each well enables tne
water-table surface geometry of the area to oe visualized
Water-table measurements of the west landfills wells were recordea
over a ten month period to record fluctuations (Fig 7 Table 1)
The east landfill areas wells were monitored for a five month
period Using a given water-table condition a ground-water map was
developea of the area (Fig 4) This indicates an outflow from
the landfill primarily in a southeasterly direction and partially
in a southwesterly direction
Additional bedrock and water-table information was ootainea by a
seismic refraction survey at several locations along the landfill
perimeter A Bison Model lb70C Signal Enhancement Seismograpn was
used to maxe the surveys Lines were run (to a length of kOO feet)
16
17
w s p bdquo S bdquo s S S a laquolaquo _
s 2 8
V
r bdquo
3 s a
-R s
S
S 3
t
raquobullraquo
S
5
K
r
~
3
K
pound
7
S
bdquo3
C 5 S
shy raquo S s
1 3 s 3 2 5 ^ bull
5 m
s o
^ 3
raquo
--
R bull 5
s pound J O s
5 a 3 7 3 m
5 s a ^
iraquo a s rlaquo
M ^
^ c o 2 5 s 3 a S R
rd 3 y a O =J
^ bdquo
JJ s s 3 bull ~ I
~ s 5 3 a s a
(Ogt (U
2
-t =
r s s in
5 y
a s
5
3
s
5 a
^ a
3 a 51 a bullbull
sj 5 Ml
3 a bull
s raquo
a
0)
0
^ mdash
a j -
-3
C
g S
S
bull a
-
~ 3 o
2 s s 3 a bdquo s s $ Al s
(1) = $ s 3
S
c a a
3 e 5 s N s S a - 3 = s s a 5
a s s - 3 S shy
4
0
a s
bdquo tfH
bdquo
3 a
bdquo
s a
e bullfl s i s s a s a
3 nt
s s 3
g laquo s3 a
~ J s 2 a s o s S s 3 a a j laquo s o s
3 bull laquobull
2 a 7 3 a 3 a ^2
s mdash 5i o
bull bull
mdash
3 o
ss a
fc mdash
3 1-sect m ishy n
18
in both directions to provide a check and permit accurate estimates
of the depth to bedrockThe seismic results allow approximate
interpretations of the depth to the water table and bedrocK thus
permitting an estimation of the saturated thickness Ground
elevations at the location of the seismic surveys were determined
from a topographical map and field siting From this information
water table ana bedrock elevations estimates were made Bedrock
contours are listed in Fig 8 In addition a table which
summarizes the seismic refraction results for the unsaturated
saturated and bedrock layers velocities and depths at each survey
location is presented in Table 2
Scream gauging stations were established on the two streams
bordering the west landfill (Fig 9) Three stations were placed on
the central stream These provide information on the influent or
effluent condition of ground-water flow in the upper sections of the
stream and ground-water baseflow from an area adjacent to the
landfill into the stream (Table 3)
The stream gauging stations used were 90deg V-notch weirs The
weirs located in the SE and SW positions were placed in the
streamoea with a liner of plastic upstream to minimize underflow
The weirs located in the NW and E positions were cut to fit in
recesses of concrete culvert pipes Concrete plywooa interfaces
were coated with roofing cement to minimize bypass flow Upstream
water pressure and a snug fit hold the plywood sections in place
All weirs were implaceo according to AigtTM reouirements and flowrates
calculated using the standard 90deg V-notch formula (3)
19
N
seepage West observat ion Landfill hole
Area
Legend landfill limit excavat ion limit
copyWNWNEECSESC monitoring well locations
= = = unimproved road -- WNES-number
seismic refraction locations
-40shy approximate bedrock contpur elevation
feet
Fig8 Seismte Survey Location
20
c ^-^ c4j ^laquoc in -=r 3shyjj bull pn f- 4-gt bull in in OjJ bull bull a jo bull bull O JJ
co CM o on on CO CM CTNVO VO co CM o on on Q gt_x rH oj on a oj on a - rH oner
rmdash on sr i i
M z Z
gt gt gt
X-N CO laquomdashv CO CO bull igt gt bull
1 gt fc^gtgt bullbull ^ ^ ^
C 4-gt O t igt O J- 4J O H m o o o 3 bullH CO O rH in 3 bullH co vo o in 3 ~ 1 i-k -i ^trade fj rj ui ij o CO o n o rH =r co o n vo vo vo co o bullv O O O
O raquo On-3 rH O -bull- rH ON in _ IH in oj - rH bull rH VO OrH bull rH On ON pH d)u CO -UCO 4J OJ CO 4-gt gt
C mdashbull gt CM gt CM H-l O CO
v- ^^ N C 0
bull0 N CO
4-5 -0 _c^gt in in CO CO
C x~ c -^ t-oo in i 4J j_gt 41 4J bull 9 bull bull 4J bull
o j ON O O 3 (0 O4J O ON ON QJJ t~-^3- OJ 4-gt L
CO CM trade CO CM rH rH OJ co CM oj on Q ^ _ CO 3~Q-- n 45 Q mdash OJ OJ OJ C (0
1 11 3 nZ 2CO
gti gt gt CO CO CO ^-x m -s CO
rH rH ^ ro^^ bull gt bull ^ igt gt bullgt gtgt bull r O -Q 4Ji JJ O 5- JJ O pound- ^ O 4) oj o on (0 CO
3 bullH CJ O O in 3 bullH CO Cmdash VO on 3 pound-laquo H CO o n in inco co o n ma- r co g^ 5sect^ o
o rH on oj O bull- rH ONCO L O_ rH OJ VO M
rH bull rH =t rH bull - OJ T CO CO M CO 4-gt rH CO -U rH CO 4-) s
uits
CO 4-gt 4-5 T3 gt CM gt CM gt CM cc CO CO CO
3 3gt oa tlp^ CO O CM O gt 4J O 40 i 3 r+ k C pound JS
CO pound
^^ s -bullgt cmdash on poundZ VO CTI trx 4J 4J 4J
) bull bull bull Q Q Q Q4J 3shyc O-JJ CTgt OJ OJ Q-IJ inco on CO CO CO o co CM oj on co CM oj on co CM on
Q Q QON^ Q bullH Q^
rH rH 4J rH
O bullraquo L Z bull CO CO CO
i gtgt rH oj on gt tgtshyCM ^ cO^-s CO ~ CO
CO CO J X fc^_ bull^gt bullgtgt bull gt gtgt bull gt CO
j_ jJ O pound- Jj -P O Li deg =fObullH co on f- ^ 3bullH CO CO O in 3bullH CO
g^ -^2
poundsect HO
eis
mic
3 CO in in in in in in co o n co o n
o -^ r oj in O rHCO CO rH bullrH bull rH =T OrH bull rH OJ f-CO 4J bull- CO 4J rH O0) J-)
gt CM gt CM gt CM 4J
CO N_^ m^
bull OJ
t t poundshyCO CO CO CO rH J3 gt r-t oj on gt r-i oj on gt gt r n o j o n
lto co lto CO T bull ii-4 laquomdash bullmdashH
bullo CO L L 0)
CM CO cc
21
N
545-594
seepage observation
hole West Landfill
0NE I47-509
Area
Weir 45
i487-531
0 EC Al3-467
Legend bullmdash landfill limit -bull---excavation limit r-s stream
copy WNWNEECSESCSEN monitoring well locations
= = = unimproved road
Weir location and elevation
feet
Fig 9 Weir Locations and Wate r Level Ranges
22
JT NO
S shy S
O
bull ry m
oa
NO
(M raquo 1 03 or NO m
JT O O raquo
O NO 03 (j
PW tn in ^4 fraquo
m CN) f O O (M Oj
mdashraquo 3 M
s cshy -raquoraquo
o in in ^
rjO
laquobull NO ON
o bull-lt ^
H fy (NJ
tjgt
1 4 03 O
o
o
03 CM
in0
0
7 raquo
9gt
IM i iev NO
i in
i ru
i 0 rsi -or^
sO NO
CO O
03 raquo
1 O3
pound o ro CNJ
03
tn B OJ
o 03
m oi
NO
(M
r
(M
CO i M 03
m N ltn ~+ ltM -
QJrH
O M O ^ ^r-
oo m
8 a
m
^ NO
8 fNl
rshy03n
m - in
o laquoO
bull3 as m o 03 03 4
i O
i ^
shy
O
ltM bull^
ON f tn H 1 4 raquo4 i-4 H P-t
^^ lt-l
r-laquo
^ 1 1 1 1
pound raquoraquo O)t o gtz
bull bull ltbull
lt2
1 pound OJ
3 oi g bull
pound
1 pound laquolt bull
3 bull o a
pound
5 laquo15
f bull 3 Jl s
5bull 1 5
23
A field study to determine the infiltration capacity of a
section of tne landfill topcover was conaucted A modified version
of a double ring infiltrometer was used to study infiltration rates
(4) The cylinder diameters useo in this study were 8 inches and 18
inches A constant head of 6 in was maintained in the
infiltrometer and rates of infiltration were determined Tnese
results and an analysis of surface infiltration into the landfill
are included in tne analysis and discussion section
Specific conductance levels in the monitoring wells in the
streams bordering the landfill and at observation holes near the
landfill were measured (Fig 10) This is a good indication of the
mineralization of water (39) Specific conductances were measured
intermittently over the ten month period to develop a picture of the
extent and degree of contamination in the wells (Fig 11 Taole4j
and in the surface contamination monitoring locations (Fig 11
Table 5) A comparative standardization of the Beckman (short and
long probes) and YSI specific conductances is in Appendix C
A surface electrical sounding using the Schlumberger array was
conducted adjacent to Rose Hill Road at the R-l location (Fig 12)
in an attempt to delineate the vertical extent of the contamination
zone Well W was used as a centerpoint and a reference for
water-table depth pore water conductivity and depth to bedrock A
Schlumberger array electrical resistivity sounding was also
conducted in an uncontaminated area at tne R-2 location (Fig 12) to
provide a comparison background interpretation A seismic
refraction survey N-4 was conducted at the same location (Fig 8J to
24
N
excavat ion
Seepage West observat ion Landfill hole
Area
Stream 1 Seasonal observation 0 EC
hole
East Stream2
Legend sw Weir landfill limit j--1--^ excavation limit
copyWNWNEECSESC monitoring well locations
== unimproved road
feet
Fig 10 Surface Contamination Monitoring Locations
25
8000T
7000
O bull U) W6000
Legend
0 sc A NE O W
A SE O N W
a EC
1 O N D J F M M
Time months Flg11 Flucuatlon In Specific Conductance in Wells
26
Table 4 Specific Conductances in Wells (pmhoscm at 25degC)
West East Landfill Landfill
Date NW NE EG SE W SC N E S
81581 851 938 236 2356
102981 171 3268
11381 3268
111081 304 988 1100 258 3800
111481 426 2736 1216 186 4560
111781 304 3610 433 389 4560
121981 380 1406 129 103 380
1982 160 152
31582 274 760 1064 61 334 8000+ 182 53 84
52182 450 1500 1125 112 712 8000+ 175 255 150
52282 425 1320 1200 110 850 180 320 170
27
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28
excavation
West Landfill
Area
Legend bullmdash landfill limit -bullbull--bullexcavation limit r~~s stream
copy WNWNEECSESCSEN monitoring well locations
= == unimproved road
electrical resistivity sounding
feet Fig12 Electrical Resistivity Sounding Location
L
29
allow estimates of depth to water table and bedrocic to be made
Soundings were carried out to 500 foot electrode spacings to insure
that hredrock was penetrated and to facilitate interpretation These
results and a discussion of the soundings interpretation are
included in the analysis and discussion section Schlumoerger
resistivity soundings were made using a Soiltest R-bO unit
30
Model Development
The USGS Iterative Digital Model for Aauifer Evaluation was
usea to develop steady state flow models of the study area (43) A
flow chart of the computer model and a brief explanation of the
subroutines usea is presented in Appendix D The stream locations
elevations and aauiferlandfil1 geometry and hydraulic properties
were input to the model to compute head values at each 200 foot
grid spacing node (Fig 13) The input data which is for the
existing excavation and landfill conditon is listed in Appendix E
The head values that are computed at each grid space are in turn
loaded into the CalComp plotting routine (44) where a grid spacing
is setup with the computed head values at each node The contouring
program linearly interpolates between these head values and
generates a contour map The computer simulated ground-water
contour map for the excavation and landfill is presented in Fig
14
The streams in the model generally serve as controlling boundary
conditions When using computer simulated geohydrologic models of
an area choosing the boundary conditions for the model that are the
same as prevailing conditions in the field is a critical step in
model development Extending the models boundaries to areas in the
field that have a minimum influx of ground-water across them
simplifies the proolem of calculating fluxes from outside the model
area The eastern boundary is bordered by glacial till which has a
low hydraulic conductivity estimated to be 67 ftday(2) This
contrasts to the high hydraulic conductivity of glacial outwash that
makes up the model area of approximately 107 ftday(3036j
31 N
o 9
bullO O
32
33
The Saugatucket River serves as the controlling boundary on the
east A small drainage area directly to the east of it provides a
minimal influx
Beyond the moaels northern boundary the glacial outwash valley
extends to the base of a till covered h i l l on the western half ana
on the eastern side extends along the Saugatucket stream Due to
the relatively large drainage area that lies upgradient from the
northern boundary a recharge flux eduivalent to 10 inyr over the
drainage area on the till hill and outwash area north of the model
area was input as underflow (Fig Ib) Part of this was input at
each northern boundary node Till has a lower infiltration capacity
than outwash so more of the precipitation w i l l be transmitted as
overland runoff resulting in a lower ground-water baseflow The 10
inyr of recharge that results in a ground-water inflow from the
combined till and outwash region represents an estimate that is
smaller than the 14 inyr recharge for glacial outwash areas in
Rhode Island (25)
The glacial outwash valley extends beyond the western boundary
No significant ground-water recharge flux was estimated at this
boundary A relatively low ground-water gradient exists to the west
of this which does not provide a significant flux across this
boundary Tne southern boundary is basically the outflow region for
the area and therefore would not reauire any ground-water flux into
the moael area across this boundary This boundary was set south of
the point that the streams in the model merge together Therefore
the streams which lie to the north of it are the controlling
34
scale 124000
Fig 15 Northern Drainage Area
35
boundary conditions The flux out of the downgradient outflow
region approximately eauals the influx from precipitation recharge
and boundary influxes
When tne stream configuration in the moael area are reviewed it
can be seen that they comprise a large portion of the boundary
area The screams can act as sources or sinks for water in the
model thus providing to and removing water from the aquifer The
leakance option was used in the model which provides for a confining
bed and aouifer area beneath the stream to be input
The leakance is defined as the hydraulic conductance of the
streambed divided by the streambed thickness which in this case is
taken as 1 foot The leakance value at each streambed node
restricts the flow between the aduifer and the stream The
streambed hydraulic conductivity is typically 01 the value of tne
hydraulic conductivity of the aduifer (717) The value 107
ftday was used for a streambed conductivity based on a value of
107 ftday for the aquifer The aduifer and stream hydraulic
inputoutput exchange at eacn node is calculated by initially
finding the difference between the initial field stream head
elevations and the computed head elevation values at the
corresponding nodes This head value is then multiplied by the
(Leakance value at each node) x (stream area of each node)
Therefore if the aduifer head was lower than the stream head the
stream would act as a source of water for the aquifer and vice
versa
36
Tne leaxance input at each stream node is the ratio of the
actual field streambed area in each node to the area of each node
which is 200 ft x 200 ft = 4 x 104 ft2 The west
excavations stream width is approximately 3 ft central 4 ft and
east 5 ft Therefore if tne west stream traverses the node
directly without meandering it presents a leakance of 3 ft x 200
ft4 x 104 ft = 015 Leakance and streamhead values were
input at each node to set up the stream flow parameters in the
models
A recharge value of 14 inyr over the entire area was input at
each node This represents a value of precipitation that is
transmuted into tne ground-water rather than being directly
evaporated evapotranspired through plants or overland flow
runoff The precipitation recharge flow from the stream into the
aauifer and boundary fluxes provide the model witn input flow
parameters
From analyzing the available information it was determined that
the study area lies within a glacial outwash area with a relatively
shallow bedrock The seismic survey around the landfill generally
indicates a depth to bedrock below the land surface of approximately
29-43 ft with corresponding saturated thicknesses of 19-33 ft as
seen in Table 2 This agrees with borings from tne USGS groundwater
map in the stuuy area (18j The seismic survey was run at a low
water table condition which was several feet below the high water
table level (Fig 9)
37
High water-table saturated thicknesses were used to develop
model parameters For the purpose of this model study the saturated
thickness was set at 30 ft except in the vicinity of well W where
there is a bedrock high (Fig 8) At this location a high water
table saturateo tnicxness of 8 ft was estimated In tne vicinity
the seismic survey was conducted the bedrock elevation at this
location is the highest and the saturated thickness the least Tnis
can be seen by an east-west cross section of tne landfill (Fig 16
The boring log for well W indicates a sand trace gravel outwash
material (Appendix B) Boring logs at the eastern landfill area N
and E indicate similar material On this basis the hydraulic
conductivity was estimated at 107 ftday (3036) Witn the
exception of the landfill and the bedrock hign areas the
transmissivity values were set at 107 ftday x 30 ft = 3210
fto day From the literature the hydraulic conductivity of the
landfill material was estimated at I ftday (19) The
transmissivity of the landfill material in tne nortnern section was
estimatea at 1 ftday x 30 ft = 30 ft^day or approximately two
orders of magnitude lower than the outwash In tne landfills
southern section the original excavation was not as deep as in the
northern parts The landfill material was estimated to makeup only
one half tne saturated depth the remainder being the original
glacial outwash material (Fig 17) Therefore the transmissivity
at the southern end was estimated at 15 ft x 107 ftday + lb ft x
1 ftday = 1620 ft^day These values were graded into the 30
ft^day values at the landfills northern halfway point These
38
were input as transmissivity values to the model at their respective
locations This model did not use the water taole option so
water-table fluctuations did not affect the transmissivities
39
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Model Calibration
A simulation was run using the initial estimates of stream
parameters aquifer and landfill hydraulic conductivities
transmissivities boundary and recharge conditions to approximate
water taole conditions in tne fiela Initially the existing
condition of the excavation area to tne west of Rose Hill Road and
the landfill to tne east were modeled in order to calibrate the
model to current field conditions as shown on Fig 4 The simulated
well values (Fig 14) fall within tne range of field values (Fig
9) The resulting contours also provide an approximate matcn This
can be seen by comparing Fig 4 with Fig 14 An additional check
was to match the flow loss and gain in the streams between tne weirs
in the central stream which w i l l be discussed later The
simulated flow value from the excavation drainage stream is the same
as that measured at the SW weir location Having calibrated the
model by approximately matching well water levels nead contours
and scream flow values different field conditions and possible
remedial measures can be simulated
When the model grid was laid out over the study area as viewed on
Fig 13 the stream configuration rarely traversed the grid nodes near
their central axis When the stream locations were input to the
computer the information was documented as crossing the central axis
of the grid nodes The result of this is a slight aberration when
the actual stream configuration is laid over the computer graphics
head contour output The streams dont always cross the groundshy
water contour at the logical location Rather than modifying the
actual stream configuration to adjust then to the computer output
their actual locations are presented
42
Simulations
i The primary focus of the computer modeling is to analyze flow
patterns under changing conaitions in the near vicinity of tne raquo
landfill The study areas overall flow patterns as they exist
today are first presented in order to realize the lateral east-west
head contour lines between the stream that directly borders the
landfill on the east side and the SaugatucKet stream (Fig 14)
This indicates a general southerly flow direction in that area As
different conditions are modeled these contours generally maintain
their east-west orientation In order to facilitate interpretation
of flow patterns in the near vicinity of the landfill flow patterns
to the west of the stream that borders the east side of the landfill
r are presented in the subseauent models
L- Natural Conditions
The results of modeling the original natural conditions are
shown in Fig 18 The excavation and stream to tne west of Rose
Hill Road and tne landfill did not exist in this simulation The
southwestern boundary consists of a drainage stream that was
delineated using an aerial photograph and stream elevations were set
using the topographical map The USGS ground-water map (18) was
used to estimate head values between the west excavation and north
streams These were input to the model as constant heads on the
models western boundary The resulting simulation generally matches
the southeasterly flow direction that is indicated on the
ground-water map (Fig 5)
A3
Legend
x-^- stream 400 = = = unimproved road
I f ee t
Fig 18 Natural Conditions
44
Excavation Without Landfill
The condition of the excavation to the west of Rose Hill Road
with its resultant drainage stream without the landfill was modeled
next (Fig 19) The extent of the excavation ana the location of
the new drainage stream were delineated using the aerial
photograph The west stream elevations were sited in the field and
used in the model The concept of a confining streamoed layer was
excluded in tne excavation drainage stream under the concept tnat no
significant organic layer had been built up within the 25 year
period that the excavation had been initiated Head values between
the west and north stream boundaries were interpolated and input as
constant head values on the northwestern boundary The west
excavation drainage stream creates a condition that alters the
natural ground-water flow patterns by creating a more southerly flow
condition the drainage stream providing a more immediate surface
outflow in that area
Landfill Without Excavation
The hypothetical case of a landfill without the excavation was
modeled next (Fig 20) The low hydraulic conductivity zone of the
landfill changes the natural flow conditions and creates noticeable
mounding This is evidenced by the decreased spacing of the head
contour lines and deviation from the lateral contour lines of the
natural conditions and higher head values (Fig 21)
45
Legend
excava t i on s t ream
400 unimproved road
f e e t
Fig19 Excavat ion without Landfill
46
Legend
landfill limit
bull - s t ream 400 copy WNWNEECSESC
monitoring well locations f ee t bullbull-bull=bull unimproved road
Fig 20 Landfill without Excavation
1
oin CM
bull
m u
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bullo 9
bullo 9
o rf o o CO 1
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47
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48
Landfill ana Excavation
The condition of tne existing landfill and the excavation with
the dam is the next condition modeled (Fig 22) The ground-water
elevations used to calibrate tne model correspond to an actual high
water table condition Between the NVJ and pound weir a streamflow loss
of approximately 102 gpm occurs aoout 60 percent of this flow is
lost at the dam site which maintains a head of b-6 feet over an area
of approximately 1800 feet^ This approximates a field value of
1144 gpm influent to the aduifer between the NW and E weir on ]2
December 1981 (Table 3) From the E weir to the SE weir a net
increase in flow occurred of 74 gpm which corresponds to field
increase of b62 gpm
The surface runoff from tne landfill flows primarily toward tne
eastern side of the landfill Increases in water-table elevations
on the eastern side after heavy rains such as the 11 November 1981
storm indicates that this runoff increases outflow gradients to the
stream and therefore increases streamflow Surface runoff input is
not modeled which explains in part why field stream inflow values
are slightly higher than model predictions especially for periods
after a storm has occurred The flow from the SW weir located at
the southern end of the excavation represents drainage outflows from
that area The net flow calculated in the model was 140 gpm
which approximates field conditions of 1642 gpm on
December 9 1981
49
d f l f reg N E
shy
Legend
landfill limit -bullgt-bullgt- excavation ^-N_X- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road
-40mdash approximate groundwater contour
400
feet
Fig 22 Landfill and Excavation with Dam
50
The modeled flow patterns suggest how the various contamination
zones around the landfill have developed to their present state
They indicate a flow to both the southeast and southwest on their
respective sides of the groundwater divide Evidence of a
southwesterly contaminant flow is presented when the continued high
specific conductance contaminant level in tne observation seepage
hole is realized (Table 5 ) In addition the specific conductance
increase in the west excavation stream is evidence of an influent
contamination flow
Contamination flow to the eastern and southeastern side of the
landfill is obvious High specific conductance levels in the wells
on the eastern side (Table 4 ) a specific conductance increase
between the E and SE weirs (Table 5 ) and contamination in the NE
domestic supply well (Fig 3) present conclusive evidence of
contamination to the eastern side of the landfill
An anamalous condition that exists is a domestic supply well
located approximately 300 feet due south of the landfill remains
uncontaminated (Fig 3) Flow patterns indicate that contamination
would be transported from the landfill south to this area
(Fig 14) One explanation is that a pocket of clay at the southern
end of the landfill area was discovered in the original excavation
for the landfill (lt6) This evidently prevents leachate from
reaching this wells radius of influence
51
Summer Conaitlon
As described earlier during dry months of the year the stream
that normally borders the northern and eastern side of the lanafill
may dry up as far as a point southeast of the E well Tnis
condition existed from the 15 August 1981 to the 27 October 1981
period when streamflow commenced in the northern part of the stream
yet did not overflow the north dam until 17 November 1981 This
created the present day continuous flow condition throughout the
stream These summer conditions were modeled by removing the stream
above the aforementioned location while other conditions remained
the same (Fig 23) Summer condition well water levels listed in the
model generally match field low water table conditions (Fig 9)
Because there is no stream upgradient from the landfill to provide a
stream head and infiltration through the streambed groundwater
runoff from the area north of the lanafill is the controlling flow
input In these moaels an average recharge of 14 inyr was used
which represents a yearly average The summer recnarge conditions
are prooably lower given the effects of decreased rainfall and
increased evapotranspiration during the summer months A domestic
supply well whicn exists northeast of the landfill (Fig 3) nas a
greater potential to be contaminated from the lanafill at tnis time
than when the stream is flowing Flow patterns from the landfill
are such that during an upper stream no-flow condition groundwater
flow patterns are more in an easterly direction than in a
southeasterly direction The stream would act as a source of
infiltrated water upgradient from tne landfill and provide a
52
I ^N gt i I i j i -r- -bull- bullr -T- t- -r- i- TJ JV
bullbullT laquo ^ O - laquo bdquo xi cshy
H r^~ I -~- --^ X- = mdash x^ N
^--^ A bull O^NW -v - gt-bull Ni i I _____mdash - bull laquo l - mdashmdash 1 deg I ^ltv I C
I reg NE A
Js bull vbull A ~ - v T gt- ^ ix - N
-5Z- | N TfS lV I -bull bull iA i gt gt I ^ bullr-Ky L bull 1 _- copy]wgt-- - bull- mdash - - shy
= r Y ~mdash ltmdashA A
^^-lt A _ - - - - bull Hmdash - reg EC x ^-mdash mdash I ---mdash_mdash -t-V-^N - y
I- -bull - r x i X
V ^ 7 I -v (^~~^^r ^^^
sc Emdash-bull vV JI - - - ~ r )N y- -
X - bull r bulllt
^bull^ y y Jlaquo^ - -lt shy
T s^ lt^ ^ +^-b (
X
Legend
landfill limit j-j-bullraquobull excavat ion gt^ -x- s t ream
reg WNWNEECSESC monitoring well locat ions
= == unimproved road fee t
Fig 23 Summer Condition
400
53
constant head across tne northern section of the landfill This
would tend to orient the flow in a more southerly aowngradient
direction In addition the stream which flows adjacent to the
northeastern well could provide a source of infiltrated clean water
to it which would minimize the possible contamination from landfill
leachate
Without Dam
During tne spring scream flow condition the dam failure which
occurred between the 15 March 1982 ana 9 April 1982 monitoring
periods decreased flow to the aauifer and landfill This eliminated
the 5-6 foot head difference over a 19000 ft^ area which had
created a larger area and elevation head for infiltration to occur
The condition without the dam was modeled by reducing the area
encompassed by the dam to a 4 foot wide stream channel thus
reducing the leakance value at that node (Fig 24) The flow change
from the stream to the aduifer between the NW weir and E weir
reduced the model flow loss to 50 gpm Tnis corresponds to the 9
April 1982 monitoring period which indicates a 30 gpm loss
As compared to the previous flow loss in the upper stream
sections to the aauifer the 21 April 1982 and 22 May 1982
measurements between the NW and E weirs indicate a flow gain The
streamflow conditions have changed from an influent
stream-to-aauifer condition to an effluent aduifer-to-stream
condition that increases flow downstream
54
Legend
landfill limit j--i--i- excava t ion x-gtmdash^- stream 400
copy WNWNEECSESC monitoring well locations
= == unimproved road f e e t
Fig 24 Landfill and Excavation without Dam
55
Analysis and Discussion
In order to fully understand flow patterns and Quantify leachate
outflows at the landfill it is necessary to arrive at an estimate
of flow inputs from precipitation ana upgradient sources In the
following analysis it will be demonstrated that the rainfall input
to the landfill is the factor which controls leachate generation A
calculation using the H inyr recharge over the area of the
landfill was made to estimate the leachate outflow due to rainfall
infiltration An estimated 134 gpm is generated from the entire
landfill area Simulation of the existing conditions (Fig 24)
indicates a groundwater divide in the landfill is located
approximately at the western third Therefore approximately 23 of
the generated leachate flows to the eastern side of the landfill or
9 gpm The effect of the flow input from the upgradient stream is
evident when tne summer condition witnout the stream is viewed
(Fig 23) Without the stream to infiltrate the landfill and the
recharge and northern boundary condition as the flow inputs the
head at the northern end of the landfill drops about 5 feet from its
previous value A flow pattern from the north central part of the
landfill to the eastern side indicates a 12 feet head difference
with recharge - but with the upgradient stream a 16 foot head
difference occurs Considering the transmissivity change the
stream would increase the leacnate outflow from the landfill
approximately 43 under a low water table stream influent condition
to the aauifer This would increase leachate outflow to the east
side to approximately 129 gpm This value approximates the
56
outflow at the SE weir location during the summer monitoring period
when the upper stream was not flowing (Table 3) The outflow from
the western third of the landfill whicn lies to the west of the
ground-water divide would be approximately 63 gpm
Realizing the importance of infiltration to tne landfill as a
major influence on the generation of leachate an analysis of this
w i ll be discussed An estimate of infiltration was made using the
precipitation recora for October ana November (Appendix A) During
this time period a minimum of direct evaporation ana
evapotranspiration occured and the grouna is not yet frozen The
top cover over the lanafill is generally 05 ft to 2 ft of local
sandy soil and subsoil availability determined what was used The
top of the landfill is at an elevation of 92 ft as compared to the
ground surface at well W which is at an elevation of 76 ft
(Fig 25) This compares to the well W water level which is at an
elevation of approximately 52 ft This creates a long path for
infiltration through the unsaturated zone The topcover generally
slopes eastwara at a grade of 2-5 The west side maintains a
relatively steep slope of 10-15 ft drop within 50 ft ana the north
and eastern slopes have a more gentle slope of approximately 10 ft
within 100 ft distance An unlined surface arainage swale channels
surface runoff from the northern section of the landfill past the
NE well to the eastern side ana low area in the vicinity of the E
well This has a drainage swale to an area near the stream but
doesnt directly connect to tne stream A poorly graaed drainage
swale exists on the landfills left side The landfill material has
57
excavation
seepage observation ^
hole
Legend bullmdash landfill limit -^--excavation limit r^s- stream
copy WNWNEECSeSCSEN monitoring well locations
--- unimproved road O location of amp Inf i l t rometers O
feet
Fig 25 Infi ltrometer Locat ion and Drainage Feature
58
been placed in 10-12 ft cells and covered with 1 ft of soil at the
end of each day The material has settled differentially creating
areas for depression storage
An estimate of the percentage of precipitation that infiltrates
the landfill was made from precipitation records recorded well
elevations and an estimated specific yield for the landfill
material The volume of water that infiltrated should eaual tne
specific yield multiplied by the well water level rise Several
recharge periods were studied using this relationship Once the
percentage of precipitation that has infiltrated is determined the
percentage that is translated into runoff is simply the remaining
percentage if evaporation is neglected
From the literature for a slightly inclined slope of 2-5
typical runoff coefficients range from 10-20 in either sandy or
heavy soil (16) The landfill cover is generally sloping to the
east which creates a long path (approximately 400 ft) before the
runoff reaches the steeper slope on the eastern side of the landfill
of 15-20 The long drainage distance creates a greater time for
rainfall to infiltrate Another consideration is the actual
capacity of the soil to conauct water into the soil which was tested
in the field using double ring infiltrometers An average initial
percolation of 8 mmhr the first hour and a subseauent rate of b
mmhr occurred (Fig 26) The 8 mmhr rate compares well with
other sandy soil infiltration rates (14) Therefore if the
intensity of the rainfall exceeded a 5 mmhr rate for several hours
59
CO + 09 o
E o
CO
o Z pound C
O
C9
o DC
CO
CD CM
ogt CO N- to -4 CO CM
jq tuu i U O | raquo B J J | | J U |
60
on a poorly drained surface the additional rainfall would be
translated into runoff because the soils infiltration capacity had
been exceeded
The initial 8 mmhr infiltration rate was due to the pore spaces
in the sandy soil being filled and the subsequent 5 mmhr rate was
percolation into the low permeability landfill material The tests
were conducted in November assuming a minimal evapotranspiration
and the field capacity of the sandy soil had been maintainea
The W well was used as representative of the water elevation
changes in the landfill because it is directly adjacent to the
landfill 900 ft distant from the upgradient stream This minimizes
the effect of infiltration from the stream and maintains a high
contaminant level During periods of high runoff conditions excess
surface water ponded in a poorly graded drainage swale on the west
side and directly adjacent to the landfill This influenced the W
well at a time the contamination level dropped (Fig 11) Before
this occurence in mid-December the rise of the W well closely
matches that of the SC well and a background well SK6 which is
located outside the study area (Fig 7) Therefore it was analyzed
as a valia indication of the water level rise during the mid-October
to mid-December period The monitoring of the SC well was
intermittent due to inaccessaoility because of 10 ft extensions
being placed on the well as the refuse was being filled in arouna it
61
A high rainfall period from 14 November 1981 to 1 December 1981
was chosen for the initial study period The effects of
evapotranspiration were neglected due to the cool temperatures
experienced at this time Therefore it was assumed that the field
capacity haa been reachea and tnat any additional input to tne
unsaturated zone would result in direct percolation to tne saturated
zone During the time period 14 November 1981 to 22 November 1981
029 ft of rainfall fell and the well W rose from 488 ft to 493
ft - a 05 ft increase During the next 8 day period there was no
precipitation yet the W well continued to rise to 4972 - a 042 ft
increase The slow percolation of water through the landfill
material would account for the latent rise in the well water level
From previous reports a specific yield for refuse was estimated to
be 028 (1920) This value is dependent on the original compaction
of tne material age and resulting consolidation
During the 14 November 1981 to 1 December 1981 period 029 ft
of rain fell and the well increased 092 ft The following
relationship is used to evaluate the infiltration value and runoff
I = (Sy) h
Sy = specific yield
h = well rise
I = volume infiltrated
I = (028) (092 ft) = 0261 ft
62
The difference between the precipitation and the infiltration is
the runoff (assuming no evapotranspiration) Therefore 029 - 026 =
003 and furthermore 003029 - 13 runoff This corresponds in
the literature to a typical runoff coefficient for an inclined
surface of 2-5
Analyzing a longer precipitation period from 18 October 1981 to
1 December 1981 a net precipitation of 043 ft (accounts for
evaporation) occurred less 10 for runoff or 039 ft infiltrated
This results in a 139 ft elevation increase The well water level
actually increased 132 ft shy only a 5 deviation from the
calculated
From tnis investigation it is seen that a large proportion of
the precipitation has the potential to be transmitted into the
landfills saturated zone Exceptions are wnen heavy precipitation
periods exceed the soil percolation capacity frozen ground prevents
infiltration and direct evaporation and evapotranspiration recycles
the ponded surface water and infiltrated soil moisture back to the
atmosphere In retrospect water temperatures within the monitoring
wells could have been measured to indicate thermal effects from the
landfill on ground-water temperature Ground-water temperatures
were assumed to be 50deg F (9)
63
Specific conductance measurements serve as an indication of
contamination levels These measurements are used to trace leachate
movement which represents ground-water flow patterns Factors which
must be considered when monitoring pollutants are the attenuation of
the leachate contaminants which occurs both in the zone of aeration
and the saturated zone The former is a more complete process
Dilution dispersion and cation exchange are the primary factors
involved in decreasing leachate concentration in the saturated
zone The glacial outwash materials of southern Rhode Island do not
have a cation exchange capacity or a high buffering capacity so
attenuation is simply by dilution and dispersion (22)
The NW well consistently exhibits relatively low specific
conductance levels even though it is in landfill material It is
situated in a drainage swale and ground water elevations range from
543 to 5944 This is several feet below the upgradient stream
elevation of 64 feet which is less than 400 feet away The bottom
of the wellpoint is at an elevation of 5312 feet well into the
landfill material Infiltration from the stream to the landfill has
occurred at this location
The W well is situated on a bedrock high adjacent to the
landfill approximately 900 feet from the upgradient stream and its
water level is higher in elevation than the excavated pit (West
Observation Hole) which is 300 feet directly west The W well
maintains a contaminated level A poorly graded drainage swale to
the west of the landfill provides areas for extensive ponding and
infiltration to occur which explains the drop in conductance after
a high runoff period
64
The SC well is located in landfill material and has a
conductance of over 8000 umhos This indicates that leachate is
undiluted The oottom of the wellpoint is at an elevation of 389
feet which is situated in the landfill material
High specific conductance measurements in the west observation
hole and well W and their relative elevations indicate a
west-southwesterly flow direction from the landfill Infiltration
recharge and leakance from the stream into the landfill provides the
necessary elevation to cause outflow in this direction
Contamination from the landfill to the surrounding streams is
evident (Table 4) During the period 15 August 1981 to 27 Octooer
1981 there was no flow in the stream that Borders the northern and
eastern side of the landfill until a point just south of the E well
was reached High specific conductance levels in the EC and NE
wells were recorded (1000 jjmnos) At a point directly east of well
EC a pool of water existed that was relatively uncontaminated which
is designated as the East Stream] location (Fig 10) At a point
just south of that (East Stream^ polluted water in the streambed
was flowing at a low rate This was measured at the SE weir
location and which had a high conductance also Flowrates varied
between 6 and 23 gpm and specific conductances were over 350
pmhos This low water table condition flowrate is the baseflow from
the eastern side of the landfill and indicates a southeasterly flow
direction from it
Streamflow commenced in tne northern part of the stream 21
October 1931 and the north dam oegan to f i l l Stream specific
65
conductances were low indicating a clean water source Tnis
continued until 17 November 1981 when the dam overflowed ana flow
throughout the east stream began A weir was placed at the Rose
Hill Road NW location and was compared to flowrates at the SE
location Flowrates decreased and specific conductances increased
between these two locations
To further investigate the condition of a lower flowrate
downstream than upstream an intermediate weir was placed at the E
weir location (Fig 9) This snowed tnat the stream from the M
weir to the E weir was losing water to the aauifer (influent
condition) and gaining water at the SE weir (effluent condition)
The condition of a net loss of water between the NW and SE weirs
remained until 19 December 1981 when a snowmelt rain condition
caused increased surface runoff and a net increase in flow at the SE
location Upon analyzing the March and April 1982 streamflow
conditions the expected case of a net ground-water pickup from the
E to SE weir continued The explanation for tne initial net loss of
ground-water is the fact that the leakance from the upstream section
was being discharged into aauifer storage to raise the ground-water
table to an eduilibrium level Upon reaching a high recharge
equilibrium steady state condition any additional input will
eventually be transmitted as baseflow out of the landfill and a
downstream net pickup will occur A hign water table condition
prevailed during the January through May period maintaining this
condition In April the north dam broke through reducing the head
in that area by 4-6 feet The 9 April 1982 monitoring revealed that
66
an influent condition remained between the NW and E weirs but at a
reduced rate The 21 April lower stream flow condition shows a
small pickup of water between the NW and E weirs indicating the nigh
water table and low stream flow conaitions combined with the absence
of the dam had changed the conditions to an effluent condition
This was evident in the May monitoring period
Evidence of contamination on both the western and eastern sides
of the landfill supports the existence of a ground-water divide in
the landfill The west stream which drains the excavated area to
the west of Rose Hill Road shows contamination pickup between its
northern section and the SW weir The W well and ooservation hole
indicate high contamination levels which reinforces the concept of a
contaminant outflow to tne west excavation stream
As shown previously flow towara the eastern side of the
landfill is evident from the nign specific conductances and specific
conductances increases in the stream This is especially evident
during low flow conditions when the stream starts at a point to the
east of the landfill and flows with high specific conductance levels
From the literature a relationship between specific conductance
and dissolved solids exists the dissolved solids (mg1) are
approximately equal to the specific conductance times a factor
ranging between 55 and 09 (39) in this case it is taken as
065 (41) The dissolved solids increase coupled with the stream
flow increases provides a basis of calculating the dissolved solids
outflow to tne stream This calculation method was used in a
previous study (26)
67
The relationship
=Cinout Coutflow Qoutflow - Cupstream Qupstream Qinput
where the numerator is the streamflow pickup and the C- and
Q-jnput is the concentration and flow input from the ground-water
This can be used to estimate dilution level outflows from the
landfill Initially this is used for the ambient ground-water
pickup between the E weir and the SE weir This entire flow doesnt
come from tne lanafill but much of it is conaucted in the high
transmissivity area between the lanafill and stream from upstream
leaxage ana surficial recharge Tnis is evident when this section
of the flow pattern is analyzed on Fig 22 Therefore the landfill
outflow is mixed with tne ambient groundwater flow which dilutes the
landfill leachate before it enters the stream To illustrate-this
concept a calculation using the 9 December 1981 monitoring is used
At this time a flow of 672 gpm occurred at the SE weir with a
specific conductance increase of 7 ymhos between the E and SE
weirs The dissolved solids increase would be approximately 795
Today in tne stream
Where
Co = 90 jumho at SE weir
Qo = 672 gpm at SE weir
Cus = 83 jumho at E weir
Qus = 606 gpm at E weir
Qinput = 66 gpm gain
Cinput = 154 jumho
68
The 154 jumho value represents the contaminant level in the
ground-water adjacent to the landfill
This relationship is applied to approximate the concentration
level dilution in the ambient ground-water between the landfill and
stream The aforementioned relationsnip is in turn applied to the
landfill outflow into the ambient ground-water flow adjacent to the
landfill The ground-water receives landfill leachate dilutes it
and then transmits it to the stream The previously calculated
value of 129 gpm was used as the outflow from the landfill
Co 154 jumho flows into stream
Qo = 67 gpm flow into stream
Cus = 83 jumho background level
Qus = 67 gpm - 129 gpm = 541 gpm
Qinput = 129 gpm from landfill
Cinput = 451 jumhos
Approximately tne same contaminant levels from the landfill (tbl
umho) are arrived at as existed in the summer streamflow conditions
when the upgradient ground-water flow adjacent to the landfill was
at a minimum
In addition to using specific conductance to define
contamination zones electrical resistivity can be used to indicate
contaminated areas The measured earth resistivity is inversely
proportional to the conductivity of ground-water Water containing
contaminants with high ionic concentrations are more electrically
conductive and will have lower resistivity values than surrounding
natural ground water Therefore resistivity methods can be used to
69
delineate plumes of contaminated ground-water that have hign
specific conductances This has been demonstrated by several
investigations (11122328374045)
In this study a Schlumberger vertical electrical sounding R-l
was made in an area of known contamination at the W well (Fig 12)
Given the geologic constraints provided by the well boring log a 4
layer computer model was used to match field survey values A
Schlumberger sounding R-2 in an uncontaminated area north of the
landfill in the same geologic setting was used to provide a
comparison background sounding (Fig 12) A seismic survey N-4 was
made to obtain water table depth and depth to bedrock as input
parameters to a four layer resistivity model (Fig 8) Tne results
of the electrical soundings have been tabulated in Table 6 and
plotted in Fig 27 and 28 respectively
The ascending portion of the field Schlumberger curves were
initially matched using a two-layer ascending type master curve to
provide an approximate depth and apparent resistivity of the
overburdened topsoil layer (8) Tne second unsaturated layers
apparent resistivity was determined by using the graphical
interpretation of total transverse resistance The total transverse
resistance is approximately eoual to the peak value of the curve
times the corresponding Ab2 distance it occurred at This in turn
is eaual to the sum of the first two layers apparent resistivity
times their corresponding layer depths
70
bullH
OJ bull bullH 4J CO CM
c ce G bullrH
j-gt ca c c a 3 ltu O L
co CO 0
bullo Q bull laquos c n 3 -U OrH f~ 3 bO ltn y CO O cc CO ^mdashN
QQ bull
bO bOJJ C C Ci_i
O l T i O O O O O O O O O O O O O O O O bullH bullH mdash^ bullo 0 C c3 f| 3 O raquo O CO CQ
CO
rH
CO O
L 4J
^ltU
i- 1 ^n ^b O 4-) bull2 CM bullH C OJ 1 -U bullH CO C L O a ^-^ 0) a
rH c a L CD ltu (1) 3 tlt bO cO I
3 a 0) a Q 4J laquoa e CO 3 (H bO c C O bullH
CO TJ C 3 bull
bull O bO -i-3
0 CO C O3- O G O O O O O O O O O O O O O O O O O O ft rt1 -raquo - t l S^ ft tfigt f I mdash^ K_ l_ raquo mdash I gt fgt I l 1
(1) 0 rH CO CJ JD o^^ CO CO CQH lts
71
Legend
A actual field measurement
-e- interpretat ion
10000 bull
6000 bull 5000
4000-
3000shy
pound2000| ltD
_ r 1000
09
5 600 pound 500 - 400
I 300 a a lt 200
100 10
Fig 27
20 30 4050 100
Distance AB2
Schlumberger Sounding
200
feet
R-1
400 600
72
loooot
6000 5000 4000
3000+
laquo2000 e
r 1000
raquo 600 pound 600 ~ 400
$ 300 a a lt 200
100
Legend
A actual field measurement
-Qmdashinterpretation
10 20 30 40 50 100 200 400 600 Distance AB2 feet
Fig 28 Schlumberger Sounding R-2
73
Formula T = f
Background Sounding (9000)(15) = (3110j (1 7) + gt2(8)
= 16214 n- ft
W Wel l Sounding (b200)(60) = (500) (2) + pound2(28)
= 13250 SL- ft
To determine a resistivityp3 value for the third layer a
graphical interpretation for the longitudinal conductance S was
used(48) This is eaual to the sum of each individual layers depth
divided by their apparent resistivity
Formula S = -r1 +~r-raquobull-ra
Background Sounding 0017 = yyg + ~^
= IbOU - ft
W Well Sounding 0285 raquo -ggg 7^3 J~
= 179 v-ft
These values were input to a program which calculates a
schlumberger sounding curve (47) The theoretical sounding curves
approximately match the field curve as viewed on fig 27 and fig
28 To provide a check on the apparent resistivity of the saturated
layer at the W well the following relationship was applied 1OOOO
= spec-jfic conductance (umhos)
74
At the W well the specific conductance was measured to be 3 00
jmhos at approximately 10degC
Assuming a formation factor of 45 for the glacial outwash (23)
material Archies law is applied to estimate an apparent resistivity
of the third layer (7)
fgt FF x p
A= 45 x 103-n-ft
A= 4G3 JL-ft
This is a reasonable approximation to tne 3i= 179^-ft calculated
analytically from the sounding curve interpretation
75
Remedial Measures
With the analysis of f low patterns and contamination zones
recommendations to minimize the environmental impact of the leachate
can be reviewed The basic technique is to minimize all sources of
water reaching the refuse so that leacnate production is minimized
The oiversion of precipitation by a relatively impermeable cover and
proper channeling of runoff would minimize percolation into landfill
material Caps and seals can be constructed of clays fly ash
soils soil-cement lime stabilized soil memorane liners
bituminous concrete and asphalttar materials (15) Proper
contouring and grading will help minimize infiltration If a soil
cover is used a vegetative cover can be planted which will utilize
some of the infiltrating flow through evapotranspiration losses
during the growing season By minimizing the length of slopes and
providing proper drainage channels tne surface runoff can be
conveyed to a downgradient area outside the recharge zone
Therefore this surface water will not increase leachate production
from the landfill Also by increasing the slope of the cover over
the landfill itself a higher percentage of runoff and lower
infiltration will occur
To minimize upgradient ground-water influx to the landfill an
impermeable subsurface barrier or intercepting trench could be
used Barriers can be made of bentonite slurry-trench cutoff walls
grout curtains or sheet piling cutoff wal ls extending to the bedrocic
or an impervious layer to effectively prevent water passage or
create a head loss that wil l lower the water table In addition an
76
intercepting trench which has a perforated drain at tne lowest part
of the water seepage zone could be used to intercept and divert the
entire flow
These possibilities have been evaluated with the help of the
model to determine workable solutions for this landfill The
primary concern is to eliminate leachate flows to domestic wells
Initially a simulation was run that eliminated recharge over tne
landfill area (Fig 29) This had a considerable effect on the
ground-water flow patterns of the landfill area The mounding that
had previously occurred under normal recharge conditions was
eliminated and a general drop in the water taole within the landfill
of 2-3 ft occurred The effect of eliminating recnarge over the
landfill when the upper stream is running would cause greater
infiltration from the stream as evidenced by only a 2 ft head loss
in the landfills flow conditions This is evident when comparing
Fig 29 with Fig 24 Tnis indicates that this measure would only
marginally reduce the resultant leachate flow from the landfill
material that lies below the water table In another situation
where there is not such a strong potential for upgradient flow this
measure has proven quite effective (6) In this case the landfill
cover consisted of four layers an intermediate sand and gravel
cover immediately above tne regraded waste materials a 4 inch sana
bed designed to protect the overlying membrane a ilO mil flexible
PVC membrane and an 18 inch final cover of sand and gravel
77
Legend
landfill limit -raquo- -^ -raquobull excava t ion x-^x- s t ream
400 copy WNWNEECSESC monitoring well locations
= -= unimproved road fee t
Fig 29 No Recharge over Landfill
78
Controls such as 10-30 mil polyvinyl chloride covers favor the
development of an anaerobic environment which increases waste
decomposition time and would necessitate installation of gas vents
at several locations on the landfill cover Tne integrity of tne
synthetic cap may be further threatened by subsidence which create
differential stresses on liners Settlement would create areas for
ponding and depression storage and eventually necessitate regrading
the landfill surface The landfills south-central area has oeen
filled within the last year and will prooably need to be regraded
due to settlement within the next few years
Another possibility for a liner would be a soil-bentonite
cover A layered cover consisting of natural materials with low
permeabilities such as bentonite clay followed by a layer of highly
permeable material such as sand and finally a layer of topsoil can
be used Due to potential drying out and cracking of the clay liner
a synthetic liner is the preferred method
The most immediate technique is to grade contour and vegetate
the landfill cover which has been done at this site Althougn an
impermeable cover would probaoly reduce the amount of leachate
produced it would not eliminate the upgradient flow and provide
guaranteed protection of wells in the vicinity of the landfills
northwestern section
A slurry trench along the northwestern perimeter of the landfill
would effectively cutoff upgradient infiltration and divert recharge
infiltration in a southeasterly direction thus removing possible
leachate outflows from the radius of influence of the neighooring
79
wells This has been simulated using the computer moael ana flow
patterns as shown in Fig 30 Contour lines are distorted in the
vicinity of the slurry trench due to the 200 ft nodal spacing
Transmissivity values of 1 ftday were input at the slurry
locations to simulate an impermeable barrier Tne surface recharge
at those nodes does not infiltrate the relatively impermeable grid
nodes at the slurry locations and flows to the edge of the noae
thus creating a dramatic head loss within a short spacing To
effectively simulate this a variable grid spacing should be used
with reduced node grid spacing at trench locations to eliminate
distortion The computer simulation shows that the slurry trench
could direct flow in the landfill area in a southeasterly direction
and away from endangered wells In addition it would reduce
upgradient infiltration from the stream into the landfill This
measure would prevent leachate from spreading beyond this carrier to
possibly contaminate neighboring wells
The combination of both the slurry wall and impermeable cover
would be ideal measures to minimize generation of leachate and to
stop its spread to neighboring wells The slurry wall without
recharge over it or the landfill is simulated in Fig 31 This
indicates a lower water table tnan eliminating the recharge to the
landfill The slurry wall has blocked upgradient ground-water flow
at its location to the landfill
80
Legend
landfill limit -laquo- j -laquobull excava t ion ^^- stream
copy WNWNEECSESC monitoring well locations
= = = unimproved road ssi slurry wall
f e e t
Fig 30 Slurry Wall
81
Legend
landfill limit j- j- J- excavat ion x-v^gt- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road s==s slurry wall
400
feet
Fig 31 Slurry Wall without Recharge Over It or Landfill
82
An intercepting drainage trench is considered next If a trench
was excavated to a 30 ft depth in the outwash material extensive
shoring would be required In addition difficulties would arise
when the trench was excavated below the waterline Tne trench would
be sloped to provide drainage and backfilled with a highly pervious
material to intercept and divert leacnate locally a conouit which
is perforated on the top to allow infiltration and unperforated on
its lower perimeter to permit continuous drainage to the collection
treatment center would be installed on the bottom of the graded
trench The difficulties involved in excavating below the water
table ano shoring the sidewalls to permit implacement of a drainage
conduit at a 30 foot depth make this option increasingly infeasible
83
Conclusions and Recommendations
The location of the South Kingstown landfill in permeable sand
and gravel glacial outwash material (107 ftday) combined with the
high hydraulic gradient across the landfill area (20 ft1600 ft)
creates a high potential for ground-water contamination to occur
This is intensified because refuse nas been placed below the water
table The low hydraulic conductivity of the compacted refuse (1
ftday) and the excavated area to the west of Rose Hill Road have
both contributed to modifying the original southeasterly flow
pattern These modifications have created a ground-water divide in
the landfill at approximately the western third section Tnis
results in approximately 13 of the leachate flow from the landfill
or 63 gpm flowing in a southwesterly direction and 23 or 129
gpm flows in a southeasterly direction Infiltration from
precipitation recnarge over the landfill (up to 9Upound) and from tne
upgradient stream during low water-table periods provides tne
necessary influx into the landfill Evidence of contamination is
clearly seen on both the east and west sides of the landfill which
reinforces the previously stated flow patterns
Of the several remedial measures reviewed the contouring and
grading of the landfill topcover and drainage swale provides the
most immediate protection The topcover has been graded mulched
and seeded to provide a low runoff slope generally to the east
The drainage swale on the left side of the landfill has improperly
graded sections which should be corrected Its northern section
could be drained into the northern sections swale and the southern
84
section drained to the southeastern section of the landfill Tne
point of the drainage swale which divides the northern drainage
swale from the southern one should be determined by a field survey
Cost is a major contributing factor when determining which
remedial measure is to be applied to the given situation For the
purpose of this report cost estimates are not presented but rather
the effectiveness and feasibility of the remedial measures are tne
primary considerations As was reviewed and simulated in the
computer models the slurry trench and impermeable cover over the
landfill are two viable options that would effectively provide
protection to the domestic supply wells in tne vicinity The
impermeable cover would eliminate precipitation recharge into tne
landfill yet drop the water table only a few feet due to upgradient
infiltration from the stream This would decrease the hydraulic
gradient thus diminishing the potential for a contaminant outflow to
surrounding wells The supply well of primary concern is one to the
west of Rose Hi l l Road marked well D on Fig 2 If contamination
occurs in this well the most effective measure would be to block
off leachate flow in this direction by installing a bentonite slurry
trench at the location indicated previously This would effectively
prevent leachate flow in the westerly direction and diverts it to a
more southeasterly direction In addition the slurry trench
precludes infiltration flow into the landfill from the upgradient
stream
85
Tnis report has effectively reviewed tne original ana existing
flow conditions and contaminant levels in the vicinity of the Rose
Hill landfill The purpose was to provide an understanding of
ground-water contamination patterns and study possiole remedial
measures
86lt
Appendix A
Precipitation Records
Monthly normal precipitation 1941 -197O
i$l Total monthly precipitation
KINGSTON RI
14
ia
^JO T I bullbullL
pound 111 laquobull
4
a
n
-
^
-
-
KS1JAN
^Ii R3 HB MAR
1
1 APR MAY
1
1 JUN
1981
JUL
-bullraquolaquo H
AUO SEP
K3~~f$s bull
_imdash
i1S 1
OCf NOV OtC
171 1 iI1
JAN HB MAR APR MAY
198
Fig 32 Precipitation Record
- - - -
IM 1 MtvJrflgtlgt c ortli-A t lUN I r nraquo rl - -
gt|MO CLIMATOLOQICAL OUSERV ATIONshyr-r bull JK gt raquo - 1
i5fWA I VAPOR Al IOH -bull AIM If MPCRATUM bullF 0 riccipn AT ION UNO IlMf
bull 14 H 14 H mdash Vshy ADDITIONAL DATA IfUAlUS OATt 1 bull raquof bull bull 1 ta
14 Hw rlaquo4 w bullbull bull 1 114 1mdash4 (llrl 1 1 1fl Hll
0 kmdash
Mraquo M4 raquo i T i 4 bullraquo-laquobull i i
Lgt f 1 21 S 1 Hbull - - bullbull -
ltJL 1 2 01 - - _ _ 1
mdash
-
1 12 _ Q I
mdash shy
mdash 4 (C ( - - fVi 1 - 0
1 (1
^ 1
Vvraquolaquo IJ1^ raquo CP O 3L 1 Z - i bull j-t-J
1 J
LH Vb T n 0
1 gt fl oo O ~l 2 L - bull 1 P )laquo jn iP IP - OOI L5L mdash shy
-t 84 ^(^^ ^fi P i flja 0 JO II 10 tl tcgt 7 J IV wllaquo
h l2L bull 0 lt -_ shy
-id VJ lt 3C 2 ft OOL -mdash
U 71 C1 Sr 2 13 2 nl JLJraquopound HP r M ltf1- (
IMe 2 ii O It
n jlt dl 1 1 bull o o-il ST i 1 i 25 2-x-1
-
ri
i tlL O mdash gtbull bullgtlt 1ft -o- is Oil So iJK 2-io otv u 31 fil loi 2 il Oll it Of wr is i1raquo -iZ 1 deg|0 01
M IT So - mdash
- 13 1 CT mdash i - mdash 21
shy
Tl Ci av ZUll IMT 0 IM Pe v _ 1) T) S) ii3( dlt Ii 2 lt^2 II li- S1 riivi To 7HX lt3lO 14 ^2- iTi I li 011 -- - -i -^IS no 5^ or i | T Jift laquoV OoH bullla It Va iCO mdash L OIL 11 bullvf poundgtpound lS_ flv oh P-lfe 1 poif _ shy11 IB kl (4 itlaquoT lamp llt0 oot^
mdash -n
It T1 |ir( L1 HI 2 0 oil
U 1M ft go C ICf^ -^2 Z laquo-|o
11 it 5 bulln - TO o abull Li u-i IT1 -- Iw O ltM (I bullbull bdquo-I(K 1mdash -tilltLlA ttfe
i Dgt ac -- U 44 4 11 1 1- ytd i i_i J-K 0 i if -i i i V t Wl raquoOHM 1-1 US D C P A R T M f N T OF COMMfRCE t 4 1 IUII 1 1 ^~) mdash
llaquo- Hi NC bull bullh bull bullJL^V HBl CO 00
11
)jLsVyr^gturv
^ | TKu
|-_t_ bull(
IIMgt I I Mt|UU III- II 11
PNECIPITATIOH
I 1 1 IMX
IMO
bull llfclaquo I UCIUKI) Ur C V A r U M A AHO CLIMATOUOCICAL OBitH
E V A F O R A T I C r i Jttffl laquo amp hMIlaquoJllaquoJIIlaquoBgt
DATE AOOITIOMAL DAIAKMAKk M
bullraquobullmdashlaquo
tp 01 (1 Of Ll OOI ooo
0^1 o-i 10 tl |00 102
OC (1 13 Ofl
it i rc DS os an
(1 SV o
Ul 010
(ISl 101 I on
130
II 5= Otl
ss lt 001 (IK Ml
jt il HIT
7 it
ow Wo 17 Top 2-01 OIO
(0 oov zi oot
u CO ^A 0 to Zoi CLflS
bull50 01 ljtj
nshy 5H LO OIt
50121 IVO QJO
14 Co Ho LO Hl ^pound Jl 1
ltM ool fllc
H Tl 01 II
11 11 Q1
iH OIO
HO 2 llaquol 11 II
lifc
IV-IIM ul OIPAITHINT or COHMIICC NOAA
NAtlOHAL gtIATnlaquoll raquotraquoVlClaquo CD
r~
All TCUMMATUNI ^V UII rgt ITmi 1 Cwphu Obic i gtn t ngir-H 30
rilCiriTATIOH
JJ T I rTJ-rimdashr-iramj|MP CLmATOLOQ
laquolaquo jftilCiii bullIHO
Oi1l ADOITIOHAL DAIAlllu
Ilf4ft
Sii1
(1 2 IO OO
Hl ii SO
us OIM
Q^L
a A3 Hi SZ Sf^ bull 12J2
HI Z-SF OOl 1C t HM IA H ICP fiJA
OOl 10 (310 sn 310
if HI (0 ^01
bullit SO 28H poundJ1 11 006
14 35 TX oon II (bull2 it zr II c-S
rr Zll lo 31 OP an 31 a 31 oor
CSW O-ll Si CC Of 011
Oll _ I |ft
00
u i oerraquolaquoTMiMr of c NOAA
NATIONAL K C A T N C M SCMVlCC
TC^S lk)oiVroTJA
TETT I 7X
1raquolaquolaquo 4 bdquo ir lt er ni I^OV ltqgl j--^ TQ
MICiriTAllOH ITIND
D|mdash
b5NO ctiUATOtoiCAL oeit^
OATI AOOITIOMAL OATAVlHAtt
0-tt
Mlaquoh bullbullbull- rshy laquo
I- ltltriu HI I 4 bulllaquobullbull1
Zii
30 Dfellt otvt
at HA
OOI
62
iJ_S2 HI if
bull- 20 SI 2i So
So
VVfr
OSfc
I (
Jtlt
3aoi
r j -bull ie MA
Irill iiol
in^ 14
Mo
Zll
214
21 1P
00-i
bulliron
17
bullr
11 i ir- I J Ktf^c
US D E P A R T M E N T OF COuMEDCC I | C gt A A
K AIlaquo Ttupf lATuit r
|SlVi AlJ PIICIPITATION
oJud (El
VIM i Uraquo
MIND E
EVAPORATIOH flnrft bull A ftufiifccdll
KECORO OF eVAPllHAtlil bull I CLIHATOLOOCAL OBSERVA ^Hij
14 MM A_M AOOIIIONAL DATA11 MAIM
Mr bullH Oo|
M Si lift
bull221 IHI
ZS Ji 40 IZV
icr KS I
HZ 111
bullT 21
loA UK JA IP
v^ ft
1M 2Sshy IT Tl
71 V |
i I 31 1deg a
uty^ U bull3
ons 1 CiO TxX
HHO (10
3H 19 12 10 IP
raquo3H raquo | 5t io
OP OIT
14
vO UI Of PANTMINI Or COMMCRCf MM O A A
F ngt TIHH
iiicffwiffc 4 rJ (TIM bull Cempltit Obitittiio
AIlaquo TIMHIATUM PHICinTATION I V A f OK ATlPrl
OATI ADDITIONAL DATA KMAlIt
U4laquo4 +
03H Ji
10
rc a 1 16 oi ii
tiiy 10
OI
II i23 or o 13 -y~ou HO
II 3V III i 3 t
V laquop oot
OM1 SS ne
T an -i IP
Olt zr LTV
3T 001
a -11 2T
10 an 31
-1 raquo 131 UP 3H lf 14 Lpoundshy
it 14 30
IS
Ui O I P A K T M f H T OP COWlf ICfM O A A
NATJONAI V C A T M C n f t K M V l C K
bullbullbullbullbullshy -2 o AIlaquo TIMMRATUM f fKICIPITATIOH
OATI poundt- MMINMAL DATAk
ZP 51 lo icr
011 111
OoT IHf
Ut 003 am
3o 13 ao
4A X 05shy
H4 i IjJyiV131 ooc js
IH oi 01 tL 18 13 a
No 11-7
rivgtp OO| M Hi 03 01
It 12
bull I 41 bull7119 14 ^^ raquo 31 15 lampk n M ho i
Jo -j-
-J
I
Ml H^ I _
amp2ampUi^= LS 0 S 0-f bullTTT
-Vmdash gt U_ bull 1 rOHM I- 11 OI OCPARTMlNT OF COMM(NCC
HO NATIONAL W f A T M f H ftfraquoVlCI
98
Appendix B
Boring Logs
99
X iHECT 1 ff 2
OAT American Drilling amp Bor ini I Co Inc
wo WATH smn EAST PR ov IDENC E ft 1 Town of South Kingstown South K ngstown R I MOLENO X-J
TC 100 RCSS bull ujrMonitorinq Well Installation | South Kinqjtown R I UNC a STA Pf KXICCTHJ LOC ATK3N
bull cfrserrr TO above S MPLES S FNTTO _ _ |laquolaquor A-109 SURF ELEV RE PORTSEr
GROUND WATER O6SE RVATC MS 1 CDREraquolaquo m-T nn75 laquo A 256 - 20 mdash Hew y
Instolled 32ofT-l2 PV C - JO- COMPUTE 111275 K toia 3- I-WI 1-38 TOTAL MRS bdquo10 screen BORING FCACUAM J K lanq MAI rraquo HomnwWI 300 140 IampPCCrc Mamlaquor Fall 24 30 lampaaiona SOLS ENGR
LOCATION OF BORING H ONITOKING WELL
Coung Samplt Tjp Blow per 6 Manure SOU IDENTIFICATION Strata SAMPLE ^^^yV Bloot
foot
Otptni
From- To
el
l
on Sampler
0-6 1 -6-13 12-18
Dentity or
Conmt j
Chang Remark include colo^ graaation Type of tod lie Rao-coMr type condition nordshynetiDntotf time leamt and tie No Pen Rtlt
2 No top sample 5 12
1 loamy fine sand
bull)^ 40 30 36
5- 616 0 23 20 16
noist iense
Brown fine to coarse SAND some fine to coarse gravel Trace silt
^
1 18 18
36 8-0shy57 40 30 V 35
|0-||-6 D 14 24 20 Srown medium to coarse SAND Some fine gravel cobbles
7 IRshy 16
27 75 37 3
IS- I- D 5 14 16 3bull
ISshy 15
42 50 I9--0shy50 65 20-2ll-6 D 9 23 26 bull Jrown fine to coarse SAND Tbullwshy 1Z 75 90
22-0 Trace silt trace fine gravel
124 120 74 60 52 41
7S-ltlaquoil-A DX 71 16 13 wet very dense
Gray-brown fine to coarse SANC Some fine to coarse gravel little silt
H IR u
40 30--0
3C-30-IO
3l4-334
334-3314
38 4-434
D
c
C
C
7 IflO
94 6
we tr j
y se
ft irox
30MOshy
31 -4shy
Gray-brown fine to coarse SAND Trace silt
Gray-brown fine SAND some lilt trace fine gravel
Too of Rock 31 -4shy
Gray-pink GRANITE
6 7
amp
CJ
IltJ A
60
601
IQ mdash
2(
4
5 i Hard
ft 5ome seams bull
GROUND SURFACE TO J 4 U3CD_ ^JVrf bullbull( tutu t to 4o 4 SampM Type Proportion UMd MOB Wtx 3 OfaM on 2OD Sampler SUMMARY-
OOry CCartd WltWen4 Hoc OlolO Canmonieraquoi Don any CoKeem CarMWncy Earm Barrlaquoj 11 14
UPgtUnOigtturod Piuon trite (Oto20dego 0-Kgt Loei it 0-4 Sait 3O+Hofd Rock Corng 14 Kgt-30 laquo4 0 rte 4-8 MSHM Samplet TPTtitPit Ai Auger Vvanefett tarn 2Olo39 3O-M Owlt n laquo-lS Strlf rinit nn v 1
UTiUndlshffbed ThrMOll and bull 33to9O 5O Very 0laquo nraquoe 19-30 V-3trraquof - | OLE NO X-l
TOVH rim - iA it raquotoraquo
100
SHEET 2 o_L
WO WATEt STUET [AST ft OVIDENC pound a i American Drilling amp Bor ing Co Inc
MCLl WQ X- 1 Tt AOORCSS i
LIME A STA KXICCTMJ tuf same as 1 | tame as i LOCATION
W PORTSEf mo OB nj urt eflaquo T
illtPLES S
P
CVTTO nlaquo mun orv
^s f^ Tin i GRCVMO WATER OBSERVATONS CASING SAMPLER CORE BAR
START Typi COMPUTE tome at 1 same aiH
TOTAL MRS BORIMG FOR CMAN n bull IT INSPECTOR SOILS EMM
LOCATION OF BORING u HfVJTneTfi UFI _
8
Counf Blo-t
foot
Dtpllo
From To
0( on SampMr
0-6 f 6-IZ
Moittir
Oonuty or
Contilt
Strata Ctnngc
SOIL OCNTiriCATION Rtmorkt ineHifl cotot grqdotion Typlaquo of Mil etc Roo-axtrPlaquo condition Mrdshynlaquot Drog tun ttomt end tic
SAMPLE
No Ptfl RfK
434-4o4 c
approx 7 minj
per toot 454
Gray pink GRANITE Hard Fairly solid core
lt_4 24
Bottom of Boring 45 -4
-
~
bull 1
GROUND Sorrow Tye
SURHCZ 10
bull OiOry CgtCord WWothod UPUnditiurMd Piston TPlaquoTtraquotPtt AtAuotr VVor
UTltUndinrvd TTMMO bull bulltat
iivnPilaquo(onioni Uraquot4
me OioiOItttt laquoraquo20
wmt Z0ie33
and 361090
c M
C1 5 Si
-SOshy
ASING
IOtgtWtigt bullnlot Dn 10 Loci M Mod 04 SO Dm 1shy Viry 0laquo
s _
TMEN 0 hMl on 200 SoiTBUr laquoity ConcMMt Conorawncy gtbull 0-4 Sort 30shym 4-B MStlfl M BH9 Strtf bull ts-so v-swt bull
t-HOrt Ear Bern RoetCorrt
i ^^^^^ bull
-[MOLE no x-i
101
raquoMEC rAmerican Drilling amp Bor in g Co Inc 1 ofj_ DATE wo WATlaquo smn UST Plaquo IOIDCNC j laquo i
Town of South Kingstown South Kingstown 8 MOLE MO Jlt Z TC rx MCS3
rtprr uAurMonitorina Well Initollation | South KinqitowrxRI UNC A STA P KATIOM ME POCT ^rwT TO above I OFFSZT
uD^r laquorlaquorTTO 6 -109 suw tLEv Sgt louffJOCNO
0 tj Tlmlaquo WOUND WATER 06SCRVATC US gtW Rsdl SING SAM^EH CORE BAH
26 ^_ 12 $TAlaquoT UL 2Z2i Ji r TTP NW ltA sr IJZC Z5 CCOMPLETE
SitLO 3 I-3B- 1-38 TOTAL MAS 41 BOAINO FOACMAN JK1 ana nf ni n MonwwWl 300^ 140 BIT bullK^CT
gttonvrar Foil J^laquo 30mdash Diamond SOOJIEMGM
IE HFII
iCaunq SampM Trplaquo BMMtpw6 UOIIIK- SOIL DCMTIFKATION Siraia SAUPLE Blow DlaquoPIAraquo of on SompMr HtmorU mcJuo cotes gradation Type of Dwuily
pw or CXang writK Roel-eolorlyp condition tvort-From- To Vfoot 0-6 f 6-2 12-18 Coniitt egt rwtiOnAngtimt wamaondtte No Praquon Rtlt
2 Brown fine SAND little silt 2 2-0shy5 15 18 moist Browi fin to coarse SAND 18 5- 6-6 0 14 25 27 vlaquo Troc fin aravel | 25 wy Ifl 11
dlt tns 35 40 38 moist n in-il-i Lgt U 15 18 ie is li1 Irl IS 31 I2-0
~~43 1
A) Jrown coars to medium SAI MD 48 moist Little fine to coarse gravel
|5-IA-Xlaquo 14 47 41 fn D laquo y Little silt rrqa coarse sane 3 18 I1
68 In IS 44 32 34
n ^n-^i-A- w 2o 19 29 wet 4 la -59 lens ltfO no
25-0 2amp bulllaquo- 77 c BOULDER r[ 4 i
27-0 5X ~W 24 24 bullWar- 5 Ifl irown tine to coarse SAND some
dens 29-0- Fine-coars gravel trace silt
30-3I oxx 30 32 30 moist irown -gray fine SANDiom e 6 l rr Vlaquoy 31 -0 silt trace fine oroveTILL
Bottom of Boring 31 -ampbull shyBent casing -pulled out and moved over 4 - washed amp tJrovlaquo casing to 30 -Installed 3C gtof 1-12- PVC - 10 screen
WOUND SUraquoraquofCE TO 3pound 1 yijfD MW t ASIMC TMCJ laquo olaquorod -bor of borina
SomoU T]Fplaquo ProigtuliOraquoH UMd MIOtgtWLx3Orolt lon2OASanlaquoMr SUUMARY-D=Dry CCorad Wlaquoworaquonraquod bullact OiaiO CanM gnMM Daonty CIMIH Caamraquoci EffW 8or^ 2pt
UPiUnairurMd Pition Itnt laquoM2O O- O UKraquolaquo 0-4 Soft 3O-hHard Roelaquo Corrig o- JO M0mlaquo 4-8 MSNff SOTipM 1 p^ 3O-9O OwgtM bull-IS Slid
TPlaquoTraquojraquoPit AAugtr ViVon mini tamt 20to39 UTtundiifir6d TrwMOtf and JSloSO 50-raquobull Vary 0nlaquo [HOLE NO x-2 B-3O V-3Mf lev rim - IAIT raquosectlaquoraquo
102
300 iu 24
1 UMnii ffi 140 laquo 30
CA1INC tf
gt taWCTf
bull 0gtlaquo i R Cook Jr_ R Millineton1 Wttn
I~
1 VAMtl CtMG
1 W HO-t MO
1 Oraquo 1 laquo0~ twt
L 1 laquo-raquo VfcM^lf [wlaquoraquoCI ^ ^ K3Ot III laquo
0-LS D
5-65 D
LlQ 10-115 D
15-16 Tgt
Lraquo 70-51 n
25-26 D
F
I O-O Ci
A Allstate Drill ins Co vi o i
PROVIDING R 1bull raquoraquo uvraquonn~ N M O M I T O P I N G HE1 _^lt -^ PI-Traquo UJU
CUM Town of South Kineraquotown raquoraquo 1 1TA maoer Propolaquolaquod Sit for Slude Disposal nltn
laquo V-449 iampAAtut i a 138 ort STI bull r 42777 CtOuMO IKVtllON
Cill bdquo 258 DA II MN ru 42777 rilaquolaquodO laquoraquoTti rum 1911
AU1TATI
MMUI1 raquolaquogtlaquolaquo laquoKiO itXHHKraquoriOi of sous MUAHI nMTKlion Ot CMlaquoMC|kOraquort tl CO~VH DXltgt raquomlaquo laquotf IMi COIOI C4l II I 1raquo gtlaquo^ Oraquo 1Ol rC t Xgttgt VtfKOe Craquo Mi 1 ft liMraquoK laquo0^tlaquot nfgt
1-2-1 10 TOP SOIL FINE LIGHT BROWN SAND traclaquo of ilt
16-31-17
22-24-21 100 FINE TO MEDIUM LIGHT GRAY SAND trace of fine gravlaquol and raquopoundLt
lfl-37-34 150 LIGHT BROWN FINE TO MEDIUM SAND little poundinlaquo gravel
21-17-15 200 MEDIUM TO COARSE SAND bullomc fine gravel
12-4-10
265
Observation well installed
NOTE No casing blows taktn
bullbull B-23 ow
^w^ 265 I raquo bull raquolaquo bull I W
11 laquot gtbullraquo Vlaquo 14 W gt_ c-shyji bull alaquo bull jraquo VI laquoHshyw bullbull m raquobullbull D-6 raquo Mshy
bull bull laquo Vshy
1
bull bull
I
103
MAMMII Allstate Drilling Co ulaquorr 1 or 1 FftOVIOCKZ H L traquolS mTArm^S MONITOR NR WEL
VNO wr3JJO__raquoraquou_24__ HCU MO P-74 n iu riBwi Town of Slt7H^ Xirpin
mdash^ laquo0J P 1 1 bull ^n^ciit^o TVlaquow^laquott1 bullraquoit wt 140 nu 30 olaquor fBu lkv Waste Disposal Arcai
MUTAH a V-449 R Cook Jr UMlaquoiigti D 1 38 0t| raquoIJ raquo 5277 rlaquo SUMO luvlaquorv-laquow
mdash 5277 fipe -raquoT pfpm 150
H MCIO IMNTlXAflON Of SOU t(kAIlaquoS rrn 0-laquoraquo
5 -SF 01 w in laquobull -raquo ^ lit
D 1-2-2 TOP SOIL V-1-oraquo
15 IPbull FINE TO MEDIUM LIGHT GRAY SAND AND GRAVEL
5-65 D 37-27-35 some silt
10-11 D 20-14-18
15-165 D i 17-14-14 155
BROWN COARSE TO MEDIUM SAND little fine to coarse gravel trace of silt
20-211 D 4-4-2
230 GRAY BROWN VERY FINE SAND
25-26J D 7-8-9 AND SILT 265 fvarvedl
Observation well installed
NOTE No casing blows taken
wta 10 n uuraquo c^imdashbull IgtM laquolaquobull- B-24 ow ~ 14 ltfc laquoraquobull vlaquo^ M laquobull r O 0 fmtt bull W-L 26 5
-0- CgtCmdashgt bull laquolaquobull mdash laquo 1 - raquoraquo 1 gt 1laquo bull 1 gtraquor to bull mdashbull bull bull bulllaquo I t l~laquo 1lt Uraquo mdashbull ) bull 1 gtbull ft 0~ H laquoy bullM ta bull -IN la laquobull OPUM bull($ IMI
mdash H raquo laquo-bull
104
Appendix C
Calibration of Specific Conductance Meters
105
Specific conductance measurements were made using a beckman RB
338 temperature compensating meter and a YSI rtooel 33 salinity
conductivity temperature meter The YSI meter is not
temperature correcting A formula to compensate for temperature
differences to standardize YSI measurements was used (21)
A long probe for the Beckman meter was used to measure conductivity
in the wells Differences in conductivity between the YSI ana
Beckman meters and the Beckman short and long probes exist These
were calibrated in the laboratory using 001 N and 01 N KC1
solutions Values presented are Beckman short probe values The
Beckman long probe values were reduced by 76 and tne YSI values
were multiplied by 11 to adjust to Beckman short probe values The
YSI meter was used in the latter phases of the study for the
stream contamination due to the greater accuracy of the dial readout
scale
Table 7 Specific Conductance Meter Calibration Table
Concentration (KCL) 0001N 001N
Specific Beckman short 145 143 143 1247 1245 12GO
Conductances Beckman long 190 191 188 1639 1650 1665
umhocm 9 25 C YSI 132 131 128 1131 1140 1150
average values Beckman shortBeckman long = 075
Beckman shortYSI = 11
106
Appendix D
Computer program Flow Chart
107
F1g 33 Computer Program Flow Chart-
1TpoundR MAP TCO
NEWPER
WEWSTP CZAX
HEWIT TRANS TCOF ROW COLUMN
Yes
Yes
108 The following is a description of the USGS two-dimensional computer
program Iterative Digital Model for Aquifer Evaluation updated
December 1972 by P C Trescott The program written in Fortran
consists of a MAIN program and six subprograms or subroutines which
themselves are organized into subprogram sections The subroutines and
their sections are listed below
MAIN Program
DATAIN (subroutine) COEF ITER (section) CLAY MAP TRANS NEWPER TCOF
ETRATE COMPUT STORAG
NEWSTP LEAKAG NEWIT1 NEWITO CHECK ROW CWRITE COLUMN STEADY PRNTA OUTPUT DRY BLOCK DATA
The program begins in the MAIN program which controls the sequence
of passage to the subroutines Sequential steps are described in the
program as shown in the flow chart of Fig 32 Emphasis is placed on the
steady state confined aquifer case as applied in this study First data
input is read in the DATAIN subroutine This data includes transmissivities
or permeabilities starting heads storage coefficients and grid spacings
Nodal transmissivity values are then computed for the water-table problem
in the TRANS section (COEF subroutine) This procedure is necessary here
because the subsequent routine for computing iteration parameters (ITER)
keys on nodal transmissivity values which would not have been input to
the water-table problem In the water-table option these would have been
109
computed from given bedrock and water-table elevations to obtain the
saturated thickness component of the transmissivity calculation In this
study water-table option was not used and the transmissivity values were
input directly The program then passes to the ITER section (DATAIN
subroutine) to compute the iteration parameters which expediate or even
cause convergence Next the MAP section (DATAIN subroutine) is utilized
to initialize data for an alphanumeric map if this was requested in the
input options Transmissivities are then computed for the confined
(artesian) aquifer case (water table not specified with input options)
in the TCOF section (COEF subroutine) These coefficients are harmonic
mean values of adjacent nodal transmissivities weighted by grid sizes
Time parameters and pumping data for a new pumping period are then read
in the NEWPER section (DATAIN subroutine) followed by entry into the
NEWSTP section (COMPUT subroutine) which calculates the size of the
time step Leakage coefficients (hydraulic conductivity of the confining
bed divided by confining bed thickness) are next computed in the CLAY
section (COEF subroutine) if leakage was specified in the input data
which was used in this study
A new iteration is then initiated in sections NEWITO (COMPUT
subroutine) NEWITO saves the current head values and compares them to
the updated head values for determining closure This is followed by
nodal transmissivity values being computed for the water table or water-
table artesian conversion problem Transmissivity coefficients are then
computed for the water-table problem in TCOF (COEF subroutine) Total
head values are then computed with the alternating direction implicit
procedure using the Thomas algorithim first along rows in the ROW section
110 and then along columns in the COLUMN section both in the COMPUT subroutine
Then if a solution is not obtained (because the error criteria for
closure is not satisfied) the MAIN program branches back to NEWIT1 subshy
sequent sections TRANS TCOF ROW and COLUMN repeatedly until a
solution at the particular time step is achieved NEWIT1 increments the
iteration counter and is immediately followed by NEWITO The program then
moves to the STEADY section of the COMPUT subroutine to check if the
closure criteria for steady state has been satisfied Output is then
printed in the OUTPUT section of COMPUT if steady state has been reached
or if the particular time step is designated for output
The program then branches back to NEWSTP (COMPUT subroutine) and
moves through the subsequent routines until the last time step in the
pumping period is reached Output is then promoted in the DRY section
of COMPUT if specified in input data If the last pumping period in
the problem has not been reached the program branches back to the
NEWPER section and moves again through subsequent sections otherwise
the program will terminate or start a new problem if one follows
This study was simulated as a steady state problem which can be
simulated by setting the storage coefficient of the aquifer and the
specific storage of the confining bed to zero and using one time step
of any length
111
Appendix E
Computer Data Sheets
RGSEA
10 ROSE HILL LANDFILL MODEL 20 30 40 LEAKAGE 50 60 70 CHECK 80 90 100 HEAD 110 120 1 23 IQ 100 5 001 37E-OU 0 130 100 001 0 0 1 4 0 - 1 - 1 1 - 1 - 1 i i i i i i 1
ISO 1 10 0 1547E-05 01 10 1 1 160 04642 200 200 1 1 i it
1QO 190
CARDS I THROUGH 19 - CODING SHEET
CHEAD
100 110 120 130 131 132 140 141 142 150 151 152 160 161 162 163 164 165 170 171 172 173 174 175 176 177 178 179 1BO 101 190 191 192
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 539
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 58
25
25
25
25
25
25 621
25
25
25
25
25 662
25 25
25
CARD SET 2 - STARTING HEAD MATRIX (FT)
193 194 IVb 196 197 190 200 201 202 210 211 212 220 221 222 223 bull 224 225 230 231 232 233 234 235 236 237 23B 239 240 241 250 251 252 253 254 255
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 23 25 25 25 25 25
25 25 - 25 25 25 25 25 25 25 25 25- 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 - 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25
25 25
25
25 25
25 25
25 25
25
25 25
25
25 25
25
25
25
25 25
25 25
25
25 25
25 25
25 25
25
25
25 25
25
25 25
CARD SET 2 - STARTING HEAD MATRIX (FT) - continued
STORC 1512 FRI 19 FEB 82
100 110 -1 -1 - 1 - 1 0 0 120 130 140 ISO 160 170 100 190 200 210 220 230 240 230 251 260 261 262 263 270 271
CARD SET 3 - STORAGE COEFFICENT
LEAK
100 110 120 02 130 _ 18 02
I ltu 18140 025 150 02015015015 19 deg25
02 160 022 bull-laquo- J1 5 j 1 z laquo- l^
170 015 180 016 laquo02
190 016 OE025
200 02504019022021025 2 5 i S lt03 0252i2 n
230 030 deg23 deg2 deg2 deg2 -02023023 240 022 250 022025025 02
027043 013025
30() 025025025 310 025031 320 024025
CARD SET 5 - AREA OF STEAMBEDAREA OF NODE
120
Appendix F
Bibliography
121 BIBLIOGRAPHY
1 Agpar MA and 0 Langmuir Ground-Water Pollution Potential of a Landfill Above tne Water Table Groundwater V 9 No 6 1971 pp 76-96
2 Allen William B Hahn GW and RA Brackley Availability of Ground Water Upper Pawcatuck River Basin Rhode Island USGS US Government Printing-office GS 66-624 19bb
3 Annual Book of ASTM Standards Part 31 Open Channel Flow Measurement of Water and Waste Water by Weirs D 2034-68 1975
4 Annual Book of ASTM Standards Part 19 Infiltration Rate of Soils in Field Using Double-Ring Infiltrameters D 3385-75 1975
5 Baeaecner MJ and W BacK Hyarogeological Processes and Chemical Reactions of a Landfill Ground Water V 17 no 5 1979 pp 429-437
6 Beck WW Dunn AL and Grover H Emrich Leachate Quality Improvements After Top Sealing1 8th SHwRD MERL Symposium 1982
7 Beckman WK Transient Modeling For Estimating Sustained Aauifer Yield master thesis presented to the University of Rhode Island Kingston RI 1978
8 Bhattacharya PK and HP Patra Direct Current Geoelectric Sounding Elsevier Publishing Co New York 1968 135 p
9 Bouwer H Ground Water Hydrology McGraw-Hill Book Co New Yoric 1978 p 378
10 Braids 0 Cocozza pound Fenn D Isbister J Rous P and B Yarc Procedures Manual for Ground Water Monitoring at Solid Waste Disposal Facilities Environmental Protection Agency530SW-611 Cincinnati Ohio 1977
11 Cartwright K and MR McComas Geophysical Surveys in the Vicinity of Sanitary Landfills in Northeastern Illinois Groundwater V 6 no 5 1968 pp 23-30
12 Cartwright K and Fd Sherman Jr Electrical Earth Resistivity Surveying in Landfill Investigations Reprinted from Proceedings of ohe lOtn Annual Engineering and Soils Engineering Symposium Moscow Idaho 1972
122 13 Clark TP Survey of Ground-Water Protection Methods for
Illinois Landfills Groundwater V 13 no 4 1975 pp 321-331
14 Dunne T and LB Leapold Water in Environmental Planning WH Freeman and Company San Francisco 1978
15 Faro DG Upgrading Hazardous Waste Disposal Sites Remedial Approaches US Environmental Protection Agency500SW-677 Cincinnati Onio 1978
16 Fenn DG Hanley KJ and TV Degeare Use of the Water Balance Method for Predicting Leachate Generation From Solia Waste Disposal Sites US Environmental Protection Agency530SW-lfa8 Cincinnati Ohio 1975
17 Geisser 0 An Electric Analog and Digital Computer Model of the Chipuxet Ground Water^ Aquifer Kingston Rhode Island master thesis presented to the University of Rhode Island Kingston RI 1975
18 Hahn GW Groundwater Map of the Narragansett Pier Quadrangle Rhode Island Rhode Island Water Resources Coordinating Board GWM 5 1959
19 Hemsley William T Koster C Wallace Remedial Technique of Controlling and Treating Low Volume Leachate Discharge USEPA National Conference on Management of Uncontrolled Hazardous Waste Sites Oct 1980
20 Hughes GM RA Landon and RN Farvolden Hydrogeology of Solid Waste Disposal Sites in Northeastern Illinois Final Report to US Environmental Protection Agency PUD SW-l^d Cincinnati Ohio 1971
21 Keller GV and FC Frischknecht Electrical Methods in Geophysical Prospecting Pergamon Press New YorK NY 19bb
22 Kelly WE West Kingston Landfill An Evaluation of Its Effect on Ground-Water Quality Rnoae Island Water Resources Board Water Information Series Report 1975
23 Kelly WE Geoelectric Sounding for Delineating Ground-Water Contamination Groundwater V 14 No 1 1976 pp fa-10
24 Kelly WE Ground-Water Pollution Near a Landfill ASCE Environmental Engineering Division Journal V 10 No EE6 Dec 19b pp nay-nyy
25 Kelly WE personal communication January 1982
123
26 Kelly WE and OW Urish A Study of the Effects of Salt Storage Practices on Surface ana Ground Water Quality in Rhode Island NTIS FHWA-RI-RD-8001 1981 54 p
27 Kimmel GE and OC Braids Leachate Plumes in a Highly Permeable Aauifer Groundwater y 12 no 6 1974 pp 388-393
28 Klefstaa G Senalein LVA ana RC Palmauist Limitations of the Electrical Resistivity Method in Landfill Investigations Groundwater V 13 No 5 1975 pp 418-427
29 Landon RA Application of Hydrogeology to the Selection of Refuse Disposal Sites Groundwater V 7 no b 19b9 pp 9-13
30 Lang SM Bierschenk WH ana WB Allen 1960 Hyaraulic Characteristics of Glacial Outwash in Rhode Island Rhode Islana Water Resources Coordinating Board Bulletin No 3
31 LeGrand HE Patterns of Contaminated Zones of Water in the Ground Water Resources Research v 1 No 1 1965
32 Palmauist R and L Sendlein The Configuration of Contamination Enclaves from Refuse Disposal Sites on Floodplains Grouna Water v 13 no 2 1975 pp 167-181
33 Pinder GF A Digital Model for Aauifer Evaluation Techniaues of Water Resources Investigations of the US Geological Survey Bk 7 Cl 1970
34 Purushattam D Tamxe GR and CM Stoffel Leachate Production at Sanitary Landfill Sites ASCE Environmental Engineering Division Journal V 103 no EE 6 Dec1977 pp 981-988
35 Remson I Fungaroli AA ana AW Lawrence Water Movement in an Unsaturated Sanitary Landfill ASCE Sanitary Engineering Division Journal v 94 no SA2 April1968 pp 307-316
36 Rosenshien JS Gouthier JB and WB Allen Hydrologic Characteristics and Sustained Yield of Principal Ground-Water Units Potowamut-Wickford Area Rhoae Island USGS US Government Printing Office GS 67-324 1968
37 Roux PH and B Vincent Electrical Resistivity Evaluations At Solid Waste Disposal Facilities US Environmental Protection Agency SW-729 Cincinnati Ohio 1978
124
38 Salvato JA Wi lk ie WG and BE Mead Sanitary Landfill Leaching Prevention and Control Water Pollution Control Federation Journal v 43 no 10 Oct 1971 pp 2084-2100
39 Sawyer CN and PL McCarty Chemistry for Environmental Engineering McGraw Hill 1978
40 Stellar RL and P Roux Earth Resist ivi ty Surveys - A Method for Defining Ground-Water Contamination Ground Water v 13 no 2 1975 pp 145-150
41 Todd OK Ground Water Hydrology John Wi ley and Sons Inc New York 1959
42 Tolman AL Ballestero AP Beck WW and GH Emrich Guidance Mannual For Minimizing Pollution From Waste Disposal Sites US Environmental Protection Agency-500SW-677 Cincinnati Ohio 1978
43 Trescott PC Iterative Digital Model for Aauifer Evaluation US Geological Survey Open file report 1972
44 University of Rhode Island Academic Computer Center CalComp Contouring Manual
45 Warner DL Preliminary Field Studies Using Earth Resistivity Measurements for Delineating Zones of Contaminated Ground Water Groundwater v 7 1969 pp 9-16
46 White EF A Report to the Town of S Kingstown Utility Survey Engineering Corp 1967
47 Zohdy AAR A Computer Program for the Calculation of Schlumberger Sounding Curves Over Horizontally Layered Media Using the Method of Convolution US Geological Survey Denver
48 Zohdy AAR Eaton GP and DR Mabey Application of Surface Geophysics to Ground-Water Investigations Technidues of Water-Resources Investigations of the US Geological Survey Book 2 Chapter 01 Washington US Government Printing Office 2401-02543 1974
Introduction
Ground-water contamination of aauifers from municipal landfills
is a widespread problem Contamination of domestic supply wells and
neighboring streams has occured at the South Kingstown municipal
landfill which is located adjacent to Rose H i l l Road approximately
one mile nortn of Peace Dale Rhode Island (Fig 12) The polluted
neighboring wells have been relocated to their present locations to
remove them from tne leacnate plume (Fig 3) Fig 4 inaicates flow
patterns from the landfill which has contaminated streams to the
east and southwest of it The generation of leachate continues as
precipitation recharge and upgradient ground-water sources
infiltrate the refuse To effectively prevent or minimize
contamination from this landfill several remedial options are
available These w i l l be evaluated relative to the areas geologic
setting and hydraulic properties ground-water flow patterns
recharge characteristics and proximity to supply sources
The rate of ground-water flow out of the landfill into the
adjacent aauifer and flow patterns largely depend on tne hydraulic
gradient of the water table and the hydraulic conductivity of the
landfill and aduifer material The hydraulic gradients were
determined by monitoring water-table fluctuations in several wells
located around the landfill and elevation siting in stream
locations and elevations This information enabled a ground-water
map of the area to be developed from where flow patterns can be
developed assuming flow lines are orthogonal to contour lines The
ground-water map in combination with Knowing aquifer and landfill
N
^ooo
feet
Fig 1 Location Map
3
peoy ||H asoa
X ltbull
Alt
f c c
o
^ ^ o o f a
O OJ 83X1
o O
x o
seepage observation -t West
hole Landfill Area
Legend mdash landfill limit bull j--excavation limit r^-s stream copy WNWNEECSeuroSCSEN
monitoring well locations = = = unimproved road
A contaminated domesti supply well
D uncontaminated domestic supply well
feet
Fig 3 Supply Well Locations
5
a 03
N lo ^ gt
laquo c 2
mdash w
3
X o ^
3 O L
o CO
0 opound E bullo
0
co
c
o0
uj ^
0 o o c
o $ bullA
E c o
w
bullo t_hraquo9 O
_OplusmnJ ca
u
pro
ve I 51 H
bullo 0gt
UJ _c e poundbullo Mzbull w gt 0
laquorege cc
0gt -^^ o a5 raquobull bullo o sect 3 mdash laquoo o wcz _
3Ogt c $c o_ X
aw e 05 0 (0 3 bullo
o a 2 2 u
hydraulic properties and the subsurface geometry enable estimates of
ground-water outflow to be made Streamflow measurements were used
to verify these outflows Contamination levels using specific
conductance measurements as an indicator were measured in wells
streams and observation holes to help delineate the extent ana
degree of contamination An electrical resistivity sounding was
conducted in a known contamination zone
The primary objective of tnis study is to determine flow
patterns in the vicinity of the landfill ana recommend possible
actions to contain or minimize the impact of the contamination In
oraer to fully evaluate these goals the aforementioned parameters
were input to a computer model to produce simulated flow patterns
under different conditions The simulated present conditions were
matched with field water table and stream flow measurements to
calibrate the model A series of simulations were then run to
evaluate flow conditions before the excavations anaor landfill
existed Remedial measures such as reducing recharge to the
landfill and implementing a slurry wall to blocx off leachate flow
to endangered wells were simulated to evaluate their effectiveness
Based on this analysis recommendations are made as to how to
minimize leachate production ano best alleviate the immediate danger
of the contaminant plume spreading to unpolluted domestic supply
wells
background
The South Kingstown landfill is in a geologic setting that is
very similiar to the nearby West Kingston landfill This is located
about 3 miles west of the South Kingstown landfill and has been
studied to assess leachate effects on groundwater quality using
specific conductance as an indicator of contamination levels
(222ltt) Both sites were located in abandoned gravel Quarries which
were filled in with refuse to create the landfill
In the literature numerous authors have shown that the character
of contaminant plumes from landfills are largely dependent on the
local geology and geohydrology A study on Long Island (27) in
similiar glacial material illustrates that the Quantity of flow is
dependent on the hydraulic conductivity of tne aauifer the
hydraulic gradient and the vertical cross-sectional area of the
aauifer it flows through This is expressed as Darcys Law (41)
Q = KIA
wnere Q = flow quantity
I = hydraulic gradient
K = hydraulic conductivity of the aauifer
A = vertical cross sectional area of the flow area
Specific conductance was used as a contaminant tracer to show that
the plume from the landfill flowed downgradient and vertically
through the full thickness of the aauifer A study in Iowa (32)
indicates that the size ana shape of the contamination outflow from
a l a n d f i l l can be predicted from existing geohydrologic conditions
and that the horizontal shape of the outflow extends downgradient
8
from the source and parallel to ground-water flow lines Other
parameters which control the extent of the contaminant plume are
dilution and dispersion in the aquifer and the adsorption properties
of the aauifer material (31)
The amount of leachate generated depends largely on the amount
of water that infiltrates through the landfill to increase tne water
content of the refuse in the landfill The precipitation recharge
that percolates down through the unsaturated zone to the water table
moves in a vertical direction (35) Surface runoff soil moisture
storage losses and evapotranspiration account for tne precipitation
that is not transmitted tnrough the unsaturated zone of aeration
(3315) Upon reaching the saturated zone the water enters the
ground-water flow system Ground-water mounding has been reported
in landfills due to the decreased hydraulic conductivity of
compacted refuse relative to surrounding aauifer material (20)
Chemical processes within the landfill leachate outflow and
surrounding soil cation exchange capacity relative to water duality
of the surrounding aduifer have been studied in Pennsylvania (1) anu
in Delaware (5) A procedures manual for ground-water monitoring at
solid waste disposal facilities was developed by the US
Environmental Protection Agency (USEPA) (9)
Several reports have been written that investigate site
selection design criteria and remedial measures to correct
leachate problems (29) A survey of ground-water protection methods
for landfills in Illinois studies relationships to the water table
theory of liner installation and monitoring devices (13) Sanitary
Landfi11-Leaching Prevention and Control presents a review of
preventative methods such as means to minimize infiltration
interception of ground-water and other pollution control measures
(2 37) A study in Pennsylvania on actual measures implemented to
collect and treat a landfills leachate discharge presents a site
specific study (19) Leachate Quality Improvements After Top
Sealing1 shows that by minimizing infiltration at a landfill in
Connecticut the outflow leachate water quality can be improved
dramatically and contamination plume reduced significantly (6) The
most comprehensive reports on remedial approaches to upgrading waste
disposal sites and ground-water protection methods have been
compiled under USEPA contract (1542)
To assist in evaluating remedial measures the US Geological
Survey (USGS) computer model Iterative Digital Model for Aduifer
Evaluation was used It was originally developed as a model for
simulating two-dimensional aauifer problems (33) It had been
updated since its original development to accomodate different
options (43) This model has been applied to glacial outwash
regions in Rhode Island (717)
10
Description of Study Area
A map of tne landfill area (Fig Z) was obtained from tne town
of South Kingstown The excavation to the west of Rose Hill Roaa
the landfill area directly to the east and the presently operating
area to the east of the central stream comprise tne overall study
area This study will concentrate on the west landfill area whicn
has recently reached capacity and been closed to further dumping
This site received mixed refuse for the past 15 years The depth of
the excavation where the landfill presently exists was approximately
to bedrock in some places Tne exact depths of landfill material is
unknown
The landfill cover has been graded and sloped generally eastward
to convey surface runoff to the eastern side A sandy soil that was
excavated locally was used as tne cover material The northern
section has a vegetation cover and the recently filled southern
section has been seeded and mulched The six monitoring wells W
NW NE EC SE SC were placed by the town of South Kingstown to
provide water quality information
Referring to Fig 2 the west excavation stream drains the area
created by the excavation to the west of Rose Hill Road and flows
throughout the year The central stream drains a small watershed
area which lies to the northwest of the landfill and drys up during
part of the year These streams flow into the Saugatucket River
which flows throughout the year and is larger than the west and
central streams combined
11
The USGS Groundwater Map (18) was initially consulted to proviae
information on the ground-water flow patterns (Fig 5) and the
geology of tne area (Fig 6) The surficial geology borings and the
vertical geologic cross-section at the base of the study area
indicate shallow water table and bedrocic and a nearly constant
saturated thickness (18) Boring logs at the W well ana a point
approximately 150 feet south of it indicate glacial outwasn material
which is primarily sana with a trace of gravel over bedrock at a
depth of approximately 33 feet Borings at the east landfill area N
and S monitoring wells indicate the same aquifer material
(Appendix B)
The ground-water map developed by Hahn is taken as
representative of conditions existing prior to the excavation of the
I l andfill (18) This indicates water-table contour lines that run in i
a general northeasterly direction This means tnat flow was
originally in a southeasterly direction However contamination of
domestic supply wells on the west side of Rose Hill Road has
occurred (Fig 3) strongly suggesting that the original flow pattern
has been altered by the excavation to the west of Rose Hill Road and
the landfill to the east of it Domestic supply wells were formerly
located directly to the west of Rose Hill Road but were aoandoned
when they became contaminated from landfill leachate New wells
were located to the south and west away from the contaminant plume
of tne landfill In addition a well located at the northeastern
corner of the landfill was contaminated and a replacement located to
the east of Us former location on tne opposite side of the central
12
Legend scale 124000
mdash-40 mdashground-water contour elevation
Fig 5 Ground-Water Map
13
Legend feet
TILL
Fig 6 Geology Background Map
14
stream This second wel 1 also became contaminated Domestic supply
wells located near tne northwestern corner of tne landfill and
approximately 300 feet south of it nave remained uncontaminated
These well locations serve as an indication of tne extent of the
landfill contamination which is largely dependent on the groundwater
flow patterns To furtner investigate this problem and provide
substantial information on which to base the geohydrologic analysis
field studies of the area were conducted
15
Field Studies ana Procedures
A map of the lanafill and an aerial pnotograph of the area were
obtained A tracing of these maps superimposed upon another
delineates stream landfill and monitor well locations (Fig 2)
The field investigation concentrated on the west landfill area ana
its aajoining streams ana monitor wells The east landfill area and
the three monitor wells in that area are induced in the latter
phase of the study in oraer to expand the model area
A traverse which establishea tne monitor well elevations was run
using a Carl Zeiss level These were originally sitea in by the
town of South Kingstown using a local USGS reference datum number 40
(18) The wells of known elevations then served as benchmarks for
referencing adjacent stream elevations This in combination with
the depth to water table measurements at each well enables tne
water-table surface geometry of the area to oe visualized
Water-table measurements of the west landfills wells were recordea
over a ten month period to record fluctuations (Fig 7 Table 1)
The east landfill areas wells were monitored for a five month
period Using a given water-table condition a ground-water map was
developea of the area (Fig 4) This indicates an outflow from
the landfill primarily in a southeasterly direction and partially
in a southwesterly direction
Additional bedrock and water-table information was ootainea by a
seismic refraction survey at several locations along the landfill
perimeter A Bison Model lb70C Signal Enhancement Seismograpn was
used to maxe the surveys Lines were run (to a length of kOO feet)
16
17
w s p bdquo S bdquo s S S a laquolaquo _
s 2 8
V
r bdquo
3 s a
-R s
S
S 3
t
raquobullraquo
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5
K
r
~
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K
pound
7
S
bdquo3
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shy raquo S s
1 3 s 3 2 5 ^ bull
5 m
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R bull 5
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5 a 3 7 3 m
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2
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5
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5 a
^ a
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sj 5 Ml
3 a bull
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0)
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a j -
-3
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g S
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bull a
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2 s s 3 a bdquo s s $ Al s
(1) = $ s 3
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3 e 5 s N s S a - 3 = s s a 5
a s s - 3 S shy
4
0
a s
bdquo tfH
bdquo
3 a
bdquo
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e bullfl s i s s a s a
3 nt
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3 bull laquobull
2 a 7 3 a 3 a ^2
s mdash 5i o
bull bull
mdash
3 o
ss a
fc mdash
3 1-sect m ishy n
18
in both directions to provide a check and permit accurate estimates
of the depth to bedrockThe seismic results allow approximate
interpretations of the depth to the water table and bedrocK thus
permitting an estimation of the saturated thickness Ground
elevations at the location of the seismic surveys were determined
from a topographical map and field siting From this information
water table ana bedrock elevations estimates were made Bedrock
contours are listed in Fig 8 In addition a table which
summarizes the seismic refraction results for the unsaturated
saturated and bedrock layers velocities and depths at each survey
location is presented in Table 2
Scream gauging stations were established on the two streams
bordering the west landfill (Fig 9) Three stations were placed on
the central stream These provide information on the influent or
effluent condition of ground-water flow in the upper sections of the
stream and ground-water baseflow from an area adjacent to the
landfill into the stream (Table 3)
The stream gauging stations used were 90deg V-notch weirs The
weirs located in the SE and SW positions were placed in the
streamoea with a liner of plastic upstream to minimize underflow
The weirs located in the NW and E positions were cut to fit in
recesses of concrete culvert pipes Concrete plywooa interfaces
were coated with roofing cement to minimize bypass flow Upstream
water pressure and a snug fit hold the plywood sections in place
All weirs were implaceo according to AigtTM reouirements and flowrates
calculated using the standard 90deg V-notch formula (3)
19
N
seepage West observat ion Landfill hole
Area
Legend landfill limit excavat ion limit
copyWNWNEECSESC monitoring well locations
= = = unimproved road -- WNES-number
seismic refraction locations
-40shy approximate bedrock contpur elevation
feet
Fig8 Seismte Survey Location
20
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co CM o on on CO CM CTNVO VO co CM o on on Q gt_x rH oj on a oj on a - rH oner
rmdash on sr i i
M z Z
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1 gt fc^gtgt bullbull ^ ^ ^
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4-5 -0 _c^gt in in CO CO
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CO CM trade CO CM rH rH OJ co CM oj on Q ^ _ CO 3~Q-- n 45 Q mdash OJ OJ OJ C (0
1 11 3 nZ 2CO
gti gt gt CO CO CO ^-x m -s CO
rH rH ^ ro^^ bull gt bull ^ igt gt bullgt gtgt bull r O -Q 4Ji JJ O 5- JJ O pound- ^ O 4) oj o on (0 CO
3 bullH CJ O O in 3 bullH CO Cmdash VO on 3 pound-laquo H CO o n in inco co o n ma- r co g^ 5sect^ o
o rH on oj O bull- rH ONCO L O_ rH OJ VO M
rH bull rH =t rH bull - OJ T CO CO M CO 4-gt rH CO -U rH CO 4-) s
uits
CO 4-gt 4-5 T3 gt CM gt CM gt CM cc CO CO CO
3 3gt oa tlp^ CO O CM O gt 4J O 40 i 3 r+ k C pound JS
CO pound
^^ s -bullgt cmdash on poundZ VO CTI trx 4J 4J 4J
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Q Q QON^ Q bullH Q^
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i gtgt rH oj on gt tgtshyCM ^ cO^-s CO ~ CO
CO CO J X fc^_ bull^gt bullgtgt bull gt gtgt bull gt CO
j_ jJ O pound- Jj -P O Li deg =fObullH co on f- ^ 3bullH CO CO O in 3bullH CO
g^ -^2
poundsect HO
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3 CO in in in in in in co o n co o n
o -^ r oj in O rHCO CO rH bullrH bull rH =T OrH bull rH OJ f-CO 4J bull- CO 4J rH O0) J-)
gt CM gt CM gt CM 4J
CO N_^ m^
bull OJ
t t poundshyCO CO CO CO rH J3 gt r-t oj on gt r-i oj on gt gt r n o j o n
lto co lto CO T bull ii-4 laquomdash bullmdashH
bullo CO L L 0)
CM CO cc
21
N
545-594
seepage observation
hole West Landfill
0NE I47-509
Area
Weir 45
i487-531
0 EC Al3-467
Legend bullmdash landfill limit -bull---excavation limit r-s stream
copy WNWNEECSESCSEN monitoring well locations
= = = unimproved road
Weir location and elevation
feet
Fig 9 Weir Locations and Wate r Level Ranges
22
JT NO
S shy S
O
bull ry m
oa
NO
(M raquo 1 03 or NO m
JT O O raquo
O NO 03 (j
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mdashraquo 3 M
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H fy (NJ
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7 raquo
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i in
i ru
i 0 rsi -or^
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03 raquo
1 O3
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i O
i ^
shy
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r-laquo
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pound raquoraquo O)t o gtz
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1 pound OJ
3 oi g bull
pound
1 pound laquolt bull
3 bull o a
pound
5 laquo15
f bull 3 Jl s
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23
A field study to determine the infiltration capacity of a
section of tne landfill topcover was conaucted A modified version
of a double ring infiltrometer was used to study infiltration rates
(4) The cylinder diameters useo in this study were 8 inches and 18
inches A constant head of 6 in was maintained in the
infiltrometer and rates of infiltration were determined Tnese
results and an analysis of surface infiltration into the landfill
are included in tne analysis and discussion section
Specific conductance levels in the monitoring wells in the
streams bordering the landfill and at observation holes near the
landfill were measured (Fig 10) This is a good indication of the
mineralization of water (39) Specific conductances were measured
intermittently over the ten month period to develop a picture of the
extent and degree of contamination in the wells (Fig 11 Taole4j
and in the surface contamination monitoring locations (Fig 11
Table 5) A comparative standardization of the Beckman (short and
long probes) and YSI specific conductances is in Appendix C
A surface electrical sounding using the Schlumberger array was
conducted adjacent to Rose Hill Road at the R-l location (Fig 12)
in an attempt to delineate the vertical extent of the contamination
zone Well W was used as a centerpoint and a reference for
water-table depth pore water conductivity and depth to bedrock A
Schlumberger array electrical resistivity sounding was also
conducted in an uncontaminated area at tne R-2 location (Fig 12) to
provide a comparison background interpretation A seismic
refraction survey N-4 was conducted at the same location (Fig 8J to
24
N
excavat ion
Seepage West observat ion Landfill hole
Area
Stream 1 Seasonal observation 0 EC
hole
East Stream2
Legend sw Weir landfill limit j--1--^ excavation limit
copyWNWNEECSESC monitoring well locations
== unimproved road
feet
Fig 10 Surface Contamination Monitoring Locations
25
8000T
7000
O bull U) W6000
Legend
0 sc A NE O W
A SE O N W
a EC
1 O N D J F M M
Time months Flg11 Flucuatlon In Specific Conductance in Wells
26
Table 4 Specific Conductances in Wells (pmhoscm at 25degC)
West East Landfill Landfill
Date NW NE EG SE W SC N E S
81581 851 938 236 2356
102981 171 3268
11381 3268
111081 304 988 1100 258 3800
111481 426 2736 1216 186 4560
111781 304 3610 433 389 4560
121981 380 1406 129 103 380
1982 160 152
31582 274 760 1064 61 334 8000+ 182 53 84
52182 450 1500 1125 112 712 8000+ 175 255 150
52282 425 1320 1200 110 850 180 320 170
27
O
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3 iCM 4J
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pag
se
rva
t
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t CM0gt s o o o in rA n ^o oo in tmdash oo 0gt zr =r a- JT JT$_
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vgtO ^D O ^^ ^O CO ^^ ^^ JJ 2 4) rH rHCO t
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4)bull
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^ ^ ^ ^ H r H r H r H r H rH r H C O r H C O a O C O a O a O C O C O r H i H r H CO OO - gt 0 0 ^ - gt ^ raquo - ^ ^ 1 - gt ~ gt - C O C O O O
U ^ raquo ^ - ~ raquo O ^ ^ O t ~ C O r H - r r ^ - ^ ^ JJ r H C M v O r H r H r H r H r H C M C M r H i n c r gt rH CO CM gt laquolaquo - - -^ bullmdash mdash bullraquoraquobullgt -v -v ^^
~ v O r H r H r H r H r H r H r H r H lt M C M C M CM O O r H r H r H r H r H r H r H r H r H r H r H r H rH
in rH cmdash
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CO vO
41 rH CO
CTgt rH raquo CM rH
cn CO
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tmdash fshy
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tmdash Cmdash
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28
excavation
West Landfill
Area
Legend bullmdash landfill limit -bullbull--bullexcavation limit r~~s stream
copy WNWNEECSESCSEN monitoring well locations
= == unimproved road
electrical resistivity sounding
feet Fig12 Electrical Resistivity Sounding Location
L
29
allow estimates of depth to water table and bedrocic to be made
Soundings were carried out to 500 foot electrode spacings to insure
that hredrock was penetrated and to facilitate interpretation These
results and a discussion of the soundings interpretation are
included in the analysis and discussion section Schlumoerger
resistivity soundings were made using a Soiltest R-bO unit
30
Model Development
The USGS Iterative Digital Model for Aauifer Evaluation was
usea to develop steady state flow models of the study area (43) A
flow chart of the computer model and a brief explanation of the
subroutines usea is presented in Appendix D The stream locations
elevations and aauiferlandfil1 geometry and hydraulic properties
were input to the model to compute head values at each 200 foot
grid spacing node (Fig 13) The input data which is for the
existing excavation and landfill conditon is listed in Appendix E
The head values that are computed at each grid space are in turn
loaded into the CalComp plotting routine (44) where a grid spacing
is setup with the computed head values at each node The contouring
program linearly interpolates between these head values and
generates a contour map The computer simulated ground-water
contour map for the excavation and landfill is presented in Fig
14
The streams in the model generally serve as controlling boundary
conditions When using computer simulated geohydrologic models of
an area choosing the boundary conditions for the model that are the
same as prevailing conditions in the field is a critical step in
model development Extending the models boundaries to areas in the
field that have a minimum influx of ground-water across them
simplifies the proolem of calculating fluxes from outside the model
area The eastern boundary is bordered by glacial till which has a
low hydraulic conductivity estimated to be 67 ftday(2) This
contrasts to the high hydraulic conductivity of glacial outwash that
makes up the model area of approximately 107 ftday(3036j
31 N
o 9
bullO O
32
33
The Saugatucket River serves as the controlling boundary on the
east A small drainage area directly to the east of it provides a
minimal influx
Beyond the moaels northern boundary the glacial outwash valley
extends to the base of a till covered h i l l on the western half ana
on the eastern side extends along the Saugatucket stream Due to
the relatively large drainage area that lies upgradient from the
northern boundary a recharge flux eduivalent to 10 inyr over the
drainage area on the till hill and outwash area north of the model
area was input as underflow (Fig Ib) Part of this was input at
each northern boundary node Till has a lower infiltration capacity
than outwash so more of the precipitation w i l l be transmitted as
overland runoff resulting in a lower ground-water baseflow The 10
inyr of recharge that results in a ground-water inflow from the
combined till and outwash region represents an estimate that is
smaller than the 14 inyr recharge for glacial outwash areas in
Rhode Island (25)
The glacial outwash valley extends beyond the western boundary
No significant ground-water recharge flux was estimated at this
boundary A relatively low ground-water gradient exists to the west
of this which does not provide a significant flux across this
boundary Tne southern boundary is basically the outflow region for
the area and therefore would not reauire any ground-water flux into
the moael area across this boundary This boundary was set south of
the point that the streams in the model merge together Therefore
the streams which lie to the north of it are the controlling
34
scale 124000
Fig 15 Northern Drainage Area
35
boundary conditions The flux out of the downgradient outflow
region approximately eauals the influx from precipitation recharge
and boundary influxes
When tne stream configuration in the moael area are reviewed it
can be seen that they comprise a large portion of the boundary
area The screams can act as sources or sinks for water in the
model thus providing to and removing water from the aquifer The
leakance option was used in the model which provides for a confining
bed and aouifer area beneath the stream to be input
The leakance is defined as the hydraulic conductance of the
streambed divided by the streambed thickness which in this case is
taken as 1 foot The leakance value at each streambed node
restricts the flow between the aduifer and the stream The
streambed hydraulic conductivity is typically 01 the value of tne
hydraulic conductivity of the aduifer (717) The value 107
ftday was used for a streambed conductivity based on a value of
107 ftday for the aquifer The aduifer and stream hydraulic
inputoutput exchange at eacn node is calculated by initially
finding the difference between the initial field stream head
elevations and the computed head elevation values at the
corresponding nodes This head value is then multiplied by the
(Leakance value at each node) x (stream area of each node)
Therefore if the aduifer head was lower than the stream head the
stream would act as a source of water for the aquifer and vice
versa
36
Tne leaxance input at each stream node is the ratio of the
actual field streambed area in each node to the area of each node
which is 200 ft x 200 ft = 4 x 104 ft2 The west
excavations stream width is approximately 3 ft central 4 ft and
east 5 ft Therefore if tne west stream traverses the node
directly without meandering it presents a leakance of 3 ft x 200
ft4 x 104 ft = 015 Leakance and streamhead values were
input at each node to set up the stream flow parameters in the
models
A recharge value of 14 inyr over the entire area was input at
each node This represents a value of precipitation that is
transmuted into tne ground-water rather than being directly
evaporated evapotranspired through plants or overland flow
runoff The precipitation recharge flow from the stream into the
aauifer and boundary fluxes provide the model witn input flow
parameters
From analyzing the available information it was determined that
the study area lies within a glacial outwash area with a relatively
shallow bedrock The seismic survey around the landfill generally
indicates a depth to bedrock below the land surface of approximately
29-43 ft with corresponding saturated thicknesses of 19-33 ft as
seen in Table 2 This agrees with borings from tne USGS groundwater
map in the stuuy area (18j The seismic survey was run at a low
water table condition which was several feet below the high water
table level (Fig 9)
37
High water-table saturated thicknesses were used to develop
model parameters For the purpose of this model study the saturated
thickness was set at 30 ft except in the vicinity of well W where
there is a bedrock high (Fig 8) At this location a high water
table saturateo tnicxness of 8 ft was estimated In tne vicinity
the seismic survey was conducted the bedrock elevation at this
location is the highest and the saturated thickness the least Tnis
can be seen by an east-west cross section of tne landfill (Fig 16
The boring log for well W indicates a sand trace gravel outwash
material (Appendix B) Boring logs at the eastern landfill area N
and E indicate similar material On this basis the hydraulic
conductivity was estimated at 107 ftday (3036) Witn the
exception of the landfill and the bedrock hign areas the
transmissivity values were set at 107 ftday x 30 ft = 3210
fto day From the literature the hydraulic conductivity of the
landfill material was estimated at I ftday (19) The
transmissivity of the landfill material in tne nortnern section was
estimatea at 1 ftday x 30 ft = 30 ft^day or approximately two
orders of magnitude lower than the outwash In tne landfills
southern section the original excavation was not as deep as in the
northern parts The landfill material was estimated to makeup only
one half tne saturated depth the remainder being the original
glacial outwash material (Fig 17) Therefore the transmissivity
at the southern end was estimated at 15 ft x 107 ftday + lb ft x
1 ftday = 1620 ft^day These values were graded into the 30
ft^day values at the landfills northern halfway point These
38
were input as transmissivity values to the model at their respective
locations This model did not use the water taole option so
water-table fluctuations did not affect the transmissivities
39
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40
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Model Calibration
A simulation was run using the initial estimates of stream
parameters aquifer and landfill hydraulic conductivities
transmissivities boundary and recharge conditions to approximate
water taole conditions in tne fiela Initially the existing
condition of the excavation area to tne west of Rose Hill Road and
the landfill to tne east were modeled in order to calibrate the
model to current field conditions as shown on Fig 4 The simulated
well values (Fig 14) fall within tne range of field values (Fig
9) The resulting contours also provide an approximate matcn This
can be seen by comparing Fig 4 with Fig 14 An additional check
was to match the flow loss and gain in the streams between tne weirs
in the central stream which w i l l be discussed later The
simulated flow value from the excavation drainage stream is the same
as that measured at the SW weir location Having calibrated the
model by approximately matching well water levels nead contours
and scream flow values different field conditions and possible
remedial measures can be simulated
When the model grid was laid out over the study area as viewed on
Fig 13 the stream configuration rarely traversed the grid nodes near
their central axis When the stream locations were input to the
computer the information was documented as crossing the central axis
of the grid nodes The result of this is a slight aberration when
the actual stream configuration is laid over the computer graphics
head contour output The streams dont always cross the groundshy
water contour at the logical location Rather than modifying the
actual stream configuration to adjust then to the computer output
their actual locations are presented
42
Simulations
i The primary focus of the computer modeling is to analyze flow
patterns under changing conaitions in the near vicinity of tne raquo
landfill The study areas overall flow patterns as they exist
today are first presented in order to realize the lateral east-west
head contour lines between the stream that directly borders the
landfill on the east side and the SaugatucKet stream (Fig 14)
This indicates a general southerly flow direction in that area As
different conditions are modeled these contours generally maintain
their east-west orientation In order to facilitate interpretation
of flow patterns in the near vicinity of the landfill flow patterns
to the west of the stream that borders the east side of the landfill
r are presented in the subseauent models
L- Natural Conditions
The results of modeling the original natural conditions are
shown in Fig 18 The excavation and stream to tne west of Rose
Hill Road and tne landfill did not exist in this simulation The
southwestern boundary consists of a drainage stream that was
delineated using an aerial photograph and stream elevations were set
using the topographical map The USGS ground-water map (18) was
used to estimate head values between the west excavation and north
streams These were input to the model as constant heads on the
models western boundary The resulting simulation generally matches
the southeasterly flow direction that is indicated on the
ground-water map (Fig 5)
A3
Legend
x-^- stream 400 = = = unimproved road
I f ee t
Fig 18 Natural Conditions
44
Excavation Without Landfill
The condition of the excavation to the west of Rose Hill Road
with its resultant drainage stream without the landfill was modeled
next (Fig 19) The extent of the excavation ana the location of
the new drainage stream were delineated using the aerial
photograph The west stream elevations were sited in the field and
used in the model The concept of a confining streamoed layer was
excluded in tne excavation drainage stream under the concept tnat no
significant organic layer had been built up within the 25 year
period that the excavation had been initiated Head values between
the west and north stream boundaries were interpolated and input as
constant head values on the northwestern boundary The west
excavation drainage stream creates a condition that alters the
natural ground-water flow patterns by creating a more southerly flow
condition the drainage stream providing a more immediate surface
outflow in that area
Landfill Without Excavation
The hypothetical case of a landfill without the excavation was
modeled next (Fig 20) The low hydraulic conductivity zone of the
landfill changes the natural flow conditions and creates noticeable
mounding This is evidenced by the decreased spacing of the head
contour lines and deviation from the lateral contour lines of the
natural conditions and higher head values (Fig 21)
45
Legend
excava t i on s t ream
400 unimproved road
f e e t
Fig19 Excavat ion without Landfill
46
Legend
landfill limit
bull - s t ream 400 copy WNWNEECSESC
monitoring well locations f ee t bullbull-bull=bull unimproved road
Fig 20 Landfill without Excavation
1
oin CM
bull
m u
0)rf
oO
bullo 9
bullo 9
o rf o o CO 1
lt0inO O
T ^ogt
c o
47
o9 aI 0)
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bulla caj
CM
UO|IBAraquo|
48
Landfill ana Excavation
The condition of tne existing landfill and the excavation with
the dam is the next condition modeled (Fig 22) The ground-water
elevations used to calibrate tne model correspond to an actual high
water table condition Between the NVJ and pound weir a streamflow loss
of approximately 102 gpm occurs aoout 60 percent of this flow is
lost at the dam site which maintains a head of b-6 feet over an area
of approximately 1800 feet^ This approximates a field value of
1144 gpm influent to the aduifer between the NW and E weir on ]2
December 1981 (Table 3) From the E weir to the SE weir a net
increase in flow occurred of 74 gpm which corresponds to field
increase of b62 gpm
The surface runoff from tne landfill flows primarily toward tne
eastern side of the landfill Increases in water-table elevations
on the eastern side after heavy rains such as the 11 November 1981
storm indicates that this runoff increases outflow gradients to the
stream and therefore increases streamflow Surface runoff input is
not modeled which explains in part why field stream inflow values
are slightly higher than model predictions especially for periods
after a storm has occurred The flow from the SW weir located at
the southern end of the excavation represents drainage outflows from
that area The net flow calculated in the model was 140 gpm
which approximates field conditions of 1642 gpm on
December 9 1981
49
d f l f reg N E
shy
Legend
landfill limit -bullgt-bullgt- excavation ^-N_X- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road
-40mdash approximate groundwater contour
400
feet
Fig 22 Landfill and Excavation with Dam
50
The modeled flow patterns suggest how the various contamination
zones around the landfill have developed to their present state
They indicate a flow to both the southeast and southwest on their
respective sides of the groundwater divide Evidence of a
southwesterly contaminant flow is presented when the continued high
specific conductance contaminant level in tne observation seepage
hole is realized (Table 5 ) In addition the specific conductance
increase in the west excavation stream is evidence of an influent
contamination flow
Contamination flow to the eastern and southeastern side of the
landfill is obvious High specific conductance levels in the wells
on the eastern side (Table 4 ) a specific conductance increase
between the E and SE weirs (Table 5 ) and contamination in the NE
domestic supply well (Fig 3) present conclusive evidence of
contamination to the eastern side of the landfill
An anamalous condition that exists is a domestic supply well
located approximately 300 feet due south of the landfill remains
uncontaminated (Fig 3) Flow patterns indicate that contamination
would be transported from the landfill south to this area
(Fig 14) One explanation is that a pocket of clay at the southern
end of the landfill area was discovered in the original excavation
for the landfill (lt6) This evidently prevents leachate from
reaching this wells radius of influence
51
Summer Conaitlon
As described earlier during dry months of the year the stream
that normally borders the northern and eastern side of the lanafill
may dry up as far as a point southeast of the E well Tnis
condition existed from the 15 August 1981 to the 27 October 1981
period when streamflow commenced in the northern part of the stream
yet did not overflow the north dam until 17 November 1981 This
created the present day continuous flow condition throughout the
stream These summer conditions were modeled by removing the stream
above the aforementioned location while other conditions remained
the same (Fig 23) Summer condition well water levels listed in the
model generally match field low water table conditions (Fig 9)
Because there is no stream upgradient from the landfill to provide a
stream head and infiltration through the streambed groundwater
runoff from the area north of the lanafill is the controlling flow
input In these moaels an average recharge of 14 inyr was used
which represents a yearly average The summer recnarge conditions
are prooably lower given the effects of decreased rainfall and
increased evapotranspiration during the summer months A domestic
supply well whicn exists northeast of the landfill (Fig 3) nas a
greater potential to be contaminated from the lanafill at tnis time
than when the stream is flowing Flow patterns from the landfill
are such that during an upper stream no-flow condition groundwater
flow patterns are more in an easterly direction than in a
southeasterly direction The stream would act as a source of
infiltrated water upgradient from tne landfill and provide a
52
I ^N gt i I i j i -r- -bull- bullr -T- t- -r- i- TJ JV
bullbullT laquo ^ O - laquo bdquo xi cshy
H r^~ I -~- --^ X- = mdash x^ N
^--^ A bull O^NW -v - gt-bull Ni i I _____mdash - bull laquo l - mdashmdash 1 deg I ^ltv I C
I reg NE A
Js bull vbull A ~ - v T gt- ^ ix - N
-5Z- | N TfS lV I -bull bull iA i gt gt I ^ bullr-Ky L bull 1 _- copy]wgt-- - bull- mdash - - shy
= r Y ~mdash ltmdashA A
^^-lt A _ - - - - bull Hmdash - reg EC x ^-mdash mdash I ---mdash_mdash -t-V-^N - y
I- -bull - r x i X
V ^ 7 I -v (^~~^^r ^^^
sc Emdash-bull vV JI - - - ~ r )N y- -
X - bull r bulllt
^bull^ y y Jlaquo^ - -lt shy
T s^ lt^ ^ +^-b (
X
Legend
landfill limit j-j-bullraquobull excavat ion gt^ -x- s t ream
reg WNWNEECSESC monitoring well locat ions
= == unimproved road fee t
Fig 23 Summer Condition
400
53
constant head across tne northern section of the landfill This
would tend to orient the flow in a more southerly aowngradient
direction In addition the stream which flows adjacent to the
northeastern well could provide a source of infiltrated clean water
to it which would minimize the possible contamination from landfill
leachate
Without Dam
During tne spring scream flow condition the dam failure which
occurred between the 15 March 1982 ana 9 April 1982 monitoring
periods decreased flow to the aauifer and landfill This eliminated
the 5-6 foot head difference over a 19000 ft^ area which had
created a larger area and elevation head for infiltration to occur
The condition without the dam was modeled by reducing the area
encompassed by the dam to a 4 foot wide stream channel thus
reducing the leakance value at that node (Fig 24) The flow change
from the stream to the aduifer between the NW weir and E weir
reduced the model flow loss to 50 gpm Tnis corresponds to the 9
April 1982 monitoring period which indicates a 30 gpm loss
As compared to the previous flow loss in the upper stream
sections to the aauifer the 21 April 1982 and 22 May 1982
measurements between the NW and E weirs indicate a flow gain The
streamflow conditions have changed from an influent
stream-to-aauifer condition to an effluent aduifer-to-stream
condition that increases flow downstream
54
Legend
landfill limit j--i--i- excava t ion x-gtmdash^- stream 400
copy WNWNEECSESC monitoring well locations
= == unimproved road f e e t
Fig 24 Landfill and Excavation without Dam
55
Analysis and Discussion
In order to fully understand flow patterns and Quantify leachate
outflows at the landfill it is necessary to arrive at an estimate
of flow inputs from precipitation ana upgradient sources In the
following analysis it will be demonstrated that the rainfall input
to the landfill is the factor which controls leachate generation A
calculation using the H inyr recharge over the area of the
landfill was made to estimate the leachate outflow due to rainfall
infiltration An estimated 134 gpm is generated from the entire
landfill area Simulation of the existing conditions (Fig 24)
indicates a groundwater divide in the landfill is located
approximately at the western third Therefore approximately 23 of
the generated leachate flows to the eastern side of the landfill or
9 gpm The effect of the flow input from the upgradient stream is
evident when tne summer condition witnout the stream is viewed
(Fig 23) Without the stream to infiltrate the landfill and the
recharge and northern boundary condition as the flow inputs the
head at the northern end of the landfill drops about 5 feet from its
previous value A flow pattern from the north central part of the
landfill to the eastern side indicates a 12 feet head difference
with recharge - but with the upgradient stream a 16 foot head
difference occurs Considering the transmissivity change the
stream would increase the leacnate outflow from the landfill
approximately 43 under a low water table stream influent condition
to the aauifer This would increase leachate outflow to the east
side to approximately 129 gpm This value approximates the
56
outflow at the SE weir location during the summer monitoring period
when the upper stream was not flowing (Table 3) The outflow from
the western third of the landfill whicn lies to the west of the
ground-water divide would be approximately 63 gpm
Realizing the importance of infiltration to tne landfill as a
major influence on the generation of leachate an analysis of this
w i ll be discussed An estimate of infiltration was made using the
precipitation recora for October ana November (Appendix A) During
this time period a minimum of direct evaporation ana
evapotranspiration occured and the grouna is not yet frozen The
top cover over the lanafill is generally 05 ft to 2 ft of local
sandy soil and subsoil availability determined what was used The
top of the landfill is at an elevation of 92 ft as compared to the
ground surface at well W which is at an elevation of 76 ft
(Fig 25) This compares to the well W water level which is at an
elevation of approximately 52 ft This creates a long path for
infiltration through the unsaturated zone The topcover generally
slopes eastwara at a grade of 2-5 The west side maintains a
relatively steep slope of 10-15 ft drop within 50 ft ana the north
and eastern slopes have a more gentle slope of approximately 10 ft
within 100 ft distance An unlined surface arainage swale channels
surface runoff from the northern section of the landfill past the
NE well to the eastern side ana low area in the vicinity of the E
well This has a drainage swale to an area near the stream but
doesnt directly connect to tne stream A poorly graaed drainage
swale exists on the landfills left side The landfill material has
57
excavation
seepage observation ^
hole
Legend bullmdash landfill limit -^--excavation limit r^s- stream
copy WNWNEECSeSCSEN monitoring well locations
--- unimproved road O location of amp Inf i l t rometers O
feet
Fig 25 Infi ltrometer Locat ion and Drainage Feature
58
been placed in 10-12 ft cells and covered with 1 ft of soil at the
end of each day The material has settled differentially creating
areas for depression storage
An estimate of the percentage of precipitation that infiltrates
the landfill was made from precipitation records recorded well
elevations and an estimated specific yield for the landfill
material The volume of water that infiltrated should eaual tne
specific yield multiplied by the well water level rise Several
recharge periods were studied using this relationship Once the
percentage of precipitation that has infiltrated is determined the
percentage that is translated into runoff is simply the remaining
percentage if evaporation is neglected
From the literature for a slightly inclined slope of 2-5
typical runoff coefficients range from 10-20 in either sandy or
heavy soil (16) The landfill cover is generally sloping to the
east which creates a long path (approximately 400 ft) before the
runoff reaches the steeper slope on the eastern side of the landfill
of 15-20 The long drainage distance creates a greater time for
rainfall to infiltrate Another consideration is the actual
capacity of the soil to conauct water into the soil which was tested
in the field using double ring infiltrometers An average initial
percolation of 8 mmhr the first hour and a subseauent rate of b
mmhr occurred (Fig 26) The 8 mmhr rate compares well with
other sandy soil infiltration rates (14) Therefore if the
intensity of the rainfall exceeded a 5 mmhr rate for several hours
59
CO + 09 o
E o
CO
o Z pound C
O
C9
o DC
CO
CD CM
ogt CO N- to -4 CO CM
jq tuu i U O | raquo B J J | | J U |
60
on a poorly drained surface the additional rainfall would be
translated into runoff because the soils infiltration capacity had
been exceeded
The initial 8 mmhr infiltration rate was due to the pore spaces
in the sandy soil being filled and the subsequent 5 mmhr rate was
percolation into the low permeability landfill material The tests
were conducted in November assuming a minimal evapotranspiration
and the field capacity of the sandy soil had been maintainea
The W well was used as representative of the water elevation
changes in the landfill because it is directly adjacent to the
landfill 900 ft distant from the upgradient stream This minimizes
the effect of infiltration from the stream and maintains a high
contaminant level During periods of high runoff conditions excess
surface water ponded in a poorly graded drainage swale on the west
side and directly adjacent to the landfill This influenced the W
well at a time the contamination level dropped (Fig 11) Before
this occurence in mid-December the rise of the W well closely
matches that of the SC well and a background well SK6 which is
located outside the study area (Fig 7) Therefore it was analyzed
as a valia indication of the water level rise during the mid-October
to mid-December period The monitoring of the SC well was
intermittent due to inaccessaoility because of 10 ft extensions
being placed on the well as the refuse was being filled in arouna it
61
A high rainfall period from 14 November 1981 to 1 December 1981
was chosen for the initial study period The effects of
evapotranspiration were neglected due to the cool temperatures
experienced at this time Therefore it was assumed that the field
capacity haa been reachea and tnat any additional input to tne
unsaturated zone would result in direct percolation to tne saturated
zone During the time period 14 November 1981 to 22 November 1981
029 ft of rainfall fell and the well W rose from 488 ft to 493
ft - a 05 ft increase During the next 8 day period there was no
precipitation yet the W well continued to rise to 4972 - a 042 ft
increase The slow percolation of water through the landfill
material would account for the latent rise in the well water level
From previous reports a specific yield for refuse was estimated to
be 028 (1920) This value is dependent on the original compaction
of tne material age and resulting consolidation
During the 14 November 1981 to 1 December 1981 period 029 ft
of rain fell and the well increased 092 ft The following
relationship is used to evaluate the infiltration value and runoff
I = (Sy) h
Sy = specific yield
h = well rise
I = volume infiltrated
I = (028) (092 ft) = 0261 ft
62
The difference between the precipitation and the infiltration is
the runoff (assuming no evapotranspiration) Therefore 029 - 026 =
003 and furthermore 003029 - 13 runoff This corresponds in
the literature to a typical runoff coefficient for an inclined
surface of 2-5
Analyzing a longer precipitation period from 18 October 1981 to
1 December 1981 a net precipitation of 043 ft (accounts for
evaporation) occurred less 10 for runoff or 039 ft infiltrated
This results in a 139 ft elevation increase The well water level
actually increased 132 ft shy only a 5 deviation from the
calculated
From tnis investigation it is seen that a large proportion of
the precipitation has the potential to be transmitted into the
landfills saturated zone Exceptions are wnen heavy precipitation
periods exceed the soil percolation capacity frozen ground prevents
infiltration and direct evaporation and evapotranspiration recycles
the ponded surface water and infiltrated soil moisture back to the
atmosphere In retrospect water temperatures within the monitoring
wells could have been measured to indicate thermal effects from the
landfill on ground-water temperature Ground-water temperatures
were assumed to be 50deg F (9)
63
Specific conductance measurements serve as an indication of
contamination levels These measurements are used to trace leachate
movement which represents ground-water flow patterns Factors which
must be considered when monitoring pollutants are the attenuation of
the leachate contaminants which occurs both in the zone of aeration
and the saturated zone The former is a more complete process
Dilution dispersion and cation exchange are the primary factors
involved in decreasing leachate concentration in the saturated
zone The glacial outwash materials of southern Rhode Island do not
have a cation exchange capacity or a high buffering capacity so
attenuation is simply by dilution and dispersion (22)
The NW well consistently exhibits relatively low specific
conductance levels even though it is in landfill material It is
situated in a drainage swale and ground water elevations range from
543 to 5944 This is several feet below the upgradient stream
elevation of 64 feet which is less than 400 feet away The bottom
of the wellpoint is at an elevation of 5312 feet well into the
landfill material Infiltration from the stream to the landfill has
occurred at this location
The W well is situated on a bedrock high adjacent to the
landfill approximately 900 feet from the upgradient stream and its
water level is higher in elevation than the excavated pit (West
Observation Hole) which is 300 feet directly west The W well
maintains a contaminated level A poorly graded drainage swale to
the west of the landfill provides areas for extensive ponding and
infiltration to occur which explains the drop in conductance after
a high runoff period
64
The SC well is located in landfill material and has a
conductance of over 8000 umhos This indicates that leachate is
undiluted The oottom of the wellpoint is at an elevation of 389
feet which is situated in the landfill material
High specific conductance measurements in the west observation
hole and well W and their relative elevations indicate a
west-southwesterly flow direction from the landfill Infiltration
recharge and leakance from the stream into the landfill provides the
necessary elevation to cause outflow in this direction
Contamination from the landfill to the surrounding streams is
evident (Table 4) During the period 15 August 1981 to 27 Octooer
1981 there was no flow in the stream that Borders the northern and
eastern side of the landfill until a point just south of the E well
was reached High specific conductance levels in the EC and NE
wells were recorded (1000 jjmnos) At a point directly east of well
EC a pool of water existed that was relatively uncontaminated which
is designated as the East Stream] location (Fig 10) At a point
just south of that (East Stream^ polluted water in the streambed
was flowing at a low rate This was measured at the SE weir
location and which had a high conductance also Flowrates varied
between 6 and 23 gpm and specific conductances were over 350
pmhos This low water table condition flowrate is the baseflow from
the eastern side of the landfill and indicates a southeasterly flow
direction from it
Streamflow commenced in tne northern part of the stream 21
October 1931 and the north dam oegan to f i l l Stream specific
65
conductances were low indicating a clean water source Tnis
continued until 17 November 1981 when the dam overflowed ana flow
throughout the east stream began A weir was placed at the Rose
Hill Road NW location and was compared to flowrates at the SE
location Flowrates decreased and specific conductances increased
between these two locations
To further investigate the condition of a lower flowrate
downstream than upstream an intermediate weir was placed at the E
weir location (Fig 9) This snowed tnat the stream from the M
weir to the E weir was losing water to the aauifer (influent
condition) and gaining water at the SE weir (effluent condition)
The condition of a net loss of water between the NW and SE weirs
remained until 19 December 1981 when a snowmelt rain condition
caused increased surface runoff and a net increase in flow at the SE
location Upon analyzing the March and April 1982 streamflow
conditions the expected case of a net ground-water pickup from the
E to SE weir continued The explanation for tne initial net loss of
ground-water is the fact that the leakance from the upstream section
was being discharged into aauifer storage to raise the ground-water
table to an eduilibrium level Upon reaching a high recharge
equilibrium steady state condition any additional input will
eventually be transmitted as baseflow out of the landfill and a
downstream net pickup will occur A hign water table condition
prevailed during the January through May period maintaining this
condition In April the north dam broke through reducing the head
in that area by 4-6 feet The 9 April 1982 monitoring revealed that
66
an influent condition remained between the NW and E weirs but at a
reduced rate The 21 April lower stream flow condition shows a
small pickup of water between the NW and E weirs indicating the nigh
water table and low stream flow conaitions combined with the absence
of the dam had changed the conditions to an effluent condition
This was evident in the May monitoring period
Evidence of contamination on both the western and eastern sides
of the landfill supports the existence of a ground-water divide in
the landfill The west stream which drains the excavated area to
the west of Rose Hill Road shows contamination pickup between its
northern section and the SW weir The W well and ooservation hole
indicate high contamination levels which reinforces the concept of a
contaminant outflow to tne west excavation stream
As shown previously flow towara the eastern side of the
landfill is evident from the nign specific conductances and specific
conductances increases in the stream This is especially evident
during low flow conditions when the stream starts at a point to the
east of the landfill and flows with high specific conductance levels
From the literature a relationship between specific conductance
and dissolved solids exists the dissolved solids (mg1) are
approximately equal to the specific conductance times a factor
ranging between 55 and 09 (39) in this case it is taken as
065 (41) The dissolved solids increase coupled with the stream
flow increases provides a basis of calculating the dissolved solids
outflow to tne stream This calculation method was used in a
previous study (26)
67
The relationship
=Cinout Coutflow Qoutflow - Cupstream Qupstream Qinput
where the numerator is the streamflow pickup and the C- and
Q-jnput is the concentration and flow input from the ground-water
This can be used to estimate dilution level outflows from the
landfill Initially this is used for the ambient ground-water
pickup between the E weir and the SE weir This entire flow doesnt
come from tne lanafill but much of it is conaucted in the high
transmissivity area between the lanafill and stream from upstream
leaxage ana surficial recharge Tnis is evident when this section
of the flow pattern is analyzed on Fig 22 Therefore the landfill
outflow is mixed with tne ambient groundwater flow which dilutes the
landfill leachate before it enters the stream To illustrate-this
concept a calculation using the 9 December 1981 monitoring is used
At this time a flow of 672 gpm occurred at the SE weir with a
specific conductance increase of 7 ymhos between the E and SE
weirs The dissolved solids increase would be approximately 795
Today in tne stream
Where
Co = 90 jumho at SE weir
Qo = 672 gpm at SE weir
Cus = 83 jumho at E weir
Qus = 606 gpm at E weir
Qinput = 66 gpm gain
Cinput = 154 jumho
68
The 154 jumho value represents the contaminant level in the
ground-water adjacent to the landfill
This relationship is applied to approximate the concentration
level dilution in the ambient ground-water between the landfill and
stream The aforementioned relationsnip is in turn applied to the
landfill outflow into the ambient ground-water flow adjacent to the
landfill The ground-water receives landfill leachate dilutes it
and then transmits it to the stream The previously calculated
value of 129 gpm was used as the outflow from the landfill
Co 154 jumho flows into stream
Qo = 67 gpm flow into stream
Cus = 83 jumho background level
Qus = 67 gpm - 129 gpm = 541 gpm
Qinput = 129 gpm from landfill
Cinput = 451 jumhos
Approximately tne same contaminant levels from the landfill (tbl
umho) are arrived at as existed in the summer streamflow conditions
when the upgradient ground-water flow adjacent to the landfill was
at a minimum
In addition to using specific conductance to define
contamination zones electrical resistivity can be used to indicate
contaminated areas The measured earth resistivity is inversely
proportional to the conductivity of ground-water Water containing
contaminants with high ionic concentrations are more electrically
conductive and will have lower resistivity values than surrounding
natural ground water Therefore resistivity methods can be used to
69
delineate plumes of contaminated ground-water that have hign
specific conductances This has been demonstrated by several
investigations (11122328374045)
In this study a Schlumberger vertical electrical sounding R-l
was made in an area of known contamination at the W well (Fig 12)
Given the geologic constraints provided by the well boring log a 4
layer computer model was used to match field survey values A
Schlumberger sounding R-2 in an uncontaminated area north of the
landfill in the same geologic setting was used to provide a
comparison background sounding (Fig 12) A seismic survey N-4 was
made to obtain water table depth and depth to bedrock as input
parameters to a four layer resistivity model (Fig 8) Tne results
of the electrical soundings have been tabulated in Table 6 and
plotted in Fig 27 and 28 respectively
The ascending portion of the field Schlumberger curves were
initially matched using a two-layer ascending type master curve to
provide an approximate depth and apparent resistivity of the
overburdened topsoil layer (8) Tne second unsaturated layers
apparent resistivity was determined by using the graphical
interpretation of total transverse resistance The total transverse
resistance is approximately eoual to the peak value of the curve
times the corresponding Ab2 distance it occurred at This in turn
is eaual to the sum of the first two layers apparent resistivity
times their corresponding layer depths
70
bullH
OJ bull bullH 4J CO CM
c ce G bullrH
j-gt ca c c a 3 ltu O L
co CO 0
bullo Q bull laquos c n 3 -U OrH f~ 3 bO ltn y CO O cc CO ^mdashN
QQ bull
bO bOJJ C C Ci_i
O l T i O O O O O O O O O O O O O O O O bullH bullH mdash^ bullo 0 C c3 f| 3 O raquo O CO CQ
CO
rH
CO O
L 4J
^ltU
i- 1 ^n ^b O 4-) bull2 CM bullH C OJ 1 -U bullH CO C L O a ^-^ 0) a
rH c a L CD ltu (1) 3 tlt bO cO I
3 a 0) a Q 4J laquoa e CO 3 (H bO c C O bullH
CO TJ C 3 bull
bull O bO -i-3
0 CO C O3- O G O O O O O O O O O O O O O O O O O O ft rt1 -raquo - t l S^ ft tfigt f I mdash^ K_ l_ raquo mdash I gt fgt I l 1
(1) 0 rH CO CJ JD o^^ CO CO CQH lts
71
Legend
A actual field measurement
-e- interpretat ion
10000 bull
6000 bull 5000
4000-
3000shy
pound2000| ltD
_ r 1000
09
5 600 pound 500 - 400
I 300 a a lt 200
100 10
Fig 27
20 30 4050 100
Distance AB2
Schlumberger Sounding
200
feet
R-1
400 600
72
loooot
6000 5000 4000
3000+
laquo2000 e
r 1000
raquo 600 pound 600 ~ 400
$ 300 a a lt 200
100
Legend
A actual field measurement
-Qmdashinterpretation
10 20 30 40 50 100 200 400 600 Distance AB2 feet
Fig 28 Schlumberger Sounding R-2
73
Formula T = f
Background Sounding (9000)(15) = (3110j (1 7) + gt2(8)
= 16214 n- ft
W Wel l Sounding (b200)(60) = (500) (2) + pound2(28)
= 13250 SL- ft
To determine a resistivityp3 value for the third layer a
graphical interpretation for the longitudinal conductance S was
used(48) This is eaual to the sum of each individual layers depth
divided by their apparent resistivity
Formula S = -r1 +~r-raquobull-ra
Background Sounding 0017 = yyg + ~^
= IbOU - ft
W Well Sounding 0285 raquo -ggg 7^3 J~
= 179 v-ft
These values were input to a program which calculates a
schlumberger sounding curve (47) The theoretical sounding curves
approximately match the field curve as viewed on fig 27 and fig
28 To provide a check on the apparent resistivity of the saturated
layer at the W well the following relationship was applied 1OOOO
= spec-jfic conductance (umhos)
74
At the W well the specific conductance was measured to be 3 00
jmhos at approximately 10degC
Assuming a formation factor of 45 for the glacial outwash (23)
material Archies law is applied to estimate an apparent resistivity
of the third layer (7)
fgt FF x p
A= 45 x 103-n-ft
A= 4G3 JL-ft
This is a reasonable approximation to tne 3i= 179^-ft calculated
analytically from the sounding curve interpretation
75
Remedial Measures
With the analysis of f low patterns and contamination zones
recommendations to minimize the environmental impact of the leachate
can be reviewed The basic technique is to minimize all sources of
water reaching the refuse so that leacnate production is minimized
The oiversion of precipitation by a relatively impermeable cover and
proper channeling of runoff would minimize percolation into landfill
material Caps and seals can be constructed of clays fly ash
soils soil-cement lime stabilized soil memorane liners
bituminous concrete and asphalttar materials (15) Proper
contouring and grading will help minimize infiltration If a soil
cover is used a vegetative cover can be planted which will utilize
some of the infiltrating flow through evapotranspiration losses
during the growing season By minimizing the length of slopes and
providing proper drainage channels tne surface runoff can be
conveyed to a downgradient area outside the recharge zone
Therefore this surface water will not increase leachate production
from the landfill Also by increasing the slope of the cover over
the landfill itself a higher percentage of runoff and lower
infiltration will occur
To minimize upgradient ground-water influx to the landfill an
impermeable subsurface barrier or intercepting trench could be
used Barriers can be made of bentonite slurry-trench cutoff walls
grout curtains or sheet piling cutoff wal ls extending to the bedrocic
or an impervious layer to effectively prevent water passage or
create a head loss that wil l lower the water table In addition an
76
intercepting trench which has a perforated drain at tne lowest part
of the water seepage zone could be used to intercept and divert the
entire flow
These possibilities have been evaluated with the help of the
model to determine workable solutions for this landfill The
primary concern is to eliminate leachate flows to domestic wells
Initially a simulation was run that eliminated recharge over tne
landfill area (Fig 29) This had a considerable effect on the
ground-water flow patterns of the landfill area The mounding that
had previously occurred under normal recharge conditions was
eliminated and a general drop in the water taole within the landfill
of 2-3 ft occurred The effect of eliminating recnarge over the
landfill when the upper stream is running would cause greater
infiltration from the stream as evidenced by only a 2 ft head loss
in the landfills flow conditions This is evident when comparing
Fig 29 with Fig 24 Tnis indicates that this measure would only
marginally reduce the resultant leachate flow from the landfill
material that lies below the water table In another situation
where there is not such a strong potential for upgradient flow this
measure has proven quite effective (6) In this case the landfill
cover consisted of four layers an intermediate sand and gravel
cover immediately above tne regraded waste materials a 4 inch sana
bed designed to protect the overlying membrane a ilO mil flexible
PVC membrane and an 18 inch final cover of sand and gravel
77
Legend
landfill limit -raquo- -^ -raquobull excava t ion x-^x- s t ream
400 copy WNWNEECSESC monitoring well locations
= -= unimproved road fee t
Fig 29 No Recharge over Landfill
78
Controls such as 10-30 mil polyvinyl chloride covers favor the
development of an anaerobic environment which increases waste
decomposition time and would necessitate installation of gas vents
at several locations on the landfill cover Tne integrity of tne
synthetic cap may be further threatened by subsidence which create
differential stresses on liners Settlement would create areas for
ponding and depression storage and eventually necessitate regrading
the landfill surface The landfills south-central area has oeen
filled within the last year and will prooably need to be regraded
due to settlement within the next few years
Another possibility for a liner would be a soil-bentonite
cover A layered cover consisting of natural materials with low
permeabilities such as bentonite clay followed by a layer of highly
permeable material such as sand and finally a layer of topsoil can
be used Due to potential drying out and cracking of the clay liner
a synthetic liner is the preferred method
The most immediate technique is to grade contour and vegetate
the landfill cover which has been done at this site Althougn an
impermeable cover would probaoly reduce the amount of leachate
produced it would not eliminate the upgradient flow and provide
guaranteed protection of wells in the vicinity of the landfills
northwestern section
A slurry trench along the northwestern perimeter of the landfill
would effectively cutoff upgradient infiltration and divert recharge
infiltration in a southeasterly direction thus removing possible
leachate outflows from the radius of influence of the neighooring
79
wells This has been simulated using the computer moael ana flow
patterns as shown in Fig 30 Contour lines are distorted in the
vicinity of the slurry trench due to the 200 ft nodal spacing
Transmissivity values of 1 ftday were input at the slurry
locations to simulate an impermeable barrier Tne surface recharge
at those nodes does not infiltrate the relatively impermeable grid
nodes at the slurry locations and flows to the edge of the noae
thus creating a dramatic head loss within a short spacing To
effectively simulate this a variable grid spacing should be used
with reduced node grid spacing at trench locations to eliminate
distortion The computer simulation shows that the slurry trench
could direct flow in the landfill area in a southeasterly direction
and away from endangered wells In addition it would reduce
upgradient infiltration from the stream into the landfill This
measure would prevent leachate from spreading beyond this carrier to
possibly contaminate neighboring wells
The combination of both the slurry wall and impermeable cover
would be ideal measures to minimize generation of leachate and to
stop its spread to neighboring wells The slurry wall without
recharge over it or the landfill is simulated in Fig 31 This
indicates a lower water table tnan eliminating the recharge to the
landfill The slurry wall has blocked upgradient ground-water flow
at its location to the landfill
80
Legend
landfill limit -laquo- j -laquobull excava t ion ^^- stream
copy WNWNEECSESC monitoring well locations
= = = unimproved road ssi slurry wall
f e e t
Fig 30 Slurry Wall
81
Legend
landfill limit j- j- J- excavat ion x-v^gt- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road s==s slurry wall
400
feet
Fig 31 Slurry Wall without Recharge Over It or Landfill
82
An intercepting drainage trench is considered next If a trench
was excavated to a 30 ft depth in the outwash material extensive
shoring would be required In addition difficulties would arise
when the trench was excavated below the waterline Tne trench would
be sloped to provide drainage and backfilled with a highly pervious
material to intercept and divert leacnate locally a conouit which
is perforated on the top to allow infiltration and unperforated on
its lower perimeter to permit continuous drainage to the collection
treatment center would be installed on the bottom of the graded
trench The difficulties involved in excavating below the water
table ano shoring the sidewalls to permit implacement of a drainage
conduit at a 30 foot depth make this option increasingly infeasible
83
Conclusions and Recommendations
The location of the South Kingstown landfill in permeable sand
and gravel glacial outwash material (107 ftday) combined with the
high hydraulic gradient across the landfill area (20 ft1600 ft)
creates a high potential for ground-water contamination to occur
This is intensified because refuse nas been placed below the water
table The low hydraulic conductivity of the compacted refuse (1
ftday) and the excavated area to the west of Rose Hill Road have
both contributed to modifying the original southeasterly flow
pattern These modifications have created a ground-water divide in
the landfill at approximately the western third section Tnis
results in approximately 13 of the leachate flow from the landfill
or 63 gpm flowing in a southwesterly direction and 23 or 129
gpm flows in a southeasterly direction Infiltration from
precipitation recnarge over the landfill (up to 9Upound) and from tne
upgradient stream during low water-table periods provides tne
necessary influx into the landfill Evidence of contamination is
clearly seen on both the east and west sides of the landfill which
reinforces the previously stated flow patterns
Of the several remedial measures reviewed the contouring and
grading of the landfill topcover and drainage swale provides the
most immediate protection The topcover has been graded mulched
and seeded to provide a low runoff slope generally to the east
The drainage swale on the left side of the landfill has improperly
graded sections which should be corrected Its northern section
could be drained into the northern sections swale and the southern
84
section drained to the southeastern section of the landfill Tne
point of the drainage swale which divides the northern drainage
swale from the southern one should be determined by a field survey
Cost is a major contributing factor when determining which
remedial measure is to be applied to the given situation For the
purpose of this report cost estimates are not presented but rather
the effectiveness and feasibility of the remedial measures are tne
primary considerations As was reviewed and simulated in the
computer models the slurry trench and impermeable cover over the
landfill are two viable options that would effectively provide
protection to the domestic supply wells in tne vicinity The
impermeable cover would eliminate precipitation recharge into tne
landfill yet drop the water table only a few feet due to upgradient
infiltration from the stream This would decrease the hydraulic
gradient thus diminishing the potential for a contaminant outflow to
surrounding wells The supply well of primary concern is one to the
west of Rose Hi l l Road marked well D on Fig 2 If contamination
occurs in this well the most effective measure would be to block
off leachate flow in this direction by installing a bentonite slurry
trench at the location indicated previously This would effectively
prevent leachate flow in the westerly direction and diverts it to a
more southeasterly direction In addition the slurry trench
precludes infiltration flow into the landfill from the upgradient
stream
85
Tnis report has effectively reviewed tne original ana existing
flow conditions and contaminant levels in the vicinity of the Rose
Hill landfill The purpose was to provide an understanding of
ground-water contamination patterns and study possiole remedial
measures
86lt
Appendix A
Precipitation Records
Monthly normal precipitation 1941 -197O
i$l Total monthly precipitation
KINGSTON RI
14
ia
^JO T I bullbullL
pound 111 laquobull
4
a
n
-
^
-
-
KS1JAN
^Ii R3 HB MAR
1
1 APR MAY
1
1 JUN
1981
JUL
-bullraquolaquo H
AUO SEP
K3~~f$s bull
_imdash
i1S 1
OCf NOV OtC
171 1 iI1
JAN HB MAR APR MAY
198
Fig 32 Precipitation Record
- - - -
IM 1 MtvJrflgtlgt c ortli-A t lUN I r nraquo rl - -
gt|MO CLIMATOLOQICAL OUSERV ATIONshyr-r bull JK gt raquo - 1
i5fWA I VAPOR Al IOH -bull AIM If MPCRATUM bullF 0 riccipn AT ION UNO IlMf
bull 14 H 14 H mdash Vshy ADDITIONAL DATA IfUAlUS OATt 1 bull raquof bull bull 1 ta
14 Hw rlaquo4 w bullbull bull 1 114 1mdash4 (llrl 1 1 1fl Hll
0 kmdash
Mraquo M4 raquo i T i 4 bullraquo-laquobull i i
Lgt f 1 21 S 1 Hbull - - bullbull -
ltJL 1 2 01 - - _ _ 1
mdash
-
1 12 _ Q I
mdash shy
mdash 4 (C ( - - fVi 1 - 0
1 (1
^ 1
Vvraquolaquo IJ1^ raquo CP O 3L 1 Z - i bull j-t-J
1 J
LH Vb T n 0
1 gt fl oo O ~l 2 L - bull 1 P )laquo jn iP IP - OOI L5L mdash shy
-t 84 ^(^^ ^fi P i flja 0 JO II 10 tl tcgt 7 J IV wllaquo
h l2L bull 0 lt -_ shy
-id VJ lt 3C 2 ft OOL -mdash
U 71 C1 Sr 2 13 2 nl JLJraquopound HP r M ltf1- (
IMe 2 ii O It
n jlt dl 1 1 bull o o-il ST i 1 i 25 2-x-1
-
ri
i tlL O mdash gtbull bullgtlt 1ft -o- is Oil So iJK 2-io otv u 31 fil loi 2 il Oll it Of wr is i1raquo -iZ 1 deg|0 01
M IT So - mdash
- 13 1 CT mdash i - mdash 21
shy
Tl Ci av ZUll IMT 0 IM Pe v _ 1) T) S) ii3( dlt Ii 2 lt^2 II li- S1 riivi To 7HX lt3lO 14 ^2- iTi I li 011 -- - -i -^IS no 5^ or i | T Jift laquoV OoH bullla It Va iCO mdash L OIL 11 bullvf poundgtpound lS_ flv oh P-lfe 1 poif _ shy11 IB kl (4 itlaquoT lamp llt0 oot^
mdash -n
It T1 |ir( L1 HI 2 0 oil
U 1M ft go C ICf^ -^2 Z laquo-|o
11 it 5 bulln - TO o abull Li u-i IT1 -- Iw O ltM (I bullbull bdquo-I(K 1mdash -tilltLlA ttfe
i Dgt ac -- U 44 4 11 1 1- ytd i i_i J-K 0 i if -i i i V t Wl raquoOHM 1-1 US D C P A R T M f N T OF COMMfRCE t 4 1 IUII 1 1 ^~) mdash
llaquo- Hi NC bull bullh bull bullJL^V HBl CO 00
11
)jLsVyr^gturv
^ | TKu
|-_t_ bull(
IIMgt I I Mt|UU III- II 11
PNECIPITATIOH
I 1 1 IMX
IMO
bull llfclaquo I UCIUKI) Ur C V A r U M A AHO CLIMATOUOCICAL OBitH
E V A F O R A T I C r i Jttffl laquo amp hMIlaquoJllaquoJIIlaquoBgt
DATE AOOITIOMAL DAIAKMAKk M
bullraquobullmdashlaquo
tp 01 (1 Of Ll OOI ooo
0^1 o-i 10 tl |00 102
OC (1 13 Ofl
it i rc DS os an
(1 SV o
Ul 010
(ISl 101 I on
130
II 5= Otl
ss lt 001 (IK Ml
jt il HIT
7 it
ow Wo 17 Top 2-01 OIO
(0 oov zi oot
u CO ^A 0 to Zoi CLflS
bull50 01 ljtj
nshy 5H LO OIt
50121 IVO QJO
14 Co Ho LO Hl ^pound Jl 1
ltM ool fllc
H Tl 01 II
11 11 Q1
iH OIO
HO 2 llaquol 11 II
lifc
IV-IIM ul OIPAITHINT or COHMIICC NOAA
NAtlOHAL gtIATnlaquoll raquotraquoVlClaquo CD
r~
All TCUMMATUNI ^V UII rgt ITmi 1 Cwphu Obic i gtn t ngir-H 30
rilCiriTATIOH
JJ T I rTJ-rimdashr-iramj|MP CLmATOLOQ
laquolaquo jftilCiii bullIHO
Oi1l ADOITIOHAL DAIAlllu
Ilf4ft
Sii1
(1 2 IO OO
Hl ii SO
us OIM
Q^L
a A3 Hi SZ Sf^ bull 12J2
HI Z-SF OOl 1C t HM IA H ICP fiJA
OOl 10 (310 sn 310
if HI (0 ^01
bullit SO 28H poundJ1 11 006
14 35 TX oon II (bull2 it zr II c-S
rr Zll lo 31 OP an 31 a 31 oor
CSW O-ll Si CC Of 011
Oll _ I |ft
00
u i oerraquolaquoTMiMr of c NOAA
NATIONAL K C A T N C M SCMVlCC
TC^S lk)oiVroTJA
TETT I 7X
1raquolaquolaquo 4 bdquo ir lt er ni I^OV ltqgl j--^ TQ
MICiriTAllOH ITIND
D|mdash
b5NO ctiUATOtoiCAL oeit^
OATI AOOITIOMAL OATAVlHAtt
0-tt
Mlaquoh bullbullbull- rshy laquo
I- ltltriu HI I 4 bulllaquobullbull1
Zii
30 Dfellt otvt
at HA
OOI
62
iJ_S2 HI if
bull- 20 SI 2i So
So
VVfr
OSfc
I (
Jtlt
3aoi
r j -bull ie MA
Irill iiol
in^ 14
Mo
Zll
214
21 1P
00-i
bulliron
17
bullr
11 i ir- I J Ktf^c
US D E P A R T M E N T OF COuMEDCC I | C gt A A
K AIlaquo Ttupf lATuit r
|SlVi AlJ PIICIPITATION
oJud (El
VIM i Uraquo
MIND E
EVAPORATIOH flnrft bull A ftufiifccdll
KECORO OF eVAPllHAtlil bull I CLIHATOLOOCAL OBSERVA ^Hij
14 MM A_M AOOIIIONAL DATA11 MAIM
Mr bullH Oo|
M Si lift
bull221 IHI
ZS Ji 40 IZV
icr KS I
HZ 111
bullT 21
loA UK JA IP
v^ ft
1M 2Sshy IT Tl
71 V |
i I 31 1deg a
uty^ U bull3
ons 1 CiO TxX
HHO (10
3H 19 12 10 IP
raquo3H raquo | 5t io
OP OIT
14
vO UI Of PANTMINI Or COMMCRCf MM O A A
F ngt TIHH
iiicffwiffc 4 rJ (TIM bull Cempltit Obitittiio
AIlaquo TIMHIATUM PHICinTATION I V A f OK ATlPrl
OATI ADDITIONAL DATA KMAlIt
U4laquo4 +
03H Ji
10
rc a 1 16 oi ii
tiiy 10
OI
II i23 or o 13 -y~ou HO
II 3V III i 3 t
V laquop oot
OM1 SS ne
T an -i IP
Olt zr LTV
3T 001
a -11 2T
10 an 31
-1 raquo 131 UP 3H lf 14 Lpoundshy
it 14 30
IS
Ui O I P A K T M f H T OP COWlf ICfM O A A
NATJONAI V C A T M C n f t K M V l C K
bullbullbullbullbullshy -2 o AIlaquo TIMMRATUM f fKICIPITATIOH
OATI poundt- MMINMAL DATAk
ZP 51 lo icr
011 111
OoT IHf
Ut 003 am
3o 13 ao
4A X 05shy
H4 i IjJyiV131 ooc js
IH oi 01 tL 18 13 a
No 11-7
rivgtp OO| M Hi 03 01
It 12
bull I 41 bull7119 14 ^^ raquo 31 15 lampk n M ho i
Jo -j-
-J
I
Ml H^ I _
amp2ampUi^= LS 0 S 0-f bullTTT
-Vmdash gt U_ bull 1 rOHM I- 11 OI OCPARTMlNT OF COMM(NCC
HO NATIONAL W f A T M f H ftfraquoVlCI
98
Appendix B
Boring Logs
99
X iHECT 1 ff 2
OAT American Drilling amp Bor ini I Co Inc
wo WATH smn EAST PR ov IDENC E ft 1 Town of South Kingstown South K ngstown R I MOLENO X-J
TC 100 RCSS bull ujrMonitorinq Well Installation | South Kinqjtown R I UNC a STA Pf KXICCTHJ LOC ATK3N
bull cfrserrr TO above S MPLES S FNTTO _ _ |laquolaquor A-109 SURF ELEV RE PORTSEr
GROUND WATER O6SE RVATC MS 1 CDREraquolaquo m-T nn75 laquo A 256 - 20 mdash Hew y
Instolled 32ofT-l2 PV C - JO- COMPUTE 111275 K toia 3- I-WI 1-38 TOTAL MRS bdquo10 screen BORING FCACUAM J K lanq MAI rraquo HomnwWI 300 140 IampPCCrc Mamlaquor Fall 24 30 lampaaiona SOLS ENGR
LOCATION OF BORING H ONITOKING WELL
Coung Samplt Tjp Blow per 6 Manure SOU IDENTIFICATION Strata SAMPLE ^^^yV Bloot
foot
Otptni
From- To
el
l
on Sampler
0-6 1 -6-13 12-18
Dentity or
Conmt j
Chang Remark include colo^ graaation Type of tod lie Rao-coMr type condition nordshynetiDntotf time leamt and tie No Pen Rtlt
2 No top sample 5 12
1 loamy fine sand
bull)^ 40 30 36
5- 616 0 23 20 16
noist iense
Brown fine to coarse SAND some fine to coarse gravel Trace silt
^
1 18 18
36 8-0shy57 40 30 V 35
|0-||-6 D 14 24 20 Srown medium to coarse SAND Some fine gravel cobbles
7 IRshy 16
27 75 37 3
IS- I- D 5 14 16 3bull
ISshy 15
42 50 I9--0shy50 65 20-2ll-6 D 9 23 26 bull Jrown fine to coarse SAND Tbullwshy 1Z 75 90
22-0 Trace silt trace fine gravel
124 120 74 60 52 41
7S-ltlaquoil-A DX 71 16 13 wet very dense
Gray-brown fine to coarse SANC Some fine to coarse gravel little silt
H IR u
40 30--0
3C-30-IO
3l4-334
334-3314
38 4-434
D
c
C
C
7 IflO
94 6
we tr j
y se
ft irox
30MOshy
31 -4shy
Gray-brown fine to coarse SAND Trace silt
Gray-brown fine SAND some lilt trace fine gravel
Too of Rock 31 -4shy
Gray-pink GRANITE
6 7
amp
CJ
IltJ A
60
601
IQ mdash
2(
4
5 i Hard
ft 5ome seams bull
GROUND SURFACE TO J 4 U3CD_ ^JVrf bullbull( tutu t to 4o 4 SampM Type Proportion UMd MOB Wtx 3 OfaM on 2OD Sampler SUMMARY-
OOry CCartd WltWen4 Hoc OlolO Canmonieraquoi Don any CoKeem CarMWncy Earm Barrlaquoj 11 14
UPgtUnOigtturod Piuon trite (Oto20dego 0-Kgt Loei it 0-4 Sait 3O+Hofd Rock Corng 14 Kgt-30 laquo4 0 rte 4-8 MSHM Samplet TPTtitPit Ai Auger Vvanefett tarn 2Olo39 3O-M Owlt n laquo-lS Strlf rinit nn v 1
UTiUndlshffbed ThrMOll and bull 33to9O 5O Very 0laquo nraquoe 19-30 V-3trraquof - | OLE NO X-l
TOVH rim - iA it raquotoraquo
100
SHEET 2 o_L
WO WATEt STUET [AST ft OVIDENC pound a i American Drilling amp Bor ing Co Inc
MCLl WQ X- 1 Tt AOORCSS i
LIME A STA KXICCTMJ tuf same as 1 | tame as i LOCATION
W PORTSEf mo OB nj urt eflaquo T
illtPLES S
P
CVTTO nlaquo mun orv
^s f^ Tin i GRCVMO WATER OBSERVATONS CASING SAMPLER CORE BAR
START Typi COMPUTE tome at 1 same aiH
TOTAL MRS BORIMG FOR CMAN n bull IT INSPECTOR SOILS EMM
LOCATION OF BORING u HfVJTneTfi UFI _
8
Counf Blo-t
foot
Dtpllo
From To
0( on SampMr
0-6 f 6-IZ
Moittir
Oonuty or
Contilt
Strata Ctnngc
SOIL OCNTiriCATION Rtmorkt ineHifl cotot grqdotion Typlaquo of Mil etc Roo-axtrPlaquo condition Mrdshynlaquot Drog tun ttomt end tic
SAMPLE
No Ptfl RfK
434-4o4 c
approx 7 minj
per toot 454
Gray pink GRANITE Hard Fairly solid core
lt_4 24
Bottom of Boring 45 -4
-
~
bull 1
GROUND Sorrow Tye
SURHCZ 10
bull OiOry CgtCord WWothod UPUnditiurMd Piston TPlaquoTtraquotPtt AtAuotr VVor
UTltUndinrvd TTMMO bull bulltat
iivnPilaquo(onioni Uraquot4
me OioiOItttt laquoraquo20
wmt Z0ie33
and 361090
c M
C1 5 Si
-SOshy
ASING
IOtgtWtigt bullnlot Dn 10 Loci M Mod 04 SO Dm 1shy Viry 0laquo
s _
TMEN 0 hMl on 200 SoiTBUr laquoity ConcMMt Conorawncy gtbull 0-4 Sort 30shym 4-B MStlfl M BH9 Strtf bull ts-so v-swt bull
t-HOrt Ear Bern RoetCorrt
i ^^^^^ bull
-[MOLE no x-i
101
raquoMEC rAmerican Drilling amp Bor in g Co Inc 1 ofj_ DATE wo WATlaquo smn UST Plaquo IOIDCNC j laquo i
Town of South Kingstown South Kingstown 8 MOLE MO Jlt Z TC rx MCS3
rtprr uAurMonitorina Well Initollation | South KinqitowrxRI UNC A STA P KATIOM ME POCT ^rwT TO above I OFFSZT
uD^r laquorlaquorTTO 6 -109 suw tLEv Sgt louffJOCNO
0 tj Tlmlaquo WOUND WATER 06SCRVATC US gtW Rsdl SING SAM^EH CORE BAH
26 ^_ 12 $TAlaquoT UL 2Z2i Ji r TTP NW ltA sr IJZC Z5 CCOMPLETE
SitLO 3 I-3B- 1-38 TOTAL MAS 41 BOAINO FOACMAN JK1 ana nf ni n MonwwWl 300^ 140 BIT bullK^CT
gttonvrar Foil J^laquo 30mdash Diamond SOOJIEMGM
IE HFII
iCaunq SampM Trplaquo BMMtpw6 UOIIIK- SOIL DCMTIFKATION Siraia SAUPLE Blow DlaquoPIAraquo of on SompMr HtmorU mcJuo cotes gradation Type of Dwuily
pw or CXang writK Roel-eolorlyp condition tvort-From- To Vfoot 0-6 f 6-2 12-18 Coniitt egt rwtiOnAngtimt wamaondtte No Praquon Rtlt
2 Brown fine SAND little silt 2 2-0shy5 15 18 moist Browi fin to coarse SAND 18 5- 6-6 0 14 25 27 vlaquo Troc fin aravel | 25 wy Ifl 11
dlt tns 35 40 38 moist n in-il-i Lgt U 15 18 ie is li1 Irl IS 31 I2-0
~~43 1
A) Jrown coars to medium SAI MD 48 moist Little fine to coarse gravel
|5-IA-Xlaquo 14 47 41 fn D laquo y Little silt rrqa coarse sane 3 18 I1
68 In IS 44 32 34
n ^n-^i-A- w 2o 19 29 wet 4 la -59 lens ltfO no
25-0 2amp bulllaquo- 77 c BOULDER r[ 4 i
27-0 5X ~W 24 24 bullWar- 5 Ifl irown tine to coarse SAND some
dens 29-0- Fine-coars gravel trace silt
30-3I oxx 30 32 30 moist irown -gray fine SANDiom e 6 l rr Vlaquoy 31 -0 silt trace fine oroveTILL
Bottom of Boring 31 -ampbull shyBent casing -pulled out and moved over 4 - washed amp tJrovlaquo casing to 30 -Installed 3C gtof 1-12- PVC - 10 screen
WOUND SUraquoraquofCE TO 3pound 1 yijfD MW t ASIMC TMCJ laquo olaquorod -bor of borina
SomoU T]Fplaquo ProigtuliOraquoH UMd MIOtgtWLx3Orolt lon2OASanlaquoMr SUUMARY-D=Dry CCorad Wlaquoworaquonraquod bullact OiaiO CanM gnMM Daonty CIMIH Caamraquoci EffW 8or^ 2pt
UPiUnairurMd Pition Itnt laquoM2O O- O UKraquolaquo 0-4 Soft 3O-hHard Roelaquo Corrig o- JO M0mlaquo 4-8 MSNff SOTipM 1 p^ 3O-9O OwgtM bull-IS Slid
TPlaquoTraquojraquoPit AAugtr ViVon mini tamt 20to39 UTtundiifir6d TrwMOtf and JSloSO 50-raquobull Vary 0nlaquo [HOLE NO x-2 B-3O V-3Mf lev rim - IAIT raquosectlaquoraquo
102
300 iu 24
1 UMnii ffi 140 laquo 30
CA1INC tf
gt taWCTf
bull 0gtlaquo i R Cook Jr_ R Millineton1 Wttn
I~
1 VAMtl CtMG
1 W HO-t MO
1 Oraquo 1 laquo0~ twt
L 1 laquo-raquo VfcM^lf [wlaquoraquoCI ^ ^ K3Ot III laquo
0-LS D
5-65 D
LlQ 10-115 D
15-16 Tgt
Lraquo 70-51 n
25-26 D
F
I O-O Ci
A Allstate Drill ins Co vi o i
PROVIDING R 1bull raquoraquo uvraquonn~ N M O M I T O P I N G HE1 _^lt -^ PI-Traquo UJU
CUM Town of South Kineraquotown raquoraquo 1 1TA maoer Propolaquolaquod Sit for Slude Disposal nltn
laquo V-449 iampAAtut i a 138 ort STI bull r 42777 CtOuMO IKVtllON
Cill bdquo 258 DA II MN ru 42777 rilaquolaquodO laquoraquoTti rum 1911
AU1TATI
MMUI1 raquolaquogtlaquolaquo laquoKiO itXHHKraquoriOi of sous MUAHI nMTKlion Ot CMlaquoMC|kOraquort tl CO~VH DXltgt raquomlaquo laquotf IMi COIOI C4l II I 1raquo gtlaquo^ Oraquo 1Ol rC t Xgttgt VtfKOe Craquo Mi 1 ft liMraquoK laquo0^tlaquot nfgt
1-2-1 10 TOP SOIL FINE LIGHT BROWN SAND traclaquo of ilt
16-31-17
22-24-21 100 FINE TO MEDIUM LIGHT GRAY SAND trace of fine gravlaquol and raquopoundLt
lfl-37-34 150 LIGHT BROWN FINE TO MEDIUM SAND little poundinlaquo gravel
21-17-15 200 MEDIUM TO COARSE SAND bullomc fine gravel
12-4-10
265
Observation well installed
NOTE No casing blows taktn
bullbull B-23 ow
^w^ 265 I raquo bull raquolaquo bull I W
11 laquot gtbullraquo Vlaquo 14 W gt_ c-shyji bull alaquo bull jraquo VI laquoHshyw bullbull m raquobullbull D-6 raquo Mshy
bull bull laquo Vshy
1
bull bull
I
103
MAMMII Allstate Drilling Co ulaquorr 1 or 1 FftOVIOCKZ H L traquolS mTArm^S MONITOR NR WEL
VNO wr3JJO__raquoraquou_24__ HCU MO P-74 n iu riBwi Town of Slt7H^ Xirpin
mdash^ laquo0J P 1 1 bull ^n^ciit^o TVlaquow^laquott1 bullraquoit wt 140 nu 30 olaquor fBu lkv Waste Disposal Arcai
MUTAH a V-449 R Cook Jr UMlaquoiigti D 1 38 0t| raquoIJ raquo 5277 rlaquo SUMO luvlaquorv-laquow
mdash 5277 fipe -raquoT pfpm 150
H MCIO IMNTlXAflON Of SOU t(kAIlaquoS rrn 0-laquoraquo
5 -SF 01 w in laquobull -raquo ^ lit
D 1-2-2 TOP SOIL V-1-oraquo
15 IPbull FINE TO MEDIUM LIGHT GRAY SAND AND GRAVEL
5-65 D 37-27-35 some silt
10-11 D 20-14-18
15-165 D i 17-14-14 155
BROWN COARSE TO MEDIUM SAND little fine to coarse gravel trace of silt
20-211 D 4-4-2
230 GRAY BROWN VERY FINE SAND
25-26J D 7-8-9 AND SILT 265 fvarvedl
Observation well installed
NOTE No casing blows taken
wta 10 n uuraquo c^imdashbull IgtM laquolaquobull- B-24 ow ~ 14 ltfc laquoraquobull vlaquo^ M laquobull r O 0 fmtt bull W-L 26 5
-0- CgtCmdashgt bull laquolaquobull mdash laquo 1 - raquoraquo 1 gt 1laquo bull 1 gtraquor to bull mdashbull bull bull bulllaquo I t l~laquo 1lt Uraquo mdashbull ) bull 1 gtbull ft 0~ H laquoy bullM ta bull -IN la laquobull OPUM bull($ IMI
mdash H raquo laquo-bull
104
Appendix C
Calibration of Specific Conductance Meters
105
Specific conductance measurements were made using a beckman RB
338 temperature compensating meter and a YSI rtooel 33 salinity
conductivity temperature meter The YSI meter is not
temperature correcting A formula to compensate for temperature
differences to standardize YSI measurements was used (21)
A long probe for the Beckman meter was used to measure conductivity
in the wells Differences in conductivity between the YSI ana
Beckman meters and the Beckman short and long probes exist These
were calibrated in the laboratory using 001 N and 01 N KC1
solutions Values presented are Beckman short probe values The
Beckman long probe values were reduced by 76 and tne YSI values
were multiplied by 11 to adjust to Beckman short probe values The
YSI meter was used in the latter phases of the study for the
stream contamination due to the greater accuracy of the dial readout
scale
Table 7 Specific Conductance Meter Calibration Table
Concentration (KCL) 0001N 001N
Specific Beckman short 145 143 143 1247 1245 12GO
Conductances Beckman long 190 191 188 1639 1650 1665
umhocm 9 25 C YSI 132 131 128 1131 1140 1150
average values Beckman shortBeckman long = 075
Beckman shortYSI = 11
106
Appendix D
Computer program Flow Chart
107
F1g 33 Computer Program Flow Chart-
1TpoundR MAP TCO
NEWPER
WEWSTP CZAX
HEWIT TRANS TCOF ROW COLUMN
Yes
Yes
108 The following is a description of the USGS two-dimensional computer
program Iterative Digital Model for Aquifer Evaluation updated
December 1972 by P C Trescott The program written in Fortran
consists of a MAIN program and six subprograms or subroutines which
themselves are organized into subprogram sections The subroutines and
their sections are listed below
MAIN Program
DATAIN (subroutine) COEF ITER (section) CLAY MAP TRANS NEWPER TCOF
ETRATE COMPUT STORAG
NEWSTP LEAKAG NEWIT1 NEWITO CHECK ROW CWRITE COLUMN STEADY PRNTA OUTPUT DRY BLOCK DATA
The program begins in the MAIN program which controls the sequence
of passage to the subroutines Sequential steps are described in the
program as shown in the flow chart of Fig 32 Emphasis is placed on the
steady state confined aquifer case as applied in this study First data
input is read in the DATAIN subroutine This data includes transmissivities
or permeabilities starting heads storage coefficients and grid spacings
Nodal transmissivity values are then computed for the water-table problem
in the TRANS section (COEF subroutine) This procedure is necessary here
because the subsequent routine for computing iteration parameters (ITER)
keys on nodal transmissivity values which would not have been input to
the water-table problem In the water-table option these would have been
109
computed from given bedrock and water-table elevations to obtain the
saturated thickness component of the transmissivity calculation In this
study water-table option was not used and the transmissivity values were
input directly The program then passes to the ITER section (DATAIN
subroutine) to compute the iteration parameters which expediate or even
cause convergence Next the MAP section (DATAIN subroutine) is utilized
to initialize data for an alphanumeric map if this was requested in the
input options Transmissivities are then computed for the confined
(artesian) aquifer case (water table not specified with input options)
in the TCOF section (COEF subroutine) These coefficients are harmonic
mean values of adjacent nodal transmissivities weighted by grid sizes
Time parameters and pumping data for a new pumping period are then read
in the NEWPER section (DATAIN subroutine) followed by entry into the
NEWSTP section (COMPUT subroutine) which calculates the size of the
time step Leakage coefficients (hydraulic conductivity of the confining
bed divided by confining bed thickness) are next computed in the CLAY
section (COEF subroutine) if leakage was specified in the input data
which was used in this study
A new iteration is then initiated in sections NEWITO (COMPUT
subroutine) NEWITO saves the current head values and compares them to
the updated head values for determining closure This is followed by
nodal transmissivity values being computed for the water table or water-
table artesian conversion problem Transmissivity coefficients are then
computed for the water-table problem in TCOF (COEF subroutine) Total
head values are then computed with the alternating direction implicit
procedure using the Thomas algorithim first along rows in the ROW section
110 and then along columns in the COLUMN section both in the COMPUT subroutine
Then if a solution is not obtained (because the error criteria for
closure is not satisfied) the MAIN program branches back to NEWIT1 subshy
sequent sections TRANS TCOF ROW and COLUMN repeatedly until a
solution at the particular time step is achieved NEWIT1 increments the
iteration counter and is immediately followed by NEWITO The program then
moves to the STEADY section of the COMPUT subroutine to check if the
closure criteria for steady state has been satisfied Output is then
printed in the OUTPUT section of COMPUT if steady state has been reached
or if the particular time step is designated for output
The program then branches back to NEWSTP (COMPUT subroutine) and
moves through the subsequent routines until the last time step in the
pumping period is reached Output is then promoted in the DRY section
of COMPUT if specified in input data If the last pumping period in
the problem has not been reached the program branches back to the
NEWPER section and moves again through subsequent sections otherwise
the program will terminate or start a new problem if one follows
This study was simulated as a steady state problem which can be
simulated by setting the storage coefficient of the aquifer and the
specific storage of the confining bed to zero and using one time step
of any length
111
Appendix E
Computer Data Sheets
RGSEA
10 ROSE HILL LANDFILL MODEL 20 30 40 LEAKAGE 50 60 70 CHECK 80 90 100 HEAD 110 120 1 23 IQ 100 5 001 37E-OU 0 130 100 001 0 0 1 4 0 - 1 - 1 1 - 1 - 1 i i i i i i 1
ISO 1 10 0 1547E-05 01 10 1 1 160 04642 200 200 1 1 i it
1QO 190
CARDS I THROUGH 19 - CODING SHEET
CHEAD
100 110 120 130 131 132 140 141 142 150 151 152 160 161 162 163 164 165 170 171 172 173 174 175 176 177 178 179 1BO 101 190 191 192
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 539
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 58
25
25
25
25
25
25 621
25
25
25
25
25 662
25 25
25
CARD SET 2 - STARTING HEAD MATRIX (FT)
193 194 IVb 196 197 190 200 201 202 210 211 212 220 221 222 223 bull 224 225 230 231 232 233 234 235 236 237 23B 239 240 241 250 251 252 253 254 255
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 23 25 25 25 25 25
25 25 - 25 25 25 25 25 25 25 25 25- 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 - 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25
25 25
25
25 25
25 25
25 25
25
25 25
25
25 25
25
25
25
25 25
25 25
25
25 25
25 25
25 25
25
25
25 25
25
25 25
CARD SET 2 - STARTING HEAD MATRIX (FT) - continued
STORC 1512 FRI 19 FEB 82
100 110 -1 -1 - 1 - 1 0 0 120 130 140 ISO 160 170 100 190 200 210 220 230 240 230 251 260 261 262 263 270 271
CARD SET 3 - STORAGE COEFFICENT
LEAK
100 110 120 02 130 _ 18 02
I ltu 18140 025 150 02015015015 19 deg25
02 160 022 bull-laquo- J1 5 j 1 z laquo- l^
170 015 180 016 laquo02
190 016 OE025
200 02504019022021025 2 5 i S lt03 0252i2 n
230 030 deg23 deg2 deg2 deg2 -02023023 240 022 250 022025025 02
027043 013025
30() 025025025 310 025031 320 024025
CARD SET 5 - AREA OF STEAMBEDAREA OF NODE
120
Appendix F
Bibliography
121 BIBLIOGRAPHY
1 Agpar MA and 0 Langmuir Ground-Water Pollution Potential of a Landfill Above tne Water Table Groundwater V 9 No 6 1971 pp 76-96
2 Allen William B Hahn GW and RA Brackley Availability of Ground Water Upper Pawcatuck River Basin Rhode Island USGS US Government Printing-office GS 66-624 19bb
3 Annual Book of ASTM Standards Part 31 Open Channel Flow Measurement of Water and Waste Water by Weirs D 2034-68 1975
4 Annual Book of ASTM Standards Part 19 Infiltration Rate of Soils in Field Using Double-Ring Infiltrameters D 3385-75 1975
5 Baeaecner MJ and W BacK Hyarogeological Processes and Chemical Reactions of a Landfill Ground Water V 17 no 5 1979 pp 429-437
6 Beck WW Dunn AL and Grover H Emrich Leachate Quality Improvements After Top Sealing1 8th SHwRD MERL Symposium 1982
7 Beckman WK Transient Modeling For Estimating Sustained Aauifer Yield master thesis presented to the University of Rhode Island Kingston RI 1978
8 Bhattacharya PK and HP Patra Direct Current Geoelectric Sounding Elsevier Publishing Co New York 1968 135 p
9 Bouwer H Ground Water Hydrology McGraw-Hill Book Co New Yoric 1978 p 378
10 Braids 0 Cocozza pound Fenn D Isbister J Rous P and B Yarc Procedures Manual for Ground Water Monitoring at Solid Waste Disposal Facilities Environmental Protection Agency530SW-611 Cincinnati Ohio 1977
11 Cartwright K and MR McComas Geophysical Surveys in the Vicinity of Sanitary Landfills in Northeastern Illinois Groundwater V 6 no 5 1968 pp 23-30
12 Cartwright K and Fd Sherman Jr Electrical Earth Resistivity Surveying in Landfill Investigations Reprinted from Proceedings of ohe lOtn Annual Engineering and Soils Engineering Symposium Moscow Idaho 1972
122 13 Clark TP Survey of Ground-Water Protection Methods for
Illinois Landfills Groundwater V 13 no 4 1975 pp 321-331
14 Dunne T and LB Leapold Water in Environmental Planning WH Freeman and Company San Francisco 1978
15 Faro DG Upgrading Hazardous Waste Disposal Sites Remedial Approaches US Environmental Protection Agency500SW-677 Cincinnati Onio 1978
16 Fenn DG Hanley KJ and TV Degeare Use of the Water Balance Method for Predicting Leachate Generation From Solia Waste Disposal Sites US Environmental Protection Agency530SW-lfa8 Cincinnati Ohio 1975
17 Geisser 0 An Electric Analog and Digital Computer Model of the Chipuxet Ground Water^ Aquifer Kingston Rhode Island master thesis presented to the University of Rhode Island Kingston RI 1975
18 Hahn GW Groundwater Map of the Narragansett Pier Quadrangle Rhode Island Rhode Island Water Resources Coordinating Board GWM 5 1959
19 Hemsley William T Koster C Wallace Remedial Technique of Controlling and Treating Low Volume Leachate Discharge USEPA National Conference on Management of Uncontrolled Hazardous Waste Sites Oct 1980
20 Hughes GM RA Landon and RN Farvolden Hydrogeology of Solid Waste Disposal Sites in Northeastern Illinois Final Report to US Environmental Protection Agency PUD SW-l^d Cincinnati Ohio 1971
21 Keller GV and FC Frischknecht Electrical Methods in Geophysical Prospecting Pergamon Press New YorK NY 19bb
22 Kelly WE West Kingston Landfill An Evaluation of Its Effect on Ground-Water Quality Rnoae Island Water Resources Board Water Information Series Report 1975
23 Kelly WE Geoelectric Sounding for Delineating Ground-Water Contamination Groundwater V 14 No 1 1976 pp fa-10
24 Kelly WE Ground-Water Pollution Near a Landfill ASCE Environmental Engineering Division Journal V 10 No EE6 Dec 19b pp nay-nyy
25 Kelly WE personal communication January 1982
123
26 Kelly WE and OW Urish A Study of the Effects of Salt Storage Practices on Surface ana Ground Water Quality in Rhode Island NTIS FHWA-RI-RD-8001 1981 54 p
27 Kimmel GE and OC Braids Leachate Plumes in a Highly Permeable Aauifer Groundwater y 12 no 6 1974 pp 388-393
28 Klefstaa G Senalein LVA ana RC Palmauist Limitations of the Electrical Resistivity Method in Landfill Investigations Groundwater V 13 No 5 1975 pp 418-427
29 Landon RA Application of Hydrogeology to the Selection of Refuse Disposal Sites Groundwater V 7 no b 19b9 pp 9-13
30 Lang SM Bierschenk WH ana WB Allen 1960 Hyaraulic Characteristics of Glacial Outwash in Rhode Island Rhode Islana Water Resources Coordinating Board Bulletin No 3
31 LeGrand HE Patterns of Contaminated Zones of Water in the Ground Water Resources Research v 1 No 1 1965
32 Palmauist R and L Sendlein The Configuration of Contamination Enclaves from Refuse Disposal Sites on Floodplains Grouna Water v 13 no 2 1975 pp 167-181
33 Pinder GF A Digital Model for Aauifer Evaluation Techniaues of Water Resources Investigations of the US Geological Survey Bk 7 Cl 1970
34 Purushattam D Tamxe GR and CM Stoffel Leachate Production at Sanitary Landfill Sites ASCE Environmental Engineering Division Journal V 103 no EE 6 Dec1977 pp 981-988
35 Remson I Fungaroli AA ana AW Lawrence Water Movement in an Unsaturated Sanitary Landfill ASCE Sanitary Engineering Division Journal v 94 no SA2 April1968 pp 307-316
36 Rosenshien JS Gouthier JB and WB Allen Hydrologic Characteristics and Sustained Yield of Principal Ground-Water Units Potowamut-Wickford Area Rhoae Island USGS US Government Printing Office GS 67-324 1968
37 Roux PH and B Vincent Electrical Resistivity Evaluations At Solid Waste Disposal Facilities US Environmental Protection Agency SW-729 Cincinnati Ohio 1978
124
38 Salvato JA Wi lk ie WG and BE Mead Sanitary Landfill Leaching Prevention and Control Water Pollution Control Federation Journal v 43 no 10 Oct 1971 pp 2084-2100
39 Sawyer CN and PL McCarty Chemistry for Environmental Engineering McGraw Hill 1978
40 Stellar RL and P Roux Earth Resist ivi ty Surveys - A Method for Defining Ground-Water Contamination Ground Water v 13 no 2 1975 pp 145-150
41 Todd OK Ground Water Hydrology John Wi ley and Sons Inc New York 1959
42 Tolman AL Ballestero AP Beck WW and GH Emrich Guidance Mannual For Minimizing Pollution From Waste Disposal Sites US Environmental Protection Agency-500SW-677 Cincinnati Ohio 1978
43 Trescott PC Iterative Digital Model for Aauifer Evaluation US Geological Survey Open file report 1972
44 University of Rhode Island Academic Computer Center CalComp Contouring Manual
45 Warner DL Preliminary Field Studies Using Earth Resistivity Measurements for Delineating Zones of Contaminated Ground Water Groundwater v 7 1969 pp 9-16
46 White EF A Report to the Town of S Kingstown Utility Survey Engineering Corp 1967
47 Zohdy AAR A Computer Program for the Calculation of Schlumberger Sounding Curves Over Horizontally Layered Media Using the Method of Convolution US Geological Survey Denver
48 Zohdy AAR Eaton GP and DR Mabey Application of Surface Geophysics to Ground-Water Investigations Technidues of Water-Resources Investigations of the US Geological Survey Book 2 Chapter 01 Washington US Government Printing Office 2401-02543 1974
N
^ooo
feet
Fig 1 Location Map
3
peoy ||H asoa
X ltbull
Alt
f c c
o
^ ^ o o f a
O OJ 83X1
o O
x o
seepage observation -t West
hole Landfill Area
Legend mdash landfill limit bull j--excavation limit r^-s stream copy WNWNEECSeuroSCSEN
monitoring well locations = = = unimproved road
A contaminated domesti supply well
D uncontaminated domestic supply well
feet
Fig 3 Supply Well Locations
5
a 03
N lo ^ gt
laquo c 2
mdash w
3
X o ^
3 O L
o CO
0 opound E bullo
0
co
c
o0
uj ^
0 o o c
o $ bullA
E c o
w
bullo t_hraquo9 O
_OplusmnJ ca
u
pro
ve I 51 H
bullo 0gt
UJ _c e poundbullo Mzbull w gt 0
laquorege cc
0gt -^^ o a5 raquobull bullo o sect 3 mdash laquoo o wcz _
3Ogt c $c o_ X
aw e 05 0 (0 3 bullo
o a 2 2 u
hydraulic properties and the subsurface geometry enable estimates of
ground-water outflow to be made Streamflow measurements were used
to verify these outflows Contamination levels using specific
conductance measurements as an indicator were measured in wells
streams and observation holes to help delineate the extent ana
degree of contamination An electrical resistivity sounding was
conducted in a known contamination zone
The primary objective of tnis study is to determine flow
patterns in the vicinity of the landfill ana recommend possible
actions to contain or minimize the impact of the contamination In
oraer to fully evaluate these goals the aforementioned parameters
were input to a computer model to produce simulated flow patterns
under different conditions The simulated present conditions were
matched with field water table and stream flow measurements to
calibrate the model A series of simulations were then run to
evaluate flow conditions before the excavations anaor landfill
existed Remedial measures such as reducing recharge to the
landfill and implementing a slurry wall to blocx off leachate flow
to endangered wells were simulated to evaluate their effectiveness
Based on this analysis recommendations are made as to how to
minimize leachate production ano best alleviate the immediate danger
of the contaminant plume spreading to unpolluted domestic supply
wells
background
The South Kingstown landfill is in a geologic setting that is
very similiar to the nearby West Kingston landfill This is located
about 3 miles west of the South Kingstown landfill and has been
studied to assess leachate effects on groundwater quality using
specific conductance as an indicator of contamination levels
(222ltt) Both sites were located in abandoned gravel Quarries which
were filled in with refuse to create the landfill
In the literature numerous authors have shown that the character
of contaminant plumes from landfills are largely dependent on the
local geology and geohydrology A study on Long Island (27) in
similiar glacial material illustrates that the Quantity of flow is
dependent on the hydraulic conductivity of tne aauifer the
hydraulic gradient and the vertical cross-sectional area of the
aauifer it flows through This is expressed as Darcys Law (41)
Q = KIA
wnere Q = flow quantity
I = hydraulic gradient
K = hydraulic conductivity of the aauifer
A = vertical cross sectional area of the flow area
Specific conductance was used as a contaminant tracer to show that
the plume from the landfill flowed downgradient and vertically
through the full thickness of the aauifer A study in Iowa (32)
indicates that the size ana shape of the contamination outflow from
a l a n d f i l l can be predicted from existing geohydrologic conditions
and that the horizontal shape of the outflow extends downgradient
8
from the source and parallel to ground-water flow lines Other
parameters which control the extent of the contaminant plume are
dilution and dispersion in the aquifer and the adsorption properties
of the aauifer material (31)
The amount of leachate generated depends largely on the amount
of water that infiltrates through the landfill to increase tne water
content of the refuse in the landfill The precipitation recharge
that percolates down through the unsaturated zone to the water table
moves in a vertical direction (35) Surface runoff soil moisture
storage losses and evapotranspiration account for tne precipitation
that is not transmitted tnrough the unsaturated zone of aeration
(3315) Upon reaching the saturated zone the water enters the
ground-water flow system Ground-water mounding has been reported
in landfills due to the decreased hydraulic conductivity of
compacted refuse relative to surrounding aauifer material (20)
Chemical processes within the landfill leachate outflow and
surrounding soil cation exchange capacity relative to water duality
of the surrounding aduifer have been studied in Pennsylvania (1) anu
in Delaware (5) A procedures manual for ground-water monitoring at
solid waste disposal facilities was developed by the US
Environmental Protection Agency (USEPA) (9)
Several reports have been written that investigate site
selection design criteria and remedial measures to correct
leachate problems (29) A survey of ground-water protection methods
for landfills in Illinois studies relationships to the water table
theory of liner installation and monitoring devices (13) Sanitary
Landfi11-Leaching Prevention and Control presents a review of
preventative methods such as means to minimize infiltration
interception of ground-water and other pollution control measures
(2 37) A study in Pennsylvania on actual measures implemented to
collect and treat a landfills leachate discharge presents a site
specific study (19) Leachate Quality Improvements After Top
Sealing1 shows that by minimizing infiltration at a landfill in
Connecticut the outflow leachate water quality can be improved
dramatically and contamination plume reduced significantly (6) The
most comprehensive reports on remedial approaches to upgrading waste
disposal sites and ground-water protection methods have been
compiled under USEPA contract (1542)
To assist in evaluating remedial measures the US Geological
Survey (USGS) computer model Iterative Digital Model for Aduifer
Evaluation was used It was originally developed as a model for
simulating two-dimensional aauifer problems (33) It had been
updated since its original development to accomodate different
options (43) This model has been applied to glacial outwash
regions in Rhode Island (717)
10
Description of Study Area
A map of tne landfill area (Fig Z) was obtained from tne town
of South Kingstown The excavation to the west of Rose Hill Roaa
the landfill area directly to the east and the presently operating
area to the east of the central stream comprise tne overall study
area This study will concentrate on the west landfill area whicn
has recently reached capacity and been closed to further dumping
This site received mixed refuse for the past 15 years The depth of
the excavation where the landfill presently exists was approximately
to bedrock in some places Tne exact depths of landfill material is
unknown
The landfill cover has been graded and sloped generally eastward
to convey surface runoff to the eastern side A sandy soil that was
excavated locally was used as tne cover material The northern
section has a vegetation cover and the recently filled southern
section has been seeded and mulched The six monitoring wells W
NW NE EC SE SC were placed by the town of South Kingstown to
provide water quality information
Referring to Fig 2 the west excavation stream drains the area
created by the excavation to the west of Rose Hill Road and flows
throughout the year The central stream drains a small watershed
area which lies to the northwest of the landfill and drys up during
part of the year These streams flow into the Saugatucket River
which flows throughout the year and is larger than the west and
central streams combined
11
The USGS Groundwater Map (18) was initially consulted to proviae
information on the ground-water flow patterns (Fig 5) and the
geology of tne area (Fig 6) The surficial geology borings and the
vertical geologic cross-section at the base of the study area
indicate shallow water table and bedrocic and a nearly constant
saturated thickness (18) Boring logs at the W well ana a point
approximately 150 feet south of it indicate glacial outwasn material
which is primarily sana with a trace of gravel over bedrock at a
depth of approximately 33 feet Borings at the east landfill area N
and S monitoring wells indicate the same aquifer material
(Appendix B)
The ground-water map developed by Hahn is taken as
representative of conditions existing prior to the excavation of the
I l andfill (18) This indicates water-table contour lines that run in i
a general northeasterly direction This means tnat flow was
originally in a southeasterly direction However contamination of
domestic supply wells on the west side of Rose Hill Road has
occurred (Fig 3) strongly suggesting that the original flow pattern
has been altered by the excavation to the west of Rose Hill Road and
the landfill to the east of it Domestic supply wells were formerly
located directly to the west of Rose Hill Road but were aoandoned
when they became contaminated from landfill leachate New wells
were located to the south and west away from the contaminant plume
of tne landfill In addition a well located at the northeastern
corner of the landfill was contaminated and a replacement located to
the east of Us former location on tne opposite side of the central
12
Legend scale 124000
mdash-40 mdashground-water contour elevation
Fig 5 Ground-Water Map
13
Legend feet
TILL
Fig 6 Geology Background Map
14
stream This second wel 1 also became contaminated Domestic supply
wells located near tne northwestern corner of tne landfill and
approximately 300 feet south of it nave remained uncontaminated
These well locations serve as an indication of tne extent of the
landfill contamination which is largely dependent on the groundwater
flow patterns To furtner investigate this problem and provide
substantial information on which to base the geohydrologic analysis
field studies of the area were conducted
15
Field Studies ana Procedures
A map of the lanafill and an aerial pnotograph of the area were
obtained A tracing of these maps superimposed upon another
delineates stream landfill and monitor well locations (Fig 2)
The field investigation concentrated on the west landfill area ana
its aajoining streams ana monitor wells The east landfill area and
the three monitor wells in that area are induced in the latter
phase of the study in oraer to expand the model area
A traverse which establishea tne monitor well elevations was run
using a Carl Zeiss level These were originally sitea in by the
town of South Kingstown using a local USGS reference datum number 40
(18) The wells of known elevations then served as benchmarks for
referencing adjacent stream elevations This in combination with
the depth to water table measurements at each well enables tne
water-table surface geometry of the area to oe visualized
Water-table measurements of the west landfills wells were recordea
over a ten month period to record fluctuations (Fig 7 Table 1)
The east landfill areas wells were monitored for a five month
period Using a given water-table condition a ground-water map was
developea of the area (Fig 4) This indicates an outflow from
the landfill primarily in a southeasterly direction and partially
in a southwesterly direction
Additional bedrock and water-table information was ootainea by a
seismic refraction survey at several locations along the landfill
perimeter A Bison Model lb70C Signal Enhancement Seismograpn was
used to maxe the surveys Lines were run (to a length of kOO feet)
16
17
w s p bdquo S bdquo s S S a laquolaquo _
s 2 8
V
r bdquo
3 s a
-R s
S
S 3
t
raquobullraquo
S
5
K
r
~
3
K
pound
7
S
bdquo3
C 5 S
shy raquo S s
1 3 s 3 2 5 ^ bull
5 m
s o
^ 3
raquo
--
R bull 5
s pound J O s
5 a 3 7 3 m
5 s a ^
iraquo a s rlaquo
M ^
^ c o 2 5 s 3 a S R
rd 3 y a O =J
^ bdquo
JJ s s 3 bull ~ I
~ s 5 3 a s a
(Ogt (U
2
-t =
r s s in
5 y
a s
5
3
s
5 a
^ a
3 a 51 a bullbull
sj 5 Ml
3 a bull
s raquo
a
0)
0
^ mdash
a j -
-3
C
g S
S
bull a
-
~ 3 o
2 s s 3 a bdquo s s $ Al s
(1) = $ s 3
S
c a a
3 e 5 s N s S a - 3 = s s a 5
a s s - 3 S shy
4
0
a s
bdquo tfH
bdquo
3 a
bdquo
s a
e bullfl s i s s a s a
3 nt
s s 3
g laquo s3 a
~ J s 2 a s o s S s 3 a a j laquo s o s
3 bull laquobull
2 a 7 3 a 3 a ^2
s mdash 5i o
bull bull
mdash
3 o
ss a
fc mdash
3 1-sect m ishy n
18
in both directions to provide a check and permit accurate estimates
of the depth to bedrockThe seismic results allow approximate
interpretations of the depth to the water table and bedrocK thus
permitting an estimation of the saturated thickness Ground
elevations at the location of the seismic surveys were determined
from a topographical map and field siting From this information
water table ana bedrock elevations estimates were made Bedrock
contours are listed in Fig 8 In addition a table which
summarizes the seismic refraction results for the unsaturated
saturated and bedrock layers velocities and depths at each survey
location is presented in Table 2
Scream gauging stations were established on the two streams
bordering the west landfill (Fig 9) Three stations were placed on
the central stream These provide information on the influent or
effluent condition of ground-water flow in the upper sections of the
stream and ground-water baseflow from an area adjacent to the
landfill into the stream (Table 3)
The stream gauging stations used were 90deg V-notch weirs The
weirs located in the SE and SW positions were placed in the
streamoea with a liner of plastic upstream to minimize underflow
The weirs located in the NW and E positions were cut to fit in
recesses of concrete culvert pipes Concrete plywooa interfaces
were coated with roofing cement to minimize bypass flow Upstream
water pressure and a snug fit hold the plywood sections in place
All weirs were implaceo according to AigtTM reouirements and flowrates
calculated using the standard 90deg V-notch formula (3)
19
N
seepage West observat ion Landfill hole
Area
Legend landfill limit excavat ion limit
copyWNWNEECSESC monitoring well locations
= = = unimproved road -- WNES-number
seismic refraction locations
-40shy approximate bedrock contpur elevation
feet
Fig8 Seismte Survey Location
20
c ^-^ c4j ^laquoc in -=r 3shyjj bull pn f- 4-gt bull in in OjJ bull bull a jo bull bull O JJ
co CM o on on CO CM CTNVO VO co CM o on on Q gt_x rH oj on a oj on a - rH oner
rmdash on sr i i
M z Z
gt gt gt
X-N CO laquomdashv CO CO bull igt gt bull
1 gt fc^gtgt bullbull ^ ^ ^
C 4-gt O t igt O J- 4J O H m o o o 3 bullH CO O rH in 3 bullH co vo o in 3 ~ 1 i-k -i ^trade fj rj ui ij o CO o n o rH =r co o n vo vo vo co o bullv O O O
O raquo On-3 rH O -bull- rH ON in _ IH in oj - rH bull rH VO OrH bull rH On ON pH d)u CO -UCO 4J OJ CO 4-gt gt
C mdashbull gt CM gt CM H-l O CO
v- ^^ N C 0
bull0 N CO
4-5 -0 _c^gt in in CO CO
C x~ c -^ t-oo in i 4J j_gt 41 4J bull 9 bull bull 4J bull
o j ON O O 3 (0 O4J O ON ON QJJ t~-^3- OJ 4-gt L
CO CM trade CO CM rH rH OJ co CM oj on Q ^ _ CO 3~Q-- n 45 Q mdash OJ OJ OJ C (0
1 11 3 nZ 2CO
gti gt gt CO CO CO ^-x m -s CO
rH rH ^ ro^^ bull gt bull ^ igt gt bullgt gtgt bull r O -Q 4Ji JJ O 5- JJ O pound- ^ O 4) oj o on (0 CO
3 bullH CJ O O in 3 bullH CO Cmdash VO on 3 pound-laquo H CO o n in inco co o n ma- r co g^ 5sect^ o
o rH on oj O bull- rH ONCO L O_ rH OJ VO M
rH bull rH =t rH bull - OJ T CO CO M CO 4-gt rH CO -U rH CO 4-) s
uits
CO 4-gt 4-5 T3 gt CM gt CM gt CM cc CO CO CO
3 3gt oa tlp^ CO O CM O gt 4J O 40 i 3 r+ k C pound JS
CO pound
^^ s -bullgt cmdash on poundZ VO CTI trx 4J 4J 4J
) bull bull bull Q Q Q Q4J 3shyc O-JJ CTgt OJ OJ Q-IJ inco on CO CO CO o co CM oj on co CM oj on co CM on
Q Q QON^ Q bullH Q^
rH rH 4J rH
O bullraquo L Z bull CO CO CO
i gtgt rH oj on gt tgtshyCM ^ cO^-s CO ~ CO
CO CO J X fc^_ bull^gt bullgtgt bull gt gtgt bull gt CO
j_ jJ O pound- Jj -P O Li deg =fObullH co on f- ^ 3bullH CO CO O in 3bullH CO
g^ -^2
poundsect HO
eis
mic
3 CO in in in in in in co o n co o n
o -^ r oj in O rHCO CO rH bullrH bull rH =T OrH bull rH OJ f-CO 4J bull- CO 4J rH O0) J-)
gt CM gt CM gt CM 4J
CO N_^ m^
bull OJ
t t poundshyCO CO CO CO rH J3 gt r-t oj on gt r-i oj on gt gt r n o j o n
lto co lto CO T bull ii-4 laquomdash bullmdashH
bullo CO L L 0)
CM CO cc
21
N
545-594
seepage observation
hole West Landfill
0NE I47-509
Area
Weir 45
i487-531
0 EC Al3-467
Legend bullmdash landfill limit -bull---excavation limit r-s stream
copy WNWNEECSESCSEN monitoring well locations
= = = unimproved road
Weir location and elevation
feet
Fig 9 Weir Locations and Wate r Level Ranges
22
JT NO
S shy S
O
bull ry m
oa
NO
(M raquo 1 03 or NO m
JT O O raquo
O NO 03 (j
PW tn in ^4 fraquo
m CN) f O O (M Oj
mdashraquo 3 M
s cshy -raquoraquo
o in in ^
rjO
laquobull NO ON
o bull-lt ^
H fy (NJ
tjgt
1 4 03 O
o
o
03 CM
in0
0
7 raquo
9gt
IM i iev NO
i in
i ru
i 0 rsi -or^
sO NO
CO O
03 raquo
1 O3
pound o ro CNJ
03
tn B OJ
o 03
m oi
NO
(M
r
(M
CO i M 03
m N ltn ~+ ltM -
QJrH
O M O ^ ^r-
oo m
8 a
m
^ NO
8 fNl
rshy03n
m - in
o laquoO
bull3 as m o 03 03 4
i O
i ^
shy
O
ltM bull^
ON f tn H 1 4 raquo4 i-4 H P-t
^^ lt-l
r-laquo
^ 1 1 1 1
pound raquoraquo O)t o gtz
bull bull ltbull
lt2
1 pound OJ
3 oi g bull
pound
1 pound laquolt bull
3 bull o a
pound
5 laquo15
f bull 3 Jl s
5bull 1 5
23
A field study to determine the infiltration capacity of a
section of tne landfill topcover was conaucted A modified version
of a double ring infiltrometer was used to study infiltration rates
(4) The cylinder diameters useo in this study were 8 inches and 18
inches A constant head of 6 in was maintained in the
infiltrometer and rates of infiltration were determined Tnese
results and an analysis of surface infiltration into the landfill
are included in tne analysis and discussion section
Specific conductance levels in the monitoring wells in the
streams bordering the landfill and at observation holes near the
landfill were measured (Fig 10) This is a good indication of the
mineralization of water (39) Specific conductances were measured
intermittently over the ten month period to develop a picture of the
extent and degree of contamination in the wells (Fig 11 Taole4j
and in the surface contamination monitoring locations (Fig 11
Table 5) A comparative standardization of the Beckman (short and
long probes) and YSI specific conductances is in Appendix C
A surface electrical sounding using the Schlumberger array was
conducted adjacent to Rose Hill Road at the R-l location (Fig 12)
in an attempt to delineate the vertical extent of the contamination
zone Well W was used as a centerpoint and a reference for
water-table depth pore water conductivity and depth to bedrock A
Schlumberger array electrical resistivity sounding was also
conducted in an uncontaminated area at tne R-2 location (Fig 12) to
provide a comparison background interpretation A seismic
refraction survey N-4 was conducted at the same location (Fig 8J to
24
N
excavat ion
Seepage West observat ion Landfill hole
Area
Stream 1 Seasonal observation 0 EC
hole
East Stream2
Legend sw Weir landfill limit j--1--^ excavation limit
copyWNWNEECSESC monitoring well locations
== unimproved road
feet
Fig 10 Surface Contamination Monitoring Locations
25
8000T
7000
O bull U) W6000
Legend
0 sc A NE O W
A SE O N W
a EC
1 O N D J F M M
Time months Flg11 Flucuatlon In Specific Conductance in Wells
26
Table 4 Specific Conductances in Wells (pmhoscm at 25degC)
West East Landfill Landfill
Date NW NE EG SE W SC N E S
81581 851 938 236 2356
102981 171 3268
11381 3268
111081 304 988 1100 258 3800
111481 426 2736 1216 186 4560
111781 304 3610 433 389 4560
121981 380 1406 129 103 380
1982 160 152
31582 274 760 1064 61 334 8000+ 182 53 84
52182 450 1500 1125 112 712 8000+ 175 255 150
52282 425 1320 1200 110 850 180 320 170
27
O
ct c r i c o o o o o c M o m o in CO CM unp^
3bull t- fmdash o^ co tmdash vo co in co cmdash co in a
bull bull1 1-1 trade4 rH rH^ CO 4)2
~ plusmn4J o O CM ^_
o n CO vO J oraquo 0C0M
cu rH rH rH rH rHin tmdash
3 iCM 4J
^j CO CO
E O0 ltU -H n o c E
See
pag
se
rva
t
rH O in 0 0 O O 0
O o x rH Cmdash
0 0n
cu rH mdash O tmdash X o o o o c o o o o r H r H i n o i n i n o O
bull L in oo co oo oo o cy cr o rH CM o cr ONc fcJ bullH on en m m rn c^n rH rH rH0 pound CO 3 CO
t CM0gt s o o o in rA n ^o oo in tmdash oo 0gt zr =r a- JT JT$_
T)C CO
~ E CO ^ _bdquo ltu CO g r H r n c n i n o o r H r H
vgtO ^D O ^^ ^O CO ^^ ^^ JJ 2 4) rH rHCO t
c CO
CO c 9) rH 0
CO -^ C c CO ltuo famp O trade t iH
0
bullo co n ^
oS
o ^^ bullH m
i co rn O CQ O1 CO CO 4) c2Q 3
CO
mdash^ bull cmdash CMin 1 gt rH vO vO O CTgt CO
s CTgt CO OO Ogt Craquo- tmdash cu O CO rH z 0
bull_bulllaquo
H bull L o in r in o oo in 3 rfy ff^ tir f^ CO C^~
4)bull
Z 3
^ ^ ^ ^ H r H r H r H r H rH r H C O r H C O a O C O a O a O C O C O r H i H r H CO OO - gt 0 0 ^ - gt ^ raquo - ^ ^ 1 - gt ~ gt - C O C O O O
U ^ raquo ^ - ~ raquo O ^ ^ O t ~ C O r H - r r ^ - ^ ^ JJ r H C M v O r H r H r H r H r H C M C M r H i n c r gt rH CO CM gt laquolaquo - - -^ bullmdash mdash bullraquoraquobullgt -v -v ^^
~ v O r H r H r H r H r H r H r H r H lt M C M C M CM O O r H r H r H r H r H r H r H r H r H r H r H r H rH
in rH cmdash
CO vo
CO vO
41 rH CO
CTgt rH raquo CM rH
cn CO
o 0 rn
CO cmdash
tmdash fshy
CM ao
iT rH
m
ogt ao
O o vO
CO t-
tmdash Cmdash
CM CO
rH CM
I
rH CT
O vO in
CTgt
in c^
CM ao
CM CM
in
-
bull
CO bO C bullH T3
cy ~
_
CJ E 3 ^ n c bullH
1-1
CO
^H
28
excavation
West Landfill
Area
Legend bullmdash landfill limit -bullbull--bullexcavation limit r~~s stream
copy WNWNEECSESCSEN monitoring well locations
= == unimproved road
electrical resistivity sounding
feet Fig12 Electrical Resistivity Sounding Location
L
29
allow estimates of depth to water table and bedrocic to be made
Soundings were carried out to 500 foot electrode spacings to insure
that hredrock was penetrated and to facilitate interpretation These
results and a discussion of the soundings interpretation are
included in the analysis and discussion section Schlumoerger
resistivity soundings were made using a Soiltest R-bO unit
30
Model Development
The USGS Iterative Digital Model for Aauifer Evaluation was
usea to develop steady state flow models of the study area (43) A
flow chart of the computer model and a brief explanation of the
subroutines usea is presented in Appendix D The stream locations
elevations and aauiferlandfil1 geometry and hydraulic properties
were input to the model to compute head values at each 200 foot
grid spacing node (Fig 13) The input data which is for the
existing excavation and landfill conditon is listed in Appendix E
The head values that are computed at each grid space are in turn
loaded into the CalComp plotting routine (44) where a grid spacing
is setup with the computed head values at each node The contouring
program linearly interpolates between these head values and
generates a contour map The computer simulated ground-water
contour map for the excavation and landfill is presented in Fig
14
The streams in the model generally serve as controlling boundary
conditions When using computer simulated geohydrologic models of
an area choosing the boundary conditions for the model that are the
same as prevailing conditions in the field is a critical step in
model development Extending the models boundaries to areas in the
field that have a minimum influx of ground-water across them
simplifies the proolem of calculating fluxes from outside the model
area The eastern boundary is bordered by glacial till which has a
low hydraulic conductivity estimated to be 67 ftday(2) This
contrasts to the high hydraulic conductivity of glacial outwash that
makes up the model area of approximately 107 ftday(3036j
31 N
o 9
bullO O
32
33
The Saugatucket River serves as the controlling boundary on the
east A small drainage area directly to the east of it provides a
minimal influx
Beyond the moaels northern boundary the glacial outwash valley
extends to the base of a till covered h i l l on the western half ana
on the eastern side extends along the Saugatucket stream Due to
the relatively large drainage area that lies upgradient from the
northern boundary a recharge flux eduivalent to 10 inyr over the
drainage area on the till hill and outwash area north of the model
area was input as underflow (Fig Ib) Part of this was input at
each northern boundary node Till has a lower infiltration capacity
than outwash so more of the precipitation w i l l be transmitted as
overland runoff resulting in a lower ground-water baseflow The 10
inyr of recharge that results in a ground-water inflow from the
combined till and outwash region represents an estimate that is
smaller than the 14 inyr recharge for glacial outwash areas in
Rhode Island (25)
The glacial outwash valley extends beyond the western boundary
No significant ground-water recharge flux was estimated at this
boundary A relatively low ground-water gradient exists to the west
of this which does not provide a significant flux across this
boundary Tne southern boundary is basically the outflow region for
the area and therefore would not reauire any ground-water flux into
the moael area across this boundary This boundary was set south of
the point that the streams in the model merge together Therefore
the streams which lie to the north of it are the controlling
34
scale 124000
Fig 15 Northern Drainage Area
35
boundary conditions The flux out of the downgradient outflow
region approximately eauals the influx from precipitation recharge
and boundary influxes
When tne stream configuration in the moael area are reviewed it
can be seen that they comprise a large portion of the boundary
area The screams can act as sources or sinks for water in the
model thus providing to and removing water from the aquifer The
leakance option was used in the model which provides for a confining
bed and aouifer area beneath the stream to be input
The leakance is defined as the hydraulic conductance of the
streambed divided by the streambed thickness which in this case is
taken as 1 foot The leakance value at each streambed node
restricts the flow between the aduifer and the stream The
streambed hydraulic conductivity is typically 01 the value of tne
hydraulic conductivity of the aduifer (717) The value 107
ftday was used for a streambed conductivity based on a value of
107 ftday for the aquifer The aduifer and stream hydraulic
inputoutput exchange at eacn node is calculated by initially
finding the difference between the initial field stream head
elevations and the computed head elevation values at the
corresponding nodes This head value is then multiplied by the
(Leakance value at each node) x (stream area of each node)
Therefore if the aduifer head was lower than the stream head the
stream would act as a source of water for the aquifer and vice
versa
36
Tne leaxance input at each stream node is the ratio of the
actual field streambed area in each node to the area of each node
which is 200 ft x 200 ft = 4 x 104 ft2 The west
excavations stream width is approximately 3 ft central 4 ft and
east 5 ft Therefore if tne west stream traverses the node
directly without meandering it presents a leakance of 3 ft x 200
ft4 x 104 ft = 015 Leakance and streamhead values were
input at each node to set up the stream flow parameters in the
models
A recharge value of 14 inyr over the entire area was input at
each node This represents a value of precipitation that is
transmuted into tne ground-water rather than being directly
evaporated evapotranspired through plants or overland flow
runoff The precipitation recharge flow from the stream into the
aauifer and boundary fluxes provide the model witn input flow
parameters
From analyzing the available information it was determined that
the study area lies within a glacial outwash area with a relatively
shallow bedrock The seismic survey around the landfill generally
indicates a depth to bedrock below the land surface of approximately
29-43 ft with corresponding saturated thicknesses of 19-33 ft as
seen in Table 2 This agrees with borings from tne USGS groundwater
map in the stuuy area (18j The seismic survey was run at a low
water table condition which was several feet below the high water
table level (Fig 9)
37
High water-table saturated thicknesses were used to develop
model parameters For the purpose of this model study the saturated
thickness was set at 30 ft except in the vicinity of well W where
there is a bedrock high (Fig 8) At this location a high water
table saturateo tnicxness of 8 ft was estimated In tne vicinity
the seismic survey was conducted the bedrock elevation at this
location is the highest and the saturated thickness the least Tnis
can be seen by an east-west cross section of tne landfill (Fig 16
The boring log for well W indicates a sand trace gravel outwash
material (Appendix B) Boring logs at the eastern landfill area N
and E indicate similar material On this basis the hydraulic
conductivity was estimated at 107 ftday (3036) Witn the
exception of the landfill and the bedrock hign areas the
transmissivity values were set at 107 ftday x 30 ft = 3210
fto day From the literature the hydraulic conductivity of the
landfill material was estimated at I ftday (19) The
transmissivity of the landfill material in tne nortnern section was
estimatea at 1 ftday x 30 ft = 30 ft^day or approximately two
orders of magnitude lower than the outwash In tne landfills
southern section the original excavation was not as deep as in the
northern parts The landfill material was estimated to makeup only
one half tne saturated depth the remainder being the original
glacial outwash material (Fig 17) Therefore the transmissivity
at the southern end was estimated at 15 ft x 107 ftday + lb ft x
1 ftday = 1620 ft^day These values were graded into the 30
ft^day values at the landfills northern halfway point These
38
were input as transmissivity values to the model at their respective
locations This model did not use the water taole option so
water-table fluctuations did not affect the transmissivities
39
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Model Calibration
A simulation was run using the initial estimates of stream
parameters aquifer and landfill hydraulic conductivities
transmissivities boundary and recharge conditions to approximate
water taole conditions in tne fiela Initially the existing
condition of the excavation area to tne west of Rose Hill Road and
the landfill to tne east were modeled in order to calibrate the
model to current field conditions as shown on Fig 4 The simulated
well values (Fig 14) fall within tne range of field values (Fig
9) The resulting contours also provide an approximate matcn This
can be seen by comparing Fig 4 with Fig 14 An additional check
was to match the flow loss and gain in the streams between tne weirs
in the central stream which w i l l be discussed later The
simulated flow value from the excavation drainage stream is the same
as that measured at the SW weir location Having calibrated the
model by approximately matching well water levels nead contours
and scream flow values different field conditions and possible
remedial measures can be simulated
When the model grid was laid out over the study area as viewed on
Fig 13 the stream configuration rarely traversed the grid nodes near
their central axis When the stream locations were input to the
computer the information was documented as crossing the central axis
of the grid nodes The result of this is a slight aberration when
the actual stream configuration is laid over the computer graphics
head contour output The streams dont always cross the groundshy
water contour at the logical location Rather than modifying the
actual stream configuration to adjust then to the computer output
their actual locations are presented
42
Simulations
i The primary focus of the computer modeling is to analyze flow
patterns under changing conaitions in the near vicinity of tne raquo
landfill The study areas overall flow patterns as they exist
today are first presented in order to realize the lateral east-west
head contour lines between the stream that directly borders the
landfill on the east side and the SaugatucKet stream (Fig 14)
This indicates a general southerly flow direction in that area As
different conditions are modeled these contours generally maintain
their east-west orientation In order to facilitate interpretation
of flow patterns in the near vicinity of the landfill flow patterns
to the west of the stream that borders the east side of the landfill
r are presented in the subseauent models
L- Natural Conditions
The results of modeling the original natural conditions are
shown in Fig 18 The excavation and stream to tne west of Rose
Hill Road and tne landfill did not exist in this simulation The
southwestern boundary consists of a drainage stream that was
delineated using an aerial photograph and stream elevations were set
using the topographical map The USGS ground-water map (18) was
used to estimate head values between the west excavation and north
streams These were input to the model as constant heads on the
models western boundary The resulting simulation generally matches
the southeasterly flow direction that is indicated on the
ground-water map (Fig 5)
A3
Legend
x-^- stream 400 = = = unimproved road
I f ee t
Fig 18 Natural Conditions
44
Excavation Without Landfill
The condition of the excavation to the west of Rose Hill Road
with its resultant drainage stream without the landfill was modeled
next (Fig 19) The extent of the excavation ana the location of
the new drainage stream were delineated using the aerial
photograph The west stream elevations were sited in the field and
used in the model The concept of a confining streamoed layer was
excluded in tne excavation drainage stream under the concept tnat no
significant organic layer had been built up within the 25 year
period that the excavation had been initiated Head values between
the west and north stream boundaries were interpolated and input as
constant head values on the northwestern boundary The west
excavation drainage stream creates a condition that alters the
natural ground-water flow patterns by creating a more southerly flow
condition the drainage stream providing a more immediate surface
outflow in that area
Landfill Without Excavation
The hypothetical case of a landfill without the excavation was
modeled next (Fig 20) The low hydraulic conductivity zone of the
landfill changes the natural flow conditions and creates noticeable
mounding This is evidenced by the decreased spacing of the head
contour lines and deviation from the lateral contour lines of the
natural conditions and higher head values (Fig 21)
45
Legend
excava t i on s t ream
400 unimproved road
f e e t
Fig19 Excavat ion without Landfill
46
Legend
landfill limit
bull - s t ream 400 copy WNWNEECSESC
monitoring well locations f ee t bullbull-bull=bull unimproved road
Fig 20 Landfill without Excavation
1
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bull
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bullo 9
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CM
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48
Landfill ana Excavation
The condition of tne existing landfill and the excavation with
the dam is the next condition modeled (Fig 22) The ground-water
elevations used to calibrate tne model correspond to an actual high
water table condition Between the NVJ and pound weir a streamflow loss
of approximately 102 gpm occurs aoout 60 percent of this flow is
lost at the dam site which maintains a head of b-6 feet over an area
of approximately 1800 feet^ This approximates a field value of
1144 gpm influent to the aduifer between the NW and E weir on ]2
December 1981 (Table 3) From the E weir to the SE weir a net
increase in flow occurred of 74 gpm which corresponds to field
increase of b62 gpm
The surface runoff from tne landfill flows primarily toward tne
eastern side of the landfill Increases in water-table elevations
on the eastern side after heavy rains such as the 11 November 1981
storm indicates that this runoff increases outflow gradients to the
stream and therefore increases streamflow Surface runoff input is
not modeled which explains in part why field stream inflow values
are slightly higher than model predictions especially for periods
after a storm has occurred The flow from the SW weir located at
the southern end of the excavation represents drainage outflows from
that area The net flow calculated in the model was 140 gpm
which approximates field conditions of 1642 gpm on
December 9 1981
49
d f l f reg N E
shy
Legend
landfill limit -bullgt-bullgt- excavation ^-N_X- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road
-40mdash approximate groundwater contour
400
feet
Fig 22 Landfill and Excavation with Dam
50
The modeled flow patterns suggest how the various contamination
zones around the landfill have developed to their present state
They indicate a flow to both the southeast and southwest on their
respective sides of the groundwater divide Evidence of a
southwesterly contaminant flow is presented when the continued high
specific conductance contaminant level in tne observation seepage
hole is realized (Table 5 ) In addition the specific conductance
increase in the west excavation stream is evidence of an influent
contamination flow
Contamination flow to the eastern and southeastern side of the
landfill is obvious High specific conductance levels in the wells
on the eastern side (Table 4 ) a specific conductance increase
between the E and SE weirs (Table 5 ) and contamination in the NE
domestic supply well (Fig 3) present conclusive evidence of
contamination to the eastern side of the landfill
An anamalous condition that exists is a domestic supply well
located approximately 300 feet due south of the landfill remains
uncontaminated (Fig 3) Flow patterns indicate that contamination
would be transported from the landfill south to this area
(Fig 14) One explanation is that a pocket of clay at the southern
end of the landfill area was discovered in the original excavation
for the landfill (lt6) This evidently prevents leachate from
reaching this wells radius of influence
51
Summer Conaitlon
As described earlier during dry months of the year the stream
that normally borders the northern and eastern side of the lanafill
may dry up as far as a point southeast of the E well Tnis
condition existed from the 15 August 1981 to the 27 October 1981
period when streamflow commenced in the northern part of the stream
yet did not overflow the north dam until 17 November 1981 This
created the present day continuous flow condition throughout the
stream These summer conditions were modeled by removing the stream
above the aforementioned location while other conditions remained
the same (Fig 23) Summer condition well water levels listed in the
model generally match field low water table conditions (Fig 9)
Because there is no stream upgradient from the landfill to provide a
stream head and infiltration through the streambed groundwater
runoff from the area north of the lanafill is the controlling flow
input In these moaels an average recharge of 14 inyr was used
which represents a yearly average The summer recnarge conditions
are prooably lower given the effects of decreased rainfall and
increased evapotranspiration during the summer months A domestic
supply well whicn exists northeast of the landfill (Fig 3) nas a
greater potential to be contaminated from the lanafill at tnis time
than when the stream is flowing Flow patterns from the landfill
are such that during an upper stream no-flow condition groundwater
flow patterns are more in an easterly direction than in a
southeasterly direction The stream would act as a source of
infiltrated water upgradient from tne landfill and provide a
52
I ^N gt i I i j i -r- -bull- bullr -T- t- -r- i- TJ JV
bullbullT laquo ^ O - laquo bdquo xi cshy
H r^~ I -~- --^ X- = mdash x^ N
^--^ A bull O^NW -v - gt-bull Ni i I _____mdash - bull laquo l - mdashmdash 1 deg I ^ltv I C
I reg NE A
Js bull vbull A ~ - v T gt- ^ ix - N
-5Z- | N TfS lV I -bull bull iA i gt gt I ^ bullr-Ky L bull 1 _- copy]wgt-- - bull- mdash - - shy
= r Y ~mdash ltmdashA A
^^-lt A _ - - - - bull Hmdash - reg EC x ^-mdash mdash I ---mdash_mdash -t-V-^N - y
I- -bull - r x i X
V ^ 7 I -v (^~~^^r ^^^
sc Emdash-bull vV JI - - - ~ r )N y- -
X - bull r bulllt
^bull^ y y Jlaquo^ - -lt shy
T s^ lt^ ^ +^-b (
X
Legend
landfill limit j-j-bullraquobull excavat ion gt^ -x- s t ream
reg WNWNEECSESC monitoring well locat ions
= == unimproved road fee t
Fig 23 Summer Condition
400
53
constant head across tne northern section of the landfill This
would tend to orient the flow in a more southerly aowngradient
direction In addition the stream which flows adjacent to the
northeastern well could provide a source of infiltrated clean water
to it which would minimize the possible contamination from landfill
leachate
Without Dam
During tne spring scream flow condition the dam failure which
occurred between the 15 March 1982 ana 9 April 1982 monitoring
periods decreased flow to the aauifer and landfill This eliminated
the 5-6 foot head difference over a 19000 ft^ area which had
created a larger area and elevation head for infiltration to occur
The condition without the dam was modeled by reducing the area
encompassed by the dam to a 4 foot wide stream channel thus
reducing the leakance value at that node (Fig 24) The flow change
from the stream to the aduifer between the NW weir and E weir
reduced the model flow loss to 50 gpm Tnis corresponds to the 9
April 1982 monitoring period which indicates a 30 gpm loss
As compared to the previous flow loss in the upper stream
sections to the aauifer the 21 April 1982 and 22 May 1982
measurements between the NW and E weirs indicate a flow gain The
streamflow conditions have changed from an influent
stream-to-aauifer condition to an effluent aduifer-to-stream
condition that increases flow downstream
54
Legend
landfill limit j--i--i- excava t ion x-gtmdash^- stream 400
copy WNWNEECSESC monitoring well locations
= == unimproved road f e e t
Fig 24 Landfill and Excavation without Dam
55
Analysis and Discussion
In order to fully understand flow patterns and Quantify leachate
outflows at the landfill it is necessary to arrive at an estimate
of flow inputs from precipitation ana upgradient sources In the
following analysis it will be demonstrated that the rainfall input
to the landfill is the factor which controls leachate generation A
calculation using the H inyr recharge over the area of the
landfill was made to estimate the leachate outflow due to rainfall
infiltration An estimated 134 gpm is generated from the entire
landfill area Simulation of the existing conditions (Fig 24)
indicates a groundwater divide in the landfill is located
approximately at the western third Therefore approximately 23 of
the generated leachate flows to the eastern side of the landfill or
9 gpm The effect of the flow input from the upgradient stream is
evident when tne summer condition witnout the stream is viewed
(Fig 23) Without the stream to infiltrate the landfill and the
recharge and northern boundary condition as the flow inputs the
head at the northern end of the landfill drops about 5 feet from its
previous value A flow pattern from the north central part of the
landfill to the eastern side indicates a 12 feet head difference
with recharge - but with the upgradient stream a 16 foot head
difference occurs Considering the transmissivity change the
stream would increase the leacnate outflow from the landfill
approximately 43 under a low water table stream influent condition
to the aauifer This would increase leachate outflow to the east
side to approximately 129 gpm This value approximates the
56
outflow at the SE weir location during the summer monitoring period
when the upper stream was not flowing (Table 3) The outflow from
the western third of the landfill whicn lies to the west of the
ground-water divide would be approximately 63 gpm
Realizing the importance of infiltration to tne landfill as a
major influence on the generation of leachate an analysis of this
w i ll be discussed An estimate of infiltration was made using the
precipitation recora for October ana November (Appendix A) During
this time period a minimum of direct evaporation ana
evapotranspiration occured and the grouna is not yet frozen The
top cover over the lanafill is generally 05 ft to 2 ft of local
sandy soil and subsoil availability determined what was used The
top of the landfill is at an elevation of 92 ft as compared to the
ground surface at well W which is at an elevation of 76 ft
(Fig 25) This compares to the well W water level which is at an
elevation of approximately 52 ft This creates a long path for
infiltration through the unsaturated zone The topcover generally
slopes eastwara at a grade of 2-5 The west side maintains a
relatively steep slope of 10-15 ft drop within 50 ft ana the north
and eastern slopes have a more gentle slope of approximately 10 ft
within 100 ft distance An unlined surface arainage swale channels
surface runoff from the northern section of the landfill past the
NE well to the eastern side ana low area in the vicinity of the E
well This has a drainage swale to an area near the stream but
doesnt directly connect to tne stream A poorly graaed drainage
swale exists on the landfills left side The landfill material has
57
excavation
seepage observation ^
hole
Legend bullmdash landfill limit -^--excavation limit r^s- stream
copy WNWNEECSeSCSEN monitoring well locations
--- unimproved road O location of amp Inf i l t rometers O
feet
Fig 25 Infi ltrometer Locat ion and Drainage Feature
58
been placed in 10-12 ft cells and covered with 1 ft of soil at the
end of each day The material has settled differentially creating
areas for depression storage
An estimate of the percentage of precipitation that infiltrates
the landfill was made from precipitation records recorded well
elevations and an estimated specific yield for the landfill
material The volume of water that infiltrated should eaual tne
specific yield multiplied by the well water level rise Several
recharge periods were studied using this relationship Once the
percentage of precipitation that has infiltrated is determined the
percentage that is translated into runoff is simply the remaining
percentage if evaporation is neglected
From the literature for a slightly inclined slope of 2-5
typical runoff coefficients range from 10-20 in either sandy or
heavy soil (16) The landfill cover is generally sloping to the
east which creates a long path (approximately 400 ft) before the
runoff reaches the steeper slope on the eastern side of the landfill
of 15-20 The long drainage distance creates a greater time for
rainfall to infiltrate Another consideration is the actual
capacity of the soil to conauct water into the soil which was tested
in the field using double ring infiltrometers An average initial
percolation of 8 mmhr the first hour and a subseauent rate of b
mmhr occurred (Fig 26) The 8 mmhr rate compares well with
other sandy soil infiltration rates (14) Therefore if the
intensity of the rainfall exceeded a 5 mmhr rate for several hours
59
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E o
CO
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C9
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CO
CD CM
ogt CO N- to -4 CO CM
jq tuu i U O | raquo B J J | | J U |
60
on a poorly drained surface the additional rainfall would be
translated into runoff because the soils infiltration capacity had
been exceeded
The initial 8 mmhr infiltration rate was due to the pore spaces
in the sandy soil being filled and the subsequent 5 mmhr rate was
percolation into the low permeability landfill material The tests
were conducted in November assuming a minimal evapotranspiration
and the field capacity of the sandy soil had been maintainea
The W well was used as representative of the water elevation
changes in the landfill because it is directly adjacent to the
landfill 900 ft distant from the upgradient stream This minimizes
the effect of infiltration from the stream and maintains a high
contaminant level During periods of high runoff conditions excess
surface water ponded in a poorly graded drainage swale on the west
side and directly adjacent to the landfill This influenced the W
well at a time the contamination level dropped (Fig 11) Before
this occurence in mid-December the rise of the W well closely
matches that of the SC well and a background well SK6 which is
located outside the study area (Fig 7) Therefore it was analyzed
as a valia indication of the water level rise during the mid-October
to mid-December period The monitoring of the SC well was
intermittent due to inaccessaoility because of 10 ft extensions
being placed on the well as the refuse was being filled in arouna it
61
A high rainfall period from 14 November 1981 to 1 December 1981
was chosen for the initial study period The effects of
evapotranspiration were neglected due to the cool temperatures
experienced at this time Therefore it was assumed that the field
capacity haa been reachea and tnat any additional input to tne
unsaturated zone would result in direct percolation to tne saturated
zone During the time period 14 November 1981 to 22 November 1981
029 ft of rainfall fell and the well W rose from 488 ft to 493
ft - a 05 ft increase During the next 8 day period there was no
precipitation yet the W well continued to rise to 4972 - a 042 ft
increase The slow percolation of water through the landfill
material would account for the latent rise in the well water level
From previous reports a specific yield for refuse was estimated to
be 028 (1920) This value is dependent on the original compaction
of tne material age and resulting consolidation
During the 14 November 1981 to 1 December 1981 period 029 ft
of rain fell and the well increased 092 ft The following
relationship is used to evaluate the infiltration value and runoff
I = (Sy) h
Sy = specific yield
h = well rise
I = volume infiltrated
I = (028) (092 ft) = 0261 ft
62
The difference between the precipitation and the infiltration is
the runoff (assuming no evapotranspiration) Therefore 029 - 026 =
003 and furthermore 003029 - 13 runoff This corresponds in
the literature to a typical runoff coefficient for an inclined
surface of 2-5
Analyzing a longer precipitation period from 18 October 1981 to
1 December 1981 a net precipitation of 043 ft (accounts for
evaporation) occurred less 10 for runoff or 039 ft infiltrated
This results in a 139 ft elevation increase The well water level
actually increased 132 ft shy only a 5 deviation from the
calculated
From tnis investigation it is seen that a large proportion of
the precipitation has the potential to be transmitted into the
landfills saturated zone Exceptions are wnen heavy precipitation
periods exceed the soil percolation capacity frozen ground prevents
infiltration and direct evaporation and evapotranspiration recycles
the ponded surface water and infiltrated soil moisture back to the
atmosphere In retrospect water temperatures within the monitoring
wells could have been measured to indicate thermal effects from the
landfill on ground-water temperature Ground-water temperatures
were assumed to be 50deg F (9)
63
Specific conductance measurements serve as an indication of
contamination levels These measurements are used to trace leachate
movement which represents ground-water flow patterns Factors which
must be considered when monitoring pollutants are the attenuation of
the leachate contaminants which occurs both in the zone of aeration
and the saturated zone The former is a more complete process
Dilution dispersion and cation exchange are the primary factors
involved in decreasing leachate concentration in the saturated
zone The glacial outwash materials of southern Rhode Island do not
have a cation exchange capacity or a high buffering capacity so
attenuation is simply by dilution and dispersion (22)
The NW well consistently exhibits relatively low specific
conductance levels even though it is in landfill material It is
situated in a drainage swale and ground water elevations range from
543 to 5944 This is several feet below the upgradient stream
elevation of 64 feet which is less than 400 feet away The bottom
of the wellpoint is at an elevation of 5312 feet well into the
landfill material Infiltration from the stream to the landfill has
occurred at this location
The W well is situated on a bedrock high adjacent to the
landfill approximately 900 feet from the upgradient stream and its
water level is higher in elevation than the excavated pit (West
Observation Hole) which is 300 feet directly west The W well
maintains a contaminated level A poorly graded drainage swale to
the west of the landfill provides areas for extensive ponding and
infiltration to occur which explains the drop in conductance after
a high runoff period
64
The SC well is located in landfill material and has a
conductance of over 8000 umhos This indicates that leachate is
undiluted The oottom of the wellpoint is at an elevation of 389
feet which is situated in the landfill material
High specific conductance measurements in the west observation
hole and well W and their relative elevations indicate a
west-southwesterly flow direction from the landfill Infiltration
recharge and leakance from the stream into the landfill provides the
necessary elevation to cause outflow in this direction
Contamination from the landfill to the surrounding streams is
evident (Table 4) During the period 15 August 1981 to 27 Octooer
1981 there was no flow in the stream that Borders the northern and
eastern side of the landfill until a point just south of the E well
was reached High specific conductance levels in the EC and NE
wells were recorded (1000 jjmnos) At a point directly east of well
EC a pool of water existed that was relatively uncontaminated which
is designated as the East Stream] location (Fig 10) At a point
just south of that (East Stream^ polluted water in the streambed
was flowing at a low rate This was measured at the SE weir
location and which had a high conductance also Flowrates varied
between 6 and 23 gpm and specific conductances were over 350
pmhos This low water table condition flowrate is the baseflow from
the eastern side of the landfill and indicates a southeasterly flow
direction from it
Streamflow commenced in tne northern part of the stream 21
October 1931 and the north dam oegan to f i l l Stream specific
65
conductances were low indicating a clean water source Tnis
continued until 17 November 1981 when the dam overflowed ana flow
throughout the east stream began A weir was placed at the Rose
Hill Road NW location and was compared to flowrates at the SE
location Flowrates decreased and specific conductances increased
between these two locations
To further investigate the condition of a lower flowrate
downstream than upstream an intermediate weir was placed at the E
weir location (Fig 9) This snowed tnat the stream from the M
weir to the E weir was losing water to the aauifer (influent
condition) and gaining water at the SE weir (effluent condition)
The condition of a net loss of water between the NW and SE weirs
remained until 19 December 1981 when a snowmelt rain condition
caused increased surface runoff and a net increase in flow at the SE
location Upon analyzing the March and April 1982 streamflow
conditions the expected case of a net ground-water pickup from the
E to SE weir continued The explanation for tne initial net loss of
ground-water is the fact that the leakance from the upstream section
was being discharged into aauifer storage to raise the ground-water
table to an eduilibrium level Upon reaching a high recharge
equilibrium steady state condition any additional input will
eventually be transmitted as baseflow out of the landfill and a
downstream net pickup will occur A hign water table condition
prevailed during the January through May period maintaining this
condition In April the north dam broke through reducing the head
in that area by 4-6 feet The 9 April 1982 monitoring revealed that
66
an influent condition remained between the NW and E weirs but at a
reduced rate The 21 April lower stream flow condition shows a
small pickup of water between the NW and E weirs indicating the nigh
water table and low stream flow conaitions combined with the absence
of the dam had changed the conditions to an effluent condition
This was evident in the May monitoring period
Evidence of contamination on both the western and eastern sides
of the landfill supports the existence of a ground-water divide in
the landfill The west stream which drains the excavated area to
the west of Rose Hill Road shows contamination pickup between its
northern section and the SW weir The W well and ooservation hole
indicate high contamination levels which reinforces the concept of a
contaminant outflow to tne west excavation stream
As shown previously flow towara the eastern side of the
landfill is evident from the nign specific conductances and specific
conductances increases in the stream This is especially evident
during low flow conditions when the stream starts at a point to the
east of the landfill and flows with high specific conductance levels
From the literature a relationship between specific conductance
and dissolved solids exists the dissolved solids (mg1) are
approximately equal to the specific conductance times a factor
ranging between 55 and 09 (39) in this case it is taken as
065 (41) The dissolved solids increase coupled with the stream
flow increases provides a basis of calculating the dissolved solids
outflow to tne stream This calculation method was used in a
previous study (26)
67
The relationship
=Cinout Coutflow Qoutflow - Cupstream Qupstream Qinput
where the numerator is the streamflow pickup and the C- and
Q-jnput is the concentration and flow input from the ground-water
This can be used to estimate dilution level outflows from the
landfill Initially this is used for the ambient ground-water
pickup between the E weir and the SE weir This entire flow doesnt
come from tne lanafill but much of it is conaucted in the high
transmissivity area between the lanafill and stream from upstream
leaxage ana surficial recharge Tnis is evident when this section
of the flow pattern is analyzed on Fig 22 Therefore the landfill
outflow is mixed with tne ambient groundwater flow which dilutes the
landfill leachate before it enters the stream To illustrate-this
concept a calculation using the 9 December 1981 monitoring is used
At this time a flow of 672 gpm occurred at the SE weir with a
specific conductance increase of 7 ymhos between the E and SE
weirs The dissolved solids increase would be approximately 795
Today in tne stream
Where
Co = 90 jumho at SE weir
Qo = 672 gpm at SE weir
Cus = 83 jumho at E weir
Qus = 606 gpm at E weir
Qinput = 66 gpm gain
Cinput = 154 jumho
68
The 154 jumho value represents the contaminant level in the
ground-water adjacent to the landfill
This relationship is applied to approximate the concentration
level dilution in the ambient ground-water between the landfill and
stream The aforementioned relationsnip is in turn applied to the
landfill outflow into the ambient ground-water flow adjacent to the
landfill The ground-water receives landfill leachate dilutes it
and then transmits it to the stream The previously calculated
value of 129 gpm was used as the outflow from the landfill
Co 154 jumho flows into stream
Qo = 67 gpm flow into stream
Cus = 83 jumho background level
Qus = 67 gpm - 129 gpm = 541 gpm
Qinput = 129 gpm from landfill
Cinput = 451 jumhos
Approximately tne same contaminant levels from the landfill (tbl
umho) are arrived at as existed in the summer streamflow conditions
when the upgradient ground-water flow adjacent to the landfill was
at a minimum
In addition to using specific conductance to define
contamination zones electrical resistivity can be used to indicate
contaminated areas The measured earth resistivity is inversely
proportional to the conductivity of ground-water Water containing
contaminants with high ionic concentrations are more electrically
conductive and will have lower resistivity values than surrounding
natural ground water Therefore resistivity methods can be used to
69
delineate plumes of contaminated ground-water that have hign
specific conductances This has been demonstrated by several
investigations (11122328374045)
In this study a Schlumberger vertical electrical sounding R-l
was made in an area of known contamination at the W well (Fig 12)
Given the geologic constraints provided by the well boring log a 4
layer computer model was used to match field survey values A
Schlumberger sounding R-2 in an uncontaminated area north of the
landfill in the same geologic setting was used to provide a
comparison background sounding (Fig 12) A seismic survey N-4 was
made to obtain water table depth and depth to bedrock as input
parameters to a four layer resistivity model (Fig 8) Tne results
of the electrical soundings have been tabulated in Table 6 and
plotted in Fig 27 and 28 respectively
The ascending portion of the field Schlumberger curves were
initially matched using a two-layer ascending type master curve to
provide an approximate depth and apparent resistivity of the
overburdened topsoil layer (8) Tne second unsaturated layers
apparent resistivity was determined by using the graphical
interpretation of total transverse resistance The total transverse
resistance is approximately eoual to the peak value of the curve
times the corresponding Ab2 distance it occurred at This in turn
is eaual to the sum of the first two layers apparent resistivity
times their corresponding layer depths
70
bullH
OJ bull bullH 4J CO CM
c ce G bullrH
j-gt ca c c a 3 ltu O L
co CO 0
bullo Q bull laquos c n 3 -U OrH f~ 3 bO ltn y CO O cc CO ^mdashN
QQ bull
bO bOJJ C C Ci_i
O l T i O O O O O O O O O O O O O O O O bullH bullH mdash^ bullo 0 C c3 f| 3 O raquo O CO CQ
CO
rH
CO O
L 4J
^ltU
i- 1 ^n ^b O 4-) bull2 CM bullH C OJ 1 -U bullH CO C L O a ^-^ 0) a
rH c a L CD ltu (1) 3 tlt bO cO I
3 a 0) a Q 4J laquoa e CO 3 (H bO c C O bullH
CO TJ C 3 bull
bull O bO -i-3
0 CO C O3- O G O O O O O O O O O O O O O O O O O O ft rt1 -raquo - t l S^ ft tfigt f I mdash^ K_ l_ raquo mdash I gt fgt I l 1
(1) 0 rH CO CJ JD o^^ CO CO CQH lts
71
Legend
A actual field measurement
-e- interpretat ion
10000 bull
6000 bull 5000
4000-
3000shy
pound2000| ltD
_ r 1000
09
5 600 pound 500 - 400
I 300 a a lt 200
100 10
Fig 27
20 30 4050 100
Distance AB2
Schlumberger Sounding
200
feet
R-1
400 600
72
loooot
6000 5000 4000
3000+
laquo2000 e
r 1000
raquo 600 pound 600 ~ 400
$ 300 a a lt 200
100
Legend
A actual field measurement
-Qmdashinterpretation
10 20 30 40 50 100 200 400 600 Distance AB2 feet
Fig 28 Schlumberger Sounding R-2
73
Formula T = f
Background Sounding (9000)(15) = (3110j (1 7) + gt2(8)
= 16214 n- ft
W Wel l Sounding (b200)(60) = (500) (2) + pound2(28)
= 13250 SL- ft
To determine a resistivityp3 value for the third layer a
graphical interpretation for the longitudinal conductance S was
used(48) This is eaual to the sum of each individual layers depth
divided by their apparent resistivity
Formula S = -r1 +~r-raquobull-ra
Background Sounding 0017 = yyg + ~^
= IbOU - ft
W Well Sounding 0285 raquo -ggg 7^3 J~
= 179 v-ft
These values were input to a program which calculates a
schlumberger sounding curve (47) The theoretical sounding curves
approximately match the field curve as viewed on fig 27 and fig
28 To provide a check on the apparent resistivity of the saturated
layer at the W well the following relationship was applied 1OOOO
= spec-jfic conductance (umhos)
74
At the W well the specific conductance was measured to be 3 00
jmhos at approximately 10degC
Assuming a formation factor of 45 for the glacial outwash (23)
material Archies law is applied to estimate an apparent resistivity
of the third layer (7)
fgt FF x p
A= 45 x 103-n-ft
A= 4G3 JL-ft
This is a reasonable approximation to tne 3i= 179^-ft calculated
analytically from the sounding curve interpretation
75
Remedial Measures
With the analysis of f low patterns and contamination zones
recommendations to minimize the environmental impact of the leachate
can be reviewed The basic technique is to minimize all sources of
water reaching the refuse so that leacnate production is minimized
The oiversion of precipitation by a relatively impermeable cover and
proper channeling of runoff would minimize percolation into landfill
material Caps and seals can be constructed of clays fly ash
soils soil-cement lime stabilized soil memorane liners
bituminous concrete and asphalttar materials (15) Proper
contouring and grading will help minimize infiltration If a soil
cover is used a vegetative cover can be planted which will utilize
some of the infiltrating flow through evapotranspiration losses
during the growing season By minimizing the length of slopes and
providing proper drainage channels tne surface runoff can be
conveyed to a downgradient area outside the recharge zone
Therefore this surface water will not increase leachate production
from the landfill Also by increasing the slope of the cover over
the landfill itself a higher percentage of runoff and lower
infiltration will occur
To minimize upgradient ground-water influx to the landfill an
impermeable subsurface barrier or intercepting trench could be
used Barriers can be made of bentonite slurry-trench cutoff walls
grout curtains or sheet piling cutoff wal ls extending to the bedrocic
or an impervious layer to effectively prevent water passage or
create a head loss that wil l lower the water table In addition an
76
intercepting trench which has a perforated drain at tne lowest part
of the water seepage zone could be used to intercept and divert the
entire flow
These possibilities have been evaluated with the help of the
model to determine workable solutions for this landfill The
primary concern is to eliminate leachate flows to domestic wells
Initially a simulation was run that eliminated recharge over tne
landfill area (Fig 29) This had a considerable effect on the
ground-water flow patterns of the landfill area The mounding that
had previously occurred under normal recharge conditions was
eliminated and a general drop in the water taole within the landfill
of 2-3 ft occurred The effect of eliminating recnarge over the
landfill when the upper stream is running would cause greater
infiltration from the stream as evidenced by only a 2 ft head loss
in the landfills flow conditions This is evident when comparing
Fig 29 with Fig 24 Tnis indicates that this measure would only
marginally reduce the resultant leachate flow from the landfill
material that lies below the water table In another situation
where there is not such a strong potential for upgradient flow this
measure has proven quite effective (6) In this case the landfill
cover consisted of four layers an intermediate sand and gravel
cover immediately above tne regraded waste materials a 4 inch sana
bed designed to protect the overlying membrane a ilO mil flexible
PVC membrane and an 18 inch final cover of sand and gravel
77
Legend
landfill limit -raquo- -^ -raquobull excava t ion x-^x- s t ream
400 copy WNWNEECSESC monitoring well locations
= -= unimproved road fee t
Fig 29 No Recharge over Landfill
78
Controls such as 10-30 mil polyvinyl chloride covers favor the
development of an anaerobic environment which increases waste
decomposition time and would necessitate installation of gas vents
at several locations on the landfill cover Tne integrity of tne
synthetic cap may be further threatened by subsidence which create
differential stresses on liners Settlement would create areas for
ponding and depression storage and eventually necessitate regrading
the landfill surface The landfills south-central area has oeen
filled within the last year and will prooably need to be regraded
due to settlement within the next few years
Another possibility for a liner would be a soil-bentonite
cover A layered cover consisting of natural materials with low
permeabilities such as bentonite clay followed by a layer of highly
permeable material such as sand and finally a layer of topsoil can
be used Due to potential drying out and cracking of the clay liner
a synthetic liner is the preferred method
The most immediate technique is to grade contour and vegetate
the landfill cover which has been done at this site Althougn an
impermeable cover would probaoly reduce the amount of leachate
produced it would not eliminate the upgradient flow and provide
guaranteed protection of wells in the vicinity of the landfills
northwestern section
A slurry trench along the northwestern perimeter of the landfill
would effectively cutoff upgradient infiltration and divert recharge
infiltration in a southeasterly direction thus removing possible
leachate outflows from the radius of influence of the neighooring
79
wells This has been simulated using the computer moael ana flow
patterns as shown in Fig 30 Contour lines are distorted in the
vicinity of the slurry trench due to the 200 ft nodal spacing
Transmissivity values of 1 ftday were input at the slurry
locations to simulate an impermeable barrier Tne surface recharge
at those nodes does not infiltrate the relatively impermeable grid
nodes at the slurry locations and flows to the edge of the noae
thus creating a dramatic head loss within a short spacing To
effectively simulate this a variable grid spacing should be used
with reduced node grid spacing at trench locations to eliminate
distortion The computer simulation shows that the slurry trench
could direct flow in the landfill area in a southeasterly direction
and away from endangered wells In addition it would reduce
upgradient infiltration from the stream into the landfill This
measure would prevent leachate from spreading beyond this carrier to
possibly contaminate neighboring wells
The combination of both the slurry wall and impermeable cover
would be ideal measures to minimize generation of leachate and to
stop its spread to neighboring wells The slurry wall without
recharge over it or the landfill is simulated in Fig 31 This
indicates a lower water table tnan eliminating the recharge to the
landfill The slurry wall has blocked upgradient ground-water flow
at its location to the landfill
80
Legend
landfill limit -laquo- j -laquobull excava t ion ^^- stream
copy WNWNEECSESC monitoring well locations
= = = unimproved road ssi slurry wall
f e e t
Fig 30 Slurry Wall
81
Legend
landfill limit j- j- J- excavat ion x-v^gt- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road s==s slurry wall
400
feet
Fig 31 Slurry Wall without Recharge Over It or Landfill
82
An intercepting drainage trench is considered next If a trench
was excavated to a 30 ft depth in the outwash material extensive
shoring would be required In addition difficulties would arise
when the trench was excavated below the waterline Tne trench would
be sloped to provide drainage and backfilled with a highly pervious
material to intercept and divert leacnate locally a conouit which
is perforated on the top to allow infiltration and unperforated on
its lower perimeter to permit continuous drainage to the collection
treatment center would be installed on the bottom of the graded
trench The difficulties involved in excavating below the water
table ano shoring the sidewalls to permit implacement of a drainage
conduit at a 30 foot depth make this option increasingly infeasible
83
Conclusions and Recommendations
The location of the South Kingstown landfill in permeable sand
and gravel glacial outwash material (107 ftday) combined with the
high hydraulic gradient across the landfill area (20 ft1600 ft)
creates a high potential for ground-water contamination to occur
This is intensified because refuse nas been placed below the water
table The low hydraulic conductivity of the compacted refuse (1
ftday) and the excavated area to the west of Rose Hill Road have
both contributed to modifying the original southeasterly flow
pattern These modifications have created a ground-water divide in
the landfill at approximately the western third section Tnis
results in approximately 13 of the leachate flow from the landfill
or 63 gpm flowing in a southwesterly direction and 23 or 129
gpm flows in a southeasterly direction Infiltration from
precipitation recnarge over the landfill (up to 9Upound) and from tne
upgradient stream during low water-table periods provides tne
necessary influx into the landfill Evidence of contamination is
clearly seen on both the east and west sides of the landfill which
reinforces the previously stated flow patterns
Of the several remedial measures reviewed the contouring and
grading of the landfill topcover and drainage swale provides the
most immediate protection The topcover has been graded mulched
and seeded to provide a low runoff slope generally to the east
The drainage swale on the left side of the landfill has improperly
graded sections which should be corrected Its northern section
could be drained into the northern sections swale and the southern
84
section drained to the southeastern section of the landfill Tne
point of the drainage swale which divides the northern drainage
swale from the southern one should be determined by a field survey
Cost is a major contributing factor when determining which
remedial measure is to be applied to the given situation For the
purpose of this report cost estimates are not presented but rather
the effectiveness and feasibility of the remedial measures are tne
primary considerations As was reviewed and simulated in the
computer models the slurry trench and impermeable cover over the
landfill are two viable options that would effectively provide
protection to the domestic supply wells in tne vicinity The
impermeable cover would eliminate precipitation recharge into tne
landfill yet drop the water table only a few feet due to upgradient
infiltration from the stream This would decrease the hydraulic
gradient thus diminishing the potential for a contaminant outflow to
surrounding wells The supply well of primary concern is one to the
west of Rose Hi l l Road marked well D on Fig 2 If contamination
occurs in this well the most effective measure would be to block
off leachate flow in this direction by installing a bentonite slurry
trench at the location indicated previously This would effectively
prevent leachate flow in the westerly direction and diverts it to a
more southeasterly direction In addition the slurry trench
precludes infiltration flow into the landfill from the upgradient
stream
85
Tnis report has effectively reviewed tne original ana existing
flow conditions and contaminant levels in the vicinity of the Rose
Hill landfill The purpose was to provide an understanding of
ground-water contamination patterns and study possiole remedial
measures
86lt
Appendix A
Precipitation Records
Monthly normal precipitation 1941 -197O
i$l Total monthly precipitation
KINGSTON RI
14
ia
^JO T I bullbullL
pound 111 laquobull
4
a
n
-
^
-
-
KS1JAN
^Ii R3 HB MAR
1
1 APR MAY
1
1 JUN
1981
JUL
-bullraquolaquo H
AUO SEP
K3~~f$s bull
_imdash
i1S 1
OCf NOV OtC
171 1 iI1
JAN HB MAR APR MAY
198
Fig 32 Precipitation Record
- - - -
IM 1 MtvJrflgtlgt c ortli-A t lUN I r nraquo rl - -
gt|MO CLIMATOLOQICAL OUSERV ATIONshyr-r bull JK gt raquo - 1
i5fWA I VAPOR Al IOH -bull AIM If MPCRATUM bullF 0 riccipn AT ION UNO IlMf
bull 14 H 14 H mdash Vshy ADDITIONAL DATA IfUAlUS OATt 1 bull raquof bull bull 1 ta
14 Hw rlaquo4 w bullbull bull 1 114 1mdash4 (llrl 1 1 1fl Hll
0 kmdash
Mraquo M4 raquo i T i 4 bullraquo-laquobull i i
Lgt f 1 21 S 1 Hbull - - bullbull -
ltJL 1 2 01 - - _ _ 1
mdash
-
1 12 _ Q I
mdash shy
mdash 4 (C ( - - fVi 1 - 0
1 (1
^ 1
Vvraquolaquo IJ1^ raquo CP O 3L 1 Z - i bull j-t-J
1 J
LH Vb T n 0
1 gt fl oo O ~l 2 L - bull 1 P )laquo jn iP IP - OOI L5L mdash shy
-t 84 ^(^^ ^fi P i flja 0 JO II 10 tl tcgt 7 J IV wllaquo
h l2L bull 0 lt -_ shy
-id VJ lt 3C 2 ft OOL -mdash
U 71 C1 Sr 2 13 2 nl JLJraquopound HP r M ltf1- (
IMe 2 ii O It
n jlt dl 1 1 bull o o-il ST i 1 i 25 2-x-1
-
ri
i tlL O mdash gtbull bullgtlt 1ft -o- is Oil So iJK 2-io otv u 31 fil loi 2 il Oll it Of wr is i1raquo -iZ 1 deg|0 01
M IT So - mdash
- 13 1 CT mdash i - mdash 21
shy
Tl Ci av ZUll IMT 0 IM Pe v _ 1) T) S) ii3( dlt Ii 2 lt^2 II li- S1 riivi To 7HX lt3lO 14 ^2- iTi I li 011 -- - -i -^IS no 5^ or i | T Jift laquoV OoH bullla It Va iCO mdash L OIL 11 bullvf poundgtpound lS_ flv oh P-lfe 1 poif _ shy11 IB kl (4 itlaquoT lamp llt0 oot^
mdash -n
It T1 |ir( L1 HI 2 0 oil
U 1M ft go C ICf^ -^2 Z laquo-|o
11 it 5 bulln - TO o abull Li u-i IT1 -- Iw O ltM (I bullbull bdquo-I(K 1mdash -tilltLlA ttfe
i Dgt ac -- U 44 4 11 1 1- ytd i i_i J-K 0 i if -i i i V t Wl raquoOHM 1-1 US D C P A R T M f N T OF COMMfRCE t 4 1 IUII 1 1 ^~) mdash
llaquo- Hi NC bull bullh bull bullJL^V HBl CO 00
11
)jLsVyr^gturv
^ | TKu
|-_t_ bull(
IIMgt I I Mt|UU III- II 11
PNECIPITATIOH
I 1 1 IMX
IMO
bull llfclaquo I UCIUKI) Ur C V A r U M A AHO CLIMATOUOCICAL OBitH
E V A F O R A T I C r i Jttffl laquo amp hMIlaquoJllaquoJIIlaquoBgt
DATE AOOITIOMAL DAIAKMAKk M
bullraquobullmdashlaquo
tp 01 (1 Of Ll OOI ooo
0^1 o-i 10 tl |00 102
OC (1 13 Ofl
it i rc DS os an
(1 SV o
Ul 010
(ISl 101 I on
130
II 5= Otl
ss lt 001 (IK Ml
jt il HIT
7 it
ow Wo 17 Top 2-01 OIO
(0 oov zi oot
u CO ^A 0 to Zoi CLflS
bull50 01 ljtj
nshy 5H LO OIt
50121 IVO QJO
14 Co Ho LO Hl ^pound Jl 1
ltM ool fllc
H Tl 01 II
11 11 Q1
iH OIO
HO 2 llaquol 11 II
lifc
IV-IIM ul OIPAITHINT or COHMIICC NOAA
NAtlOHAL gtIATnlaquoll raquotraquoVlClaquo CD
r~
All TCUMMATUNI ^V UII rgt ITmi 1 Cwphu Obic i gtn t ngir-H 30
rilCiriTATIOH
JJ T I rTJ-rimdashr-iramj|MP CLmATOLOQ
laquolaquo jftilCiii bullIHO
Oi1l ADOITIOHAL DAIAlllu
Ilf4ft
Sii1
(1 2 IO OO
Hl ii SO
us OIM
Q^L
a A3 Hi SZ Sf^ bull 12J2
HI Z-SF OOl 1C t HM IA H ICP fiJA
OOl 10 (310 sn 310
if HI (0 ^01
bullit SO 28H poundJ1 11 006
14 35 TX oon II (bull2 it zr II c-S
rr Zll lo 31 OP an 31 a 31 oor
CSW O-ll Si CC Of 011
Oll _ I |ft
00
u i oerraquolaquoTMiMr of c NOAA
NATIONAL K C A T N C M SCMVlCC
TC^S lk)oiVroTJA
TETT I 7X
1raquolaquolaquo 4 bdquo ir lt er ni I^OV ltqgl j--^ TQ
MICiriTAllOH ITIND
D|mdash
b5NO ctiUATOtoiCAL oeit^
OATI AOOITIOMAL OATAVlHAtt
0-tt
Mlaquoh bullbullbull- rshy laquo
I- ltltriu HI I 4 bulllaquobullbull1
Zii
30 Dfellt otvt
at HA
OOI
62
iJ_S2 HI if
bull- 20 SI 2i So
So
VVfr
OSfc
I (
Jtlt
3aoi
r j -bull ie MA
Irill iiol
in^ 14
Mo
Zll
214
21 1P
00-i
bulliron
17
bullr
11 i ir- I J Ktf^c
US D E P A R T M E N T OF COuMEDCC I | C gt A A
K AIlaquo Ttupf lATuit r
|SlVi AlJ PIICIPITATION
oJud (El
VIM i Uraquo
MIND E
EVAPORATIOH flnrft bull A ftufiifccdll
KECORO OF eVAPllHAtlil bull I CLIHATOLOOCAL OBSERVA ^Hij
14 MM A_M AOOIIIONAL DATA11 MAIM
Mr bullH Oo|
M Si lift
bull221 IHI
ZS Ji 40 IZV
icr KS I
HZ 111
bullT 21
loA UK JA IP
v^ ft
1M 2Sshy IT Tl
71 V |
i I 31 1deg a
uty^ U bull3
ons 1 CiO TxX
HHO (10
3H 19 12 10 IP
raquo3H raquo | 5t io
OP OIT
14
vO UI Of PANTMINI Or COMMCRCf MM O A A
F ngt TIHH
iiicffwiffc 4 rJ (TIM bull Cempltit Obitittiio
AIlaquo TIMHIATUM PHICinTATION I V A f OK ATlPrl
OATI ADDITIONAL DATA KMAlIt
U4laquo4 +
03H Ji
10
rc a 1 16 oi ii
tiiy 10
OI
II i23 or o 13 -y~ou HO
II 3V III i 3 t
V laquop oot
OM1 SS ne
T an -i IP
Olt zr LTV
3T 001
a -11 2T
10 an 31
-1 raquo 131 UP 3H lf 14 Lpoundshy
it 14 30
IS
Ui O I P A K T M f H T OP COWlf ICfM O A A
NATJONAI V C A T M C n f t K M V l C K
bullbullbullbullbullshy -2 o AIlaquo TIMMRATUM f fKICIPITATIOH
OATI poundt- MMINMAL DATAk
ZP 51 lo icr
011 111
OoT IHf
Ut 003 am
3o 13 ao
4A X 05shy
H4 i IjJyiV131 ooc js
IH oi 01 tL 18 13 a
No 11-7
rivgtp OO| M Hi 03 01
It 12
bull I 41 bull7119 14 ^^ raquo 31 15 lampk n M ho i
Jo -j-
-J
I
Ml H^ I _
amp2ampUi^= LS 0 S 0-f bullTTT
-Vmdash gt U_ bull 1 rOHM I- 11 OI OCPARTMlNT OF COMM(NCC
HO NATIONAL W f A T M f H ftfraquoVlCI
98
Appendix B
Boring Logs
99
X iHECT 1 ff 2
OAT American Drilling amp Bor ini I Co Inc
wo WATH smn EAST PR ov IDENC E ft 1 Town of South Kingstown South K ngstown R I MOLENO X-J
TC 100 RCSS bull ujrMonitorinq Well Installation | South Kinqjtown R I UNC a STA Pf KXICCTHJ LOC ATK3N
bull cfrserrr TO above S MPLES S FNTTO _ _ |laquolaquor A-109 SURF ELEV RE PORTSEr
GROUND WATER O6SE RVATC MS 1 CDREraquolaquo m-T nn75 laquo A 256 - 20 mdash Hew y
Instolled 32ofT-l2 PV C - JO- COMPUTE 111275 K toia 3- I-WI 1-38 TOTAL MRS bdquo10 screen BORING FCACUAM J K lanq MAI rraquo HomnwWI 300 140 IampPCCrc Mamlaquor Fall 24 30 lampaaiona SOLS ENGR
LOCATION OF BORING H ONITOKING WELL
Coung Samplt Tjp Blow per 6 Manure SOU IDENTIFICATION Strata SAMPLE ^^^yV Bloot
foot
Otptni
From- To
el
l
on Sampler
0-6 1 -6-13 12-18
Dentity or
Conmt j
Chang Remark include colo^ graaation Type of tod lie Rao-coMr type condition nordshynetiDntotf time leamt and tie No Pen Rtlt
2 No top sample 5 12
1 loamy fine sand
bull)^ 40 30 36
5- 616 0 23 20 16
noist iense
Brown fine to coarse SAND some fine to coarse gravel Trace silt
^
1 18 18
36 8-0shy57 40 30 V 35
|0-||-6 D 14 24 20 Srown medium to coarse SAND Some fine gravel cobbles
7 IRshy 16
27 75 37 3
IS- I- D 5 14 16 3bull
ISshy 15
42 50 I9--0shy50 65 20-2ll-6 D 9 23 26 bull Jrown fine to coarse SAND Tbullwshy 1Z 75 90
22-0 Trace silt trace fine gravel
124 120 74 60 52 41
7S-ltlaquoil-A DX 71 16 13 wet very dense
Gray-brown fine to coarse SANC Some fine to coarse gravel little silt
H IR u
40 30--0
3C-30-IO
3l4-334
334-3314
38 4-434
D
c
C
C
7 IflO
94 6
we tr j
y se
ft irox
30MOshy
31 -4shy
Gray-brown fine to coarse SAND Trace silt
Gray-brown fine SAND some lilt trace fine gravel
Too of Rock 31 -4shy
Gray-pink GRANITE
6 7
amp
CJ
IltJ A
60
601
IQ mdash
2(
4
5 i Hard
ft 5ome seams bull
GROUND SURFACE TO J 4 U3CD_ ^JVrf bullbull( tutu t to 4o 4 SampM Type Proportion UMd MOB Wtx 3 OfaM on 2OD Sampler SUMMARY-
OOry CCartd WltWen4 Hoc OlolO Canmonieraquoi Don any CoKeem CarMWncy Earm Barrlaquoj 11 14
UPgtUnOigtturod Piuon trite (Oto20dego 0-Kgt Loei it 0-4 Sait 3O+Hofd Rock Corng 14 Kgt-30 laquo4 0 rte 4-8 MSHM Samplet TPTtitPit Ai Auger Vvanefett tarn 2Olo39 3O-M Owlt n laquo-lS Strlf rinit nn v 1
UTiUndlshffbed ThrMOll and bull 33to9O 5O Very 0laquo nraquoe 19-30 V-3trraquof - | OLE NO X-l
TOVH rim - iA it raquotoraquo
100
SHEET 2 o_L
WO WATEt STUET [AST ft OVIDENC pound a i American Drilling amp Bor ing Co Inc
MCLl WQ X- 1 Tt AOORCSS i
LIME A STA KXICCTMJ tuf same as 1 | tame as i LOCATION
W PORTSEf mo OB nj urt eflaquo T
illtPLES S
P
CVTTO nlaquo mun orv
^s f^ Tin i GRCVMO WATER OBSERVATONS CASING SAMPLER CORE BAR
START Typi COMPUTE tome at 1 same aiH
TOTAL MRS BORIMG FOR CMAN n bull IT INSPECTOR SOILS EMM
LOCATION OF BORING u HfVJTneTfi UFI _
8
Counf Blo-t
foot
Dtpllo
From To
0( on SampMr
0-6 f 6-IZ
Moittir
Oonuty or
Contilt
Strata Ctnngc
SOIL OCNTiriCATION Rtmorkt ineHifl cotot grqdotion Typlaquo of Mil etc Roo-axtrPlaquo condition Mrdshynlaquot Drog tun ttomt end tic
SAMPLE
No Ptfl RfK
434-4o4 c
approx 7 minj
per toot 454
Gray pink GRANITE Hard Fairly solid core
lt_4 24
Bottom of Boring 45 -4
-
~
bull 1
GROUND Sorrow Tye
SURHCZ 10
bull OiOry CgtCord WWothod UPUnditiurMd Piston TPlaquoTtraquotPtt AtAuotr VVor
UTltUndinrvd TTMMO bull bulltat
iivnPilaquo(onioni Uraquot4
me OioiOItttt laquoraquo20
wmt Z0ie33
and 361090
c M
C1 5 Si
-SOshy
ASING
IOtgtWtigt bullnlot Dn 10 Loci M Mod 04 SO Dm 1shy Viry 0laquo
s _
TMEN 0 hMl on 200 SoiTBUr laquoity ConcMMt Conorawncy gtbull 0-4 Sort 30shym 4-B MStlfl M BH9 Strtf bull ts-so v-swt bull
t-HOrt Ear Bern RoetCorrt
i ^^^^^ bull
-[MOLE no x-i
101
raquoMEC rAmerican Drilling amp Bor in g Co Inc 1 ofj_ DATE wo WATlaquo smn UST Plaquo IOIDCNC j laquo i
Town of South Kingstown South Kingstown 8 MOLE MO Jlt Z TC rx MCS3
rtprr uAurMonitorina Well Initollation | South KinqitowrxRI UNC A STA P KATIOM ME POCT ^rwT TO above I OFFSZT
uD^r laquorlaquorTTO 6 -109 suw tLEv Sgt louffJOCNO
0 tj Tlmlaquo WOUND WATER 06SCRVATC US gtW Rsdl SING SAM^EH CORE BAH
26 ^_ 12 $TAlaquoT UL 2Z2i Ji r TTP NW ltA sr IJZC Z5 CCOMPLETE
SitLO 3 I-3B- 1-38 TOTAL MAS 41 BOAINO FOACMAN JK1 ana nf ni n MonwwWl 300^ 140 BIT bullK^CT
gttonvrar Foil J^laquo 30mdash Diamond SOOJIEMGM
IE HFII
iCaunq SampM Trplaquo BMMtpw6 UOIIIK- SOIL DCMTIFKATION Siraia SAUPLE Blow DlaquoPIAraquo of on SompMr HtmorU mcJuo cotes gradation Type of Dwuily
pw or CXang writK Roel-eolorlyp condition tvort-From- To Vfoot 0-6 f 6-2 12-18 Coniitt egt rwtiOnAngtimt wamaondtte No Praquon Rtlt
2 Brown fine SAND little silt 2 2-0shy5 15 18 moist Browi fin to coarse SAND 18 5- 6-6 0 14 25 27 vlaquo Troc fin aravel | 25 wy Ifl 11
dlt tns 35 40 38 moist n in-il-i Lgt U 15 18 ie is li1 Irl IS 31 I2-0
~~43 1
A) Jrown coars to medium SAI MD 48 moist Little fine to coarse gravel
|5-IA-Xlaquo 14 47 41 fn D laquo y Little silt rrqa coarse sane 3 18 I1
68 In IS 44 32 34
n ^n-^i-A- w 2o 19 29 wet 4 la -59 lens ltfO no
25-0 2amp bulllaquo- 77 c BOULDER r[ 4 i
27-0 5X ~W 24 24 bullWar- 5 Ifl irown tine to coarse SAND some
dens 29-0- Fine-coars gravel trace silt
30-3I oxx 30 32 30 moist irown -gray fine SANDiom e 6 l rr Vlaquoy 31 -0 silt trace fine oroveTILL
Bottom of Boring 31 -ampbull shyBent casing -pulled out and moved over 4 - washed amp tJrovlaquo casing to 30 -Installed 3C gtof 1-12- PVC - 10 screen
WOUND SUraquoraquofCE TO 3pound 1 yijfD MW t ASIMC TMCJ laquo olaquorod -bor of borina
SomoU T]Fplaquo ProigtuliOraquoH UMd MIOtgtWLx3Orolt lon2OASanlaquoMr SUUMARY-D=Dry CCorad Wlaquoworaquonraquod bullact OiaiO CanM gnMM Daonty CIMIH Caamraquoci EffW 8or^ 2pt
UPiUnairurMd Pition Itnt laquoM2O O- O UKraquolaquo 0-4 Soft 3O-hHard Roelaquo Corrig o- JO M0mlaquo 4-8 MSNff SOTipM 1 p^ 3O-9O OwgtM bull-IS Slid
TPlaquoTraquojraquoPit AAugtr ViVon mini tamt 20to39 UTtundiifir6d TrwMOtf and JSloSO 50-raquobull Vary 0nlaquo [HOLE NO x-2 B-3O V-3Mf lev rim - IAIT raquosectlaquoraquo
102
300 iu 24
1 UMnii ffi 140 laquo 30
CA1INC tf
gt taWCTf
bull 0gtlaquo i R Cook Jr_ R Millineton1 Wttn
I~
1 VAMtl CtMG
1 W HO-t MO
1 Oraquo 1 laquo0~ twt
L 1 laquo-raquo VfcM^lf [wlaquoraquoCI ^ ^ K3Ot III laquo
0-LS D
5-65 D
LlQ 10-115 D
15-16 Tgt
Lraquo 70-51 n
25-26 D
F
I O-O Ci
A Allstate Drill ins Co vi o i
PROVIDING R 1bull raquoraquo uvraquonn~ N M O M I T O P I N G HE1 _^lt -^ PI-Traquo UJU
CUM Town of South Kineraquotown raquoraquo 1 1TA maoer Propolaquolaquod Sit for Slude Disposal nltn
laquo V-449 iampAAtut i a 138 ort STI bull r 42777 CtOuMO IKVtllON
Cill bdquo 258 DA II MN ru 42777 rilaquolaquodO laquoraquoTti rum 1911
AU1TATI
MMUI1 raquolaquogtlaquolaquo laquoKiO itXHHKraquoriOi of sous MUAHI nMTKlion Ot CMlaquoMC|kOraquort tl CO~VH DXltgt raquomlaquo laquotf IMi COIOI C4l II I 1raquo gtlaquo^ Oraquo 1Ol rC t Xgttgt VtfKOe Craquo Mi 1 ft liMraquoK laquo0^tlaquot nfgt
1-2-1 10 TOP SOIL FINE LIGHT BROWN SAND traclaquo of ilt
16-31-17
22-24-21 100 FINE TO MEDIUM LIGHT GRAY SAND trace of fine gravlaquol and raquopoundLt
lfl-37-34 150 LIGHT BROWN FINE TO MEDIUM SAND little poundinlaquo gravel
21-17-15 200 MEDIUM TO COARSE SAND bullomc fine gravel
12-4-10
265
Observation well installed
NOTE No casing blows taktn
bullbull B-23 ow
^w^ 265 I raquo bull raquolaquo bull I W
11 laquot gtbullraquo Vlaquo 14 W gt_ c-shyji bull alaquo bull jraquo VI laquoHshyw bullbull m raquobullbull D-6 raquo Mshy
bull bull laquo Vshy
1
bull bull
I
103
MAMMII Allstate Drilling Co ulaquorr 1 or 1 FftOVIOCKZ H L traquolS mTArm^S MONITOR NR WEL
VNO wr3JJO__raquoraquou_24__ HCU MO P-74 n iu riBwi Town of Slt7H^ Xirpin
mdash^ laquo0J P 1 1 bull ^n^ciit^o TVlaquow^laquott1 bullraquoit wt 140 nu 30 olaquor fBu lkv Waste Disposal Arcai
MUTAH a V-449 R Cook Jr UMlaquoiigti D 1 38 0t| raquoIJ raquo 5277 rlaquo SUMO luvlaquorv-laquow
mdash 5277 fipe -raquoT pfpm 150
H MCIO IMNTlXAflON Of SOU t(kAIlaquoS rrn 0-laquoraquo
5 -SF 01 w in laquobull -raquo ^ lit
D 1-2-2 TOP SOIL V-1-oraquo
15 IPbull FINE TO MEDIUM LIGHT GRAY SAND AND GRAVEL
5-65 D 37-27-35 some silt
10-11 D 20-14-18
15-165 D i 17-14-14 155
BROWN COARSE TO MEDIUM SAND little fine to coarse gravel trace of silt
20-211 D 4-4-2
230 GRAY BROWN VERY FINE SAND
25-26J D 7-8-9 AND SILT 265 fvarvedl
Observation well installed
NOTE No casing blows taken
wta 10 n uuraquo c^imdashbull IgtM laquolaquobull- B-24 ow ~ 14 ltfc laquoraquobull vlaquo^ M laquobull r O 0 fmtt bull W-L 26 5
-0- CgtCmdashgt bull laquolaquobull mdash laquo 1 - raquoraquo 1 gt 1laquo bull 1 gtraquor to bull mdashbull bull bull bulllaquo I t l~laquo 1lt Uraquo mdashbull ) bull 1 gtbull ft 0~ H laquoy bullM ta bull -IN la laquobull OPUM bull($ IMI
mdash H raquo laquo-bull
104
Appendix C
Calibration of Specific Conductance Meters
105
Specific conductance measurements were made using a beckman RB
338 temperature compensating meter and a YSI rtooel 33 salinity
conductivity temperature meter The YSI meter is not
temperature correcting A formula to compensate for temperature
differences to standardize YSI measurements was used (21)
A long probe for the Beckman meter was used to measure conductivity
in the wells Differences in conductivity between the YSI ana
Beckman meters and the Beckman short and long probes exist These
were calibrated in the laboratory using 001 N and 01 N KC1
solutions Values presented are Beckman short probe values The
Beckman long probe values were reduced by 76 and tne YSI values
were multiplied by 11 to adjust to Beckman short probe values The
YSI meter was used in the latter phases of the study for the
stream contamination due to the greater accuracy of the dial readout
scale
Table 7 Specific Conductance Meter Calibration Table
Concentration (KCL) 0001N 001N
Specific Beckman short 145 143 143 1247 1245 12GO
Conductances Beckman long 190 191 188 1639 1650 1665
umhocm 9 25 C YSI 132 131 128 1131 1140 1150
average values Beckman shortBeckman long = 075
Beckman shortYSI = 11
106
Appendix D
Computer program Flow Chart
107
F1g 33 Computer Program Flow Chart-
1TpoundR MAP TCO
NEWPER
WEWSTP CZAX
HEWIT TRANS TCOF ROW COLUMN
Yes
Yes
108 The following is a description of the USGS two-dimensional computer
program Iterative Digital Model for Aquifer Evaluation updated
December 1972 by P C Trescott The program written in Fortran
consists of a MAIN program and six subprograms or subroutines which
themselves are organized into subprogram sections The subroutines and
their sections are listed below
MAIN Program
DATAIN (subroutine) COEF ITER (section) CLAY MAP TRANS NEWPER TCOF
ETRATE COMPUT STORAG
NEWSTP LEAKAG NEWIT1 NEWITO CHECK ROW CWRITE COLUMN STEADY PRNTA OUTPUT DRY BLOCK DATA
The program begins in the MAIN program which controls the sequence
of passage to the subroutines Sequential steps are described in the
program as shown in the flow chart of Fig 32 Emphasis is placed on the
steady state confined aquifer case as applied in this study First data
input is read in the DATAIN subroutine This data includes transmissivities
or permeabilities starting heads storage coefficients and grid spacings
Nodal transmissivity values are then computed for the water-table problem
in the TRANS section (COEF subroutine) This procedure is necessary here
because the subsequent routine for computing iteration parameters (ITER)
keys on nodal transmissivity values which would not have been input to
the water-table problem In the water-table option these would have been
109
computed from given bedrock and water-table elevations to obtain the
saturated thickness component of the transmissivity calculation In this
study water-table option was not used and the transmissivity values were
input directly The program then passes to the ITER section (DATAIN
subroutine) to compute the iteration parameters which expediate or even
cause convergence Next the MAP section (DATAIN subroutine) is utilized
to initialize data for an alphanumeric map if this was requested in the
input options Transmissivities are then computed for the confined
(artesian) aquifer case (water table not specified with input options)
in the TCOF section (COEF subroutine) These coefficients are harmonic
mean values of adjacent nodal transmissivities weighted by grid sizes
Time parameters and pumping data for a new pumping period are then read
in the NEWPER section (DATAIN subroutine) followed by entry into the
NEWSTP section (COMPUT subroutine) which calculates the size of the
time step Leakage coefficients (hydraulic conductivity of the confining
bed divided by confining bed thickness) are next computed in the CLAY
section (COEF subroutine) if leakage was specified in the input data
which was used in this study
A new iteration is then initiated in sections NEWITO (COMPUT
subroutine) NEWITO saves the current head values and compares them to
the updated head values for determining closure This is followed by
nodal transmissivity values being computed for the water table or water-
table artesian conversion problem Transmissivity coefficients are then
computed for the water-table problem in TCOF (COEF subroutine) Total
head values are then computed with the alternating direction implicit
procedure using the Thomas algorithim first along rows in the ROW section
110 and then along columns in the COLUMN section both in the COMPUT subroutine
Then if a solution is not obtained (because the error criteria for
closure is not satisfied) the MAIN program branches back to NEWIT1 subshy
sequent sections TRANS TCOF ROW and COLUMN repeatedly until a
solution at the particular time step is achieved NEWIT1 increments the
iteration counter and is immediately followed by NEWITO The program then
moves to the STEADY section of the COMPUT subroutine to check if the
closure criteria for steady state has been satisfied Output is then
printed in the OUTPUT section of COMPUT if steady state has been reached
or if the particular time step is designated for output
The program then branches back to NEWSTP (COMPUT subroutine) and
moves through the subsequent routines until the last time step in the
pumping period is reached Output is then promoted in the DRY section
of COMPUT if specified in input data If the last pumping period in
the problem has not been reached the program branches back to the
NEWPER section and moves again through subsequent sections otherwise
the program will terminate or start a new problem if one follows
This study was simulated as a steady state problem which can be
simulated by setting the storage coefficient of the aquifer and the
specific storage of the confining bed to zero and using one time step
of any length
111
Appendix E
Computer Data Sheets
RGSEA
10 ROSE HILL LANDFILL MODEL 20 30 40 LEAKAGE 50 60 70 CHECK 80 90 100 HEAD 110 120 1 23 IQ 100 5 001 37E-OU 0 130 100 001 0 0 1 4 0 - 1 - 1 1 - 1 - 1 i i i i i i 1
ISO 1 10 0 1547E-05 01 10 1 1 160 04642 200 200 1 1 i it
1QO 190
CARDS I THROUGH 19 - CODING SHEET
CHEAD
100 110 120 130 131 132 140 141 142 150 151 152 160 161 162 163 164 165 170 171 172 173 174 175 176 177 178 179 1BO 101 190 191 192
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 539
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 58
25
25
25
25
25
25 621
25
25
25
25
25 662
25 25
25
CARD SET 2 - STARTING HEAD MATRIX (FT)
193 194 IVb 196 197 190 200 201 202 210 211 212 220 221 222 223 bull 224 225 230 231 232 233 234 235 236 237 23B 239 240 241 250 251 252 253 254 255
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 23 25 25 25 25 25
25 25 - 25 25 25 25 25 25 25 25 25- 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 - 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25
25 25
25
25 25
25 25
25 25
25
25 25
25
25 25
25
25
25
25 25
25 25
25
25 25
25 25
25 25
25
25
25 25
25
25 25
CARD SET 2 - STARTING HEAD MATRIX (FT) - continued
STORC 1512 FRI 19 FEB 82
100 110 -1 -1 - 1 - 1 0 0 120 130 140 ISO 160 170 100 190 200 210 220 230 240 230 251 260 261 262 263 270 271
CARD SET 3 - STORAGE COEFFICENT
LEAK
100 110 120 02 130 _ 18 02
I ltu 18140 025 150 02015015015 19 deg25
02 160 022 bull-laquo- J1 5 j 1 z laquo- l^
170 015 180 016 laquo02
190 016 OE025
200 02504019022021025 2 5 i S lt03 0252i2 n
230 030 deg23 deg2 deg2 deg2 -02023023 240 022 250 022025025 02
027043 013025
30() 025025025 310 025031 320 024025
CARD SET 5 - AREA OF STEAMBEDAREA OF NODE
120
Appendix F
Bibliography
121 BIBLIOGRAPHY
1 Agpar MA and 0 Langmuir Ground-Water Pollution Potential of a Landfill Above tne Water Table Groundwater V 9 No 6 1971 pp 76-96
2 Allen William B Hahn GW and RA Brackley Availability of Ground Water Upper Pawcatuck River Basin Rhode Island USGS US Government Printing-office GS 66-624 19bb
3 Annual Book of ASTM Standards Part 31 Open Channel Flow Measurement of Water and Waste Water by Weirs D 2034-68 1975
4 Annual Book of ASTM Standards Part 19 Infiltration Rate of Soils in Field Using Double-Ring Infiltrameters D 3385-75 1975
5 Baeaecner MJ and W BacK Hyarogeological Processes and Chemical Reactions of a Landfill Ground Water V 17 no 5 1979 pp 429-437
6 Beck WW Dunn AL and Grover H Emrich Leachate Quality Improvements After Top Sealing1 8th SHwRD MERL Symposium 1982
7 Beckman WK Transient Modeling For Estimating Sustained Aauifer Yield master thesis presented to the University of Rhode Island Kingston RI 1978
8 Bhattacharya PK and HP Patra Direct Current Geoelectric Sounding Elsevier Publishing Co New York 1968 135 p
9 Bouwer H Ground Water Hydrology McGraw-Hill Book Co New Yoric 1978 p 378
10 Braids 0 Cocozza pound Fenn D Isbister J Rous P and B Yarc Procedures Manual for Ground Water Monitoring at Solid Waste Disposal Facilities Environmental Protection Agency530SW-611 Cincinnati Ohio 1977
11 Cartwright K and MR McComas Geophysical Surveys in the Vicinity of Sanitary Landfills in Northeastern Illinois Groundwater V 6 no 5 1968 pp 23-30
12 Cartwright K and Fd Sherman Jr Electrical Earth Resistivity Surveying in Landfill Investigations Reprinted from Proceedings of ohe lOtn Annual Engineering and Soils Engineering Symposium Moscow Idaho 1972
122 13 Clark TP Survey of Ground-Water Protection Methods for
Illinois Landfills Groundwater V 13 no 4 1975 pp 321-331
14 Dunne T and LB Leapold Water in Environmental Planning WH Freeman and Company San Francisco 1978
15 Faro DG Upgrading Hazardous Waste Disposal Sites Remedial Approaches US Environmental Protection Agency500SW-677 Cincinnati Onio 1978
16 Fenn DG Hanley KJ and TV Degeare Use of the Water Balance Method for Predicting Leachate Generation From Solia Waste Disposal Sites US Environmental Protection Agency530SW-lfa8 Cincinnati Ohio 1975
17 Geisser 0 An Electric Analog and Digital Computer Model of the Chipuxet Ground Water^ Aquifer Kingston Rhode Island master thesis presented to the University of Rhode Island Kingston RI 1975
18 Hahn GW Groundwater Map of the Narragansett Pier Quadrangle Rhode Island Rhode Island Water Resources Coordinating Board GWM 5 1959
19 Hemsley William T Koster C Wallace Remedial Technique of Controlling and Treating Low Volume Leachate Discharge USEPA National Conference on Management of Uncontrolled Hazardous Waste Sites Oct 1980
20 Hughes GM RA Landon and RN Farvolden Hydrogeology of Solid Waste Disposal Sites in Northeastern Illinois Final Report to US Environmental Protection Agency PUD SW-l^d Cincinnati Ohio 1971
21 Keller GV and FC Frischknecht Electrical Methods in Geophysical Prospecting Pergamon Press New YorK NY 19bb
22 Kelly WE West Kingston Landfill An Evaluation of Its Effect on Ground-Water Quality Rnoae Island Water Resources Board Water Information Series Report 1975
23 Kelly WE Geoelectric Sounding for Delineating Ground-Water Contamination Groundwater V 14 No 1 1976 pp fa-10
24 Kelly WE Ground-Water Pollution Near a Landfill ASCE Environmental Engineering Division Journal V 10 No EE6 Dec 19b pp nay-nyy
25 Kelly WE personal communication January 1982
123
26 Kelly WE and OW Urish A Study of the Effects of Salt Storage Practices on Surface ana Ground Water Quality in Rhode Island NTIS FHWA-RI-RD-8001 1981 54 p
27 Kimmel GE and OC Braids Leachate Plumes in a Highly Permeable Aauifer Groundwater y 12 no 6 1974 pp 388-393
28 Klefstaa G Senalein LVA ana RC Palmauist Limitations of the Electrical Resistivity Method in Landfill Investigations Groundwater V 13 No 5 1975 pp 418-427
29 Landon RA Application of Hydrogeology to the Selection of Refuse Disposal Sites Groundwater V 7 no b 19b9 pp 9-13
30 Lang SM Bierschenk WH ana WB Allen 1960 Hyaraulic Characteristics of Glacial Outwash in Rhode Island Rhode Islana Water Resources Coordinating Board Bulletin No 3
31 LeGrand HE Patterns of Contaminated Zones of Water in the Ground Water Resources Research v 1 No 1 1965
32 Palmauist R and L Sendlein The Configuration of Contamination Enclaves from Refuse Disposal Sites on Floodplains Grouna Water v 13 no 2 1975 pp 167-181
33 Pinder GF A Digital Model for Aauifer Evaluation Techniaues of Water Resources Investigations of the US Geological Survey Bk 7 Cl 1970
34 Purushattam D Tamxe GR and CM Stoffel Leachate Production at Sanitary Landfill Sites ASCE Environmental Engineering Division Journal V 103 no EE 6 Dec1977 pp 981-988
35 Remson I Fungaroli AA ana AW Lawrence Water Movement in an Unsaturated Sanitary Landfill ASCE Sanitary Engineering Division Journal v 94 no SA2 April1968 pp 307-316
36 Rosenshien JS Gouthier JB and WB Allen Hydrologic Characteristics and Sustained Yield of Principal Ground-Water Units Potowamut-Wickford Area Rhoae Island USGS US Government Printing Office GS 67-324 1968
37 Roux PH and B Vincent Electrical Resistivity Evaluations At Solid Waste Disposal Facilities US Environmental Protection Agency SW-729 Cincinnati Ohio 1978
124
38 Salvato JA Wi lk ie WG and BE Mead Sanitary Landfill Leaching Prevention and Control Water Pollution Control Federation Journal v 43 no 10 Oct 1971 pp 2084-2100
39 Sawyer CN and PL McCarty Chemistry for Environmental Engineering McGraw Hill 1978
40 Stellar RL and P Roux Earth Resist ivi ty Surveys - A Method for Defining Ground-Water Contamination Ground Water v 13 no 2 1975 pp 145-150
41 Todd OK Ground Water Hydrology John Wi ley and Sons Inc New York 1959
42 Tolman AL Ballestero AP Beck WW and GH Emrich Guidance Mannual For Minimizing Pollution From Waste Disposal Sites US Environmental Protection Agency-500SW-677 Cincinnati Ohio 1978
43 Trescott PC Iterative Digital Model for Aauifer Evaluation US Geological Survey Open file report 1972
44 University of Rhode Island Academic Computer Center CalComp Contouring Manual
45 Warner DL Preliminary Field Studies Using Earth Resistivity Measurements for Delineating Zones of Contaminated Ground Water Groundwater v 7 1969 pp 9-16
46 White EF A Report to the Town of S Kingstown Utility Survey Engineering Corp 1967
47 Zohdy AAR A Computer Program for the Calculation of Schlumberger Sounding Curves Over Horizontally Layered Media Using the Method of Convolution US Geological Survey Denver
48 Zohdy AAR Eaton GP and DR Mabey Application of Surface Geophysics to Ground-Water Investigations Technidues of Water-Resources Investigations of the US Geological Survey Book 2 Chapter 01 Washington US Government Printing Office 2401-02543 1974
3
peoy ||H asoa
X ltbull
Alt
f c c
o
^ ^ o o f a
O OJ 83X1
o O
x o
seepage observation -t West
hole Landfill Area
Legend mdash landfill limit bull j--excavation limit r^-s stream copy WNWNEECSeuroSCSEN
monitoring well locations = = = unimproved road
A contaminated domesti supply well
D uncontaminated domestic supply well
feet
Fig 3 Supply Well Locations
5
a 03
N lo ^ gt
laquo c 2
mdash w
3
X o ^
3 O L
o CO
0 opound E bullo
0
co
c
o0
uj ^
0 o o c
o $ bullA
E c o
w
bullo t_hraquo9 O
_OplusmnJ ca
u
pro
ve I 51 H
bullo 0gt
UJ _c e poundbullo Mzbull w gt 0
laquorege cc
0gt -^^ o a5 raquobull bullo o sect 3 mdash laquoo o wcz _
3Ogt c $c o_ X
aw e 05 0 (0 3 bullo
o a 2 2 u
hydraulic properties and the subsurface geometry enable estimates of
ground-water outflow to be made Streamflow measurements were used
to verify these outflows Contamination levels using specific
conductance measurements as an indicator were measured in wells
streams and observation holes to help delineate the extent ana
degree of contamination An electrical resistivity sounding was
conducted in a known contamination zone
The primary objective of tnis study is to determine flow
patterns in the vicinity of the landfill ana recommend possible
actions to contain or minimize the impact of the contamination In
oraer to fully evaluate these goals the aforementioned parameters
were input to a computer model to produce simulated flow patterns
under different conditions The simulated present conditions were
matched with field water table and stream flow measurements to
calibrate the model A series of simulations were then run to
evaluate flow conditions before the excavations anaor landfill
existed Remedial measures such as reducing recharge to the
landfill and implementing a slurry wall to blocx off leachate flow
to endangered wells were simulated to evaluate their effectiveness
Based on this analysis recommendations are made as to how to
minimize leachate production ano best alleviate the immediate danger
of the contaminant plume spreading to unpolluted domestic supply
wells
background
The South Kingstown landfill is in a geologic setting that is
very similiar to the nearby West Kingston landfill This is located
about 3 miles west of the South Kingstown landfill and has been
studied to assess leachate effects on groundwater quality using
specific conductance as an indicator of contamination levels
(222ltt) Both sites were located in abandoned gravel Quarries which
were filled in with refuse to create the landfill
In the literature numerous authors have shown that the character
of contaminant plumes from landfills are largely dependent on the
local geology and geohydrology A study on Long Island (27) in
similiar glacial material illustrates that the Quantity of flow is
dependent on the hydraulic conductivity of tne aauifer the
hydraulic gradient and the vertical cross-sectional area of the
aauifer it flows through This is expressed as Darcys Law (41)
Q = KIA
wnere Q = flow quantity
I = hydraulic gradient
K = hydraulic conductivity of the aauifer
A = vertical cross sectional area of the flow area
Specific conductance was used as a contaminant tracer to show that
the plume from the landfill flowed downgradient and vertically
through the full thickness of the aauifer A study in Iowa (32)
indicates that the size ana shape of the contamination outflow from
a l a n d f i l l can be predicted from existing geohydrologic conditions
and that the horizontal shape of the outflow extends downgradient
8
from the source and parallel to ground-water flow lines Other
parameters which control the extent of the contaminant plume are
dilution and dispersion in the aquifer and the adsorption properties
of the aauifer material (31)
The amount of leachate generated depends largely on the amount
of water that infiltrates through the landfill to increase tne water
content of the refuse in the landfill The precipitation recharge
that percolates down through the unsaturated zone to the water table
moves in a vertical direction (35) Surface runoff soil moisture
storage losses and evapotranspiration account for tne precipitation
that is not transmitted tnrough the unsaturated zone of aeration
(3315) Upon reaching the saturated zone the water enters the
ground-water flow system Ground-water mounding has been reported
in landfills due to the decreased hydraulic conductivity of
compacted refuse relative to surrounding aauifer material (20)
Chemical processes within the landfill leachate outflow and
surrounding soil cation exchange capacity relative to water duality
of the surrounding aduifer have been studied in Pennsylvania (1) anu
in Delaware (5) A procedures manual for ground-water monitoring at
solid waste disposal facilities was developed by the US
Environmental Protection Agency (USEPA) (9)
Several reports have been written that investigate site
selection design criteria and remedial measures to correct
leachate problems (29) A survey of ground-water protection methods
for landfills in Illinois studies relationships to the water table
theory of liner installation and monitoring devices (13) Sanitary
Landfi11-Leaching Prevention and Control presents a review of
preventative methods such as means to minimize infiltration
interception of ground-water and other pollution control measures
(2 37) A study in Pennsylvania on actual measures implemented to
collect and treat a landfills leachate discharge presents a site
specific study (19) Leachate Quality Improvements After Top
Sealing1 shows that by minimizing infiltration at a landfill in
Connecticut the outflow leachate water quality can be improved
dramatically and contamination plume reduced significantly (6) The
most comprehensive reports on remedial approaches to upgrading waste
disposal sites and ground-water protection methods have been
compiled under USEPA contract (1542)
To assist in evaluating remedial measures the US Geological
Survey (USGS) computer model Iterative Digital Model for Aduifer
Evaluation was used It was originally developed as a model for
simulating two-dimensional aauifer problems (33) It had been
updated since its original development to accomodate different
options (43) This model has been applied to glacial outwash
regions in Rhode Island (717)
10
Description of Study Area
A map of tne landfill area (Fig Z) was obtained from tne town
of South Kingstown The excavation to the west of Rose Hill Roaa
the landfill area directly to the east and the presently operating
area to the east of the central stream comprise tne overall study
area This study will concentrate on the west landfill area whicn
has recently reached capacity and been closed to further dumping
This site received mixed refuse for the past 15 years The depth of
the excavation where the landfill presently exists was approximately
to bedrock in some places Tne exact depths of landfill material is
unknown
The landfill cover has been graded and sloped generally eastward
to convey surface runoff to the eastern side A sandy soil that was
excavated locally was used as tne cover material The northern
section has a vegetation cover and the recently filled southern
section has been seeded and mulched The six monitoring wells W
NW NE EC SE SC were placed by the town of South Kingstown to
provide water quality information
Referring to Fig 2 the west excavation stream drains the area
created by the excavation to the west of Rose Hill Road and flows
throughout the year The central stream drains a small watershed
area which lies to the northwest of the landfill and drys up during
part of the year These streams flow into the Saugatucket River
which flows throughout the year and is larger than the west and
central streams combined
11
The USGS Groundwater Map (18) was initially consulted to proviae
information on the ground-water flow patterns (Fig 5) and the
geology of tne area (Fig 6) The surficial geology borings and the
vertical geologic cross-section at the base of the study area
indicate shallow water table and bedrocic and a nearly constant
saturated thickness (18) Boring logs at the W well ana a point
approximately 150 feet south of it indicate glacial outwasn material
which is primarily sana with a trace of gravel over bedrock at a
depth of approximately 33 feet Borings at the east landfill area N
and S monitoring wells indicate the same aquifer material
(Appendix B)
The ground-water map developed by Hahn is taken as
representative of conditions existing prior to the excavation of the
I l andfill (18) This indicates water-table contour lines that run in i
a general northeasterly direction This means tnat flow was
originally in a southeasterly direction However contamination of
domestic supply wells on the west side of Rose Hill Road has
occurred (Fig 3) strongly suggesting that the original flow pattern
has been altered by the excavation to the west of Rose Hill Road and
the landfill to the east of it Domestic supply wells were formerly
located directly to the west of Rose Hill Road but were aoandoned
when they became contaminated from landfill leachate New wells
were located to the south and west away from the contaminant plume
of tne landfill In addition a well located at the northeastern
corner of the landfill was contaminated and a replacement located to
the east of Us former location on tne opposite side of the central
12
Legend scale 124000
mdash-40 mdashground-water contour elevation
Fig 5 Ground-Water Map
13
Legend feet
TILL
Fig 6 Geology Background Map
14
stream This second wel 1 also became contaminated Domestic supply
wells located near tne northwestern corner of tne landfill and
approximately 300 feet south of it nave remained uncontaminated
These well locations serve as an indication of tne extent of the
landfill contamination which is largely dependent on the groundwater
flow patterns To furtner investigate this problem and provide
substantial information on which to base the geohydrologic analysis
field studies of the area were conducted
15
Field Studies ana Procedures
A map of the lanafill and an aerial pnotograph of the area were
obtained A tracing of these maps superimposed upon another
delineates stream landfill and monitor well locations (Fig 2)
The field investigation concentrated on the west landfill area ana
its aajoining streams ana monitor wells The east landfill area and
the three monitor wells in that area are induced in the latter
phase of the study in oraer to expand the model area
A traverse which establishea tne monitor well elevations was run
using a Carl Zeiss level These were originally sitea in by the
town of South Kingstown using a local USGS reference datum number 40
(18) The wells of known elevations then served as benchmarks for
referencing adjacent stream elevations This in combination with
the depth to water table measurements at each well enables tne
water-table surface geometry of the area to oe visualized
Water-table measurements of the west landfills wells were recordea
over a ten month period to record fluctuations (Fig 7 Table 1)
The east landfill areas wells were monitored for a five month
period Using a given water-table condition a ground-water map was
developea of the area (Fig 4) This indicates an outflow from
the landfill primarily in a southeasterly direction and partially
in a southwesterly direction
Additional bedrock and water-table information was ootainea by a
seismic refraction survey at several locations along the landfill
perimeter A Bison Model lb70C Signal Enhancement Seismograpn was
used to maxe the surveys Lines were run (to a length of kOO feet)
16
17
w s p bdquo S bdquo s S S a laquolaquo _
s 2 8
V
r bdquo
3 s a
-R s
S
S 3
t
raquobullraquo
S
5
K
r
~
3
K
pound
7
S
bdquo3
C 5 S
shy raquo S s
1 3 s 3 2 5 ^ bull
5 m
s o
^ 3
raquo
--
R bull 5
s pound J O s
5 a 3 7 3 m
5 s a ^
iraquo a s rlaquo
M ^
^ c o 2 5 s 3 a S R
rd 3 y a O =J
^ bdquo
JJ s s 3 bull ~ I
~ s 5 3 a s a
(Ogt (U
2
-t =
r s s in
5 y
a s
5
3
s
5 a
^ a
3 a 51 a bullbull
sj 5 Ml
3 a bull
s raquo
a
0)
0
^ mdash
a j -
-3
C
g S
S
bull a
-
~ 3 o
2 s s 3 a bdquo s s $ Al s
(1) = $ s 3
S
c a a
3 e 5 s N s S a - 3 = s s a 5
a s s - 3 S shy
4
0
a s
bdquo tfH
bdquo
3 a
bdquo
s a
e bullfl s i s s a s a
3 nt
s s 3
g laquo s3 a
~ J s 2 a s o s S s 3 a a j laquo s o s
3 bull laquobull
2 a 7 3 a 3 a ^2
s mdash 5i o
bull bull
mdash
3 o
ss a
fc mdash
3 1-sect m ishy n
18
in both directions to provide a check and permit accurate estimates
of the depth to bedrockThe seismic results allow approximate
interpretations of the depth to the water table and bedrocK thus
permitting an estimation of the saturated thickness Ground
elevations at the location of the seismic surveys were determined
from a topographical map and field siting From this information
water table ana bedrock elevations estimates were made Bedrock
contours are listed in Fig 8 In addition a table which
summarizes the seismic refraction results for the unsaturated
saturated and bedrock layers velocities and depths at each survey
location is presented in Table 2
Scream gauging stations were established on the two streams
bordering the west landfill (Fig 9) Three stations were placed on
the central stream These provide information on the influent or
effluent condition of ground-water flow in the upper sections of the
stream and ground-water baseflow from an area adjacent to the
landfill into the stream (Table 3)
The stream gauging stations used were 90deg V-notch weirs The
weirs located in the SE and SW positions were placed in the
streamoea with a liner of plastic upstream to minimize underflow
The weirs located in the NW and E positions were cut to fit in
recesses of concrete culvert pipes Concrete plywooa interfaces
were coated with roofing cement to minimize bypass flow Upstream
water pressure and a snug fit hold the plywood sections in place
All weirs were implaceo according to AigtTM reouirements and flowrates
calculated using the standard 90deg V-notch formula (3)
19
N
seepage West observat ion Landfill hole
Area
Legend landfill limit excavat ion limit
copyWNWNEECSESC monitoring well locations
= = = unimproved road -- WNES-number
seismic refraction locations
-40shy approximate bedrock contpur elevation
feet
Fig8 Seismte Survey Location
20
c ^-^ c4j ^laquoc in -=r 3shyjj bull pn f- 4-gt bull in in OjJ bull bull a jo bull bull O JJ
co CM o on on CO CM CTNVO VO co CM o on on Q gt_x rH oj on a oj on a - rH oner
rmdash on sr i i
M z Z
gt gt gt
X-N CO laquomdashv CO CO bull igt gt bull
1 gt fc^gtgt bullbull ^ ^ ^
C 4-gt O t igt O J- 4J O H m o o o 3 bullH CO O rH in 3 bullH co vo o in 3 ~ 1 i-k -i ^trade fj rj ui ij o CO o n o rH =r co o n vo vo vo co o bullv O O O
O raquo On-3 rH O -bull- rH ON in _ IH in oj - rH bull rH VO OrH bull rH On ON pH d)u CO -UCO 4J OJ CO 4-gt gt
C mdashbull gt CM gt CM H-l O CO
v- ^^ N C 0
bull0 N CO
4-5 -0 _c^gt in in CO CO
C x~ c -^ t-oo in i 4J j_gt 41 4J bull 9 bull bull 4J bull
o j ON O O 3 (0 O4J O ON ON QJJ t~-^3- OJ 4-gt L
CO CM trade CO CM rH rH OJ co CM oj on Q ^ _ CO 3~Q-- n 45 Q mdash OJ OJ OJ C (0
1 11 3 nZ 2CO
gti gt gt CO CO CO ^-x m -s CO
rH rH ^ ro^^ bull gt bull ^ igt gt bullgt gtgt bull r O -Q 4Ji JJ O 5- JJ O pound- ^ O 4) oj o on (0 CO
3 bullH CJ O O in 3 bullH CO Cmdash VO on 3 pound-laquo H CO o n in inco co o n ma- r co g^ 5sect^ o
o rH on oj O bull- rH ONCO L O_ rH OJ VO M
rH bull rH =t rH bull - OJ T CO CO M CO 4-gt rH CO -U rH CO 4-) s
uits
CO 4-gt 4-5 T3 gt CM gt CM gt CM cc CO CO CO
3 3gt oa tlp^ CO O CM O gt 4J O 40 i 3 r+ k C pound JS
CO pound
^^ s -bullgt cmdash on poundZ VO CTI trx 4J 4J 4J
) bull bull bull Q Q Q Q4J 3shyc O-JJ CTgt OJ OJ Q-IJ inco on CO CO CO o co CM oj on co CM oj on co CM on
Q Q QON^ Q bullH Q^
rH rH 4J rH
O bullraquo L Z bull CO CO CO
i gtgt rH oj on gt tgtshyCM ^ cO^-s CO ~ CO
CO CO J X fc^_ bull^gt bullgtgt bull gt gtgt bull gt CO
j_ jJ O pound- Jj -P O Li deg =fObullH co on f- ^ 3bullH CO CO O in 3bullH CO
g^ -^2
poundsect HO
eis
mic
3 CO in in in in in in co o n co o n
o -^ r oj in O rHCO CO rH bullrH bull rH =T OrH bull rH OJ f-CO 4J bull- CO 4J rH O0) J-)
gt CM gt CM gt CM 4J
CO N_^ m^
bull OJ
t t poundshyCO CO CO CO rH J3 gt r-t oj on gt r-i oj on gt gt r n o j o n
lto co lto CO T bull ii-4 laquomdash bullmdashH
bullo CO L L 0)
CM CO cc
21
N
545-594
seepage observation
hole West Landfill
0NE I47-509
Area
Weir 45
i487-531
0 EC Al3-467
Legend bullmdash landfill limit -bull---excavation limit r-s stream
copy WNWNEECSESCSEN monitoring well locations
= = = unimproved road
Weir location and elevation
feet
Fig 9 Weir Locations and Wate r Level Ranges
22
JT NO
S shy S
O
bull ry m
oa
NO
(M raquo 1 03 or NO m
JT O O raquo
O NO 03 (j
PW tn in ^4 fraquo
m CN) f O O (M Oj
mdashraquo 3 M
s cshy -raquoraquo
o in in ^
rjO
laquobull NO ON
o bull-lt ^
H fy (NJ
tjgt
1 4 03 O
o
o
03 CM
in0
0
7 raquo
9gt
IM i iev NO
i in
i ru
i 0 rsi -or^
sO NO
CO O
03 raquo
1 O3
pound o ro CNJ
03
tn B OJ
o 03
m oi
NO
(M
r
(M
CO i M 03
m N ltn ~+ ltM -
QJrH
O M O ^ ^r-
oo m
8 a
m
^ NO
8 fNl
rshy03n
m - in
o laquoO
bull3 as m o 03 03 4
i O
i ^
shy
O
ltM bull^
ON f tn H 1 4 raquo4 i-4 H P-t
^^ lt-l
r-laquo
^ 1 1 1 1
pound raquoraquo O)t o gtz
bull bull ltbull
lt2
1 pound OJ
3 oi g bull
pound
1 pound laquolt bull
3 bull o a
pound
5 laquo15
f bull 3 Jl s
5bull 1 5
23
A field study to determine the infiltration capacity of a
section of tne landfill topcover was conaucted A modified version
of a double ring infiltrometer was used to study infiltration rates
(4) The cylinder diameters useo in this study were 8 inches and 18
inches A constant head of 6 in was maintained in the
infiltrometer and rates of infiltration were determined Tnese
results and an analysis of surface infiltration into the landfill
are included in tne analysis and discussion section
Specific conductance levels in the monitoring wells in the
streams bordering the landfill and at observation holes near the
landfill were measured (Fig 10) This is a good indication of the
mineralization of water (39) Specific conductances were measured
intermittently over the ten month period to develop a picture of the
extent and degree of contamination in the wells (Fig 11 Taole4j
and in the surface contamination monitoring locations (Fig 11
Table 5) A comparative standardization of the Beckman (short and
long probes) and YSI specific conductances is in Appendix C
A surface electrical sounding using the Schlumberger array was
conducted adjacent to Rose Hill Road at the R-l location (Fig 12)
in an attempt to delineate the vertical extent of the contamination
zone Well W was used as a centerpoint and a reference for
water-table depth pore water conductivity and depth to bedrock A
Schlumberger array electrical resistivity sounding was also
conducted in an uncontaminated area at tne R-2 location (Fig 12) to
provide a comparison background interpretation A seismic
refraction survey N-4 was conducted at the same location (Fig 8J to
24
N
excavat ion
Seepage West observat ion Landfill hole
Area
Stream 1 Seasonal observation 0 EC
hole
East Stream2
Legend sw Weir landfill limit j--1--^ excavation limit
copyWNWNEECSESC monitoring well locations
== unimproved road
feet
Fig 10 Surface Contamination Monitoring Locations
25
8000T
7000
O bull U) W6000
Legend
0 sc A NE O W
A SE O N W
a EC
1 O N D J F M M
Time months Flg11 Flucuatlon In Specific Conductance in Wells
26
Table 4 Specific Conductances in Wells (pmhoscm at 25degC)
West East Landfill Landfill
Date NW NE EG SE W SC N E S
81581 851 938 236 2356
102981 171 3268
11381 3268
111081 304 988 1100 258 3800
111481 426 2736 1216 186 4560
111781 304 3610 433 389 4560
121981 380 1406 129 103 380
1982 160 152
31582 274 760 1064 61 334 8000+ 182 53 84
52182 450 1500 1125 112 712 8000+ 175 255 150
52282 425 1320 1200 110 850 180 320 170
27
O
ct c r i c o o o o o c M o m o in CO CM unp^
3bull t- fmdash o^ co tmdash vo co in co cmdash co in a
bull bull1 1-1 trade4 rH rH^ CO 4)2
~ plusmn4J o O CM ^_
o n CO vO J oraquo 0C0M
cu rH rH rH rH rHin tmdash
3 iCM 4J
^j CO CO
E O0 ltU -H n o c E
See
pag
se
rva
t
rH O in 0 0 O O 0
O o x rH Cmdash
0 0n
cu rH mdash O tmdash X o o o o c o o o o r H r H i n o i n i n o O
bull L in oo co oo oo o cy cr o rH CM o cr ONc fcJ bullH on en m m rn c^n rH rH rH0 pound CO 3 CO
t CM0gt s o o o in rA n ^o oo in tmdash oo 0gt zr =r a- JT JT$_
T)C CO
~ E CO ^ _bdquo ltu CO g r H r n c n i n o o r H r H
vgtO ^D O ^^ ^O CO ^^ ^^ JJ 2 4) rH rHCO t
c CO
CO c 9) rH 0
CO -^ C c CO ltuo famp O trade t iH
0
bullo co n ^
oS
o ^^ bullH m
i co rn O CQ O1 CO CO 4) c2Q 3
CO
mdash^ bull cmdash CMin 1 gt rH vO vO O CTgt CO
s CTgt CO OO Ogt Craquo- tmdash cu O CO rH z 0
bull_bulllaquo
H bull L o in r in o oo in 3 rfy ff^ tir f^ CO C^~
4)bull
Z 3
^ ^ ^ ^ H r H r H r H r H rH r H C O r H C O a O C O a O a O C O C O r H i H r H CO OO - gt 0 0 ^ - gt ^ raquo - ^ ^ 1 - gt ~ gt - C O C O O O
U ^ raquo ^ - ~ raquo O ^ ^ O t ~ C O r H - r r ^ - ^ ^ JJ r H C M v O r H r H r H r H r H C M C M r H i n c r gt rH CO CM gt laquolaquo - - -^ bullmdash mdash bullraquoraquobullgt -v -v ^^
~ v O r H r H r H r H r H r H r H r H lt M C M C M CM O O r H r H r H r H r H r H r H r H r H r H r H r H rH
in rH cmdash
CO vo
CO vO
41 rH CO
CTgt rH raquo CM rH
cn CO
o 0 rn
CO cmdash
tmdash fshy
CM ao
iT rH
m
ogt ao
O o vO
CO t-
tmdash Cmdash
CM CO
rH CM
I
rH CT
O vO in
CTgt
in c^
CM ao
CM CM
in
-
bull
CO bO C bullH T3
cy ~
_
CJ E 3 ^ n c bullH
1-1
CO
^H
28
excavation
West Landfill
Area
Legend bullmdash landfill limit -bullbull--bullexcavation limit r~~s stream
copy WNWNEECSESCSEN monitoring well locations
= == unimproved road
electrical resistivity sounding
feet Fig12 Electrical Resistivity Sounding Location
L
29
allow estimates of depth to water table and bedrocic to be made
Soundings were carried out to 500 foot electrode spacings to insure
that hredrock was penetrated and to facilitate interpretation These
results and a discussion of the soundings interpretation are
included in the analysis and discussion section Schlumoerger
resistivity soundings were made using a Soiltest R-bO unit
30
Model Development
The USGS Iterative Digital Model for Aauifer Evaluation was
usea to develop steady state flow models of the study area (43) A
flow chart of the computer model and a brief explanation of the
subroutines usea is presented in Appendix D The stream locations
elevations and aauiferlandfil1 geometry and hydraulic properties
were input to the model to compute head values at each 200 foot
grid spacing node (Fig 13) The input data which is for the
existing excavation and landfill conditon is listed in Appendix E
The head values that are computed at each grid space are in turn
loaded into the CalComp plotting routine (44) where a grid spacing
is setup with the computed head values at each node The contouring
program linearly interpolates between these head values and
generates a contour map The computer simulated ground-water
contour map for the excavation and landfill is presented in Fig
14
The streams in the model generally serve as controlling boundary
conditions When using computer simulated geohydrologic models of
an area choosing the boundary conditions for the model that are the
same as prevailing conditions in the field is a critical step in
model development Extending the models boundaries to areas in the
field that have a minimum influx of ground-water across them
simplifies the proolem of calculating fluxes from outside the model
area The eastern boundary is bordered by glacial till which has a
low hydraulic conductivity estimated to be 67 ftday(2) This
contrasts to the high hydraulic conductivity of glacial outwash that
makes up the model area of approximately 107 ftday(3036j
31 N
o 9
bullO O
32
33
The Saugatucket River serves as the controlling boundary on the
east A small drainage area directly to the east of it provides a
minimal influx
Beyond the moaels northern boundary the glacial outwash valley
extends to the base of a till covered h i l l on the western half ana
on the eastern side extends along the Saugatucket stream Due to
the relatively large drainage area that lies upgradient from the
northern boundary a recharge flux eduivalent to 10 inyr over the
drainage area on the till hill and outwash area north of the model
area was input as underflow (Fig Ib) Part of this was input at
each northern boundary node Till has a lower infiltration capacity
than outwash so more of the precipitation w i l l be transmitted as
overland runoff resulting in a lower ground-water baseflow The 10
inyr of recharge that results in a ground-water inflow from the
combined till and outwash region represents an estimate that is
smaller than the 14 inyr recharge for glacial outwash areas in
Rhode Island (25)
The glacial outwash valley extends beyond the western boundary
No significant ground-water recharge flux was estimated at this
boundary A relatively low ground-water gradient exists to the west
of this which does not provide a significant flux across this
boundary Tne southern boundary is basically the outflow region for
the area and therefore would not reauire any ground-water flux into
the moael area across this boundary This boundary was set south of
the point that the streams in the model merge together Therefore
the streams which lie to the north of it are the controlling
34
scale 124000
Fig 15 Northern Drainage Area
35
boundary conditions The flux out of the downgradient outflow
region approximately eauals the influx from precipitation recharge
and boundary influxes
When tne stream configuration in the moael area are reviewed it
can be seen that they comprise a large portion of the boundary
area The screams can act as sources or sinks for water in the
model thus providing to and removing water from the aquifer The
leakance option was used in the model which provides for a confining
bed and aouifer area beneath the stream to be input
The leakance is defined as the hydraulic conductance of the
streambed divided by the streambed thickness which in this case is
taken as 1 foot The leakance value at each streambed node
restricts the flow between the aduifer and the stream The
streambed hydraulic conductivity is typically 01 the value of tne
hydraulic conductivity of the aduifer (717) The value 107
ftday was used for a streambed conductivity based on a value of
107 ftday for the aquifer The aduifer and stream hydraulic
inputoutput exchange at eacn node is calculated by initially
finding the difference between the initial field stream head
elevations and the computed head elevation values at the
corresponding nodes This head value is then multiplied by the
(Leakance value at each node) x (stream area of each node)
Therefore if the aduifer head was lower than the stream head the
stream would act as a source of water for the aquifer and vice
versa
36
Tne leaxance input at each stream node is the ratio of the
actual field streambed area in each node to the area of each node
which is 200 ft x 200 ft = 4 x 104 ft2 The west
excavations stream width is approximately 3 ft central 4 ft and
east 5 ft Therefore if tne west stream traverses the node
directly without meandering it presents a leakance of 3 ft x 200
ft4 x 104 ft = 015 Leakance and streamhead values were
input at each node to set up the stream flow parameters in the
models
A recharge value of 14 inyr over the entire area was input at
each node This represents a value of precipitation that is
transmuted into tne ground-water rather than being directly
evaporated evapotranspired through plants or overland flow
runoff The precipitation recharge flow from the stream into the
aauifer and boundary fluxes provide the model witn input flow
parameters
From analyzing the available information it was determined that
the study area lies within a glacial outwash area with a relatively
shallow bedrock The seismic survey around the landfill generally
indicates a depth to bedrock below the land surface of approximately
29-43 ft with corresponding saturated thicknesses of 19-33 ft as
seen in Table 2 This agrees with borings from tne USGS groundwater
map in the stuuy area (18j The seismic survey was run at a low
water table condition which was several feet below the high water
table level (Fig 9)
37
High water-table saturated thicknesses were used to develop
model parameters For the purpose of this model study the saturated
thickness was set at 30 ft except in the vicinity of well W where
there is a bedrock high (Fig 8) At this location a high water
table saturateo tnicxness of 8 ft was estimated In tne vicinity
the seismic survey was conducted the bedrock elevation at this
location is the highest and the saturated thickness the least Tnis
can be seen by an east-west cross section of tne landfill (Fig 16
The boring log for well W indicates a sand trace gravel outwash
material (Appendix B) Boring logs at the eastern landfill area N
and E indicate similar material On this basis the hydraulic
conductivity was estimated at 107 ftday (3036) Witn the
exception of the landfill and the bedrock hign areas the
transmissivity values were set at 107 ftday x 30 ft = 3210
fto day From the literature the hydraulic conductivity of the
landfill material was estimated at I ftday (19) The
transmissivity of the landfill material in tne nortnern section was
estimatea at 1 ftday x 30 ft = 30 ft^day or approximately two
orders of magnitude lower than the outwash In tne landfills
southern section the original excavation was not as deep as in the
northern parts The landfill material was estimated to makeup only
one half tne saturated depth the remainder being the original
glacial outwash material (Fig 17) Therefore the transmissivity
at the southern end was estimated at 15 ft x 107 ftday + lb ft x
1 ftday = 1620 ft^day These values were graded into the 30
ft^day values at the landfills northern halfway point These
38
were input as transmissivity values to the model at their respective
locations This model did not use the water taole option so
water-table fluctuations did not affect the transmissivities
39
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Model Calibration
A simulation was run using the initial estimates of stream
parameters aquifer and landfill hydraulic conductivities
transmissivities boundary and recharge conditions to approximate
water taole conditions in tne fiela Initially the existing
condition of the excavation area to tne west of Rose Hill Road and
the landfill to tne east were modeled in order to calibrate the
model to current field conditions as shown on Fig 4 The simulated
well values (Fig 14) fall within tne range of field values (Fig
9) The resulting contours also provide an approximate matcn This
can be seen by comparing Fig 4 with Fig 14 An additional check
was to match the flow loss and gain in the streams between tne weirs
in the central stream which w i l l be discussed later The
simulated flow value from the excavation drainage stream is the same
as that measured at the SW weir location Having calibrated the
model by approximately matching well water levels nead contours
and scream flow values different field conditions and possible
remedial measures can be simulated
When the model grid was laid out over the study area as viewed on
Fig 13 the stream configuration rarely traversed the grid nodes near
their central axis When the stream locations were input to the
computer the information was documented as crossing the central axis
of the grid nodes The result of this is a slight aberration when
the actual stream configuration is laid over the computer graphics
head contour output The streams dont always cross the groundshy
water contour at the logical location Rather than modifying the
actual stream configuration to adjust then to the computer output
their actual locations are presented
42
Simulations
i The primary focus of the computer modeling is to analyze flow
patterns under changing conaitions in the near vicinity of tne raquo
landfill The study areas overall flow patterns as they exist
today are first presented in order to realize the lateral east-west
head contour lines between the stream that directly borders the
landfill on the east side and the SaugatucKet stream (Fig 14)
This indicates a general southerly flow direction in that area As
different conditions are modeled these contours generally maintain
their east-west orientation In order to facilitate interpretation
of flow patterns in the near vicinity of the landfill flow patterns
to the west of the stream that borders the east side of the landfill
r are presented in the subseauent models
L- Natural Conditions
The results of modeling the original natural conditions are
shown in Fig 18 The excavation and stream to tne west of Rose
Hill Road and tne landfill did not exist in this simulation The
southwestern boundary consists of a drainage stream that was
delineated using an aerial photograph and stream elevations were set
using the topographical map The USGS ground-water map (18) was
used to estimate head values between the west excavation and north
streams These were input to the model as constant heads on the
models western boundary The resulting simulation generally matches
the southeasterly flow direction that is indicated on the
ground-water map (Fig 5)
A3
Legend
x-^- stream 400 = = = unimproved road
I f ee t
Fig 18 Natural Conditions
44
Excavation Without Landfill
The condition of the excavation to the west of Rose Hill Road
with its resultant drainage stream without the landfill was modeled
next (Fig 19) The extent of the excavation ana the location of
the new drainage stream were delineated using the aerial
photograph The west stream elevations were sited in the field and
used in the model The concept of a confining streamoed layer was
excluded in tne excavation drainage stream under the concept tnat no
significant organic layer had been built up within the 25 year
period that the excavation had been initiated Head values between
the west and north stream boundaries were interpolated and input as
constant head values on the northwestern boundary The west
excavation drainage stream creates a condition that alters the
natural ground-water flow patterns by creating a more southerly flow
condition the drainage stream providing a more immediate surface
outflow in that area
Landfill Without Excavation
The hypothetical case of a landfill without the excavation was
modeled next (Fig 20) The low hydraulic conductivity zone of the
landfill changes the natural flow conditions and creates noticeable
mounding This is evidenced by the decreased spacing of the head
contour lines and deviation from the lateral contour lines of the
natural conditions and higher head values (Fig 21)
45
Legend
excava t i on s t ream
400 unimproved road
f e e t
Fig19 Excavat ion without Landfill
46
Legend
landfill limit
bull - s t ream 400 copy WNWNEECSESC
monitoring well locations f ee t bullbull-bull=bull unimproved road
Fig 20 Landfill without Excavation
1
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48
Landfill ana Excavation
The condition of tne existing landfill and the excavation with
the dam is the next condition modeled (Fig 22) The ground-water
elevations used to calibrate tne model correspond to an actual high
water table condition Between the NVJ and pound weir a streamflow loss
of approximately 102 gpm occurs aoout 60 percent of this flow is
lost at the dam site which maintains a head of b-6 feet over an area
of approximately 1800 feet^ This approximates a field value of
1144 gpm influent to the aduifer between the NW and E weir on ]2
December 1981 (Table 3) From the E weir to the SE weir a net
increase in flow occurred of 74 gpm which corresponds to field
increase of b62 gpm
The surface runoff from tne landfill flows primarily toward tne
eastern side of the landfill Increases in water-table elevations
on the eastern side after heavy rains such as the 11 November 1981
storm indicates that this runoff increases outflow gradients to the
stream and therefore increases streamflow Surface runoff input is
not modeled which explains in part why field stream inflow values
are slightly higher than model predictions especially for periods
after a storm has occurred The flow from the SW weir located at
the southern end of the excavation represents drainage outflows from
that area The net flow calculated in the model was 140 gpm
which approximates field conditions of 1642 gpm on
December 9 1981
49
d f l f reg N E
shy
Legend
landfill limit -bullgt-bullgt- excavation ^-N_X- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road
-40mdash approximate groundwater contour
400
feet
Fig 22 Landfill and Excavation with Dam
50
The modeled flow patterns suggest how the various contamination
zones around the landfill have developed to their present state
They indicate a flow to both the southeast and southwest on their
respective sides of the groundwater divide Evidence of a
southwesterly contaminant flow is presented when the continued high
specific conductance contaminant level in tne observation seepage
hole is realized (Table 5 ) In addition the specific conductance
increase in the west excavation stream is evidence of an influent
contamination flow
Contamination flow to the eastern and southeastern side of the
landfill is obvious High specific conductance levels in the wells
on the eastern side (Table 4 ) a specific conductance increase
between the E and SE weirs (Table 5 ) and contamination in the NE
domestic supply well (Fig 3) present conclusive evidence of
contamination to the eastern side of the landfill
An anamalous condition that exists is a domestic supply well
located approximately 300 feet due south of the landfill remains
uncontaminated (Fig 3) Flow patterns indicate that contamination
would be transported from the landfill south to this area
(Fig 14) One explanation is that a pocket of clay at the southern
end of the landfill area was discovered in the original excavation
for the landfill (lt6) This evidently prevents leachate from
reaching this wells radius of influence
51
Summer Conaitlon
As described earlier during dry months of the year the stream
that normally borders the northern and eastern side of the lanafill
may dry up as far as a point southeast of the E well Tnis
condition existed from the 15 August 1981 to the 27 October 1981
period when streamflow commenced in the northern part of the stream
yet did not overflow the north dam until 17 November 1981 This
created the present day continuous flow condition throughout the
stream These summer conditions were modeled by removing the stream
above the aforementioned location while other conditions remained
the same (Fig 23) Summer condition well water levels listed in the
model generally match field low water table conditions (Fig 9)
Because there is no stream upgradient from the landfill to provide a
stream head and infiltration through the streambed groundwater
runoff from the area north of the lanafill is the controlling flow
input In these moaels an average recharge of 14 inyr was used
which represents a yearly average The summer recnarge conditions
are prooably lower given the effects of decreased rainfall and
increased evapotranspiration during the summer months A domestic
supply well whicn exists northeast of the landfill (Fig 3) nas a
greater potential to be contaminated from the lanafill at tnis time
than when the stream is flowing Flow patterns from the landfill
are such that during an upper stream no-flow condition groundwater
flow patterns are more in an easterly direction than in a
southeasterly direction The stream would act as a source of
infiltrated water upgradient from tne landfill and provide a
52
I ^N gt i I i j i -r- -bull- bullr -T- t- -r- i- TJ JV
bullbullT laquo ^ O - laquo bdquo xi cshy
H r^~ I -~- --^ X- = mdash x^ N
^--^ A bull O^NW -v - gt-bull Ni i I _____mdash - bull laquo l - mdashmdash 1 deg I ^ltv I C
I reg NE A
Js bull vbull A ~ - v T gt- ^ ix - N
-5Z- | N TfS lV I -bull bull iA i gt gt I ^ bullr-Ky L bull 1 _- copy]wgt-- - bull- mdash - - shy
= r Y ~mdash ltmdashA A
^^-lt A _ - - - - bull Hmdash - reg EC x ^-mdash mdash I ---mdash_mdash -t-V-^N - y
I- -bull - r x i X
V ^ 7 I -v (^~~^^r ^^^
sc Emdash-bull vV JI - - - ~ r )N y- -
X - bull r bulllt
^bull^ y y Jlaquo^ - -lt shy
T s^ lt^ ^ +^-b (
X
Legend
landfill limit j-j-bullraquobull excavat ion gt^ -x- s t ream
reg WNWNEECSESC monitoring well locat ions
= == unimproved road fee t
Fig 23 Summer Condition
400
53
constant head across tne northern section of the landfill This
would tend to orient the flow in a more southerly aowngradient
direction In addition the stream which flows adjacent to the
northeastern well could provide a source of infiltrated clean water
to it which would minimize the possible contamination from landfill
leachate
Without Dam
During tne spring scream flow condition the dam failure which
occurred between the 15 March 1982 ana 9 April 1982 monitoring
periods decreased flow to the aauifer and landfill This eliminated
the 5-6 foot head difference over a 19000 ft^ area which had
created a larger area and elevation head for infiltration to occur
The condition without the dam was modeled by reducing the area
encompassed by the dam to a 4 foot wide stream channel thus
reducing the leakance value at that node (Fig 24) The flow change
from the stream to the aduifer between the NW weir and E weir
reduced the model flow loss to 50 gpm Tnis corresponds to the 9
April 1982 monitoring period which indicates a 30 gpm loss
As compared to the previous flow loss in the upper stream
sections to the aauifer the 21 April 1982 and 22 May 1982
measurements between the NW and E weirs indicate a flow gain The
streamflow conditions have changed from an influent
stream-to-aauifer condition to an effluent aduifer-to-stream
condition that increases flow downstream
54
Legend
landfill limit j--i--i- excava t ion x-gtmdash^- stream 400
copy WNWNEECSESC monitoring well locations
= == unimproved road f e e t
Fig 24 Landfill and Excavation without Dam
55
Analysis and Discussion
In order to fully understand flow patterns and Quantify leachate
outflows at the landfill it is necessary to arrive at an estimate
of flow inputs from precipitation ana upgradient sources In the
following analysis it will be demonstrated that the rainfall input
to the landfill is the factor which controls leachate generation A
calculation using the H inyr recharge over the area of the
landfill was made to estimate the leachate outflow due to rainfall
infiltration An estimated 134 gpm is generated from the entire
landfill area Simulation of the existing conditions (Fig 24)
indicates a groundwater divide in the landfill is located
approximately at the western third Therefore approximately 23 of
the generated leachate flows to the eastern side of the landfill or
9 gpm The effect of the flow input from the upgradient stream is
evident when tne summer condition witnout the stream is viewed
(Fig 23) Without the stream to infiltrate the landfill and the
recharge and northern boundary condition as the flow inputs the
head at the northern end of the landfill drops about 5 feet from its
previous value A flow pattern from the north central part of the
landfill to the eastern side indicates a 12 feet head difference
with recharge - but with the upgradient stream a 16 foot head
difference occurs Considering the transmissivity change the
stream would increase the leacnate outflow from the landfill
approximately 43 under a low water table stream influent condition
to the aauifer This would increase leachate outflow to the east
side to approximately 129 gpm This value approximates the
56
outflow at the SE weir location during the summer monitoring period
when the upper stream was not flowing (Table 3) The outflow from
the western third of the landfill whicn lies to the west of the
ground-water divide would be approximately 63 gpm
Realizing the importance of infiltration to tne landfill as a
major influence on the generation of leachate an analysis of this
w i ll be discussed An estimate of infiltration was made using the
precipitation recora for October ana November (Appendix A) During
this time period a minimum of direct evaporation ana
evapotranspiration occured and the grouna is not yet frozen The
top cover over the lanafill is generally 05 ft to 2 ft of local
sandy soil and subsoil availability determined what was used The
top of the landfill is at an elevation of 92 ft as compared to the
ground surface at well W which is at an elevation of 76 ft
(Fig 25) This compares to the well W water level which is at an
elevation of approximately 52 ft This creates a long path for
infiltration through the unsaturated zone The topcover generally
slopes eastwara at a grade of 2-5 The west side maintains a
relatively steep slope of 10-15 ft drop within 50 ft ana the north
and eastern slopes have a more gentle slope of approximately 10 ft
within 100 ft distance An unlined surface arainage swale channels
surface runoff from the northern section of the landfill past the
NE well to the eastern side ana low area in the vicinity of the E
well This has a drainage swale to an area near the stream but
doesnt directly connect to tne stream A poorly graaed drainage
swale exists on the landfills left side The landfill material has
57
excavation
seepage observation ^
hole
Legend bullmdash landfill limit -^--excavation limit r^s- stream
copy WNWNEECSeSCSEN monitoring well locations
--- unimproved road O location of amp Inf i l t rometers O
feet
Fig 25 Infi ltrometer Locat ion and Drainage Feature
58
been placed in 10-12 ft cells and covered with 1 ft of soil at the
end of each day The material has settled differentially creating
areas for depression storage
An estimate of the percentage of precipitation that infiltrates
the landfill was made from precipitation records recorded well
elevations and an estimated specific yield for the landfill
material The volume of water that infiltrated should eaual tne
specific yield multiplied by the well water level rise Several
recharge periods were studied using this relationship Once the
percentage of precipitation that has infiltrated is determined the
percentage that is translated into runoff is simply the remaining
percentage if evaporation is neglected
From the literature for a slightly inclined slope of 2-5
typical runoff coefficients range from 10-20 in either sandy or
heavy soil (16) The landfill cover is generally sloping to the
east which creates a long path (approximately 400 ft) before the
runoff reaches the steeper slope on the eastern side of the landfill
of 15-20 The long drainage distance creates a greater time for
rainfall to infiltrate Another consideration is the actual
capacity of the soil to conauct water into the soil which was tested
in the field using double ring infiltrometers An average initial
percolation of 8 mmhr the first hour and a subseauent rate of b
mmhr occurred (Fig 26) The 8 mmhr rate compares well with
other sandy soil infiltration rates (14) Therefore if the
intensity of the rainfall exceeded a 5 mmhr rate for several hours
59
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E o
CO
o Z pound C
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C9
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CO
CD CM
ogt CO N- to -4 CO CM
jq tuu i U O | raquo B J J | | J U |
60
on a poorly drained surface the additional rainfall would be
translated into runoff because the soils infiltration capacity had
been exceeded
The initial 8 mmhr infiltration rate was due to the pore spaces
in the sandy soil being filled and the subsequent 5 mmhr rate was
percolation into the low permeability landfill material The tests
were conducted in November assuming a minimal evapotranspiration
and the field capacity of the sandy soil had been maintainea
The W well was used as representative of the water elevation
changes in the landfill because it is directly adjacent to the
landfill 900 ft distant from the upgradient stream This minimizes
the effect of infiltration from the stream and maintains a high
contaminant level During periods of high runoff conditions excess
surface water ponded in a poorly graded drainage swale on the west
side and directly adjacent to the landfill This influenced the W
well at a time the contamination level dropped (Fig 11) Before
this occurence in mid-December the rise of the W well closely
matches that of the SC well and a background well SK6 which is
located outside the study area (Fig 7) Therefore it was analyzed
as a valia indication of the water level rise during the mid-October
to mid-December period The monitoring of the SC well was
intermittent due to inaccessaoility because of 10 ft extensions
being placed on the well as the refuse was being filled in arouna it
61
A high rainfall period from 14 November 1981 to 1 December 1981
was chosen for the initial study period The effects of
evapotranspiration were neglected due to the cool temperatures
experienced at this time Therefore it was assumed that the field
capacity haa been reachea and tnat any additional input to tne
unsaturated zone would result in direct percolation to tne saturated
zone During the time period 14 November 1981 to 22 November 1981
029 ft of rainfall fell and the well W rose from 488 ft to 493
ft - a 05 ft increase During the next 8 day period there was no
precipitation yet the W well continued to rise to 4972 - a 042 ft
increase The slow percolation of water through the landfill
material would account for the latent rise in the well water level
From previous reports a specific yield for refuse was estimated to
be 028 (1920) This value is dependent on the original compaction
of tne material age and resulting consolidation
During the 14 November 1981 to 1 December 1981 period 029 ft
of rain fell and the well increased 092 ft The following
relationship is used to evaluate the infiltration value and runoff
I = (Sy) h
Sy = specific yield
h = well rise
I = volume infiltrated
I = (028) (092 ft) = 0261 ft
62
The difference between the precipitation and the infiltration is
the runoff (assuming no evapotranspiration) Therefore 029 - 026 =
003 and furthermore 003029 - 13 runoff This corresponds in
the literature to a typical runoff coefficient for an inclined
surface of 2-5
Analyzing a longer precipitation period from 18 October 1981 to
1 December 1981 a net precipitation of 043 ft (accounts for
evaporation) occurred less 10 for runoff or 039 ft infiltrated
This results in a 139 ft elevation increase The well water level
actually increased 132 ft shy only a 5 deviation from the
calculated
From tnis investigation it is seen that a large proportion of
the precipitation has the potential to be transmitted into the
landfills saturated zone Exceptions are wnen heavy precipitation
periods exceed the soil percolation capacity frozen ground prevents
infiltration and direct evaporation and evapotranspiration recycles
the ponded surface water and infiltrated soil moisture back to the
atmosphere In retrospect water temperatures within the monitoring
wells could have been measured to indicate thermal effects from the
landfill on ground-water temperature Ground-water temperatures
were assumed to be 50deg F (9)
63
Specific conductance measurements serve as an indication of
contamination levels These measurements are used to trace leachate
movement which represents ground-water flow patterns Factors which
must be considered when monitoring pollutants are the attenuation of
the leachate contaminants which occurs both in the zone of aeration
and the saturated zone The former is a more complete process
Dilution dispersion and cation exchange are the primary factors
involved in decreasing leachate concentration in the saturated
zone The glacial outwash materials of southern Rhode Island do not
have a cation exchange capacity or a high buffering capacity so
attenuation is simply by dilution and dispersion (22)
The NW well consistently exhibits relatively low specific
conductance levels even though it is in landfill material It is
situated in a drainage swale and ground water elevations range from
543 to 5944 This is several feet below the upgradient stream
elevation of 64 feet which is less than 400 feet away The bottom
of the wellpoint is at an elevation of 5312 feet well into the
landfill material Infiltration from the stream to the landfill has
occurred at this location
The W well is situated on a bedrock high adjacent to the
landfill approximately 900 feet from the upgradient stream and its
water level is higher in elevation than the excavated pit (West
Observation Hole) which is 300 feet directly west The W well
maintains a contaminated level A poorly graded drainage swale to
the west of the landfill provides areas for extensive ponding and
infiltration to occur which explains the drop in conductance after
a high runoff period
64
The SC well is located in landfill material and has a
conductance of over 8000 umhos This indicates that leachate is
undiluted The oottom of the wellpoint is at an elevation of 389
feet which is situated in the landfill material
High specific conductance measurements in the west observation
hole and well W and their relative elevations indicate a
west-southwesterly flow direction from the landfill Infiltration
recharge and leakance from the stream into the landfill provides the
necessary elevation to cause outflow in this direction
Contamination from the landfill to the surrounding streams is
evident (Table 4) During the period 15 August 1981 to 27 Octooer
1981 there was no flow in the stream that Borders the northern and
eastern side of the landfill until a point just south of the E well
was reached High specific conductance levels in the EC and NE
wells were recorded (1000 jjmnos) At a point directly east of well
EC a pool of water existed that was relatively uncontaminated which
is designated as the East Stream] location (Fig 10) At a point
just south of that (East Stream^ polluted water in the streambed
was flowing at a low rate This was measured at the SE weir
location and which had a high conductance also Flowrates varied
between 6 and 23 gpm and specific conductances were over 350
pmhos This low water table condition flowrate is the baseflow from
the eastern side of the landfill and indicates a southeasterly flow
direction from it
Streamflow commenced in tne northern part of the stream 21
October 1931 and the north dam oegan to f i l l Stream specific
65
conductances were low indicating a clean water source Tnis
continued until 17 November 1981 when the dam overflowed ana flow
throughout the east stream began A weir was placed at the Rose
Hill Road NW location and was compared to flowrates at the SE
location Flowrates decreased and specific conductances increased
between these two locations
To further investigate the condition of a lower flowrate
downstream than upstream an intermediate weir was placed at the E
weir location (Fig 9) This snowed tnat the stream from the M
weir to the E weir was losing water to the aauifer (influent
condition) and gaining water at the SE weir (effluent condition)
The condition of a net loss of water between the NW and SE weirs
remained until 19 December 1981 when a snowmelt rain condition
caused increased surface runoff and a net increase in flow at the SE
location Upon analyzing the March and April 1982 streamflow
conditions the expected case of a net ground-water pickup from the
E to SE weir continued The explanation for tne initial net loss of
ground-water is the fact that the leakance from the upstream section
was being discharged into aauifer storage to raise the ground-water
table to an eduilibrium level Upon reaching a high recharge
equilibrium steady state condition any additional input will
eventually be transmitted as baseflow out of the landfill and a
downstream net pickup will occur A hign water table condition
prevailed during the January through May period maintaining this
condition In April the north dam broke through reducing the head
in that area by 4-6 feet The 9 April 1982 monitoring revealed that
66
an influent condition remained between the NW and E weirs but at a
reduced rate The 21 April lower stream flow condition shows a
small pickup of water between the NW and E weirs indicating the nigh
water table and low stream flow conaitions combined with the absence
of the dam had changed the conditions to an effluent condition
This was evident in the May monitoring period
Evidence of contamination on both the western and eastern sides
of the landfill supports the existence of a ground-water divide in
the landfill The west stream which drains the excavated area to
the west of Rose Hill Road shows contamination pickup between its
northern section and the SW weir The W well and ooservation hole
indicate high contamination levels which reinforces the concept of a
contaminant outflow to tne west excavation stream
As shown previously flow towara the eastern side of the
landfill is evident from the nign specific conductances and specific
conductances increases in the stream This is especially evident
during low flow conditions when the stream starts at a point to the
east of the landfill and flows with high specific conductance levels
From the literature a relationship between specific conductance
and dissolved solids exists the dissolved solids (mg1) are
approximately equal to the specific conductance times a factor
ranging between 55 and 09 (39) in this case it is taken as
065 (41) The dissolved solids increase coupled with the stream
flow increases provides a basis of calculating the dissolved solids
outflow to tne stream This calculation method was used in a
previous study (26)
67
The relationship
=Cinout Coutflow Qoutflow - Cupstream Qupstream Qinput
where the numerator is the streamflow pickup and the C- and
Q-jnput is the concentration and flow input from the ground-water
This can be used to estimate dilution level outflows from the
landfill Initially this is used for the ambient ground-water
pickup between the E weir and the SE weir This entire flow doesnt
come from tne lanafill but much of it is conaucted in the high
transmissivity area between the lanafill and stream from upstream
leaxage ana surficial recharge Tnis is evident when this section
of the flow pattern is analyzed on Fig 22 Therefore the landfill
outflow is mixed with tne ambient groundwater flow which dilutes the
landfill leachate before it enters the stream To illustrate-this
concept a calculation using the 9 December 1981 monitoring is used
At this time a flow of 672 gpm occurred at the SE weir with a
specific conductance increase of 7 ymhos between the E and SE
weirs The dissolved solids increase would be approximately 795
Today in tne stream
Where
Co = 90 jumho at SE weir
Qo = 672 gpm at SE weir
Cus = 83 jumho at E weir
Qus = 606 gpm at E weir
Qinput = 66 gpm gain
Cinput = 154 jumho
68
The 154 jumho value represents the contaminant level in the
ground-water adjacent to the landfill
This relationship is applied to approximate the concentration
level dilution in the ambient ground-water between the landfill and
stream The aforementioned relationsnip is in turn applied to the
landfill outflow into the ambient ground-water flow adjacent to the
landfill The ground-water receives landfill leachate dilutes it
and then transmits it to the stream The previously calculated
value of 129 gpm was used as the outflow from the landfill
Co 154 jumho flows into stream
Qo = 67 gpm flow into stream
Cus = 83 jumho background level
Qus = 67 gpm - 129 gpm = 541 gpm
Qinput = 129 gpm from landfill
Cinput = 451 jumhos
Approximately tne same contaminant levels from the landfill (tbl
umho) are arrived at as existed in the summer streamflow conditions
when the upgradient ground-water flow adjacent to the landfill was
at a minimum
In addition to using specific conductance to define
contamination zones electrical resistivity can be used to indicate
contaminated areas The measured earth resistivity is inversely
proportional to the conductivity of ground-water Water containing
contaminants with high ionic concentrations are more electrically
conductive and will have lower resistivity values than surrounding
natural ground water Therefore resistivity methods can be used to
69
delineate plumes of contaminated ground-water that have hign
specific conductances This has been demonstrated by several
investigations (11122328374045)
In this study a Schlumberger vertical electrical sounding R-l
was made in an area of known contamination at the W well (Fig 12)
Given the geologic constraints provided by the well boring log a 4
layer computer model was used to match field survey values A
Schlumberger sounding R-2 in an uncontaminated area north of the
landfill in the same geologic setting was used to provide a
comparison background sounding (Fig 12) A seismic survey N-4 was
made to obtain water table depth and depth to bedrock as input
parameters to a four layer resistivity model (Fig 8) Tne results
of the electrical soundings have been tabulated in Table 6 and
plotted in Fig 27 and 28 respectively
The ascending portion of the field Schlumberger curves were
initially matched using a two-layer ascending type master curve to
provide an approximate depth and apparent resistivity of the
overburdened topsoil layer (8) Tne second unsaturated layers
apparent resistivity was determined by using the graphical
interpretation of total transverse resistance The total transverse
resistance is approximately eoual to the peak value of the curve
times the corresponding Ab2 distance it occurred at This in turn
is eaual to the sum of the first two layers apparent resistivity
times their corresponding layer depths
70
bullH
OJ bull bullH 4J CO CM
c ce G bullrH
j-gt ca c c a 3 ltu O L
co CO 0
bullo Q bull laquos c n 3 -U OrH f~ 3 bO ltn y CO O cc CO ^mdashN
QQ bull
bO bOJJ C C Ci_i
O l T i O O O O O O O O O O O O O O O O bullH bullH mdash^ bullo 0 C c3 f| 3 O raquo O CO CQ
CO
rH
CO O
L 4J
^ltU
i- 1 ^n ^b O 4-) bull2 CM bullH C OJ 1 -U bullH CO C L O a ^-^ 0) a
rH c a L CD ltu (1) 3 tlt bO cO I
3 a 0) a Q 4J laquoa e CO 3 (H bO c C O bullH
CO TJ C 3 bull
bull O bO -i-3
0 CO C O3- O G O O O O O O O O O O O O O O O O O O ft rt1 -raquo - t l S^ ft tfigt f I mdash^ K_ l_ raquo mdash I gt fgt I l 1
(1) 0 rH CO CJ JD o^^ CO CO CQH lts
71
Legend
A actual field measurement
-e- interpretat ion
10000 bull
6000 bull 5000
4000-
3000shy
pound2000| ltD
_ r 1000
09
5 600 pound 500 - 400
I 300 a a lt 200
100 10
Fig 27
20 30 4050 100
Distance AB2
Schlumberger Sounding
200
feet
R-1
400 600
72
loooot
6000 5000 4000
3000+
laquo2000 e
r 1000
raquo 600 pound 600 ~ 400
$ 300 a a lt 200
100
Legend
A actual field measurement
-Qmdashinterpretation
10 20 30 40 50 100 200 400 600 Distance AB2 feet
Fig 28 Schlumberger Sounding R-2
73
Formula T = f
Background Sounding (9000)(15) = (3110j (1 7) + gt2(8)
= 16214 n- ft
W Wel l Sounding (b200)(60) = (500) (2) + pound2(28)
= 13250 SL- ft
To determine a resistivityp3 value for the third layer a
graphical interpretation for the longitudinal conductance S was
used(48) This is eaual to the sum of each individual layers depth
divided by their apparent resistivity
Formula S = -r1 +~r-raquobull-ra
Background Sounding 0017 = yyg + ~^
= IbOU - ft
W Well Sounding 0285 raquo -ggg 7^3 J~
= 179 v-ft
These values were input to a program which calculates a
schlumberger sounding curve (47) The theoretical sounding curves
approximately match the field curve as viewed on fig 27 and fig
28 To provide a check on the apparent resistivity of the saturated
layer at the W well the following relationship was applied 1OOOO
= spec-jfic conductance (umhos)
74
At the W well the specific conductance was measured to be 3 00
jmhos at approximately 10degC
Assuming a formation factor of 45 for the glacial outwash (23)
material Archies law is applied to estimate an apparent resistivity
of the third layer (7)
fgt FF x p
A= 45 x 103-n-ft
A= 4G3 JL-ft
This is a reasonable approximation to tne 3i= 179^-ft calculated
analytically from the sounding curve interpretation
75
Remedial Measures
With the analysis of f low patterns and contamination zones
recommendations to minimize the environmental impact of the leachate
can be reviewed The basic technique is to minimize all sources of
water reaching the refuse so that leacnate production is minimized
The oiversion of precipitation by a relatively impermeable cover and
proper channeling of runoff would minimize percolation into landfill
material Caps and seals can be constructed of clays fly ash
soils soil-cement lime stabilized soil memorane liners
bituminous concrete and asphalttar materials (15) Proper
contouring and grading will help minimize infiltration If a soil
cover is used a vegetative cover can be planted which will utilize
some of the infiltrating flow through evapotranspiration losses
during the growing season By minimizing the length of slopes and
providing proper drainage channels tne surface runoff can be
conveyed to a downgradient area outside the recharge zone
Therefore this surface water will not increase leachate production
from the landfill Also by increasing the slope of the cover over
the landfill itself a higher percentage of runoff and lower
infiltration will occur
To minimize upgradient ground-water influx to the landfill an
impermeable subsurface barrier or intercepting trench could be
used Barriers can be made of bentonite slurry-trench cutoff walls
grout curtains or sheet piling cutoff wal ls extending to the bedrocic
or an impervious layer to effectively prevent water passage or
create a head loss that wil l lower the water table In addition an
76
intercepting trench which has a perforated drain at tne lowest part
of the water seepage zone could be used to intercept and divert the
entire flow
These possibilities have been evaluated with the help of the
model to determine workable solutions for this landfill The
primary concern is to eliminate leachate flows to domestic wells
Initially a simulation was run that eliminated recharge over tne
landfill area (Fig 29) This had a considerable effect on the
ground-water flow patterns of the landfill area The mounding that
had previously occurred under normal recharge conditions was
eliminated and a general drop in the water taole within the landfill
of 2-3 ft occurred The effect of eliminating recnarge over the
landfill when the upper stream is running would cause greater
infiltration from the stream as evidenced by only a 2 ft head loss
in the landfills flow conditions This is evident when comparing
Fig 29 with Fig 24 Tnis indicates that this measure would only
marginally reduce the resultant leachate flow from the landfill
material that lies below the water table In another situation
where there is not such a strong potential for upgradient flow this
measure has proven quite effective (6) In this case the landfill
cover consisted of four layers an intermediate sand and gravel
cover immediately above tne regraded waste materials a 4 inch sana
bed designed to protect the overlying membrane a ilO mil flexible
PVC membrane and an 18 inch final cover of sand and gravel
77
Legend
landfill limit -raquo- -^ -raquobull excava t ion x-^x- s t ream
400 copy WNWNEECSESC monitoring well locations
= -= unimproved road fee t
Fig 29 No Recharge over Landfill
78
Controls such as 10-30 mil polyvinyl chloride covers favor the
development of an anaerobic environment which increases waste
decomposition time and would necessitate installation of gas vents
at several locations on the landfill cover Tne integrity of tne
synthetic cap may be further threatened by subsidence which create
differential stresses on liners Settlement would create areas for
ponding and depression storage and eventually necessitate regrading
the landfill surface The landfills south-central area has oeen
filled within the last year and will prooably need to be regraded
due to settlement within the next few years
Another possibility for a liner would be a soil-bentonite
cover A layered cover consisting of natural materials with low
permeabilities such as bentonite clay followed by a layer of highly
permeable material such as sand and finally a layer of topsoil can
be used Due to potential drying out and cracking of the clay liner
a synthetic liner is the preferred method
The most immediate technique is to grade contour and vegetate
the landfill cover which has been done at this site Althougn an
impermeable cover would probaoly reduce the amount of leachate
produced it would not eliminate the upgradient flow and provide
guaranteed protection of wells in the vicinity of the landfills
northwestern section
A slurry trench along the northwestern perimeter of the landfill
would effectively cutoff upgradient infiltration and divert recharge
infiltration in a southeasterly direction thus removing possible
leachate outflows from the radius of influence of the neighooring
79
wells This has been simulated using the computer moael ana flow
patterns as shown in Fig 30 Contour lines are distorted in the
vicinity of the slurry trench due to the 200 ft nodal spacing
Transmissivity values of 1 ftday were input at the slurry
locations to simulate an impermeable barrier Tne surface recharge
at those nodes does not infiltrate the relatively impermeable grid
nodes at the slurry locations and flows to the edge of the noae
thus creating a dramatic head loss within a short spacing To
effectively simulate this a variable grid spacing should be used
with reduced node grid spacing at trench locations to eliminate
distortion The computer simulation shows that the slurry trench
could direct flow in the landfill area in a southeasterly direction
and away from endangered wells In addition it would reduce
upgradient infiltration from the stream into the landfill This
measure would prevent leachate from spreading beyond this carrier to
possibly contaminate neighboring wells
The combination of both the slurry wall and impermeable cover
would be ideal measures to minimize generation of leachate and to
stop its spread to neighboring wells The slurry wall without
recharge over it or the landfill is simulated in Fig 31 This
indicates a lower water table tnan eliminating the recharge to the
landfill The slurry wall has blocked upgradient ground-water flow
at its location to the landfill
80
Legend
landfill limit -laquo- j -laquobull excava t ion ^^- stream
copy WNWNEECSESC monitoring well locations
= = = unimproved road ssi slurry wall
f e e t
Fig 30 Slurry Wall
81
Legend
landfill limit j- j- J- excavat ion x-v^gt- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road s==s slurry wall
400
feet
Fig 31 Slurry Wall without Recharge Over It or Landfill
82
An intercepting drainage trench is considered next If a trench
was excavated to a 30 ft depth in the outwash material extensive
shoring would be required In addition difficulties would arise
when the trench was excavated below the waterline Tne trench would
be sloped to provide drainage and backfilled with a highly pervious
material to intercept and divert leacnate locally a conouit which
is perforated on the top to allow infiltration and unperforated on
its lower perimeter to permit continuous drainage to the collection
treatment center would be installed on the bottom of the graded
trench The difficulties involved in excavating below the water
table ano shoring the sidewalls to permit implacement of a drainage
conduit at a 30 foot depth make this option increasingly infeasible
83
Conclusions and Recommendations
The location of the South Kingstown landfill in permeable sand
and gravel glacial outwash material (107 ftday) combined with the
high hydraulic gradient across the landfill area (20 ft1600 ft)
creates a high potential for ground-water contamination to occur
This is intensified because refuse nas been placed below the water
table The low hydraulic conductivity of the compacted refuse (1
ftday) and the excavated area to the west of Rose Hill Road have
both contributed to modifying the original southeasterly flow
pattern These modifications have created a ground-water divide in
the landfill at approximately the western third section Tnis
results in approximately 13 of the leachate flow from the landfill
or 63 gpm flowing in a southwesterly direction and 23 or 129
gpm flows in a southeasterly direction Infiltration from
precipitation recnarge over the landfill (up to 9Upound) and from tne
upgradient stream during low water-table periods provides tne
necessary influx into the landfill Evidence of contamination is
clearly seen on both the east and west sides of the landfill which
reinforces the previously stated flow patterns
Of the several remedial measures reviewed the contouring and
grading of the landfill topcover and drainage swale provides the
most immediate protection The topcover has been graded mulched
and seeded to provide a low runoff slope generally to the east
The drainage swale on the left side of the landfill has improperly
graded sections which should be corrected Its northern section
could be drained into the northern sections swale and the southern
84
section drained to the southeastern section of the landfill Tne
point of the drainage swale which divides the northern drainage
swale from the southern one should be determined by a field survey
Cost is a major contributing factor when determining which
remedial measure is to be applied to the given situation For the
purpose of this report cost estimates are not presented but rather
the effectiveness and feasibility of the remedial measures are tne
primary considerations As was reviewed and simulated in the
computer models the slurry trench and impermeable cover over the
landfill are two viable options that would effectively provide
protection to the domestic supply wells in tne vicinity The
impermeable cover would eliminate precipitation recharge into tne
landfill yet drop the water table only a few feet due to upgradient
infiltration from the stream This would decrease the hydraulic
gradient thus diminishing the potential for a contaminant outflow to
surrounding wells The supply well of primary concern is one to the
west of Rose Hi l l Road marked well D on Fig 2 If contamination
occurs in this well the most effective measure would be to block
off leachate flow in this direction by installing a bentonite slurry
trench at the location indicated previously This would effectively
prevent leachate flow in the westerly direction and diverts it to a
more southeasterly direction In addition the slurry trench
precludes infiltration flow into the landfill from the upgradient
stream
85
Tnis report has effectively reviewed tne original ana existing
flow conditions and contaminant levels in the vicinity of the Rose
Hill landfill The purpose was to provide an understanding of
ground-water contamination patterns and study possiole remedial
measures
86lt
Appendix A
Precipitation Records
Monthly normal precipitation 1941 -197O
i$l Total monthly precipitation
KINGSTON RI
14
ia
^JO T I bullbullL
pound 111 laquobull
4
a
n
-
^
-
-
KS1JAN
^Ii R3 HB MAR
1
1 APR MAY
1
1 JUN
1981
JUL
-bullraquolaquo H
AUO SEP
K3~~f$s bull
_imdash
i1S 1
OCf NOV OtC
171 1 iI1
JAN HB MAR APR MAY
198
Fig 32 Precipitation Record
- - - -
IM 1 MtvJrflgtlgt c ortli-A t lUN I r nraquo rl - -
gt|MO CLIMATOLOQICAL OUSERV ATIONshyr-r bull JK gt raquo - 1
i5fWA I VAPOR Al IOH -bull AIM If MPCRATUM bullF 0 riccipn AT ION UNO IlMf
bull 14 H 14 H mdash Vshy ADDITIONAL DATA IfUAlUS OATt 1 bull raquof bull bull 1 ta
14 Hw rlaquo4 w bullbull bull 1 114 1mdash4 (llrl 1 1 1fl Hll
0 kmdash
Mraquo M4 raquo i T i 4 bullraquo-laquobull i i
Lgt f 1 21 S 1 Hbull - - bullbull -
ltJL 1 2 01 - - _ _ 1
mdash
-
1 12 _ Q I
mdash shy
mdash 4 (C ( - - fVi 1 - 0
1 (1
^ 1
Vvraquolaquo IJ1^ raquo CP O 3L 1 Z - i bull j-t-J
1 J
LH Vb T n 0
1 gt fl oo O ~l 2 L - bull 1 P )laquo jn iP IP - OOI L5L mdash shy
-t 84 ^(^^ ^fi P i flja 0 JO II 10 tl tcgt 7 J IV wllaquo
h l2L bull 0 lt -_ shy
-id VJ lt 3C 2 ft OOL -mdash
U 71 C1 Sr 2 13 2 nl JLJraquopound HP r M ltf1- (
IMe 2 ii O It
n jlt dl 1 1 bull o o-il ST i 1 i 25 2-x-1
-
ri
i tlL O mdash gtbull bullgtlt 1ft -o- is Oil So iJK 2-io otv u 31 fil loi 2 il Oll it Of wr is i1raquo -iZ 1 deg|0 01
M IT So - mdash
- 13 1 CT mdash i - mdash 21
shy
Tl Ci av ZUll IMT 0 IM Pe v _ 1) T) S) ii3( dlt Ii 2 lt^2 II li- S1 riivi To 7HX lt3lO 14 ^2- iTi I li 011 -- - -i -^IS no 5^ or i | T Jift laquoV OoH bullla It Va iCO mdash L OIL 11 bullvf poundgtpound lS_ flv oh P-lfe 1 poif _ shy11 IB kl (4 itlaquoT lamp llt0 oot^
mdash -n
It T1 |ir( L1 HI 2 0 oil
U 1M ft go C ICf^ -^2 Z laquo-|o
11 it 5 bulln - TO o abull Li u-i IT1 -- Iw O ltM (I bullbull bdquo-I(K 1mdash -tilltLlA ttfe
i Dgt ac -- U 44 4 11 1 1- ytd i i_i J-K 0 i if -i i i V t Wl raquoOHM 1-1 US D C P A R T M f N T OF COMMfRCE t 4 1 IUII 1 1 ^~) mdash
llaquo- Hi NC bull bullh bull bullJL^V HBl CO 00
11
)jLsVyr^gturv
^ | TKu
|-_t_ bull(
IIMgt I I Mt|UU III- II 11
PNECIPITATIOH
I 1 1 IMX
IMO
bull llfclaquo I UCIUKI) Ur C V A r U M A AHO CLIMATOUOCICAL OBitH
E V A F O R A T I C r i Jttffl laquo amp hMIlaquoJllaquoJIIlaquoBgt
DATE AOOITIOMAL DAIAKMAKk M
bullraquobullmdashlaquo
tp 01 (1 Of Ll OOI ooo
0^1 o-i 10 tl |00 102
OC (1 13 Ofl
it i rc DS os an
(1 SV o
Ul 010
(ISl 101 I on
130
II 5= Otl
ss lt 001 (IK Ml
jt il HIT
7 it
ow Wo 17 Top 2-01 OIO
(0 oov zi oot
u CO ^A 0 to Zoi CLflS
bull50 01 ljtj
nshy 5H LO OIt
50121 IVO QJO
14 Co Ho LO Hl ^pound Jl 1
ltM ool fllc
H Tl 01 II
11 11 Q1
iH OIO
HO 2 llaquol 11 II
lifc
IV-IIM ul OIPAITHINT or COHMIICC NOAA
NAtlOHAL gtIATnlaquoll raquotraquoVlClaquo CD
r~
All TCUMMATUNI ^V UII rgt ITmi 1 Cwphu Obic i gtn t ngir-H 30
rilCiriTATIOH
JJ T I rTJ-rimdashr-iramj|MP CLmATOLOQ
laquolaquo jftilCiii bullIHO
Oi1l ADOITIOHAL DAIAlllu
Ilf4ft
Sii1
(1 2 IO OO
Hl ii SO
us OIM
Q^L
a A3 Hi SZ Sf^ bull 12J2
HI Z-SF OOl 1C t HM IA H ICP fiJA
OOl 10 (310 sn 310
if HI (0 ^01
bullit SO 28H poundJ1 11 006
14 35 TX oon II (bull2 it zr II c-S
rr Zll lo 31 OP an 31 a 31 oor
CSW O-ll Si CC Of 011
Oll _ I |ft
00
u i oerraquolaquoTMiMr of c NOAA
NATIONAL K C A T N C M SCMVlCC
TC^S lk)oiVroTJA
TETT I 7X
1raquolaquolaquo 4 bdquo ir lt er ni I^OV ltqgl j--^ TQ
MICiriTAllOH ITIND
D|mdash
b5NO ctiUATOtoiCAL oeit^
OATI AOOITIOMAL OATAVlHAtt
0-tt
Mlaquoh bullbullbull- rshy laquo
I- ltltriu HI I 4 bulllaquobullbull1
Zii
30 Dfellt otvt
at HA
OOI
62
iJ_S2 HI if
bull- 20 SI 2i So
So
VVfr
OSfc
I (
Jtlt
3aoi
r j -bull ie MA
Irill iiol
in^ 14
Mo
Zll
214
21 1P
00-i
bulliron
17
bullr
11 i ir- I J Ktf^c
US D E P A R T M E N T OF COuMEDCC I | C gt A A
K AIlaquo Ttupf lATuit r
|SlVi AlJ PIICIPITATION
oJud (El
VIM i Uraquo
MIND E
EVAPORATIOH flnrft bull A ftufiifccdll
KECORO OF eVAPllHAtlil bull I CLIHATOLOOCAL OBSERVA ^Hij
14 MM A_M AOOIIIONAL DATA11 MAIM
Mr bullH Oo|
M Si lift
bull221 IHI
ZS Ji 40 IZV
icr KS I
HZ 111
bullT 21
loA UK JA IP
v^ ft
1M 2Sshy IT Tl
71 V |
i I 31 1deg a
uty^ U bull3
ons 1 CiO TxX
HHO (10
3H 19 12 10 IP
raquo3H raquo | 5t io
OP OIT
14
vO UI Of PANTMINI Or COMMCRCf MM O A A
F ngt TIHH
iiicffwiffc 4 rJ (TIM bull Cempltit Obitittiio
AIlaquo TIMHIATUM PHICinTATION I V A f OK ATlPrl
OATI ADDITIONAL DATA KMAlIt
U4laquo4 +
03H Ji
10
rc a 1 16 oi ii
tiiy 10
OI
II i23 or o 13 -y~ou HO
II 3V III i 3 t
V laquop oot
OM1 SS ne
T an -i IP
Olt zr LTV
3T 001
a -11 2T
10 an 31
-1 raquo 131 UP 3H lf 14 Lpoundshy
it 14 30
IS
Ui O I P A K T M f H T OP COWlf ICfM O A A
NATJONAI V C A T M C n f t K M V l C K
bullbullbullbullbullshy -2 o AIlaquo TIMMRATUM f fKICIPITATIOH
OATI poundt- MMINMAL DATAk
ZP 51 lo icr
011 111
OoT IHf
Ut 003 am
3o 13 ao
4A X 05shy
H4 i IjJyiV131 ooc js
IH oi 01 tL 18 13 a
No 11-7
rivgtp OO| M Hi 03 01
It 12
bull I 41 bull7119 14 ^^ raquo 31 15 lampk n M ho i
Jo -j-
-J
I
Ml H^ I _
amp2ampUi^= LS 0 S 0-f bullTTT
-Vmdash gt U_ bull 1 rOHM I- 11 OI OCPARTMlNT OF COMM(NCC
HO NATIONAL W f A T M f H ftfraquoVlCI
98
Appendix B
Boring Logs
99
X iHECT 1 ff 2
OAT American Drilling amp Bor ini I Co Inc
wo WATH smn EAST PR ov IDENC E ft 1 Town of South Kingstown South K ngstown R I MOLENO X-J
TC 100 RCSS bull ujrMonitorinq Well Installation | South Kinqjtown R I UNC a STA Pf KXICCTHJ LOC ATK3N
bull cfrserrr TO above S MPLES S FNTTO _ _ |laquolaquor A-109 SURF ELEV RE PORTSEr
GROUND WATER O6SE RVATC MS 1 CDREraquolaquo m-T nn75 laquo A 256 - 20 mdash Hew y
Instolled 32ofT-l2 PV C - JO- COMPUTE 111275 K toia 3- I-WI 1-38 TOTAL MRS bdquo10 screen BORING FCACUAM J K lanq MAI rraquo HomnwWI 300 140 IampPCCrc Mamlaquor Fall 24 30 lampaaiona SOLS ENGR
LOCATION OF BORING H ONITOKING WELL
Coung Samplt Tjp Blow per 6 Manure SOU IDENTIFICATION Strata SAMPLE ^^^yV Bloot
foot
Otptni
From- To
el
l
on Sampler
0-6 1 -6-13 12-18
Dentity or
Conmt j
Chang Remark include colo^ graaation Type of tod lie Rao-coMr type condition nordshynetiDntotf time leamt and tie No Pen Rtlt
2 No top sample 5 12
1 loamy fine sand
bull)^ 40 30 36
5- 616 0 23 20 16
noist iense
Brown fine to coarse SAND some fine to coarse gravel Trace silt
^
1 18 18
36 8-0shy57 40 30 V 35
|0-||-6 D 14 24 20 Srown medium to coarse SAND Some fine gravel cobbles
7 IRshy 16
27 75 37 3
IS- I- D 5 14 16 3bull
ISshy 15
42 50 I9--0shy50 65 20-2ll-6 D 9 23 26 bull Jrown fine to coarse SAND Tbullwshy 1Z 75 90
22-0 Trace silt trace fine gravel
124 120 74 60 52 41
7S-ltlaquoil-A DX 71 16 13 wet very dense
Gray-brown fine to coarse SANC Some fine to coarse gravel little silt
H IR u
40 30--0
3C-30-IO
3l4-334
334-3314
38 4-434
D
c
C
C
7 IflO
94 6
we tr j
y se
ft irox
30MOshy
31 -4shy
Gray-brown fine to coarse SAND Trace silt
Gray-brown fine SAND some lilt trace fine gravel
Too of Rock 31 -4shy
Gray-pink GRANITE
6 7
amp
CJ
IltJ A
60
601
IQ mdash
2(
4
5 i Hard
ft 5ome seams bull
GROUND SURFACE TO J 4 U3CD_ ^JVrf bullbull( tutu t to 4o 4 SampM Type Proportion UMd MOB Wtx 3 OfaM on 2OD Sampler SUMMARY-
OOry CCartd WltWen4 Hoc OlolO Canmonieraquoi Don any CoKeem CarMWncy Earm Barrlaquoj 11 14
UPgtUnOigtturod Piuon trite (Oto20dego 0-Kgt Loei it 0-4 Sait 3O+Hofd Rock Corng 14 Kgt-30 laquo4 0 rte 4-8 MSHM Samplet TPTtitPit Ai Auger Vvanefett tarn 2Olo39 3O-M Owlt n laquo-lS Strlf rinit nn v 1
UTiUndlshffbed ThrMOll and bull 33to9O 5O Very 0laquo nraquoe 19-30 V-3trraquof - | OLE NO X-l
TOVH rim - iA it raquotoraquo
100
SHEET 2 o_L
WO WATEt STUET [AST ft OVIDENC pound a i American Drilling amp Bor ing Co Inc
MCLl WQ X- 1 Tt AOORCSS i
LIME A STA KXICCTMJ tuf same as 1 | tame as i LOCATION
W PORTSEf mo OB nj urt eflaquo T
illtPLES S
P
CVTTO nlaquo mun orv
^s f^ Tin i GRCVMO WATER OBSERVATONS CASING SAMPLER CORE BAR
START Typi COMPUTE tome at 1 same aiH
TOTAL MRS BORIMG FOR CMAN n bull IT INSPECTOR SOILS EMM
LOCATION OF BORING u HfVJTneTfi UFI _
8
Counf Blo-t
foot
Dtpllo
From To
0( on SampMr
0-6 f 6-IZ
Moittir
Oonuty or
Contilt
Strata Ctnngc
SOIL OCNTiriCATION Rtmorkt ineHifl cotot grqdotion Typlaquo of Mil etc Roo-axtrPlaquo condition Mrdshynlaquot Drog tun ttomt end tic
SAMPLE
No Ptfl RfK
434-4o4 c
approx 7 minj
per toot 454
Gray pink GRANITE Hard Fairly solid core
lt_4 24
Bottom of Boring 45 -4
-
~
bull 1
GROUND Sorrow Tye
SURHCZ 10
bull OiOry CgtCord WWothod UPUnditiurMd Piston TPlaquoTtraquotPtt AtAuotr VVor
UTltUndinrvd TTMMO bull bulltat
iivnPilaquo(onioni Uraquot4
me OioiOItttt laquoraquo20
wmt Z0ie33
and 361090
c M
C1 5 Si
-SOshy
ASING
IOtgtWtigt bullnlot Dn 10 Loci M Mod 04 SO Dm 1shy Viry 0laquo
s _
TMEN 0 hMl on 200 SoiTBUr laquoity ConcMMt Conorawncy gtbull 0-4 Sort 30shym 4-B MStlfl M BH9 Strtf bull ts-so v-swt bull
t-HOrt Ear Bern RoetCorrt
i ^^^^^ bull
-[MOLE no x-i
101
raquoMEC rAmerican Drilling amp Bor in g Co Inc 1 ofj_ DATE wo WATlaquo smn UST Plaquo IOIDCNC j laquo i
Town of South Kingstown South Kingstown 8 MOLE MO Jlt Z TC rx MCS3
rtprr uAurMonitorina Well Initollation | South KinqitowrxRI UNC A STA P KATIOM ME POCT ^rwT TO above I OFFSZT
uD^r laquorlaquorTTO 6 -109 suw tLEv Sgt louffJOCNO
0 tj Tlmlaquo WOUND WATER 06SCRVATC US gtW Rsdl SING SAM^EH CORE BAH
26 ^_ 12 $TAlaquoT UL 2Z2i Ji r TTP NW ltA sr IJZC Z5 CCOMPLETE
SitLO 3 I-3B- 1-38 TOTAL MAS 41 BOAINO FOACMAN JK1 ana nf ni n MonwwWl 300^ 140 BIT bullK^CT
gttonvrar Foil J^laquo 30mdash Diamond SOOJIEMGM
IE HFII
iCaunq SampM Trplaquo BMMtpw6 UOIIIK- SOIL DCMTIFKATION Siraia SAUPLE Blow DlaquoPIAraquo of on SompMr HtmorU mcJuo cotes gradation Type of Dwuily
pw or CXang writK Roel-eolorlyp condition tvort-From- To Vfoot 0-6 f 6-2 12-18 Coniitt egt rwtiOnAngtimt wamaondtte No Praquon Rtlt
2 Brown fine SAND little silt 2 2-0shy5 15 18 moist Browi fin to coarse SAND 18 5- 6-6 0 14 25 27 vlaquo Troc fin aravel | 25 wy Ifl 11
dlt tns 35 40 38 moist n in-il-i Lgt U 15 18 ie is li1 Irl IS 31 I2-0
~~43 1
A) Jrown coars to medium SAI MD 48 moist Little fine to coarse gravel
|5-IA-Xlaquo 14 47 41 fn D laquo y Little silt rrqa coarse sane 3 18 I1
68 In IS 44 32 34
n ^n-^i-A- w 2o 19 29 wet 4 la -59 lens ltfO no
25-0 2amp bulllaquo- 77 c BOULDER r[ 4 i
27-0 5X ~W 24 24 bullWar- 5 Ifl irown tine to coarse SAND some
dens 29-0- Fine-coars gravel trace silt
30-3I oxx 30 32 30 moist irown -gray fine SANDiom e 6 l rr Vlaquoy 31 -0 silt trace fine oroveTILL
Bottom of Boring 31 -ampbull shyBent casing -pulled out and moved over 4 - washed amp tJrovlaquo casing to 30 -Installed 3C gtof 1-12- PVC - 10 screen
WOUND SUraquoraquofCE TO 3pound 1 yijfD MW t ASIMC TMCJ laquo olaquorod -bor of borina
SomoU T]Fplaquo ProigtuliOraquoH UMd MIOtgtWLx3Orolt lon2OASanlaquoMr SUUMARY-D=Dry CCorad Wlaquoworaquonraquod bullact OiaiO CanM gnMM Daonty CIMIH Caamraquoci EffW 8or^ 2pt
UPiUnairurMd Pition Itnt laquoM2O O- O UKraquolaquo 0-4 Soft 3O-hHard Roelaquo Corrig o- JO M0mlaquo 4-8 MSNff SOTipM 1 p^ 3O-9O OwgtM bull-IS Slid
TPlaquoTraquojraquoPit AAugtr ViVon mini tamt 20to39 UTtundiifir6d TrwMOtf and JSloSO 50-raquobull Vary 0nlaquo [HOLE NO x-2 B-3O V-3Mf lev rim - IAIT raquosectlaquoraquo
102
300 iu 24
1 UMnii ffi 140 laquo 30
CA1INC tf
gt taWCTf
bull 0gtlaquo i R Cook Jr_ R Millineton1 Wttn
I~
1 VAMtl CtMG
1 W HO-t MO
1 Oraquo 1 laquo0~ twt
L 1 laquo-raquo VfcM^lf [wlaquoraquoCI ^ ^ K3Ot III laquo
0-LS D
5-65 D
LlQ 10-115 D
15-16 Tgt
Lraquo 70-51 n
25-26 D
F
I O-O Ci
A Allstate Drill ins Co vi o i
PROVIDING R 1bull raquoraquo uvraquonn~ N M O M I T O P I N G HE1 _^lt -^ PI-Traquo UJU
CUM Town of South Kineraquotown raquoraquo 1 1TA maoer Propolaquolaquod Sit for Slude Disposal nltn
laquo V-449 iampAAtut i a 138 ort STI bull r 42777 CtOuMO IKVtllON
Cill bdquo 258 DA II MN ru 42777 rilaquolaquodO laquoraquoTti rum 1911
AU1TATI
MMUI1 raquolaquogtlaquolaquo laquoKiO itXHHKraquoriOi of sous MUAHI nMTKlion Ot CMlaquoMC|kOraquort tl CO~VH DXltgt raquomlaquo laquotf IMi COIOI C4l II I 1raquo gtlaquo^ Oraquo 1Ol rC t Xgttgt VtfKOe Craquo Mi 1 ft liMraquoK laquo0^tlaquot nfgt
1-2-1 10 TOP SOIL FINE LIGHT BROWN SAND traclaquo of ilt
16-31-17
22-24-21 100 FINE TO MEDIUM LIGHT GRAY SAND trace of fine gravlaquol and raquopoundLt
lfl-37-34 150 LIGHT BROWN FINE TO MEDIUM SAND little poundinlaquo gravel
21-17-15 200 MEDIUM TO COARSE SAND bullomc fine gravel
12-4-10
265
Observation well installed
NOTE No casing blows taktn
bullbull B-23 ow
^w^ 265 I raquo bull raquolaquo bull I W
11 laquot gtbullraquo Vlaquo 14 W gt_ c-shyji bull alaquo bull jraquo VI laquoHshyw bullbull m raquobullbull D-6 raquo Mshy
bull bull laquo Vshy
1
bull bull
I
103
MAMMII Allstate Drilling Co ulaquorr 1 or 1 FftOVIOCKZ H L traquolS mTArm^S MONITOR NR WEL
VNO wr3JJO__raquoraquou_24__ HCU MO P-74 n iu riBwi Town of Slt7H^ Xirpin
mdash^ laquo0J P 1 1 bull ^n^ciit^o TVlaquow^laquott1 bullraquoit wt 140 nu 30 olaquor fBu lkv Waste Disposal Arcai
MUTAH a V-449 R Cook Jr UMlaquoiigti D 1 38 0t| raquoIJ raquo 5277 rlaquo SUMO luvlaquorv-laquow
mdash 5277 fipe -raquoT pfpm 150
H MCIO IMNTlXAflON Of SOU t(kAIlaquoS rrn 0-laquoraquo
5 -SF 01 w in laquobull -raquo ^ lit
D 1-2-2 TOP SOIL V-1-oraquo
15 IPbull FINE TO MEDIUM LIGHT GRAY SAND AND GRAVEL
5-65 D 37-27-35 some silt
10-11 D 20-14-18
15-165 D i 17-14-14 155
BROWN COARSE TO MEDIUM SAND little fine to coarse gravel trace of silt
20-211 D 4-4-2
230 GRAY BROWN VERY FINE SAND
25-26J D 7-8-9 AND SILT 265 fvarvedl
Observation well installed
NOTE No casing blows taken
wta 10 n uuraquo c^imdashbull IgtM laquolaquobull- B-24 ow ~ 14 ltfc laquoraquobull vlaquo^ M laquobull r O 0 fmtt bull W-L 26 5
-0- CgtCmdashgt bull laquolaquobull mdash laquo 1 - raquoraquo 1 gt 1laquo bull 1 gtraquor to bull mdashbull bull bull bulllaquo I t l~laquo 1lt Uraquo mdashbull ) bull 1 gtbull ft 0~ H laquoy bullM ta bull -IN la laquobull OPUM bull($ IMI
mdash H raquo laquo-bull
104
Appendix C
Calibration of Specific Conductance Meters
105
Specific conductance measurements were made using a beckman RB
338 temperature compensating meter and a YSI rtooel 33 salinity
conductivity temperature meter The YSI meter is not
temperature correcting A formula to compensate for temperature
differences to standardize YSI measurements was used (21)
A long probe for the Beckman meter was used to measure conductivity
in the wells Differences in conductivity between the YSI ana
Beckman meters and the Beckman short and long probes exist These
were calibrated in the laboratory using 001 N and 01 N KC1
solutions Values presented are Beckman short probe values The
Beckman long probe values were reduced by 76 and tne YSI values
were multiplied by 11 to adjust to Beckman short probe values The
YSI meter was used in the latter phases of the study for the
stream contamination due to the greater accuracy of the dial readout
scale
Table 7 Specific Conductance Meter Calibration Table
Concentration (KCL) 0001N 001N
Specific Beckman short 145 143 143 1247 1245 12GO
Conductances Beckman long 190 191 188 1639 1650 1665
umhocm 9 25 C YSI 132 131 128 1131 1140 1150
average values Beckman shortBeckman long = 075
Beckman shortYSI = 11
106
Appendix D
Computer program Flow Chart
107
F1g 33 Computer Program Flow Chart-
1TpoundR MAP TCO
NEWPER
WEWSTP CZAX
HEWIT TRANS TCOF ROW COLUMN
Yes
Yes
108 The following is a description of the USGS two-dimensional computer
program Iterative Digital Model for Aquifer Evaluation updated
December 1972 by P C Trescott The program written in Fortran
consists of a MAIN program and six subprograms or subroutines which
themselves are organized into subprogram sections The subroutines and
their sections are listed below
MAIN Program
DATAIN (subroutine) COEF ITER (section) CLAY MAP TRANS NEWPER TCOF
ETRATE COMPUT STORAG
NEWSTP LEAKAG NEWIT1 NEWITO CHECK ROW CWRITE COLUMN STEADY PRNTA OUTPUT DRY BLOCK DATA
The program begins in the MAIN program which controls the sequence
of passage to the subroutines Sequential steps are described in the
program as shown in the flow chart of Fig 32 Emphasis is placed on the
steady state confined aquifer case as applied in this study First data
input is read in the DATAIN subroutine This data includes transmissivities
or permeabilities starting heads storage coefficients and grid spacings
Nodal transmissivity values are then computed for the water-table problem
in the TRANS section (COEF subroutine) This procedure is necessary here
because the subsequent routine for computing iteration parameters (ITER)
keys on nodal transmissivity values which would not have been input to
the water-table problem In the water-table option these would have been
109
computed from given bedrock and water-table elevations to obtain the
saturated thickness component of the transmissivity calculation In this
study water-table option was not used and the transmissivity values were
input directly The program then passes to the ITER section (DATAIN
subroutine) to compute the iteration parameters which expediate or even
cause convergence Next the MAP section (DATAIN subroutine) is utilized
to initialize data for an alphanumeric map if this was requested in the
input options Transmissivities are then computed for the confined
(artesian) aquifer case (water table not specified with input options)
in the TCOF section (COEF subroutine) These coefficients are harmonic
mean values of adjacent nodal transmissivities weighted by grid sizes
Time parameters and pumping data for a new pumping period are then read
in the NEWPER section (DATAIN subroutine) followed by entry into the
NEWSTP section (COMPUT subroutine) which calculates the size of the
time step Leakage coefficients (hydraulic conductivity of the confining
bed divided by confining bed thickness) are next computed in the CLAY
section (COEF subroutine) if leakage was specified in the input data
which was used in this study
A new iteration is then initiated in sections NEWITO (COMPUT
subroutine) NEWITO saves the current head values and compares them to
the updated head values for determining closure This is followed by
nodal transmissivity values being computed for the water table or water-
table artesian conversion problem Transmissivity coefficients are then
computed for the water-table problem in TCOF (COEF subroutine) Total
head values are then computed with the alternating direction implicit
procedure using the Thomas algorithim first along rows in the ROW section
110 and then along columns in the COLUMN section both in the COMPUT subroutine
Then if a solution is not obtained (because the error criteria for
closure is not satisfied) the MAIN program branches back to NEWIT1 subshy
sequent sections TRANS TCOF ROW and COLUMN repeatedly until a
solution at the particular time step is achieved NEWIT1 increments the
iteration counter and is immediately followed by NEWITO The program then
moves to the STEADY section of the COMPUT subroutine to check if the
closure criteria for steady state has been satisfied Output is then
printed in the OUTPUT section of COMPUT if steady state has been reached
or if the particular time step is designated for output
The program then branches back to NEWSTP (COMPUT subroutine) and
moves through the subsequent routines until the last time step in the
pumping period is reached Output is then promoted in the DRY section
of COMPUT if specified in input data If the last pumping period in
the problem has not been reached the program branches back to the
NEWPER section and moves again through subsequent sections otherwise
the program will terminate or start a new problem if one follows
This study was simulated as a steady state problem which can be
simulated by setting the storage coefficient of the aquifer and the
specific storage of the confining bed to zero and using one time step
of any length
111
Appendix E
Computer Data Sheets
RGSEA
10 ROSE HILL LANDFILL MODEL 20 30 40 LEAKAGE 50 60 70 CHECK 80 90 100 HEAD 110 120 1 23 IQ 100 5 001 37E-OU 0 130 100 001 0 0 1 4 0 - 1 - 1 1 - 1 - 1 i i i i i i 1
ISO 1 10 0 1547E-05 01 10 1 1 160 04642 200 200 1 1 i it
1QO 190
CARDS I THROUGH 19 - CODING SHEET
CHEAD
100 110 120 130 131 132 140 141 142 150 151 152 160 161 162 163 164 165 170 171 172 173 174 175 176 177 178 179 1BO 101 190 191 192
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 539
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 58
25
25
25
25
25
25 621
25
25
25
25
25 662
25 25
25
CARD SET 2 - STARTING HEAD MATRIX (FT)
193 194 IVb 196 197 190 200 201 202 210 211 212 220 221 222 223 bull 224 225 230 231 232 233 234 235 236 237 23B 239 240 241 250 251 252 253 254 255
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 23 25 25 25 25 25
25 25 - 25 25 25 25 25 25 25 25 25- 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 - 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25
25 25
25
25 25
25 25
25 25
25
25 25
25
25 25
25
25
25
25 25
25 25
25
25 25
25 25
25 25
25
25
25 25
25
25 25
CARD SET 2 - STARTING HEAD MATRIX (FT) - continued
STORC 1512 FRI 19 FEB 82
100 110 -1 -1 - 1 - 1 0 0 120 130 140 ISO 160 170 100 190 200 210 220 230 240 230 251 260 261 262 263 270 271
CARD SET 3 - STORAGE COEFFICENT
LEAK
100 110 120 02 130 _ 18 02
I ltu 18140 025 150 02015015015 19 deg25
02 160 022 bull-laquo- J1 5 j 1 z laquo- l^
170 015 180 016 laquo02
190 016 OE025
200 02504019022021025 2 5 i S lt03 0252i2 n
230 030 deg23 deg2 deg2 deg2 -02023023 240 022 250 022025025 02
027043 013025
30() 025025025 310 025031 320 024025
CARD SET 5 - AREA OF STEAMBEDAREA OF NODE
120
Appendix F
Bibliography
121 BIBLIOGRAPHY
1 Agpar MA and 0 Langmuir Ground-Water Pollution Potential of a Landfill Above tne Water Table Groundwater V 9 No 6 1971 pp 76-96
2 Allen William B Hahn GW and RA Brackley Availability of Ground Water Upper Pawcatuck River Basin Rhode Island USGS US Government Printing-office GS 66-624 19bb
3 Annual Book of ASTM Standards Part 31 Open Channel Flow Measurement of Water and Waste Water by Weirs D 2034-68 1975
4 Annual Book of ASTM Standards Part 19 Infiltration Rate of Soils in Field Using Double-Ring Infiltrameters D 3385-75 1975
5 Baeaecner MJ and W BacK Hyarogeological Processes and Chemical Reactions of a Landfill Ground Water V 17 no 5 1979 pp 429-437
6 Beck WW Dunn AL and Grover H Emrich Leachate Quality Improvements After Top Sealing1 8th SHwRD MERL Symposium 1982
7 Beckman WK Transient Modeling For Estimating Sustained Aauifer Yield master thesis presented to the University of Rhode Island Kingston RI 1978
8 Bhattacharya PK and HP Patra Direct Current Geoelectric Sounding Elsevier Publishing Co New York 1968 135 p
9 Bouwer H Ground Water Hydrology McGraw-Hill Book Co New Yoric 1978 p 378
10 Braids 0 Cocozza pound Fenn D Isbister J Rous P and B Yarc Procedures Manual for Ground Water Monitoring at Solid Waste Disposal Facilities Environmental Protection Agency530SW-611 Cincinnati Ohio 1977
11 Cartwright K and MR McComas Geophysical Surveys in the Vicinity of Sanitary Landfills in Northeastern Illinois Groundwater V 6 no 5 1968 pp 23-30
12 Cartwright K and Fd Sherman Jr Electrical Earth Resistivity Surveying in Landfill Investigations Reprinted from Proceedings of ohe lOtn Annual Engineering and Soils Engineering Symposium Moscow Idaho 1972
122 13 Clark TP Survey of Ground-Water Protection Methods for
Illinois Landfills Groundwater V 13 no 4 1975 pp 321-331
14 Dunne T and LB Leapold Water in Environmental Planning WH Freeman and Company San Francisco 1978
15 Faro DG Upgrading Hazardous Waste Disposal Sites Remedial Approaches US Environmental Protection Agency500SW-677 Cincinnati Onio 1978
16 Fenn DG Hanley KJ and TV Degeare Use of the Water Balance Method for Predicting Leachate Generation From Solia Waste Disposal Sites US Environmental Protection Agency530SW-lfa8 Cincinnati Ohio 1975
17 Geisser 0 An Electric Analog and Digital Computer Model of the Chipuxet Ground Water^ Aquifer Kingston Rhode Island master thesis presented to the University of Rhode Island Kingston RI 1975
18 Hahn GW Groundwater Map of the Narragansett Pier Quadrangle Rhode Island Rhode Island Water Resources Coordinating Board GWM 5 1959
19 Hemsley William T Koster C Wallace Remedial Technique of Controlling and Treating Low Volume Leachate Discharge USEPA National Conference on Management of Uncontrolled Hazardous Waste Sites Oct 1980
20 Hughes GM RA Landon and RN Farvolden Hydrogeology of Solid Waste Disposal Sites in Northeastern Illinois Final Report to US Environmental Protection Agency PUD SW-l^d Cincinnati Ohio 1971
21 Keller GV and FC Frischknecht Electrical Methods in Geophysical Prospecting Pergamon Press New YorK NY 19bb
22 Kelly WE West Kingston Landfill An Evaluation of Its Effect on Ground-Water Quality Rnoae Island Water Resources Board Water Information Series Report 1975
23 Kelly WE Geoelectric Sounding for Delineating Ground-Water Contamination Groundwater V 14 No 1 1976 pp fa-10
24 Kelly WE Ground-Water Pollution Near a Landfill ASCE Environmental Engineering Division Journal V 10 No EE6 Dec 19b pp nay-nyy
25 Kelly WE personal communication January 1982
123
26 Kelly WE and OW Urish A Study of the Effects of Salt Storage Practices on Surface ana Ground Water Quality in Rhode Island NTIS FHWA-RI-RD-8001 1981 54 p
27 Kimmel GE and OC Braids Leachate Plumes in a Highly Permeable Aauifer Groundwater y 12 no 6 1974 pp 388-393
28 Klefstaa G Senalein LVA ana RC Palmauist Limitations of the Electrical Resistivity Method in Landfill Investigations Groundwater V 13 No 5 1975 pp 418-427
29 Landon RA Application of Hydrogeology to the Selection of Refuse Disposal Sites Groundwater V 7 no b 19b9 pp 9-13
30 Lang SM Bierschenk WH ana WB Allen 1960 Hyaraulic Characteristics of Glacial Outwash in Rhode Island Rhode Islana Water Resources Coordinating Board Bulletin No 3
31 LeGrand HE Patterns of Contaminated Zones of Water in the Ground Water Resources Research v 1 No 1 1965
32 Palmauist R and L Sendlein The Configuration of Contamination Enclaves from Refuse Disposal Sites on Floodplains Grouna Water v 13 no 2 1975 pp 167-181
33 Pinder GF A Digital Model for Aauifer Evaluation Techniaues of Water Resources Investigations of the US Geological Survey Bk 7 Cl 1970
34 Purushattam D Tamxe GR and CM Stoffel Leachate Production at Sanitary Landfill Sites ASCE Environmental Engineering Division Journal V 103 no EE 6 Dec1977 pp 981-988
35 Remson I Fungaroli AA ana AW Lawrence Water Movement in an Unsaturated Sanitary Landfill ASCE Sanitary Engineering Division Journal v 94 no SA2 April1968 pp 307-316
36 Rosenshien JS Gouthier JB and WB Allen Hydrologic Characteristics and Sustained Yield of Principal Ground-Water Units Potowamut-Wickford Area Rhoae Island USGS US Government Printing Office GS 67-324 1968
37 Roux PH and B Vincent Electrical Resistivity Evaluations At Solid Waste Disposal Facilities US Environmental Protection Agency SW-729 Cincinnati Ohio 1978
124
38 Salvato JA Wi lk ie WG and BE Mead Sanitary Landfill Leaching Prevention and Control Water Pollution Control Federation Journal v 43 no 10 Oct 1971 pp 2084-2100
39 Sawyer CN and PL McCarty Chemistry for Environmental Engineering McGraw Hill 1978
40 Stellar RL and P Roux Earth Resist ivi ty Surveys - A Method for Defining Ground-Water Contamination Ground Water v 13 no 2 1975 pp 145-150
41 Todd OK Ground Water Hydrology John Wi ley and Sons Inc New York 1959
42 Tolman AL Ballestero AP Beck WW and GH Emrich Guidance Mannual For Minimizing Pollution From Waste Disposal Sites US Environmental Protection Agency-500SW-677 Cincinnati Ohio 1978
43 Trescott PC Iterative Digital Model for Aauifer Evaluation US Geological Survey Open file report 1972
44 University of Rhode Island Academic Computer Center CalComp Contouring Manual
45 Warner DL Preliminary Field Studies Using Earth Resistivity Measurements for Delineating Zones of Contaminated Ground Water Groundwater v 7 1969 pp 9-16
46 White EF A Report to the Town of S Kingstown Utility Survey Engineering Corp 1967
47 Zohdy AAR A Computer Program for the Calculation of Schlumberger Sounding Curves Over Horizontally Layered Media Using the Method of Convolution US Geological Survey Denver
48 Zohdy AAR Eaton GP and DR Mabey Application of Surface Geophysics to Ground-Water Investigations Technidues of Water-Resources Investigations of the US Geological Survey Book 2 Chapter 01 Washington US Government Printing Office 2401-02543 1974
seepage observation -t West
hole Landfill Area
Legend mdash landfill limit bull j--excavation limit r^-s stream copy WNWNEECSeuroSCSEN
monitoring well locations = = = unimproved road
A contaminated domesti supply well
D uncontaminated domestic supply well
feet
Fig 3 Supply Well Locations
5
a 03
N lo ^ gt
laquo c 2
mdash w
3
X o ^
3 O L
o CO
0 opound E bullo
0
co
c
o0
uj ^
0 o o c
o $ bullA
E c o
w
bullo t_hraquo9 O
_OplusmnJ ca
u
pro
ve I 51 H
bullo 0gt
UJ _c e poundbullo Mzbull w gt 0
laquorege cc
0gt -^^ o a5 raquobull bullo o sect 3 mdash laquoo o wcz _
3Ogt c $c o_ X
aw e 05 0 (0 3 bullo
o a 2 2 u
hydraulic properties and the subsurface geometry enable estimates of
ground-water outflow to be made Streamflow measurements were used
to verify these outflows Contamination levels using specific
conductance measurements as an indicator were measured in wells
streams and observation holes to help delineate the extent ana
degree of contamination An electrical resistivity sounding was
conducted in a known contamination zone
The primary objective of tnis study is to determine flow
patterns in the vicinity of the landfill ana recommend possible
actions to contain or minimize the impact of the contamination In
oraer to fully evaluate these goals the aforementioned parameters
were input to a computer model to produce simulated flow patterns
under different conditions The simulated present conditions were
matched with field water table and stream flow measurements to
calibrate the model A series of simulations were then run to
evaluate flow conditions before the excavations anaor landfill
existed Remedial measures such as reducing recharge to the
landfill and implementing a slurry wall to blocx off leachate flow
to endangered wells were simulated to evaluate their effectiveness
Based on this analysis recommendations are made as to how to
minimize leachate production ano best alleviate the immediate danger
of the contaminant plume spreading to unpolluted domestic supply
wells
background
The South Kingstown landfill is in a geologic setting that is
very similiar to the nearby West Kingston landfill This is located
about 3 miles west of the South Kingstown landfill and has been
studied to assess leachate effects on groundwater quality using
specific conductance as an indicator of contamination levels
(222ltt) Both sites were located in abandoned gravel Quarries which
were filled in with refuse to create the landfill
In the literature numerous authors have shown that the character
of contaminant plumes from landfills are largely dependent on the
local geology and geohydrology A study on Long Island (27) in
similiar glacial material illustrates that the Quantity of flow is
dependent on the hydraulic conductivity of tne aauifer the
hydraulic gradient and the vertical cross-sectional area of the
aauifer it flows through This is expressed as Darcys Law (41)
Q = KIA
wnere Q = flow quantity
I = hydraulic gradient
K = hydraulic conductivity of the aauifer
A = vertical cross sectional area of the flow area
Specific conductance was used as a contaminant tracer to show that
the plume from the landfill flowed downgradient and vertically
through the full thickness of the aauifer A study in Iowa (32)
indicates that the size ana shape of the contamination outflow from
a l a n d f i l l can be predicted from existing geohydrologic conditions
and that the horizontal shape of the outflow extends downgradient
8
from the source and parallel to ground-water flow lines Other
parameters which control the extent of the contaminant plume are
dilution and dispersion in the aquifer and the adsorption properties
of the aauifer material (31)
The amount of leachate generated depends largely on the amount
of water that infiltrates through the landfill to increase tne water
content of the refuse in the landfill The precipitation recharge
that percolates down through the unsaturated zone to the water table
moves in a vertical direction (35) Surface runoff soil moisture
storage losses and evapotranspiration account for tne precipitation
that is not transmitted tnrough the unsaturated zone of aeration
(3315) Upon reaching the saturated zone the water enters the
ground-water flow system Ground-water mounding has been reported
in landfills due to the decreased hydraulic conductivity of
compacted refuse relative to surrounding aauifer material (20)
Chemical processes within the landfill leachate outflow and
surrounding soil cation exchange capacity relative to water duality
of the surrounding aduifer have been studied in Pennsylvania (1) anu
in Delaware (5) A procedures manual for ground-water monitoring at
solid waste disposal facilities was developed by the US
Environmental Protection Agency (USEPA) (9)
Several reports have been written that investigate site
selection design criteria and remedial measures to correct
leachate problems (29) A survey of ground-water protection methods
for landfills in Illinois studies relationships to the water table
theory of liner installation and monitoring devices (13) Sanitary
Landfi11-Leaching Prevention and Control presents a review of
preventative methods such as means to minimize infiltration
interception of ground-water and other pollution control measures
(2 37) A study in Pennsylvania on actual measures implemented to
collect and treat a landfills leachate discharge presents a site
specific study (19) Leachate Quality Improvements After Top
Sealing1 shows that by minimizing infiltration at a landfill in
Connecticut the outflow leachate water quality can be improved
dramatically and contamination plume reduced significantly (6) The
most comprehensive reports on remedial approaches to upgrading waste
disposal sites and ground-water protection methods have been
compiled under USEPA contract (1542)
To assist in evaluating remedial measures the US Geological
Survey (USGS) computer model Iterative Digital Model for Aduifer
Evaluation was used It was originally developed as a model for
simulating two-dimensional aauifer problems (33) It had been
updated since its original development to accomodate different
options (43) This model has been applied to glacial outwash
regions in Rhode Island (717)
10
Description of Study Area
A map of tne landfill area (Fig Z) was obtained from tne town
of South Kingstown The excavation to the west of Rose Hill Roaa
the landfill area directly to the east and the presently operating
area to the east of the central stream comprise tne overall study
area This study will concentrate on the west landfill area whicn
has recently reached capacity and been closed to further dumping
This site received mixed refuse for the past 15 years The depth of
the excavation where the landfill presently exists was approximately
to bedrock in some places Tne exact depths of landfill material is
unknown
The landfill cover has been graded and sloped generally eastward
to convey surface runoff to the eastern side A sandy soil that was
excavated locally was used as tne cover material The northern
section has a vegetation cover and the recently filled southern
section has been seeded and mulched The six monitoring wells W
NW NE EC SE SC were placed by the town of South Kingstown to
provide water quality information
Referring to Fig 2 the west excavation stream drains the area
created by the excavation to the west of Rose Hill Road and flows
throughout the year The central stream drains a small watershed
area which lies to the northwest of the landfill and drys up during
part of the year These streams flow into the Saugatucket River
which flows throughout the year and is larger than the west and
central streams combined
11
The USGS Groundwater Map (18) was initially consulted to proviae
information on the ground-water flow patterns (Fig 5) and the
geology of tne area (Fig 6) The surficial geology borings and the
vertical geologic cross-section at the base of the study area
indicate shallow water table and bedrocic and a nearly constant
saturated thickness (18) Boring logs at the W well ana a point
approximately 150 feet south of it indicate glacial outwasn material
which is primarily sana with a trace of gravel over bedrock at a
depth of approximately 33 feet Borings at the east landfill area N
and S monitoring wells indicate the same aquifer material
(Appendix B)
The ground-water map developed by Hahn is taken as
representative of conditions existing prior to the excavation of the
I l andfill (18) This indicates water-table contour lines that run in i
a general northeasterly direction This means tnat flow was
originally in a southeasterly direction However contamination of
domestic supply wells on the west side of Rose Hill Road has
occurred (Fig 3) strongly suggesting that the original flow pattern
has been altered by the excavation to the west of Rose Hill Road and
the landfill to the east of it Domestic supply wells were formerly
located directly to the west of Rose Hill Road but were aoandoned
when they became contaminated from landfill leachate New wells
were located to the south and west away from the contaminant plume
of tne landfill In addition a well located at the northeastern
corner of the landfill was contaminated and a replacement located to
the east of Us former location on tne opposite side of the central
12
Legend scale 124000
mdash-40 mdashground-water contour elevation
Fig 5 Ground-Water Map
13
Legend feet
TILL
Fig 6 Geology Background Map
14
stream This second wel 1 also became contaminated Domestic supply
wells located near tne northwestern corner of tne landfill and
approximately 300 feet south of it nave remained uncontaminated
These well locations serve as an indication of tne extent of the
landfill contamination which is largely dependent on the groundwater
flow patterns To furtner investigate this problem and provide
substantial information on which to base the geohydrologic analysis
field studies of the area were conducted
15
Field Studies ana Procedures
A map of the lanafill and an aerial pnotograph of the area were
obtained A tracing of these maps superimposed upon another
delineates stream landfill and monitor well locations (Fig 2)
The field investigation concentrated on the west landfill area ana
its aajoining streams ana monitor wells The east landfill area and
the three monitor wells in that area are induced in the latter
phase of the study in oraer to expand the model area
A traverse which establishea tne monitor well elevations was run
using a Carl Zeiss level These were originally sitea in by the
town of South Kingstown using a local USGS reference datum number 40
(18) The wells of known elevations then served as benchmarks for
referencing adjacent stream elevations This in combination with
the depth to water table measurements at each well enables tne
water-table surface geometry of the area to oe visualized
Water-table measurements of the west landfills wells were recordea
over a ten month period to record fluctuations (Fig 7 Table 1)
The east landfill areas wells were monitored for a five month
period Using a given water-table condition a ground-water map was
developea of the area (Fig 4) This indicates an outflow from
the landfill primarily in a southeasterly direction and partially
in a southwesterly direction
Additional bedrock and water-table information was ootainea by a
seismic refraction survey at several locations along the landfill
perimeter A Bison Model lb70C Signal Enhancement Seismograpn was
used to maxe the surveys Lines were run (to a length of kOO feet)
16
17
w s p bdquo S bdquo s S S a laquolaquo _
s 2 8
V
r bdquo
3 s a
-R s
S
S 3
t
raquobullraquo
S
5
K
r
~
3
K
pound
7
S
bdquo3
C 5 S
shy raquo S s
1 3 s 3 2 5 ^ bull
5 m
s o
^ 3
raquo
--
R bull 5
s pound J O s
5 a 3 7 3 m
5 s a ^
iraquo a s rlaquo
M ^
^ c o 2 5 s 3 a S R
rd 3 y a O =J
^ bdquo
JJ s s 3 bull ~ I
~ s 5 3 a s a
(Ogt (U
2
-t =
r s s in
5 y
a s
5
3
s
5 a
^ a
3 a 51 a bullbull
sj 5 Ml
3 a bull
s raquo
a
0)
0
^ mdash
a j -
-3
C
g S
S
bull a
-
~ 3 o
2 s s 3 a bdquo s s $ Al s
(1) = $ s 3
S
c a a
3 e 5 s N s S a - 3 = s s a 5
a s s - 3 S shy
4
0
a s
bdquo tfH
bdquo
3 a
bdquo
s a
e bullfl s i s s a s a
3 nt
s s 3
g laquo s3 a
~ J s 2 a s o s S s 3 a a j laquo s o s
3 bull laquobull
2 a 7 3 a 3 a ^2
s mdash 5i o
bull bull
mdash
3 o
ss a
fc mdash
3 1-sect m ishy n
18
in both directions to provide a check and permit accurate estimates
of the depth to bedrockThe seismic results allow approximate
interpretations of the depth to the water table and bedrocK thus
permitting an estimation of the saturated thickness Ground
elevations at the location of the seismic surveys were determined
from a topographical map and field siting From this information
water table ana bedrock elevations estimates were made Bedrock
contours are listed in Fig 8 In addition a table which
summarizes the seismic refraction results for the unsaturated
saturated and bedrock layers velocities and depths at each survey
location is presented in Table 2
Scream gauging stations were established on the two streams
bordering the west landfill (Fig 9) Three stations were placed on
the central stream These provide information on the influent or
effluent condition of ground-water flow in the upper sections of the
stream and ground-water baseflow from an area adjacent to the
landfill into the stream (Table 3)
The stream gauging stations used were 90deg V-notch weirs The
weirs located in the SE and SW positions were placed in the
streamoea with a liner of plastic upstream to minimize underflow
The weirs located in the NW and E positions were cut to fit in
recesses of concrete culvert pipes Concrete plywooa interfaces
were coated with roofing cement to minimize bypass flow Upstream
water pressure and a snug fit hold the plywood sections in place
All weirs were implaceo according to AigtTM reouirements and flowrates
calculated using the standard 90deg V-notch formula (3)
19
N
seepage West observat ion Landfill hole
Area
Legend landfill limit excavat ion limit
copyWNWNEECSESC monitoring well locations
= = = unimproved road -- WNES-number
seismic refraction locations
-40shy approximate bedrock contpur elevation
feet
Fig8 Seismte Survey Location
20
c ^-^ c4j ^laquoc in -=r 3shyjj bull pn f- 4-gt bull in in OjJ bull bull a jo bull bull O JJ
co CM o on on CO CM CTNVO VO co CM o on on Q gt_x rH oj on a oj on a - rH oner
rmdash on sr i i
M z Z
gt gt gt
X-N CO laquomdashv CO CO bull igt gt bull
1 gt fc^gtgt bullbull ^ ^ ^
C 4-gt O t igt O J- 4J O H m o o o 3 bullH CO O rH in 3 bullH co vo o in 3 ~ 1 i-k -i ^trade fj rj ui ij o CO o n o rH =r co o n vo vo vo co o bullv O O O
O raquo On-3 rH O -bull- rH ON in _ IH in oj - rH bull rH VO OrH bull rH On ON pH d)u CO -UCO 4J OJ CO 4-gt gt
C mdashbull gt CM gt CM H-l O CO
v- ^^ N C 0
bull0 N CO
4-5 -0 _c^gt in in CO CO
C x~ c -^ t-oo in i 4J j_gt 41 4J bull 9 bull bull 4J bull
o j ON O O 3 (0 O4J O ON ON QJJ t~-^3- OJ 4-gt L
CO CM trade CO CM rH rH OJ co CM oj on Q ^ _ CO 3~Q-- n 45 Q mdash OJ OJ OJ C (0
1 11 3 nZ 2CO
gti gt gt CO CO CO ^-x m -s CO
rH rH ^ ro^^ bull gt bull ^ igt gt bullgt gtgt bull r O -Q 4Ji JJ O 5- JJ O pound- ^ O 4) oj o on (0 CO
3 bullH CJ O O in 3 bullH CO Cmdash VO on 3 pound-laquo H CO o n in inco co o n ma- r co g^ 5sect^ o
o rH on oj O bull- rH ONCO L O_ rH OJ VO M
rH bull rH =t rH bull - OJ T CO CO M CO 4-gt rH CO -U rH CO 4-) s
uits
CO 4-gt 4-5 T3 gt CM gt CM gt CM cc CO CO CO
3 3gt oa tlp^ CO O CM O gt 4J O 40 i 3 r+ k C pound JS
CO pound
^^ s -bullgt cmdash on poundZ VO CTI trx 4J 4J 4J
) bull bull bull Q Q Q Q4J 3shyc O-JJ CTgt OJ OJ Q-IJ inco on CO CO CO o co CM oj on co CM oj on co CM on
Q Q QON^ Q bullH Q^
rH rH 4J rH
O bullraquo L Z bull CO CO CO
i gtgt rH oj on gt tgtshyCM ^ cO^-s CO ~ CO
CO CO J X fc^_ bull^gt bullgtgt bull gt gtgt bull gt CO
j_ jJ O pound- Jj -P O Li deg =fObullH co on f- ^ 3bullH CO CO O in 3bullH CO
g^ -^2
poundsect HO
eis
mic
3 CO in in in in in in co o n co o n
o -^ r oj in O rHCO CO rH bullrH bull rH =T OrH bull rH OJ f-CO 4J bull- CO 4J rH O0) J-)
gt CM gt CM gt CM 4J
CO N_^ m^
bull OJ
t t poundshyCO CO CO CO rH J3 gt r-t oj on gt r-i oj on gt gt r n o j o n
lto co lto CO T bull ii-4 laquomdash bullmdashH
bullo CO L L 0)
CM CO cc
21
N
545-594
seepage observation
hole West Landfill
0NE I47-509
Area
Weir 45
i487-531
0 EC Al3-467
Legend bullmdash landfill limit -bull---excavation limit r-s stream
copy WNWNEECSESCSEN monitoring well locations
= = = unimproved road
Weir location and elevation
feet
Fig 9 Weir Locations and Wate r Level Ranges
22
JT NO
S shy S
O
bull ry m
oa
NO
(M raquo 1 03 or NO m
JT O O raquo
O NO 03 (j
PW tn in ^4 fraquo
m CN) f O O (M Oj
mdashraquo 3 M
s cshy -raquoraquo
o in in ^
rjO
laquobull NO ON
o bull-lt ^
H fy (NJ
tjgt
1 4 03 O
o
o
03 CM
in0
0
7 raquo
9gt
IM i iev NO
i in
i ru
i 0 rsi -or^
sO NO
CO O
03 raquo
1 O3
pound o ro CNJ
03
tn B OJ
o 03
m oi
NO
(M
r
(M
CO i M 03
m N ltn ~+ ltM -
QJrH
O M O ^ ^r-
oo m
8 a
m
^ NO
8 fNl
rshy03n
m - in
o laquoO
bull3 as m o 03 03 4
i O
i ^
shy
O
ltM bull^
ON f tn H 1 4 raquo4 i-4 H P-t
^^ lt-l
r-laquo
^ 1 1 1 1
pound raquoraquo O)t o gtz
bull bull ltbull
lt2
1 pound OJ
3 oi g bull
pound
1 pound laquolt bull
3 bull o a
pound
5 laquo15
f bull 3 Jl s
5bull 1 5
23
A field study to determine the infiltration capacity of a
section of tne landfill topcover was conaucted A modified version
of a double ring infiltrometer was used to study infiltration rates
(4) The cylinder diameters useo in this study were 8 inches and 18
inches A constant head of 6 in was maintained in the
infiltrometer and rates of infiltration were determined Tnese
results and an analysis of surface infiltration into the landfill
are included in tne analysis and discussion section
Specific conductance levels in the monitoring wells in the
streams bordering the landfill and at observation holes near the
landfill were measured (Fig 10) This is a good indication of the
mineralization of water (39) Specific conductances were measured
intermittently over the ten month period to develop a picture of the
extent and degree of contamination in the wells (Fig 11 Taole4j
and in the surface contamination monitoring locations (Fig 11
Table 5) A comparative standardization of the Beckman (short and
long probes) and YSI specific conductances is in Appendix C
A surface electrical sounding using the Schlumberger array was
conducted adjacent to Rose Hill Road at the R-l location (Fig 12)
in an attempt to delineate the vertical extent of the contamination
zone Well W was used as a centerpoint and a reference for
water-table depth pore water conductivity and depth to bedrock A
Schlumberger array electrical resistivity sounding was also
conducted in an uncontaminated area at tne R-2 location (Fig 12) to
provide a comparison background interpretation A seismic
refraction survey N-4 was conducted at the same location (Fig 8J to
24
N
excavat ion
Seepage West observat ion Landfill hole
Area
Stream 1 Seasonal observation 0 EC
hole
East Stream2
Legend sw Weir landfill limit j--1--^ excavation limit
copyWNWNEECSESC monitoring well locations
== unimproved road
feet
Fig 10 Surface Contamination Monitoring Locations
25
8000T
7000
O bull U) W6000
Legend
0 sc A NE O W
A SE O N W
a EC
1 O N D J F M M
Time months Flg11 Flucuatlon In Specific Conductance in Wells
26
Table 4 Specific Conductances in Wells (pmhoscm at 25degC)
West East Landfill Landfill
Date NW NE EG SE W SC N E S
81581 851 938 236 2356
102981 171 3268
11381 3268
111081 304 988 1100 258 3800
111481 426 2736 1216 186 4560
111781 304 3610 433 389 4560
121981 380 1406 129 103 380
1982 160 152
31582 274 760 1064 61 334 8000+ 182 53 84
52182 450 1500 1125 112 712 8000+ 175 255 150
52282 425 1320 1200 110 850 180 320 170
27
O
ct c r i c o o o o o c M o m o in CO CM unp^
3bull t- fmdash o^ co tmdash vo co in co cmdash co in a
bull bull1 1-1 trade4 rH rH^ CO 4)2
~ plusmn4J o O CM ^_
o n CO vO J oraquo 0C0M
cu rH rH rH rH rHin tmdash
3 iCM 4J
^j CO CO
E O0 ltU -H n o c E
See
pag
se
rva
t
rH O in 0 0 O O 0
O o x rH Cmdash
0 0n
cu rH mdash O tmdash X o o o o c o o o o r H r H i n o i n i n o O
bull L in oo co oo oo o cy cr o rH CM o cr ONc fcJ bullH on en m m rn c^n rH rH rH0 pound CO 3 CO
t CM0gt s o o o in rA n ^o oo in tmdash oo 0gt zr =r a- JT JT$_
T)C CO
~ E CO ^ _bdquo ltu CO g r H r n c n i n o o r H r H
vgtO ^D O ^^ ^O CO ^^ ^^ JJ 2 4) rH rHCO t
c CO
CO c 9) rH 0
CO -^ C c CO ltuo famp O trade t iH
0
bullo co n ^
oS
o ^^ bullH m
i co rn O CQ O1 CO CO 4) c2Q 3
CO
mdash^ bull cmdash CMin 1 gt rH vO vO O CTgt CO
s CTgt CO OO Ogt Craquo- tmdash cu O CO rH z 0
bull_bulllaquo
H bull L o in r in o oo in 3 rfy ff^ tir f^ CO C^~
4)bull
Z 3
^ ^ ^ ^ H r H r H r H r H rH r H C O r H C O a O C O a O a O C O C O r H i H r H CO OO - gt 0 0 ^ - gt ^ raquo - ^ ^ 1 - gt ~ gt - C O C O O O
U ^ raquo ^ - ~ raquo O ^ ^ O t ~ C O r H - r r ^ - ^ ^ JJ r H C M v O r H r H r H r H r H C M C M r H i n c r gt rH CO CM gt laquolaquo - - -^ bullmdash mdash bullraquoraquobullgt -v -v ^^
~ v O r H r H r H r H r H r H r H r H lt M C M C M CM O O r H r H r H r H r H r H r H r H r H r H r H r H rH
in rH cmdash
CO vo
CO vO
41 rH CO
CTgt rH raquo CM rH
cn CO
o 0 rn
CO cmdash
tmdash fshy
CM ao
iT rH
m
ogt ao
O o vO
CO t-
tmdash Cmdash
CM CO
rH CM
I
rH CT
O vO in
CTgt
in c^
CM ao
CM CM
in
-
bull
CO bO C bullH T3
cy ~
_
CJ E 3 ^ n c bullH
1-1
CO
^H
28
excavation
West Landfill
Area
Legend bullmdash landfill limit -bullbull--bullexcavation limit r~~s stream
copy WNWNEECSESCSEN monitoring well locations
= == unimproved road
electrical resistivity sounding
feet Fig12 Electrical Resistivity Sounding Location
L
29
allow estimates of depth to water table and bedrocic to be made
Soundings were carried out to 500 foot electrode spacings to insure
that hredrock was penetrated and to facilitate interpretation These
results and a discussion of the soundings interpretation are
included in the analysis and discussion section Schlumoerger
resistivity soundings were made using a Soiltest R-bO unit
30
Model Development
The USGS Iterative Digital Model for Aauifer Evaluation was
usea to develop steady state flow models of the study area (43) A
flow chart of the computer model and a brief explanation of the
subroutines usea is presented in Appendix D The stream locations
elevations and aauiferlandfil1 geometry and hydraulic properties
were input to the model to compute head values at each 200 foot
grid spacing node (Fig 13) The input data which is for the
existing excavation and landfill conditon is listed in Appendix E
The head values that are computed at each grid space are in turn
loaded into the CalComp plotting routine (44) where a grid spacing
is setup with the computed head values at each node The contouring
program linearly interpolates between these head values and
generates a contour map The computer simulated ground-water
contour map for the excavation and landfill is presented in Fig
14
The streams in the model generally serve as controlling boundary
conditions When using computer simulated geohydrologic models of
an area choosing the boundary conditions for the model that are the
same as prevailing conditions in the field is a critical step in
model development Extending the models boundaries to areas in the
field that have a minimum influx of ground-water across them
simplifies the proolem of calculating fluxes from outside the model
area The eastern boundary is bordered by glacial till which has a
low hydraulic conductivity estimated to be 67 ftday(2) This
contrasts to the high hydraulic conductivity of glacial outwash that
makes up the model area of approximately 107 ftday(3036j
31 N
o 9
bullO O
32
33
The Saugatucket River serves as the controlling boundary on the
east A small drainage area directly to the east of it provides a
minimal influx
Beyond the moaels northern boundary the glacial outwash valley
extends to the base of a till covered h i l l on the western half ana
on the eastern side extends along the Saugatucket stream Due to
the relatively large drainage area that lies upgradient from the
northern boundary a recharge flux eduivalent to 10 inyr over the
drainage area on the till hill and outwash area north of the model
area was input as underflow (Fig Ib) Part of this was input at
each northern boundary node Till has a lower infiltration capacity
than outwash so more of the precipitation w i l l be transmitted as
overland runoff resulting in a lower ground-water baseflow The 10
inyr of recharge that results in a ground-water inflow from the
combined till and outwash region represents an estimate that is
smaller than the 14 inyr recharge for glacial outwash areas in
Rhode Island (25)
The glacial outwash valley extends beyond the western boundary
No significant ground-water recharge flux was estimated at this
boundary A relatively low ground-water gradient exists to the west
of this which does not provide a significant flux across this
boundary Tne southern boundary is basically the outflow region for
the area and therefore would not reauire any ground-water flux into
the moael area across this boundary This boundary was set south of
the point that the streams in the model merge together Therefore
the streams which lie to the north of it are the controlling
34
scale 124000
Fig 15 Northern Drainage Area
35
boundary conditions The flux out of the downgradient outflow
region approximately eauals the influx from precipitation recharge
and boundary influxes
When tne stream configuration in the moael area are reviewed it
can be seen that they comprise a large portion of the boundary
area The screams can act as sources or sinks for water in the
model thus providing to and removing water from the aquifer The
leakance option was used in the model which provides for a confining
bed and aouifer area beneath the stream to be input
The leakance is defined as the hydraulic conductance of the
streambed divided by the streambed thickness which in this case is
taken as 1 foot The leakance value at each streambed node
restricts the flow between the aduifer and the stream The
streambed hydraulic conductivity is typically 01 the value of tne
hydraulic conductivity of the aduifer (717) The value 107
ftday was used for a streambed conductivity based on a value of
107 ftday for the aquifer The aduifer and stream hydraulic
inputoutput exchange at eacn node is calculated by initially
finding the difference between the initial field stream head
elevations and the computed head elevation values at the
corresponding nodes This head value is then multiplied by the
(Leakance value at each node) x (stream area of each node)
Therefore if the aduifer head was lower than the stream head the
stream would act as a source of water for the aquifer and vice
versa
36
Tne leaxance input at each stream node is the ratio of the
actual field streambed area in each node to the area of each node
which is 200 ft x 200 ft = 4 x 104 ft2 The west
excavations stream width is approximately 3 ft central 4 ft and
east 5 ft Therefore if tne west stream traverses the node
directly without meandering it presents a leakance of 3 ft x 200
ft4 x 104 ft = 015 Leakance and streamhead values were
input at each node to set up the stream flow parameters in the
models
A recharge value of 14 inyr over the entire area was input at
each node This represents a value of precipitation that is
transmuted into tne ground-water rather than being directly
evaporated evapotranspired through plants or overland flow
runoff The precipitation recharge flow from the stream into the
aauifer and boundary fluxes provide the model witn input flow
parameters
From analyzing the available information it was determined that
the study area lies within a glacial outwash area with a relatively
shallow bedrock The seismic survey around the landfill generally
indicates a depth to bedrock below the land surface of approximately
29-43 ft with corresponding saturated thicknesses of 19-33 ft as
seen in Table 2 This agrees with borings from tne USGS groundwater
map in the stuuy area (18j The seismic survey was run at a low
water table condition which was several feet below the high water
table level (Fig 9)
37
High water-table saturated thicknesses were used to develop
model parameters For the purpose of this model study the saturated
thickness was set at 30 ft except in the vicinity of well W where
there is a bedrock high (Fig 8) At this location a high water
table saturateo tnicxness of 8 ft was estimated In tne vicinity
the seismic survey was conducted the bedrock elevation at this
location is the highest and the saturated thickness the least Tnis
can be seen by an east-west cross section of tne landfill (Fig 16
The boring log for well W indicates a sand trace gravel outwash
material (Appendix B) Boring logs at the eastern landfill area N
and E indicate similar material On this basis the hydraulic
conductivity was estimated at 107 ftday (3036) Witn the
exception of the landfill and the bedrock hign areas the
transmissivity values were set at 107 ftday x 30 ft = 3210
fto day From the literature the hydraulic conductivity of the
landfill material was estimated at I ftday (19) The
transmissivity of the landfill material in tne nortnern section was
estimatea at 1 ftday x 30 ft = 30 ft^day or approximately two
orders of magnitude lower than the outwash In tne landfills
southern section the original excavation was not as deep as in the
northern parts The landfill material was estimated to makeup only
one half tne saturated depth the remainder being the original
glacial outwash material (Fig 17) Therefore the transmissivity
at the southern end was estimated at 15 ft x 107 ftday + lb ft x
1 ftday = 1620 ft^day These values were graded into the 30
ft^day values at the landfills northern halfway point These
38
were input as transmissivity values to the model at their respective
locations This model did not use the water taole option so
water-table fluctuations did not affect the transmissivities
39
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Model Calibration
A simulation was run using the initial estimates of stream
parameters aquifer and landfill hydraulic conductivities
transmissivities boundary and recharge conditions to approximate
water taole conditions in tne fiela Initially the existing
condition of the excavation area to tne west of Rose Hill Road and
the landfill to tne east were modeled in order to calibrate the
model to current field conditions as shown on Fig 4 The simulated
well values (Fig 14) fall within tne range of field values (Fig
9) The resulting contours also provide an approximate matcn This
can be seen by comparing Fig 4 with Fig 14 An additional check
was to match the flow loss and gain in the streams between tne weirs
in the central stream which w i l l be discussed later The
simulated flow value from the excavation drainage stream is the same
as that measured at the SW weir location Having calibrated the
model by approximately matching well water levels nead contours
and scream flow values different field conditions and possible
remedial measures can be simulated
When the model grid was laid out over the study area as viewed on
Fig 13 the stream configuration rarely traversed the grid nodes near
their central axis When the stream locations were input to the
computer the information was documented as crossing the central axis
of the grid nodes The result of this is a slight aberration when
the actual stream configuration is laid over the computer graphics
head contour output The streams dont always cross the groundshy
water contour at the logical location Rather than modifying the
actual stream configuration to adjust then to the computer output
their actual locations are presented
42
Simulations
i The primary focus of the computer modeling is to analyze flow
patterns under changing conaitions in the near vicinity of tne raquo
landfill The study areas overall flow patterns as they exist
today are first presented in order to realize the lateral east-west
head contour lines between the stream that directly borders the
landfill on the east side and the SaugatucKet stream (Fig 14)
This indicates a general southerly flow direction in that area As
different conditions are modeled these contours generally maintain
their east-west orientation In order to facilitate interpretation
of flow patterns in the near vicinity of the landfill flow patterns
to the west of the stream that borders the east side of the landfill
r are presented in the subseauent models
L- Natural Conditions
The results of modeling the original natural conditions are
shown in Fig 18 The excavation and stream to tne west of Rose
Hill Road and tne landfill did not exist in this simulation The
southwestern boundary consists of a drainage stream that was
delineated using an aerial photograph and stream elevations were set
using the topographical map The USGS ground-water map (18) was
used to estimate head values between the west excavation and north
streams These were input to the model as constant heads on the
models western boundary The resulting simulation generally matches
the southeasterly flow direction that is indicated on the
ground-water map (Fig 5)
A3
Legend
x-^- stream 400 = = = unimproved road
I f ee t
Fig 18 Natural Conditions
44
Excavation Without Landfill
The condition of the excavation to the west of Rose Hill Road
with its resultant drainage stream without the landfill was modeled
next (Fig 19) The extent of the excavation ana the location of
the new drainage stream were delineated using the aerial
photograph The west stream elevations were sited in the field and
used in the model The concept of a confining streamoed layer was
excluded in tne excavation drainage stream under the concept tnat no
significant organic layer had been built up within the 25 year
period that the excavation had been initiated Head values between
the west and north stream boundaries were interpolated and input as
constant head values on the northwestern boundary The west
excavation drainage stream creates a condition that alters the
natural ground-water flow patterns by creating a more southerly flow
condition the drainage stream providing a more immediate surface
outflow in that area
Landfill Without Excavation
The hypothetical case of a landfill without the excavation was
modeled next (Fig 20) The low hydraulic conductivity zone of the
landfill changes the natural flow conditions and creates noticeable
mounding This is evidenced by the decreased spacing of the head
contour lines and deviation from the lateral contour lines of the
natural conditions and higher head values (Fig 21)
45
Legend
excava t i on s t ream
400 unimproved road
f e e t
Fig19 Excavat ion without Landfill
46
Legend
landfill limit
bull - s t ream 400 copy WNWNEECSESC
monitoring well locations f ee t bullbull-bull=bull unimproved road
Fig 20 Landfill without Excavation
1
oin CM
bull
m u
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oO
bullo 9
bullo 9
o rf o o CO 1
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47
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bulla caj
CM
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48
Landfill ana Excavation
The condition of tne existing landfill and the excavation with
the dam is the next condition modeled (Fig 22) The ground-water
elevations used to calibrate tne model correspond to an actual high
water table condition Between the NVJ and pound weir a streamflow loss
of approximately 102 gpm occurs aoout 60 percent of this flow is
lost at the dam site which maintains a head of b-6 feet over an area
of approximately 1800 feet^ This approximates a field value of
1144 gpm influent to the aduifer between the NW and E weir on ]2
December 1981 (Table 3) From the E weir to the SE weir a net
increase in flow occurred of 74 gpm which corresponds to field
increase of b62 gpm
The surface runoff from tne landfill flows primarily toward tne
eastern side of the landfill Increases in water-table elevations
on the eastern side after heavy rains such as the 11 November 1981
storm indicates that this runoff increases outflow gradients to the
stream and therefore increases streamflow Surface runoff input is
not modeled which explains in part why field stream inflow values
are slightly higher than model predictions especially for periods
after a storm has occurred The flow from the SW weir located at
the southern end of the excavation represents drainage outflows from
that area The net flow calculated in the model was 140 gpm
which approximates field conditions of 1642 gpm on
December 9 1981
49
d f l f reg N E
shy
Legend
landfill limit -bullgt-bullgt- excavation ^-N_X- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road
-40mdash approximate groundwater contour
400
feet
Fig 22 Landfill and Excavation with Dam
50
The modeled flow patterns suggest how the various contamination
zones around the landfill have developed to their present state
They indicate a flow to both the southeast and southwest on their
respective sides of the groundwater divide Evidence of a
southwesterly contaminant flow is presented when the continued high
specific conductance contaminant level in tne observation seepage
hole is realized (Table 5 ) In addition the specific conductance
increase in the west excavation stream is evidence of an influent
contamination flow
Contamination flow to the eastern and southeastern side of the
landfill is obvious High specific conductance levels in the wells
on the eastern side (Table 4 ) a specific conductance increase
between the E and SE weirs (Table 5 ) and contamination in the NE
domestic supply well (Fig 3) present conclusive evidence of
contamination to the eastern side of the landfill
An anamalous condition that exists is a domestic supply well
located approximately 300 feet due south of the landfill remains
uncontaminated (Fig 3) Flow patterns indicate that contamination
would be transported from the landfill south to this area
(Fig 14) One explanation is that a pocket of clay at the southern
end of the landfill area was discovered in the original excavation
for the landfill (lt6) This evidently prevents leachate from
reaching this wells radius of influence
51
Summer Conaitlon
As described earlier during dry months of the year the stream
that normally borders the northern and eastern side of the lanafill
may dry up as far as a point southeast of the E well Tnis
condition existed from the 15 August 1981 to the 27 October 1981
period when streamflow commenced in the northern part of the stream
yet did not overflow the north dam until 17 November 1981 This
created the present day continuous flow condition throughout the
stream These summer conditions were modeled by removing the stream
above the aforementioned location while other conditions remained
the same (Fig 23) Summer condition well water levels listed in the
model generally match field low water table conditions (Fig 9)
Because there is no stream upgradient from the landfill to provide a
stream head and infiltration through the streambed groundwater
runoff from the area north of the lanafill is the controlling flow
input In these moaels an average recharge of 14 inyr was used
which represents a yearly average The summer recnarge conditions
are prooably lower given the effects of decreased rainfall and
increased evapotranspiration during the summer months A domestic
supply well whicn exists northeast of the landfill (Fig 3) nas a
greater potential to be contaminated from the lanafill at tnis time
than when the stream is flowing Flow patterns from the landfill
are such that during an upper stream no-flow condition groundwater
flow patterns are more in an easterly direction than in a
southeasterly direction The stream would act as a source of
infiltrated water upgradient from tne landfill and provide a
52
I ^N gt i I i j i -r- -bull- bullr -T- t- -r- i- TJ JV
bullbullT laquo ^ O - laquo bdquo xi cshy
H r^~ I -~- --^ X- = mdash x^ N
^--^ A bull O^NW -v - gt-bull Ni i I _____mdash - bull laquo l - mdashmdash 1 deg I ^ltv I C
I reg NE A
Js bull vbull A ~ - v T gt- ^ ix - N
-5Z- | N TfS lV I -bull bull iA i gt gt I ^ bullr-Ky L bull 1 _- copy]wgt-- - bull- mdash - - shy
= r Y ~mdash ltmdashA A
^^-lt A _ - - - - bull Hmdash - reg EC x ^-mdash mdash I ---mdash_mdash -t-V-^N - y
I- -bull - r x i X
V ^ 7 I -v (^~~^^r ^^^
sc Emdash-bull vV JI - - - ~ r )N y- -
X - bull r bulllt
^bull^ y y Jlaquo^ - -lt shy
T s^ lt^ ^ +^-b (
X
Legend
landfill limit j-j-bullraquobull excavat ion gt^ -x- s t ream
reg WNWNEECSESC monitoring well locat ions
= == unimproved road fee t
Fig 23 Summer Condition
400
53
constant head across tne northern section of the landfill This
would tend to orient the flow in a more southerly aowngradient
direction In addition the stream which flows adjacent to the
northeastern well could provide a source of infiltrated clean water
to it which would minimize the possible contamination from landfill
leachate
Without Dam
During tne spring scream flow condition the dam failure which
occurred between the 15 March 1982 ana 9 April 1982 monitoring
periods decreased flow to the aauifer and landfill This eliminated
the 5-6 foot head difference over a 19000 ft^ area which had
created a larger area and elevation head for infiltration to occur
The condition without the dam was modeled by reducing the area
encompassed by the dam to a 4 foot wide stream channel thus
reducing the leakance value at that node (Fig 24) The flow change
from the stream to the aduifer between the NW weir and E weir
reduced the model flow loss to 50 gpm Tnis corresponds to the 9
April 1982 monitoring period which indicates a 30 gpm loss
As compared to the previous flow loss in the upper stream
sections to the aauifer the 21 April 1982 and 22 May 1982
measurements between the NW and E weirs indicate a flow gain The
streamflow conditions have changed from an influent
stream-to-aauifer condition to an effluent aduifer-to-stream
condition that increases flow downstream
54
Legend
landfill limit j--i--i- excava t ion x-gtmdash^- stream 400
copy WNWNEECSESC monitoring well locations
= == unimproved road f e e t
Fig 24 Landfill and Excavation without Dam
55
Analysis and Discussion
In order to fully understand flow patterns and Quantify leachate
outflows at the landfill it is necessary to arrive at an estimate
of flow inputs from precipitation ana upgradient sources In the
following analysis it will be demonstrated that the rainfall input
to the landfill is the factor which controls leachate generation A
calculation using the H inyr recharge over the area of the
landfill was made to estimate the leachate outflow due to rainfall
infiltration An estimated 134 gpm is generated from the entire
landfill area Simulation of the existing conditions (Fig 24)
indicates a groundwater divide in the landfill is located
approximately at the western third Therefore approximately 23 of
the generated leachate flows to the eastern side of the landfill or
9 gpm The effect of the flow input from the upgradient stream is
evident when tne summer condition witnout the stream is viewed
(Fig 23) Without the stream to infiltrate the landfill and the
recharge and northern boundary condition as the flow inputs the
head at the northern end of the landfill drops about 5 feet from its
previous value A flow pattern from the north central part of the
landfill to the eastern side indicates a 12 feet head difference
with recharge - but with the upgradient stream a 16 foot head
difference occurs Considering the transmissivity change the
stream would increase the leacnate outflow from the landfill
approximately 43 under a low water table stream influent condition
to the aauifer This would increase leachate outflow to the east
side to approximately 129 gpm This value approximates the
56
outflow at the SE weir location during the summer monitoring period
when the upper stream was not flowing (Table 3) The outflow from
the western third of the landfill whicn lies to the west of the
ground-water divide would be approximately 63 gpm
Realizing the importance of infiltration to tne landfill as a
major influence on the generation of leachate an analysis of this
w i ll be discussed An estimate of infiltration was made using the
precipitation recora for October ana November (Appendix A) During
this time period a minimum of direct evaporation ana
evapotranspiration occured and the grouna is not yet frozen The
top cover over the lanafill is generally 05 ft to 2 ft of local
sandy soil and subsoil availability determined what was used The
top of the landfill is at an elevation of 92 ft as compared to the
ground surface at well W which is at an elevation of 76 ft
(Fig 25) This compares to the well W water level which is at an
elevation of approximately 52 ft This creates a long path for
infiltration through the unsaturated zone The topcover generally
slopes eastwara at a grade of 2-5 The west side maintains a
relatively steep slope of 10-15 ft drop within 50 ft ana the north
and eastern slopes have a more gentle slope of approximately 10 ft
within 100 ft distance An unlined surface arainage swale channels
surface runoff from the northern section of the landfill past the
NE well to the eastern side ana low area in the vicinity of the E
well This has a drainage swale to an area near the stream but
doesnt directly connect to tne stream A poorly graaed drainage
swale exists on the landfills left side The landfill material has
57
excavation
seepage observation ^
hole
Legend bullmdash landfill limit -^--excavation limit r^s- stream
copy WNWNEECSeSCSEN monitoring well locations
--- unimproved road O location of amp Inf i l t rometers O
feet
Fig 25 Infi ltrometer Locat ion and Drainage Feature
58
been placed in 10-12 ft cells and covered with 1 ft of soil at the
end of each day The material has settled differentially creating
areas for depression storage
An estimate of the percentage of precipitation that infiltrates
the landfill was made from precipitation records recorded well
elevations and an estimated specific yield for the landfill
material The volume of water that infiltrated should eaual tne
specific yield multiplied by the well water level rise Several
recharge periods were studied using this relationship Once the
percentage of precipitation that has infiltrated is determined the
percentage that is translated into runoff is simply the remaining
percentage if evaporation is neglected
From the literature for a slightly inclined slope of 2-5
typical runoff coefficients range from 10-20 in either sandy or
heavy soil (16) The landfill cover is generally sloping to the
east which creates a long path (approximately 400 ft) before the
runoff reaches the steeper slope on the eastern side of the landfill
of 15-20 The long drainage distance creates a greater time for
rainfall to infiltrate Another consideration is the actual
capacity of the soil to conauct water into the soil which was tested
in the field using double ring infiltrometers An average initial
percolation of 8 mmhr the first hour and a subseauent rate of b
mmhr occurred (Fig 26) The 8 mmhr rate compares well with
other sandy soil infiltration rates (14) Therefore if the
intensity of the rainfall exceeded a 5 mmhr rate for several hours
59
CO + 09 o
E o
CO
o Z pound C
O
C9
o DC
CO
CD CM
ogt CO N- to -4 CO CM
jq tuu i U O | raquo B J J | | J U |
60
on a poorly drained surface the additional rainfall would be
translated into runoff because the soils infiltration capacity had
been exceeded
The initial 8 mmhr infiltration rate was due to the pore spaces
in the sandy soil being filled and the subsequent 5 mmhr rate was
percolation into the low permeability landfill material The tests
were conducted in November assuming a minimal evapotranspiration
and the field capacity of the sandy soil had been maintainea
The W well was used as representative of the water elevation
changes in the landfill because it is directly adjacent to the
landfill 900 ft distant from the upgradient stream This minimizes
the effect of infiltration from the stream and maintains a high
contaminant level During periods of high runoff conditions excess
surface water ponded in a poorly graded drainage swale on the west
side and directly adjacent to the landfill This influenced the W
well at a time the contamination level dropped (Fig 11) Before
this occurence in mid-December the rise of the W well closely
matches that of the SC well and a background well SK6 which is
located outside the study area (Fig 7) Therefore it was analyzed
as a valia indication of the water level rise during the mid-October
to mid-December period The monitoring of the SC well was
intermittent due to inaccessaoility because of 10 ft extensions
being placed on the well as the refuse was being filled in arouna it
61
A high rainfall period from 14 November 1981 to 1 December 1981
was chosen for the initial study period The effects of
evapotranspiration were neglected due to the cool temperatures
experienced at this time Therefore it was assumed that the field
capacity haa been reachea and tnat any additional input to tne
unsaturated zone would result in direct percolation to tne saturated
zone During the time period 14 November 1981 to 22 November 1981
029 ft of rainfall fell and the well W rose from 488 ft to 493
ft - a 05 ft increase During the next 8 day period there was no
precipitation yet the W well continued to rise to 4972 - a 042 ft
increase The slow percolation of water through the landfill
material would account for the latent rise in the well water level
From previous reports a specific yield for refuse was estimated to
be 028 (1920) This value is dependent on the original compaction
of tne material age and resulting consolidation
During the 14 November 1981 to 1 December 1981 period 029 ft
of rain fell and the well increased 092 ft The following
relationship is used to evaluate the infiltration value and runoff
I = (Sy) h
Sy = specific yield
h = well rise
I = volume infiltrated
I = (028) (092 ft) = 0261 ft
62
The difference between the precipitation and the infiltration is
the runoff (assuming no evapotranspiration) Therefore 029 - 026 =
003 and furthermore 003029 - 13 runoff This corresponds in
the literature to a typical runoff coefficient for an inclined
surface of 2-5
Analyzing a longer precipitation period from 18 October 1981 to
1 December 1981 a net precipitation of 043 ft (accounts for
evaporation) occurred less 10 for runoff or 039 ft infiltrated
This results in a 139 ft elevation increase The well water level
actually increased 132 ft shy only a 5 deviation from the
calculated
From tnis investigation it is seen that a large proportion of
the precipitation has the potential to be transmitted into the
landfills saturated zone Exceptions are wnen heavy precipitation
periods exceed the soil percolation capacity frozen ground prevents
infiltration and direct evaporation and evapotranspiration recycles
the ponded surface water and infiltrated soil moisture back to the
atmosphere In retrospect water temperatures within the monitoring
wells could have been measured to indicate thermal effects from the
landfill on ground-water temperature Ground-water temperatures
were assumed to be 50deg F (9)
63
Specific conductance measurements serve as an indication of
contamination levels These measurements are used to trace leachate
movement which represents ground-water flow patterns Factors which
must be considered when monitoring pollutants are the attenuation of
the leachate contaminants which occurs both in the zone of aeration
and the saturated zone The former is a more complete process
Dilution dispersion and cation exchange are the primary factors
involved in decreasing leachate concentration in the saturated
zone The glacial outwash materials of southern Rhode Island do not
have a cation exchange capacity or a high buffering capacity so
attenuation is simply by dilution and dispersion (22)
The NW well consistently exhibits relatively low specific
conductance levels even though it is in landfill material It is
situated in a drainage swale and ground water elevations range from
543 to 5944 This is several feet below the upgradient stream
elevation of 64 feet which is less than 400 feet away The bottom
of the wellpoint is at an elevation of 5312 feet well into the
landfill material Infiltration from the stream to the landfill has
occurred at this location
The W well is situated on a bedrock high adjacent to the
landfill approximately 900 feet from the upgradient stream and its
water level is higher in elevation than the excavated pit (West
Observation Hole) which is 300 feet directly west The W well
maintains a contaminated level A poorly graded drainage swale to
the west of the landfill provides areas for extensive ponding and
infiltration to occur which explains the drop in conductance after
a high runoff period
64
The SC well is located in landfill material and has a
conductance of over 8000 umhos This indicates that leachate is
undiluted The oottom of the wellpoint is at an elevation of 389
feet which is situated in the landfill material
High specific conductance measurements in the west observation
hole and well W and their relative elevations indicate a
west-southwesterly flow direction from the landfill Infiltration
recharge and leakance from the stream into the landfill provides the
necessary elevation to cause outflow in this direction
Contamination from the landfill to the surrounding streams is
evident (Table 4) During the period 15 August 1981 to 27 Octooer
1981 there was no flow in the stream that Borders the northern and
eastern side of the landfill until a point just south of the E well
was reached High specific conductance levels in the EC and NE
wells were recorded (1000 jjmnos) At a point directly east of well
EC a pool of water existed that was relatively uncontaminated which
is designated as the East Stream] location (Fig 10) At a point
just south of that (East Stream^ polluted water in the streambed
was flowing at a low rate This was measured at the SE weir
location and which had a high conductance also Flowrates varied
between 6 and 23 gpm and specific conductances were over 350
pmhos This low water table condition flowrate is the baseflow from
the eastern side of the landfill and indicates a southeasterly flow
direction from it
Streamflow commenced in tne northern part of the stream 21
October 1931 and the north dam oegan to f i l l Stream specific
65
conductances were low indicating a clean water source Tnis
continued until 17 November 1981 when the dam overflowed ana flow
throughout the east stream began A weir was placed at the Rose
Hill Road NW location and was compared to flowrates at the SE
location Flowrates decreased and specific conductances increased
between these two locations
To further investigate the condition of a lower flowrate
downstream than upstream an intermediate weir was placed at the E
weir location (Fig 9) This snowed tnat the stream from the M
weir to the E weir was losing water to the aauifer (influent
condition) and gaining water at the SE weir (effluent condition)
The condition of a net loss of water between the NW and SE weirs
remained until 19 December 1981 when a snowmelt rain condition
caused increased surface runoff and a net increase in flow at the SE
location Upon analyzing the March and April 1982 streamflow
conditions the expected case of a net ground-water pickup from the
E to SE weir continued The explanation for tne initial net loss of
ground-water is the fact that the leakance from the upstream section
was being discharged into aauifer storage to raise the ground-water
table to an eduilibrium level Upon reaching a high recharge
equilibrium steady state condition any additional input will
eventually be transmitted as baseflow out of the landfill and a
downstream net pickup will occur A hign water table condition
prevailed during the January through May period maintaining this
condition In April the north dam broke through reducing the head
in that area by 4-6 feet The 9 April 1982 monitoring revealed that
66
an influent condition remained between the NW and E weirs but at a
reduced rate The 21 April lower stream flow condition shows a
small pickup of water between the NW and E weirs indicating the nigh
water table and low stream flow conaitions combined with the absence
of the dam had changed the conditions to an effluent condition
This was evident in the May monitoring period
Evidence of contamination on both the western and eastern sides
of the landfill supports the existence of a ground-water divide in
the landfill The west stream which drains the excavated area to
the west of Rose Hill Road shows contamination pickup between its
northern section and the SW weir The W well and ooservation hole
indicate high contamination levels which reinforces the concept of a
contaminant outflow to tne west excavation stream
As shown previously flow towara the eastern side of the
landfill is evident from the nign specific conductances and specific
conductances increases in the stream This is especially evident
during low flow conditions when the stream starts at a point to the
east of the landfill and flows with high specific conductance levels
From the literature a relationship between specific conductance
and dissolved solids exists the dissolved solids (mg1) are
approximately equal to the specific conductance times a factor
ranging between 55 and 09 (39) in this case it is taken as
065 (41) The dissolved solids increase coupled with the stream
flow increases provides a basis of calculating the dissolved solids
outflow to tne stream This calculation method was used in a
previous study (26)
67
The relationship
=Cinout Coutflow Qoutflow - Cupstream Qupstream Qinput
where the numerator is the streamflow pickup and the C- and
Q-jnput is the concentration and flow input from the ground-water
This can be used to estimate dilution level outflows from the
landfill Initially this is used for the ambient ground-water
pickup between the E weir and the SE weir This entire flow doesnt
come from tne lanafill but much of it is conaucted in the high
transmissivity area between the lanafill and stream from upstream
leaxage ana surficial recharge Tnis is evident when this section
of the flow pattern is analyzed on Fig 22 Therefore the landfill
outflow is mixed with tne ambient groundwater flow which dilutes the
landfill leachate before it enters the stream To illustrate-this
concept a calculation using the 9 December 1981 monitoring is used
At this time a flow of 672 gpm occurred at the SE weir with a
specific conductance increase of 7 ymhos between the E and SE
weirs The dissolved solids increase would be approximately 795
Today in tne stream
Where
Co = 90 jumho at SE weir
Qo = 672 gpm at SE weir
Cus = 83 jumho at E weir
Qus = 606 gpm at E weir
Qinput = 66 gpm gain
Cinput = 154 jumho
68
The 154 jumho value represents the contaminant level in the
ground-water adjacent to the landfill
This relationship is applied to approximate the concentration
level dilution in the ambient ground-water between the landfill and
stream The aforementioned relationsnip is in turn applied to the
landfill outflow into the ambient ground-water flow adjacent to the
landfill The ground-water receives landfill leachate dilutes it
and then transmits it to the stream The previously calculated
value of 129 gpm was used as the outflow from the landfill
Co 154 jumho flows into stream
Qo = 67 gpm flow into stream
Cus = 83 jumho background level
Qus = 67 gpm - 129 gpm = 541 gpm
Qinput = 129 gpm from landfill
Cinput = 451 jumhos
Approximately tne same contaminant levels from the landfill (tbl
umho) are arrived at as existed in the summer streamflow conditions
when the upgradient ground-water flow adjacent to the landfill was
at a minimum
In addition to using specific conductance to define
contamination zones electrical resistivity can be used to indicate
contaminated areas The measured earth resistivity is inversely
proportional to the conductivity of ground-water Water containing
contaminants with high ionic concentrations are more electrically
conductive and will have lower resistivity values than surrounding
natural ground water Therefore resistivity methods can be used to
69
delineate plumes of contaminated ground-water that have hign
specific conductances This has been demonstrated by several
investigations (11122328374045)
In this study a Schlumberger vertical electrical sounding R-l
was made in an area of known contamination at the W well (Fig 12)
Given the geologic constraints provided by the well boring log a 4
layer computer model was used to match field survey values A
Schlumberger sounding R-2 in an uncontaminated area north of the
landfill in the same geologic setting was used to provide a
comparison background sounding (Fig 12) A seismic survey N-4 was
made to obtain water table depth and depth to bedrock as input
parameters to a four layer resistivity model (Fig 8) Tne results
of the electrical soundings have been tabulated in Table 6 and
plotted in Fig 27 and 28 respectively
The ascending portion of the field Schlumberger curves were
initially matched using a two-layer ascending type master curve to
provide an approximate depth and apparent resistivity of the
overburdened topsoil layer (8) Tne second unsaturated layers
apparent resistivity was determined by using the graphical
interpretation of total transverse resistance The total transverse
resistance is approximately eoual to the peak value of the curve
times the corresponding Ab2 distance it occurred at This in turn
is eaual to the sum of the first two layers apparent resistivity
times their corresponding layer depths
70
bullH
OJ bull bullH 4J CO CM
c ce G bullrH
j-gt ca c c a 3 ltu O L
co CO 0
bullo Q bull laquos c n 3 -U OrH f~ 3 bO ltn y CO O cc CO ^mdashN
QQ bull
bO bOJJ C C Ci_i
O l T i O O O O O O O O O O O O O O O O bullH bullH mdash^ bullo 0 C c3 f| 3 O raquo O CO CQ
CO
rH
CO O
L 4J
^ltU
i- 1 ^n ^b O 4-) bull2 CM bullH C OJ 1 -U bullH CO C L O a ^-^ 0) a
rH c a L CD ltu (1) 3 tlt bO cO I
3 a 0) a Q 4J laquoa e CO 3 (H bO c C O bullH
CO TJ C 3 bull
bull O bO -i-3
0 CO C O3- O G O O O O O O O O O O O O O O O O O O ft rt1 -raquo - t l S^ ft tfigt f I mdash^ K_ l_ raquo mdash I gt fgt I l 1
(1) 0 rH CO CJ JD o^^ CO CO CQH lts
71
Legend
A actual field measurement
-e- interpretat ion
10000 bull
6000 bull 5000
4000-
3000shy
pound2000| ltD
_ r 1000
09
5 600 pound 500 - 400
I 300 a a lt 200
100 10
Fig 27
20 30 4050 100
Distance AB2
Schlumberger Sounding
200
feet
R-1
400 600
72
loooot
6000 5000 4000
3000+
laquo2000 e
r 1000
raquo 600 pound 600 ~ 400
$ 300 a a lt 200
100
Legend
A actual field measurement
-Qmdashinterpretation
10 20 30 40 50 100 200 400 600 Distance AB2 feet
Fig 28 Schlumberger Sounding R-2
73
Formula T = f
Background Sounding (9000)(15) = (3110j (1 7) + gt2(8)
= 16214 n- ft
W Wel l Sounding (b200)(60) = (500) (2) + pound2(28)
= 13250 SL- ft
To determine a resistivityp3 value for the third layer a
graphical interpretation for the longitudinal conductance S was
used(48) This is eaual to the sum of each individual layers depth
divided by their apparent resistivity
Formula S = -r1 +~r-raquobull-ra
Background Sounding 0017 = yyg + ~^
= IbOU - ft
W Well Sounding 0285 raquo -ggg 7^3 J~
= 179 v-ft
These values were input to a program which calculates a
schlumberger sounding curve (47) The theoretical sounding curves
approximately match the field curve as viewed on fig 27 and fig
28 To provide a check on the apparent resistivity of the saturated
layer at the W well the following relationship was applied 1OOOO
= spec-jfic conductance (umhos)
74
At the W well the specific conductance was measured to be 3 00
jmhos at approximately 10degC
Assuming a formation factor of 45 for the glacial outwash (23)
material Archies law is applied to estimate an apparent resistivity
of the third layer (7)
fgt FF x p
A= 45 x 103-n-ft
A= 4G3 JL-ft
This is a reasonable approximation to tne 3i= 179^-ft calculated
analytically from the sounding curve interpretation
75
Remedial Measures
With the analysis of f low patterns and contamination zones
recommendations to minimize the environmental impact of the leachate
can be reviewed The basic technique is to minimize all sources of
water reaching the refuse so that leacnate production is minimized
The oiversion of precipitation by a relatively impermeable cover and
proper channeling of runoff would minimize percolation into landfill
material Caps and seals can be constructed of clays fly ash
soils soil-cement lime stabilized soil memorane liners
bituminous concrete and asphalttar materials (15) Proper
contouring and grading will help minimize infiltration If a soil
cover is used a vegetative cover can be planted which will utilize
some of the infiltrating flow through evapotranspiration losses
during the growing season By minimizing the length of slopes and
providing proper drainage channels tne surface runoff can be
conveyed to a downgradient area outside the recharge zone
Therefore this surface water will not increase leachate production
from the landfill Also by increasing the slope of the cover over
the landfill itself a higher percentage of runoff and lower
infiltration will occur
To minimize upgradient ground-water influx to the landfill an
impermeable subsurface barrier or intercepting trench could be
used Barriers can be made of bentonite slurry-trench cutoff walls
grout curtains or sheet piling cutoff wal ls extending to the bedrocic
or an impervious layer to effectively prevent water passage or
create a head loss that wil l lower the water table In addition an
76
intercepting trench which has a perforated drain at tne lowest part
of the water seepage zone could be used to intercept and divert the
entire flow
These possibilities have been evaluated with the help of the
model to determine workable solutions for this landfill The
primary concern is to eliminate leachate flows to domestic wells
Initially a simulation was run that eliminated recharge over tne
landfill area (Fig 29) This had a considerable effect on the
ground-water flow patterns of the landfill area The mounding that
had previously occurred under normal recharge conditions was
eliminated and a general drop in the water taole within the landfill
of 2-3 ft occurred The effect of eliminating recnarge over the
landfill when the upper stream is running would cause greater
infiltration from the stream as evidenced by only a 2 ft head loss
in the landfills flow conditions This is evident when comparing
Fig 29 with Fig 24 Tnis indicates that this measure would only
marginally reduce the resultant leachate flow from the landfill
material that lies below the water table In another situation
where there is not such a strong potential for upgradient flow this
measure has proven quite effective (6) In this case the landfill
cover consisted of four layers an intermediate sand and gravel
cover immediately above tne regraded waste materials a 4 inch sana
bed designed to protect the overlying membrane a ilO mil flexible
PVC membrane and an 18 inch final cover of sand and gravel
77
Legend
landfill limit -raquo- -^ -raquobull excava t ion x-^x- s t ream
400 copy WNWNEECSESC monitoring well locations
= -= unimproved road fee t
Fig 29 No Recharge over Landfill
78
Controls such as 10-30 mil polyvinyl chloride covers favor the
development of an anaerobic environment which increases waste
decomposition time and would necessitate installation of gas vents
at several locations on the landfill cover Tne integrity of tne
synthetic cap may be further threatened by subsidence which create
differential stresses on liners Settlement would create areas for
ponding and depression storage and eventually necessitate regrading
the landfill surface The landfills south-central area has oeen
filled within the last year and will prooably need to be regraded
due to settlement within the next few years
Another possibility for a liner would be a soil-bentonite
cover A layered cover consisting of natural materials with low
permeabilities such as bentonite clay followed by a layer of highly
permeable material such as sand and finally a layer of topsoil can
be used Due to potential drying out and cracking of the clay liner
a synthetic liner is the preferred method
The most immediate technique is to grade contour and vegetate
the landfill cover which has been done at this site Althougn an
impermeable cover would probaoly reduce the amount of leachate
produced it would not eliminate the upgradient flow and provide
guaranteed protection of wells in the vicinity of the landfills
northwestern section
A slurry trench along the northwestern perimeter of the landfill
would effectively cutoff upgradient infiltration and divert recharge
infiltration in a southeasterly direction thus removing possible
leachate outflows from the radius of influence of the neighooring
79
wells This has been simulated using the computer moael ana flow
patterns as shown in Fig 30 Contour lines are distorted in the
vicinity of the slurry trench due to the 200 ft nodal spacing
Transmissivity values of 1 ftday were input at the slurry
locations to simulate an impermeable barrier Tne surface recharge
at those nodes does not infiltrate the relatively impermeable grid
nodes at the slurry locations and flows to the edge of the noae
thus creating a dramatic head loss within a short spacing To
effectively simulate this a variable grid spacing should be used
with reduced node grid spacing at trench locations to eliminate
distortion The computer simulation shows that the slurry trench
could direct flow in the landfill area in a southeasterly direction
and away from endangered wells In addition it would reduce
upgradient infiltration from the stream into the landfill This
measure would prevent leachate from spreading beyond this carrier to
possibly contaminate neighboring wells
The combination of both the slurry wall and impermeable cover
would be ideal measures to minimize generation of leachate and to
stop its spread to neighboring wells The slurry wall without
recharge over it or the landfill is simulated in Fig 31 This
indicates a lower water table tnan eliminating the recharge to the
landfill The slurry wall has blocked upgradient ground-water flow
at its location to the landfill
80
Legend
landfill limit -laquo- j -laquobull excava t ion ^^- stream
copy WNWNEECSESC monitoring well locations
= = = unimproved road ssi slurry wall
f e e t
Fig 30 Slurry Wall
81
Legend
landfill limit j- j- J- excavat ion x-v^gt- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road s==s slurry wall
400
feet
Fig 31 Slurry Wall without Recharge Over It or Landfill
82
An intercepting drainage trench is considered next If a trench
was excavated to a 30 ft depth in the outwash material extensive
shoring would be required In addition difficulties would arise
when the trench was excavated below the waterline Tne trench would
be sloped to provide drainage and backfilled with a highly pervious
material to intercept and divert leacnate locally a conouit which
is perforated on the top to allow infiltration and unperforated on
its lower perimeter to permit continuous drainage to the collection
treatment center would be installed on the bottom of the graded
trench The difficulties involved in excavating below the water
table ano shoring the sidewalls to permit implacement of a drainage
conduit at a 30 foot depth make this option increasingly infeasible
83
Conclusions and Recommendations
The location of the South Kingstown landfill in permeable sand
and gravel glacial outwash material (107 ftday) combined with the
high hydraulic gradient across the landfill area (20 ft1600 ft)
creates a high potential for ground-water contamination to occur
This is intensified because refuse nas been placed below the water
table The low hydraulic conductivity of the compacted refuse (1
ftday) and the excavated area to the west of Rose Hill Road have
both contributed to modifying the original southeasterly flow
pattern These modifications have created a ground-water divide in
the landfill at approximately the western third section Tnis
results in approximately 13 of the leachate flow from the landfill
or 63 gpm flowing in a southwesterly direction and 23 or 129
gpm flows in a southeasterly direction Infiltration from
precipitation recnarge over the landfill (up to 9Upound) and from tne
upgradient stream during low water-table periods provides tne
necessary influx into the landfill Evidence of contamination is
clearly seen on both the east and west sides of the landfill which
reinforces the previously stated flow patterns
Of the several remedial measures reviewed the contouring and
grading of the landfill topcover and drainage swale provides the
most immediate protection The topcover has been graded mulched
and seeded to provide a low runoff slope generally to the east
The drainage swale on the left side of the landfill has improperly
graded sections which should be corrected Its northern section
could be drained into the northern sections swale and the southern
84
section drained to the southeastern section of the landfill Tne
point of the drainage swale which divides the northern drainage
swale from the southern one should be determined by a field survey
Cost is a major contributing factor when determining which
remedial measure is to be applied to the given situation For the
purpose of this report cost estimates are not presented but rather
the effectiveness and feasibility of the remedial measures are tne
primary considerations As was reviewed and simulated in the
computer models the slurry trench and impermeable cover over the
landfill are two viable options that would effectively provide
protection to the domestic supply wells in tne vicinity The
impermeable cover would eliminate precipitation recharge into tne
landfill yet drop the water table only a few feet due to upgradient
infiltration from the stream This would decrease the hydraulic
gradient thus diminishing the potential for a contaminant outflow to
surrounding wells The supply well of primary concern is one to the
west of Rose Hi l l Road marked well D on Fig 2 If contamination
occurs in this well the most effective measure would be to block
off leachate flow in this direction by installing a bentonite slurry
trench at the location indicated previously This would effectively
prevent leachate flow in the westerly direction and diverts it to a
more southeasterly direction In addition the slurry trench
precludes infiltration flow into the landfill from the upgradient
stream
85
Tnis report has effectively reviewed tne original ana existing
flow conditions and contaminant levels in the vicinity of the Rose
Hill landfill The purpose was to provide an understanding of
ground-water contamination patterns and study possiole remedial
measures
86lt
Appendix A
Precipitation Records
Monthly normal precipitation 1941 -197O
i$l Total monthly precipitation
KINGSTON RI
14
ia
^JO T I bullbullL
pound 111 laquobull
4
a
n
-
^
-
-
KS1JAN
^Ii R3 HB MAR
1
1 APR MAY
1
1 JUN
1981
JUL
-bullraquolaquo H
AUO SEP
K3~~f$s bull
_imdash
i1S 1
OCf NOV OtC
171 1 iI1
JAN HB MAR APR MAY
198
Fig 32 Precipitation Record
- - - -
IM 1 MtvJrflgtlgt c ortli-A t lUN I r nraquo rl - -
gt|MO CLIMATOLOQICAL OUSERV ATIONshyr-r bull JK gt raquo - 1
i5fWA I VAPOR Al IOH -bull AIM If MPCRATUM bullF 0 riccipn AT ION UNO IlMf
bull 14 H 14 H mdash Vshy ADDITIONAL DATA IfUAlUS OATt 1 bull raquof bull bull 1 ta
14 Hw rlaquo4 w bullbull bull 1 114 1mdash4 (llrl 1 1 1fl Hll
0 kmdash
Mraquo M4 raquo i T i 4 bullraquo-laquobull i i
Lgt f 1 21 S 1 Hbull - - bullbull -
ltJL 1 2 01 - - _ _ 1
mdash
-
1 12 _ Q I
mdash shy
mdash 4 (C ( - - fVi 1 - 0
1 (1
^ 1
Vvraquolaquo IJ1^ raquo CP O 3L 1 Z - i bull j-t-J
1 J
LH Vb T n 0
1 gt fl oo O ~l 2 L - bull 1 P )laquo jn iP IP - OOI L5L mdash shy
-t 84 ^(^^ ^fi P i flja 0 JO II 10 tl tcgt 7 J IV wllaquo
h l2L bull 0 lt -_ shy
-id VJ lt 3C 2 ft OOL -mdash
U 71 C1 Sr 2 13 2 nl JLJraquopound HP r M ltf1- (
IMe 2 ii O It
n jlt dl 1 1 bull o o-il ST i 1 i 25 2-x-1
-
ri
i tlL O mdash gtbull bullgtlt 1ft -o- is Oil So iJK 2-io otv u 31 fil loi 2 il Oll it Of wr is i1raquo -iZ 1 deg|0 01
M IT So - mdash
- 13 1 CT mdash i - mdash 21
shy
Tl Ci av ZUll IMT 0 IM Pe v _ 1) T) S) ii3( dlt Ii 2 lt^2 II li- S1 riivi To 7HX lt3lO 14 ^2- iTi I li 011 -- - -i -^IS no 5^ or i | T Jift laquoV OoH bullla It Va iCO mdash L OIL 11 bullvf poundgtpound lS_ flv oh P-lfe 1 poif _ shy11 IB kl (4 itlaquoT lamp llt0 oot^
mdash -n
It T1 |ir( L1 HI 2 0 oil
U 1M ft go C ICf^ -^2 Z laquo-|o
11 it 5 bulln - TO o abull Li u-i IT1 -- Iw O ltM (I bullbull bdquo-I(K 1mdash -tilltLlA ttfe
i Dgt ac -- U 44 4 11 1 1- ytd i i_i J-K 0 i if -i i i V t Wl raquoOHM 1-1 US D C P A R T M f N T OF COMMfRCE t 4 1 IUII 1 1 ^~) mdash
llaquo- Hi NC bull bullh bull bullJL^V HBl CO 00
11
)jLsVyr^gturv
^ | TKu
|-_t_ bull(
IIMgt I I Mt|UU III- II 11
PNECIPITATIOH
I 1 1 IMX
IMO
bull llfclaquo I UCIUKI) Ur C V A r U M A AHO CLIMATOUOCICAL OBitH
E V A F O R A T I C r i Jttffl laquo amp hMIlaquoJllaquoJIIlaquoBgt
DATE AOOITIOMAL DAIAKMAKk M
bullraquobullmdashlaquo
tp 01 (1 Of Ll OOI ooo
0^1 o-i 10 tl |00 102
OC (1 13 Ofl
it i rc DS os an
(1 SV o
Ul 010
(ISl 101 I on
130
II 5= Otl
ss lt 001 (IK Ml
jt il HIT
7 it
ow Wo 17 Top 2-01 OIO
(0 oov zi oot
u CO ^A 0 to Zoi CLflS
bull50 01 ljtj
nshy 5H LO OIt
50121 IVO QJO
14 Co Ho LO Hl ^pound Jl 1
ltM ool fllc
H Tl 01 II
11 11 Q1
iH OIO
HO 2 llaquol 11 II
lifc
IV-IIM ul OIPAITHINT or COHMIICC NOAA
NAtlOHAL gtIATnlaquoll raquotraquoVlClaquo CD
r~
All TCUMMATUNI ^V UII rgt ITmi 1 Cwphu Obic i gtn t ngir-H 30
rilCiriTATIOH
JJ T I rTJ-rimdashr-iramj|MP CLmATOLOQ
laquolaquo jftilCiii bullIHO
Oi1l ADOITIOHAL DAIAlllu
Ilf4ft
Sii1
(1 2 IO OO
Hl ii SO
us OIM
Q^L
a A3 Hi SZ Sf^ bull 12J2
HI Z-SF OOl 1C t HM IA H ICP fiJA
OOl 10 (310 sn 310
if HI (0 ^01
bullit SO 28H poundJ1 11 006
14 35 TX oon II (bull2 it zr II c-S
rr Zll lo 31 OP an 31 a 31 oor
CSW O-ll Si CC Of 011
Oll _ I |ft
00
u i oerraquolaquoTMiMr of c NOAA
NATIONAL K C A T N C M SCMVlCC
TC^S lk)oiVroTJA
TETT I 7X
1raquolaquolaquo 4 bdquo ir lt er ni I^OV ltqgl j--^ TQ
MICiriTAllOH ITIND
D|mdash
b5NO ctiUATOtoiCAL oeit^
OATI AOOITIOMAL OATAVlHAtt
0-tt
Mlaquoh bullbullbull- rshy laquo
I- ltltriu HI I 4 bulllaquobullbull1
Zii
30 Dfellt otvt
at HA
OOI
62
iJ_S2 HI if
bull- 20 SI 2i So
So
VVfr
OSfc
I (
Jtlt
3aoi
r j -bull ie MA
Irill iiol
in^ 14
Mo
Zll
214
21 1P
00-i
bulliron
17
bullr
11 i ir- I J Ktf^c
US D E P A R T M E N T OF COuMEDCC I | C gt A A
K AIlaquo Ttupf lATuit r
|SlVi AlJ PIICIPITATION
oJud (El
VIM i Uraquo
MIND E
EVAPORATIOH flnrft bull A ftufiifccdll
KECORO OF eVAPllHAtlil bull I CLIHATOLOOCAL OBSERVA ^Hij
14 MM A_M AOOIIIONAL DATA11 MAIM
Mr bullH Oo|
M Si lift
bull221 IHI
ZS Ji 40 IZV
icr KS I
HZ 111
bullT 21
loA UK JA IP
v^ ft
1M 2Sshy IT Tl
71 V |
i I 31 1deg a
uty^ U bull3
ons 1 CiO TxX
HHO (10
3H 19 12 10 IP
raquo3H raquo | 5t io
OP OIT
14
vO UI Of PANTMINI Or COMMCRCf MM O A A
F ngt TIHH
iiicffwiffc 4 rJ (TIM bull Cempltit Obitittiio
AIlaquo TIMHIATUM PHICinTATION I V A f OK ATlPrl
OATI ADDITIONAL DATA KMAlIt
U4laquo4 +
03H Ji
10
rc a 1 16 oi ii
tiiy 10
OI
II i23 or o 13 -y~ou HO
II 3V III i 3 t
V laquop oot
OM1 SS ne
T an -i IP
Olt zr LTV
3T 001
a -11 2T
10 an 31
-1 raquo 131 UP 3H lf 14 Lpoundshy
it 14 30
IS
Ui O I P A K T M f H T OP COWlf ICfM O A A
NATJONAI V C A T M C n f t K M V l C K
bullbullbullbullbullshy -2 o AIlaquo TIMMRATUM f fKICIPITATIOH
OATI poundt- MMINMAL DATAk
ZP 51 lo icr
011 111
OoT IHf
Ut 003 am
3o 13 ao
4A X 05shy
H4 i IjJyiV131 ooc js
IH oi 01 tL 18 13 a
No 11-7
rivgtp OO| M Hi 03 01
It 12
bull I 41 bull7119 14 ^^ raquo 31 15 lampk n M ho i
Jo -j-
-J
I
Ml H^ I _
amp2ampUi^= LS 0 S 0-f bullTTT
-Vmdash gt U_ bull 1 rOHM I- 11 OI OCPARTMlNT OF COMM(NCC
HO NATIONAL W f A T M f H ftfraquoVlCI
98
Appendix B
Boring Logs
99
X iHECT 1 ff 2
OAT American Drilling amp Bor ini I Co Inc
wo WATH smn EAST PR ov IDENC E ft 1 Town of South Kingstown South K ngstown R I MOLENO X-J
TC 100 RCSS bull ujrMonitorinq Well Installation | South Kinqjtown R I UNC a STA Pf KXICCTHJ LOC ATK3N
bull cfrserrr TO above S MPLES S FNTTO _ _ |laquolaquor A-109 SURF ELEV RE PORTSEr
GROUND WATER O6SE RVATC MS 1 CDREraquolaquo m-T nn75 laquo A 256 - 20 mdash Hew y
Instolled 32ofT-l2 PV C - JO- COMPUTE 111275 K toia 3- I-WI 1-38 TOTAL MRS bdquo10 screen BORING FCACUAM J K lanq MAI rraquo HomnwWI 300 140 IampPCCrc Mamlaquor Fall 24 30 lampaaiona SOLS ENGR
LOCATION OF BORING H ONITOKING WELL
Coung Samplt Tjp Blow per 6 Manure SOU IDENTIFICATION Strata SAMPLE ^^^yV Bloot
foot
Otptni
From- To
el
l
on Sampler
0-6 1 -6-13 12-18
Dentity or
Conmt j
Chang Remark include colo^ graaation Type of tod lie Rao-coMr type condition nordshynetiDntotf time leamt and tie No Pen Rtlt
2 No top sample 5 12
1 loamy fine sand
bull)^ 40 30 36
5- 616 0 23 20 16
noist iense
Brown fine to coarse SAND some fine to coarse gravel Trace silt
^
1 18 18
36 8-0shy57 40 30 V 35
|0-||-6 D 14 24 20 Srown medium to coarse SAND Some fine gravel cobbles
7 IRshy 16
27 75 37 3
IS- I- D 5 14 16 3bull
ISshy 15
42 50 I9--0shy50 65 20-2ll-6 D 9 23 26 bull Jrown fine to coarse SAND Tbullwshy 1Z 75 90
22-0 Trace silt trace fine gravel
124 120 74 60 52 41
7S-ltlaquoil-A DX 71 16 13 wet very dense
Gray-brown fine to coarse SANC Some fine to coarse gravel little silt
H IR u
40 30--0
3C-30-IO
3l4-334
334-3314
38 4-434
D
c
C
C
7 IflO
94 6
we tr j
y se
ft irox
30MOshy
31 -4shy
Gray-brown fine to coarse SAND Trace silt
Gray-brown fine SAND some lilt trace fine gravel
Too of Rock 31 -4shy
Gray-pink GRANITE
6 7
amp
CJ
IltJ A
60
601
IQ mdash
2(
4
5 i Hard
ft 5ome seams bull
GROUND SURFACE TO J 4 U3CD_ ^JVrf bullbull( tutu t to 4o 4 SampM Type Proportion UMd MOB Wtx 3 OfaM on 2OD Sampler SUMMARY-
OOry CCartd WltWen4 Hoc OlolO Canmonieraquoi Don any CoKeem CarMWncy Earm Barrlaquoj 11 14
UPgtUnOigtturod Piuon trite (Oto20dego 0-Kgt Loei it 0-4 Sait 3O+Hofd Rock Corng 14 Kgt-30 laquo4 0 rte 4-8 MSHM Samplet TPTtitPit Ai Auger Vvanefett tarn 2Olo39 3O-M Owlt n laquo-lS Strlf rinit nn v 1
UTiUndlshffbed ThrMOll and bull 33to9O 5O Very 0laquo nraquoe 19-30 V-3trraquof - | OLE NO X-l
TOVH rim - iA it raquotoraquo
100
SHEET 2 o_L
WO WATEt STUET [AST ft OVIDENC pound a i American Drilling amp Bor ing Co Inc
MCLl WQ X- 1 Tt AOORCSS i
LIME A STA KXICCTMJ tuf same as 1 | tame as i LOCATION
W PORTSEf mo OB nj urt eflaquo T
illtPLES S
P
CVTTO nlaquo mun orv
^s f^ Tin i GRCVMO WATER OBSERVATONS CASING SAMPLER CORE BAR
START Typi COMPUTE tome at 1 same aiH
TOTAL MRS BORIMG FOR CMAN n bull IT INSPECTOR SOILS EMM
LOCATION OF BORING u HfVJTneTfi UFI _
8
Counf Blo-t
foot
Dtpllo
From To
0( on SampMr
0-6 f 6-IZ
Moittir
Oonuty or
Contilt
Strata Ctnngc
SOIL OCNTiriCATION Rtmorkt ineHifl cotot grqdotion Typlaquo of Mil etc Roo-axtrPlaquo condition Mrdshynlaquot Drog tun ttomt end tic
SAMPLE
No Ptfl RfK
434-4o4 c
approx 7 minj
per toot 454
Gray pink GRANITE Hard Fairly solid core
lt_4 24
Bottom of Boring 45 -4
-
~
bull 1
GROUND Sorrow Tye
SURHCZ 10
bull OiOry CgtCord WWothod UPUnditiurMd Piston TPlaquoTtraquotPtt AtAuotr VVor
UTltUndinrvd TTMMO bull bulltat
iivnPilaquo(onioni Uraquot4
me OioiOItttt laquoraquo20
wmt Z0ie33
and 361090
c M
C1 5 Si
-SOshy
ASING
IOtgtWtigt bullnlot Dn 10 Loci M Mod 04 SO Dm 1shy Viry 0laquo
s _
TMEN 0 hMl on 200 SoiTBUr laquoity ConcMMt Conorawncy gtbull 0-4 Sort 30shym 4-B MStlfl M BH9 Strtf bull ts-so v-swt bull
t-HOrt Ear Bern RoetCorrt
i ^^^^^ bull
-[MOLE no x-i
101
raquoMEC rAmerican Drilling amp Bor in g Co Inc 1 ofj_ DATE wo WATlaquo smn UST Plaquo IOIDCNC j laquo i
Town of South Kingstown South Kingstown 8 MOLE MO Jlt Z TC rx MCS3
rtprr uAurMonitorina Well Initollation | South KinqitowrxRI UNC A STA P KATIOM ME POCT ^rwT TO above I OFFSZT
uD^r laquorlaquorTTO 6 -109 suw tLEv Sgt louffJOCNO
0 tj Tlmlaquo WOUND WATER 06SCRVATC US gtW Rsdl SING SAM^EH CORE BAH
26 ^_ 12 $TAlaquoT UL 2Z2i Ji r TTP NW ltA sr IJZC Z5 CCOMPLETE
SitLO 3 I-3B- 1-38 TOTAL MAS 41 BOAINO FOACMAN JK1 ana nf ni n MonwwWl 300^ 140 BIT bullK^CT
gttonvrar Foil J^laquo 30mdash Diamond SOOJIEMGM
IE HFII
iCaunq SampM Trplaquo BMMtpw6 UOIIIK- SOIL DCMTIFKATION Siraia SAUPLE Blow DlaquoPIAraquo of on SompMr HtmorU mcJuo cotes gradation Type of Dwuily
pw or CXang writK Roel-eolorlyp condition tvort-From- To Vfoot 0-6 f 6-2 12-18 Coniitt egt rwtiOnAngtimt wamaondtte No Praquon Rtlt
2 Brown fine SAND little silt 2 2-0shy5 15 18 moist Browi fin to coarse SAND 18 5- 6-6 0 14 25 27 vlaquo Troc fin aravel | 25 wy Ifl 11
dlt tns 35 40 38 moist n in-il-i Lgt U 15 18 ie is li1 Irl IS 31 I2-0
~~43 1
A) Jrown coars to medium SAI MD 48 moist Little fine to coarse gravel
|5-IA-Xlaquo 14 47 41 fn D laquo y Little silt rrqa coarse sane 3 18 I1
68 In IS 44 32 34
n ^n-^i-A- w 2o 19 29 wet 4 la -59 lens ltfO no
25-0 2amp bulllaquo- 77 c BOULDER r[ 4 i
27-0 5X ~W 24 24 bullWar- 5 Ifl irown tine to coarse SAND some
dens 29-0- Fine-coars gravel trace silt
30-3I oxx 30 32 30 moist irown -gray fine SANDiom e 6 l rr Vlaquoy 31 -0 silt trace fine oroveTILL
Bottom of Boring 31 -ampbull shyBent casing -pulled out and moved over 4 - washed amp tJrovlaquo casing to 30 -Installed 3C gtof 1-12- PVC - 10 screen
WOUND SUraquoraquofCE TO 3pound 1 yijfD MW t ASIMC TMCJ laquo olaquorod -bor of borina
SomoU T]Fplaquo ProigtuliOraquoH UMd MIOtgtWLx3Orolt lon2OASanlaquoMr SUUMARY-D=Dry CCorad Wlaquoworaquonraquod bullact OiaiO CanM gnMM Daonty CIMIH Caamraquoci EffW 8or^ 2pt
UPiUnairurMd Pition Itnt laquoM2O O- O UKraquolaquo 0-4 Soft 3O-hHard Roelaquo Corrig o- JO M0mlaquo 4-8 MSNff SOTipM 1 p^ 3O-9O OwgtM bull-IS Slid
TPlaquoTraquojraquoPit AAugtr ViVon mini tamt 20to39 UTtundiifir6d TrwMOtf and JSloSO 50-raquobull Vary 0nlaquo [HOLE NO x-2 B-3O V-3Mf lev rim - IAIT raquosectlaquoraquo
102
300 iu 24
1 UMnii ffi 140 laquo 30
CA1INC tf
gt taWCTf
bull 0gtlaquo i R Cook Jr_ R Millineton1 Wttn
I~
1 VAMtl CtMG
1 W HO-t MO
1 Oraquo 1 laquo0~ twt
L 1 laquo-raquo VfcM^lf [wlaquoraquoCI ^ ^ K3Ot III laquo
0-LS D
5-65 D
LlQ 10-115 D
15-16 Tgt
Lraquo 70-51 n
25-26 D
F
I O-O Ci
A Allstate Drill ins Co vi o i
PROVIDING R 1bull raquoraquo uvraquonn~ N M O M I T O P I N G HE1 _^lt -^ PI-Traquo UJU
CUM Town of South Kineraquotown raquoraquo 1 1TA maoer Propolaquolaquod Sit for Slude Disposal nltn
laquo V-449 iampAAtut i a 138 ort STI bull r 42777 CtOuMO IKVtllON
Cill bdquo 258 DA II MN ru 42777 rilaquolaquodO laquoraquoTti rum 1911
AU1TATI
MMUI1 raquolaquogtlaquolaquo laquoKiO itXHHKraquoriOi of sous MUAHI nMTKlion Ot CMlaquoMC|kOraquort tl CO~VH DXltgt raquomlaquo laquotf IMi COIOI C4l II I 1raquo gtlaquo^ Oraquo 1Ol rC t Xgttgt VtfKOe Craquo Mi 1 ft liMraquoK laquo0^tlaquot nfgt
1-2-1 10 TOP SOIL FINE LIGHT BROWN SAND traclaquo of ilt
16-31-17
22-24-21 100 FINE TO MEDIUM LIGHT GRAY SAND trace of fine gravlaquol and raquopoundLt
lfl-37-34 150 LIGHT BROWN FINE TO MEDIUM SAND little poundinlaquo gravel
21-17-15 200 MEDIUM TO COARSE SAND bullomc fine gravel
12-4-10
265
Observation well installed
NOTE No casing blows taktn
bullbull B-23 ow
^w^ 265 I raquo bull raquolaquo bull I W
11 laquot gtbullraquo Vlaquo 14 W gt_ c-shyji bull alaquo bull jraquo VI laquoHshyw bullbull m raquobullbull D-6 raquo Mshy
bull bull laquo Vshy
1
bull bull
I
103
MAMMII Allstate Drilling Co ulaquorr 1 or 1 FftOVIOCKZ H L traquolS mTArm^S MONITOR NR WEL
VNO wr3JJO__raquoraquou_24__ HCU MO P-74 n iu riBwi Town of Slt7H^ Xirpin
mdash^ laquo0J P 1 1 bull ^n^ciit^o TVlaquow^laquott1 bullraquoit wt 140 nu 30 olaquor fBu lkv Waste Disposal Arcai
MUTAH a V-449 R Cook Jr UMlaquoiigti D 1 38 0t| raquoIJ raquo 5277 rlaquo SUMO luvlaquorv-laquow
mdash 5277 fipe -raquoT pfpm 150
H MCIO IMNTlXAflON Of SOU t(kAIlaquoS rrn 0-laquoraquo
5 -SF 01 w in laquobull -raquo ^ lit
D 1-2-2 TOP SOIL V-1-oraquo
15 IPbull FINE TO MEDIUM LIGHT GRAY SAND AND GRAVEL
5-65 D 37-27-35 some silt
10-11 D 20-14-18
15-165 D i 17-14-14 155
BROWN COARSE TO MEDIUM SAND little fine to coarse gravel trace of silt
20-211 D 4-4-2
230 GRAY BROWN VERY FINE SAND
25-26J D 7-8-9 AND SILT 265 fvarvedl
Observation well installed
NOTE No casing blows taken
wta 10 n uuraquo c^imdashbull IgtM laquolaquobull- B-24 ow ~ 14 ltfc laquoraquobull vlaquo^ M laquobull r O 0 fmtt bull W-L 26 5
-0- CgtCmdashgt bull laquolaquobull mdash laquo 1 - raquoraquo 1 gt 1laquo bull 1 gtraquor to bull mdashbull bull bull bulllaquo I t l~laquo 1lt Uraquo mdashbull ) bull 1 gtbull ft 0~ H laquoy bullM ta bull -IN la laquobull OPUM bull($ IMI
mdash H raquo laquo-bull
104
Appendix C
Calibration of Specific Conductance Meters
105
Specific conductance measurements were made using a beckman RB
338 temperature compensating meter and a YSI rtooel 33 salinity
conductivity temperature meter The YSI meter is not
temperature correcting A formula to compensate for temperature
differences to standardize YSI measurements was used (21)
A long probe for the Beckman meter was used to measure conductivity
in the wells Differences in conductivity between the YSI ana
Beckman meters and the Beckman short and long probes exist These
were calibrated in the laboratory using 001 N and 01 N KC1
solutions Values presented are Beckman short probe values The
Beckman long probe values were reduced by 76 and tne YSI values
were multiplied by 11 to adjust to Beckman short probe values The
YSI meter was used in the latter phases of the study for the
stream contamination due to the greater accuracy of the dial readout
scale
Table 7 Specific Conductance Meter Calibration Table
Concentration (KCL) 0001N 001N
Specific Beckman short 145 143 143 1247 1245 12GO
Conductances Beckman long 190 191 188 1639 1650 1665
umhocm 9 25 C YSI 132 131 128 1131 1140 1150
average values Beckman shortBeckman long = 075
Beckman shortYSI = 11
106
Appendix D
Computer program Flow Chart
107
F1g 33 Computer Program Flow Chart-
1TpoundR MAP TCO
NEWPER
WEWSTP CZAX
HEWIT TRANS TCOF ROW COLUMN
Yes
Yes
108 The following is a description of the USGS two-dimensional computer
program Iterative Digital Model for Aquifer Evaluation updated
December 1972 by P C Trescott The program written in Fortran
consists of a MAIN program and six subprograms or subroutines which
themselves are organized into subprogram sections The subroutines and
their sections are listed below
MAIN Program
DATAIN (subroutine) COEF ITER (section) CLAY MAP TRANS NEWPER TCOF
ETRATE COMPUT STORAG
NEWSTP LEAKAG NEWIT1 NEWITO CHECK ROW CWRITE COLUMN STEADY PRNTA OUTPUT DRY BLOCK DATA
The program begins in the MAIN program which controls the sequence
of passage to the subroutines Sequential steps are described in the
program as shown in the flow chart of Fig 32 Emphasis is placed on the
steady state confined aquifer case as applied in this study First data
input is read in the DATAIN subroutine This data includes transmissivities
or permeabilities starting heads storage coefficients and grid spacings
Nodal transmissivity values are then computed for the water-table problem
in the TRANS section (COEF subroutine) This procedure is necessary here
because the subsequent routine for computing iteration parameters (ITER)
keys on nodal transmissivity values which would not have been input to
the water-table problem In the water-table option these would have been
109
computed from given bedrock and water-table elevations to obtain the
saturated thickness component of the transmissivity calculation In this
study water-table option was not used and the transmissivity values were
input directly The program then passes to the ITER section (DATAIN
subroutine) to compute the iteration parameters which expediate or even
cause convergence Next the MAP section (DATAIN subroutine) is utilized
to initialize data for an alphanumeric map if this was requested in the
input options Transmissivities are then computed for the confined
(artesian) aquifer case (water table not specified with input options)
in the TCOF section (COEF subroutine) These coefficients are harmonic
mean values of adjacent nodal transmissivities weighted by grid sizes
Time parameters and pumping data for a new pumping period are then read
in the NEWPER section (DATAIN subroutine) followed by entry into the
NEWSTP section (COMPUT subroutine) which calculates the size of the
time step Leakage coefficients (hydraulic conductivity of the confining
bed divided by confining bed thickness) are next computed in the CLAY
section (COEF subroutine) if leakage was specified in the input data
which was used in this study
A new iteration is then initiated in sections NEWITO (COMPUT
subroutine) NEWITO saves the current head values and compares them to
the updated head values for determining closure This is followed by
nodal transmissivity values being computed for the water table or water-
table artesian conversion problem Transmissivity coefficients are then
computed for the water-table problem in TCOF (COEF subroutine) Total
head values are then computed with the alternating direction implicit
procedure using the Thomas algorithim first along rows in the ROW section
110 and then along columns in the COLUMN section both in the COMPUT subroutine
Then if a solution is not obtained (because the error criteria for
closure is not satisfied) the MAIN program branches back to NEWIT1 subshy
sequent sections TRANS TCOF ROW and COLUMN repeatedly until a
solution at the particular time step is achieved NEWIT1 increments the
iteration counter and is immediately followed by NEWITO The program then
moves to the STEADY section of the COMPUT subroutine to check if the
closure criteria for steady state has been satisfied Output is then
printed in the OUTPUT section of COMPUT if steady state has been reached
or if the particular time step is designated for output
The program then branches back to NEWSTP (COMPUT subroutine) and
moves through the subsequent routines until the last time step in the
pumping period is reached Output is then promoted in the DRY section
of COMPUT if specified in input data If the last pumping period in
the problem has not been reached the program branches back to the
NEWPER section and moves again through subsequent sections otherwise
the program will terminate or start a new problem if one follows
This study was simulated as a steady state problem which can be
simulated by setting the storage coefficient of the aquifer and the
specific storage of the confining bed to zero and using one time step
of any length
111
Appendix E
Computer Data Sheets
RGSEA
10 ROSE HILL LANDFILL MODEL 20 30 40 LEAKAGE 50 60 70 CHECK 80 90 100 HEAD 110 120 1 23 IQ 100 5 001 37E-OU 0 130 100 001 0 0 1 4 0 - 1 - 1 1 - 1 - 1 i i i i i i 1
ISO 1 10 0 1547E-05 01 10 1 1 160 04642 200 200 1 1 i it
1QO 190
CARDS I THROUGH 19 - CODING SHEET
CHEAD
100 110 120 130 131 132 140 141 142 150 151 152 160 161 162 163 164 165 170 171 172 173 174 175 176 177 178 179 1BO 101 190 191 192
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 539
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 58
25
25
25
25
25
25 621
25
25
25
25
25 662
25 25
25
CARD SET 2 - STARTING HEAD MATRIX (FT)
193 194 IVb 196 197 190 200 201 202 210 211 212 220 221 222 223 bull 224 225 230 231 232 233 234 235 236 237 23B 239 240 241 250 251 252 253 254 255
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 23 25 25 25 25 25
25 25 - 25 25 25 25 25 25 25 25 25- 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 - 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25
25 25
25
25 25
25 25
25 25
25
25 25
25
25 25
25
25
25
25 25
25 25
25
25 25
25 25
25 25
25
25
25 25
25
25 25
CARD SET 2 - STARTING HEAD MATRIX (FT) - continued
STORC 1512 FRI 19 FEB 82
100 110 -1 -1 - 1 - 1 0 0 120 130 140 ISO 160 170 100 190 200 210 220 230 240 230 251 260 261 262 263 270 271
CARD SET 3 - STORAGE COEFFICENT
LEAK
100 110 120 02 130 _ 18 02
I ltu 18140 025 150 02015015015 19 deg25
02 160 022 bull-laquo- J1 5 j 1 z laquo- l^
170 015 180 016 laquo02
190 016 OE025
200 02504019022021025 2 5 i S lt03 0252i2 n
230 030 deg23 deg2 deg2 deg2 -02023023 240 022 250 022025025 02
027043 013025
30() 025025025 310 025031 320 024025
CARD SET 5 - AREA OF STEAMBEDAREA OF NODE
120
Appendix F
Bibliography
121 BIBLIOGRAPHY
1 Agpar MA and 0 Langmuir Ground-Water Pollution Potential of a Landfill Above tne Water Table Groundwater V 9 No 6 1971 pp 76-96
2 Allen William B Hahn GW and RA Brackley Availability of Ground Water Upper Pawcatuck River Basin Rhode Island USGS US Government Printing-office GS 66-624 19bb
3 Annual Book of ASTM Standards Part 31 Open Channel Flow Measurement of Water and Waste Water by Weirs D 2034-68 1975
4 Annual Book of ASTM Standards Part 19 Infiltration Rate of Soils in Field Using Double-Ring Infiltrameters D 3385-75 1975
5 Baeaecner MJ and W BacK Hyarogeological Processes and Chemical Reactions of a Landfill Ground Water V 17 no 5 1979 pp 429-437
6 Beck WW Dunn AL and Grover H Emrich Leachate Quality Improvements After Top Sealing1 8th SHwRD MERL Symposium 1982
7 Beckman WK Transient Modeling For Estimating Sustained Aauifer Yield master thesis presented to the University of Rhode Island Kingston RI 1978
8 Bhattacharya PK and HP Patra Direct Current Geoelectric Sounding Elsevier Publishing Co New York 1968 135 p
9 Bouwer H Ground Water Hydrology McGraw-Hill Book Co New Yoric 1978 p 378
10 Braids 0 Cocozza pound Fenn D Isbister J Rous P and B Yarc Procedures Manual for Ground Water Monitoring at Solid Waste Disposal Facilities Environmental Protection Agency530SW-611 Cincinnati Ohio 1977
11 Cartwright K and MR McComas Geophysical Surveys in the Vicinity of Sanitary Landfills in Northeastern Illinois Groundwater V 6 no 5 1968 pp 23-30
12 Cartwright K and Fd Sherman Jr Electrical Earth Resistivity Surveying in Landfill Investigations Reprinted from Proceedings of ohe lOtn Annual Engineering and Soils Engineering Symposium Moscow Idaho 1972
122 13 Clark TP Survey of Ground-Water Protection Methods for
Illinois Landfills Groundwater V 13 no 4 1975 pp 321-331
14 Dunne T and LB Leapold Water in Environmental Planning WH Freeman and Company San Francisco 1978
15 Faro DG Upgrading Hazardous Waste Disposal Sites Remedial Approaches US Environmental Protection Agency500SW-677 Cincinnati Onio 1978
16 Fenn DG Hanley KJ and TV Degeare Use of the Water Balance Method for Predicting Leachate Generation From Solia Waste Disposal Sites US Environmental Protection Agency530SW-lfa8 Cincinnati Ohio 1975
17 Geisser 0 An Electric Analog and Digital Computer Model of the Chipuxet Ground Water^ Aquifer Kingston Rhode Island master thesis presented to the University of Rhode Island Kingston RI 1975
18 Hahn GW Groundwater Map of the Narragansett Pier Quadrangle Rhode Island Rhode Island Water Resources Coordinating Board GWM 5 1959
19 Hemsley William T Koster C Wallace Remedial Technique of Controlling and Treating Low Volume Leachate Discharge USEPA National Conference on Management of Uncontrolled Hazardous Waste Sites Oct 1980
20 Hughes GM RA Landon and RN Farvolden Hydrogeology of Solid Waste Disposal Sites in Northeastern Illinois Final Report to US Environmental Protection Agency PUD SW-l^d Cincinnati Ohio 1971
21 Keller GV and FC Frischknecht Electrical Methods in Geophysical Prospecting Pergamon Press New YorK NY 19bb
22 Kelly WE West Kingston Landfill An Evaluation of Its Effect on Ground-Water Quality Rnoae Island Water Resources Board Water Information Series Report 1975
23 Kelly WE Geoelectric Sounding for Delineating Ground-Water Contamination Groundwater V 14 No 1 1976 pp fa-10
24 Kelly WE Ground-Water Pollution Near a Landfill ASCE Environmental Engineering Division Journal V 10 No EE6 Dec 19b pp nay-nyy
25 Kelly WE personal communication January 1982
123
26 Kelly WE and OW Urish A Study of the Effects of Salt Storage Practices on Surface ana Ground Water Quality in Rhode Island NTIS FHWA-RI-RD-8001 1981 54 p
27 Kimmel GE and OC Braids Leachate Plumes in a Highly Permeable Aauifer Groundwater y 12 no 6 1974 pp 388-393
28 Klefstaa G Senalein LVA ana RC Palmauist Limitations of the Electrical Resistivity Method in Landfill Investigations Groundwater V 13 No 5 1975 pp 418-427
29 Landon RA Application of Hydrogeology to the Selection of Refuse Disposal Sites Groundwater V 7 no b 19b9 pp 9-13
30 Lang SM Bierschenk WH ana WB Allen 1960 Hyaraulic Characteristics of Glacial Outwash in Rhode Island Rhode Islana Water Resources Coordinating Board Bulletin No 3
31 LeGrand HE Patterns of Contaminated Zones of Water in the Ground Water Resources Research v 1 No 1 1965
32 Palmauist R and L Sendlein The Configuration of Contamination Enclaves from Refuse Disposal Sites on Floodplains Grouna Water v 13 no 2 1975 pp 167-181
33 Pinder GF A Digital Model for Aauifer Evaluation Techniaues of Water Resources Investigations of the US Geological Survey Bk 7 Cl 1970
34 Purushattam D Tamxe GR and CM Stoffel Leachate Production at Sanitary Landfill Sites ASCE Environmental Engineering Division Journal V 103 no EE 6 Dec1977 pp 981-988
35 Remson I Fungaroli AA ana AW Lawrence Water Movement in an Unsaturated Sanitary Landfill ASCE Sanitary Engineering Division Journal v 94 no SA2 April1968 pp 307-316
36 Rosenshien JS Gouthier JB and WB Allen Hydrologic Characteristics and Sustained Yield of Principal Ground-Water Units Potowamut-Wickford Area Rhoae Island USGS US Government Printing Office GS 67-324 1968
37 Roux PH and B Vincent Electrical Resistivity Evaluations At Solid Waste Disposal Facilities US Environmental Protection Agency SW-729 Cincinnati Ohio 1978
124
38 Salvato JA Wi lk ie WG and BE Mead Sanitary Landfill Leaching Prevention and Control Water Pollution Control Federation Journal v 43 no 10 Oct 1971 pp 2084-2100
39 Sawyer CN and PL McCarty Chemistry for Environmental Engineering McGraw Hill 1978
40 Stellar RL and P Roux Earth Resist ivi ty Surveys - A Method for Defining Ground-Water Contamination Ground Water v 13 no 2 1975 pp 145-150
41 Todd OK Ground Water Hydrology John Wi ley and Sons Inc New York 1959
42 Tolman AL Ballestero AP Beck WW and GH Emrich Guidance Mannual For Minimizing Pollution From Waste Disposal Sites US Environmental Protection Agency-500SW-677 Cincinnati Ohio 1978
43 Trescott PC Iterative Digital Model for Aauifer Evaluation US Geological Survey Open file report 1972
44 University of Rhode Island Academic Computer Center CalComp Contouring Manual
45 Warner DL Preliminary Field Studies Using Earth Resistivity Measurements for Delineating Zones of Contaminated Ground Water Groundwater v 7 1969 pp 9-16
46 White EF A Report to the Town of S Kingstown Utility Survey Engineering Corp 1967
47 Zohdy AAR A Computer Program for the Calculation of Schlumberger Sounding Curves Over Horizontally Layered Media Using the Method of Convolution US Geological Survey Denver
48 Zohdy AAR Eaton GP and DR Mabey Application of Surface Geophysics to Ground-Water Investigations Technidues of Water-Resources Investigations of the US Geological Survey Book 2 Chapter 01 Washington US Government Printing Office 2401-02543 1974
5
a 03
N lo ^ gt
laquo c 2
mdash w
3
X o ^
3 O L
o CO
0 opound E bullo
0
co
c
o0
uj ^
0 o o c
o $ bullA
E c o
w
bullo t_hraquo9 O
_OplusmnJ ca
u
pro
ve I 51 H
bullo 0gt
UJ _c e poundbullo Mzbull w gt 0
laquorege cc
0gt -^^ o a5 raquobull bullo o sect 3 mdash laquoo o wcz _
3Ogt c $c o_ X
aw e 05 0 (0 3 bullo
o a 2 2 u
hydraulic properties and the subsurface geometry enable estimates of
ground-water outflow to be made Streamflow measurements were used
to verify these outflows Contamination levels using specific
conductance measurements as an indicator were measured in wells
streams and observation holes to help delineate the extent ana
degree of contamination An electrical resistivity sounding was
conducted in a known contamination zone
The primary objective of tnis study is to determine flow
patterns in the vicinity of the landfill ana recommend possible
actions to contain or minimize the impact of the contamination In
oraer to fully evaluate these goals the aforementioned parameters
were input to a computer model to produce simulated flow patterns
under different conditions The simulated present conditions were
matched with field water table and stream flow measurements to
calibrate the model A series of simulations were then run to
evaluate flow conditions before the excavations anaor landfill
existed Remedial measures such as reducing recharge to the
landfill and implementing a slurry wall to blocx off leachate flow
to endangered wells were simulated to evaluate their effectiveness
Based on this analysis recommendations are made as to how to
minimize leachate production ano best alleviate the immediate danger
of the contaminant plume spreading to unpolluted domestic supply
wells
background
The South Kingstown landfill is in a geologic setting that is
very similiar to the nearby West Kingston landfill This is located
about 3 miles west of the South Kingstown landfill and has been
studied to assess leachate effects on groundwater quality using
specific conductance as an indicator of contamination levels
(222ltt) Both sites were located in abandoned gravel Quarries which
were filled in with refuse to create the landfill
In the literature numerous authors have shown that the character
of contaminant plumes from landfills are largely dependent on the
local geology and geohydrology A study on Long Island (27) in
similiar glacial material illustrates that the Quantity of flow is
dependent on the hydraulic conductivity of tne aauifer the
hydraulic gradient and the vertical cross-sectional area of the
aauifer it flows through This is expressed as Darcys Law (41)
Q = KIA
wnere Q = flow quantity
I = hydraulic gradient
K = hydraulic conductivity of the aauifer
A = vertical cross sectional area of the flow area
Specific conductance was used as a contaminant tracer to show that
the plume from the landfill flowed downgradient and vertically
through the full thickness of the aauifer A study in Iowa (32)
indicates that the size ana shape of the contamination outflow from
a l a n d f i l l can be predicted from existing geohydrologic conditions
and that the horizontal shape of the outflow extends downgradient
8
from the source and parallel to ground-water flow lines Other
parameters which control the extent of the contaminant plume are
dilution and dispersion in the aquifer and the adsorption properties
of the aauifer material (31)
The amount of leachate generated depends largely on the amount
of water that infiltrates through the landfill to increase tne water
content of the refuse in the landfill The precipitation recharge
that percolates down through the unsaturated zone to the water table
moves in a vertical direction (35) Surface runoff soil moisture
storage losses and evapotranspiration account for tne precipitation
that is not transmitted tnrough the unsaturated zone of aeration
(3315) Upon reaching the saturated zone the water enters the
ground-water flow system Ground-water mounding has been reported
in landfills due to the decreased hydraulic conductivity of
compacted refuse relative to surrounding aauifer material (20)
Chemical processes within the landfill leachate outflow and
surrounding soil cation exchange capacity relative to water duality
of the surrounding aduifer have been studied in Pennsylvania (1) anu
in Delaware (5) A procedures manual for ground-water monitoring at
solid waste disposal facilities was developed by the US
Environmental Protection Agency (USEPA) (9)
Several reports have been written that investigate site
selection design criteria and remedial measures to correct
leachate problems (29) A survey of ground-water protection methods
for landfills in Illinois studies relationships to the water table
theory of liner installation and monitoring devices (13) Sanitary
Landfi11-Leaching Prevention and Control presents a review of
preventative methods such as means to minimize infiltration
interception of ground-water and other pollution control measures
(2 37) A study in Pennsylvania on actual measures implemented to
collect and treat a landfills leachate discharge presents a site
specific study (19) Leachate Quality Improvements After Top
Sealing1 shows that by minimizing infiltration at a landfill in
Connecticut the outflow leachate water quality can be improved
dramatically and contamination plume reduced significantly (6) The
most comprehensive reports on remedial approaches to upgrading waste
disposal sites and ground-water protection methods have been
compiled under USEPA contract (1542)
To assist in evaluating remedial measures the US Geological
Survey (USGS) computer model Iterative Digital Model for Aduifer
Evaluation was used It was originally developed as a model for
simulating two-dimensional aauifer problems (33) It had been
updated since its original development to accomodate different
options (43) This model has been applied to glacial outwash
regions in Rhode Island (717)
10
Description of Study Area
A map of tne landfill area (Fig Z) was obtained from tne town
of South Kingstown The excavation to the west of Rose Hill Roaa
the landfill area directly to the east and the presently operating
area to the east of the central stream comprise tne overall study
area This study will concentrate on the west landfill area whicn
has recently reached capacity and been closed to further dumping
This site received mixed refuse for the past 15 years The depth of
the excavation where the landfill presently exists was approximately
to bedrock in some places Tne exact depths of landfill material is
unknown
The landfill cover has been graded and sloped generally eastward
to convey surface runoff to the eastern side A sandy soil that was
excavated locally was used as tne cover material The northern
section has a vegetation cover and the recently filled southern
section has been seeded and mulched The six monitoring wells W
NW NE EC SE SC were placed by the town of South Kingstown to
provide water quality information
Referring to Fig 2 the west excavation stream drains the area
created by the excavation to the west of Rose Hill Road and flows
throughout the year The central stream drains a small watershed
area which lies to the northwest of the landfill and drys up during
part of the year These streams flow into the Saugatucket River
which flows throughout the year and is larger than the west and
central streams combined
11
The USGS Groundwater Map (18) was initially consulted to proviae
information on the ground-water flow patterns (Fig 5) and the
geology of tne area (Fig 6) The surficial geology borings and the
vertical geologic cross-section at the base of the study area
indicate shallow water table and bedrocic and a nearly constant
saturated thickness (18) Boring logs at the W well ana a point
approximately 150 feet south of it indicate glacial outwasn material
which is primarily sana with a trace of gravel over bedrock at a
depth of approximately 33 feet Borings at the east landfill area N
and S monitoring wells indicate the same aquifer material
(Appendix B)
The ground-water map developed by Hahn is taken as
representative of conditions existing prior to the excavation of the
I l andfill (18) This indicates water-table contour lines that run in i
a general northeasterly direction This means tnat flow was
originally in a southeasterly direction However contamination of
domestic supply wells on the west side of Rose Hill Road has
occurred (Fig 3) strongly suggesting that the original flow pattern
has been altered by the excavation to the west of Rose Hill Road and
the landfill to the east of it Domestic supply wells were formerly
located directly to the west of Rose Hill Road but were aoandoned
when they became contaminated from landfill leachate New wells
were located to the south and west away from the contaminant plume
of tne landfill In addition a well located at the northeastern
corner of the landfill was contaminated and a replacement located to
the east of Us former location on tne opposite side of the central
12
Legend scale 124000
mdash-40 mdashground-water contour elevation
Fig 5 Ground-Water Map
13
Legend feet
TILL
Fig 6 Geology Background Map
14
stream This second wel 1 also became contaminated Domestic supply
wells located near tne northwestern corner of tne landfill and
approximately 300 feet south of it nave remained uncontaminated
These well locations serve as an indication of tne extent of the
landfill contamination which is largely dependent on the groundwater
flow patterns To furtner investigate this problem and provide
substantial information on which to base the geohydrologic analysis
field studies of the area were conducted
15
Field Studies ana Procedures
A map of the lanafill and an aerial pnotograph of the area were
obtained A tracing of these maps superimposed upon another
delineates stream landfill and monitor well locations (Fig 2)
The field investigation concentrated on the west landfill area ana
its aajoining streams ana monitor wells The east landfill area and
the three monitor wells in that area are induced in the latter
phase of the study in oraer to expand the model area
A traverse which establishea tne monitor well elevations was run
using a Carl Zeiss level These were originally sitea in by the
town of South Kingstown using a local USGS reference datum number 40
(18) The wells of known elevations then served as benchmarks for
referencing adjacent stream elevations This in combination with
the depth to water table measurements at each well enables tne
water-table surface geometry of the area to oe visualized
Water-table measurements of the west landfills wells were recordea
over a ten month period to record fluctuations (Fig 7 Table 1)
The east landfill areas wells were monitored for a five month
period Using a given water-table condition a ground-water map was
developea of the area (Fig 4) This indicates an outflow from
the landfill primarily in a southeasterly direction and partially
in a southwesterly direction
Additional bedrock and water-table information was ootainea by a
seismic refraction survey at several locations along the landfill
perimeter A Bison Model lb70C Signal Enhancement Seismograpn was
used to maxe the surveys Lines were run (to a length of kOO feet)
16
17
w s p bdquo S bdquo s S S a laquolaquo _
s 2 8
V
r bdquo
3 s a
-R s
S
S 3
t
raquobullraquo
S
5
K
r
~
3
K
pound
7
S
bdquo3
C 5 S
shy raquo S s
1 3 s 3 2 5 ^ bull
5 m
s o
^ 3
raquo
--
R bull 5
s pound J O s
5 a 3 7 3 m
5 s a ^
iraquo a s rlaquo
M ^
^ c o 2 5 s 3 a S R
rd 3 y a O =J
^ bdquo
JJ s s 3 bull ~ I
~ s 5 3 a s a
(Ogt (U
2
-t =
r s s in
5 y
a s
5
3
s
5 a
^ a
3 a 51 a bullbull
sj 5 Ml
3 a bull
s raquo
a
0)
0
^ mdash
a j -
-3
C
g S
S
bull a
-
~ 3 o
2 s s 3 a bdquo s s $ Al s
(1) = $ s 3
S
c a a
3 e 5 s N s S a - 3 = s s a 5
a s s - 3 S shy
4
0
a s
bdquo tfH
bdquo
3 a
bdquo
s a
e bullfl s i s s a s a
3 nt
s s 3
g laquo s3 a
~ J s 2 a s o s S s 3 a a j laquo s o s
3 bull laquobull
2 a 7 3 a 3 a ^2
s mdash 5i o
bull bull
mdash
3 o
ss a
fc mdash
3 1-sect m ishy n
18
in both directions to provide a check and permit accurate estimates
of the depth to bedrockThe seismic results allow approximate
interpretations of the depth to the water table and bedrocK thus
permitting an estimation of the saturated thickness Ground
elevations at the location of the seismic surveys were determined
from a topographical map and field siting From this information
water table ana bedrock elevations estimates were made Bedrock
contours are listed in Fig 8 In addition a table which
summarizes the seismic refraction results for the unsaturated
saturated and bedrock layers velocities and depths at each survey
location is presented in Table 2
Scream gauging stations were established on the two streams
bordering the west landfill (Fig 9) Three stations were placed on
the central stream These provide information on the influent or
effluent condition of ground-water flow in the upper sections of the
stream and ground-water baseflow from an area adjacent to the
landfill into the stream (Table 3)
The stream gauging stations used were 90deg V-notch weirs The
weirs located in the SE and SW positions were placed in the
streamoea with a liner of plastic upstream to minimize underflow
The weirs located in the NW and E positions were cut to fit in
recesses of concrete culvert pipes Concrete plywooa interfaces
were coated with roofing cement to minimize bypass flow Upstream
water pressure and a snug fit hold the plywood sections in place
All weirs were implaceo according to AigtTM reouirements and flowrates
calculated using the standard 90deg V-notch formula (3)
19
N
seepage West observat ion Landfill hole
Area
Legend landfill limit excavat ion limit
copyWNWNEECSESC monitoring well locations
= = = unimproved road -- WNES-number
seismic refraction locations
-40shy approximate bedrock contpur elevation
feet
Fig8 Seismte Survey Location
20
c ^-^ c4j ^laquoc in -=r 3shyjj bull pn f- 4-gt bull in in OjJ bull bull a jo bull bull O JJ
co CM o on on CO CM CTNVO VO co CM o on on Q gt_x rH oj on a oj on a - rH oner
rmdash on sr i i
M z Z
gt gt gt
X-N CO laquomdashv CO CO bull igt gt bull
1 gt fc^gtgt bullbull ^ ^ ^
C 4-gt O t igt O J- 4J O H m o o o 3 bullH CO O rH in 3 bullH co vo o in 3 ~ 1 i-k -i ^trade fj rj ui ij o CO o n o rH =r co o n vo vo vo co o bullv O O O
O raquo On-3 rH O -bull- rH ON in _ IH in oj - rH bull rH VO OrH bull rH On ON pH d)u CO -UCO 4J OJ CO 4-gt gt
C mdashbull gt CM gt CM H-l O CO
v- ^^ N C 0
bull0 N CO
4-5 -0 _c^gt in in CO CO
C x~ c -^ t-oo in i 4J j_gt 41 4J bull 9 bull bull 4J bull
o j ON O O 3 (0 O4J O ON ON QJJ t~-^3- OJ 4-gt L
CO CM trade CO CM rH rH OJ co CM oj on Q ^ _ CO 3~Q-- n 45 Q mdash OJ OJ OJ C (0
1 11 3 nZ 2CO
gti gt gt CO CO CO ^-x m -s CO
rH rH ^ ro^^ bull gt bull ^ igt gt bullgt gtgt bull r O -Q 4Ji JJ O 5- JJ O pound- ^ O 4) oj o on (0 CO
3 bullH CJ O O in 3 bullH CO Cmdash VO on 3 pound-laquo H CO o n in inco co o n ma- r co g^ 5sect^ o
o rH on oj O bull- rH ONCO L O_ rH OJ VO M
rH bull rH =t rH bull - OJ T CO CO M CO 4-gt rH CO -U rH CO 4-) s
uits
CO 4-gt 4-5 T3 gt CM gt CM gt CM cc CO CO CO
3 3gt oa tlp^ CO O CM O gt 4J O 40 i 3 r+ k C pound JS
CO pound
^^ s -bullgt cmdash on poundZ VO CTI trx 4J 4J 4J
) bull bull bull Q Q Q Q4J 3shyc O-JJ CTgt OJ OJ Q-IJ inco on CO CO CO o co CM oj on co CM oj on co CM on
Q Q QON^ Q bullH Q^
rH rH 4J rH
O bullraquo L Z bull CO CO CO
i gtgt rH oj on gt tgtshyCM ^ cO^-s CO ~ CO
CO CO J X fc^_ bull^gt bullgtgt bull gt gtgt bull gt CO
j_ jJ O pound- Jj -P O Li deg =fObullH co on f- ^ 3bullH CO CO O in 3bullH CO
g^ -^2
poundsect HO
eis
mic
3 CO in in in in in in co o n co o n
o -^ r oj in O rHCO CO rH bullrH bull rH =T OrH bull rH OJ f-CO 4J bull- CO 4J rH O0) J-)
gt CM gt CM gt CM 4J
CO N_^ m^
bull OJ
t t poundshyCO CO CO CO rH J3 gt r-t oj on gt r-i oj on gt gt r n o j o n
lto co lto CO T bull ii-4 laquomdash bullmdashH
bullo CO L L 0)
CM CO cc
21
N
545-594
seepage observation
hole West Landfill
0NE I47-509
Area
Weir 45
i487-531
0 EC Al3-467
Legend bullmdash landfill limit -bull---excavation limit r-s stream
copy WNWNEECSESCSEN monitoring well locations
= = = unimproved road
Weir location and elevation
feet
Fig 9 Weir Locations and Wate r Level Ranges
22
JT NO
S shy S
O
bull ry m
oa
NO
(M raquo 1 03 or NO m
JT O O raquo
O NO 03 (j
PW tn in ^4 fraquo
m CN) f O O (M Oj
mdashraquo 3 M
s cshy -raquoraquo
o in in ^
rjO
laquobull NO ON
o bull-lt ^
H fy (NJ
tjgt
1 4 03 O
o
o
03 CM
in0
0
7 raquo
9gt
IM i iev NO
i in
i ru
i 0 rsi -or^
sO NO
CO O
03 raquo
1 O3
pound o ro CNJ
03
tn B OJ
o 03
m oi
NO
(M
r
(M
CO i M 03
m N ltn ~+ ltM -
QJrH
O M O ^ ^r-
oo m
8 a
m
^ NO
8 fNl
rshy03n
m - in
o laquoO
bull3 as m o 03 03 4
i O
i ^
shy
O
ltM bull^
ON f tn H 1 4 raquo4 i-4 H P-t
^^ lt-l
r-laquo
^ 1 1 1 1
pound raquoraquo O)t o gtz
bull bull ltbull
lt2
1 pound OJ
3 oi g bull
pound
1 pound laquolt bull
3 bull o a
pound
5 laquo15
f bull 3 Jl s
5bull 1 5
23
A field study to determine the infiltration capacity of a
section of tne landfill topcover was conaucted A modified version
of a double ring infiltrometer was used to study infiltration rates
(4) The cylinder diameters useo in this study were 8 inches and 18
inches A constant head of 6 in was maintained in the
infiltrometer and rates of infiltration were determined Tnese
results and an analysis of surface infiltration into the landfill
are included in tne analysis and discussion section
Specific conductance levels in the monitoring wells in the
streams bordering the landfill and at observation holes near the
landfill were measured (Fig 10) This is a good indication of the
mineralization of water (39) Specific conductances were measured
intermittently over the ten month period to develop a picture of the
extent and degree of contamination in the wells (Fig 11 Taole4j
and in the surface contamination monitoring locations (Fig 11
Table 5) A comparative standardization of the Beckman (short and
long probes) and YSI specific conductances is in Appendix C
A surface electrical sounding using the Schlumberger array was
conducted adjacent to Rose Hill Road at the R-l location (Fig 12)
in an attempt to delineate the vertical extent of the contamination
zone Well W was used as a centerpoint and a reference for
water-table depth pore water conductivity and depth to bedrock A
Schlumberger array electrical resistivity sounding was also
conducted in an uncontaminated area at tne R-2 location (Fig 12) to
provide a comparison background interpretation A seismic
refraction survey N-4 was conducted at the same location (Fig 8J to
24
N
excavat ion
Seepage West observat ion Landfill hole
Area
Stream 1 Seasonal observation 0 EC
hole
East Stream2
Legend sw Weir landfill limit j--1--^ excavation limit
copyWNWNEECSESC monitoring well locations
== unimproved road
feet
Fig 10 Surface Contamination Monitoring Locations
25
8000T
7000
O bull U) W6000
Legend
0 sc A NE O W
A SE O N W
a EC
1 O N D J F M M
Time months Flg11 Flucuatlon In Specific Conductance in Wells
26
Table 4 Specific Conductances in Wells (pmhoscm at 25degC)
West East Landfill Landfill
Date NW NE EG SE W SC N E S
81581 851 938 236 2356
102981 171 3268
11381 3268
111081 304 988 1100 258 3800
111481 426 2736 1216 186 4560
111781 304 3610 433 389 4560
121981 380 1406 129 103 380
1982 160 152
31582 274 760 1064 61 334 8000+ 182 53 84
52182 450 1500 1125 112 712 8000+ 175 255 150
52282 425 1320 1200 110 850 180 320 170
27
O
ct c r i c o o o o o c M o m o in CO CM unp^
3bull t- fmdash o^ co tmdash vo co in co cmdash co in a
bull bull1 1-1 trade4 rH rH^ CO 4)2
~ plusmn4J o O CM ^_
o n CO vO J oraquo 0C0M
cu rH rH rH rH rHin tmdash
3 iCM 4J
^j CO CO
E O0 ltU -H n o c E
See
pag
se
rva
t
rH O in 0 0 O O 0
O o x rH Cmdash
0 0n
cu rH mdash O tmdash X o o o o c o o o o r H r H i n o i n i n o O
bull L in oo co oo oo o cy cr o rH CM o cr ONc fcJ bullH on en m m rn c^n rH rH rH0 pound CO 3 CO
t CM0gt s o o o in rA n ^o oo in tmdash oo 0gt zr =r a- JT JT$_
T)C CO
~ E CO ^ _bdquo ltu CO g r H r n c n i n o o r H r H
vgtO ^D O ^^ ^O CO ^^ ^^ JJ 2 4) rH rHCO t
c CO
CO c 9) rH 0
CO -^ C c CO ltuo famp O trade t iH
0
bullo co n ^
oS
o ^^ bullH m
i co rn O CQ O1 CO CO 4) c2Q 3
CO
mdash^ bull cmdash CMin 1 gt rH vO vO O CTgt CO
s CTgt CO OO Ogt Craquo- tmdash cu O CO rH z 0
bull_bulllaquo
H bull L o in r in o oo in 3 rfy ff^ tir f^ CO C^~
4)bull
Z 3
^ ^ ^ ^ H r H r H r H r H rH r H C O r H C O a O C O a O a O C O C O r H i H r H CO OO - gt 0 0 ^ - gt ^ raquo - ^ ^ 1 - gt ~ gt - C O C O O O
U ^ raquo ^ - ~ raquo O ^ ^ O t ~ C O r H - r r ^ - ^ ^ JJ r H C M v O r H r H r H r H r H C M C M r H i n c r gt rH CO CM gt laquolaquo - - -^ bullmdash mdash bullraquoraquobullgt -v -v ^^
~ v O r H r H r H r H r H r H r H r H lt M C M C M CM O O r H r H r H r H r H r H r H r H r H r H r H r H rH
in rH cmdash
CO vo
CO vO
41 rH CO
CTgt rH raquo CM rH
cn CO
o 0 rn
CO cmdash
tmdash fshy
CM ao
iT rH
m
ogt ao
O o vO
CO t-
tmdash Cmdash
CM CO
rH CM
I
rH CT
O vO in
CTgt
in c^
CM ao
CM CM
in
-
bull
CO bO C bullH T3
cy ~
_
CJ E 3 ^ n c bullH
1-1
CO
^H
28
excavation
West Landfill
Area
Legend bullmdash landfill limit -bullbull--bullexcavation limit r~~s stream
copy WNWNEECSESCSEN monitoring well locations
= == unimproved road
electrical resistivity sounding
feet Fig12 Electrical Resistivity Sounding Location
L
29
allow estimates of depth to water table and bedrocic to be made
Soundings were carried out to 500 foot electrode spacings to insure
that hredrock was penetrated and to facilitate interpretation These
results and a discussion of the soundings interpretation are
included in the analysis and discussion section Schlumoerger
resistivity soundings were made using a Soiltest R-bO unit
30
Model Development
The USGS Iterative Digital Model for Aauifer Evaluation was
usea to develop steady state flow models of the study area (43) A
flow chart of the computer model and a brief explanation of the
subroutines usea is presented in Appendix D The stream locations
elevations and aauiferlandfil1 geometry and hydraulic properties
were input to the model to compute head values at each 200 foot
grid spacing node (Fig 13) The input data which is for the
existing excavation and landfill conditon is listed in Appendix E
The head values that are computed at each grid space are in turn
loaded into the CalComp plotting routine (44) where a grid spacing
is setup with the computed head values at each node The contouring
program linearly interpolates between these head values and
generates a contour map The computer simulated ground-water
contour map for the excavation and landfill is presented in Fig
14
The streams in the model generally serve as controlling boundary
conditions When using computer simulated geohydrologic models of
an area choosing the boundary conditions for the model that are the
same as prevailing conditions in the field is a critical step in
model development Extending the models boundaries to areas in the
field that have a minimum influx of ground-water across them
simplifies the proolem of calculating fluxes from outside the model
area The eastern boundary is bordered by glacial till which has a
low hydraulic conductivity estimated to be 67 ftday(2) This
contrasts to the high hydraulic conductivity of glacial outwash that
makes up the model area of approximately 107 ftday(3036j
31 N
o 9
bullO O
32
33
The Saugatucket River serves as the controlling boundary on the
east A small drainage area directly to the east of it provides a
minimal influx
Beyond the moaels northern boundary the glacial outwash valley
extends to the base of a till covered h i l l on the western half ana
on the eastern side extends along the Saugatucket stream Due to
the relatively large drainage area that lies upgradient from the
northern boundary a recharge flux eduivalent to 10 inyr over the
drainage area on the till hill and outwash area north of the model
area was input as underflow (Fig Ib) Part of this was input at
each northern boundary node Till has a lower infiltration capacity
than outwash so more of the precipitation w i l l be transmitted as
overland runoff resulting in a lower ground-water baseflow The 10
inyr of recharge that results in a ground-water inflow from the
combined till and outwash region represents an estimate that is
smaller than the 14 inyr recharge for glacial outwash areas in
Rhode Island (25)
The glacial outwash valley extends beyond the western boundary
No significant ground-water recharge flux was estimated at this
boundary A relatively low ground-water gradient exists to the west
of this which does not provide a significant flux across this
boundary Tne southern boundary is basically the outflow region for
the area and therefore would not reauire any ground-water flux into
the moael area across this boundary This boundary was set south of
the point that the streams in the model merge together Therefore
the streams which lie to the north of it are the controlling
34
scale 124000
Fig 15 Northern Drainage Area
35
boundary conditions The flux out of the downgradient outflow
region approximately eauals the influx from precipitation recharge
and boundary influxes
When tne stream configuration in the moael area are reviewed it
can be seen that they comprise a large portion of the boundary
area The screams can act as sources or sinks for water in the
model thus providing to and removing water from the aquifer The
leakance option was used in the model which provides for a confining
bed and aouifer area beneath the stream to be input
The leakance is defined as the hydraulic conductance of the
streambed divided by the streambed thickness which in this case is
taken as 1 foot The leakance value at each streambed node
restricts the flow between the aduifer and the stream The
streambed hydraulic conductivity is typically 01 the value of tne
hydraulic conductivity of the aduifer (717) The value 107
ftday was used for a streambed conductivity based on a value of
107 ftday for the aquifer The aduifer and stream hydraulic
inputoutput exchange at eacn node is calculated by initially
finding the difference between the initial field stream head
elevations and the computed head elevation values at the
corresponding nodes This head value is then multiplied by the
(Leakance value at each node) x (stream area of each node)
Therefore if the aduifer head was lower than the stream head the
stream would act as a source of water for the aquifer and vice
versa
36
Tne leaxance input at each stream node is the ratio of the
actual field streambed area in each node to the area of each node
which is 200 ft x 200 ft = 4 x 104 ft2 The west
excavations stream width is approximately 3 ft central 4 ft and
east 5 ft Therefore if tne west stream traverses the node
directly without meandering it presents a leakance of 3 ft x 200
ft4 x 104 ft = 015 Leakance and streamhead values were
input at each node to set up the stream flow parameters in the
models
A recharge value of 14 inyr over the entire area was input at
each node This represents a value of precipitation that is
transmuted into tne ground-water rather than being directly
evaporated evapotranspired through plants or overland flow
runoff The precipitation recharge flow from the stream into the
aauifer and boundary fluxes provide the model witn input flow
parameters
From analyzing the available information it was determined that
the study area lies within a glacial outwash area with a relatively
shallow bedrock The seismic survey around the landfill generally
indicates a depth to bedrock below the land surface of approximately
29-43 ft with corresponding saturated thicknesses of 19-33 ft as
seen in Table 2 This agrees with borings from tne USGS groundwater
map in the stuuy area (18j The seismic survey was run at a low
water table condition which was several feet below the high water
table level (Fig 9)
37
High water-table saturated thicknesses were used to develop
model parameters For the purpose of this model study the saturated
thickness was set at 30 ft except in the vicinity of well W where
there is a bedrock high (Fig 8) At this location a high water
table saturateo tnicxness of 8 ft was estimated In tne vicinity
the seismic survey was conducted the bedrock elevation at this
location is the highest and the saturated thickness the least Tnis
can be seen by an east-west cross section of tne landfill (Fig 16
The boring log for well W indicates a sand trace gravel outwash
material (Appendix B) Boring logs at the eastern landfill area N
and E indicate similar material On this basis the hydraulic
conductivity was estimated at 107 ftday (3036) Witn the
exception of the landfill and the bedrock hign areas the
transmissivity values were set at 107 ftday x 30 ft = 3210
fto day From the literature the hydraulic conductivity of the
landfill material was estimated at I ftday (19) The
transmissivity of the landfill material in tne nortnern section was
estimatea at 1 ftday x 30 ft = 30 ft^day or approximately two
orders of magnitude lower than the outwash In tne landfills
southern section the original excavation was not as deep as in the
northern parts The landfill material was estimated to makeup only
one half tne saturated depth the remainder being the original
glacial outwash material (Fig 17) Therefore the transmissivity
at the southern end was estimated at 15 ft x 107 ftday + lb ft x
1 ftday = 1620 ft^day These values were graded into the 30
ft^day values at the landfills northern halfway point These
38
were input as transmissivity values to the model at their respective
locations This model did not use the water taole option so
water-table fluctuations did not affect the transmissivities
39
O
-8 Oi0
co o
CO
o Oin
3
O or
bullo c 10
ogt o laquorf o
c o o e 0i
CO to o k O
co CO LU I
09 O
bullo c 01
CO
C9
UO|JBA9|a
40
o ltD
a o co
o10
o o
C O
coI co co O w O
o CO I
JC
l_ o Z
bullo c 09
CO
oin uo|BA8|a
Model Calibration
A simulation was run using the initial estimates of stream
parameters aquifer and landfill hydraulic conductivities
transmissivities boundary and recharge conditions to approximate
water taole conditions in tne fiela Initially the existing
condition of the excavation area to tne west of Rose Hill Road and
the landfill to tne east were modeled in order to calibrate the
model to current field conditions as shown on Fig 4 The simulated
well values (Fig 14) fall within tne range of field values (Fig
9) The resulting contours also provide an approximate matcn This
can be seen by comparing Fig 4 with Fig 14 An additional check
was to match the flow loss and gain in the streams between tne weirs
in the central stream which w i l l be discussed later The
simulated flow value from the excavation drainage stream is the same
as that measured at the SW weir location Having calibrated the
model by approximately matching well water levels nead contours
and scream flow values different field conditions and possible
remedial measures can be simulated
When the model grid was laid out over the study area as viewed on
Fig 13 the stream configuration rarely traversed the grid nodes near
their central axis When the stream locations were input to the
computer the information was documented as crossing the central axis
of the grid nodes The result of this is a slight aberration when
the actual stream configuration is laid over the computer graphics
head contour output The streams dont always cross the groundshy
water contour at the logical location Rather than modifying the
actual stream configuration to adjust then to the computer output
their actual locations are presented
42
Simulations
i The primary focus of the computer modeling is to analyze flow
patterns under changing conaitions in the near vicinity of tne raquo
landfill The study areas overall flow patterns as they exist
today are first presented in order to realize the lateral east-west
head contour lines between the stream that directly borders the
landfill on the east side and the SaugatucKet stream (Fig 14)
This indicates a general southerly flow direction in that area As
different conditions are modeled these contours generally maintain
their east-west orientation In order to facilitate interpretation
of flow patterns in the near vicinity of the landfill flow patterns
to the west of the stream that borders the east side of the landfill
r are presented in the subseauent models
L- Natural Conditions
The results of modeling the original natural conditions are
shown in Fig 18 The excavation and stream to tne west of Rose
Hill Road and tne landfill did not exist in this simulation The
southwestern boundary consists of a drainage stream that was
delineated using an aerial photograph and stream elevations were set
using the topographical map The USGS ground-water map (18) was
used to estimate head values between the west excavation and north
streams These were input to the model as constant heads on the
models western boundary The resulting simulation generally matches
the southeasterly flow direction that is indicated on the
ground-water map (Fig 5)
A3
Legend
x-^- stream 400 = = = unimproved road
I f ee t
Fig 18 Natural Conditions
44
Excavation Without Landfill
The condition of the excavation to the west of Rose Hill Road
with its resultant drainage stream without the landfill was modeled
next (Fig 19) The extent of the excavation ana the location of
the new drainage stream were delineated using the aerial
photograph The west stream elevations were sited in the field and
used in the model The concept of a confining streamoed layer was
excluded in tne excavation drainage stream under the concept tnat no
significant organic layer had been built up within the 25 year
period that the excavation had been initiated Head values between
the west and north stream boundaries were interpolated and input as
constant head values on the northwestern boundary The west
excavation drainage stream creates a condition that alters the
natural ground-water flow patterns by creating a more southerly flow
condition the drainage stream providing a more immediate surface
outflow in that area
Landfill Without Excavation
The hypothetical case of a landfill without the excavation was
modeled next (Fig 20) The low hydraulic conductivity zone of the
landfill changes the natural flow conditions and creates noticeable
mounding This is evidenced by the decreased spacing of the head
contour lines and deviation from the lateral contour lines of the
natural conditions and higher head values (Fig 21)
45
Legend
excava t i on s t ream
400 unimproved road
f e e t
Fig19 Excavat ion without Landfill
46
Legend
landfill limit
bull - s t ream 400 copy WNWNEECSESC
monitoring well locations f ee t bullbull-bull=bull unimproved road
Fig 20 Landfill without Excavation
1
oin CM
bull
m u
0)rf
oO
bullo 9
bullo 9
o rf o o CO 1
lt0inO O
T ^ogt
c o
47
o9 aI 0)
ot_3 O laquolaquo coO bull3 OJ oX
bulla caj
CM
UO|IBAraquo|
48
Landfill ana Excavation
The condition of tne existing landfill and the excavation with
the dam is the next condition modeled (Fig 22) The ground-water
elevations used to calibrate tne model correspond to an actual high
water table condition Between the NVJ and pound weir a streamflow loss
of approximately 102 gpm occurs aoout 60 percent of this flow is
lost at the dam site which maintains a head of b-6 feet over an area
of approximately 1800 feet^ This approximates a field value of
1144 gpm influent to the aduifer between the NW and E weir on ]2
December 1981 (Table 3) From the E weir to the SE weir a net
increase in flow occurred of 74 gpm which corresponds to field
increase of b62 gpm
The surface runoff from tne landfill flows primarily toward tne
eastern side of the landfill Increases in water-table elevations
on the eastern side after heavy rains such as the 11 November 1981
storm indicates that this runoff increases outflow gradients to the
stream and therefore increases streamflow Surface runoff input is
not modeled which explains in part why field stream inflow values
are slightly higher than model predictions especially for periods
after a storm has occurred The flow from the SW weir located at
the southern end of the excavation represents drainage outflows from
that area The net flow calculated in the model was 140 gpm
which approximates field conditions of 1642 gpm on
December 9 1981
49
d f l f reg N E
shy
Legend
landfill limit -bullgt-bullgt- excavation ^-N_X- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road
-40mdash approximate groundwater contour
400
feet
Fig 22 Landfill and Excavation with Dam
50
The modeled flow patterns suggest how the various contamination
zones around the landfill have developed to their present state
They indicate a flow to both the southeast and southwest on their
respective sides of the groundwater divide Evidence of a
southwesterly contaminant flow is presented when the continued high
specific conductance contaminant level in tne observation seepage
hole is realized (Table 5 ) In addition the specific conductance
increase in the west excavation stream is evidence of an influent
contamination flow
Contamination flow to the eastern and southeastern side of the
landfill is obvious High specific conductance levels in the wells
on the eastern side (Table 4 ) a specific conductance increase
between the E and SE weirs (Table 5 ) and contamination in the NE
domestic supply well (Fig 3) present conclusive evidence of
contamination to the eastern side of the landfill
An anamalous condition that exists is a domestic supply well
located approximately 300 feet due south of the landfill remains
uncontaminated (Fig 3) Flow patterns indicate that contamination
would be transported from the landfill south to this area
(Fig 14) One explanation is that a pocket of clay at the southern
end of the landfill area was discovered in the original excavation
for the landfill (lt6) This evidently prevents leachate from
reaching this wells radius of influence
51
Summer Conaitlon
As described earlier during dry months of the year the stream
that normally borders the northern and eastern side of the lanafill
may dry up as far as a point southeast of the E well Tnis
condition existed from the 15 August 1981 to the 27 October 1981
period when streamflow commenced in the northern part of the stream
yet did not overflow the north dam until 17 November 1981 This
created the present day continuous flow condition throughout the
stream These summer conditions were modeled by removing the stream
above the aforementioned location while other conditions remained
the same (Fig 23) Summer condition well water levels listed in the
model generally match field low water table conditions (Fig 9)
Because there is no stream upgradient from the landfill to provide a
stream head and infiltration through the streambed groundwater
runoff from the area north of the lanafill is the controlling flow
input In these moaels an average recharge of 14 inyr was used
which represents a yearly average The summer recnarge conditions
are prooably lower given the effects of decreased rainfall and
increased evapotranspiration during the summer months A domestic
supply well whicn exists northeast of the landfill (Fig 3) nas a
greater potential to be contaminated from the lanafill at tnis time
than when the stream is flowing Flow patterns from the landfill
are such that during an upper stream no-flow condition groundwater
flow patterns are more in an easterly direction than in a
southeasterly direction The stream would act as a source of
infiltrated water upgradient from tne landfill and provide a
52
I ^N gt i I i j i -r- -bull- bullr -T- t- -r- i- TJ JV
bullbullT laquo ^ O - laquo bdquo xi cshy
H r^~ I -~- --^ X- = mdash x^ N
^--^ A bull O^NW -v - gt-bull Ni i I _____mdash - bull laquo l - mdashmdash 1 deg I ^ltv I C
I reg NE A
Js bull vbull A ~ - v T gt- ^ ix - N
-5Z- | N TfS lV I -bull bull iA i gt gt I ^ bullr-Ky L bull 1 _- copy]wgt-- - bull- mdash - - shy
= r Y ~mdash ltmdashA A
^^-lt A _ - - - - bull Hmdash - reg EC x ^-mdash mdash I ---mdash_mdash -t-V-^N - y
I- -bull - r x i X
V ^ 7 I -v (^~~^^r ^^^
sc Emdash-bull vV JI - - - ~ r )N y- -
X - bull r bulllt
^bull^ y y Jlaquo^ - -lt shy
T s^ lt^ ^ +^-b (
X
Legend
landfill limit j-j-bullraquobull excavat ion gt^ -x- s t ream
reg WNWNEECSESC monitoring well locat ions
= == unimproved road fee t
Fig 23 Summer Condition
400
53
constant head across tne northern section of the landfill This
would tend to orient the flow in a more southerly aowngradient
direction In addition the stream which flows adjacent to the
northeastern well could provide a source of infiltrated clean water
to it which would minimize the possible contamination from landfill
leachate
Without Dam
During tne spring scream flow condition the dam failure which
occurred between the 15 March 1982 ana 9 April 1982 monitoring
periods decreased flow to the aauifer and landfill This eliminated
the 5-6 foot head difference over a 19000 ft^ area which had
created a larger area and elevation head for infiltration to occur
The condition without the dam was modeled by reducing the area
encompassed by the dam to a 4 foot wide stream channel thus
reducing the leakance value at that node (Fig 24) The flow change
from the stream to the aduifer between the NW weir and E weir
reduced the model flow loss to 50 gpm Tnis corresponds to the 9
April 1982 monitoring period which indicates a 30 gpm loss
As compared to the previous flow loss in the upper stream
sections to the aauifer the 21 April 1982 and 22 May 1982
measurements between the NW and E weirs indicate a flow gain The
streamflow conditions have changed from an influent
stream-to-aauifer condition to an effluent aduifer-to-stream
condition that increases flow downstream
54
Legend
landfill limit j--i--i- excava t ion x-gtmdash^- stream 400
copy WNWNEECSESC monitoring well locations
= == unimproved road f e e t
Fig 24 Landfill and Excavation without Dam
55
Analysis and Discussion
In order to fully understand flow patterns and Quantify leachate
outflows at the landfill it is necessary to arrive at an estimate
of flow inputs from precipitation ana upgradient sources In the
following analysis it will be demonstrated that the rainfall input
to the landfill is the factor which controls leachate generation A
calculation using the H inyr recharge over the area of the
landfill was made to estimate the leachate outflow due to rainfall
infiltration An estimated 134 gpm is generated from the entire
landfill area Simulation of the existing conditions (Fig 24)
indicates a groundwater divide in the landfill is located
approximately at the western third Therefore approximately 23 of
the generated leachate flows to the eastern side of the landfill or
9 gpm The effect of the flow input from the upgradient stream is
evident when tne summer condition witnout the stream is viewed
(Fig 23) Without the stream to infiltrate the landfill and the
recharge and northern boundary condition as the flow inputs the
head at the northern end of the landfill drops about 5 feet from its
previous value A flow pattern from the north central part of the
landfill to the eastern side indicates a 12 feet head difference
with recharge - but with the upgradient stream a 16 foot head
difference occurs Considering the transmissivity change the
stream would increase the leacnate outflow from the landfill
approximately 43 under a low water table stream influent condition
to the aauifer This would increase leachate outflow to the east
side to approximately 129 gpm This value approximates the
56
outflow at the SE weir location during the summer monitoring period
when the upper stream was not flowing (Table 3) The outflow from
the western third of the landfill whicn lies to the west of the
ground-water divide would be approximately 63 gpm
Realizing the importance of infiltration to tne landfill as a
major influence on the generation of leachate an analysis of this
w i ll be discussed An estimate of infiltration was made using the
precipitation recora for October ana November (Appendix A) During
this time period a minimum of direct evaporation ana
evapotranspiration occured and the grouna is not yet frozen The
top cover over the lanafill is generally 05 ft to 2 ft of local
sandy soil and subsoil availability determined what was used The
top of the landfill is at an elevation of 92 ft as compared to the
ground surface at well W which is at an elevation of 76 ft
(Fig 25) This compares to the well W water level which is at an
elevation of approximately 52 ft This creates a long path for
infiltration through the unsaturated zone The topcover generally
slopes eastwara at a grade of 2-5 The west side maintains a
relatively steep slope of 10-15 ft drop within 50 ft ana the north
and eastern slopes have a more gentle slope of approximately 10 ft
within 100 ft distance An unlined surface arainage swale channels
surface runoff from the northern section of the landfill past the
NE well to the eastern side ana low area in the vicinity of the E
well This has a drainage swale to an area near the stream but
doesnt directly connect to tne stream A poorly graaed drainage
swale exists on the landfills left side The landfill material has
57
excavation
seepage observation ^
hole
Legend bullmdash landfill limit -^--excavation limit r^s- stream
copy WNWNEECSeSCSEN monitoring well locations
--- unimproved road O location of amp Inf i l t rometers O
feet
Fig 25 Infi ltrometer Locat ion and Drainage Feature
58
been placed in 10-12 ft cells and covered with 1 ft of soil at the
end of each day The material has settled differentially creating
areas for depression storage
An estimate of the percentage of precipitation that infiltrates
the landfill was made from precipitation records recorded well
elevations and an estimated specific yield for the landfill
material The volume of water that infiltrated should eaual tne
specific yield multiplied by the well water level rise Several
recharge periods were studied using this relationship Once the
percentage of precipitation that has infiltrated is determined the
percentage that is translated into runoff is simply the remaining
percentage if evaporation is neglected
From the literature for a slightly inclined slope of 2-5
typical runoff coefficients range from 10-20 in either sandy or
heavy soil (16) The landfill cover is generally sloping to the
east which creates a long path (approximately 400 ft) before the
runoff reaches the steeper slope on the eastern side of the landfill
of 15-20 The long drainage distance creates a greater time for
rainfall to infiltrate Another consideration is the actual
capacity of the soil to conauct water into the soil which was tested
in the field using double ring infiltrometers An average initial
percolation of 8 mmhr the first hour and a subseauent rate of b
mmhr occurred (Fig 26) The 8 mmhr rate compares well with
other sandy soil infiltration rates (14) Therefore if the
intensity of the rainfall exceeded a 5 mmhr rate for several hours
59
CO + 09 o
E o
CO
o Z pound C
O
C9
o DC
CO
CD CM
ogt CO N- to -4 CO CM
jq tuu i U O | raquo B J J | | J U |
60
on a poorly drained surface the additional rainfall would be
translated into runoff because the soils infiltration capacity had
been exceeded
The initial 8 mmhr infiltration rate was due to the pore spaces
in the sandy soil being filled and the subsequent 5 mmhr rate was
percolation into the low permeability landfill material The tests
were conducted in November assuming a minimal evapotranspiration
and the field capacity of the sandy soil had been maintainea
The W well was used as representative of the water elevation
changes in the landfill because it is directly adjacent to the
landfill 900 ft distant from the upgradient stream This minimizes
the effect of infiltration from the stream and maintains a high
contaminant level During periods of high runoff conditions excess
surface water ponded in a poorly graded drainage swale on the west
side and directly adjacent to the landfill This influenced the W
well at a time the contamination level dropped (Fig 11) Before
this occurence in mid-December the rise of the W well closely
matches that of the SC well and a background well SK6 which is
located outside the study area (Fig 7) Therefore it was analyzed
as a valia indication of the water level rise during the mid-October
to mid-December period The monitoring of the SC well was
intermittent due to inaccessaoility because of 10 ft extensions
being placed on the well as the refuse was being filled in arouna it
61
A high rainfall period from 14 November 1981 to 1 December 1981
was chosen for the initial study period The effects of
evapotranspiration were neglected due to the cool temperatures
experienced at this time Therefore it was assumed that the field
capacity haa been reachea and tnat any additional input to tne
unsaturated zone would result in direct percolation to tne saturated
zone During the time period 14 November 1981 to 22 November 1981
029 ft of rainfall fell and the well W rose from 488 ft to 493
ft - a 05 ft increase During the next 8 day period there was no
precipitation yet the W well continued to rise to 4972 - a 042 ft
increase The slow percolation of water through the landfill
material would account for the latent rise in the well water level
From previous reports a specific yield for refuse was estimated to
be 028 (1920) This value is dependent on the original compaction
of tne material age and resulting consolidation
During the 14 November 1981 to 1 December 1981 period 029 ft
of rain fell and the well increased 092 ft The following
relationship is used to evaluate the infiltration value and runoff
I = (Sy) h
Sy = specific yield
h = well rise
I = volume infiltrated
I = (028) (092 ft) = 0261 ft
62
The difference between the precipitation and the infiltration is
the runoff (assuming no evapotranspiration) Therefore 029 - 026 =
003 and furthermore 003029 - 13 runoff This corresponds in
the literature to a typical runoff coefficient for an inclined
surface of 2-5
Analyzing a longer precipitation period from 18 October 1981 to
1 December 1981 a net precipitation of 043 ft (accounts for
evaporation) occurred less 10 for runoff or 039 ft infiltrated
This results in a 139 ft elevation increase The well water level
actually increased 132 ft shy only a 5 deviation from the
calculated
From tnis investigation it is seen that a large proportion of
the precipitation has the potential to be transmitted into the
landfills saturated zone Exceptions are wnen heavy precipitation
periods exceed the soil percolation capacity frozen ground prevents
infiltration and direct evaporation and evapotranspiration recycles
the ponded surface water and infiltrated soil moisture back to the
atmosphere In retrospect water temperatures within the monitoring
wells could have been measured to indicate thermal effects from the
landfill on ground-water temperature Ground-water temperatures
were assumed to be 50deg F (9)
63
Specific conductance measurements serve as an indication of
contamination levels These measurements are used to trace leachate
movement which represents ground-water flow patterns Factors which
must be considered when monitoring pollutants are the attenuation of
the leachate contaminants which occurs both in the zone of aeration
and the saturated zone The former is a more complete process
Dilution dispersion and cation exchange are the primary factors
involved in decreasing leachate concentration in the saturated
zone The glacial outwash materials of southern Rhode Island do not
have a cation exchange capacity or a high buffering capacity so
attenuation is simply by dilution and dispersion (22)
The NW well consistently exhibits relatively low specific
conductance levels even though it is in landfill material It is
situated in a drainage swale and ground water elevations range from
543 to 5944 This is several feet below the upgradient stream
elevation of 64 feet which is less than 400 feet away The bottom
of the wellpoint is at an elevation of 5312 feet well into the
landfill material Infiltration from the stream to the landfill has
occurred at this location
The W well is situated on a bedrock high adjacent to the
landfill approximately 900 feet from the upgradient stream and its
water level is higher in elevation than the excavated pit (West
Observation Hole) which is 300 feet directly west The W well
maintains a contaminated level A poorly graded drainage swale to
the west of the landfill provides areas for extensive ponding and
infiltration to occur which explains the drop in conductance after
a high runoff period
64
The SC well is located in landfill material and has a
conductance of over 8000 umhos This indicates that leachate is
undiluted The oottom of the wellpoint is at an elevation of 389
feet which is situated in the landfill material
High specific conductance measurements in the west observation
hole and well W and their relative elevations indicate a
west-southwesterly flow direction from the landfill Infiltration
recharge and leakance from the stream into the landfill provides the
necessary elevation to cause outflow in this direction
Contamination from the landfill to the surrounding streams is
evident (Table 4) During the period 15 August 1981 to 27 Octooer
1981 there was no flow in the stream that Borders the northern and
eastern side of the landfill until a point just south of the E well
was reached High specific conductance levels in the EC and NE
wells were recorded (1000 jjmnos) At a point directly east of well
EC a pool of water existed that was relatively uncontaminated which
is designated as the East Stream] location (Fig 10) At a point
just south of that (East Stream^ polluted water in the streambed
was flowing at a low rate This was measured at the SE weir
location and which had a high conductance also Flowrates varied
between 6 and 23 gpm and specific conductances were over 350
pmhos This low water table condition flowrate is the baseflow from
the eastern side of the landfill and indicates a southeasterly flow
direction from it
Streamflow commenced in tne northern part of the stream 21
October 1931 and the north dam oegan to f i l l Stream specific
65
conductances were low indicating a clean water source Tnis
continued until 17 November 1981 when the dam overflowed ana flow
throughout the east stream began A weir was placed at the Rose
Hill Road NW location and was compared to flowrates at the SE
location Flowrates decreased and specific conductances increased
between these two locations
To further investigate the condition of a lower flowrate
downstream than upstream an intermediate weir was placed at the E
weir location (Fig 9) This snowed tnat the stream from the M
weir to the E weir was losing water to the aauifer (influent
condition) and gaining water at the SE weir (effluent condition)
The condition of a net loss of water between the NW and SE weirs
remained until 19 December 1981 when a snowmelt rain condition
caused increased surface runoff and a net increase in flow at the SE
location Upon analyzing the March and April 1982 streamflow
conditions the expected case of a net ground-water pickup from the
E to SE weir continued The explanation for tne initial net loss of
ground-water is the fact that the leakance from the upstream section
was being discharged into aauifer storage to raise the ground-water
table to an eduilibrium level Upon reaching a high recharge
equilibrium steady state condition any additional input will
eventually be transmitted as baseflow out of the landfill and a
downstream net pickup will occur A hign water table condition
prevailed during the January through May period maintaining this
condition In April the north dam broke through reducing the head
in that area by 4-6 feet The 9 April 1982 monitoring revealed that
66
an influent condition remained between the NW and E weirs but at a
reduced rate The 21 April lower stream flow condition shows a
small pickup of water between the NW and E weirs indicating the nigh
water table and low stream flow conaitions combined with the absence
of the dam had changed the conditions to an effluent condition
This was evident in the May monitoring period
Evidence of contamination on both the western and eastern sides
of the landfill supports the existence of a ground-water divide in
the landfill The west stream which drains the excavated area to
the west of Rose Hill Road shows contamination pickup between its
northern section and the SW weir The W well and ooservation hole
indicate high contamination levels which reinforces the concept of a
contaminant outflow to tne west excavation stream
As shown previously flow towara the eastern side of the
landfill is evident from the nign specific conductances and specific
conductances increases in the stream This is especially evident
during low flow conditions when the stream starts at a point to the
east of the landfill and flows with high specific conductance levels
From the literature a relationship between specific conductance
and dissolved solids exists the dissolved solids (mg1) are
approximately equal to the specific conductance times a factor
ranging between 55 and 09 (39) in this case it is taken as
065 (41) The dissolved solids increase coupled with the stream
flow increases provides a basis of calculating the dissolved solids
outflow to tne stream This calculation method was used in a
previous study (26)
67
The relationship
=Cinout Coutflow Qoutflow - Cupstream Qupstream Qinput
where the numerator is the streamflow pickup and the C- and
Q-jnput is the concentration and flow input from the ground-water
This can be used to estimate dilution level outflows from the
landfill Initially this is used for the ambient ground-water
pickup between the E weir and the SE weir This entire flow doesnt
come from tne lanafill but much of it is conaucted in the high
transmissivity area between the lanafill and stream from upstream
leaxage ana surficial recharge Tnis is evident when this section
of the flow pattern is analyzed on Fig 22 Therefore the landfill
outflow is mixed with tne ambient groundwater flow which dilutes the
landfill leachate before it enters the stream To illustrate-this
concept a calculation using the 9 December 1981 monitoring is used
At this time a flow of 672 gpm occurred at the SE weir with a
specific conductance increase of 7 ymhos between the E and SE
weirs The dissolved solids increase would be approximately 795
Today in tne stream
Where
Co = 90 jumho at SE weir
Qo = 672 gpm at SE weir
Cus = 83 jumho at E weir
Qus = 606 gpm at E weir
Qinput = 66 gpm gain
Cinput = 154 jumho
68
The 154 jumho value represents the contaminant level in the
ground-water adjacent to the landfill
This relationship is applied to approximate the concentration
level dilution in the ambient ground-water between the landfill and
stream The aforementioned relationsnip is in turn applied to the
landfill outflow into the ambient ground-water flow adjacent to the
landfill The ground-water receives landfill leachate dilutes it
and then transmits it to the stream The previously calculated
value of 129 gpm was used as the outflow from the landfill
Co 154 jumho flows into stream
Qo = 67 gpm flow into stream
Cus = 83 jumho background level
Qus = 67 gpm - 129 gpm = 541 gpm
Qinput = 129 gpm from landfill
Cinput = 451 jumhos
Approximately tne same contaminant levels from the landfill (tbl
umho) are arrived at as existed in the summer streamflow conditions
when the upgradient ground-water flow adjacent to the landfill was
at a minimum
In addition to using specific conductance to define
contamination zones electrical resistivity can be used to indicate
contaminated areas The measured earth resistivity is inversely
proportional to the conductivity of ground-water Water containing
contaminants with high ionic concentrations are more electrically
conductive and will have lower resistivity values than surrounding
natural ground water Therefore resistivity methods can be used to
69
delineate plumes of contaminated ground-water that have hign
specific conductances This has been demonstrated by several
investigations (11122328374045)
In this study a Schlumberger vertical electrical sounding R-l
was made in an area of known contamination at the W well (Fig 12)
Given the geologic constraints provided by the well boring log a 4
layer computer model was used to match field survey values A
Schlumberger sounding R-2 in an uncontaminated area north of the
landfill in the same geologic setting was used to provide a
comparison background sounding (Fig 12) A seismic survey N-4 was
made to obtain water table depth and depth to bedrock as input
parameters to a four layer resistivity model (Fig 8) Tne results
of the electrical soundings have been tabulated in Table 6 and
plotted in Fig 27 and 28 respectively
The ascending portion of the field Schlumberger curves were
initially matched using a two-layer ascending type master curve to
provide an approximate depth and apparent resistivity of the
overburdened topsoil layer (8) Tne second unsaturated layers
apparent resistivity was determined by using the graphical
interpretation of total transverse resistance The total transverse
resistance is approximately eoual to the peak value of the curve
times the corresponding Ab2 distance it occurred at This in turn
is eaual to the sum of the first two layers apparent resistivity
times their corresponding layer depths
70
bullH
OJ bull bullH 4J CO CM
c ce G bullrH
j-gt ca c c a 3 ltu O L
co CO 0
bullo Q bull laquos c n 3 -U OrH f~ 3 bO ltn y CO O cc CO ^mdashN
QQ bull
bO bOJJ C C Ci_i
O l T i O O O O O O O O O O O O O O O O bullH bullH mdash^ bullo 0 C c3 f| 3 O raquo O CO CQ
CO
rH
CO O
L 4J
^ltU
i- 1 ^n ^b O 4-) bull2 CM bullH C OJ 1 -U bullH CO C L O a ^-^ 0) a
rH c a L CD ltu (1) 3 tlt bO cO I
3 a 0) a Q 4J laquoa e CO 3 (H bO c C O bullH
CO TJ C 3 bull
bull O bO -i-3
0 CO C O3- O G O O O O O O O O O O O O O O O O O O ft rt1 -raquo - t l S^ ft tfigt f I mdash^ K_ l_ raquo mdash I gt fgt I l 1
(1) 0 rH CO CJ JD o^^ CO CO CQH lts
71
Legend
A actual field measurement
-e- interpretat ion
10000 bull
6000 bull 5000
4000-
3000shy
pound2000| ltD
_ r 1000
09
5 600 pound 500 - 400
I 300 a a lt 200
100 10
Fig 27
20 30 4050 100
Distance AB2
Schlumberger Sounding
200
feet
R-1
400 600
72
loooot
6000 5000 4000
3000+
laquo2000 e
r 1000
raquo 600 pound 600 ~ 400
$ 300 a a lt 200
100
Legend
A actual field measurement
-Qmdashinterpretation
10 20 30 40 50 100 200 400 600 Distance AB2 feet
Fig 28 Schlumberger Sounding R-2
73
Formula T = f
Background Sounding (9000)(15) = (3110j (1 7) + gt2(8)
= 16214 n- ft
W Wel l Sounding (b200)(60) = (500) (2) + pound2(28)
= 13250 SL- ft
To determine a resistivityp3 value for the third layer a
graphical interpretation for the longitudinal conductance S was
used(48) This is eaual to the sum of each individual layers depth
divided by their apparent resistivity
Formula S = -r1 +~r-raquobull-ra
Background Sounding 0017 = yyg + ~^
= IbOU - ft
W Well Sounding 0285 raquo -ggg 7^3 J~
= 179 v-ft
These values were input to a program which calculates a
schlumberger sounding curve (47) The theoretical sounding curves
approximately match the field curve as viewed on fig 27 and fig
28 To provide a check on the apparent resistivity of the saturated
layer at the W well the following relationship was applied 1OOOO
= spec-jfic conductance (umhos)
74
At the W well the specific conductance was measured to be 3 00
jmhos at approximately 10degC
Assuming a formation factor of 45 for the glacial outwash (23)
material Archies law is applied to estimate an apparent resistivity
of the third layer (7)
fgt FF x p
A= 45 x 103-n-ft
A= 4G3 JL-ft
This is a reasonable approximation to tne 3i= 179^-ft calculated
analytically from the sounding curve interpretation
75
Remedial Measures
With the analysis of f low patterns and contamination zones
recommendations to minimize the environmental impact of the leachate
can be reviewed The basic technique is to minimize all sources of
water reaching the refuse so that leacnate production is minimized
The oiversion of precipitation by a relatively impermeable cover and
proper channeling of runoff would minimize percolation into landfill
material Caps and seals can be constructed of clays fly ash
soils soil-cement lime stabilized soil memorane liners
bituminous concrete and asphalttar materials (15) Proper
contouring and grading will help minimize infiltration If a soil
cover is used a vegetative cover can be planted which will utilize
some of the infiltrating flow through evapotranspiration losses
during the growing season By minimizing the length of slopes and
providing proper drainage channels tne surface runoff can be
conveyed to a downgradient area outside the recharge zone
Therefore this surface water will not increase leachate production
from the landfill Also by increasing the slope of the cover over
the landfill itself a higher percentage of runoff and lower
infiltration will occur
To minimize upgradient ground-water influx to the landfill an
impermeable subsurface barrier or intercepting trench could be
used Barriers can be made of bentonite slurry-trench cutoff walls
grout curtains or sheet piling cutoff wal ls extending to the bedrocic
or an impervious layer to effectively prevent water passage or
create a head loss that wil l lower the water table In addition an
76
intercepting trench which has a perforated drain at tne lowest part
of the water seepage zone could be used to intercept and divert the
entire flow
These possibilities have been evaluated with the help of the
model to determine workable solutions for this landfill The
primary concern is to eliminate leachate flows to domestic wells
Initially a simulation was run that eliminated recharge over tne
landfill area (Fig 29) This had a considerable effect on the
ground-water flow patterns of the landfill area The mounding that
had previously occurred under normal recharge conditions was
eliminated and a general drop in the water taole within the landfill
of 2-3 ft occurred The effect of eliminating recnarge over the
landfill when the upper stream is running would cause greater
infiltration from the stream as evidenced by only a 2 ft head loss
in the landfills flow conditions This is evident when comparing
Fig 29 with Fig 24 Tnis indicates that this measure would only
marginally reduce the resultant leachate flow from the landfill
material that lies below the water table In another situation
where there is not such a strong potential for upgradient flow this
measure has proven quite effective (6) In this case the landfill
cover consisted of four layers an intermediate sand and gravel
cover immediately above tne regraded waste materials a 4 inch sana
bed designed to protect the overlying membrane a ilO mil flexible
PVC membrane and an 18 inch final cover of sand and gravel
77
Legend
landfill limit -raquo- -^ -raquobull excava t ion x-^x- s t ream
400 copy WNWNEECSESC monitoring well locations
= -= unimproved road fee t
Fig 29 No Recharge over Landfill
78
Controls such as 10-30 mil polyvinyl chloride covers favor the
development of an anaerobic environment which increases waste
decomposition time and would necessitate installation of gas vents
at several locations on the landfill cover Tne integrity of tne
synthetic cap may be further threatened by subsidence which create
differential stresses on liners Settlement would create areas for
ponding and depression storage and eventually necessitate regrading
the landfill surface The landfills south-central area has oeen
filled within the last year and will prooably need to be regraded
due to settlement within the next few years
Another possibility for a liner would be a soil-bentonite
cover A layered cover consisting of natural materials with low
permeabilities such as bentonite clay followed by a layer of highly
permeable material such as sand and finally a layer of topsoil can
be used Due to potential drying out and cracking of the clay liner
a synthetic liner is the preferred method
The most immediate technique is to grade contour and vegetate
the landfill cover which has been done at this site Althougn an
impermeable cover would probaoly reduce the amount of leachate
produced it would not eliminate the upgradient flow and provide
guaranteed protection of wells in the vicinity of the landfills
northwestern section
A slurry trench along the northwestern perimeter of the landfill
would effectively cutoff upgradient infiltration and divert recharge
infiltration in a southeasterly direction thus removing possible
leachate outflows from the radius of influence of the neighooring
79
wells This has been simulated using the computer moael ana flow
patterns as shown in Fig 30 Contour lines are distorted in the
vicinity of the slurry trench due to the 200 ft nodal spacing
Transmissivity values of 1 ftday were input at the slurry
locations to simulate an impermeable barrier Tne surface recharge
at those nodes does not infiltrate the relatively impermeable grid
nodes at the slurry locations and flows to the edge of the noae
thus creating a dramatic head loss within a short spacing To
effectively simulate this a variable grid spacing should be used
with reduced node grid spacing at trench locations to eliminate
distortion The computer simulation shows that the slurry trench
could direct flow in the landfill area in a southeasterly direction
and away from endangered wells In addition it would reduce
upgradient infiltration from the stream into the landfill This
measure would prevent leachate from spreading beyond this carrier to
possibly contaminate neighboring wells
The combination of both the slurry wall and impermeable cover
would be ideal measures to minimize generation of leachate and to
stop its spread to neighboring wells The slurry wall without
recharge over it or the landfill is simulated in Fig 31 This
indicates a lower water table tnan eliminating the recharge to the
landfill The slurry wall has blocked upgradient ground-water flow
at its location to the landfill
80
Legend
landfill limit -laquo- j -laquobull excava t ion ^^- stream
copy WNWNEECSESC monitoring well locations
= = = unimproved road ssi slurry wall
f e e t
Fig 30 Slurry Wall
81
Legend
landfill limit j- j- J- excavat ion x-v^gt- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road s==s slurry wall
400
feet
Fig 31 Slurry Wall without Recharge Over It or Landfill
82
An intercepting drainage trench is considered next If a trench
was excavated to a 30 ft depth in the outwash material extensive
shoring would be required In addition difficulties would arise
when the trench was excavated below the waterline Tne trench would
be sloped to provide drainage and backfilled with a highly pervious
material to intercept and divert leacnate locally a conouit which
is perforated on the top to allow infiltration and unperforated on
its lower perimeter to permit continuous drainage to the collection
treatment center would be installed on the bottom of the graded
trench The difficulties involved in excavating below the water
table ano shoring the sidewalls to permit implacement of a drainage
conduit at a 30 foot depth make this option increasingly infeasible
83
Conclusions and Recommendations
The location of the South Kingstown landfill in permeable sand
and gravel glacial outwash material (107 ftday) combined with the
high hydraulic gradient across the landfill area (20 ft1600 ft)
creates a high potential for ground-water contamination to occur
This is intensified because refuse nas been placed below the water
table The low hydraulic conductivity of the compacted refuse (1
ftday) and the excavated area to the west of Rose Hill Road have
both contributed to modifying the original southeasterly flow
pattern These modifications have created a ground-water divide in
the landfill at approximately the western third section Tnis
results in approximately 13 of the leachate flow from the landfill
or 63 gpm flowing in a southwesterly direction and 23 or 129
gpm flows in a southeasterly direction Infiltration from
precipitation recnarge over the landfill (up to 9Upound) and from tne
upgradient stream during low water-table periods provides tne
necessary influx into the landfill Evidence of contamination is
clearly seen on both the east and west sides of the landfill which
reinforces the previously stated flow patterns
Of the several remedial measures reviewed the contouring and
grading of the landfill topcover and drainage swale provides the
most immediate protection The topcover has been graded mulched
and seeded to provide a low runoff slope generally to the east
The drainage swale on the left side of the landfill has improperly
graded sections which should be corrected Its northern section
could be drained into the northern sections swale and the southern
84
section drained to the southeastern section of the landfill Tne
point of the drainage swale which divides the northern drainage
swale from the southern one should be determined by a field survey
Cost is a major contributing factor when determining which
remedial measure is to be applied to the given situation For the
purpose of this report cost estimates are not presented but rather
the effectiveness and feasibility of the remedial measures are tne
primary considerations As was reviewed and simulated in the
computer models the slurry trench and impermeable cover over the
landfill are two viable options that would effectively provide
protection to the domestic supply wells in tne vicinity The
impermeable cover would eliminate precipitation recharge into tne
landfill yet drop the water table only a few feet due to upgradient
infiltration from the stream This would decrease the hydraulic
gradient thus diminishing the potential for a contaminant outflow to
surrounding wells The supply well of primary concern is one to the
west of Rose Hi l l Road marked well D on Fig 2 If contamination
occurs in this well the most effective measure would be to block
off leachate flow in this direction by installing a bentonite slurry
trench at the location indicated previously This would effectively
prevent leachate flow in the westerly direction and diverts it to a
more southeasterly direction In addition the slurry trench
precludes infiltration flow into the landfill from the upgradient
stream
85
Tnis report has effectively reviewed tne original ana existing
flow conditions and contaminant levels in the vicinity of the Rose
Hill landfill The purpose was to provide an understanding of
ground-water contamination patterns and study possiole remedial
measures
86lt
Appendix A
Precipitation Records
Monthly normal precipitation 1941 -197O
i$l Total monthly precipitation
KINGSTON RI
14
ia
^JO T I bullbullL
pound 111 laquobull
4
a
n
-
^
-
-
KS1JAN
^Ii R3 HB MAR
1
1 APR MAY
1
1 JUN
1981
JUL
-bullraquolaquo H
AUO SEP
K3~~f$s bull
_imdash
i1S 1
OCf NOV OtC
171 1 iI1
JAN HB MAR APR MAY
198
Fig 32 Precipitation Record
- - - -
IM 1 MtvJrflgtlgt c ortli-A t lUN I r nraquo rl - -
gt|MO CLIMATOLOQICAL OUSERV ATIONshyr-r bull JK gt raquo - 1
i5fWA I VAPOR Al IOH -bull AIM If MPCRATUM bullF 0 riccipn AT ION UNO IlMf
bull 14 H 14 H mdash Vshy ADDITIONAL DATA IfUAlUS OATt 1 bull raquof bull bull 1 ta
14 Hw rlaquo4 w bullbull bull 1 114 1mdash4 (llrl 1 1 1fl Hll
0 kmdash
Mraquo M4 raquo i T i 4 bullraquo-laquobull i i
Lgt f 1 21 S 1 Hbull - - bullbull -
ltJL 1 2 01 - - _ _ 1
mdash
-
1 12 _ Q I
mdash shy
mdash 4 (C ( - - fVi 1 - 0
1 (1
^ 1
Vvraquolaquo IJ1^ raquo CP O 3L 1 Z - i bull j-t-J
1 J
LH Vb T n 0
1 gt fl oo O ~l 2 L - bull 1 P )laquo jn iP IP - OOI L5L mdash shy
-t 84 ^(^^ ^fi P i flja 0 JO II 10 tl tcgt 7 J IV wllaquo
h l2L bull 0 lt -_ shy
-id VJ lt 3C 2 ft OOL -mdash
U 71 C1 Sr 2 13 2 nl JLJraquopound HP r M ltf1- (
IMe 2 ii O It
n jlt dl 1 1 bull o o-il ST i 1 i 25 2-x-1
-
ri
i tlL O mdash gtbull bullgtlt 1ft -o- is Oil So iJK 2-io otv u 31 fil loi 2 il Oll it Of wr is i1raquo -iZ 1 deg|0 01
M IT So - mdash
- 13 1 CT mdash i - mdash 21
shy
Tl Ci av ZUll IMT 0 IM Pe v _ 1) T) S) ii3( dlt Ii 2 lt^2 II li- S1 riivi To 7HX lt3lO 14 ^2- iTi I li 011 -- - -i -^IS no 5^ or i | T Jift laquoV OoH bullla It Va iCO mdash L OIL 11 bullvf poundgtpound lS_ flv oh P-lfe 1 poif _ shy11 IB kl (4 itlaquoT lamp llt0 oot^
mdash -n
It T1 |ir( L1 HI 2 0 oil
U 1M ft go C ICf^ -^2 Z laquo-|o
11 it 5 bulln - TO o abull Li u-i IT1 -- Iw O ltM (I bullbull bdquo-I(K 1mdash -tilltLlA ttfe
i Dgt ac -- U 44 4 11 1 1- ytd i i_i J-K 0 i if -i i i V t Wl raquoOHM 1-1 US D C P A R T M f N T OF COMMfRCE t 4 1 IUII 1 1 ^~) mdash
llaquo- Hi NC bull bullh bull bullJL^V HBl CO 00
11
)jLsVyr^gturv
^ | TKu
|-_t_ bull(
IIMgt I I Mt|UU III- II 11
PNECIPITATIOH
I 1 1 IMX
IMO
bull llfclaquo I UCIUKI) Ur C V A r U M A AHO CLIMATOUOCICAL OBitH
E V A F O R A T I C r i Jttffl laquo amp hMIlaquoJllaquoJIIlaquoBgt
DATE AOOITIOMAL DAIAKMAKk M
bullraquobullmdashlaquo
tp 01 (1 Of Ll OOI ooo
0^1 o-i 10 tl |00 102
OC (1 13 Ofl
it i rc DS os an
(1 SV o
Ul 010
(ISl 101 I on
130
II 5= Otl
ss lt 001 (IK Ml
jt il HIT
7 it
ow Wo 17 Top 2-01 OIO
(0 oov zi oot
u CO ^A 0 to Zoi CLflS
bull50 01 ljtj
nshy 5H LO OIt
50121 IVO QJO
14 Co Ho LO Hl ^pound Jl 1
ltM ool fllc
H Tl 01 II
11 11 Q1
iH OIO
HO 2 llaquol 11 II
lifc
IV-IIM ul OIPAITHINT or COHMIICC NOAA
NAtlOHAL gtIATnlaquoll raquotraquoVlClaquo CD
r~
All TCUMMATUNI ^V UII rgt ITmi 1 Cwphu Obic i gtn t ngir-H 30
rilCiriTATIOH
JJ T I rTJ-rimdashr-iramj|MP CLmATOLOQ
laquolaquo jftilCiii bullIHO
Oi1l ADOITIOHAL DAIAlllu
Ilf4ft
Sii1
(1 2 IO OO
Hl ii SO
us OIM
Q^L
a A3 Hi SZ Sf^ bull 12J2
HI Z-SF OOl 1C t HM IA H ICP fiJA
OOl 10 (310 sn 310
if HI (0 ^01
bullit SO 28H poundJ1 11 006
14 35 TX oon II (bull2 it zr II c-S
rr Zll lo 31 OP an 31 a 31 oor
CSW O-ll Si CC Of 011
Oll _ I |ft
00
u i oerraquolaquoTMiMr of c NOAA
NATIONAL K C A T N C M SCMVlCC
TC^S lk)oiVroTJA
TETT I 7X
1raquolaquolaquo 4 bdquo ir lt er ni I^OV ltqgl j--^ TQ
MICiriTAllOH ITIND
D|mdash
b5NO ctiUATOtoiCAL oeit^
OATI AOOITIOMAL OATAVlHAtt
0-tt
Mlaquoh bullbullbull- rshy laquo
I- ltltriu HI I 4 bulllaquobullbull1
Zii
30 Dfellt otvt
at HA
OOI
62
iJ_S2 HI if
bull- 20 SI 2i So
So
VVfr
OSfc
I (
Jtlt
3aoi
r j -bull ie MA
Irill iiol
in^ 14
Mo
Zll
214
21 1P
00-i
bulliron
17
bullr
11 i ir- I J Ktf^c
US D E P A R T M E N T OF COuMEDCC I | C gt A A
K AIlaquo Ttupf lATuit r
|SlVi AlJ PIICIPITATION
oJud (El
VIM i Uraquo
MIND E
EVAPORATIOH flnrft bull A ftufiifccdll
KECORO OF eVAPllHAtlil bull I CLIHATOLOOCAL OBSERVA ^Hij
14 MM A_M AOOIIIONAL DATA11 MAIM
Mr bullH Oo|
M Si lift
bull221 IHI
ZS Ji 40 IZV
icr KS I
HZ 111
bullT 21
loA UK JA IP
v^ ft
1M 2Sshy IT Tl
71 V |
i I 31 1deg a
uty^ U bull3
ons 1 CiO TxX
HHO (10
3H 19 12 10 IP
raquo3H raquo | 5t io
OP OIT
14
vO UI Of PANTMINI Or COMMCRCf MM O A A
F ngt TIHH
iiicffwiffc 4 rJ (TIM bull Cempltit Obitittiio
AIlaquo TIMHIATUM PHICinTATION I V A f OK ATlPrl
OATI ADDITIONAL DATA KMAlIt
U4laquo4 +
03H Ji
10
rc a 1 16 oi ii
tiiy 10
OI
II i23 or o 13 -y~ou HO
II 3V III i 3 t
V laquop oot
OM1 SS ne
T an -i IP
Olt zr LTV
3T 001
a -11 2T
10 an 31
-1 raquo 131 UP 3H lf 14 Lpoundshy
it 14 30
IS
Ui O I P A K T M f H T OP COWlf ICfM O A A
NATJONAI V C A T M C n f t K M V l C K
bullbullbullbullbullshy -2 o AIlaquo TIMMRATUM f fKICIPITATIOH
OATI poundt- MMINMAL DATAk
ZP 51 lo icr
011 111
OoT IHf
Ut 003 am
3o 13 ao
4A X 05shy
H4 i IjJyiV131 ooc js
IH oi 01 tL 18 13 a
No 11-7
rivgtp OO| M Hi 03 01
It 12
bull I 41 bull7119 14 ^^ raquo 31 15 lampk n M ho i
Jo -j-
-J
I
Ml H^ I _
amp2ampUi^= LS 0 S 0-f bullTTT
-Vmdash gt U_ bull 1 rOHM I- 11 OI OCPARTMlNT OF COMM(NCC
HO NATIONAL W f A T M f H ftfraquoVlCI
98
Appendix B
Boring Logs
99
X iHECT 1 ff 2
OAT American Drilling amp Bor ini I Co Inc
wo WATH smn EAST PR ov IDENC E ft 1 Town of South Kingstown South K ngstown R I MOLENO X-J
TC 100 RCSS bull ujrMonitorinq Well Installation | South Kinqjtown R I UNC a STA Pf KXICCTHJ LOC ATK3N
bull cfrserrr TO above S MPLES S FNTTO _ _ |laquolaquor A-109 SURF ELEV RE PORTSEr
GROUND WATER O6SE RVATC MS 1 CDREraquolaquo m-T nn75 laquo A 256 - 20 mdash Hew y
Instolled 32ofT-l2 PV C - JO- COMPUTE 111275 K toia 3- I-WI 1-38 TOTAL MRS bdquo10 screen BORING FCACUAM J K lanq MAI rraquo HomnwWI 300 140 IampPCCrc Mamlaquor Fall 24 30 lampaaiona SOLS ENGR
LOCATION OF BORING H ONITOKING WELL
Coung Samplt Tjp Blow per 6 Manure SOU IDENTIFICATION Strata SAMPLE ^^^yV Bloot
foot
Otptni
From- To
el
l
on Sampler
0-6 1 -6-13 12-18
Dentity or
Conmt j
Chang Remark include colo^ graaation Type of tod lie Rao-coMr type condition nordshynetiDntotf time leamt and tie No Pen Rtlt
2 No top sample 5 12
1 loamy fine sand
bull)^ 40 30 36
5- 616 0 23 20 16
noist iense
Brown fine to coarse SAND some fine to coarse gravel Trace silt
^
1 18 18
36 8-0shy57 40 30 V 35
|0-||-6 D 14 24 20 Srown medium to coarse SAND Some fine gravel cobbles
7 IRshy 16
27 75 37 3
IS- I- D 5 14 16 3bull
ISshy 15
42 50 I9--0shy50 65 20-2ll-6 D 9 23 26 bull Jrown fine to coarse SAND Tbullwshy 1Z 75 90
22-0 Trace silt trace fine gravel
124 120 74 60 52 41
7S-ltlaquoil-A DX 71 16 13 wet very dense
Gray-brown fine to coarse SANC Some fine to coarse gravel little silt
H IR u
40 30--0
3C-30-IO
3l4-334
334-3314
38 4-434
D
c
C
C
7 IflO
94 6
we tr j
y se
ft irox
30MOshy
31 -4shy
Gray-brown fine to coarse SAND Trace silt
Gray-brown fine SAND some lilt trace fine gravel
Too of Rock 31 -4shy
Gray-pink GRANITE
6 7
amp
CJ
IltJ A
60
601
IQ mdash
2(
4
5 i Hard
ft 5ome seams bull
GROUND SURFACE TO J 4 U3CD_ ^JVrf bullbull( tutu t to 4o 4 SampM Type Proportion UMd MOB Wtx 3 OfaM on 2OD Sampler SUMMARY-
OOry CCartd WltWen4 Hoc OlolO Canmonieraquoi Don any CoKeem CarMWncy Earm Barrlaquoj 11 14
UPgtUnOigtturod Piuon trite (Oto20dego 0-Kgt Loei it 0-4 Sait 3O+Hofd Rock Corng 14 Kgt-30 laquo4 0 rte 4-8 MSHM Samplet TPTtitPit Ai Auger Vvanefett tarn 2Olo39 3O-M Owlt n laquo-lS Strlf rinit nn v 1
UTiUndlshffbed ThrMOll and bull 33to9O 5O Very 0laquo nraquoe 19-30 V-3trraquof - | OLE NO X-l
TOVH rim - iA it raquotoraquo
100
SHEET 2 o_L
WO WATEt STUET [AST ft OVIDENC pound a i American Drilling amp Bor ing Co Inc
MCLl WQ X- 1 Tt AOORCSS i
LIME A STA KXICCTMJ tuf same as 1 | tame as i LOCATION
W PORTSEf mo OB nj urt eflaquo T
illtPLES S
P
CVTTO nlaquo mun orv
^s f^ Tin i GRCVMO WATER OBSERVATONS CASING SAMPLER CORE BAR
START Typi COMPUTE tome at 1 same aiH
TOTAL MRS BORIMG FOR CMAN n bull IT INSPECTOR SOILS EMM
LOCATION OF BORING u HfVJTneTfi UFI _
8
Counf Blo-t
foot
Dtpllo
From To
0( on SampMr
0-6 f 6-IZ
Moittir
Oonuty or
Contilt
Strata Ctnngc
SOIL OCNTiriCATION Rtmorkt ineHifl cotot grqdotion Typlaquo of Mil etc Roo-axtrPlaquo condition Mrdshynlaquot Drog tun ttomt end tic
SAMPLE
No Ptfl RfK
434-4o4 c
approx 7 minj
per toot 454
Gray pink GRANITE Hard Fairly solid core
lt_4 24
Bottom of Boring 45 -4
-
~
bull 1
GROUND Sorrow Tye
SURHCZ 10
bull OiOry CgtCord WWothod UPUnditiurMd Piston TPlaquoTtraquotPtt AtAuotr VVor
UTltUndinrvd TTMMO bull bulltat
iivnPilaquo(onioni Uraquot4
me OioiOItttt laquoraquo20
wmt Z0ie33
and 361090
c M
C1 5 Si
-SOshy
ASING
IOtgtWtigt bullnlot Dn 10 Loci M Mod 04 SO Dm 1shy Viry 0laquo
s _
TMEN 0 hMl on 200 SoiTBUr laquoity ConcMMt Conorawncy gtbull 0-4 Sort 30shym 4-B MStlfl M BH9 Strtf bull ts-so v-swt bull
t-HOrt Ear Bern RoetCorrt
i ^^^^^ bull
-[MOLE no x-i
101
raquoMEC rAmerican Drilling amp Bor in g Co Inc 1 ofj_ DATE wo WATlaquo smn UST Plaquo IOIDCNC j laquo i
Town of South Kingstown South Kingstown 8 MOLE MO Jlt Z TC rx MCS3
rtprr uAurMonitorina Well Initollation | South KinqitowrxRI UNC A STA P KATIOM ME POCT ^rwT TO above I OFFSZT
uD^r laquorlaquorTTO 6 -109 suw tLEv Sgt louffJOCNO
0 tj Tlmlaquo WOUND WATER 06SCRVATC US gtW Rsdl SING SAM^EH CORE BAH
26 ^_ 12 $TAlaquoT UL 2Z2i Ji r TTP NW ltA sr IJZC Z5 CCOMPLETE
SitLO 3 I-3B- 1-38 TOTAL MAS 41 BOAINO FOACMAN JK1 ana nf ni n MonwwWl 300^ 140 BIT bullK^CT
gttonvrar Foil J^laquo 30mdash Diamond SOOJIEMGM
IE HFII
iCaunq SampM Trplaquo BMMtpw6 UOIIIK- SOIL DCMTIFKATION Siraia SAUPLE Blow DlaquoPIAraquo of on SompMr HtmorU mcJuo cotes gradation Type of Dwuily
pw or CXang writK Roel-eolorlyp condition tvort-From- To Vfoot 0-6 f 6-2 12-18 Coniitt egt rwtiOnAngtimt wamaondtte No Praquon Rtlt
2 Brown fine SAND little silt 2 2-0shy5 15 18 moist Browi fin to coarse SAND 18 5- 6-6 0 14 25 27 vlaquo Troc fin aravel | 25 wy Ifl 11
dlt tns 35 40 38 moist n in-il-i Lgt U 15 18 ie is li1 Irl IS 31 I2-0
~~43 1
A) Jrown coars to medium SAI MD 48 moist Little fine to coarse gravel
|5-IA-Xlaquo 14 47 41 fn D laquo y Little silt rrqa coarse sane 3 18 I1
68 In IS 44 32 34
n ^n-^i-A- w 2o 19 29 wet 4 la -59 lens ltfO no
25-0 2amp bulllaquo- 77 c BOULDER r[ 4 i
27-0 5X ~W 24 24 bullWar- 5 Ifl irown tine to coarse SAND some
dens 29-0- Fine-coars gravel trace silt
30-3I oxx 30 32 30 moist irown -gray fine SANDiom e 6 l rr Vlaquoy 31 -0 silt trace fine oroveTILL
Bottom of Boring 31 -ampbull shyBent casing -pulled out and moved over 4 - washed amp tJrovlaquo casing to 30 -Installed 3C gtof 1-12- PVC - 10 screen
WOUND SUraquoraquofCE TO 3pound 1 yijfD MW t ASIMC TMCJ laquo olaquorod -bor of borina
SomoU T]Fplaquo ProigtuliOraquoH UMd MIOtgtWLx3Orolt lon2OASanlaquoMr SUUMARY-D=Dry CCorad Wlaquoworaquonraquod bullact OiaiO CanM gnMM Daonty CIMIH Caamraquoci EffW 8or^ 2pt
UPiUnairurMd Pition Itnt laquoM2O O- O UKraquolaquo 0-4 Soft 3O-hHard Roelaquo Corrig o- JO M0mlaquo 4-8 MSNff SOTipM 1 p^ 3O-9O OwgtM bull-IS Slid
TPlaquoTraquojraquoPit AAugtr ViVon mini tamt 20to39 UTtundiifir6d TrwMOtf and JSloSO 50-raquobull Vary 0nlaquo [HOLE NO x-2 B-3O V-3Mf lev rim - IAIT raquosectlaquoraquo
102
300 iu 24
1 UMnii ffi 140 laquo 30
CA1INC tf
gt taWCTf
bull 0gtlaquo i R Cook Jr_ R Millineton1 Wttn
I~
1 VAMtl CtMG
1 W HO-t MO
1 Oraquo 1 laquo0~ twt
L 1 laquo-raquo VfcM^lf [wlaquoraquoCI ^ ^ K3Ot III laquo
0-LS D
5-65 D
LlQ 10-115 D
15-16 Tgt
Lraquo 70-51 n
25-26 D
F
I O-O Ci
A Allstate Drill ins Co vi o i
PROVIDING R 1bull raquoraquo uvraquonn~ N M O M I T O P I N G HE1 _^lt -^ PI-Traquo UJU
CUM Town of South Kineraquotown raquoraquo 1 1TA maoer Propolaquolaquod Sit for Slude Disposal nltn
laquo V-449 iampAAtut i a 138 ort STI bull r 42777 CtOuMO IKVtllON
Cill bdquo 258 DA II MN ru 42777 rilaquolaquodO laquoraquoTti rum 1911
AU1TATI
MMUI1 raquolaquogtlaquolaquo laquoKiO itXHHKraquoriOi of sous MUAHI nMTKlion Ot CMlaquoMC|kOraquort tl CO~VH DXltgt raquomlaquo laquotf IMi COIOI C4l II I 1raquo gtlaquo^ Oraquo 1Ol rC t Xgttgt VtfKOe Craquo Mi 1 ft liMraquoK laquo0^tlaquot nfgt
1-2-1 10 TOP SOIL FINE LIGHT BROWN SAND traclaquo of ilt
16-31-17
22-24-21 100 FINE TO MEDIUM LIGHT GRAY SAND trace of fine gravlaquol and raquopoundLt
lfl-37-34 150 LIGHT BROWN FINE TO MEDIUM SAND little poundinlaquo gravel
21-17-15 200 MEDIUM TO COARSE SAND bullomc fine gravel
12-4-10
265
Observation well installed
NOTE No casing blows taktn
bullbull B-23 ow
^w^ 265 I raquo bull raquolaquo bull I W
11 laquot gtbullraquo Vlaquo 14 W gt_ c-shyji bull alaquo bull jraquo VI laquoHshyw bullbull m raquobullbull D-6 raquo Mshy
bull bull laquo Vshy
1
bull bull
I
103
MAMMII Allstate Drilling Co ulaquorr 1 or 1 FftOVIOCKZ H L traquolS mTArm^S MONITOR NR WEL
VNO wr3JJO__raquoraquou_24__ HCU MO P-74 n iu riBwi Town of Slt7H^ Xirpin
mdash^ laquo0J P 1 1 bull ^n^ciit^o TVlaquow^laquott1 bullraquoit wt 140 nu 30 olaquor fBu lkv Waste Disposal Arcai
MUTAH a V-449 R Cook Jr UMlaquoiigti D 1 38 0t| raquoIJ raquo 5277 rlaquo SUMO luvlaquorv-laquow
mdash 5277 fipe -raquoT pfpm 150
H MCIO IMNTlXAflON Of SOU t(kAIlaquoS rrn 0-laquoraquo
5 -SF 01 w in laquobull -raquo ^ lit
D 1-2-2 TOP SOIL V-1-oraquo
15 IPbull FINE TO MEDIUM LIGHT GRAY SAND AND GRAVEL
5-65 D 37-27-35 some silt
10-11 D 20-14-18
15-165 D i 17-14-14 155
BROWN COARSE TO MEDIUM SAND little fine to coarse gravel trace of silt
20-211 D 4-4-2
230 GRAY BROWN VERY FINE SAND
25-26J D 7-8-9 AND SILT 265 fvarvedl
Observation well installed
NOTE No casing blows taken
wta 10 n uuraquo c^imdashbull IgtM laquolaquobull- B-24 ow ~ 14 ltfc laquoraquobull vlaquo^ M laquobull r O 0 fmtt bull W-L 26 5
-0- CgtCmdashgt bull laquolaquobull mdash laquo 1 - raquoraquo 1 gt 1laquo bull 1 gtraquor to bull mdashbull bull bull bulllaquo I t l~laquo 1lt Uraquo mdashbull ) bull 1 gtbull ft 0~ H laquoy bullM ta bull -IN la laquobull OPUM bull($ IMI
mdash H raquo laquo-bull
104
Appendix C
Calibration of Specific Conductance Meters
105
Specific conductance measurements were made using a beckman RB
338 temperature compensating meter and a YSI rtooel 33 salinity
conductivity temperature meter The YSI meter is not
temperature correcting A formula to compensate for temperature
differences to standardize YSI measurements was used (21)
A long probe for the Beckman meter was used to measure conductivity
in the wells Differences in conductivity between the YSI ana
Beckman meters and the Beckman short and long probes exist These
were calibrated in the laboratory using 001 N and 01 N KC1
solutions Values presented are Beckman short probe values The
Beckman long probe values were reduced by 76 and tne YSI values
were multiplied by 11 to adjust to Beckman short probe values The
YSI meter was used in the latter phases of the study for the
stream contamination due to the greater accuracy of the dial readout
scale
Table 7 Specific Conductance Meter Calibration Table
Concentration (KCL) 0001N 001N
Specific Beckman short 145 143 143 1247 1245 12GO
Conductances Beckman long 190 191 188 1639 1650 1665
umhocm 9 25 C YSI 132 131 128 1131 1140 1150
average values Beckman shortBeckman long = 075
Beckman shortYSI = 11
106
Appendix D
Computer program Flow Chart
107
F1g 33 Computer Program Flow Chart-
1TpoundR MAP TCO
NEWPER
WEWSTP CZAX
HEWIT TRANS TCOF ROW COLUMN
Yes
Yes
108 The following is a description of the USGS two-dimensional computer
program Iterative Digital Model for Aquifer Evaluation updated
December 1972 by P C Trescott The program written in Fortran
consists of a MAIN program and six subprograms or subroutines which
themselves are organized into subprogram sections The subroutines and
their sections are listed below
MAIN Program
DATAIN (subroutine) COEF ITER (section) CLAY MAP TRANS NEWPER TCOF
ETRATE COMPUT STORAG
NEWSTP LEAKAG NEWIT1 NEWITO CHECK ROW CWRITE COLUMN STEADY PRNTA OUTPUT DRY BLOCK DATA
The program begins in the MAIN program which controls the sequence
of passage to the subroutines Sequential steps are described in the
program as shown in the flow chart of Fig 32 Emphasis is placed on the
steady state confined aquifer case as applied in this study First data
input is read in the DATAIN subroutine This data includes transmissivities
or permeabilities starting heads storage coefficients and grid spacings
Nodal transmissivity values are then computed for the water-table problem
in the TRANS section (COEF subroutine) This procedure is necessary here
because the subsequent routine for computing iteration parameters (ITER)
keys on nodal transmissivity values which would not have been input to
the water-table problem In the water-table option these would have been
109
computed from given bedrock and water-table elevations to obtain the
saturated thickness component of the transmissivity calculation In this
study water-table option was not used and the transmissivity values were
input directly The program then passes to the ITER section (DATAIN
subroutine) to compute the iteration parameters which expediate or even
cause convergence Next the MAP section (DATAIN subroutine) is utilized
to initialize data for an alphanumeric map if this was requested in the
input options Transmissivities are then computed for the confined
(artesian) aquifer case (water table not specified with input options)
in the TCOF section (COEF subroutine) These coefficients are harmonic
mean values of adjacent nodal transmissivities weighted by grid sizes
Time parameters and pumping data for a new pumping period are then read
in the NEWPER section (DATAIN subroutine) followed by entry into the
NEWSTP section (COMPUT subroutine) which calculates the size of the
time step Leakage coefficients (hydraulic conductivity of the confining
bed divided by confining bed thickness) are next computed in the CLAY
section (COEF subroutine) if leakage was specified in the input data
which was used in this study
A new iteration is then initiated in sections NEWITO (COMPUT
subroutine) NEWITO saves the current head values and compares them to
the updated head values for determining closure This is followed by
nodal transmissivity values being computed for the water table or water-
table artesian conversion problem Transmissivity coefficients are then
computed for the water-table problem in TCOF (COEF subroutine) Total
head values are then computed with the alternating direction implicit
procedure using the Thomas algorithim first along rows in the ROW section
110 and then along columns in the COLUMN section both in the COMPUT subroutine
Then if a solution is not obtained (because the error criteria for
closure is not satisfied) the MAIN program branches back to NEWIT1 subshy
sequent sections TRANS TCOF ROW and COLUMN repeatedly until a
solution at the particular time step is achieved NEWIT1 increments the
iteration counter and is immediately followed by NEWITO The program then
moves to the STEADY section of the COMPUT subroutine to check if the
closure criteria for steady state has been satisfied Output is then
printed in the OUTPUT section of COMPUT if steady state has been reached
or if the particular time step is designated for output
The program then branches back to NEWSTP (COMPUT subroutine) and
moves through the subsequent routines until the last time step in the
pumping period is reached Output is then promoted in the DRY section
of COMPUT if specified in input data If the last pumping period in
the problem has not been reached the program branches back to the
NEWPER section and moves again through subsequent sections otherwise
the program will terminate or start a new problem if one follows
This study was simulated as a steady state problem which can be
simulated by setting the storage coefficient of the aquifer and the
specific storage of the confining bed to zero and using one time step
of any length
111
Appendix E
Computer Data Sheets
RGSEA
10 ROSE HILL LANDFILL MODEL 20 30 40 LEAKAGE 50 60 70 CHECK 80 90 100 HEAD 110 120 1 23 IQ 100 5 001 37E-OU 0 130 100 001 0 0 1 4 0 - 1 - 1 1 - 1 - 1 i i i i i i 1
ISO 1 10 0 1547E-05 01 10 1 1 160 04642 200 200 1 1 i it
1QO 190
CARDS I THROUGH 19 - CODING SHEET
CHEAD
100 110 120 130 131 132 140 141 142 150 151 152 160 161 162 163 164 165 170 171 172 173 174 175 176 177 178 179 1BO 101 190 191 192
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 539
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 58
25
25
25
25
25
25 621
25
25
25
25
25 662
25 25
25
CARD SET 2 - STARTING HEAD MATRIX (FT)
193 194 IVb 196 197 190 200 201 202 210 211 212 220 221 222 223 bull 224 225 230 231 232 233 234 235 236 237 23B 239 240 241 250 251 252 253 254 255
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 23 25 25 25 25 25
25 25 - 25 25 25 25 25 25 25 25 25- 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 - 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25
25 25
25
25 25
25 25
25 25
25
25 25
25
25 25
25
25
25
25 25
25 25
25
25 25
25 25
25 25
25
25
25 25
25
25 25
CARD SET 2 - STARTING HEAD MATRIX (FT) - continued
STORC 1512 FRI 19 FEB 82
100 110 -1 -1 - 1 - 1 0 0 120 130 140 ISO 160 170 100 190 200 210 220 230 240 230 251 260 261 262 263 270 271
CARD SET 3 - STORAGE COEFFICENT
LEAK
100 110 120 02 130 _ 18 02
I ltu 18140 025 150 02015015015 19 deg25
02 160 022 bull-laquo- J1 5 j 1 z laquo- l^
170 015 180 016 laquo02
190 016 OE025
200 02504019022021025 2 5 i S lt03 0252i2 n
230 030 deg23 deg2 deg2 deg2 -02023023 240 022 250 022025025 02
027043 013025
30() 025025025 310 025031 320 024025
CARD SET 5 - AREA OF STEAMBEDAREA OF NODE
120
Appendix F
Bibliography
121 BIBLIOGRAPHY
1 Agpar MA and 0 Langmuir Ground-Water Pollution Potential of a Landfill Above tne Water Table Groundwater V 9 No 6 1971 pp 76-96
2 Allen William B Hahn GW and RA Brackley Availability of Ground Water Upper Pawcatuck River Basin Rhode Island USGS US Government Printing-office GS 66-624 19bb
3 Annual Book of ASTM Standards Part 31 Open Channel Flow Measurement of Water and Waste Water by Weirs D 2034-68 1975
4 Annual Book of ASTM Standards Part 19 Infiltration Rate of Soils in Field Using Double-Ring Infiltrameters D 3385-75 1975
5 Baeaecner MJ and W BacK Hyarogeological Processes and Chemical Reactions of a Landfill Ground Water V 17 no 5 1979 pp 429-437
6 Beck WW Dunn AL and Grover H Emrich Leachate Quality Improvements After Top Sealing1 8th SHwRD MERL Symposium 1982
7 Beckman WK Transient Modeling For Estimating Sustained Aauifer Yield master thesis presented to the University of Rhode Island Kingston RI 1978
8 Bhattacharya PK and HP Patra Direct Current Geoelectric Sounding Elsevier Publishing Co New York 1968 135 p
9 Bouwer H Ground Water Hydrology McGraw-Hill Book Co New Yoric 1978 p 378
10 Braids 0 Cocozza pound Fenn D Isbister J Rous P and B Yarc Procedures Manual for Ground Water Monitoring at Solid Waste Disposal Facilities Environmental Protection Agency530SW-611 Cincinnati Ohio 1977
11 Cartwright K and MR McComas Geophysical Surveys in the Vicinity of Sanitary Landfills in Northeastern Illinois Groundwater V 6 no 5 1968 pp 23-30
12 Cartwright K and Fd Sherman Jr Electrical Earth Resistivity Surveying in Landfill Investigations Reprinted from Proceedings of ohe lOtn Annual Engineering and Soils Engineering Symposium Moscow Idaho 1972
122 13 Clark TP Survey of Ground-Water Protection Methods for
Illinois Landfills Groundwater V 13 no 4 1975 pp 321-331
14 Dunne T and LB Leapold Water in Environmental Planning WH Freeman and Company San Francisco 1978
15 Faro DG Upgrading Hazardous Waste Disposal Sites Remedial Approaches US Environmental Protection Agency500SW-677 Cincinnati Onio 1978
16 Fenn DG Hanley KJ and TV Degeare Use of the Water Balance Method for Predicting Leachate Generation From Solia Waste Disposal Sites US Environmental Protection Agency530SW-lfa8 Cincinnati Ohio 1975
17 Geisser 0 An Electric Analog and Digital Computer Model of the Chipuxet Ground Water^ Aquifer Kingston Rhode Island master thesis presented to the University of Rhode Island Kingston RI 1975
18 Hahn GW Groundwater Map of the Narragansett Pier Quadrangle Rhode Island Rhode Island Water Resources Coordinating Board GWM 5 1959
19 Hemsley William T Koster C Wallace Remedial Technique of Controlling and Treating Low Volume Leachate Discharge USEPA National Conference on Management of Uncontrolled Hazardous Waste Sites Oct 1980
20 Hughes GM RA Landon and RN Farvolden Hydrogeology of Solid Waste Disposal Sites in Northeastern Illinois Final Report to US Environmental Protection Agency PUD SW-l^d Cincinnati Ohio 1971
21 Keller GV and FC Frischknecht Electrical Methods in Geophysical Prospecting Pergamon Press New YorK NY 19bb
22 Kelly WE West Kingston Landfill An Evaluation of Its Effect on Ground-Water Quality Rnoae Island Water Resources Board Water Information Series Report 1975
23 Kelly WE Geoelectric Sounding for Delineating Ground-Water Contamination Groundwater V 14 No 1 1976 pp fa-10
24 Kelly WE Ground-Water Pollution Near a Landfill ASCE Environmental Engineering Division Journal V 10 No EE6 Dec 19b pp nay-nyy
25 Kelly WE personal communication January 1982
123
26 Kelly WE and OW Urish A Study of the Effects of Salt Storage Practices on Surface ana Ground Water Quality in Rhode Island NTIS FHWA-RI-RD-8001 1981 54 p
27 Kimmel GE and OC Braids Leachate Plumes in a Highly Permeable Aauifer Groundwater y 12 no 6 1974 pp 388-393
28 Klefstaa G Senalein LVA ana RC Palmauist Limitations of the Electrical Resistivity Method in Landfill Investigations Groundwater V 13 No 5 1975 pp 418-427
29 Landon RA Application of Hydrogeology to the Selection of Refuse Disposal Sites Groundwater V 7 no b 19b9 pp 9-13
30 Lang SM Bierschenk WH ana WB Allen 1960 Hyaraulic Characteristics of Glacial Outwash in Rhode Island Rhode Islana Water Resources Coordinating Board Bulletin No 3
31 LeGrand HE Patterns of Contaminated Zones of Water in the Ground Water Resources Research v 1 No 1 1965
32 Palmauist R and L Sendlein The Configuration of Contamination Enclaves from Refuse Disposal Sites on Floodplains Grouna Water v 13 no 2 1975 pp 167-181
33 Pinder GF A Digital Model for Aauifer Evaluation Techniaues of Water Resources Investigations of the US Geological Survey Bk 7 Cl 1970
34 Purushattam D Tamxe GR and CM Stoffel Leachate Production at Sanitary Landfill Sites ASCE Environmental Engineering Division Journal V 103 no EE 6 Dec1977 pp 981-988
35 Remson I Fungaroli AA ana AW Lawrence Water Movement in an Unsaturated Sanitary Landfill ASCE Sanitary Engineering Division Journal v 94 no SA2 April1968 pp 307-316
36 Rosenshien JS Gouthier JB and WB Allen Hydrologic Characteristics and Sustained Yield of Principal Ground-Water Units Potowamut-Wickford Area Rhoae Island USGS US Government Printing Office GS 67-324 1968
37 Roux PH and B Vincent Electrical Resistivity Evaluations At Solid Waste Disposal Facilities US Environmental Protection Agency SW-729 Cincinnati Ohio 1978
124
38 Salvato JA Wi lk ie WG and BE Mead Sanitary Landfill Leaching Prevention and Control Water Pollution Control Federation Journal v 43 no 10 Oct 1971 pp 2084-2100
39 Sawyer CN and PL McCarty Chemistry for Environmental Engineering McGraw Hill 1978
40 Stellar RL and P Roux Earth Resist ivi ty Surveys - A Method for Defining Ground-Water Contamination Ground Water v 13 no 2 1975 pp 145-150
41 Todd OK Ground Water Hydrology John Wi ley and Sons Inc New York 1959
42 Tolman AL Ballestero AP Beck WW and GH Emrich Guidance Mannual For Minimizing Pollution From Waste Disposal Sites US Environmental Protection Agency-500SW-677 Cincinnati Ohio 1978
43 Trescott PC Iterative Digital Model for Aauifer Evaluation US Geological Survey Open file report 1972
44 University of Rhode Island Academic Computer Center CalComp Contouring Manual
45 Warner DL Preliminary Field Studies Using Earth Resistivity Measurements for Delineating Zones of Contaminated Ground Water Groundwater v 7 1969 pp 9-16
46 White EF A Report to the Town of S Kingstown Utility Survey Engineering Corp 1967
47 Zohdy AAR A Computer Program for the Calculation of Schlumberger Sounding Curves Over Horizontally Layered Media Using the Method of Convolution US Geological Survey Denver
48 Zohdy AAR Eaton GP and DR Mabey Application of Surface Geophysics to Ground-Water Investigations Technidues of Water-Resources Investigations of the US Geological Survey Book 2 Chapter 01 Washington US Government Printing Office 2401-02543 1974
hydraulic properties and the subsurface geometry enable estimates of
ground-water outflow to be made Streamflow measurements were used
to verify these outflows Contamination levels using specific
conductance measurements as an indicator were measured in wells
streams and observation holes to help delineate the extent ana
degree of contamination An electrical resistivity sounding was
conducted in a known contamination zone
The primary objective of tnis study is to determine flow
patterns in the vicinity of the landfill ana recommend possible
actions to contain or minimize the impact of the contamination In
oraer to fully evaluate these goals the aforementioned parameters
were input to a computer model to produce simulated flow patterns
under different conditions The simulated present conditions were
matched with field water table and stream flow measurements to
calibrate the model A series of simulations were then run to
evaluate flow conditions before the excavations anaor landfill
existed Remedial measures such as reducing recharge to the
landfill and implementing a slurry wall to blocx off leachate flow
to endangered wells were simulated to evaluate their effectiveness
Based on this analysis recommendations are made as to how to
minimize leachate production ano best alleviate the immediate danger
of the contaminant plume spreading to unpolluted domestic supply
wells
background
The South Kingstown landfill is in a geologic setting that is
very similiar to the nearby West Kingston landfill This is located
about 3 miles west of the South Kingstown landfill and has been
studied to assess leachate effects on groundwater quality using
specific conductance as an indicator of contamination levels
(222ltt) Both sites were located in abandoned gravel Quarries which
were filled in with refuse to create the landfill
In the literature numerous authors have shown that the character
of contaminant plumes from landfills are largely dependent on the
local geology and geohydrology A study on Long Island (27) in
similiar glacial material illustrates that the Quantity of flow is
dependent on the hydraulic conductivity of tne aauifer the
hydraulic gradient and the vertical cross-sectional area of the
aauifer it flows through This is expressed as Darcys Law (41)
Q = KIA
wnere Q = flow quantity
I = hydraulic gradient
K = hydraulic conductivity of the aauifer
A = vertical cross sectional area of the flow area
Specific conductance was used as a contaminant tracer to show that
the plume from the landfill flowed downgradient and vertically
through the full thickness of the aauifer A study in Iowa (32)
indicates that the size ana shape of the contamination outflow from
a l a n d f i l l can be predicted from existing geohydrologic conditions
and that the horizontal shape of the outflow extends downgradient
8
from the source and parallel to ground-water flow lines Other
parameters which control the extent of the contaminant plume are
dilution and dispersion in the aquifer and the adsorption properties
of the aauifer material (31)
The amount of leachate generated depends largely on the amount
of water that infiltrates through the landfill to increase tne water
content of the refuse in the landfill The precipitation recharge
that percolates down through the unsaturated zone to the water table
moves in a vertical direction (35) Surface runoff soil moisture
storage losses and evapotranspiration account for tne precipitation
that is not transmitted tnrough the unsaturated zone of aeration
(3315) Upon reaching the saturated zone the water enters the
ground-water flow system Ground-water mounding has been reported
in landfills due to the decreased hydraulic conductivity of
compacted refuse relative to surrounding aauifer material (20)
Chemical processes within the landfill leachate outflow and
surrounding soil cation exchange capacity relative to water duality
of the surrounding aduifer have been studied in Pennsylvania (1) anu
in Delaware (5) A procedures manual for ground-water monitoring at
solid waste disposal facilities was developed by the US
Environmental Protection Agency (USEPA) (9)
Several reports have been written that investigate site
selection design criteria and remedial measures to correct
leachate problems (29) A survey of ground-water protection methods
for landfills in Illinois studies relationships to the water table
theory of liner installation and monitoring devices (13) Sanitary
Landfi11-Leaching Prevention and Control presents a review of
preventative methods such as means to minimize infiltration
interception of ground-water and other pollution control measures
(2 37) A study in Pennsylvania on actual measures implemented to
collect and treat a landfills leachate discharge presents a site
specific study (19) Leachate Quality Improvements After Top
Sealing1 shows that by minimizing infiltration at a landfill in
Connecticut the outflow leachate water quality can be improved
dramatically and contamination plume reduced significantly (6) The
most comprehensive reports on remedial approaches to upgrading waste
disposal sites and ground-water protection methods have been
compiled under USEPA contract (1542)
To assist in evaluating remedial measures the US Geological
Survey (USGS) computer model Iterative Digital Model for Aduifer
Evaluation was used It was originally developed as a model for
simulating two-dimensional aauifer problems (33) It had been
updated since its original development to accomodate different
options (43) This model has been applied to glacial outwash
regions in Rhode Island (717)
10
Description of Study Area
A map of tne landfill area (Fig Z) was obtained from tne town
of South Kingstown The excavation to the west of Rose Hill Roaa
the landfill area directly to the east and the presently operating
area to the east of the central stream comprise tne overall study
area This study will concentrate on the west landfill area whicn
has recently reached capacity and been closed to further dumping
This site received mixed refuse for the past 15 years The depth of
the excavation where the landfill presently exists was approximately
to bedrock in some places Tne exact depths of landfill material is
unknown
The landfill cover has been graded and sloped generally eastward
to convey surface runoff to the eastern side A sandy soil that was
excavated locally was used as tne cover material The northern
section has a vegetation cover and the recently filled southern
section has been seeded and mulched The six monitoring wells W
NW NE EC SE SC were placed by the town of South Kingstown to
provide water quality information
Referring to Fig 2 the west excavation stream drains the area
created by the excavation to the west of Rose Hill Road and flows
throughout the year The central stream drains a small watershed
area which lies to the northwest of the landfill and drys up during
part of the year These streams flow into the Saugatucket River
which flows throughout the year and is larger than the west and
central streams combined
11
The USGS Groundwater Map (18) was initially consulted to proviae
information on the ground-water flow patterns (Fig 5) and the
geology of tne area (Fig 6) The surficial geology borings and the
vertical geologic cross-section at the base of the study area
indicate shallow water table and bedrocic and a nearly constant
saturated thickness (18) Boring logs at the W well ana a point
approximately 150 feet south of it indicate glacial outwasn material
which is primarily sana with a trace of gravel over bedrock at a
depth of approximately 33 feet Borings at the east landfill area N
and S monitoring wells indicate the same aquifer material
(Appendix B)
The ground-water map developed by Hahn is taken as
representative of conditions existing prior to the excavation of the
I l andfill (18) This indicates water-table contour lines that run in i
a general northeasterly direction This means tnat flow was
originally in a southeasterly direction However contamination of
domestic supply wells on the west side of Rose Hill Road has
occurred (Fig 3) strongly suggesting that the original flow pattern
has been altered by the excavation to the west of Rose Hill Road and
the landfill to the east of it Domestic supply wells were formerly
located directly to the west of Rose Hill Road but were aoandoned
when they became contaminated from landfill leachate New wells
were located to the south and west away from the contaminant plume
of tne landfill In addition a well located at the northeastern
corner of the landfill was contaminated and a replacement located to
the east of Us former location on tne opposite side of the central
12
Legend scale 124000
mdash-40 mdashground-water contour elevation
Fig 5 Ground-Water Map
13
Legend feet
TILL
Fig 6 Geology Background Map
14
stream This second wel 1 also became contaminated Domestic supply
wells located near tne northwestern corner of tne landfill and
approximately 300 feet south of it nave remained uncontaminated
These well locations serve as an indication of tne extent of the
landfill contamination which is largely dependent on the groundwater
flow patterns To furtner investigate this problem and provide
substantial information on which to base the geohydrologic analysis
field studies of the area were conducted
15
Field Studies ana Procedures
A map of the lanafill and an aerial pnotograph of the area were
obtained A tracing of these maps superimposed upon another
delineates stream landfill and monitor well locations (Fig 2)
The field investigation concentrated on the west landfill area ana
its aajoining streams ana monitor wells The east landfill area and
the three monitor wells in that area are induced in the latter
phase of the study in oraer to expand the model area
A traverse which establishea tne monitor well elevations was run
using a Carl Zeiss level These were originally sitea in by the
town of South Kingstown using a local USGS reference datum number 40
(18) The wells of known elevations then served as benchmarks for
referencing adjacent stream elevations This in combination with
the depth to water table measurements at each well enables tne
water-table surface geometry of the area to oe visualized
Water-table measurements of the west landfills wells were recordea
over a ten month period to record fluctuations (Fig 7 Table 1)
The east landfill areas wells were monitored for a five month
period Using a given water-table condition a ground-water map was
developea of the area (Fig 4) This indicates an outflow from
the landfill primarily in a southeasterly direction and partially
in a southwesterly direction
Additional bedrock and water-table information was ootainea by a
seismic refraction survey at several locations along the landfill
perimeter A Bison Model lb70C Signal Enhancement Seismograpn was
used to maxe the surveys Lines were run (to a length of kOO feet)
16
17
w s p bdquo S bdquo s S S a laquolaquo _
s 2 8
V
r bdquo
3 s a
-R s
S
S 3
t
raquobullraquo
S
5
K
r
~
3
K
pound
7
S
bdquo3
C 5 S
shy raquo S s
1 3 s 3 2 5 ^ bull
5 m
s o
^ 3
raquo
--
R bull 5
s pound J O s
5 a 3 7 3 m
5 s a ^
iraquo a s rlaquo
M ^
^ c o 2 5 s 3 a S R
rd 3 y a O =J
^ bdquo
JJ s s 3 bull ~ I
~ s 5 3 a s a
(Ogt (U
2
-t =
r s s in
5 y
a s
5
3
s
5 a
^ a
3 a 51 a bullbull
sj 5 Ml
3 a bull
s raquo
a
0)
0
^ mdash
a j -
-3
C
g S
S
bull a
-
~ 3 o
2 s s 3 a bdquo s s $ Al s
(1) = $ s 3
S
c a a
3 e 5 s N s S a - 3 = s s a 5
a s s - 3 S shy
4
0
a s
bdquo tfH
bdquo
3 a
bdquo
s a
e bullfl s i s s a s a
3 nt
s s 3
g laquo s3 a
~ J s 2 a s o s S s 3 a a j laquo s o s
3 bull laquobull
2 a 7 3 a 3 a ^2
s mdash 5i o
bull bull
mdash
3 o
ss a
fc mdash
3 1-sect m ishy n
18
in both directions to provide a check and permit accurate estimates
of the depth to bedrockThe seismic results allow approximate
interpretations of the depth to the water table and bedrocK thus
permitting an estimation of the saturated thickness Ground
elevations at the location of the seismic surveys were determined
from a topographical map and field siting From this information
water table ana bedrock elevations estimates were made Bedrock
contours are listed in Fig 8 In addition a table which
summarizes the seismic refraction results for the unsaturated
saturated and bedrock layers velocities and depths at each survey
location is presented in Table 2
Scream gauging stations were established on the two streams
bordering the west landfill (Fig 9) Three stations were placed on
the central stream These provide information on the influent or
effluent condition of ground-water flow in the upper sections of the
stream and ground-water baseflow from an area adjacent to the
landfill into the stream (Table 3)
The stream gauging stations used were 90deg V-notch weirs The
weirs located in the SE and SW positions were placed in the
streamoea with a liner of plastic upstream to minimize underflow
The weirs located in the NW and E positions were cut to fit in
recesses of concrete culvert pipes Concrete plywooa interfaces
were coated with roofing cement to minimize bypass flow Upstream
water pressure and a snug fit hold the plywood sections in place
All weirs were implaceo according to AigtTM reouirements and flowrates
calculated using the standard 90deg V-notch formula (3)
19
N
seepage West observat ion Landfill hole
Area
Legend landfill limit excavat ion limit
copyWNWNEECSESC monitoring well locations
= = = unimproved road -- WNES-number
seismic refraction locations
-40shy approximate bedrock contpur elevation
feet
Fig8 Seismte Survey Location
20
c ^-^ c4j ^laquoc in -=r 3shyjj bull pn f- 4-gt bull in in OjJ bull bull a jo bull bull O JJ
co CM o on on CO CM CTNVO VO co CM o on on Q gt_x rH oj on a oj on a - rH oner
rmdash on sr i i
M z Z
gt gt gt
X-N CO laquomdashv CO CO bull igt gt bull
1 gt fc^gtgt bullbull ^ ^ ^
C 4-gt O t igt O J- 4J O H m o o o 3 bullH CO O rH in 3 bullH co vo o in 3 ~ 1 i-k -i ^trade fj rj ui ij o CO o n o rH =r co o n vo vo vo co o bullv O O O
O raquo On-3 rH O -bull- rH ON in _ IH in oj - rH bull rH VO OrH bull rH On ON pH d)u CO -UCO 4J OJ CO 4-gt gt
C mdashbull gt CM gt CM H-l O CO
v- ^^ N C 0
bull0 N CO
4-5 -0 _c^gt in in CO CO
C x~ c -^ t-oo in i 4J j_gt 41 4J bull 9 bull bull 4J bull
o j ON O O 3 (0 O4J O ON ON QJJ t~-^3- OJ 4-gt L
CO CM trade CO CM rH rH OJ co CM oj on Q ^ _ CO 3~Q-- n 45 Q mdash OJ OJ OJ C (0
1 11 3 nZ 2CO
gti gt gt CO CO CO ^-x m -s CO
rH rH ^ ro^^ bull gt bull ^ igt gt bullgt gtgt bull r O -Q 4Ji JJ O 5- JJ O pound- ^ O 4) oj o on (0 CO
3 bullH CJ O O in 3 bullH CO Cmdash VO on 3 pound-laquo H CO o n in inco co o n ma- r co g^ 5sect^ o
o rH on oj O bull- rH ONCO L O_ rH OJ VO M
rH bull rH =t rH bull - OJ T CO CO M CO 4-gt rH CO -U rH CO 4-) s
uits
CO 4-gt 4-5 T3 gt CM gt CM gt CM cc CO CO CO
3 3gt oa tlp^ CO O CM O gt 4J O 40 i 3 r+ k C pound JS
CO pound
^^ s -bullgt cmdash on poundZ VO CTI trx 4J 4J 4J
) bull bull bull Q Q Q Q4J 3shyc O-JJ CTgt OJ OJ Q-IJ inco on CO CO CO o co CM oj on co CM oj on co CM on
Q Q QON^ Q bullH Q^
rH rH 4J rH
O bullraquo L Z bull CO CO CO
i gtgt rH oj on gt tgtshyCM ^ cO^-s CO ~ CO
CO CO J X fc^_ bull^gt bullgtgt bull gt gtgt bull gt CO
j_ jJ O pound- Jj -P O Li deg =fObullH co on f- ^ 3bullH CO CO O in 3bullH CO
g^ -^2
poundsect HO
eis
mic
3 CO in in in in in in co o n co o n
o -^ r oj in O rHCO CO rH bullrH bull rH =T OrH bull rH OJ f-CO 4J bull- CO 4J rH O0) J-)
gt CM gt CM gt CM 4J
CO N_^ m^
bull OJ
t t poundshyCO CO CO CO rH J3 gt r-t oj on gt r-i oj on gt gt r n o j o n
lto co lto CO T bull ii-4 laquomdash bullmdashH
bullo CO L L 0)
CM CO cc
21
N
545-594
seepage observation
hole West Landfill
0NE I47-509
Area
Weir 45
i487-531
0 EC Al3-467
Legend bullmdash landfill limit -bull---excavation limit r-s stream
copy WNWNEECSESCSEN monitoring well locations
= = = unimproved road
Weir location and elevation
feet
Fig 9 Weir Locations and Wate r Level Ranges
22
JT NO
S shy S
O
bull ry m
oa
NO
(M raquo 1 03 or NO m
JT O O raquo
O NO 03 (j
PW tn in ^4 fraquo
m CN) f O O (M Oj
mdashraquo 3 M
s cshy -raquoraquo
o in in ^
rjO
laquobull NO ON
o bull-lt ^
H fy (NJ
tjgt
1 4 03 O
o
o
03 CM
in0
0
7 raquo
9gt
IM i iev NO
i in
i ru
i 0 rsi -or^
sO NO
CO O
03 raquo
1 O3
pound o ro CNJ
03
tn B OJ
o 03
m oi
NO
(M
r
(M
CO i M 03
m N ltn ~+ ltM -
QJrH
O M O ^ ^r-
oo m
8 a
m
^ NO
8 fNl
rshy03n
m - in
o laquoO
bull3 as m o 03 03 4
i O
i ^
shy
O
ltM bull^
ON f tn H 1 4 raquo4 i-4 H P-t
^^ lt-l
r-laquo
^ 1 1 1 1
pound raquoraquo O)t o gtz
bull bull ltbull
lt2
1 pound OJ
3 oi g bull
pound
1 pound laquolt bull
3 bull o a
pound
5 laquo15
f bull 3 Jl s
5bull 1 5
23
A field study to determine the infiltration capacity of a
section of tne landfill topcover was conaucted A modified version
of a double ring infiltrometer was used to study infiltration rates
(4) The cylinder diameters useo in this study were 8 inches and 18
inches A constant head of 6 in was maintained in the
infiltrometer and rates of infiltration were determined Tnese
results and an analysis of surface infiltration into the landfill
are included in tne analysis and discussion section
Specific conductance levels in the monitoring wells in the
streams bordering the landfill and at observation holes near the
landfill were measured (Fig 10) This is a good indication of the
mineralization of water (39) Specific conductances were measured
intermittently over the ten month period to develop a picture of the
extent and degree of contamination in the wells (Fig 11 Taole4j
and in the surface contamination monitoring locations (Fig 11
Table 5) A comparative standardization of the Beckman (short and
long probes) and YSI specific conductances is in Appendix C
A surface electrical sounding using the Schlumberger array was
conducted adjacent to Rose Hill Road at the R-l location (Fig 12)
in an attempt to delineate the vertical extent of the contamination
zone Well W was used as a centerpoint and a reference for
water-table depth pore water conductivity and depth to bedrock A
Schlumberger array electrical resistivity sounding was also
conducted in an uncontaminated area at tne R-2 location (Fig 12) to
provide a comparison background interpretation A seismic
refraction survey N-4 was conducted at the same location (Fig 8J to
24
N
excavat ion
Seepage West observat ion Landfill hole
Area
Stream 1 Seasonal observation 0 EC
hole
East Stream2
Legend sw Weir landfill limit j--1--^ excavation limit
copyWNWNEECSESC monitoring well locations
== unimproved road
feet
Fig 10 Surface Contamination Monitoring Locations
25
8000T
7000
O bull U) W6000
Legend
0 sc A NE O W
A SE O N W
a EC
1 O N D J F M M
Time months Flg11 Flucuatlon In Specific Conductance in Wells
26
Table 4 Specific Conductances in Wells (pmhoscm at 25degC)
West East Landfill Landfill
Date NW NE EG SE W SC N E S
81581 851 938 236 2356
102981 171 3268
11381 3268
111081 304 988 1100 258 3800
111481 426 2736 1216 186 4560
111781 304 3610 433 389 4560
121981 380 1406 129 103 380
1982 160 152
31582 274 760 1064 61 334 8000+ 182 53 84
52182 450 1500 1125 112 712 8000+ 175 255 150
52282 425 1320 1200 110 850 180 320 170
27
O
ct c r i c o o o o o c M o m o in CO CM unp^
3bull t- fmdash o^ co tmdash vo co in co cmdash co in a
bull bull1 1-1 trade4 rH rH^ CO 4)2
~ plusmn4J o O CM ^_
o n CO vO J oraquo 0C0M
cu rH rH rH rH rHin tmdash
3 iCM 4J
^j CO CO
E O0 ltU -H n o c E
See
pag
se
rva
t
rH O in 0 0 O O 0
O o x rH Cmdash
0 0n
cu rH mdash O tmdash X o o o o c o o o o r H r H i n o i n i n o O
bull L in oo co oo oo o cy cr o rH CM o cr ONc fcJ bullH on en m m rn c^n rH rH rH0 pound CO 3 CO
t CM0gt s o o o in rA n ^o oo in tmdash oo 0gt zr =r a- JT JT$_
T)C CO
~ E CO ^ _bdquo ltu CO g r H r n c n i n o o r H r H
vgtO ^D O ^^ ^O CO ^^ ^^ JJ 2 4) rH rHCO t
c CO
CO c 9) rH 0
CO -^ C c CO ltuo famp O trade t iH
0
bullo co n ^
oS
o ^^ bullH m
i co rn O CQ O1 CO CO 4) c2Q 3
CO
mdash^ bull cmdash CMin 1 gt rH vO vO O CTgt CO
s CTgt CO OO Ogt Craquo- tmdash cu O CO rH z 0
bull_bulllaquo
H bull L o in r in o oo in 3 rfy ff^ tir f^ CO C^~
4)bull
Z 3
^ ^ ^ ^ H r H r H r H r H rH r H C O r H C O a O C O a O a O C O C O r H i H r H CO OO - gt 0 0 ^ - gt ^ raquo - ^ ^ 1 - gt ~ gt - C O C O O O
U ^ raquo ^ - ~ raquo O ^ ^ O t ~ C O r H - r r ^ - ^ ^ JJ r H C M v O r H r H r H r H r H C M C M r H i n c r gt rH CO CM gt laquolaquo - - -^ bullmdash mdash bullraquoraquobullgt -v -v ^^
~ v O r H r H r H r H r H r H r H r H lt M C M C M CM O O r H r H r H r H r H r H r H r H r H r H r H r H rH
in rH cmdash
CO vo
CO vO
41 rH CO
CTgt rH raquo CM rH
cn CO
o 0 rn
CO cmdash
tmdash fshy
CM ao
iT rH
m
ogt ao
O o vO
CO t-
tmdash Cmdash
CM CO
rH CM
I
rH CT
O vO in
CTgt
in c^
CM ao
CM CM
in
-
bull
CO bO C bullH T3
cy ~
_
CJ E 3 ^ n c bullH
1-1
CO
^H
28
excavation
West Landfill
Area
Legend bullmdash landfill limit -bullbull--bullexcavation limit r~~s stream
copy WNWNEECSESCSEN monitoring well locations
= == unimproved road
electrical resistivity sounding
feet Fig12 Electrical Resistivity Sounding Location
L
29
allow estimates of depth to water table and bedrocic to be made
Soundings were carried out to 500 foot electrode spacings to insure
that hredrock was penetrated and to facilitate interpretation These
results and a discussion of the soundings interpretation are
included in the analysis and discussion section Schlumoerger
resistivity soundings were made using a Soiltest R-bO unit
30
Model Development
The USGS Iterative Digital Model for Aauifer Evaluation was
usea to develop steady state flow models of the study area (43) A
flow chart of the computer model and a brief explanation of the
subroutines usea is presented in Appendix D The stream locations
elevations and aauiferlandfil1 geometry and hydraulic properties
were input to the model to compute head values at each 200 foot
grid spacing node (Fig 13) The input data which is for the
existing excavation and landfill conditon is listed in Appendix E
The head values that are computed at each grid space are in turn
loaded into the CalComp plotting routine (44) where a grid spacing
is setup with the computed head values at each node The contouring
program linearly interpolates between these head values and
generates a contour map The computer simulated ground-water
contour map for the excavation and landfill is presented in Fig
14
The streams in the model generally serve as controlling boundary
conditions When using computer simulated geohydrologic models of
an area choosing the boundary conditions for the model that are the
same as prevailing conditions in the field is a critical step in
model development Extending the models boundaries to areas in the
field that have a minimum influx of ground-water across them
simplifies the proolem of calculating fluxes from outside the model
area The eastern boundary is bordered by glacial till which has a
low hydraulic conductivity estimated to be 67 ftday(2) This
contrasts to the high hydraulic conductivity of glacial outwash that
makes up the model area of approximately 107 ftday(3036j
31 N
o 9
bullO O
32
33
The Saugatucket River serves as the controlling boundary on the
east A small drainage area directly to the east of it provides a
minimal influx
Beyond the moaels northern boundary the glacial outwash valley
extends to the base of a till covered h i l l on the western half ana
on the eastern side extends along the Saugatucket stream Due to
the relatively large drainage area that lies upgradient from the
northern boundary a recharge flux eduivalent to 10 inyr over the
drainage area on the till hill and outwash area north of the model
area was input as underflow (Fig Ib) Part of this was input at
each northern boundary node Till has a lower infiltration capacity
than outwash so more of the precipitation w i l l be transmitted as
overland runoff resulting in a lower ground-water baseflow The 10
inyr of recharge that results in a ground-water inflow from the
combined till and outwash region represents an estimate that is
smaller than the 14 inyr recharge for glacial outwash areas in
Rhode Island (25)
The glacial outwash valley extends beyond the western boundary
No significant ground-water recharge flux was estimated at this
boundary A relatively low ground-water gradient exists to the west
of this which does not provide a significant flux across this
boundary Tne southern boundary is basically the outflow region for
the area and therefore would not reauire any ground-water flux into
the moael area across this boundary This boundary was set south of
the point that the streams in the model merge together Therefore
the streams which lie to the north of it are the controlling
34
scale 124000
Fig 15 Northern Drainage Area
35
boundary conditions The flux out of the downgradient outflow
region approximately eauals the influx from precipitation recharge
and boundary influxes
When tne stream configuration in the moael area are reviewed it
can be seen that they comprise a large portion of the boundary
area The screams can act as sources or sinks for water in the
model thus providing to and removing water from the aquifer The
leakance option was used in the model which provides for a confining
bed and aouifer area beneath the stream to be input
The leakance is defined as the hydraulic conductance of the
streambed divided by the streambed thickness which in this case is
taken as 1 foot The leakance value at each streambed node
restricts the flow between the aduifer and the stream The
streambed hydraulic conductivity is typically 01 the value of tne
hydraulic conductivity of the aduifer (717) The value 107
ftday was used for a streambed conductivity based on a value of
107 ftday for the aquifer The aduifer and stream hydraulic
inputoutput exchange at eacn node is calculated by initially
finding the difference between the initial field stream head
elevations and the computed head elevation values at the
corresponding nodes This head value is then multiplied by the
(Leakance value at each node) x (stream area of each node)
Therefore if the aduifer head was lower than the stream head the
stream would act as a source of water for the aquifer and vice
versa
36
Tne leaxance input at each stream node is the ratio of the
actual field streambed area in each node to the area of each node
which is 200 ft x 200 ft = 4 x 104 ft2 The west
excavations stream width is approximately 3 ft central 4 ft and
east 5 ft Therefore if tne west stream traverses the node
directly without meandering it presents a leakance of 3 ft x 200
ft4 x 104 ft = 015 Leakance and streamhead values were
input at each node to set up the stream flow parameters in the
models
A recharge value of 14 inyr over the entire area was input at
each node This represents a value of precipitation that is
transmuted into tne ground-water rather than being directly
evaporated evapotranspired through plants or overland flow
runoff The precipitation recharge flow from the stream into the
aauifer and boundary fluxes provide the model witn input flow
parameters
From analyzing the available information it was determined that
the study area lies within a glacial outwash area with a relatively
shallow bedrock The seismic survey around the landfill generally
indicates a depth to bedrock below the land surface of approximately
29-43 ft with corresponding saturated thicknesses of 19-33 ft as
seen in Table 2 This agrees with borings from tne USGS groundwater
map in the stuuy area (18j The seismic survey was run at a low
water table condition which was several feet below the high water
table level (Fig 9)
37
High water-table saturated thicknesses were used to develop
model parameters For the purpose of this model study the saturated
thickness was set at 30 ft except in the vicinity of well W where
there is a bedrock high (Fig 8) At this location a high water
table saturateo tnicxness of 8 ft was estimated In tne vicinity
the seismic survey was conducted the bedrock elevation at this
location is the highest and the saturated thickness the least Tnis
can be seen by an east-west cross section of tne landfill (Fig 16
The boring log for well W indicates a sand trace gravel outwash
material (Appendix B) Boring logs at the eastern landfill area N
and E indicate similar material On this basis the hydraulic
conductivity was estimated at 107 ftday (3036) Witn the
exception of the landfill and the bedrock hign areas the
transmissivity values were set at 107 ftday x 30 ft = 3210
fto day From the literature the hydraulic conductivity of the
landfill material was estimated at I ftday (19) The
transmissivity of the landfill material in tne nortnern section was
estimatea at 1 ftday x 30 ft = 30 ft^day or approximately two
orders of magnitude lower than the outwash In tne landfills
southern section the original excavation was not as deep as in the
northern parts The landfill material was estimated to makeup only
one half tne saturated depth the remainder being the original
glacial outwash material (Fig 17) Therefore the transmissivity
at the southern end was estimated at 15 ft x 107 ftday + lb ft x
1 ftday = 1620 ft^day These values were graded into the 30
ft^day values at the landfills northern halfway point These
38
were input as transmissivity values to the model at their respective
locations This model did not use the water taole option so
water-table fluctuations did not affect the transmissivities
39
O
-8 Oi0
co o
CO
o Oin
3
O or
bullo c 10
ogt o laquorf o
c o o e 0i
CO to o k O
co CO LU I
09 O
bullo c 01
CO
C9
UO|JBA9|a
40
o ltD
a o co
o10
o o
C O
coI co co O w O
o CO I
JC
l_ o Z
bullo c 09
CO
oin uo|BA8|a
Model Calibration
A simulation was run using the initial estimates of stream
parameters aquifer and landfill hydraulic conductivities
transmissivities boundary and recharge conditions to approximate
water taole conditions in tne fiela Initially the existing
condition of the excavation area to tne west of Rose Hill Road and
the landfill to tne east were modeled in order to calibrate the
model to current field conditions as shown on Fig 4 The simulated
well values (Fig 14) fall within tne range of field values (Fig
9) The resulting contours also provide an approximate matcn This
can be seen by comparing Fig 4 with Fig 14 An additional check
was to match the flow loss and gain in the streams between tne weirs
in the central stream which w i l l be discussed later The
simulated flow value from the excavation drainage stream is the same
as that measured at the SW weir location Having calibrated the
model by approximately matching well water levels nead contours
and scream flow values different field conditions and possible
remedial measures can be simulated
When the model grid was laid out over the study area as viewed on
Fig 13 the stream configuration rarely traversed the grid nodes near
their central axis When the stream locations were input to the
computer the information was documented as crossing the central axis
of the grid nodes The result of this is a slight aberration when
the actual stream configuration is laid over the computer graphics
head contour output The streams dont always cross the groundshy
water contour at the logical location Rather than modifying the
actual stream configuration to adjust then to the computer output
their actual locations are presented
42
Simulations
i The primary focus of the computer modeling is to analyze flow
patterns under changing conaitions in the near vicinity of tne raquo
landfill The study areas overall flow patterns as they exist
today are first presented in order to realize the lateral east-west
head contour lines between the stream that directly borders the
landfill on the east side and the SaugatucKet stream (Fig 14)
This indicates a general southerly flow direction in that area As
different conditions are modeled these contours generally maintain
their east-west orientation In order to facilitate interpretation
of flow patterns in the near vicinity of the landfill flow patterns
to the west of the stream that borders the east side of the landfill
r are presented in the subseauent models
L- Natural Conditions
The results of modeling the original natural conditions are
shown in Fig 18 The excavation and stream to tne west of Rose
Hill Road and tne landfill did not exist in this simulation The
southwestern boundary consists of a drainage stream that was
delineated using an aerial photograph and stream elevations were set
using the topographical map The USGS ground-water map (18) was
used to estimate head values between the west excavation and north
streams These were input to the model as constant heads on the
models western boundary The resulting simulation generally matches
the southeasterly flow direction that is indicated on the
ground-water map (Fig 5)
A3
Legend
x-^- stream 400 = = = unimproved road
I f ee t
Fig 18 Natural Conditions
44
Excavation Without Landfill
The condition of the excavation to the west of Rose Hill Road
with its resultant drainage stream without the landfill was modeled
next (Fig 19) The extent of the excavation ana the location of
the new drainage stream were delineated using the aerial
photograph The west stream elevations were sited in the field and
used in the model The concept of a confining streamoed layer was
excluded in tne excavation drainage stream under the concept tnat no
significant organic layer had been built up within the 25 year
period that the excavation had been initiated Head values between
the west and north stream boundaries were interpolated and input as
constant head values on the northwestern boundary The west
excavation drainage stream creates a condition that alters the
natural ground-water flow patterns by creating a more southerly flow
condition the drainage stream providing a more immediate surface
outflow in that area
Landfill Without Excavation
The hypothetical case of a landfill without the excavation was
modeled next (Fig 20) The low hydraulic conductivity zone of the
landfill changes the natural flow conditions and creates noticeable
mounding This is evidenced by the decreased spacing of the head
contour lines and deviation from the lateral contour lines of the
natural conditions and higher head values (Fig 21)
45
Legend
excava t i on s t ream
400 unimproved road
f e e t
Fig19 Excavat ion without Landfill
46
Legend
landfill limit
bull - s t ream 400 copy WNWNEECSESC
monitoring well locations f ee t bullbull-bull=bull unimproved road
Fig 20 Landfill without Excavation
1
oin CM
bull
m u
0)rf
oO
bullo 9
bullo 9
o rf o o CO 1
lt0inO O
T ^ogt
c o
47
o9 aI 0)
ot_3 O laquolaquo coO bull3 OJ oX
bulla caj
CM
UO|IBAraquo|
48
Landfill ana Excavation
The condition of tne existing landfill and the excavation with
the dam is the next condition modeled (Fig 22) The ground-water
elevations used to calibrate tne model correspond to an actual high
water table condition Between the NVJ and pound weir a streamflow loss
of approximately 102 gpm occurs aoout 60 percent of this flow is
lost at the dam site which maintains a head of b-6 feet over an area
of approximately 1800 feet^ This approximates a field value of
1144 gpm influent to the aduifer between the NW and E weir on ]2
December 1981 (Table 3) From the E weir to the SE weir a net
increase in flow occurred of 74 gpm which corresponds to field
increase of b62 gpm
The surface runoff from tne landfill flows primarily toward tne
eastern side of the landfill Increases in water-table elevations
on the eastern side after heavy rains such as the 11 November 1981
storm indicates that this runoff increases outflow gradients to the
stream and therefore increases streamflow Surface runoff input is
not modeled which explains in part why field stream inflow values
are slightly higher than model predictions especially for periods
after a storm has occurred The flow from the SW weir located at
the southern end of the excavation represents drainage outflows from
that area The net flow calculated in the model was 140 gpm
which approximates field conditions of 1642 gpm on
December 9 1981
49
d f l f reg N E
shy
Legend
landfill limit -bullgt-bullgt- excavation ^-N_X- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road
-40mdash approximate groundwater contour
400
feet
Fig 22 Landfill and Excavation with Dam
50
The modeled flow patterns suggest how the various contamination
zones around the landfill have developed to their present state
They indicate a flow to both the southeast and southwest on their
respective sides of the groundwater divide Evidence of a
southwesterly contaminant flow is presented when the continued high
specific conductance contaminant level in tne observation seepage
hole is realized (Table 5 ) In addition the specific conductance
increase in the west excavation stream is evidence of an influent
contamination flow
Contamination flow to the eastern and southeastern side of the
landfill is obvious High specific conductance levels in the wells
on the eastern side (Table 4 ) a specific conductance increase
between the E and SE weirs (Table 5 ) and contamination in the NE
domestic supply well (Fig 3) present conclusive evidence of
contamination to the eastern side of the landfill
An anamalous condition that exists is a domestic supply well
located approximately 300 feet due south of the landfill remains
uncontaminated (Fig 3) Flow patterns indicate that contamination
would be transported from the landfill south to this area
(Fig 14) One explanation is that a pocket of clay at the southern
end of the landfill area was discovered in the original excavation
for the landfill (lt6) This evidently prevents leachate from
reaching this wells radius of influence
51
Summer Conaitlon
As described earlier during dry months of the year the stream
that normally borders the northern and eastern side of the lanafill
may dry up as far as a point southeast of the E well Tnis
condition existed from the 15 August 1981 to the 27 October 1981
period when streamflow commenced in the northern part of the stream
yet did not overflow the north dam until 17 November 1981 This
created the present day continuous flow condition throughout the
stream These summer conditions were modeled by removing the stream
above the aforementioned location while other conditions remained
the same (Fig 23) Summer condition well water levels listed in the
model generally match field low water table conditions (Fig 9)
Because there is no stream upgradient from the landfill to provide a
stream head and infiltration through the streambed groundwater
runoff from the area north of the lanafill is the controlling flow
input In these moaels an average recharge of 14 inyr was used
which represents a yearly average The summer recnarge conditions
are prooably lower given the effects of decreased rainfall and
increased evapotranspiration during the summer months A domestic
supply well whicn exists northeast of the landfill (Fig 3) nas a
greater potential to be contaminated from the lanafill at tnis time
than when the stream is flowing Flow patterns from the landfill
are such that during an upper stream no-flow condition groundwater
flow patterns are more in an easterly direction than in a
southeasterly direction The stream would act as a source of
infiltrated water upgradient from tne landfill and provide a
52
I ^N gt i I i j i -r- -bull- bullr -T- t- -r- i- TJ JV
bullbullT laquo ^ O - laquo bdquo xi cshy
H r^~ I -~- --^ X- = mdash x^ N
^--^ A bull O^NW -v - gt-bull Ni i I _____mdash - bull laquo l - mdashmdash 1 deg I ^ltv I C
I reg NE A
Js bull vbull A ~ - v T gt- ^ ix - N
-5Z- | N TfS lV I -bull bull iA i gt gt I ^ bullr-Ky L bull 1 _- copy]wgt-- - bull- mdash - - shy
= r Y ~mdash ltmdashA A
^^-lt A _ - - - - bull Hmdash - reg EC x ^-mdash mdash I ---mdash_mdash -t-V-^N - y
I- -bull - r x i X
V ^ 7 I -v (^~~^^r ^^^
sc Emdash-bull vV JI - - - ~ r )N y- -
X - bull r bulllt
^bull^ y y Jlaquo^ - -lt shy
T s^ lt^ ^ +^-b (
X
Legend
landfill limit j-j-bullraquobull excavat ion gt^ -x- s t ream
reg WNWNEECSESC monitoring well locat ions
= == unimproved road fee t
Fig 23 Summer Condition
400
53
constant head across tne northern section of the landfill This
would tend to orient the flow in a more southerly aowngradient
direction In addition the stream which flows adjacent to the
northeastern well could provide a source of infiltrated clean water
to it which would minimize the possible contamination from landfill
leachate
Without Dam
During tne spring scream flow condition the dam failure which
occurred between the 15 March 1982 ana 9 April 1982 monitoring
periods decreased flow to the aauifer and landfill This eliminated
the 5-6 foot head difference over a 19000 ft^ area which had
created a larger area and elevation head for infiltration to occur
The condition without the dam was modeled by reducing the area
encompassed by the dam to a 4 foot wide stream channel thus
reducing the leakance value at that node (Fig 24) The flow change
from the stream to the aduifer between the NW weir and E weir
reduced the model flow loss to 50 gpm Tnis corresponds to the 9
April 1982 monitoring period which indicates a 30 gpm loss
As compared to the previous flow loss in the upper stream
sections to the aauifer the 21 April 1982 and 22 May 1982
measurements between the NW and E weirs indicate a flow gain The
streamflow conditions have changed from an influent
stream-to-aauifer condition to an effluent aduifer-to-stream
condition that increases flow downstream
54
Legend
landfill limit j--i--i- excava t ion x-gtmdash^- stream 400
copy WNWNEECSESC monitoring well locations
= == unimproved road f e e t
Fig 24 Landfill and Excavation without Dam
55
Analysis and Discussion
In order to fully understand flow patterns and Quantify leachate
outflows at the landfill it is necessary to arrive at an estimate
of flow inputs from precipitation ana upgradient sources In the
following analysis it will be demonstrated that the rainfall input
to the landfill is the factor which controls leachate generation A
calculation using the H inyr recharge over the area of the
landfill was made to estimate the leachate outflow due to rainfall
infiltration An estimated 134 gpm is generated from the entire
landfill area Simulation of the existing conditions (Fig 24)
indicates a groundwater divide in the landfill is located
approximately at the western third Therefore approximately 23 of
the generated leachate flows to the eastern side of the landfill or
9 gpm The effect of the flow input from the upgradient stream is
evident when tne summer condition witnout the stream is viewed
(Fig 23) Without the stream to infiltrate the landfill and the
recharge and northern boundary condition as the flow inputs the
head at the northern end of the landfill drops about 5 feet from its
previous value A flow pattern from the north central part of the
landfill to the eastern side indicates a 12 feet head difference
with recharge - but with the upgradient stream a 16 foot head
difference occurs Considering the transmissivity change the
stream would increase the leacnate outflow from the landfill
approximately 43 under a low water table stream influent condition
to the aauifer This would increase leachate outflow to the east
side to approximately 129 gpm This value approximates the
56
outflow at the SE weir location during the summer monitoring period
when the upper stream was not flowing (Table 3) The outflow from
the western third of the landfill whicn lies to the west of the
ground-water divide would be approximately 63 gpm
Realizing the importance of infiltration to tne landfill as a
major influence on the generation of leachate an analysis of this
w i ll be discussed An estimate of infiltration was made using the
precipitation recora for October ana November (Appendix A) During
this time period a minimum of direct evaporation ana
evapotranspiration occured and the grouna is not yet frozen The
top cover over the lanafill is generally 05 ft to 2 ft of local
sandy soil and subsoil availability determined what was used The
top of the landfill is at an elevation of 92 ft as compared to the
ground surface at well W which is at an elevation of 76 ft
(Fig 25) This compares to the well W water level which is at an
elevation of approximately 52 ft This creates a long path for
infiltration through the unsaturated zone The topcover generally
slopes eastwara at a grade of 2-5 The west side maintains a
relatively steep slope of 10-15 ft drop within 50 ft ana the north
and eastern slopes have a more gentle slope of approximately 10 ft
within 100 ft distance An unlined surface arainage swale channels
surface runoff from the northern section of the landfill past the
NE well to the eastern side ana low area in the vicinity of the E
well This has a drainage swale to an area near the stream but
doesnt directly connect to tne stream A poorly graaed drainage
swale exists on the landfills left side The landfill material has
57
excavation
seepage observation ^
hole
Legend bullmdash landfill limit -^--excavation limit r^s- stream
copy WNWNEECSeSCSEN monitoring well locations
--- unimproved road O location of amp Inf i l t rometers O
feet
Fig 25 Infi ltrometer Locat ion and Drainage Feature
58
been placed in 10-12 ft cells and covered with 1 ft of soil at the
end of each day The material has settled differentially creating
areas for depression storage
An estimate of the percentage of precipitation that infiltrates
the landfill was made from precipitation records recorded well
elevations and an estimated specific yield for the landfill
material The volume of water that infiltrated should eaual tne
specific yield multiplied by the well water level rise Several
recharge periods were studied using this relationship Once the
percentage of precipitation that has infiltrated is determined the
percentage that is translated into runoff is simply the remaining
percentage if evaporation is neglected
From the literature for a slightly inclined slope of 2-5
typical runoff coefficients range from 10-20 in either sandy or
heavy soil (16) The landfill cover is generally sloping to the
east which creates a long path (approximately 400 ft) before the
runoff reaches the steeper slope on the eastern side of the landfill
of 15-20 The long drainage distance creates a greater time for
rainfall to infiltrate Another consideration is the actual
capacity of the soil to conauct water into the soil which was tested
in the field using double ring infiltrometers An average initial
percolation of 8 mmhr the first hour and a subseauent rate of b
mmhr occurred (Fig 26) The 8 mmhr rate compares well with
other sandy soil infiltration rates (14) Therefore if the
intensity of the rainfall exceeded a 5 mmhr rate for several hours
59
CO + 09 o
E o
CO
o Z pound C
O
C9
o DC
CO
CD CM
ogt CO N- to -4 CO CM
jq tuu i U O | raquo B J J | | J U |
60
on a poorly drained surface the additional rainfall would be
translated into runoff because the soils infiltration capacity had
been exceeded
The initial 8 mmhr infiltration rate was due to the pore spaces
in the sandy soil being filled and the subsequent 5 mmhr rate was
percolation into the low permeability landfill material The tests
were conducted in November assuming a minimal evapotranspiration
and the field capacity of the sandy soil had been maintainea
The W well was used as representative of the water elevation
changes in the landfill because it is directly adjacent to the
landfill 900 ft distant from the upgradient stream This minimizes
the effect of infiltration from the stream and maintains a high
contaminant level During periods of high runoff conditions excess
surface water ponded in a poorly graded drainage swale on the west
side and directly adjacent to the landfill This influenced the W
well at a time the contamination level dropped (Fig 11) Before
this occurence in mid-December the rise of the W well closely
matches that of the SC well and a background well SK6 which is
located outside the study area (Fig 7) Therefore it was analyzed
as a valia indication of the water level rise during the mid-October
to mid-December period The monitoring of the SC well was
intermittent due to inaccessaoility because of 10 ft extensions
being placed on the well as the refuse was being filled in arouna it
61
A high rainfall period from 14 November 1981 to 1 December 1981
was chosen for the initial study period The effects of
evapotranspiration were neglected due to the cool temperatures
experienced at this time Therefore it was assumed that the field
capacity haa been reachea and tnat any additional input to tne
unsaturated zone would result in direct percolation to tne saturated
zone During the time period 14 November 1981 to 22 November 1981
029 ft of rainfall fell and the well W rose from 488 ft to 493
ft - a 05 ft increase During the next 8 day period there was no
precipitation yet the W well continued to rise to 4972 - a 042 ft
increase The slow percolation of water through the landfill
material would account for the latent rise in the well water level
From previous reports a specific yield for refuse was estimated to
be 028 (1920) This value is dependent on the original compaction
of tne material age and resulting consolidation
During the 14 November 1981 to 1 December 1981 period 029 ft
of rain fell and the well increased 092 ft The following
relationship is used to evaluate the infiltration value and runoff
I = (Sy) h
Sy = specific yield
h = well rise
I = volume infiltrated
I = (028) (092 ft) = 0261 ft
62
The difference between the precipitation and the infiltration is
the runoff (assuming no evapotranspiration) Therefore 029 - 026 =
003 and furthermore 003029 - 13 runoff This corresponds in
the literature to a typical runoff coefficient for an inclined
surface of 2-5
Analyzing a longer precipitation period from 18 October 1981 to
1 December 1981 a net precipitation of 043 ft (accounts for
evaporation) occurred less 10 for runoff or 039 ft infiltrated
This results in a 139 ft elevation increase The well water level
actually increased 132 ft shy only a 5 deviation from the
calculated
From tnis investigation it is seen that a large proportion of
the precipitation has the potential to be transmitted into the
landfills saturated zone Exceptions are wnen heavy precipitation
periods exceed the soil percolation capacity frozen ground prevents
infiltration and direct evaporation and evapotranspiration recycles
the ponded surface water and infiltrated soil moisture back to the
atmosphere In retrospect water temperatures within the monitoring
wells could have been measured to indicate thermal effects from the
landfill on ground-water temperature Ground-water temperatures
were assumed to be 50deg F (9)
63
Specific conductance measurements serve as an indication of
contamination levels These measurements are used to trace leachate
movement which represents ground-water flow patterns Factors which
must be considered when monitoring pollutants are the attenuation of
the leachate contaminants which occurs both in the zone of aeration
and the saturated zone The former is a more complete process
Dilution dispersion and cation exchange are the primary factors
involved in decreasing leachate concentration in the saturated
zone The glacial outwash materials of southern Rhode Island do not
have a cation exchange capacity or a high buffering capacity so
attenuation is simply by dilution and dispersion (22)
The NW well consistently exhibits relatively low specific
conductance levels even though it is in landfill material It is
situated in a drainage swale and ground water elevations range from
543 to 5944 This is several feet below the upgradient stream
elevation of 64 feet which is less than 400 feet away The bottom
of the wellpoint is at an elevation of 5312 feet well into the
landfill material Infiltration from the stream to the landfill has
occurred at this location
The W well is situated on a bedrock high adjacent to the
landfill approximately 900 feet from the upgradient stream and its
water level is higher in elevation than the excavated pit (West
Observation Hole) which is 300 feet directly west The W well
maintains a contaminated level A poorly graded drainage swale to
the west of the landfill provides areas for extensive ponding and
infiltration to occur which explains the drop in conductance after
a high runoff period
64
The SC well is located in landfill material and has a
conductance of over 8000 umhos This indicates that leachate is
undiluted The oottom of the wellpoint is at an elevation of 389
feet which is situated in the landfill material
High specific conductance measurements in the west observation
hole and well W and their relative elevations indicate a
west-southwesterly flow direction from the landfill Infiltration
recharge and leakance from the stream into the landfill provides the
necessary elevation to cause outflow in this direction
Contamination from the landfill to the surrounding streams is
evident (Table 4) During the period 15 August 1981 to 27 Octooer
1981 there was no flow in the stream that Borders the northern and
eastern side of the landfill until a point just south of the E well
was reached High specific conductance levels in the EC and NE
wells were recorded (1000 jjmnos) At a point directly east of well
EC a pool of water existed that was relatively uncontaminated which
is designated as the East Stream] location (Fig 10) At a point
just south of that (East Stream^ polluted water in the streambed
was flowing at a low rate This was measured at the SE weir
location and which had a high conductance also Flowrates varied
between 6 and 23 gpm and specific conductances were over 350
pmhos This low water table condition flowrate is the baseflow from
the eastern side of the landfill and indicates a southeasterly flow
direction from it
Streamflow commenced in tne northern part of the stream 21
October 1931 and the north dam oegan to f i l l Stream specific
65
conductances were low indicating a clean water source Tnis
continued until 17 November 1981 when the dam overflowed ana flow
throughout the east stream began A weir was placed at the Rose
Hill Road NW location and was compared to flowrates at the SE
location Flowrates decreased and specific conductances increased
between these two locations
To further investigate the condition of a lower flowrate
downstream than upstream an intermediate weir was placed at the E
weir location (Fig 9) This snowed tnat the stream from the M
weir to the E weir was losing water to the aauifer (influent
condition) and gaining water at the SE weir (effluent condition)
The condition of a net loss of water between the NW and SE weirs
remained until 19 December 1981 when a snowmelt rain condition
caused increased surface runoff and a net increase in flow at the SE
location Upon analyzing the March and April 1982 streamflow
conditions the expected case of a net ground-water pickup from the
E to SE weir continued The explanation for tne initial net loss of
ground-water is the fact that the leakance from the upstream section
was being discharged into aauifer storage to raise the ground-water
table to an eduilibrium level Upon reaching a high recharge
equilibrium steady state condition any additional input will
eventually be transmitted as baseflow out of the landfill and a
downstream net pickup will occur A hign water table condition
prevailed during the January through May period maintaining this
condition In April the north dam broke through reducing the head
in that area by 4-6 feet The 9 April 1982 monitoring revealed that
66
an influent condition remained between the NW and E weirs but at a
reduced rate The 21 April lower stream flow condition shows a
small pickup of water between the NW and E weirs indicating the nigh
water table and low stream flow conaitions combined with the absence
of the dam had changed the conditions to an effluent condition
This was evident in the May monitoring period
Evidence of contamination on both the western and eastern sides
of the landfill supports the existence of a ground-water divide in
the landfill The west stream which drains the excavated area to
the west of Rose Hill Road shows contamination pickup between its
northern section and the SW weir The W well and ooservation hole
indicate high contamination levels which reinforces the concept of a
contaminant outflow to tne west excavation stream
As shown previously flow towara the eastern side of the
landfill is evident from the nign specific conductances and specific
conductances increases in the stream This is especially evident
during low flow conditions when the stream starts at a point to the
east of the landfill and flows with high specific conductance levels
From the literature a relationship between specific conductance
and dissolved solids exists the dissolved solids (mg1) are
approximately equal to the specific conductance times a factor
ranging between 55 and 09 (39) in this case it is taken as
065 (41) The dissolved solids increase coupled with the stream
flow increases provides a basis of calculating the dissolved solids
outflow to tne stream This calculation method was used in a
previous study (26)
67
The relationship
=Cinout Coutflow Qoutflow - Cupstream Qupstream Qinput
where the numerator is the streamflow pickup and the C- and
Q-jnput is the concentration and flow input from the ground-water
This can be used to estimate dilution level outflows from the
landfill Initially this is used for the ambient ground-water
pickup between the E weir and the SE weir This entire flow doesnt
come from tne lanafill but much of it is conaucted in the high
transmissivity area between the lanafill and stream from upstream
leaxage ana surficial recharge Tnis is evident when this section
of the flow pattern is analyzed on Fig 22 Therefore the landfill
outflow is mixed with tne ambient groundwater flow which dilutes the
landfill leachate before it enters the stream To illustrate-this
concept a calculation using the 9 December 1981 monitoring is used
At this time a flow of 672 gpm occurred at the SE weir with a
specific conductance increase of 7 ymhos between the E and SE
weirs The dissolved solids increase would be approximately 795
Today in tne stream
Where
Co = 90 jumho at SE weir
Qo = 672 gpm at SE weir
Cus = 83 jumho at E weir
Qus = 606 gpm at E weir
Qinput = 66 gpm gain
Cinput = 154 jumho
68
The 154 jumho value represents the contaminant level in the
ground-water adjacent to the landfill
This relationship is applied to approximate the concentration
level dilution in the ambient ground-water between the landfill and
stream The aforementioned relationsnip is in turn applied to the
landfill outflow into the ambient ground-water flow adjacent to the
landfill The ground-water receives landfill leachate dilutes it
and then transmits it to the stream The previously calculated
value of 129 gpm was used as the outflow from the landfill
Co 154 jumho flows into stream
Qo = 67 gpm flow into stream
Cus = 83 jumho background level
Qus = 67 gpm - 129 gpm = 541 gpm
Qinput = 129 gpm from landfill
Cinput = 451 jumhos
Approximately tne same contaminant levels from the landfill (tbl
umho) are arrived at as existed in the summer streamflow conditions
when the upgradient ground-water flow adjacent to the landfill was
at a minimum
In addition to using specific conductance to define
contamination zones electrical resistivity can be used to indicate
contaminated areas The measured earth resistivity is inversely
proportional to the conductivity of ground-water Water containing
contaminants with high ionic concentrations are more electrically
conductive and will have lower resistivity values than surrounding
natural ground water Therefore resistivity methods can be used to
69
delineate plumes of contaminated ground-water that have hign
specific conductances This has been demonstrated by several
investigations (11122328374045)
In this study a Schlumberger vertical electrical sounding R-l
was made in an area of known contamination at the W well (Fig 12)
Given the geologic constraints provided by the well boring log a 4
layer computer model was used to match field survey values A
Schlumberger sounding R-2 in an uncontaminated area north of the
landfill in the same geologic setting was used to provide a
comparison background sounding (Fig 12) A seismic survey N-4 was
made to obtain water table depth and depth to bedrock as input
parameters to a four layer resistivity model (Fig 8) Tne results
of the electrical soundings have been tabulated in Table 6 and
plotted in Fig 27 and 28 respectively
The ascending portion of the field Schlumberger curves were
initially matched using a two-layer ascending type master curve to
provide an approximate depth and apparent resistivity of the
overburdened topsoil layer (8) Tne second unsaturated layers
apparent resistivity was determined by using the graphical
interpretation of total transverse resistance The total transverse
resistance is approximately eoual to the peak value of the curve
times the corresponding Ab2 distance it occurred at This in turn
is eaual to the sum of the first two layers apparent resistivity
times their corresponding layer depths
70
bullH
OJ bull bullH 4J CO CM
c ce G bullrH
j-gt ca c c a 3 ltu O L
co CO 0
bullo Q bull laquos c n 3 -U OrH f~ 3 bO ltn y CO O cc CO ^mdashN
QQ bull
bO bOJJ C C Ci_i
O l T i O O O O O O O O O O O O O O O O bullH bullH mdash^ bullo 0 C c3 f| 3 O raquo O CO CQ
CO
rH
CO O
L 4J
^ltU
i- 1 ^n ^b O 4-) bull2 CM bullH C OJ 1 -U bullH CO C L O a ^-^ 0) a
rH c a L CD ltu (1) 3 tlt bO cO I
3 a 0) a Q 4J laquoa e CO 3 (H bO c C O bullH
CO TJ C 3 bull
bull O bO -i-3
0 CO C O3- O G O O O O O O O O O O O O O O O O O O ft rt1 -raquo - t l S^ ft tfigt f I mdash^ K_ l_ raquo mdash I gt fgt I l 1
(1) 0 rH CO CJ JD o^^ CO CO CQH lts
71
Legend
A actual field measurement
-e- interpretat ion
10000 bull
6000 bull 5000
4000-
3000shy
pound2000| ltD
_ r 1000
09
5 600 pound 500 - 400
I 300 a a lt 200
100 10
Fig 27
20 30 4050 100
Distance AB2
Schlumberger Sounding
200
feet
R-1
400 600
72
loooot
6000 5000 4000
3000+
laquo2000 e
r 1000
raquo 600 pound 600 ~ 400
$ 300 a a lt 200
100
Legend
A actual field measurement
-Qmdashinterpretation
10 20 30 40 50 100 200 400 600 Distance AB2 feet
Fig 28 Schlumberger Sounding R-2
73
Formula T = f
Background Sounding (9000)(15) = (3110j (1 7) + gt2(8)
= 16214 n- ft
W Wel l Sounding (b200)(60) = (500) (2) + pound2(28)
= 13250 SL- ft
To determine a resistivityp3 value for the third layer a
graphical interpretation for the longitudinal conductance S was
used(48) This is eaual to the sum of each individual layers depth
divided by their apparent resistivity
Formula S = -r1 +~r-raquobull-ra
Background Sounding 0017 = yyg + ~^
= IbOU - ft
W Well Sounding 0285 raquo -ggg 7^3 J~
= 179 v-ft
These values were input to a program which calculates a
schlumberger sounding curve (47) The theoretical sounding curves
approximately match the field curve as viewed on fig 27 and fig
28 To provide a check on the apparent resistivity of the saturated
layer at the W well the following relationship was applied 1OOOO
= spec-jfic conductance (umhos)
74
At the W well the specific conductance was measured to be 3 00
jmhos at approximately 10degC
Assuming a formation factor of 45 for the glacial outwash (23)
material Archies law is applied to estimate an apparent resistivity
of the third layer (7)
fgt FF x p
A= 45 x 103-n-ft
A= 4G3 JL-ft
This is a reasonable approximation to tne 3i= 179^-ft calculated
analytically from the sounding curve interpretation
75
Remedial Measures
With the analysis of f low patterns and contamination zones
recommendations to minimize the environmental impact of the leachate
can be reviewed The basic technique is to minimize all sources of
water reaching the refuse so that leacnate production is minimized
The oiversion of precipitation by a relatively impermeable cover and
proper channeling of runoff would minimize percolation into landfill
material Caps and seals can be constructed of clays fly ash
soils soil-cement lime stabilized soil memorane liners
bituminous concrete and asphalttar materials (15) Proper
contouring and grading will help minimize infiltration If a soil
cover is used a vegetative cover can be planted which will utilize
some of the infiltrating flow through evapotranspiration losses
during the growing season By minimizing the length of slopes and
providing proper drainage channels tne surface runoff can be
conveyed to a downgradient area outside the recharge zone
Therefore this surface water will not increase leachate production
from the landfill Also by increasing the slope of the cover over
the landfill itself a higher percentage of runoff and lower
infiltration will occur
To minimize upgradient ground-water influx to the landfill an
impermeable subsurface barrier or intercepting trench could be
used Barriers can be made of bentonite slurry-trench cutoff walls
grout curtains or sheet piling cutoff wal ls extending to the bedrocic
or an impervious layer to effectively prevent water passage or
create a head loss that wil l lower the water table In addition an
76
intercepting trench which has a perforated drain at tne lowest part
of the water seepage zone could be used to intercept and divert the
entire flow
These possibilities have been evaluated with the help of the
model to determine workable solutions for this landfill The
primary concern is to eliminate leachate flows to domestic wells
Initially a simulation was run that eliminated recharge over tne
landfill area (Fig 29) This had a considerable effect on the
ground-water flow patterns of the landfill area The mounding that
had previously occurred under normal recharge conditions was
eliminated and a general drop in the water taole within the landfill
of 2-3 ft occurred The effect of eliminating recnarge over the
landfill when the upper stream is running would cause greater
infiltration from the stream as evidenced by only a 2 ft head loss
in the landfills flow conditions This is evident when comparing
Fig 29 with Fig 24 Tnis indicates that this measure would only
marginally reduce the resultant leachate flow from the landfill
material that lies below the water table In another situation
where there is not such a strong potential for upgradient flow this
measure has proven quite effective (6) In this case the landfill
cover consisted of four layers an intermediate sand and gravel
cover immediately above tne regraded waste materials a 4 inch sana
bed designed to protect the overlying membrane a ilO mil flexible
PVC membrane and an 18 inch final cover of sand and gravel
77
Legend
landfill limit -raquo- -^ -raquobull excava t ion x-^x- s t ream
400 copy WNWNEECSESC monitoring well locations
= -= unimproved road fee t
Fig 29 No Recharge over Landfill
78
Controls such as 10-30 mil polyvinyl chloride covers favor the
development of an anaerobic environment which increases waste
decomposition time and would necessitate installation of gas vents
at several locations on the landfill cover Tne integrity of tne
synthetic cap may be further threatened by subsidence which create
differential stresses on liners Settlement would create areas for
ponding and depression storage and eventually necessitate regrading
the landfill surface The landfills south-central area has oeen
filled within the last year and will prooably need to be regraded
due to settlement within the next few years
Another possibility for a liner would be a soil-bentonite
cover A layered cover consisting of natural materials with low
permeabilities such as bentonite clay followed by a layer of highly
permeable material such as sand and finally a layer of topsoil can
be used Due to potential drying out and cracking of the clay liner
a synthetic liner is the preferred method
The most immediate technique is to grade contour and vegetate
the landfill cover which has been done at this site Althougn an
impermeable cover would probaoly reduce the amount of leachate
produced it would not eliminate the upgradient flow and provide
guaranteed protection of wells in the vicinity of the landfills
northwestern section
A slurry trench along the northwestern perimeter of the landfill
would effectively cutoff upgradient infiltration and divert recharge
infiltration in a southeasterly direction thus removing possible
leachate outflows from the radius of influence of the neighooring
79
wells This has been simulated using the computer moael ana flow
patterns as shown in Fig 30 Contour lines are distorted in the
vicinity of the slurry trench due to the 200 ft nodal spacing
Transmissivity values of 1 ftday were input at the slurry
locations to simulate an impermeable barrier Tne surface recharge
at those nodes does not infiltrate the relatively impermeable grid
nodes at the slurry locations and flows to the edge of the noae
thus creating a dramatic head loss within a short spacing To
effectively simulate this a variable grid spacing should be used
with reduced node grid spacing at trench locations to eliminate
distortion The computer simulation shows that the slurry trench
could direct flow in the landfill area in a southeasterly direction
and away from endangered wells In addition it would reduce
upgradient infiltration from the stream into the landfill This
measure would prevent leachate from spreading beyond this carrier to
possibly contaminate neighboring wells
The combination of both the slurry wall and impermeable cover
would be ideal measures to minimize generation of leachate and to
stop its spread to neighboring wells The slurry wall without
recharge over it or the landfill is simulated in Fig 31 This
indicates a lower water table tnan eliminating the recharge to the
landfill The slurry wall has blocked upgradient ground-water flow
at its location to the landfill
80
Legend
landfill limit -laquo- j -laquobull excava t ion ^^- stream
copy WNWNEECSESC monitoring well locations
= = = unimproved road ssi slurry wall
f e e t
Fig 30 Slurry Wall
81
Legend
landfill limit j- j- J- excavat ion x-v^gt- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road s==s slurry wall
400
feet
Fig 31 Slurry Wall without Recharge Over It or Landfill
82
An intercepting drainage trench is considered next If a trench
was excavated to a 30 ft depth in the outwash material extensive
shoring would be required In addition difficulties would arise
when the trench was excavated below the waterline Tne trench would
be sloped to provide drainage and backfilled with a highly pervious
material to intercept and divert leacnate locally a conouit which
is perforated on the top to allow infiltration and unperforated on
its lower perimeter to permit continuous drainage to the collection
treatment center would be installed on the bottom of the graded
trench The difficulties involved in excavating below the water
table ano shoring the sidewalls to permit implacement of a drainage
conduit at a 30 foot depth make this option increasingly infeasible
83
Conclusions and Recommendations
The location of the South Kingstown landfill in permeable sand
and gravel glacial outwash material (107 ftday) combined with the
high hydraulic gradient across the landfill area (20 ft1600 ft)
creates a high potential for ground-water contamination to occur
This is intensified because refuse nas been placed below the water
table The low hydraulic conductivity of the compacted refuse (1
ftday) and the excavated area to the west of Rose Hill Road have
both contributed to modifying the original southeasterly flow
pattern These modifications have created a ground-water divide in
the landfill at approximately the western third section Tnis
results in approximately 13 of the leachate flow from the landfill
or 63 gpm flowing in a southwesterly direction and 23 or 129
gpm flows in a southeasterly direction Infiltration from
precipitation recnarge over the landfill (up to 9Upound) and from tne
upgradient stream during low water-table periods provides tne
necessary influx into the landfill Evidence of contamination is
clearly seen on both the east and west sides of the landfill which
reinforces the previously stated flow patterns
Of the several remedial measures reviewed the contouring and
grading of the landfill topcover and drainage swale provides the
most immediate protection The topcover has been graded mulched
and seeded to provide a low runoff slope generally to the east
The drainage swale on the left side of the landfill has improperly
graded sections which should be corrected Its northern section
could be drained into the northern sections swale and the southern
84
section drained to the southeastern section of the landfill Tne
point of the drainage swale which divides the northern drainage
swale from the southern one should be determined by a field survey
Cost is a major contributing factor when determining which
remedial measure is to be applied to the given situation For the
purpose of this report cost estimates are not presented but rather
the effectiveness and feasibility of the remedial measures are tne
primary considerations As was reviewed and simulated in the
computer models the slurry trench and impermeable cover over the
landfill are two viable options that would effectively provide
protection to the domestic supply wells in tne vicinity The
impermeable cover would eliminate precipitation recharge into tne
landfill yet drop the water table only a few feet due to upgradient
infiltration from the stream This would decrease the hydraulic
gradient thus diminishing the potential for a contaminant outflow to
surrounding wells The supply well of primary concern is one to the
west of Rose Hi l l Road marked well D on Fig 2 If contamination
occurs in this well the most effective measure would be to block
off leachate flow in this direction by installing a bentonite slurry
trench at the location indicated previously This would effectively
prevent leachate flow in the westerly direction and diverts it to a
more southeasterly direction In addition the slurry trench
precludes infiltration flow into the landfill from the upgradient
stream
85
Tnis report has effectively reviewed tne original ana existing
flow conditions and contaminant levels in the vicinity of the Rose
Hill landfill The purpose was to provide an understanding of
ground-water contamination patterns and study possiole remedial
measures
86lt
Appendix A
Precipitation Records
Monthly normal precipitation 1941 -197O
i$l Total monthly precipitation
KINGSTON RI
14
ia
^JO T I bullbullL
pound 111 laquobull
4
a
n
-
^
-
-
KS1JAN
^Ii R3 HB MAR
1
1 APR MAY
1
1 JUN
1981
JUL
-bullraquolaquo H
AUO SEP
K3~~f$s bull
_imdash
i1S 1
OCf NOV OtC
171 1 iI1
JAN HB MAR APR MAY
198
Fig 32 Precipitation Record
- - - -
IM 1 MtvJrflgtlgt c ortli-A t lUN I r nraquo rl - -
gt|MO CLIMATOLOQICAL OUSERV ATIONshyr-r bull JK gt raquo - 1
i5fWA I VAPOR Al IOH -bull AIM If MPCRATUM bullF 0 riccipn AT ION UNO IlMf
bull 14 H 14 H mdash Vshy ADDITIONAL DATA IfUAlUS OATt 1 bull raquof bull bull 1 ta
14 Hw rlaquo4 w bullbull bull 1 114 1mdash4 (llrl 1 1 1fl Hll
0 kmdash
Mraquo M4 raquo i T i 4 bullraquo-laquobull i i
Lgt f 1 21 S 1 Hbull - - bullbull -
ltJL 1 2 01 - - _ _ 1
mdash
-
1 12 _ Q I
mdash shy
mdash 4 (C ( - - fVi 1 - 0
1 (1
^ 1
Vvraquolaquo IJ1^ raquo CP O 3L 1 Z - i bull j-t-J
1 J
LH Vb T n 0
1 gt fl oo O ~l 2 L - bull 1 P )laquo jn iP IP - OOI L5L mdash shy
-t 84 ^(^^ ^fi P i flja 0 JO II 10 tl tcgt 7 J IV wllaquo
h l2L bull 0 lt -_ shy
-id VJ lt 3C 2 ft OOL -mdash
U 71 C1 Sr 2 13 2 nl JLJraquopound HP r M ltf1- (
IMe 2 ii O It
n jlt dl 1 1 bull o o-il ST i 1 i 25 2-x-1
-
ri
i tlL O mdash gtbull bullgtlt 1ft -o- is Oil So iJK 2-io otv u 31 fil loi 2 il Oll it Of wr is i1raquo -iZ 1 deg|0 01
M IT So - mdash
- 13 1 CT mdash i - mdash 21
shy
Tl Ci av ZUll IMT 0 IM Pe v _ 1) T) S) ii3( dlt Ii 2 lt^2 II li- S1 riivi To 7HX lt3lO 14 ^2- iTi I li 011 -- - -i -^IS no 5^ or i | T Jift laquoV OoH bullla It Va iCO mdash L OIL 11 bullvf poundgtpound lS_ flv oh P-lfe 1 poif _ shy11 IB kl (4 itlaquoT lamp llt0 oot^
mdash -n
It T1 |ir( L1 HI 2 0 oil
U 1M ft go C ICf^ -^2 Z laquo-|o
11 it 5 bulln - TO o abull Li u-i IT1 -- Iw O ltM (I bullbull bdquo-I(K 1mdash -tilltLlA ttfe
i Dgt ac -- U 44 4 11 1 1- ytd i i_i J-K 0 i if -i i i V t Wl raquoOHM 1-1 US D C P A R T M f N T OF COMMfRCE t 4 1 IUII 1 1 ^~) mdash
llaquo- Hi NC bull bullh bull bullJL^V HBl CO 00
11
)jLsVyr^gturv
^ | TKu
|-_t_ bull(
IIMgt I I Mt|UU III- II 11
PNECIPITATIOH
I 1 1 IMX
IMO
bull llfclaquo I UCIUKI) Ur C V A r U M A AHO CLIMATOUOCICAL OBitH
E V A F O R A T I C r i Jttffl laquo amp hMIlaquoJllaquoJIIlaquoBgt
DATE AOOITIOMAL DAIAKMAKk M
bullraquobullmdashlaquo
tp 01 (1 Of Ll OOI ooo
0^1 o-i 10 tl |00 102
OC (1 13 Ofl
it i rc DS os an
(1 SV o
Ul 010
(ISl 101 I on
130
II 5= Otl
ss lt 001 (IK Ml
jt il HIT
7 it
ow Wo 17 Top 2-01 OIO
(0 oov zi oot
u CO ^A 0 to Zoi CLflS
bull50 01 ljtj
nshy 5H LO OIt
50121 IVO QJO
14 Co Ho LO Hl ^pound Jl 1
ltM ool fllc
H Tl 01 II
11 11 Q1
iH OIO
HO 2 llaquol 11 II
lifc
IV-IIM ul OIPAITHINT or COHMIICC NOAA
NAtlOHAL gtIATnlaquoll raquotraquoVlClaquo CD
r~
All TCUMMATUNI ^V UII rgt ITmi 1 Cwphu Obic i gtn t ngir-H 30
rilCiriTATIOH
JJ T I rTJ-rimdashr-iramj|MP CLmATOLOQ
laquolaquo jftilCiii bullIHO
Oi1l ADOITIOHAL DAIAlllu
Ilf4ft
Sii1
(1 2 IO OO
Hl ii SO
us OIM
Q^L
a A3 Hi SZ Sf^ bull 12J2
HI Z-SF OOl 1C t HM IA H ICP fiJA
OOl 10 (310 sn 310
if HI (0 ^01
bullit SO 28H poundJ1 11 006
14 35 TX oon II (bull2 it zr II c-S
rr Zll lo 31 OP an 31 a 31 oor
CSW O-ll Si CC Of 011
Oll _ I |ft
00
u i oerraquolaquoTMiMr of c NOAA
NATIONAL K C A T N C M SCMVlCC
TC^S lk)oiVroTJA
TETT I 7X
1raquolaquolaquo 4 bdquo ir lt er ni I^OV ltqgl j--^ TQ
MICiriTAllOH ITIND
D|mdash
b5NO ctiUATOtoiCAL oeit^
OATI AOOITIOMAL OATAVlHAtt
0-tt
Mlaquoh bullbullbull- rshy laquo
I- ltltriu HI I 4 bulllaquobullbull1
Zii
30 Dfellt otvt
at HA
OOI
62
iJ_S2 HI if
bull- 20 SI 2i So
So
VVfr
OSfc
I (
Jtlt
3aoi
r j -bull ie MA
Irill iiol
in^ 14
Mo
Zll
214
21 1P
00-i
bulliron
17
bullr
11 i ir- I J Ktf^c
US D E P A R T M E N T OF COuMEDCC I | C gt A A
K AIlaquo Ttupf lATuit r
|SlVi AlJ PIICIPITATION
oJud (El
VIM i Uraquo
MIND E
EVAPORATIOH flnrft bull A ftufiifccdll
KECORO OF eVAPllHAtlil bull I CLIHATOLOOCAL OBSERVA ^Hij
14 MM A_M AOOIIIONAL DATA11 MAIM
Mr bullH Oo|
M Si lift
bull221 IHI
ZS Ji 40 IZV
icr KS I
HZ 111
bullT 21
loA UK JA IP
v^ ft
1M 2Sshy IT Tl
71 V |
i I 31 1deg a
uty^ U bull3
ons 1 CiO TxX
HHO (10
3H 19 12 10 IP
raquo3H raquo | 5t io
OP OIT
14
vO UI Of PANTMINI Or COMMCRCf MM O A A
F ngt TIHH
iiicffwiffc 4 rJ (TIM bull Cempltit Obitittiio
AIlaquo TIMHIATUM PHICinTATION I V A f OK ATlPrl
OATI ADDITIONAL DATA KMAlIt
U4laquo4 +
03H Ji
10
rc a 1 16 oi ii
tiiy 10
OI
II i23 or o 13 -y~ou HO
II 3V III i 3 t
V laquop oot
OM1 SS ne
T an -i IP
Olt zr LTV
3T 001
a -11 2T
10 an 31
-1 raquo 131 UP 3H lf 14 Lpoundshy
it 14 30
IS
Ui O I P A K T M f H T OP COWlf ICfM O A A
NATJONAI V C A T M C n f t K M V l C K
bullbullbullbullbullshy -2 o AIlaquo TIMMRATUM f fKICIPITATIOH
OATI poundt- MMINMAL DATAk
ZP 51 lo icr
011 111
OoT IHf
Ut 003 am
3o 13 ao
4A X 05shy
H4 i IjJyiV131 ooc js
IH oi 01 tL 18 13 a
No 11-7
rivgtp OO| M Hi 03 01
It 12
bull I 41 bull7119 14 ^^ raquo 31 15 lampk n M ho i
Jo -j-
-J
I
Ml H^ I _
amp2ampUi^= LS 0 S 0-f bullTTT
-Vmdash gt U_ bull 1 rOHM I- 11 OI OCPARTMlNT OF COMM(NCC
HO NATIONAL W f A T M f H ftfraquoVlCI
98
Appendix B
Boring Logs
99
X iHECT 1 ff 2
OAT American Drilling amp Bor ini I Co Inc
wo WATH smn EAST PR ov IDENC E ft 1 Town of South Kingstown South K ngstown R I MOLENO X-J
TC 100 RCSS bull ujrMonitorinq Well Installation | South Kinqjtown R I UNC a STA Pf KXICCTHJ LOC ATK3N
bull cfrserrr TO above S MPLES S FNTTO _ _ |laquolaquor A-109 SURF ELEV RE PORTSEr
GROUND WATER O6SE RVATC MS 1 CDREraquolaquo m-T nn75 laquo A 256 - 20 mdash Hew y
Instolled 32ofT-l2 PV C - JO- COMPUTE 111275 K toia 3- I-WI 1-38 TOTAL MRS bdquo10 screen BORING FCACUAM J K lanq MAI rraquo HomnwWI 300 140 IampPCCrc Mamlaquor Fall 24 30 lampaaiona SOLS ENGR
LOCATION OF BORING H ONITOKING WELL
Coung Samplt Tjp Blow per 6 Manure SOU IDENTIFICATION Strata SAMPLE ^^^yV Bloot
foot
Otptni
From- To
el
l
on Sampler
0-6 1 -6-13 12-18
Dentity or
Conmt j
Chang Remark include colo^ graaation Type of tod lie Rao-coMr type condition nordshynetiDntotf time leamt and tie No Pen Rtlt
2 No top sample 5 12
1 loamy fine sand
bull)^ 40 30 36
5- 616 0 23 20 16
noist iense
Brown fine to coarse SAND some fine to coarse gravel Trace silt
^
1 18 18
36 8-0shy57 40 30 V 35
|0-||-6 D 14 24 20 Srown medium to coarse SAND Some fine gravel cobbles
7 IRshy 16
27 75 37 3
IS- I- D 5 14 16 3bull
ISshy 15
42 50 I9--0shy50 65 20-2ll-6 D 9 23 26 bull Jrown fine to coarse SAND Tbullwshy 1Z 75 90
22-0 Trace silt trace fine gravel
124 120 74 60 52 41
7S-ltlaquoil-A DX 71 16 13 wet very dense
Gray-brown fine to coarse SANC Some fine to coarse gravel little silt
H IR u
40 30--0
3C-30-IO
3l4-334
334-3314
38 4-434
D
c
C
C
7 IflO
94 6
we tr j
y se
ft irox
30MOshy
31 -4shy
Gray-brown fine to coarse SAND Trace silt
Gray-brown fine SAND some lilt trace fine gravel
Too of Rock 31 -4shy
Gray-pink GRANITE
6 7
amp
CJ
IltJ A
60
601
IQ mdash
2(
4
5 i Hard
ft 5ome seams bull
GROUND SURFACE TO J 4 U3CD_ ^JVrf bullbull( tutu t to 4o 4 SampM Type Proportion UMd MOB Wtx 3 OfaM on 2OD Sampler SUMMARY-
OOry CCartd WltWen4 Hoc OlolO Canmonieraquoi Don any CoKeem CarMWncy Earm Barrlaquoj 11 14
UPgtUnOigtturod Piuon trite (Oto20dego 0-Kgt Loei it 0-4 Sait 3O+Hofd Rock Corng 14 Kgt-30 laquo4 0 rte 4-8 MSHM Samplet TPTtitPit Ai Auger Vvanefett tarn 2Olo39 3O-M Owlt n laquo-lS Strlf rinit nn v 1
UTiUndlshffbed ThrMOll and bull 33to9O 5O Very 0laquo nraquoe 19-30 V-3trraquof - | OLE NO X-l
TOVH rim - iA it raquotoraquo
100
SHEET 2 o_L
WO WATEt STUET [AST ft OVIDENC pound a i American Drilling amp Bor ing Co Inc
MCLl WQ X- 1 Tt AOORCSS i
LIME A STA KXICCTMJ tuf same as 1 | tame as i LOCATION
W PORTSEf mo OB nj urt eflaquo T
illtPLES S
P
CVTTO nlaquo mun orv
^s f^ Tin i GRCVMO WATER OBSERVATONS CASING SAMPLER CORE BAR
START Typi COMPUTE tome at 1 same aiH
TOTAL MRS BORIMG FOR CMAN n bull IT INSPECTOR SOILS EMM
LOCATION OF BORING u HfVJTneTfi UFI _
8
Counf Blo-t
foot
Dtpllo
From To
0( on SampMr
0-6 f 6-IZ
Moittir
Oonuty or
Contilt
Strata Ctnngc
SOIL OCNTiriCATION Rtmorkt ineHifl cotot grqdotion Typlaquo of Mil etc Roo-axtrPlaquo condition Mrdshynlaquot Drog tun ttomt end tic
SAMPLE
No Ptfl RfK
434-4o4 c
approx 7 minj
per toot 454
Gray pink GRANITE Hard Fairly solid core
lt_4 24
Bottom of Boring 45 -4
-
~
bull 1
GROUND Sorrow Tye
SURHCZ 10
bull OiOry CgtCord WWothod UPUnditiurMd Piston TPlaquoTtraquotPtt AtAuotr VVor
UTltUndinrvd TTMMO bull bulltat
iivnPilaquo(onioni Uraquot4
me OioiOItttt laquoraquo20
wmt Z0ie33
and 361090
c M
C1 5 Si
-SOshy
ASING
IOtgtWtigt bullnlot Dn 10 Loci M Mod 04 SO Dm 1shy Viry 0laquo
s _
TMEN 0 hMl on 200 SoiTBUr laquoity ConcMMt Conorawncy gtbull 0-4 Sort 30shym 4-B MStlfl M BH9 Strtf bull ts-so v-swt bull
t-HOrt Ear Bern RoetCorrt
i ^^^^^ bull
-[MOLE no x-i
101
raquoMEC rAmerican Drilling amp Bor in g Co Inc 1 ofj_ DATE wo WATlaquo smn UST Plaquo IOIDCNC j laquo i
Town of South Kingstown South Kingstown 8 MOLE MO Jlt Z TC rx MCS3
rtprr uAurMonitorina Well Initollation | South KinqitowrxRI UNC A STA P KATIOM ME POCT ^rwT TO above I OFFSZT
uD^r laquorlaquorTTO 6 -109 suw tLEv Sgt louffJOCNO
0 tj Tlmlaquo WOUND WATER 06SCRVATC US gtW Rsdl SING SAM^EH CORE BAH
26 ^_ 12 $TAlaquoT UL 2Z2i Ji r TTP NW ltA sr IJZC Z5 CCOMPLETE
SitLO 3 I-3B- 1-38 TOTAL MAS 41 BOAINO FOACMAN JK1 ana nf ni n MonwwWl 300^ 140 BIT bullK^CT
gttonvrar Foil J^laquo 30mdash Diamond SOOJIEMGM
IE HFII
iCaunq SampM Trplaquo BMMtpw6 UOIIIK- SOIL DCMTIFKATION Siraia SAUPLE Blow DlaquoPIAraquo of on SompMr HtmorU mcJuo cotes gradation Type of Dwuily
pw or CXang writK Roel-eolorlyp condition tvort-From- To Vfoot 0-6 f 6-2 12-18 Coniitt egt rwtiOnAngtimt wamaondtte No Praquon Rtlt
2 Brown fine SAND little silt 2 2-0shy5 15 18 moist Browi fin to coarse SAND 18 5- 6-6 0 14 25 27 vlaquo Troc fin aravel | 25 wy Ifl 11
dlt tns 35 40 38 moist n in-il-i Lgt U 15 18 ie is li1 Irl IS 31 I2-0
~~43 1
A) Jrown coars to medium SAI MD 48 moist Little fine to coarse gravel
|5-IA-Xlaquo 14 47 41 fn D laquo y Little silt rrqa coarse sane 3 18 I1
68 In IS 44 32 34
n ^n-^i-A- w 2o 19 29 wet 4 la -59 lens ltfO no
25-0 2amp bulllaquo- 77 c BOULDER r[ 4 i
27-0 5X ~W 24 24 bullWar- 5 Ifl irown tine to coarse SAND some
dens 29-0- Fine-coars gravel trace silt
30-3I oxx 30 32 30 moist irown -gray fine SANDiom e 6 l rr Vlaquoy 31 -0 silt trace fine oroveTILL
Bottom of Boring 31 -ampbull shyBent casing -pulled out and moved over 4 - washed amp tJrovlaquo casing to 30 -Installed 3C gtof 1-12- PVC - 10 screen
WOUND SUraquoraquofCE TO 3pound 1 yijfD MW t ASIMC TMCJ laquo olaquorod -bor of borina
SomoU T]Fplaquo ProigtuliOraquoH UMd MIOtgtWLx3Orolt lon2OASanlaquoMr SUUMARY-D=Dry CCorad Wlaquoworaquonraquod bullact OiaiO CanM gnMM Daonty CIMIH Caamraquoci EffW 8or^ 2pt
UPiUnairurMd Pition Itnt laquoM2O O- O UKraquolaquo 0-4 Soft 3O-hHard Roelaquo Corrig o- JO M0mlaquo 4-8 MSNff SOTipM 1 p^ 3O-9O OwgtM bull-IS Slid
TPlaquoTraquojraquoPit AAugtr ViVon mini tamt 20to39 UTtundiifir6d TrwMOtf and JSloSO 50-raquobull Vary 0nlaquo [HOLE NO x-2 B-3O V-3Mf lev rim - IAIT raquosectlaquoraquo
102
300 iu 24
1 UMnii ffi 140 laquo 30
CA1INC tf
gt taWCTf
bull 0gtlaquo i R Cook Jr_ R Millineton1 Wttn
I~
1 VAMtl CtMG
1 W HO-t MO
1 Oraquo 1 laquo0~ twt
L 1 laquo-raquo VfcM^lf [wlaquoraquoCI ^ ^ K3Ot III laquo
0-LS D
5-65 D
LlQ 10-115 D
15-16 Tgt
Lraquo 70-51 n
25-26 D
F
I O-O Ci
A Allstate Drill ins Co vi o i
PROVIDING R 1bull raquoraquo uvraquonn~ N M O M I T O P I N G HE1 _^lt -^ PI-Traquo UJU
CUM Town of South Kineraquotown raquoraquo 1 1TA maoer Propolaquolaquod Sit for Slude Disposal nltn
laquo V-449 iampAAtut i a 138 ort STI bull r 42777 CtOuMO IKVtllON
Cill bdquo 258 DA II MN ru 42777 rilaquolaquodO laquoraquoTti rum 1911
AU1TATI
MMUI1 raquolaquogtlaquolaquo laquoKiO itXHHKraquoriOi of sous MUAHI nMTKlion Ot CMlaquoMC|kOraquort tl CO~VH DXltgt raquomlaquo laquotf IMi COIOI C4l II I 1raquo gtlaquo^ Oraquo 1Ol rC t Xgttgt VtfKOe Craquo Mi 1 ft liMraquoK laquo0^tlaquot nfgt
1-2-1 10 TOP SOIL FINE LIGHT BROWN SAND traclaquo of ilt
16-31-17
22-24-21 100 FINE TO MEDIUM LIGHT GRAY SAND trace of fine gravlaquol and raquopoundLt
lfl-37-34 150 LIGHT BROWN FINE TO MEDIUM SAND little poundinlaquo gravel
21-17-15 200 MEDIUM TO COARSE SAND bullomc fine gravel
12-4-10
265
Observation well installed
NOTE No casing blows taktn
bullbull B-23 ow
^w^ 265 I raquo bull raquolaquo bull I W
11 laquot gtbullraquo Vlaquo 14 W gt_ c-shyji bull alaquo bull jraquo VI laquoHshyw bullbull m raquobullbull D-6 raquo Mshy
bull bull laquo Vshy
1
bull bull
I
103
MAMMII Allstate Drilling Co ulaquorr 1 or 1 FftOVIOCKZ H L traquolS mTArm^S MONITOR NR WEL
VNO wr3JJO__raquoraquou_24__ HCU MO P-74 n iu riBwi Town of Slt7H^ Xirpin
mdash^ laquo0J P 1 1 bull ^n^ciit^o TVlaquow^laquott1 bullraquoit wt 140 nu 30 olaquor fBu lkv Waste Disposal Arcai
MUTAH a V-449 R Cook Jr UMlaquoiigti D 1 38 0t| raquoIJ raquo 5277 rlaquo SUMO luvlaquorv-laquow
mdash 5277 fipe -raquoT pfpm 150
H MCIO IMNTlXAflON Of SOU t(kAIlaquoS rrn 0-laquoraquo
5 -SF 01 w in laquobull -raquo ^ lit
D 1-2-2 TOP SOIL V-1-oraquo
15 IPbull FINE TO MEDIUM LIGHT GRAY SAND AND GRAVEL
5-65 D 37-27-35 some silt
10-11 D 20-14-18
15-165 D i 17-14-14 155
BROWN COARSE TO MEDIUM SAND little fine to coarse gravel trace of silt
20-211 D 4-4-2
230 GRAY BROWN VERY FINE SAND
25-26J D 7-8-9 AND SILT 265 fvarvedl
Observation well installed
NOTE No casing blows taken
wta 10 n uuraquo c^imdashbull IgtM laquolaquobull- B-24 ow ~ 14 ltfc laquoraquobull vlaquo^ M laquobull r O 0 fmtt bull W-L 26 5
-0- CgtCmdashgt bull laquolaquobull mdash laquo 1 - raquoraquo 1 gt 1laquo bull 1 gtraquor to bull mdashbull bull bull bulllaquo I t l~laquo 1lt Uraquo mdashbull ) bull 1 gtbull ft 0~ H laquoy bullM ta bull -IN la laquobull OPUM bull($ IMI
mdash H raquo laquo-bull
104
Appendix C
Calibration of Specific Conductance Meters
105
Specific conductance measurements were made using a beckman RB
338 temperature compensating meter and a YSI rtooel 33 salinity
conductivity temperature meter The YSI meter is not
temperature correcting A formula to compensate for temperature
differences to standardize YSI measurements was used (21)
A long probe for the Beckman meter was used to measure conductivity
in the wells Differences in conductivity between the YSI ana
Beckman meters and the Beckman short and long probes exist These
were calibrated in the laboratory using 001 N and 01 N KC1
solutions Values presented are Beckman short probe values The
Beckman long probe values were reduced by 76 and tne YSI values
were multiplied by 11 to adjust to Beckman short probe values The
YSI meter was used in the latter phases of the study for the
stream contamination due to the greater accuracy of the dial readout
scale
Table 7 Specific Conductance Meter Calibration Table
Concentration (KCL) 0001N 001N
Specific Beckman short 145 143 143 1247 1245 12GO
Conductances Beckman long 190 191 188 1639 1650 1665
umhocm 9 25 C YSI 132 131 128 1131 1140 1150
average values Beckman shortBeckman long = 075
Beckman shortYSI = 11
106
Appendix D
Computer program Flow Chart
107
F1g 33 Computer Program Flow Chart-
1TpoundR MAP TCO
NEWPER
WEWSTP CZAX
HEWIT TRANS TCOF ROW COLUMN
Yes
Yes
108 The following is a description of the USGS two-dimensional computer
program Iterative Digital Model for Aquifer Evaluation updated
December 1972 by P C Trescott The program written in Fortran
consists of a MAIN program and six subprograms or subroutines which
themselves are organized into subprogram sections The subroutines and
their sections are listed below
MAIN Program
DATAIN (subroutine) COEF ITER (section) CLAY MAP TRANS NEWPER TCOF
ETRATE COMPUT STORAG
NEWSTP LEAKAG NEWIT1 NEWITO CHECK ROW CWRITE COLUMN STEADY PRNTA OUTPUT DRY BLOCK DATA
The program begins in the MAIN program which controls the sequence
of passage to the subroutines Sequential steps are described in the
program as shown in the flow chart of Fig 32 Emphasis is placed on the
steady state confined aquifer case as applied in this study First data
input is read in the DATAIN subroutine This data includes transmissivities
or permeabilities starting heads storage coefficients and grid spacings
Nodal transmissivity values are then computed for the water-table problem
in the TRANS section (COEF subroutine) This procedure is necessary here
because the subsequent routine for computing iteration parameters (ITER)
keys on nodal transmissivity values which would not have been input to
the water-table problem In the water-table option these would have been
109
computed from given bedrock and water-table elevations to obtain the
saturated thickness component of the transmissivity calculation In this
study water-table option was not used and the transmissivity values were
input directly The program then passes to the ITER section (DATAIN
subroutine) to compute the iteration parameters which expediate or even
cause convergence Next the MAP section (DATAIN subroutine) is utilized
to initialize data for an alphanumeric map if this was requested in the
input options Transmissivities are then computed for the confined
(artesian) aquifer case (water table not specified with input options)
in the TCOF section (COEF subroutine) These coefficients are harmonic
mean values of adjacent nodal transmissivities weighted by grid sizes
Time parameters and pumping data for a new pumping period are then read
in the NEWPER section (DATAIN subroutine) followed by entry into the
NEWSTP section (COMPUT subroutine) which calculates the size of the
time step Leakage coefficients (hydraulic conductivity of the confining
bed divided by confining bed thickness) are next computed in the CLAY
section (COEF subroutine) if leakage was specified in the input data
which was used in this study
A new iteration is then initiated in sections NEWITO (COMPUT
subroutine) NEWITO saves the current head values and compares them to
the updated head values for determining closure This is followed by
nodal transmissivity values being computed for the water table or water-
table artesian conversion problem Transmissivity coefficients are then
computed for the water-table problem in TCOF (COEF subroutine) Total
head values are then computed with the alternating direction implicit
procedure using the Thomas algorithim first along rows in the ROW section
110 and then along columns in the COLUMN section both in the COMPUT subroutine
Then if a solution is not obtained (because the error criteria for
closure is not satisfied) the MAIN program branches back to NEWIT1 subshy
sequent sections TRANS TCOF ROW and COLUMN repeatedly until a
solution at the particular time step is achieved NEWIT1 increments the
iteration counter and is immediately followed by NEWITO The program then
moves to the STEADY section of the COMPUT subroutine to check if the
closure criteria for steady state has been satisfied Output is then
printed in the OUTPUT section of COMPUT if steady state has been reached
or if the particular time step is designated for output
The program then branches back to NEWSTP (COMPUT subroutine) and
moves through the subsequent routines until the last time step in the
pumping period is reached Output is then promoted in the DRY section
of COMPUT if specified in input data If the last pumping period in
the problem has not been reached the program branches back to the
NEWPER section and moves again through subsequent sections otherwise
the program will terminate or start a new problem if one follows
This study was simulated as a steady state problem which can be
simulated by setting the storage coefficient of the aquifer and the
specific storage of the confining bed to zero and using one time step
of any length
111
Appendix E
Computer Data Sheets
RGSEA
10 ROSE HILL LANDFILL MODEL 20 30 40 LEAKAGE 50 60 70 CHECK 80 90 100 HEAD 110 120 1 23 IQ 100 5 001 37E-OU 0 130 100 001 0 0 1 4 0 - 1 - 1 1 - 1 - 1 i i i i i i 1
ISO 1 10 0 1547E-05 01 10 1 1 160 04642 200 200 1 1 i it
1QO 190
CARDS I THROUGH 19 - CODING SHEET
CHEAD
100 110 120 130 131 132 140 141 142 150 151 152 160 161 162 163 164 165 170 171 172 173 174 175 176 177 178 179 1BO 101 190 191 192
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 539
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 58
25
25
25
25
25
25 621
25
25
25
25
25 662
25 25
25
CARD SET 2 - STARTING HEAD MATRIX (FT)
193 194 IVb 196 197 190 200 201 202 210 211 212 220 221 222 223 bull 224 225 230 231 232 233 234 235 236 237 23B 239 240 241 250 251 252 253 254 255
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 23 25 25 25 25 25
25 25 - 25 25 25 25 25 25 25 25 25- 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 - 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25
25 25
25
25 25
25 25
25 25
25
25 25
25
25 25
25
25
25
25 25
25 25
25
25 25
25 25
25 25
25
25
25 25
25
25 25
CARD SET 2 - STARTING HEAD MATRIX (FT) - continued
STORC 1512 FRI 19 FEB 82
100 110 -1 -1 - 1 - 1 0 0 120 130 140 ISO 160 170 100 190 200 210 220 230 240 230 251 260 261 262 263 270 271
CARD SET 3 - STORAGE COEFFICENT
LEAK
100 110 120 02 130 _ 18 02
I ltu 18140 025 150 02015015015 19 deg25
02 160 022 bull-laquo- J1 5 j 1 z laquo- l^
170 015 180 016 laquo02
190 016 OE025
200 02504019022021025 2 5 i S lt03 0252i2 n
230 030 deg23 deg2 deg2 deg2 -02023023 240 022 250 022025025 02
027043 013025
30() 025025025 310 025031 320 024025
CARD SET 5 - AREA OF STEAMBEDAREA OF NODE
120
Appendix F
Bibliography
121 BIBLIOGRAPHY
1 Agpar MA and 0 Langmuir Ground-Water Pollution Potential of a Landfill Above tne Water Table Groundwater V 9 No 6 1971 pp 76-96
2 Allen William B Hahn GW and RA Brackley Availability of Ground Water Upper Pawcatuck River Basin Rhode Island USGS US Government Printing-office GS 66-624 19bb
3 Annual Book of ASTM Standards Part 31 Open Channel Flow Measurement of Water and Waste Water by Weirs D 2034-68 1975
4 Annual Book of ASTM Standards Part 19 Infiltration Rate of Soils in Field Using Double-Ring Infiltrameters D 3385-75 1975
5 Baeaecner MJ and W BacK Hyarogeological Processes and Chemical Reactions of a Landfill Ground Water V 17 no 5 1979 pp 429-437
6 Beck WW Dunn AL and Grover H Emrich Leachate Quality Improvements After Top Sealing1 8th SHwRD MERL Symposium 1982
7 Beckman WK Transient Modeling For Estimating Sustained Aauifer Yield master thesis presented to the University of Rhode Island Kingston RI 1978
8 Bhattacharya PK and HP Patra Direct Current Geoelectric Sounding Elsevier Publishing Co New York 1968 135 p
9 Bouwer H Ground Water Hydrology McGraw-Hill Book Co New Yoric 1978 p 378
10 Braids 0 Cocozza pound Fenn D Isbister J Rous P and B Yarc Procedures Manual for Ground Water Monitoring at Solid Waste Disposal Facilities Environmental Protection Agency530SW-611 Cincinnati Ohio 1977
11 Cartwright K and MR McComas Geophysical Surveys in the Vicinity of Sanitary Landfills in Northeastern Illinois Groundwater V 6 no 5 1968 pp 23-30
12 Cartwright K and Fd Sherman Jr Electrical Earth Resistivity Surveying in Landfill Investigations Reprinted from Proceedings of ohe lOtn Annual Engineering and Soils Engineering Symposium Moscow Idaho 1972
122 13 Clark TP Survey of Ground-Water Protection Methods for
Illinois Landfills Groundwater V 13 no 4 1975 pp 321-331
14 Dunne T and LB Leapold Water in Environmental Planning WH Freeman and Company San Francisco 1978
15 Faro DG Upgrading Hazardous Waste Disposal Sites Remedial Approaches US Environmental Protection Agency500SW-677 Cincinnati Onio 1978
16 Fenn DG Hanley KJ and TV Degeare Use of the Water Balance Method for Predicting Leachate Generation From Solia Waste Disposal Sites US Environmental Protection Agency530SW-lfa8 Cincinnati Ohio 1975
17 Geisser 0 An Electric Analog and Digital Computer Model of the Chipuxet Ground Water^ Aquifer Kingston Rhode Island master thesis presented to the University of Rhode Island Kingston RI 1975
18 Hahn GW Groundwater Map of the Narragansett Pier Quadrangle Rhode Island Rhode Island Water Resources Coordinating Board GWM 5 1959
19 Hemsley William T Koster C Wallace Remedial Technique of Controlling and Treating Low Volume Leachate Discharge USEPA National Conference on Management of Uncontrolled Hazardous Waste Sites Oct 1980
20 Hughes GM RA Landon and RN Farvolden Hydrogeology of Solid Waste Disposal Sites in Northeastern Illinois Final Report to US Environmental Protection Agency PUD SW-l^d Cincinnati Ohio 1971
21 Keller GV and FC Frischknecht Electrical Methods in Geophysical Prospecting Pergamon Press New YorK NY 19bb
22 Kelly WE West Kingston Landfill An Evaluation of Its Effect on Ground-Water Quality Rnoae Island Water Resources Board Water Information Series Report 1975
23 Kelly WE Geoelectric Sounding for Delineating Ground-Water Contamination Groundwater V 14 No 1 1976 pp fa-10
24 Kelly WE Ground-Water Pollution Near a Landfill ASCE Environmental Engineering Division Journal V 10 No EE6 Dec 19b pp nay-nyy
25 Kelly WE personal communication January 1982
123
26 Kelly WE and OW Urish A Study of the Effects of Salt Storage Practices on Surface ana Ground Water Quality in Rhode Island NTIS FHWA-RI-RD-8001 1981 54 p
27 Kimmel GE and OC Braids Leachate Plumes in a Highly Permeable Aauifer Groundwater y 12 no 6 1974 pp 388-393
28 Klefstaa G Senalein LVA ana RC Palmauist Limitations of the Electrical Resistivity Method in Landfill Investigations Groundwater V 13 No 5 1975 pp 418-427
29 Landon RA Application of Hydrogeology to the Selection of Refuse Disposal Sites Groundwater V 7 no b 19b9 pp 9-13
30 Lang SM Bierschenk WH ana WB Allen 1960 Hyaraulic Characteristics of Glacial Outwash in Rhode Island Rhode Islana Water Resources Coordinating Board Bulletin No 3
31 LeGrand HE Patterns of Contaminated Zones of Water in the Ground Water Resources Research v 1 No 1 1965
32 Palmauist R and L Sendlein The Configuration of Contamination Enclaves from Refuse Disposal Sites on Floodplains Grouna Water v 13 no 2 1975 pp 167-181
33 Pinder GF A Digital Model for Aauifer Evaluation Techniaues of Water Resources Investigations of the US Geological Survey Bk 7 Cl 1970
34 Purushattam D Tamxe GR and CM Stoffel Leachate Production at Sanitary Landfill Sites ASCE Environmental Engineering Division Journal V 103 no EE 6 Dec1977 pp 981-988
35 Remson I Fungaroli AA ana AW Lawrence Water Movement in an Unsaturated Sanitary Landfill ASCE Sanitary Engineering Division Journal v 94 no SA2 April1968 pp 307-316
36 Rosenshien JS Gouthier JB and WB Allen Hydrologic Characteristics and Sustained Yield of Principal Ground-Water Units Potowamut-Wickford Area Rhoae Island USGS US Government Printing Office GS 67-324 1968
37 Roux PH and B Vincent Electrical Resistivity Evaluations At Solid Waste Disposal Facilities US Environmental Protection Agency SW-729 Cincinnati Ohio 1978
124
38 Salvato JA Wi lk ie WG and BE Mead Sanitary Landfill Leaching Prevention and Control Water Pollution Control Federation Journal v 43 no 10 Oct 1971 pp 2084-2100
39 Sawyer CN and PL McCarty Chemistry for Environmental Engineering McGraw Hill 1978
40 Stellar RL and P Roux Earth Resist ivi ty Surveys - A Method for Defining Ground-Water Contamination Ground Water v 13 no 2 1975 pp 145-150
41 Todd OK Ground Water Hydrology John Wi ley and Sons Inc New York 1959
42 Tolman AL Ballestero AP Beck WW and GH Emrich Guidance Mannual For Minimizing Pollution From Waste Disposal Sites US Environmental Protection Agency-500SW-677 Cincinnati Ohio 1978
43 Trescott PC Iterative Digital Model for Aauifer Evaluation US Geological Survey Open file report 1972
44 University of Rhode Island Academic Computer Center CalComp Contouring Manual
45 Warner DL Preliminary Field Studies Using Earth Resistivity Measurements for Delineating Zones of Contaminated Ground Water Groundwater v 7 1969 pp 9-16
46 White EF A Report to the Town of S Kingstown Utility Survey Engineering Corp 1967
47 Zohdy AAR A Computer Program for the Calculation of Schlumberger Sounding Curves Over Horizontally Layered Media Using the Method of Convolution US Geological Survey Denver
48 Zohdy AAR Eaton GP and DR Mabey Application of Surface Geophysics to Ground-Water Investigations Technidues of Water-Resources Investigations of the US Geological Survey Book 2 Chapter 01 Washington US Government Printing Office 2401-02543 1974
background
The South Kingstown landfill is in a geologic setting that is
very similiar to the nearby West Kingston landfill This is located
about 3 miles west of the South Kingstown landfill and has been
studied to assess leachate effects on groundwater quality using
specific conductance as an indicator of contamination levels
(222ltt) Both sites were located in abandoned gravel Quarries which
were filled in with refuse to create the landfill
In the literature numerous authors have shown that the character
of contaminant plumes from landfills are largely dependent on the
local geology and geohydrology A study on Long Island (27) in
similiar glacial material illustrates that the Quantity of flow is
dependent on the hydraulic conductivity of tne aauifer the
hydraulic gradient and the vertical cross-sectional area of the
aauifer it flows through This is expressed as Darcys Law (41)
Q = KIA
wnere Q = flow quantity
I = hydraulic gradient
K = hydraulic conductivity of the aauifer
A = vertical cross sectional area of the flow area
Specific conductance was used as a contaminant tracer to show that
the plume from the landfill flowed downgradient and vertically
through the full thickness of the aauifer A study in Iowa (32)
indicates that the size ana shape of the contamination outflow from
a l a n d f i l l can be predicted from existing geohydrologic conditions
and that the horizontal shape of the outflow extends downgradient
8
from the source and parallel to ground-water flow lines Other
parameters which control the extent of the contaminant plume are
dilution and dispersion in the aquifer and the adsorption properties
of the aauifer material (31)
The amount of leachate generated depends largely on the amount
of water that infiltrates through the landfill to increase tne water
content of the refuse in the landfill The precipitation recharge
that percolates down through the unsaturated zone to the water table
moves in a vertical direction (35) Surface runoff soil moisture
storage losses and evapotranspiration account for tne precipitation
that is not transmitted tnrough the unsaturated zone of aeration
(3315) Upon reaching the saturated zone the water enters the
ground-water flow system Ground-water mounding has been reported
in landfills due to the decreased hydraulic conductivity of
compacted refuse relative to surrounding aauifer material (20)
Chemical processes within the landfill leachate outflow and
surrounding soil cation exchange capacity relative to water duality
of the surrounding aduifer have been studied in Pennsylvania (1) anu
in Delaware (5) A procedures manual for ground-water monitoring at
solid waste disposal facilities was developed by the US
Environmental Protection Agency (USEPA) (9)
Several reports have been written that investigate site
selection design criteria and remedial measures to correct
leachate problems (29) A survey of ground-water protection methods
for landfills in Illinois studies relationships to the water table
theory of liner installation and monitoring devices (13) Sanitary
Landfi11-Leaching Prevention and Control presents a review of
preventative methods such as means to minimize infiltration
interception of ground-water and other pollution control measures
(2 37) A study in Pennsylvania on actual measures implemented to
collect and treat a landfills leachate discharge presents a site
specific study (19) Leachate Quality Improvements After Top
Sealing1 shows that by minimizing infiltration at a landfill in
Connecticut the outflow leachate water quality can be improved
dramatically and contamination plume reduced significantly (6) The
most comprehensive reports on remedial approaches to upgrading waste
disposal sites and ground-water protection methods have been
compiled under USEPA contract (1542)
To assist in evaluating remedial measures the US Geological
Survey (USGS) computer model Iterative Digital Model for Aduifer
Evaluation was used It was originally developed as a model for
simulating two-dimensional aauifer problems (33) It had been
updated since its original development to accomodate different
options (43) This model has been applied to glacial outwash
regions in Rhode Island (717)
10
Description of Study Area
A map of tne landfill area (Fig Z) was obtained from tne town
of South Kingstown The excavation to the west of Rose Hill Roaa
the landfill area directly to the east and the presently operating
area to the east of the central stream comprise tne overall study
area This study will concentrate on the west landfill area whicn
has recently reached capacity and been closed to further dumping
This site received mixed refuse for the past 15 years The depth of
the excavation where the landfill presently exists was approximately
to bedrock in some places Tne exact depths of landfill material is
unknown
The landfill cover has been graded and sloped generally eastward
to convey surface runoff to the eastern side A sandy soil that was
excavated locally was used as tne cover material The northern
section has a vegetation cover and the recently filled southern
section has been seeded and mulched The six monitoring wells W
NW NE EC SE SC were placed by the town of South Kingstown to
provide water quality information
Referring to Fig 2 the west excavation stream drains the area
created by the excavation to the west of Rose Hill Road and flows
throughout the year The central stream drains a small watershed
area which lies to the northwest of the landfill and drys up during
part of the year These streams flow into the Saugatucket River
which flows throughout the year and is larger than the west and
central streams combined
11
The USGS Groundwater Map (18) was initially consulted to proviae
information on the ground-water flow patterns (Fig 5) and the
geology of tne area (Fig 6) The surficial geology borings and the
vertical geologic cross-section at the base of the study area
indicate shallow water table and bedrocic and a nearly constant
saturated thickness (18) Boring logs at the W well ana a point
approximately 150 feet south of it indicate glacial outwasn material
which is primarily sana with a trace of gravel over bedrock at a
depth of approximately 33 feet Borings at the east landfill area N
and S monitoring wells indicate the same aquifer material
(Appendix B)
The ground-water map developed by Hahn is taken as
representative of conditions existing prior to the excavation of the
I l andfill (18) This indicates water-table contour lines that run in i
a general northeasterly direction This means tnat flow was
originally in a southeasterly direction However contamination of
domestic supply wells on the west side of Rose Hill Road has
occurred (Fig 3) strongly suggesting that the original flow pattern
has been altered by the excavation to the west of Rose Hill Road and
the landfill to the east of it Domestic supply wells were formerly
located directly to the west of Rose Hill Road but were aoandoned
when they became contaminated from landfill leachate New wells
were located to the south and west away from the contaminant plume
of tne landfill In addition a well located at the northeastern
corner of the landfill was contaminated and a replacement located to
the east of Us former location on tne opposite side of the central
12
Legend scale 124000
mdash-40 mdashground-water contour elevation
Fig 5 Ground-Water Map
13
Legend feet
TILL
Fig 6 Geology Background Map
14
stream This second wel 1 also became contaminated Domestic supply
wells located near tne northwestern corner of tne landfill and
approximately 300 feet south of it nave remained uncontaminated
These well locations serve as an indication of tne extent of the
landfill contamination which is largely dependent on the groundwater
flow patterns To furtner investigate this problem and provide
substantial information on which to base the geohydrologic analysis
field studies of the area were conducted
15
Field Studies ana Procedures
A map of the lanafill and an aerial pnotograph of the area were
obtained A tracing of these maps superimposed upon another
delineates stream landfill and monitor well locations (Fig 2)
The field investigation concentrated on the west landfill area ana
its aajoining streams ana monitor wells The east landfill area and
the three monitor wells in that area are induced in the latter
phase of the study in oraer to expand the model area
A traverse which establishea tne monitor well elevations was run
using a Carl Zeiss level These were originally sitea in by the
town of South Kingstown using a local USGS reference datum number 40
(18) The wells of known elevations then served as benchmarks for
referencing adjacent stream elevations This in combination with
the depth to water table measurements at each well enables tne
water-table surface geometry of the area to oe visualized
Water-table measurements of the west landfills wells were recordea
over a ten month period to record fluctuations (Fig 7 Table 1)
The east landfill areas wells were monitored for a five month
period Using a given water-table condition a ground-water map was
developea of the area (Fig 4) This indicates an outflow from
the landfill primarily in a southeasterly direction and partially
in a southwesterly direction
Additional bedrock and water-table information was ootainea by a
seismic refraction survey at several locations along the landfill
perimeter A Bison Model lb70C Signal Enhancement Seismograpn was
used to maxe the surveys Lines were run (to a length of kOO feet)
16
17
w s p bdquo S bdquo s S S a laquolaquo _
s 2 8
V
r bdquo
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S
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t
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r
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5 a 3 7 3 m
5 s a ^
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M ^
^ c o 2 5 s 3 a S R
rd 3 y a O =J
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2
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r s s in
5 y
a s
5
3
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5 a
^ a
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s raquo
a
0)
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^ mdash
a j -
-3
C
g S
S
bull a
-
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2 s s 3 a bdquo s s $ Al s
(1) = $ s 3
S
c a a
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a s s - 3 S shy
4
0
a s
bdquo tfH
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3 a
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e bullfl s i s s a s a
3 nt
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18
in both directions to provide a check and permit accurate estimates
of the depth to bedrockThe seismic results allow approximate
interpretations of the depth to the water table and bedrocK thus
permitting an estimation of the saturated thickness Ground
elevations at the location of the seismic surveys were determined
from a topographical map and field siting From this information
water table ana bedrock elevations estimates were made Bedrock
contours are listed in Fig 8 In addition a table which
summarizes the seismic refraction results for the unsaturated
saturated and bedrock layers velocities and depths at each survey
location is presented in Table 2
Scream gauging stations were established on the two streams
bordering the west landfill (Fig 9) Three stations were placed on
the central stream These provide information on the influent or
effluent condition of ground-water flow in the upper sections of the
stream and ground-water baseflow from an area adjacent to the
landfill into the stream (Table 3)
The stream gauging stations used were 90deg V-notch weirs The
weirs located in the SE and SW positions were placed in the
streamoea with a liner of plastic upstream to minimize underflow
The weirs located in the NW and E positions were cut to fit in
recesses of concrete culvert pipes Concrete plywooa interfaces
were coated with roofing cement to minimize bypass flow Upstream
water pressure and a snug fit hold the plywood sections in place
All weirs were implaceo according to AigtTM reouirements and flowrates
calculated using the standard 90deg V-notch formula (3)
19
N
seepage West observat ion Landfill hole
Area
Legend landfill limit excavat ion limit
copyWNWNEECSESC monitoring well locations
= = = unimproved road -- WNES-number
seismic refraction locations
-40shy approximate bedrock contpur elevation
feet
Fig8 Seismte Survey Location
20
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rmdash on sr i i
M z Z
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1 gt fc^gtgt bullbull ^ ^ ^
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i gtgt rH oj on gt tgtshyCM ^ cO^-s CO ~ CO
CO CO J X fc^_ bull^gt bullgtgt bull gt gtgt bull gt CO
j_ jJ O pound- Jj -P O Li deg =fObullH co on f- ^ 3bullH CO CO O in 3bullH CO
g^ -^2
poundsect HO
eis
mic
3 CO in in in in in in co o n co o n
o -^ r oj in O rHCO CO rH bullrH bull rH =T OrH bull rH OJ f-CO 4J bull- CO 4J rH O0) J-)
gt CM gt CM gt CM 4J
CO N_^ m^
bull OJ
t t poundshyCO CO CO CO rH J3 gt r-t oj on gt r-i oj on gt gt r n o j o n
lto co lto CO T bull ii-4 laquomdash bullmdashH
bullo CO L L 0)
CM CO cc
21
N
545-594
seepage observation
hole West Landfill
0NE I47-509
Area
Weir 45
i487-531
0 EC Al3-467
Legend bullmdash landfill limit -bull---excavation limit r-s stream
copy WNWNEECSESCSEN monitoring well locations
= = = unimproved road
Weir location and elevation
feet
Fig 9 Weir Locations and Wate r Level Ranges
22
JT NO
S shy S
O
bull ry m
oa
NO
(M raquo 1 03 or NO m
JT O O raquo
O NO 03 (j
PW tn in ^4 fraquo
m CN) f O O (M Oj
mdashraquo 3 M
s cshy -raquoraquo
o in in ^
rjO
laquobull NO ON
o bull-lt ^
H fy (NJ
tjgt
1 4 03 O
o
o
03 CM
in0
0
7 raquo
9gt
IM i iev NO
i in
i ru
i 0 rsi -or^
sO NO
CO O
03 raquo
1 O3
pound o ro CNJ
03
tn B OJ
o 03
m oi
NO
(M
r
(M
CO i M 03
m N ltn ~+ ltM -
QJrH
O M O ^ ^r-
oo m
8 a
m
^ NO
8 fNl
rshy03n
m - in
o laquoO
bull3 as m o 03 03 4
i O
i ^
shy
O
ltM bull^
ON f tn H 1 4 raquo4 i-4 H P-t
^^ lt-l
r-laquo
^ 1 1 1 1
pound raquoraquo O)t o gtz
bull bull ltbull
lt2
1 pound OJ
3 oi g bull
pound
1 pound laquolt bull
3 bull o a
pound
5 laquo15
f bull 3 Jl s
5bull 1 5
23
A field study to determine the infiltration capacity of a
section of tne landfill topcover was conaucted A modified version
of a double ring infiltrometer was used to study infiltration rates
(4) The cylinder diameters useo in this study were 8 inches and 18
inches A constant head of 6 in was maintained in the
infiltrometer and rates of infiltration were determined Tnese
results and an analysis of surface infiltration into the landfill
are included in tne analysis and discussion section
Specific conductance levels in the monitoring wells in the
streams bordering the landfill and at observation holes near the
landfill were measured (Fig 10) This is a good indication of the
mineralization of water (39) Specific conductances were measured
intermittently over the ten month period to develop a picture of the
extent and degree of contamination in the wells (Fig 11 Taole4j
and in the surface contamination monitoring locations (Fig 11
Table 5) A comparative standardization of the Beckman (short and
long probes) and YSI specific conductances is in Appendix C
A surface electrical sounding using the Schlumberger array was
conducted adjacent to Rose Hill Road at the R-l location (Fig 12)
in an attempt to delineate the vertical extent of the contamination
zone Well W was used as a centerpoint and a reference for
water-table depth pore water conductivity and depth to bedrock A
Schlumberger array electrical resistivity sounding was also
conducted in an uncontaminated area at tne R-2 location (Fig 12) to
provide a comparison background interpretation A seismic
refraction survey N-4 was conducted at the same location (Fig 8J to
24
N
excavat ion
Seepage West observat ion Landfill hole
Area
Stream 1 Seasonal observation 0 EC
hole
East Stream2
Legend sw Weir landfill limit j--1--^ excavation limit
copyWNWNEECSESC monitoring well locations
== unimproved road
feet
Fig 10 Surface Contamination Monitoring Locations
25
8000T
7000
O bull U) W6000
Legend
0 sc A NE O W
A SE O N W
a EC
1 O N D J F M M
Time months Flg11 Flucuatlon In Specific Conductance in Wells
26
Table 4 Specific Conductances in Wells (pmhoscm at 25degC)
West East Landfill Landfill
Date NW NE EG SE W SC N E S
81581 851 938 236 2356
102981 171 3268
11381 3268
111081 304 988 1100 258 3800
111481 426 2736 1216 186 4560
111781 304 3610 433 389 4560
121981 380 1406 129 103 380
1982 160 152
31582 274 760 1064 61 334 8000+ 182 53 84
52182 450 1500 1125 112 712 8000+ 175 255 150
52282 425 1320 1200 110 850 180 320 170
27
O
ct c r i c o o o o o c M o m o in CO CM unp^
3bull t- fmdash o^ co tmdash vo co in co cmdash co in a
bull bull1 1-1 trade4 rH rH^ CO 4)2
~ plusmn4J o O CM ^_
o n CO vO J oraquo 0C0M
cu rH rH rH rH rHin tmdash
3 iCM 4J
^j CO CO
E O0 ltU -H n o c E
See
pag
se
rva
t
rH O in 0 0 O O 0
O o x rH Cmdash
0 0n
cu rH mdash O tmdash X o o o o c o o o o r H r H i n o i n i n o O
bull L in oo co oo oo o cy cr o rH CM o cr ONc fcJ bullH on en m m rn c^n rH rH rH0 pound CO 3 CO
t CM0gt s o o o in rA n ^o oo in tmdash oo 0gt zr =r a- JT JT$_
T)C CO
~ E CO ^ _bdquo ltu CO g r H r n c n i n o o r H r H
vgtO ^D O ^^ ^O CO ^^ ^^ JJ 2 4) rH rHCO t
c CO
CO c 9) rH 0
CO -^ C c CO ltuo famp O trade t iH
0
bullo co n ^
oS
o ^^ bullH m
i co rn O CQ O1 CO CO 4) c2Q 3
CO
mdash^ bull cmdash CMin 1 gt rH vO vO O CTgt CO
s CTgt CO OO Ogt Craquo- tmdash cu O CO rH z 0
bull_bulllaquo
H bull L o in r in o oo in 3 rfy ff^ tir f^ CO C^~
4)bull
Z 3
^ ^ ^ ^ H r H r H r H r H rH r H C O r H C O a O C O a O a O C O C O r H i H r H CO OO - gt 0 0 ^ - gt ^ raquo - ^ ^ 1 - gt ~ gt - C O C O O O
U ^ raquo ^ - ~ raquo O ^ ^ O t ~ C O r H - r r ^ - ^ ^ JJ r H C M v O r H r H r H r H r H C M C M r H i n c r gt rH CO CM gt laquolaquo - - -^ bullmdash mdash bullraquoraquobullgt -v -v ^^
~ v O r H r H r H r H r H r H r H r H lt M C M C M CM O O r H r H r H r H r H r H r H r H r H r H r H r H rH
in rH cmdash
CO vo
CO vO
41 rH CO
CTgt rH raquo CM rH
cn CO
o 0 rn
CO cmdash
tmdash fshy
CM ao
iT rH
m
ogt ao
O o vO
CO t-
tmdash Cmdash
CM CO
rH CM
I
rH CT
O vO in
CTgt
in c^
CM ao
CM CM
in
-
bull
CO bO C bullH T3
cy ~
_
CJ E 3 ^ n c bullH
1-1
CO
^H
28
excavation
West Landfill
Area
Legend bullmdash landfill limit -bullbull--bullexcavation limit r~~s stream
copy WNWNEECSESCSEN monitoring well locations
= == unimproved road
electrical resistivity sounding
feet Fig12 Electrical Resistivity Sounding Location
L
29
allow estimates of depth to water table and bedrocic to be made
Soundings were carried out to 500 foot electrode spacings to insure
that hredrock was penetrated and to facilitate interpretation These
results and a discussion of the soundings interpretation are
included in the analysis and discussion section Schlumoerger
resistivity soundings were made using a Soiltest R-bO unit
30
Model Development
The USGS Iterative Digital Model for Aauifer Evaluation was
usea to develop steady state flow models of the study area (43) A
flow chart of the computer model and a brief explanation of the
subroutines usea is presented in Appendix D The stream locations
elevations and aauiferlandfil1 geometry and hydraulic properties
were input to the model to compute head values at each 200 foot
grid spacing node (Fig 13) The input data which is for the
existing excavation and landfill conditon is listed in Appendix E
The head values that are computed at each grid space are in turn
loaded into the CalComp plotting routine (44) where a grid spacing
is setup with the computed head values at each node The contouring
program linearly interpolates between these head values and
generates a contour map The computer simulated ground-water
contour map for the excavation and landfill is presented in Fig
14
The streams in the model generally serve as controlling boundary
conditions When using computer simulated geohydrologic models of
an area choosing the boundary conditions for the model that are the
same as prevailing conditions in the field is a critical step in
model development Extending the models boundaries to areas in the
field that have a minimum influx of ground-water across them
simplifies the proolem of calculating fluxes from outside the model
area The eastern boundary is bordered by glacial till which has a
low hydraulic conductivity estimated to be 67 ftday(2) This
contrasts to the high hydraulic conductivity of glacial outwash that
makes up the model area of approximately 107 ftday(3036j
31 N
o 9
bullO O
32
33
The Saugatucket River serves as the controlling boundary on the
east A small drainage area directly to the east of it provides a
minimal influx
Beyond the moaels northern boundary the glacial outwash valley
extends to the base of a till covered h i l l on the western half ana
on the eastern side extends along the Saugatucket stream Due to
the relatively large drainage area that lies upgradient from the
northern boundary a recharge flux eduivalent to 10 inyr over the
drainage area on the till hill and outwash area north of the model
area was input as underflow (Fig Ib) Part of this was input at
each northern boundary node Till has a lower infiltration capacity
than outwash so more of the precipitation w i l l be transmitted as
overland runoff resulting in a lower ground-water baseflow The 10
inyr of recharge that results in a ground-water inflow from the
combined till and outwash region represents an estimate that is
smaller than the 14 inyr recharge for glacial outwash areas in
Rhode Island (25)
The glacial outwash valley extends beyond the western boundary
No significant ground-water recharge flux was estimated at this
boundary A relatively low ground-water gradient exists to the west
of this which does not provide a significant flux across this
boundary Tne southern boundary is basically the outflow region for
the area and therefore would not reauire any ground-water flux into
the moael area across this boundary This boundary was set south of
the point that the streams in the model merge together Therefore
the streams which lie to the north of it are the controlling
34
scale 124000
Fig 15 Northern Drainage Area
35
boundary conditions The flux out of the downgradient outflow
region approximately eauals the influx from precipitation recharge
and boundary influxes
When tne stream configuration in the moael area are reviewed it
can be seen that they comprise a large portion of the boundary
area The screams can act as sources or sinks for water in the
model thus providing to and removing water from the aquifer The
leakance option was used in the model which provides for a confining
bed and aouifer area beneath the stream to be input
The leakance is defined as the hydraulic conductance of the
streambed divided by the streambed thickness which in this case is
taken as 1 foot The leakance value at each streambed node
restricts the flow between the aduifer and the stream The
streambed hydraulic conductivity is typically 01 the value of tne
hydraulic conductivity of the aduifer (717) The value 107
ftday was used for a streambed conductivity based on a value of
107 ftday for the aquifer The aduifer and stream hydraulic
inputoutput exchange at eacn node is calculated by initially
finding the difference between the initial field stream head
elevations and the computed head elevation values at the
corresponding nodes This head value is then multiplied by the
(Leakance value at each node) x (stream area of each node)
Therefore if the aduifer head was lower than the stream head the
stream would act as a source of water for the aquifer and vice
versa
36
Tne leaxance input at each stream node is the ratio of the
actual field streambed area in each node to the area of each node
which is 200 ft x 200 ft = 4 x 104 ft2 The west
excavations stream width is approximately 3 ft central 4 ft and
east 5 ft Therefore if tne west stream traverses the node
directly without meandering it presents a leakance of 3 ft x 200
ft4 x 104 ft = 015 Leakance and streamhead values were
input at each node to set up the stream flow parameters in the
models
A recharge value of 14 inyr over the entire area was input at
each node This represents a value of precipitation that is
transmuted into tne ground-water rather than being directly
evaporated evapotranspired through plants or overland flow
runoff The precipitation recharge flow from the stream into the
aauifer and boundary fluxes provide the model witn input flow
parameters
From analyzing the available information it was determined that
the study area lies within a glacial outwash area with a relatively
shallow bedrock The seismic survey around the landfill generally
indicates a depth to bedrock below the land surface of approximately
29-43 ft with corresponding saturated thicknesses of 19-33 ft as
seen in Table 2 This agrees with borings from tne USGS groundwater
map in the stuuy area (18j The seismic survey was run at a low
water table condition which was several feet below the high water
table level (Fig 9)
37
High water-table saturated thicknesses were used to develop
model parameters For the purpose of this model study the saturated
thickness was set at 30 ft except in the vicinity of well W where
there is a bedrock high (Fig 8) At this location a high water
table saturateo tnicxness of 8 ft was estimated In tne vicinity
the seismic survey was conducted the bedrock elevation at this
location is the highest and the saturated thickness the least Tnis
can be seen by an east-west cross section of tne landfill (Fig 16
The boring log for well W indicates a sand trace gravel outwash
material (Appendix B) Boring logs at the eastern landfill area N
and E indicate similar material On this basis the hydraulic
conductivity was estimated at 107 ftday (3036) Witn the
exception of the landfill and the bedrock hign areas the
transmissivity values were set at 107 ftday x 30 ft = 3210
fto day From the literature the hydraulic conductivity of the
landfill material was estimated at I ftday (19) The
transmissivity of the landfill material in tne nortnern section was
estimatea at 1 ftday x 30 ft = 30 ft^day or approximately two
orders of magnitude lower than the outwash In tne landfills
southern section the original excavation was not as deep as in the
northern parts The landfill material was estimated to makeup only
one half tne saturated depth the remainder being the original
glacial outwash material (Fig 17) Therefore the transmissivity
at the southern end was estimated at 15 ft x 107 ftday + lb ft x
1 ftday = 1620 ft^day These values were graded into the 30
ft^day values at the landfills northern halfway point These
38
were input as transmissivity values to the model at their respective
locations This model did not use the water taole option so
water-table fluctuations did not affect the transmissivities
39
O
-8 Oi0
co o
CO
o Oin
3
O or
bullo c 10
ogt o laquorf o
c o o e 0i
CO to o k O
co CO LU I
09 O
bullo c 01
CO
C9
UO|JBA9|a
40
o ltD
a o co
o10
o o
C O
coI co co O w O
o CO I
JC
l_ o Z
bullo c 09
CO
oin uo|BA8|a
Model Calibration
A simulation was run using the initial estimates of stream
parameters aquifer and landfill hydraulic conductivities
transmissivities boundary and recharge conditions to approximate
water taole conditions in tne fiela Initially the existing
condition of the excavation area to tne west of Rose Hill Road and
the landfill to tne east were modeled in order to calibrate the
model to current field conditions as shown on Fig 4 The simulated
well values (Fig 14) fall within tne range of field values (Fig
9) The resulting contours also provide an approximate matcn This
can be seen by comparing Fig 4 with Fig 14 An additional check
was to match the flow loss and gain in the streams between tne weirs
in the central stream which w i l l be discussed later The
simulated flow value from the excavation drainage stream is the same
as that measured at the SW weir location Having calibrated the
model by approximately matching well water levels nead contours
and scream flow values different field conditions and possible
remedial measures can be simulated
When the model grid was laid out over the study area as viewed on
Fig 13 the stream configuration rarely traversed the grid nodes near
their central axis When the stream locations were input to the
computer the information was documented as crossing the central axis
of the grid nodes The result of this is a slight aberration when
the actual stream configuration is laid over the computer graphics
head contour output The streams dont always cross the groundshy
water contour at the logical location Rather than modifying the
actual stream configuration to adjust then to the computer output
their actual locations are presented
42
Simulations
i The primary focus of the computer modeling is to analyze flow
patterns under changing conaitions in the near vicinity of tne raquo
landfill The study areas overall flow patterns as they exist
today are first presented in order to realize the lateral east-west
head contour lines between the stream that directly borders the
landfill on the east side and the SaugatucKet stream (Fig 14)
This indicates a general southerly flow direction in that area As
different conditions are modeled these contours generally maintain
their east-west orientation In order to facilitate interpretation
of flow patterns in the near vicinity of the landfill flow patterns
to the west of the stream that borders the east side of the landfill
r are presented in the subseauent models
L- Natural Conditions
The results of modeling the original natural conditions are
shown in Fig 18 The excavation and stream to tne west of Rose
Hill Road and tne landfill did not exist in this simulation The
southwestern boundary consists of a drainage stream that was
delineated using an aerial photograph and stream elevations were set
using the topographical map The USGS ground-water map (18) was
used to estimate head values between the west excavation and north
streams These were input to the model as constant heads on the
models western boundary The resulting simulation generally matches
the southeasterly flow direction that is indicated on the
ground-water map (Fig 5)
A3
Legend
x-^- stream 400 = = = unimproved road
I f ee t
Fig 18 Natural Conditions
44
Excavation Without Landfill
The condition of the excavation to the west of Rose Hill Road
with its resultant drainage stream without the landfill was modeled
next (Fig 19) The extent of the excavation ana the location of
the new drainage stream were delineated using the aerial
photograph The west stream elevations were sited in the field and
used in the model The concept of a confining streamoed layer was
excluded in tne excavation drainage stream under the concept tnat no
significant organic layer had been built up within the 25 year
period that the excavation had been initiated Head values between
the west and north stream boundaries were interpolated and input as
constant head values on the northwestern boundary The west
excavation drainage stream creates a condition that alters the
natural ground-water flow patterns by creating a more southerly flow
condition the drainage stream providing a more immediate surface
outflow in that area
Landfill Without Excavation
The hypothetical case of a landfill without the excavation was
modeled next (Fig 20) The low hydraulic conductivity zone of the
landfill changes the natural flow conditions and creates noticeable
mounding This is evidenced by the decreased spacing of the head
contour lines and deviation from the lateral contour lines of the
natural conditions and higher head values (Fig 21)
45
Legend
excava t i on s t ream
400 unimproved road
f e e t
Fig19 Excavat ion without Landfill
46
Legend
landfill limit
bull - s t ream 400 copy WNWNEECSESC
monitoring well locations f ee t bullbull-bull=bull unimproved road
Fig 20 Landfill without Excavation
1
oin CM
bull
m u
0)rf
oO
bullo 9
bullo 9
o rf o o CO 1
lt0inO O
T ^ogt
c o
47
o9 aI 0)
ot_3 O laquolaquo coO bull3 OJ oX
bulla caj
CM
UO|IBAraquo|
48
Landfill ana Excavation
The condition of tne existing landfill and the excavation with
the dam is the next condition modeled (Fig 22) The ground-water
elevations used to calibrate tne model correspond to an actual high
water table condition Between the NVJ and pound weir a streamflow loss
of approximately 102 gpm occurs aoout 60 percent of this flow is
lost at the dam site which maintains a head of b-6 feet over an area
of approximately 1800 feet^ This approximates a field value of
1144 gpm influent to the aduifer between the NW and E weir on ]2
December 1981 (Table 3) From the E weir to the SE weir a net
increase in flow occurred of 74 gpm which corresponds to field
increase of b62 gpm
The surface runoff from tne landfill flows primarily toward tne
eastern side of the landfill Increases in water-table elevations
on the eastern side after heavy rains such as the 11 November 1981
storm indicates that this runoff increases outflow gradients to the
stream and therefore increases streamflow Surface runoff input is
not modeled which explains in part why field stream inflow values
are slightly higher than model predictions especially for periods
after a storm has occurred The flow from the SW weir located at
the southern end of the excavation represents drainage outflows from
that area The net flow calculated in the model was 140 gpm
which approximates field conditions of 1642 gpm on
December 9 1981
49
d f l f reg N E
shy
Legend
landfill limit -bullgt-bullgt- excavation ^-N_X- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road
-40mdash approximate groundwater contour
400
feet
Fig 22 Landfill and Excavation with Dam
50
The modeled flow patterns suggest how the various contamination
zones around the landfill have developed to their present state
They indicate a flow to both the southeast and southwest on their
respective sides of the groundwater divide Evidence of a
southwesterly contaminant flow is presented when the continued high
specific conductance contaminant level in tne observation seepage
hole is realized (Table 5 ) In addition the specific conductance
increase in the west excavation stream is evidence of an influent
contamination flow
Contamination flow to the eastern and southeastern side of the
landfill is obvious High specific conductance levels in the wells
on the eastern side (Table 4 ) a specific conductance increase
between the E and SE weirs (Table 5 ) and contamination in the NE
domestic supply well (Fig 3) present conclusive evidence of
contamination to the eastern side of the landfill
An anamalous condition that exists is a domestic supply well
located approximately 300 feet due south of the landfill remains
uncontaminated (Fig 3) Flow patterns indicate that contamination
would be transported from the landfill south to this area
(Fig 14) One explanation is that a pocket of clay at the southern
end of the landfill area was discovered in the original excavation
for the landfill (lt6) This evidently prevents leachate from
reaching this wells radius of influence
51
Summer Conaitlon
As described earlier during dry months of the year the stream
that normally borders the northern and eastern side of the lanafill
may dry up as far as a point southeast of the E well Tnis
condition existed from the 15 August 1981 to the 27 October 1981
period when streamflow commenced in the northern part of the stream
yet did not overflow the north dam until 17 November 1981 This
created the present day continuous flow condition throughout the
stream These summer conditions were modeled by removing the stream
above the aforementioned location while other conditions remained
the same (Fig 23) Summer condition well water levels listed in the
model generally match field low water table conditions (Fig 9)
Because there is no stream upgradient from the landfill to provide a
stream head and infiltration through the streambed groundwater
runoff from the area north of the lanafill is the controlling flow
input In these moaels an average recharge of 14 inyr was used
which represents a yearly average The summer recnarge conditions
are prooably lower given the effects of decreased rainfall and
increased evapotranspiration during the summer months A domestic
supply well whicn exists northeast of the landfill (Fig 3) nas a
greater potential to be contaminated from the lanafill at tnis time
than when the stream is flowing Flow patterns from the landfill
are such that during an upper stream no-flow condition groundwater
flow patterns are more in an easterly direction than in a
southeasterly direction The stream would act as a source of
infiltrated water upgradient from tne landfill and provide a
52
I ^N gt i I i j i -r- -bull- bullr -T- t- -r- i- TJ JV
bullbullT laquo ^ O - laquo bdquo xi cshy
H r^~ I -~- --^ X- = mdash x^ N
^--^ A bull O^NW -v - gt-bull Ni i I _____mdash - bull laquo l - mdashmdash 1 deg I ^ltv I C
I reg NE A
Js bull vbull A ~ - v T gt- ^ ix - N
-5Z- | N TfS lV I -bull bull iA i gt gt I ^ bullr-Ky L bull 1 _- copy]wgt-- - bull- mdash - - shy
= r Y ~mdash ltmdashA A
^^-lt A _ - - - - bull Hmdash - reg EC x ^-mdash mdash I ---mdash_mdash -t-V-^N - y
I- -bull - r x i X
V ^ 7 I -v (^~~^^r ^^^
sc Emdash-bull vV JI - - - ~ r )N y- -
X - bull r bulllt
^bull^ y y Jlaquo^ - -lt shy
T s^ lt^ ^ +^-b (
X
Legend
landfill limit j-j-bullraquobull excavat ion gt^ -x- s t ream
reg WNWNEECSESC monitoring well locat ions
= == unimproved road fee t
Fig 23 Summer Condition
400
53
constant head across tne northern section of the landfill This
would tend to orient the flow in a more southerly aowngradient
direction In addition the stream which flows adjacent to the
northeastern well could provide a source of infiltrated clean water
to it which would minimize the possible contamination from landfill
leachate
Without Dam
During tne spring scream flow condition the dam failure which
occurred between the 15 March 1982 ana 9 April 1982 monitoring
periods decreased flow to the aauifer and landfill This eliminated
the 5-6 foot head difference over a 19000 ft^ area which had
created a larger area and elevation head for infiltration to occur
The condition without the dam was modeled by reducing the area
encompassed by the dam to a 4 foot wide stream channel thus
reducing the leakance value at that node (Fig 24) The flow change
from the stream to the aduifer between the NW weir and E weir
reduced the model flow loss to 50 gpm Tnis corresponds to the 9
April 1982 monitoring period which indicates a 30 gpm loss
As compared to the previous flow loss in the upper stream
sections to the aauifer the 21 April 1982 and 22 May 1982
measurements between the NW and E weirs indicate a flow gain The
streamflow conditions have changed from an influent
stream-to-aauifer condition to an effluent aduifer-to-stream
condition that increases flow downstream
54
Legend
landfill limit j--i--i- excava t ion x-gtmdash^- stream 400
copy WNWNEECSESC monitoring well locations
= == unimproved road f e e t
Fig 24 Landfill and Excavation without Dam
55
Analysis and Discussion
In order to fully understand flow patterns and Quantify leachate
outflows at the landfill it is necessary to arrive at an estimate
of flow inputs from precipitation ana upgradient sources In the
following analysis it will be demonstrated that the rainfall input
to the landfill is the factor which controls leachate generation A
calculation using the H inyr recharge over the area of the
landfill was made to estimate the leachate outflow due to rainfall
infiltration An estimated 134 gpm is generated from the entire
landfill area Simulation of the existing conditions (Fig 24)
indicates a groundwater divide in the landfill is located
approximately at the western third Therefore approximately 23 of
the generated leachate flows to the eastern side of the landfill or
9 gpm The effect of the flow input from the upgradient stream is
evident when tne summer condition witnout the stream is viewed
(Fig 23) Without the stream to infiltrate the landfill and the
recharge and northern boundary condition as the flow inputs the
head at the northern end of the landfill drops about 5 feet from its
previous value A flow pattern from the north central part of the
landfill to the eastern side indicates a 12 feet head difference
with recharge - but with the upgradient stream a 16 foot head
difference occurs Considering the transmissivity change the
stream would increase the leacnate outflow from the landfill
approximately 43 under a low water table stream influent condition
to the aauifer This would increase leachate outflow to the east
side to approximately 129 gpm This value approximates the
56
outflow at the SE weir location during the summer monitoring period
when the upper stream was not flowing (Table 3) The outflow from
the western third of the landfill whicn lies to the west of the
ground-water divide would be approximately 63 gpm
Realizing the importance of infiltration to tne landfill as a
major influence on the generation of leachate an analysis of this
w i ll be discussed An estimate of infiltration was made using the
precipitation recora for October ana November (Appendix A) During
this time period a minimum of direct evaporation ana
evapotranspiration occured and the grouna is not yet frozen The
top cover over the lanafill is generally 05 ft to 2 ft of local
sandy soil and subsoil availability determined what was used The
top of the landfill is at an elevation of 92 ft as compared to the
ground surface at well W which is at an elevation of 76 ft
(Fig 25) This compares to the well W water level which is at an
elevation of approximately 52 ft This creates a long path for
infiltration through the unsaturated zone The topcover generally
slopes eastwara at a grade of 2-5 The west side maintains a
relatively steep slope of 10-15 ft drop within 50 ft ana the north
and eastern slopes have a more gentle slope of approximately 10 ft
within 100 ft distance An unlined surface arainage swale channels
surface runoff from the northern section of the landfill past the
NE well to the eastern side ana low area in the vicinity of the E
well This has a drainage swale to an area near the stream but
doesnt directly connect to tne stream A poorly graaed drainage
swale exists on the landfills left side The landfill material has
57
excavation
seepage observation ^
hole
Legend bullmdash landfill limit -^--excavation limit r^s- stream
copy WNWNEECSeSCSEN monitoring well locations
--- unimproved road O location of amp Inf i l t rometers O
feet
Fig 25 Infi ltrometer Locat ion and Drainage Feature
58
been placed in 10-12 ft cells and covered with 1 ft of soil at the
end of each day The material has settled differentially creating
areas for depression storage
An estimate of the percentage of precipitation that infiltrates
the landfill was made from precipitation records recorded well
elevations and an estimated specific yield for the landfill
material The volume of water that infiltrated should eaual tne
specific yield multiplied by the well water level rise Several
recharge periods were studied using this relationship Once the
percentage of precipitation that has infiltrated is determined the
percentage that is translated into runoff is simply the remaining
percentage if evaporation is neglected
From the literature for a slightly inclined slope of 2-5
typical runoff coefficients range from 10-20 in either sandy or
heavy soil (16) The landfill cover is generally sloping to the
east which creates a long path (approximately 400 ft) before the
runoff reaches the steeper slope on the eastern side of the landfill
of 15-20 The long drainage distance creates a greater time for
rainfall to infiltrate Another consideration is the actual
capacity of the soil to conauct water into the soil which was tested
in the field using double ring infiltrometers An average initial
percolation of 8 mmhr the first hour and a subseauent rate of b
mmhr occurred (Fig 26) The 8 mmhr rate compares well with
other sandy soil infiltration rates (14) Therefore if the
intensity of the rainfall exceeded a 5 mmhr rate for several hours
59
CO + 09 o
E o
CO
o Z pound C
O
C9
o DC
CO
CD CM
ogt CO N- to -4 CO CM
jq tuu i U O | raquo B J J | | J U |
60
on a poorly drained surface the additional rainfall would be
translated into runoff because the soils infiltration capacity had
been exceeded
The initial 8 mmhr infiltration rate was due to the pore spaces
in the sandy soil being filled and the subsequent 5 mmhr rate was
percolation into the low permeability landfill material The tests
were conducted in November assuming a minimal evapotranspiration
and the field capacity of the sandy soil had been maintainea
The W well was used as representative of the water elevation
changes in the landfill because it is directly adjacent to the
landfill 900 ft distant from the upgradient stream This minimizes
the effect of infiltration from the stream and maintains a high
contaminant level During periods of high runoff conditions excess
surface water ponded in a poorly graded drainage swale on the west
side and directly adjacent to the landfill This influenced the W
well at a time the contamination level dropped (Fig 11) Before
this occurence in mid-December the rise of the W well closely
matches that of the SC well and a background well SK6 which is
located outside the study area (Fig 7) Therefore it was analyzed
as a valia indication of the water level rise during the mid-October
to mid-December period The monitoring of the SC well was
intermittent due to inaccessaoility because of 10 ft extensions
being placed on the well as the refuse was being filled in arouna it
61
A high rainfall period from 14 November 1981 to 1 December 1981
was chosen for the initial study period The effects of
evapotranspiration were neglected due to the cool temperatures
experienced at this time Therefore it was assumed that the field
capacity haa been reachea and tnat any additional input to tne
unsaturated zone would result in direct percolation to tne saturated
zone During the time period 14 November 1981 to 22 November 1981
029 ft of rainfall fell and the well W rose from 488 ft to 493
ft - a 05 ft increase During the next 8 day period there was no
precipitation yet the W well continued to rise to 4972 - a 042 ft
increase The slow percolation of water through the landfill
material would account for the latent rise in the well water level
From previous reports a specific yield for refuse was estimated to
be 028 (1920) This value is dependent on the original compaction
of tne material age and resulting consolidation
During the 14 November 1981 to 1 December 1981 period 029 ft
of rain fell and the well increased 092 ft The following
relationship is used to evaluate the infiltration value and runoff
I = (Sy) h
Sy = specific yield
h = well rise
I = volume infiltrated
I = (028) (092 ft) = 0261 ft
62
The difference between the precipitation and the infiltration is
the runoff (assuming no evapotranspiration) Therefore 029 - 026 =
003 and furthermore 003029 - 13 runoff This corresponds in
the literature to a typical runoff coefficient for an inclined
surface of 2-5
Analyzing a longer precipitation period from 18 October 1981 to
1 December 1981 a net precipitation of 043 ft (accounts for
evaporation) occurred less 10 for runoff or 039 ft infiltrated
This results in a 139 ft elevation increase The well water level
actually increased 132 ft shy only a 5 deviation from the
calculated
From tnis investigation it is seen that a large proportion of
the precipitation has the potential to be transmitted into the
landfills saturated zone Exceptions are wnen heavy precipitation
periods exceed the soil percolation capacity frozen ground prevents
infiltration and direct evaporation and evapotranspiration recycles
the ponded surface water and infiltrated soil moisture back to the
atmosphere In retrospect water temperatures within the monitoring
wells could have been measured to indicate thermal effects from the
landfill on ground-water temperature Ground-water temperatures
were assumed to be 50deg F (9)
63
Specific conductance measurements serve as an indication of
contamination levels These measurements are used to trace leachate
movement which represents ground-water flow patterns Factors which
must be considered when monitoring pollutants are the attenuation of
the leachate contaminants which occurs both in the zone of aeration
and the saturated zone The former is a more complete process
Dilution dispersion and cation exchange are the primary factors
involved in decreasing leachate concentration in the saturated
zone The glacial outwash materials of southern Rhode Island do not
have a cation exchange capacity or a high buffering capacity so
attenuation is simply by dilution and dispersion (22)
The NW well consistently exhibits relatively low specific
conductance levels even though it is in landfill material It is
situated in a drainage swale and ground water elevations range from
543 to 5944 This is several feet below the upgradient stream
elevation of 64 feet which is less than 400 feet away The bottom
of the wellpoint is at an elevation of 5312 feet well into the
landfill material Infiltration from the stream to the landfill has
occurred at this location
The W well is situated on a bedrock high adjacent to the
landfill approximately 900 feet from the upgradient stream and its
water level is higher in elevation than the excavated pit (West
Observation Hole) which is 300 feet directly west The W well
maintains a contaminated level A poorly graded drainage swale to
the west of the landfill provides areas for extensive ponding and
infiltration to occur which explains the drop in conductance after
a high runoff period
64
The SC well is located in landfill material and has a
conductance of over 8000 umhos This indicates that leachate is
undiluted The oottom of the wellpoint is at an elevation of 389
feet which is situated in the landfill material
High specific conductance measurements in the west observation
hole and well W and their relative elevations indicate a
west-southwesterly flow direction from the landfill Infiltration
recharge and leakance from the stream into the landfill provides the
necessary elevation to cause outflow in this direction
Contamination from the landfill to the surrounding streams is
evident (Table 4) During the period 15 August 1981 to 27 Octooer
1981 there was no flow in the stream that Borders the northern and
eastern side of the landfill until a point just south of the E well
was reached High specific conductance levels in the EC and NE
wells were recorded (1000 jjmnos) At a point directly east of well
EC a pool of water existed that was relatively uncontaminated which
is designated as the East Stream] location (Fig 10) At a point
just south of that (East Stream^ polluted water in the streambed
was flowing at a low rate This was measured at the SE weir
location and which had a high conductance also Flowrates varied
between 6 and 23 gpm and specific conductances were over 350
pmhos This low water table condition flowrate is the baseflow from
the eastern side of the landfill and indicates a southeasterly flow
direction from it
Streamflow commenced in tne northern part of the stream 21
October 1931 and the north dam oegan to f i l l Stream specific
65
conductances were low indicating a clean water source Tnis
continued until 17 November 1981 when the dam overflowed ana flow
throughout the east stream began A weir was placed at the Rose
Hill Road NW location and was compared to flowrates at the SE
location Flowrates decreased and specific conductances increased
between these two locations
To further investigate the condition of a lower flowrate
downstream than upstream an intermediate weir was placed at the E
weir location (Fig 9) This snowed tnat the stream from the M
weir to the E weir was losing water to the aauifer (influent
condition) and gaining water at the SE weir (effluent condition)
The condition of a net loss of water between the NW and SE weirs
remained until 19 December 1981 when a snowmelt rain condition
caused increased surface runoff and a net increase in flow at the SE
location Upon analyzing the March and April 1982 streamflow
conditions the expected case of a net ground-water pickup from the
E to SE weir continued The explanation for tne initial net loss of
ground-water is the fact that the leakance from the upstream section
was being discharged into aauifer storage to raise the ground-water
table to an eduilibrium level Upon reaching a high recharge
equilibrium steady state condition any additional input will
eventually be transmitted as baseflow out of the landfill and a
downstream net pickup will occur A hign water table condition
prevailed during the January through May period maintaining this
condition In April the north dam broke through reducing the head
in that area by 4-6 feet The 9 April 1982 monitoring revealed that
66
an influent condition remained between the NW and E weirs but at a
reduced rate The 21 April lower stream flow condition shows a
small pickup of water between the NW and E weirs indicating the nigh
water table and low stream flow conaitions combined with the absence
of the dam had changed the conditions to an effluent condition
This was evident in the May monitoring period
Evidence of contamination on both the western and eastern sides
of the landfill supports the existence of a ground-water divide in
the landfill The west stream which drains the excavated area to
the west of Rose Hill Road shows contamination pickup between its
northern section and the SW weir The W well and ooservation hole
indicate high contamination levels which reinforces the concept of a
contaminant outflow to tne west excavation stream
As shown previously flow towara the eastern side of the
landfill is evident from the nign specific conductances and specific
conductances increases in the stream This is especially evident
during low flow conditions when the stream starts at a point to the
east of the landfill and flows with high specific conductance levels
From the literature a relationship between specific conductance
and dissolved solids exists the dissolved solids (mg1) are
approximately equal to the specific conductance times a factor
ranging between 55 and 09 (39) in this case it is taken as
065 (41) The dissolved solids increase coupled with the stream
flow increases provides a basis of calculating the dissolved solids
outflow to tne stream This calculation method was used in a
previous study (26)
67
The relationship
=Cinout Coutflow Qoutflow - Cupstream Qupstream Qinput
where the numerator is the streamflow pickup and the C- and
Q-jnput is the concentration and flow input from the ground-water
This can be used to estimate dilution level outflows from the
landfill Initially this is used for the ambient ground-water
pickup between the E weir and the SE weir This entire flow doesnt
come from tne lanafill but much of it is conaucted in the high
transmissivity area between the lanafill and stream from upstream
leaxage ana surficial recharge Tnis is evident when this section
of the flow pattern is analyzed on Fig 22 Therefore the landfill
outflow is mixed with tne ambient groundwater flow which dilutes the
landfill leachate before it enters the stream To illustrate-this
concept a calculation using the 9 December 1981 monitoring is used
At this time a flow of 672 gpm occurred at the SE weir with a
specific conductance increase of 7 ymhos between the E and SE
weirs The dissolved solids increase would be approximately 795
Today in tne stream
Where
Co = 90 jumho at SE weir
Qo = 672 gpm at SE weir
Cus = 83 jumho at E weir
Qus = 606 gpm at E weir
Qinput = 66 gpm gain
Cinput = 154 jumho
68
The 154 jumho value represents the contaminant level in the
ground-water adjacent to the landfill
This relationship is applied to approximate the concentration
level dilution in the ambient ground-water between the landfill and
stream The aforementioned relationsnip is in turn applied to the
landfill outflow into the ambient ground-water flow adjacent to the
landfill The ground-water receives landfill leachate dilutes it
and then transmits it to the stream The previously calculated
value of 129 gpm was used as the outflow from the landfill
Co 154 jumho flows into stream
Qo = 67 gpm flow into stream
Cus = 83 jumho background level
Qus = 67 gpm - 129 gpm = 541 gpm
Qinput = 129 gpm from landfill
Cinput = 451 jumhos
Approximately tne same contaminant levels from the landfill (tbl
umho) are arrived at as existed in the summer streamflow conditions
when the upgradient ground-water flow adjacent to the landfill was
at a minimum
In addition to using specific conductance to define
contamination zones electrical resistivity can be used to indicate
contaminated areas The measured earth resistivity is inversely
proportional to the conductivity of ground-water Water containing
contaminants with high ionic concentrations are more electrically
conductive and will have lower resistivity values than surrounding
natural ground water Therefore resistivity methods can be used to
69
delineate plumes of contaminated ground-water that have hign
specific conductances This has been demonstrated by several
investigations (11122328374045)
In this study a Schlumberger vertical electrical sounding R-l
was made in an area of known contamination at the W well (Fig 12)
Given the geologic constraints provided by the well boring log a 4
layer computer model was used to match field survey values A
Schlumberger sounding R-2 in an uncontaminated area north of the
landfill in the same geologic setting was used to provide a
comparison background sounding (Fig 12) A seismic survey N-4 was
made to obtain water table depth and depth to bedrock as input
parameters to a four layer resistivity model (Fig 8) Tne results
of the electrical soundings have been tabulated in Table 6 and
plotted in Fig 27 and 28 respectively
The ascending portion of the field Schlumberger curves were
initially matched using a two-layer ascending type master curve to
provide an approximate depth and apparent resistivity of the
overburdened topsoil layer (8) Tne second unsaturated layers
apparent resistivity was determined by using the graphical
interpretation of total transverse resistance The total transverse
resistance is approximately eoual to the peak value of the curve
times the corresponding Ab2 distance it occurred at This in turn
is eaual to the sum of the first two layers apparent resistivity
times their corresponding layer depths
70
bullH
OJ bull bullH 4J CO CM
c ce G bullrH
j-gt ca c c a 3 ltu O L
co CO 0
bullo Q bull laquos c n 3 -U OrH f~ 3 bO ltn y CO O cc CO ^mdashN
QQ bull
bO bOJJ C C Ci_i
O l T i O O O O O O O O O O O O O O O O bullH bullH mdash^ bullo 0 C c3 f| 3 O raquo O CO CQ
CO
rH
CO O
L 4J
^ltU
i- 1 ^n ^b O 4-) bull2 CM bullH C OJ 1 -U bullH CO C L O a ^-^ 0) a
rH c a L CD ltu (1) 3 tlt bO cO I
3 a 0) a Q 4J laquoa e CO 3 (H bO c C O bullH
CO TJ C 3 bull
bull O bO -i-3
0 CO C O3- O G O O O O O O O O O O O O O O O O O O ft rt1 -raquo - t l S^ ft tfigt f I mdash^ K_ l_ raquo mdash I gt fgt I l 1
(1) 0 rH CO CJ JD o^^ CO CO CQH lts
71
Legend
A actual field measurement
-e- interpretat ion
10000 bull
6000 bull 5000
4000-
3000shy
pound2000| ltD
_ r 1000
09
5 600 pound 500 - 400
I 300 a a lt 200
100 10
Fig 27
20 30 4050 100
Distance AB2
Schlumberger Sounding
200
feet
R-1
400 600
72
loooot
6000 5000 4000
3000+
laquo2000 e
r 1000
raquo 600 pound 600 ~ 400
$ 300 a a lt 200
100
Legend
A actual field measurement
-Qmdashinterpretation
10 20 30 40 50 100 200 400 600 Distance AB2 feet
Fig 28 Schlumberger Sounding R-2
73
Formula T = f
Background Sounding (9000)(15) = (3110j (1 7) + gt2(8)
= 16214 n- ft
W Wel l Sounding (b200)(60) = (500) (2) + pound2(28)
= 13250 SL- ft
To determine a resistivityp3 value for the third layer a
graphical interpretation for the longitudinal conductance S was
used(48) This is eaual to the sum of each individual layers depth
divided by their apparent resistivity
Formula S = -r1 +~r-raquobull-ra
Background Sounding 0017 = yyg + ~^
= IbOU - ft
W Well Sounding 0285 raquo -ggg 7^3 J~
= 179 v-ft
These values were input to a program which calculates a
schlumberger sounding curve (47) The theoretical sounding curves
approximately match the field curve as viewed on fig 27 and fig
28 To provide a check on the apparent resistivity of the saturated
layer at the W well the following relationship was applied 1OOOO
= spec-jfic conductance (umhos)
74
At the W well the specific conductance was measured to be 3 00
jmhos at approximately 10degC
Assuming a formation factor of 45 for the glacial outwash (23)
material Archies law is applied to estimate an apparent resistivity
of the third layer (7)
fgt FF x p
A= 45 x 103-n-ft
A= 4G3 JL-ft
This is a reasonable approximation to tne 3i= 179^-ft calculated
analytically from the sounding curve interpretation
75
Remedial Measures
With the analysis of f low patterns and contamination zones
recommendations to minimize the environmental impact of the leachate
can be reviewed The basic technique is to minimize all sources of
water reaching the refuse so that leacnate production is minimized
The oiversion of precipitation by a relatively impermeable cover and
proper channeling of runoff would minimize percolation into landfill
material Caps and seals can be constructed of clays fly ash
soils soil-cement lime stabilized soil memorane liners
bituminous concrete and asphalttar materials (15) Proper
contouring and grading will help minimize infiltration If a soil
cover is used a vegetative cover can be planted which will utilize
some of the infiltrating flow through evapotranspiration losses
during the growing season By minimizing the length of slopes and
providing proper drainage channels tne surface runoff can be
conveyed to a downgradient area outside the recharge zone
Therefore this surface water will not increase leachate production
from the landfill Also by increasing the slope of the cover over
the landfill itself a higher percentage of runoff and lower
infiltration will occur
To minimize upgradient ground-water influx to the landfill an
impermeable subsurface barrier or intercepting trench could be
used Barriers can be made of bentonite slurry-trench cutoff walls
grout curtains or sheet piling cutoff wal ls extending to the bedrocic
or an impervious layer to effectively prevent water passage or
create a head loss that wil l lower the water table In addition an
76
intercepting trench which has a perforated drain at tne lowest part
of the water seepage zone could be used to intercept and divert the
entire flow
These possibilities have been evaluated with the help of the
model to determine workable solutions for this landfill The
primary concern is to eliminate leachate flows to domestic wells
Initially a simulation was run that eliminated recharge over tne
landfill area (Fig 29) This had a considerable effect on the
ground-water flow patterns of the landfill area The mounding that
had previously occurred under normal recharge conditions was
eliminated and a general drop in the water taole within the landfill
of 2-3 ft occurred The effect of eliminating recnarge over the
landfill when the upper stream is running would cause greater
infiltration from the stream as evidenced by only a 2 ft head loss
in the landfills flow conditions This is evident when comparing
Fig 29 with Fig 24 Tnis indicates that this measure would only
marginally reduce the resultant leachate flow from the landfill
material that lies below the water table In another situation
where there is not such a strong potential for upgradient flow this
measure has proven quite effective (6) In this case the landfill
cover consisted of four layers an intermediate sand and gravel
cover immediately above tne regraded waste materials a 4 inch sana
bed designed to protect the overlying membrane a ilO mil flexible
PVC membrane and an 18 inch final cover of sand and gravel
77
Legend
landfill limit -raquo- -^ -raquobull excava t ion x-^x- s t ream
400 copy WNWNEECSESC monitoring well locations
= -= unimproved road fee t
Fig 29 No Recharge over Landfill
78
Controls such as 10-30 mil polyvinyl chloride covers favor the
development of an anaerobic environment which increases waste
decomposition time and would necessitate installation of gas vents
at several locations on the landfill cover Tne integrity of tne
synthetic cap may be further threatened by subsidence which create
differential stresses on liners Settlement would create areas for
ponding and depression storage and eventually necessitate regrading
the landfill surface The landfills south-central area has oeen
filled within the last year and will prooably need to be regraded
due to settlement within the next few years
Another possibility for a liner would be a soil-bentonite
cover A layered cover consisting of natural materials with low
permeabilities such as bentonite clay followed by a layer of highly
permeable material such as sand and finally a layer of topsoil can
be used Due to potential drying out and cracking of the clay liner
a synthetic liner is the preferred method
The most immediate technique is to grade contour and vegetate
the landfill cover which has been done at this site Althougn an
impermeable cover would probaoly reduce the amount of leachate
produced it would not eliminate the upgradient flow and provide
guaranteed protection of wells in the vicinity of the landfills
northwestern section
A slurry trench along the northwestern perimeter of the landfill
would effectively cutoff upgradient infiltration and divert recharge
infiltration in a southeasterly direction thus removing possible
leachate outflows from the radius of influence of the neighooring
79
wells This has been simulated using the computer moael ana flow
patterns as shown in Fig 30 Contour lines are distorted in the
vicinity of the slurry trench due to the 200 ft nodal spacing
Transmissivity values of 1 ftday were input at the slurry
locations to simulate an impermeable barrier Tne surface recharge
at those nodes does not infiltrate the relatively impermeable grid
nodes at the slurry locations and flows to the edge of the noae
thus creating a dramatic head loss within a short spacing To
effectively simulate this a variable grid spacing should be used
with reduced node grid spacing at trench locations to eliminate
distortion The computer simulation shows that the slurry trench
could direct flow in the landfill area in a southeasterly direction
and away from endangered wells In addition it would reduce
upgradient infiltration from the stream into the landfill This
measure would prevent leachate from spreading beyond this carrier to
possibly contaminate neighboring wells
The combination of both the slurry wall and impermeable cover
would be ideal measures to minimize generation of leachate and to
stop its spread to neighboring wells The slurry wall without
recharge over it or the landfill is simulated in Fig 31 This
indicates a lower water table tnan eliminating the recharge to the
landfill The slurry wall has blocked upgradient ground-water flow
at its location to the landfill
80
Legend
landfill limit -laquo- j -laquobull excava t ion ^^- stream
copy WNWNEECSESC monitoring well locations
= = = unimproved road ssi slurry wall
f e e t
Fig 30 Slurry Wall
81
Legend
landfill limit j- j- J- excavat ion x-v^gt- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road s==s slurry wall
400
feet
Fig 31 Slurry Wall without Recharge Over It or Landfill
82
An intercepting drainage trench is considered next If a trench
was excavated to a 30 ft depth in the outwash material extensive
shoring would be required In addition difficulties would arise
when the trench was excavated below the waterline Tne trench would
be sloped to provide drainage and backfilled with a highly pervious
material to intercept and divert leacnate locally a conouit which
is perforated on the top to allow infiltration and unperforated on
its lower perimeter to permit continuous drainage to the collection
treatment center would be installed on the bottom of the graded
trench The difficulties involved in excavating below the water
table ano shoring the sidewalls to permit implacement of a drainage
conduit at a 30 foot depth make this option increasingly infeasible
83
Conclusions and Recommendations
The location of the South Kingstown landfill in permeable sand
and gravel glacial outwash material (107 ftday) combined with the
high hydraulic gradient across the landfill area (20 ft1600 ft)
creates a high potential for ground-water contamination to occur
This is intensified because refuse nas been placed below the water
table The low hydraulic conductivity of the compacted refuse (1
ftday) and the excavated area to the west of Rose Hill Road have
both contributed to modifying the original southeasterly flow
pattern These modifications have created a ground-water divide in
the landfill at approximately the western third section Tnis
results in approximately 13 of the leachate flow from the landfill
or 63 gpm flowing in a southwesterly direction and 23 or 129
gpm flows in a southeasterly direction Infiltration from
precipitation recnarge over the landfill (up to 9Upound) and from tne
upgradient stream during low water-table periods provides tne
necessary influx into the landfill Evidence of contamination is
clearly seen on both the east and west sides of the landfill which
reinforces the previously stated flow patterns
Of the several remedial measures reviewed the contouring and
grading of the landfill topcover and drainage swale provides the
most immediate protection The topcover has been graded mulched
and seeded to provide a low runoff slope generally to the east
The drainage swale on the left side of the landfill has improperly
graded sections which should be corrected Its northern section
could be drained into the northern sections swale and the southern
84
section drained to the southeastern section of the landfill Tne
point of the drainage swale which divides the northern drainage
swale from the southern one should be determined by a field survey
Cost is a major contributing factor when determining which
remedial measure is to be applied to the given situation For the
purpose of this report cost estimates are not presented but rather
the effectiveness and feasibility of the remedial measures are tne
primary considerations As was reviewed and simulated in the
computer models the slurry trench and impermeable cover over the
landfill are two viable options that would effectively provide
protection to the domestic supply wells in tne vicinity The
impermeable cover would eliminate precipitation recharge into tne
landfill yet drop the water table only a few feet due to upgradient
infiltration from the stream This would decrease the hydraulic
gradient thus diminishing the potential for a contaminant outflow to
surrounding wells The supply well of primary concern is one to the
west of Rose Hi l l Road marked well D on Fig 2 If contamination
occurs in this well the most effective measure would be to block
off leachate flow in this direction by installing a bentonite slurry
trench at the location indicated previously This would effectively
prevent leachate flow in the westerly direction and diverts it to a
more southeasterly direction In addition the slurry trench
precludes infiltration flow into the landfill from the upgradient
stream
85
Tnis report has effectively reviewed tne original ana existing
flow conditions and contaminant levels in the vicinity of the Rose
Hill landfill The purpose was to provide an understanding of
ground-water contamination patterns and study possiole remedial
measures
86lt
Appendix A
Precipitation Records
Monthly normal precipitation 1941 -197O
i$l Total monthly precipitation
KINGSTON RI
14
ia
^JO T I bullbullL
pound 111 laquobull
4
a
n
-
^
-
-
KS1JAN
^Ii R3 HB MAR
1
1 APR MAY
1
1 JUN
1981
JUL
-bullraquolaquo H
AUO SEP
K3~~f$s bull
_imdash
i1S 1
OCf NOV OtC
171 1 iI1
JAN HB MAR APR MAY
198
Fig 32 Precipitation Record
- - - -
IM 1 MtvJrflgtlgt c ortli-A t lUN I r nraquo rl - -
gt|MO CLIMATOLOQICAL OUSERV ATIONshyr-r bull JK gt raquo - 1
i5fWA I VAPOR Al IOH -bull AIM If MPCRATUM bullF 0 riccipn AT ION UNO IlMf
bull 14 H 14 H mdash Vshy ADDITIONAL DATA IfUAlUS OATt 1 bull raquof bull bull 1 ta
14 Hw rlaquo4 w bullbull bull 1 114 1mdash4 (llrl 1 1 1fl Hll
0 kmdash
Mraquo M4 raquo i T i 4 bullraquo-laquobull i i
Lgt f 1 21 S 1 Hbull - - bullbull -
ltJL 1 2 01 - - _ _ 1
mdash
-
1 12 _ Q I
mdash shy
mdash 4 (C ( - - fVi 1 - 0
1 (1
^ 1
Vvraquolaquo IJ1^ raquo CP O 3L 1 Z - i bull j-t-J
1 J
LH Vb T n 0
1 gt fl oo O ~l 2 L - bull 1 P )laquo jn iP IP - OOI L5L mdash shy
-t 84 ^(^^ ^fi P i flja 0 JO II 10 tl tcgt 7 J IV wllaquo
h l2L bull 0 lt -_ shy
-id VJ lt 3C 2 ft OOL -mdash
U 71 C1 Sr 2 13 2 nl JLJraquopound HP r M ltf1- (
IMe 2 ii O It
n jlt dl 1 1 bull o o-il ST i 1 i 25 2-x-1
-
ri
i tlL O mdash gtbull bullgtlt 1ft -o- is Oil So iJK 2-io otv u 31 fil loi 2 il Oll it Of wr is i1raquo -iZ 1 deg|0 01
M IT So - mdash
- 13 1 CT mdash i - mdash 21
shy
Tl Ci av ZUll IMT 0 IM Pe v _ 1) T) S) ii3( dlt Ii 2 lt^2 II li- S1 riivi To 7HX lt3lO 14 ^2- iTi I li 011 -- - -i -^IS no 5^ or i | T Jift laquoV OoH bullla It Va iCO mdash L OIL 11 bullvf poundgtpound lS_ flv oh P-lfe 1 poif _ shy11 IB kl (4 itlaquoT lamp llt0 oot^
mdash -n
It T1 |ir( L1 HI 2 0 oil
U 1M ft go C ICf^ -^2 Z laquo-|o
11 it 5 bulln - TO o abull Li u-i IT1 -- Iw O ltM (I bullbull bdquo-I(K 1mdash -tilltLlA ttfe
i Dgt ac -- U 44 4 11 1 1- ytd i i_i J-K 0 i if -i i i V t Wl raquoOHM 1-1 US D C P A R T M f N T OF COMMfRCE t 4 1 IUII 1 1 ^~) mdash
llaquo- Hi NC bull bullh bull bullJL^V HBl CO 00
11
)jLsVyr^gturv
^ | TKu
|-_t_ bull(
IIMgt I I Mt|UU III- II 11
PNECIPITATIOH
I 1 1 IMX
IMO
bull llfclaquo I UCIUKI) Ur C V A r U M A AHO CLIMATOUOCICAL OBitH
E V A F O R A T I C r i Jttffl laquo amp hMIlaquoJllaquoJIIlaquoBgt
DATE AOOITIOMAL DAIAKMAKk M
bullraquobullmdashlaquo
tp 01 (1 Of Ll OOI ooo
0^1 o-i 10 tl |00 102
OC (1 13 Ofl
it i rc DS os an
(1 SV o
Ul 010
(ISl 101 I on
130
II 5= Otl
ss lt 001 (IK Ml
jt il HIT
7 it
ow Wo 17 Top 2-01 OIO
(0 oov zi oot
u CO ^A 0 to Zoi CLflS
bull50 01 ljtj
nshy 5H LO OIt
50121 IVO QJO
14 Co Ho LO Hl ^pound Jl 1
ltM ool fllc
H Tl 01 II
11 11 Q1
iH OIO
HO 2 llaquol 11 II
lifc
IV-IIM ul OIPAITHINT or COHMIICC NOAA
NAtlOHAL gtIATnlaquoll raquotraquoVlClaquo CD
r~
All TCUMMATUNI ^V UII rgt ITmi 1 Cwphu Obic i gtn t ngir-H 30
rilCiriTATIOH
JJ T I rTJ-rimdashr-iramj|MP CLmATOLOQ
laquolaquo jftilCiii bullIHO
Oi1l ADOITIOHAL DAIAlllu
Ilf4ft
Sii1
(1 2 IO OO
Hl ii SO
us OIM
Q^L
a A3 Hi SZ Sf^ bull 12J2
HI Z-SF OOl 1C t HM IA H ICP fiJA
OOl 10 (310 sn 310
if HI (0 ^01
bullit SO 28H poundJ1 11 006
14 35 TX oon II (bull2 it zr II c-S
rr Zll lo 31 OP an 31 a 31 oor
CSW O-ll Si CC Of 011
Oll _ I |ft
00
u i oerraquolaquoTMiMr of c NOAA
NATIONAL K C A T N C M SCMVlCC
TC^S lk)oiVroTJA
TETT I 7X
1raquolaquolaquo 4 bdquo ir lt er ni I^OV ltqgl j--^ TQ
MICiriTAllOH ITIND
D|mdash
b5NO ctiUATOtoiCAL oeit^
OATI AOOITIOMAL OATAVlHAtt
0-tt
Mlaquoh bullbullbull- rshy laquo
I- ltltriu HI I 4 bulllaquobullbull1
Zii
30 Dfellt otvt
at HA
OOI
62
iJ_S2 HI if
bull- 20 SI 2i So
So
VVfr
OSfc
I (
Jtlt
3aoi
r j -bull ie MA
Irill iiol
in^ 14
Mo
Zll
214
21 1P
00-i
bulliron
17
bullr
11 i ir- I J Ktf^c
US D E P A R T M E N T OF COuMEDCC I | C gt A A
K AIlaquo Ttupf lATuit r
|SlVi AlJ PIICIPITATION
oJud (El
VIM i Uraquo
MIND E
EVAPORATIOH flnrft bull A ftufiifccdll
KECORO OF eVAPllHAtlil bull I CLIHATOLOOCAL OBSERVA ^Hij
14 MM A_M AOOIIIONAL DATA11 MAIM
Mr bullH Oo|
M Si lift
bull221 IHI
ZS Ji 40 IZV
icr KS I
HZ 111
bullT 21
loA UK JA IP
v^ ft
1M 2Sshy IT Tl
71 V |
i I 31 1deg a
uty^ U bull3
ons 1 CiO TxX
HHO (10
3H 19 12 10 IP
raquo3H raquo | 5t io
OP OIT
14
vO UI Of PANTMINI Or COMMCRCf MM O A A
F ngt TIHH
iiicffwiffc 4 rJ (TIM bull Cempltit Obitittiio
AIlaquo TIMHIATUM PHICinTATION I V A f OK ATlPrl
OATI ADDITIONAL DATA KMAlIt
U4laquo4 +
03H Ji
10
rc a 1 16 oi ii
tiiy 10
OI
II i23 or o 13 -y~ou HO
II 3V III i 3 t
V laquop oot
OM1 SS ne
T an -i IP
Olt zr LTV
3T 001
a -11 2T
10 an 31
-1 raquo 131 UP 3H lf 14 Lpoundshy
it 14 30
IS
Ui O I P A K T M f H T OP COWlf ICfM O A A
NATJONAI V C A T M C n f t K M V l C K
bullbullbullbullbullshy -2 o AIlaquo TIMMRATUM f fKICIPITATIOH
OATI poundt- MMINMAL DATAk
ZP 51 lo icr
011 111
OoT IHf
Ut 003 am
3o 13 ao
4A X 05shy
H4 i IjJyiV131 ooc js
IH oi 01 tL 18 13 a
No 11-7
rivgtp OO| M Hi 03 01
It 12
bull I 41 bull7119 14 ^^ raquo 31 15 lampk n M ho i
Jo -j-
-J
I
Ml H^ I _
amp2ampUi^= LS 0 S 0-f bullTTT
-Vmdash gt U_ bull 1 rOHM I- 11 OI OCPARTMlNT OF COMM(NCC
HO NATIONAL W f A T M f H ftfraquoVlCI
98
Appendix B
Boring Logs
99
X iHECT 1 ff 2
OAT American Drilling amp Bor ini I Co Inc
wo WATH smn EAST PR ov IDENC E ft 1 Town of South Kingstown South K ngstown R I MOLENO X-J
TC 100 RCSS bull ujrMonitorinq Well Installation | South Kinqjtown R I UNC a STA Pf KXICCTHJ LOC ATK3N
bull cfrserrr TO above S MPLES S FNTTO _ _ |laquolaquor A-109 SURF ELEV RE PORTSEr
GROUND WATER O6SE RVATC MS 1 CDREraquolaquo m-T nn75 laquo A 256 - 20 mdash Hew y
Instolled 32ofT-l2 PV C - JO- COMPUTE 111275 K toia 3- I-WI 1-38 TOTAL MRS bdquo10 screen BORING FCACUAM J K lanq MAI rraquo HomnwWI 300 140 IampPCCrc Mamlaquor Fall 24 30 lampaaiona SOLS ENGR
LOCATION OF BORING H ONITOKING WELL
Coung Samplt Tjp Blow per 6 Manure SOU IDENTIFICATION Strata SAMPLE ^^^yV Bloot
foot
Otptni
From- To
el
l
on Sampler
0-6 1 -6-13 12-18
Dentity or
Conmt j
Chang Remark include colo^ graaation Type of tod lie Rao-coMr type condition nordshynetiDntotf time leamt and tie No Pen Rtlt
2 No top sample 5 12
1 loamy fine sand
bull)^ 40 30 36
5- 616 0 23 20 16
noist iense
Brown fine to coarse SAND some fine to coarse gravel Trace silt
^
1 18 18
36 8-0shy57 40 30 V 35
|0-||-6 D 14 24 20 Srown medium to coarse SAND Some fine gravel cobbles
7 IRshy 16
27 75 37 3
IS- I- D 5 14 16 3bull
ISshy 15
42 50 I9--0shy50 65 20-2ll-6 D 9 23 26 bull Jrown fine to coarse SAND Tbullwshy 1Z 75 90
22-0 Trace silt trace fine gravel
124 120 74 60 52 41
7S-ltlaquoil-A DX 71 16 13 wet very dense
Gray-brown fine to coarse SANC Some fine to coarse gravel little silt
H IR u
40 30--0
3C-30-IO
3l4-334
334-3314
38 4-434
D
c
C
C
7 IflO
94 6
we tr j
y se
ft irox
30MOshy
31 -4shy
Gray-brown fine to coarse SAND Trace silt
Gray-brown fine SAND some lilt trace fine gravel
Too of Rock 31 -4shy
Gray-pink GRANITE
6 7
amp
CJ
IltJ A
60
601
IQ mdash
2(
4
5 i Hard
ft 5ome seams bull
GROUND SURFACE TO J 4 U3CD_ ^JVrf bullbull( tutu t to 4o 4 SampM Type Proportion UMd MOB Wtx 3 OfaM on 2OD Sampler SUMMARY-
OOry CCartd WltWen4 Hoc OlolO Canmonieraquoi Don any CoKeem CarMWncy Earm Barrlaquoj 11 14
UPgtUnOigtturod Piuon trite (Oto20dego 0-Kgt Loei it 0-4 Sait 3O+Hofd Rock Corng 14 Kgt-30 laquo4 0 rte 4-8 MSHM Samplet TPTtitPit Ai Auger Vvanefett tarn 2Olo39 3O-M Owlt n laquo-lS Strlf rinit nn v 1
UTiUndlshffbed ThrMOll and bull 33to9O 5O Very 0laquo nraquoe 19-30 V-3trraquof - | OLE NO X-l
TOVH rim - iA it raquotoraquo
100
SHEET 2 o_L
WO WATEt STUET [AST ft OVIDENC pound a i American Drilling amp Bor ing Co Inc
MCLl WQ X- 1 Tt AOORCSS i
LIME A STA KXICCTMJ tuf same as 1 | tame as i LOCATION
W PORTSEf mo OB nj urt eflaquo T
illtPLES S
P
CVTTO nlaquo mun orv
^s f^ Tin i GRCVMO WATER OBSERVATONS CASING SAMPLER CORE BAR
START Typi COMPUTE tome at 1 same aiH
TOTAL MRS BORIMG FOR CMAN n bull IT INSPECTOR SOILS EMM
LOCATION OF BORING u HfVJTneTfi UFI _
8
Counf Blo-t
foot
Dtpllo
From To
0( on SampMr
0-6 f 6-IZ
Moittir
Oonuty or
Contilt
Strata Ctnngc
SOIL OCNTiriCATION Rtmorkt ineHifl cotot grqdotion Typlaquo of Mil etc Roo-axtrPlaquo condition Mrdshynlaquot Drog tun ttomt end tic
SAMPLE
No Ptfl RfK
434-4o4 c
approx 7 minj
per toot 454
Gray pink GRANITE Hard Fairly solid core
lt_4 24
Bottom of Boring 45 -4
-
~
bull 1
GROUND Sorrow Tye
SURHCZ 10
bull OiOry CgtCord WWothod UPUnditiurMd Piston TPlaquoTtraquotPtt AtAuotr VVor
UTltUndinrvd TTMMO bull bulltat
iivnPilaquo(onioni Uraquot4
me OioiOItttt laquoraquo20
wmt Z0ie33
and 361090
c M
C1 5 Si
-SOshy
ASING
IOtgtWtigt bullnlot Dn 10 Loci M Mod 04 SO Dm 1shy Viry 0laquo
s _
TMEN 0 hMl on 200 SoiTBUr laquoity ConcMMt Conorawncy gtbull 0-4 Sort 30shym 4-B MStlfl M BH9 Strtf bull ts-so v-swt bull
t-HOrt Ear Bern RoetCorrt
i ^^^^^ bull
-[MOLE no x-i
101
raquoMEC rAmerican Drilling amp Bor in g Co Inc 1 ofj_ DATE wo WATlaquo smn UST Plaquo IOIDCNC j laquo i
Town of South Kingstown South Kingstown 8 MOLE MO Jlt Z TC rx MCS3
rtprr uAurMonitorina Well Initollation | South KinqitowrxRI UNC A STA P KATIOM ME POCT ^rwT TO above I OFFSZT
uD^r laquorlaquorTTO 6 -109 suw tLEv Sgt louffJOCNO
0 tj Tlmlaquo WOUND WATER 06SCRVATC US gtW Rsdl SING SAM^EH CORE BAH
26 ^_ 12 $TAlaquoT UL 2Z2i Ji r TTP NW ltA sr IJZC Z5 CCOMPLETE
SitLO 3 I-3B- 1-38 TOTAL MAS 41 BOAINO FOACMAN JK1 ana nf ni n MonwwWl 300^ 140 BIT bullK^CT
gttonvrar Foil J^laquo 30mdash Diamond SOOJIEMGM
IE HFII
iCaunq SampM Trplaquo BMMtpw6 UOIIIK- SOIL DCMTIFKATION Siraia SAUPLE Blow DlaquoPIAraquo of on SompMr HtmorU mcJuo cotes gradation Type of Dwuily
pw or CXang writK Roel-eolorlyp condition tvort-From- To Vfoot 0-6 f 6-2 12-18 Coniitt egt rwtiOnAngtimt wamaondtte No Praquon Rtlt
2 Brown fine SAND little silt 2 2-0shy5 15 18 moist Browi fin to coarse SAND 18 5- 6-6 0 14 25 27 vlaquo Troc fin aravel | 25 wy Ifl 11
dlt tns 35 40 38 moist n in-il-i Lgt U 15 18 ie is li1 Irl IS 31 I2-0
~~43 1
A) Jrown coars to medium SAI MD 48 moist Little fine to coarse gravel
|5-IA-Xlaquo 14 47 41 fn D laquo y Little silt rrqa coarse sane 3 18 I1
68 In IS 44 32 34
n ^n-^i-A- w 2o 19 29 wet 4 la -59 lens ltfO no
25-0 2amp bulllaquo- 77 c BOULDER r[ 4 i
27-0 5X ~W 24 24 bullWar- 5 Ifl irown tine to coarse SAND some
dens 29-0- Fine-coars gravel trace silt
30-3I oxx 30 32 30 moist irown -gray fine SANDiom e 6 l rr Vlaquoy 31 -0 silt trace fine oroveTILL
Bottom of Boring 31 -ampbull shyBent casing -pulled out and moved over 4 - washed amp tJrovlaquo casing to 30 -Installed 3C gtof 1-12- PVC - 10 screen
WOUND SUraquoraquofCE TO 3pound 1 yijfD MW t ASIMC TMCJ laquo olaquorod -bor of borina
SomoU T]Fplaquo ProigtuliOraquoH UMd MIOtgtWLx3Orolt lon2OASanlaquoMr SUUMARY-D=Dry CCorad Wlaquoworaquonraquod bullact OiaiO CanM gnMM Daonty CIMIH Caamraquoci EffW 8or^ 2pt
UPiUnairurMd Pition Itnt laquoM2O O- O UKraquolaquo 0-4 Soft 3O-hHard Roelaquo Corrig o- JO M0mlaquo 4-8 MSNff SOTipM 1 p^ 3O-9O OwgtM bull-IS Slid
TPlaquoTraquojraquoPit AAugtr ViVon mini tamt 20to39 UTtundiifir6d TrwMOtf and JSloSO 50-raquobull Vary 0nlaquo [HOLE NO x-2 B-3O V-3Mf lev rim - IAIT raquosectlaquoraquo
102
300 iu 24
1 UMnii ffi 140 laquo 30
CA1INC tf
gt taWCTf
bull 0gtlaquo i R Cook Jr_ R Millineton1 Wttn
I~
1 VAMtl CtMG
1 W HO-t MO
1 Oraquo 1 laquo0~ twt
L 1 laquo-raquo VfcM^lf [wlaquoraquoCI ^ ^ K3Ot III laquo
0-LS D
5-65 D
LlQ 10-115 D
15-16 Tgt
Lraquo 70-51 n
25-26 D
F
I O-O Ci
A Allstate Drill ins Co vi o i
PROVIDING R 1bull raquoraquo uvraquonn~ N M O M I T O P I N G HE1 _^lt -^ PI-Traquo UJU
CUM Town of South Kineraquotown raquoraquo 1 1TA maoer Propolaquolaquod Sit for Slude Disposal nltn
laquo V-449 iampAAtut i a 138 ort STI bull r 42777 CtOuMO IKVtllON
Cill bdquo 258 DA II MN ru 42777 rilaquolaquodO laquoraquoTti rum 1911
AU1TATI
MMUI1 raquolaquogtlaquolaquo laquoKiO itXHHKraquoriOi of sous MUAHI nMTKlion Ot CMlaquoMC|kOraquort tl CO~VH DXltgt raquomlaquo laquotf IMi COIOI C4l II I 1raquo gtlaquo^ Oraquo 1Ol rC t Xgttgt VtfKOe Craquo Mi 1 ft liMraquoK laquo0^tlaquot nfgt
1-2-1 10 TOP SOIL FINE LIGHT BROWN SAND traclaquo of ilt
16-31-17
22-24-21 100 FINE TO MEDIUM LIGHT GRAY SAND trace of fine gravlaquol and raquopoundLt
lfl-37-34 150 LIGHT BROWN FINE TO MEDIUM SAND little poundinlaquo gravel
21-17-15 200 MEDIUM TO COARSE SAND bullomc fine gravel
12-4-10
265
Observation well installed
NOTE No casing blows taktn
bullbull B-23 ow
^w^ 265 I raquo bull raquolaquo bull I W
11 laquot gtbullraquo Vlaquo 14 W gt_ c-shyji bull alaquo bull jraquo VI laquoHshyw bullbull m raquobullbull D-6 raquo Mshy
bull bull laquo Vshy
1
bull bull
I
103
MAMMII Allstate Drilling Co ulaquorr 1 or 1 FftOVIOCKZ H L traquolS mTArm^S MONITOR NR WEL
VNO wr3JJO__raquoraquou_24__ HCU MO P-74 n iu riBwi Town of Slt7H^ Xirpin
mdash^ laquo0J P 1 1 bull ^n^ciit^o TVlaquow^laquott1 bullraquoit wt 140 nu 30 olaquor fBu lkv Waste Disposal Arcai
MUTAH a V-449 R Cook Jr UMlaquoiigti D 1 38 0t| raquoIJ raquo 5277 rlaquo SUMO luvlaquorv-laquow
mdash 5277 fipe -raquoT pfpm 150
H MCIO IMNTlXAflON Of SOU t(kAIlaquoS rrn 0-laquoraquo
5 -SF 01 w in laquobull -raquo ^ lit
D 1-2-2 TOP SOIL V-1-oraquo
15 IPbull FINE TO MEDIUM LIGHT GRAY SAND AND GRAVEL
5-65 D 37-27-35 some silt
10-11 D 20-14-18
15-165 D i 17-14-14 155
BROWN COARSE TO MEDIUM SAND little fine to coarse gravel trace of silt
20-211 D 4-4-2
230 GRAY BROWN VERY FINE SAND
25-26J D 7-8-9 AND SILT 265 fvarvedl
Observation well installed
NOTE No casing blows taken
wta 10 n uuraquo c^imdashbull IgtM laquolaquobull- B-24 ow ~ 14 ltfc laquoraquobull vlaquo^ M laquobull r O 0 fmtt bull W-L 26 5
-0- CgtCmdashgt bull laquolaquobull mdash laquo 1 - raquoraquo 1 gt 1laquo bull 1 gtraquor to bull mdashbull bull bull bulllaquo I t l~laquo 1lt Uraquo mdashbull ) bull 1 gtbull ft 0~ H laquoy bullM ta bull -IN la laquobull OPUM bull($ IMI
mdash H raquo laquo-bull
104
Appendix C
Calibration of Specific Conductance Meters
105
Specific conductance measurements were made using a beckman RB
338 temperature compensating meter and a YSI rtooel 33 salinity
conductivity temperature meter The YSI meter is not
temperature correcting A formula to compensate for temperature
differences to standardize YSI measurements was used (21)
A long probe for the Beckman meter was used to measure conductivity
in the wells Differences in conductivity between the YSI ana
Beckman meters and the Beckman short and long probes exist These
were calibrated in the laboratory using 001 N and 01 N KC1
solutions Values presented are Beckman short probe values The
Beckman long probe values were reduced by 76 and tne YSI values
were multiplied by 11 to adjust to Beckman short probe values The
YSI meter was used in the latter phases of the study for the
stream contamination due to the greater accuracy of the dial readout
scale
Table 7 Specific Conductance Meter Calibration Table
Concentration (KCL) 0001N 001N
Specific Beckman short 145 143 143 1247 1245 12GO
Conductances Beckman long 190 191 188 1639 1650 1665
umhocm 9 25 C YSI 132 131 128 1131 1140 1150
average values Beckman shortBeckman long = 075
Beckman shortYSI = 11
106
Appendix D
Computer program Flow Chart
107
F1g 33 Computer Program Flow Chart-
1TpoundR MAP TCO
NEWPER
WEWSTP CZAX
HEWIT TRANS TCOF ROW COLUMN
Yes
Yes
108 The following is a description of the USGS two-dimensional computer
program Iterative Digital Model for Aquifer Evaluation updated
December 1972 by P C Trescott The program written in Fortran
consists of a MAIN program and six subprograms or subroutines which
themselves are organized into subprogram sections The subroutines and
their sections are listed below
MAIN Program
DATAIN (subroutine) COEF ITER (section) CLAY MAP TRANS NEWPER TCOF
ETRATE COMPUT STORAG
NEWSTP LEAKAG NEWIT1 NEWITO CHECK ROW CWRITE COLUMN STEADY PRNTA OUTPUT DRY BLOCK DATA
The program begins in the MAIN program which controls the sequence
of passage to the subroutines Sequential steps are described in the
program as shown in the flow chart of Fig 32 Emphasis is placed on the
steady state confined aquifer case as applied in this study First data
input is read in the DATAIN subroutine This data includes transmissivities
or permeabilities starting heads storage coefficients and grid spacings
Nodal transmissivity values are then computed for the water-table problem
in the TRANS section (COEF subroutine) This procedure is necessary here
because the subsequent routine for computing iteration parameters (ITER)
keys on nodal transmissivity values which would not have been input to
the water-table problem In the water-table option these would have been
109
computed from given bedrock and water-table elevations to obtain the
saturated thickness component of the transmissivity calculation In this
study water-table option was not used and the transmissivity values were
input directly The program then passes to the ITER section (DATAIN
subroutine) to compute the iteration parameters which expediate or even
cause convergence Next the MAP section (DATAIN subroutine) is utilized
to initialize data for an alphanumeric map if this was requested in the
input options Transmissivities are then computed for the confined
(artesian) aquifer case (water table not specified with input options)
in the TCOF section (COEF subroutine) These coefficients are harmonic
mean values of adjacent nodal transmissivities weighted by grid sizes
Time parameters and pumping data for a new pumping period are then read
in the NEWPER section (DATAIN subroutine) followed by entry into the
NEWSTP section (COMPUT subroutine) which calculates the size of the
time step Leakage coefficients (hydraulic conductivity of the confining
bed divided by confining bed thickness) are next computed in the CLAY
section (COEF subroutine) if leakage was specified in the input data
which was used in this study
A new iteration is then initiated in sections NEWITO (COMPUT
subroutine) NEWITO saves the current head values and compares them to
the updated head values for determining closure This is followed by
nodal transmissivity values being computed for the water table or water-
table artesian conversion problem Transmissivity coefficients are then
computed for the water-table problem in TCOF (COEF subroutine) Total
head values are then computed with the alternating direction implicit
procedure using the Thomas algorithim first along rows in the ROW section
110 and then along columns in the COLUMN section both in the COMPUT subroutine
Then if a solution is not obtained (because the error criteria for
closure is not satisfied) the MAIN program branches back to NEWIT1 subshy
sequent sections TRANS TCOF ROW and COLUMN repeatedly until a
solution at the particular time step is achieved NEWIT1 increments the
iteration counter and is immediately followed by NEWITO The program then
moves to the STEADY section of the COMPUT subroutine to check if the
closure criteria for steady state has been satisfied Output is then
printed in the OUTPUT section of COMPUT if steady state has been reached
or if the particular time step is designated for output
The program then branches back to NEWSTP (COMPUT subroutine) and
moves through the subsequent routines until the last time step in the
pumping period is reached Output is then promoted in the DRY section
of COMPUT if specified in input data If the last pumping period in
the problem has not been reached the program branches back to the
NEWPER section and moves again through subsequent sections otherwise
the program will terminate or start a new problem if one follows
This study was simulated as a steady state problem which can be
simulated by setting the storage coefficient of the aquifer and the
specific storage of the confining bed to zero and using one time step
of any length
111
Appendix E
Computer Data Sheets
RGSEA
10 ROSE HILL LANDFILL MODEL 20 30 40 LEAKAGE 50 60 70 CHECK 80 90 100 HEAD 110 120 1 23 IQ 100 5 001 37E-OU 0 130 100 001 0 0 1 4 0 - 1 - 1 1 - 1 - 1 i i i i i i 1
ISO 1 10 0 1547E-05 01 10 1 1 160 04642 200 200 1 1 i it
1QO 190
CARDS I THROUGH 19 - CODING SHEET
CHEAD
100 110 120 130 131 132 140 141 142 150 151 152 160 161 162 163 164 165 170 171 172 173 174 175 176 177 178 179 1BO 101 190 191 192
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 539
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 58
25
25
25
25
25
25 621
25
25
25
25
25 662
25 25
25
CARD SET 2 - STARTING HEAD MATRIX (FT)
193 194 IVb 196 197 190 200 201 202 210 211 212 220 221 222 223 bull 224 225 230 231 232 233 234 235 236 237 23B 239 240 241 250 251 252 253 254 255
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 23 25 25 25 25 25
25 25 - 25 25 25 25 25 25 25 25 25- 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 - 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25
25 25
25
25 25
25 25
25 25
25
25 25
25
25 25
25
25
25
25 25
25 25
25
25 25
25 25
25 25
25
25
25 25
25
25 25
CARD SET 2 - STARTING HEAD MATRIX (FT) - continued
STORC 1512 FRI 19 FEB 82
100 110 -1 -1 - 1 - 1 0 0 120 130 140 ISO 160 170 100 190 200 210 220 230 240 230 251 260 261 262 263 270 271
CARD SET 3 - STORAGE COEFFICENT
LEAK
100 110 120 02 130 _ 18 02
I ltu 18140 025 150 02015015015 19 deg25
02 160 022 bull-laquo- J1 5 j 1 z laquo- l^
170 015 180 016 laquo02
190 016 OE025
200 02504019022021025 2 5 i S lt03 0252i2 n
230 030 deg23 deg2 deg2 deg2 -02023023 240 022 250 022025025 02
027043 013025
30() 025025025 310 025031 320 024025
CARD SET 5 - AREA OF STEAMBEDAREA OF NODE
120
Appendix F
Bibliography
121 BIBLIOGRAPHY
1 Agpar MA and 0 Langmuir Ground-Water Pollution Potential of a Landfill Above tne Water Table Groundwater V 9 No 6 1971 pp 76-96
2 Allen William B Hahn GW and RA Brackley Availability of Ground Water Upper Pawcatuck River Basin Rhode Island USGS US Government Printing-office GS 66-624 19bb
3 Annual Book of ASTM Standards Part 31 Open Channel Flow Measurement of Water and Waste Water by Weirs D 2034-68 1975
4 Annual Book of ASTM Standards Part 19 Infiltration Rate of Soils in Field Using Double-Ring Infiltrameters D 3385-75 1975
5 Baeaecner MJ and W BacK Hyarogeological Processes and Chemical Reactions of a Landfill Ground Water V 17 no 5 1979 pp 429-437
6 Beck WW Dunn AL and Grover H Emrich Leachate Quality Improvements After Top Sealing1 8th SHwRD MERL Symposium 1982
7 Beckman WK Transient Modeling For Estimating Sustained Aauifer Yield master thesis presented to the University of Rhode Island Kingston RI 1978
8 Bhattacharya PK and HP Patra Direct Current Geoelectric Sounding Elsevier Publishing Co New York 1968 135 p
9 Bouwer H Ground Water Hydrology McGraw-Hill Book Co New Yoric 1978 p 378
10 Braids 0 Cocozza pound Fenn D Isbister J Rous P and B Yarc Procedures Manual for Ground Water Monitoring at Solid Waste Disposal Facilities Environmental Protection Agency530SW-611 Cincinnati Ohio 1977
11 Cartwright K and MR McComas Geophysical Surveys in the Vicinity of Sanitary Landfills in Northeastern Illinois Groundwater V 6 no 5 1968 pp 23-30
12 Cartwright K and Fd Sherman Jr Electrical Earth Resistivity Surveying in Landfill Investigations Reprinted from Proceedings of ohe lOtn Annual Engineering and Soils Engineering Symposium Moscow Idaho 1972
122 13 Clark TP Survey of Ground-Water Protection Methods for
Illinois Landfills Groundwater V 13 no 4 1975 pp 321-331
14 Dunne T and LB Leapold Water in Environmental Planning WH Freeman and Company San Francisco 1978
15 Faro DG Upgrading Hazardous Waste Disposal Sites Remedial Approaches US Environmental Protection Agency500SW-677 Cincinnati Onio 1978
16 Fenn DG Hanley KJ and TV Degeare Use of the Water Balance Method for Predicting Leachate Generation From Solia Waste Disposal Sites US Environmental Protection Agency530SW-lfa8 Cincinnati Ohio 1975
17 Geisser 0 An Electric Analog and Digital Computer Model of the Chipuxet Ground Water^ Aquifer Kingston Rhode Island master thesis presented to the University of Rhode Island Kingston RI 1975
18 Hahn GW Groundwater Map of the Narragansett Pier Quadrangle Rhode Island Rhode Island Water Resources Coordinating Board GWM 5 1959
19 Hemsley William T Koster C Wallace Remedial Technique of Controlling and Treating Low Volume Leachate Discharge USEPA National Conference on Management of Uncontrolled Hazardous Waste Sites Oct 1980
20 Hughes GM RA Landon and RN Farvolden Hydrogeology of Solid Waste Disposal Sites in Northeastern Illinois Final Report to US Environmental Protection Agency PUD SW-l^d Cincinnati Ohio 1971
21 Keller GV and FC Frischknecht Electrical Methods in Geophysical Prospecting Pergamon Press New YorK NY 19bb
22 Kelly WE West Kingston Landfill An Evaluation of Its Effect on Ground-Water Quality Rnoae Island Water Resources Board Water Information Series Report 1975
23 Kelly WE Geoelectric Sounding for Delineating Ground-Water Contamination Groundwater V 14 No 1 1976 pp fa-10
24 Kelly WE Ground-Water Pollution Near a Landfill ASCE Environmental Engineering Division Journal V 10 No EE6 Dec 19b pp nay-nyy
25 Kelly WE personal communication January 1982
123
26 Kelly WE and OW Urish A Study of the Effects of Salt Storage Practices on Surface ana Ground Water Quality in Rhode Island NTIS FHWA-RI-RD-8001 1981 54 p
27 Kimmel GE and OC Braids Leachate Plumes in a Highly Permeable Aauifer Groundwater y 12 no 6 1974 pp 388-393
28 Klefstaa G Senalein LVA ana RC Palmauist Limitations of the Electrical Resistivity Method in Landfill Investigations Groundwater V 13 No 5 1975 pp 418-427
29 Landon RA Application of Hydrogeology to the Selection of Refuse Disposal Sites Groundwater V 7 no b 19b9 pp 9-13
30 Lang SM Bierschenk WH ana WB Allen 1960 Hyaraulic Characteristics of Glacial Outwash in Rhode Island Rhode Islana Water Resources Coordinating Board Bulletin No 3
31 LeGrand HE Patterns of Contaminated Zones of Water in the Ground Water Resources Research v 1 No 1 1965
32 Palmauist R and L Sendlein The Configuration of Contamination Enclaves from Refuse Disposal Sites on Floodplains Grouna Water v 13 no 2 1975 pp 167-181
33 Pinder GF A Digital Model for Aauifer Evaluation Techniaues of Water Resources Investigations of the US Geological Survey Bk 7 Cl 1970
34 Purushattam D Tamxe GR and CM Stoffel Leachate Production at Sanitary Landfill Sites ASCE Environmental Engineering Division Journal V 103 no EE 6 Dec1977 pp 981-988
35 Remson I Fungaroli AA ana AW Lawrence Water Movement in an Unsaturated Sanitary Landfill ASCE Sanitary Engineering Division Journal v 94 no SA2 April1968 pp 307-316
36 Rosenshien JS Gouthier JB and WB Allen Hydrologic Characteristics and Sustained Yield of Principal Ground-Water Units Potowamut-Wickford Area Rhoae Island USGS US Government Printing Office GS 67-324 1968
37 Roux PH and B Vincent Electrical Resistivity Evaluations At Solid Waste Disposal Facilities US Environmental Protection Agency SW-729 Cincinnati Ohio 1978
124
38 Salvato JA Wi lk ie WG and BE Mead Sanitary Landfill Leaching Prevention and Control Water Pollution Control Federation Journal v 43 no 10 Oct 1971 pp 2084-2100
39 Sawyer CN and PL McCarty Chemistry for Environmental Engineering McGraw Hill 1978
40 Stellar RL and P Roux Earth Resist ivi ty Surveys - A Method for Defining Ground-Water Contamination Ground Water v 13 no 2 1975 pp 145-150
41 Todd OK Ground Water Hydrology John Wi ley and Sons Inc New York 1959
42 Tolman AL Ballestero AP Beck WW and GH Emrich Guidance Mannual For Minimizing Pollution From Waste Disposal Sites US Environmental Protection Agency-500SW-677 Cincinnati Ohio 1978
43 Trescott PC Iterative Digital Model for Aauifer Evaluation US Geological Survey Open file report 1972
44 University of Rhode Island Academic Computer Center CalComp Contouring Manual
45 Warner DL Preliminary Field Studies Using Earth Resistivity Measurements for Delineating Zones of Contaminated Ground Water Groundwater v 7 1969 pp 9-16
46 White EF A Report to the Town of S Kingstown Utility Survey Engineering Corp 1967
47 Zohdy AAR A Computer Program for the Calculation of Schlumberger Sounding Curves Over Horizontally Layered Media Using the Method of Convolution US Geological Survey Denver
48 Zohdy AAR Eaton GP and DR Mabey Application of Surface Geophysics to Ground-Water Investigations Technidues of Water-Resources Investigations of the US Geological Survey Book 2 Chapter 01 Washington US Government Printing Office 2401-02543 1974
8
from the source and parallel to ground-water flow lines Other
parameters which control the extent of the contaminant plume are
dilution and dispersion in the aquifer and the adsorption properties
of the aauifer material (31)
The amount of leachate generated depends largely on the amount
of water that infiltrates through the landfill to increase tne water
content of the refuse in the landfill The precipitation recharge
that percolates down through the unsaturated zone to the water table
moves in a vertical direction (35) Surface runoff soil moisture
storage losses and evapotranspiration account for tne precipitation
that is not transmitted tnrough the unsaturated zone of aeration
(3315) Upon reaching the saturated zone the water enters the
ground-water flow system Ground-water mounding has been reported
in landfills due to the decreased hydraulic conductivity of
compacted refuse relative to surrounding aauifer material (20)
Chemical processes within the landfill leachate outflow and
surrounding soil cation exchange capacity relative to water duality
of the surrounding aduifer have been studied in Pennsylvania (1) anu
in Delaware (5) A procedures manual for ground-water monitoring at
solid waste disposal facilities was developed by the US
Environmental Protection Agency (USEPA) (9)
Several reports have been written that investigate site
selection design criteria and remedial measures to correct
leachate problems (29) A survey of ground-water protection methods
for landfills in Illinois studies relationships to the water table
theory of liner installation and monitoring devices (13) Sanitary
Landfi11-Leaching Prevention and Control presents a review of
preventative methods such as means to minimize infiltration
interception of ground-water and other pollution control measures
(2 37) A study in Pennsylvania on actual measures implemented to
collect and treat a landfills leachate discharge presents a site
specific study (19) Leachate Quality Improvements After Top
Sealing1 shows that by minimizing infiltration at a landfill in
Connecticut the outflow leachate water quality can be improved
dramatically and contamination plume reduced significantly (6) The
most comprehensive reports on remedial approaches to upgrading waste
disposal sites and ground-water protection methods have been
compiled under USEPA contract (1542)
To assist in evaluating remedial measures the US Geological
Survey (USGS) computer model Iterative Digital Model for Aduifer
Evaluation was used It was originally developed as a model for
simulating two-dimensional aauifer problems (33) It had been
updated since its original development to accomodate different
options (43) This model has been applied to glacial outwash
regions in Rhode Island (717)
10
Description of Study Area
A map of tne landfill area (Fig Z) was obtained from tne town
of South Kingstown The excavation to the west of Rose Hill Roaa
the landfill area directly to the east and the presently operating
area to the east of the central stream comprise tne overall study
area This study will concentrate on the west landfill area whicn
has recently reached capacity and been closed to further dumping
This site received mixed refuse for the past 15 years The depth of
the excavation where the landfill presently exists was approximately
to bedrock in some places Tne exact depths of landfill material is
unknown
The landfill cover has been graded and sloped generally eastward
to convey surface runoff to the eastern side A sandy soil that was
excavated locally was used as tne cover material The northern
section has a vegetation cover and the recently filled southern
section has been seeded and mulched The six monitoring wells W
NW NE EC SE SC were placed by the town of South Kingstown to
provide water quality information
Referring to Fig 2 the west excavation stream drains the area
created by the excavation to the west of Rose Hill Road and flows
throughout the year The central stream drains a small watershed
area which lies to the northwest of the landfill and drys up during
part of the year These streams flow into the Saugatucket River
which flows throughout the year and is larger than the west and
central streams combined
11
The USGS Groundwater Map (18) was initially consulted to proviae
information on the ground-water flow patterns (Fig 5) and the
geology of tne area (Fig 6) The surficial geology borings and the
vertical geologic cross-section at the base of the study area
indicate shallow water table and bedrocic and a nearly constant
saturated thickness (18) Boring logs at the W well ana a point
approximately 150 feet south of it indicate glacial outwasn material
which is primarily sana with a trace of gravel over bedrock at a
depth of approximately 33 feet Borings at the east landfill area N
and S monitoring wells indicate the same aquifer material
(Appendix B)
The ground-water map developed by Hahn is taken as
representative of conditions existing prior to the excavation of the
I l andfill (18) This indicates water-table contour lines that run in i
a general northeasterly direction This means tnat flow was
originally in a southeasterly direction However contamination of
domestic supply wells on the west side of Rose Hill Road has
occurred (Fig 3) strongly suggesting that the original flow pattern
has been altered by the excavation to the west of Rose Hill Road and
the landfill to the east of it Domestic supply wells were formerly
located directly to the west of Rose Hill Road but were aoandoned
when they became contaminated from landfill leachate New wells
were located to the south and west away from the contaminant plume
of tne landfill In addition a well located at the northeastern
corner of the landfill was contaminated and a replacement located to
the east of Us former location on tne opposite side of the central
12
Legend scale 124000
mdash-40 mdashground-water contour elevation
Fig 5 Ground-Water Map
13
Legend feet
TILL
Fig 6 Geology Background Map
14
stream This second wel 1 also became contaminated Domestic supply
wells located near tne northwestern corner of tne landfill and
approximately 300 feet south of it nave remained uncontaminated
These well locations serve as an indication of tne extent of the
landfill contamination which is largely dependent on the groundwater
flow patterns To furtner investigate this problem and provide
substantial information on which to base the geohydrologic analysis
field studies of the area were conducted
15
Field Studies ana Procedures
A map of the lanafill and an aerial pnotograph of the area were
obtained A tracing of these maps superimposed upon another
delineates stream landfill and monitor well locations (Fig 2)
The field investigation concentrated on the west landfill area ana
its aajoining streams ana monitor wells The east landfill area and
the three monitor wells in that area are induced in the latter
phase of the study in oraer to expand the model area
A traverse which establishea tne monitor well elevations was run
using a Carl Zeiss level These were originally sitea in by the
town of South Kingstown using a local USGS reference datum number 40
(18) The wells of known elevations then served as benchmarks for
referencing adjacent stream elevations This in combination with
the depth to water table measurements at each well enables tne
water-table surface geometry of the area to oe visualized
Water-table measurements of the west landfills wells were recordea
over a ten month period to record fluctuations (Fig 7 Table 1)
The east landfill areas wells were monitored for a five month
period Using a given water-table condition a ground-water map was
developea of the area (Fig 4) This indicates an outflow from
the landfill primarily in a southeasterly direction and partially
in a southwesterly direction
Additional bedrock and water-table information was ootainea by a
seismic refraction survey at several locations along the landfill
perimeter A Bison Model lb70C Signal Enhancement Seismograpn was
used to maxe the surveys Lines were run (to a length of kOO feet)
16
17
w s p bdquo S bdquo s S S a laquolaquo _
s 2 8
V
r bdquo
3 s a
-R s
S
S 3
t
raquobullraquo
S
5
K
r
~
3
K
pound
7
S
bdquo3
C 5 S
shy raquo S s
1 3 s 3 2 5 ^ bull
5 m
s o
^ 3
raquo
--
R bull 5
s pound J O s
5 a 3 7 3 m
5 s a ^
iraquo a s rlaquo
M ^
^ c o 2 5 s 3 a S R
rd 3 y a O =J
^ bdquo
JJ s s 3 bull ~ I
~ s 5 3 a s a
(Ogt (U
2
-t =
r s s in
5 y
a s
5
3
s
5 a
^ a
3 a 51 a bullbull
sj 5 Ml
3 a bull
s raquo
a
0)
0
^ mdash
a j -
-3
C
g S
S
bull a
-
~ 3 o
2 s s 3 a bdquo s s $ Al s
(1) = $ s 3
S
c a a
3 e 5 s N s S a - 3 = s s a 5
a s s - 3 S shy
4
0
a s
bdquo tfH
bdquo
3 a
bdquo
s a
e bullfl s i s s a s a
3 nt
s s 3
g laquo s3 a
~ J s 2 a s o s S s 3 a a j laquo s o s
3 bull laquobull
2 a 7 3 a 3 a ^2
s mdash 5i o
bull bull
mdash
3 o
ss a
fc mdash
3 1-sect m ishy n
18
in both directions to provide a check and permit accurate estimates
of the depth to bedrockThe seismic results allow approximate
interpretations of the depth to the water table and bedrocK thus
permitting an estimation of the saturated thickness Ground
elevations at the location of the seismic surveys were determined
from a topographical map and field siting From this information
water table ana bedrock elevations estimates were made Bedrock
contours are listed in Fig 8 In addition a table which
summarizes the seismic refraction results for the unsaturated
saturated and bedrock layers velocities and depths at each survey
location is presented in Table 2
Scream gauging stations were established on the two streams
bordering the west landfill (Fig 9) Three stations were placed on
the central stream These provide information on the influent or
effluent condition of ground-water flow in the upper sections of the
stream and ground-water baseflow from an area adjacent to the
landfill into the stream (Table 3)
The stream gauging stations used were 90deg V-notch weirs The
weirs located in the SE and SW positions were placed in the
streamoea with a liner of plastic upstream to minimize underflow
The weirs located in the NW and E positions were cut to fit in
recesses of concrete culvert pipes Concrete plywooa interfaces
were coated with roofing cement to minimize bypass flow Upstream
water pressure and a snug fit hold the plywood sections in place
All weirs were implaceo according to AigtTM reouirements and flowrates
calculated using the standard 90deg V-notch formula (3)
19
N
seepage West observat ion Landfill hole
Area
Legend landfill limit excavat ion limit
copyWNWNEECSESC monitoring well locations
= = = unimproved road -- WNES-number
seismic refraction locations
-40shy approximate bedrock contpur elevation
feet
Fig8 Seismte Survey Location
20
c ^-^ c4j ^laquoc in -=r 3shyjj bull pn f- 4-gt bull in in OjJ bull bull a jo bull bull O JJ
co CM o on on CO CM CTNVO VO co CM o on on Q gt_x rH oj on a oj on a - rH oner
rmdash on sr i i
M z Z
gt gt gt
X-N CO laquomdashv CO CO bull igt gt bull
1 gt fc^gtgt bullbull ^ ^ ^
C 4-gt O t igt O J- 4J O H m o o o 3 bullH CO O rH in 3 bullH co vo o in 3 ~ 1 i-k -i ^trade fj rj ui ij o CO o n o rH =r co o n vo vo vo co o bullv O O O
O raquo On-3 rH O -bull- rH ON in _ IH in oj - rH bull rH VO OrH bull rH On ON pH d)u CO -UCO 4J OJ CO 4-gt gt
C mdashbull gt CM gt CM H-l O CO
v- ^^ N C 0
bull0 N CO
4-5 -0 _c^gt in in CO CO
C x~ c -^ t-oo in i 4J j_gt 41 4J bull 9 bull bull 4J bull
o j ON O O 3 (0 O4J O ON ON QJJ t~-^3- OJ 4-gt L
CO CM trade CO CM rH rH OJ co CM oj on Q ^ _ CO 3~Q-- n 45 Q mdash OJ OJ OJ C (0
1 11 3 nZ 2CO
gti gt gt CO CO CO ^-x m -s CO
rH rH ^ ro^^ bull gt bull ^ igt gt bullgt gtgt bull r O -Q 4Ji JJ O 5- JJ O pound- ^ O 4) oj o on (0 CO
3 bullH CJ O O in 3 bullH CO Cmdash VO on 3 pound-laquo H CO o n in inco co o n ma- r co g^ 5sect^ o
o rH on oj O bull- rH ONCO L O_ rH OJ VO M
rH bull rH =t rH bull - OJ T CO CO M CO 4-gt rH CO -U rH CO 4-) s
uits
CO 4-gt 4-5 T3 gt CM gt CM gt CM cc CO CO CO
3 3gt oa tlp^ CO O CM O gt 4J O 40 i 3 r+ k C pound JS
CO pound
^^ s -bullgt cmdash on poundZ VO CTI trx 4J 4J 4J
) bull bull bull Q Q Q Q4J 3shyc O-JJ CTgt OJ OJ Q-IJ inco on CO CO CO o co CM oj on co CM oj on co CM on
Q Q QON^ Q bullH Q^
rH rH 4J rH
O bullraquo L Z bull CO CO CO
i gtgt rH oj on gt tgtshyCM ^ cO^-s CO ~ CO
CO CO J X fc^_ bull^gt bullgtgt bull gt gtgt bull gt CO
j_ jJ O pound- Jj -P O Li deg =fObullH co on f- ^ 3bullH CO CO O in 3bullH CO
g^ -^2
poundsect HO
eis
mic
3 CO in in in in in in co o n co o n
o -^ r oj in O rHCO CO rH bullrH bull rH =T OrH bull rH OJ f-CO 4J bull- CO 4J rH O0) J-)
gt CM gt CM gt CM 4J
CO N_^ m^
bull OJ
t t poundshyCO CO CO CO rH J3 gt r-t oj on gt r-i oj on gt gt r n o j o n
lto co lto CO T bull ii-4 laquomdash bullmdashH
bullo CO L L 0)
CM CO cc
21
N
545-594
seepage observation
hole West Landfill
0NE I47-509
Area
Weir 45
i487-531
0 EC Al3-467
Legend bullmdash landfill limit -bull---excavation limit r-s stream
copy WNWNEECSESCSEN monitoring well locations
= = = unimproved road
Weir location and elevation
feet
Fig 9 Weir Locations and Wate r Level Ranges
22
JT NO
S shy S
O
bull ry m
oa
NO
(M raquo 1 03 or NO m
JT O O raquo
O NO 03 (j
PW tn in ^4 fraquo
m CN) f O O (M Oj
mdashraquo 3 M
s cshy -raquoraquo
o in in ^
rjO
laquobull NO ON
o bull-lt ^
H fy (NJ
tjgt
1 4 03 O
o
o
03 CM
in0
0
7 raquo
9gt
IM i iev NO
i in
i ru
i 0 rsi -or^
sO NO
CO O
03 raquo
1 O3
pound o ro CNJ
03
tn B OJ
o 03
m oi
NO
(M
r
(M
CO i M 03
m N ltn ~+ ltM -
QJrH
O M O ^ ^r-
oo m
8 a
m
^ NO
8 fNl
rshy03n
m - in
o laquoO
bull3 as m o 03 03 4
i O
i ^
shy
O
ltM bull^
ON f tn H 1 4 raquo4 i-4 H P-t
^^ lt-l
r-laquo
^ 1 1 1 1
pound raquoraquo O)t o gtz
bull bull ltbull
lt2
1 pound OJ
3 oi g bull
pound
1 pound laquolt bull
3 bull o a
pound
5 laquo15
f bull 3 Jl s
5bull 1 5
23
A field study to determine the infiltration capacity of a
section of tne landfill topcover was conaucted A modified version
of a double ring infiltrometer was used to study infiltration rates
(4) The cylinder diameters useo in this study were 8 inches and 18
inches A constant head of 6 in was maintained in the
infiltrometer and rates of infiltration were determined Tnese
results and an analysis of surface infiltration into the landfill
are included in tne analysis and discussion section
Specific conductance levels in the monitoring wells in the
streams bordering the landfill and at observation holes near the
landfill were measured (Fig 10) This is a good indication of the
mineralization of water (39) Specific conductances were measured
intermittently over the ten month period to develop a picture of the
extent and degree of contamination in the wells (Fig 11 Taole4j
and in the surface contamination monitoring locations (Fig 11
Table 5) A comparative standardization of the Beckman (short and
long probes) and YSI specific conductances is in Appendix C
A surface electrical sounding using the Schlumberger array was
conducted adjacent to Rose Hill Road at the R-l location (Fig 12)
in an attempt to delineate the vertical extent of the contamination
zone Well W was used as a centerpoint and a reference for
water-table depth pore water conductivity and depth to bedrock A
Schlumberger array electrical resistivity sounding was also
conducted in an uncontaminated area at tne R-2 location (Fig 12) to
provide a comparison background interpretation A seismic
refraction survey N-4 was conducted at the same location (Fig 8J to
24
N
excavat ion
Seepage West observat ion Landfill hole
Area
Stream 1 Seasonal observation 0 EC
hole
East Stream2
Legend sw Weir landfill limit j--1--^ excavation limit
copyWNWNEECSESC monitoring well locations
== unimproved road
feet
Fig 10 Surface Contamination Monitoring Locations
25
8000T
7000
O bull U) W6000
Legend
0 sc A NE O W
A SE O N W
a EC
1 O N D J F M M
Time months Flg11 Flucuatlon In Specific Conductance in Wells
26
Table 4 Specific Conductances in Wells (pmhoscm at 25degC)
West East Landfill Landfill
Date NW NE EG SE W SC N E S
81581 851 938 236 2356
102981 171 3268
11381 3268
111081 304 988 1100 258 3800
111481 426 2736 1216 186 4560
111781 304 3610 433 389 4560
121981 380 1406 129 103 380
1982 160 152
31582 274 760 1064 61 334 8000+ 182 53 84
52182 450 1500 1125 112 712 8000+ 175 255 150
52282 425 1320 1200 110 850 180 320 170
27
O
ct c r i c o o o o o c M o m o in CO CM unp^
3bull t- fmdash o^ co tmdash vo co in co cmdash co in a
bull bull1 1-1 trade4 rH rH^ CO 4)2
~ plusmn4J o O CM ^_
o n CO vO J oraquo 0C0M
cu rH rH rH rH rHin tmdash
3 iCM 4J
^j CO CO
E O0 ltU -H n o c E
See
pag
se
rva
t
rH O in 0 0 O O 0
O o x rH Cmdash
0 0n
cu rH mdash O tmdash X o o o o c o o o o r H r H i n o i n i n o O
bull L in oo co oo oo o cy cr o rH CM o cr ONc fcJ bullH on en m m rn c^n rH rH rH0 pound CO 3 CO
t CM0gt s o o o in rA n ^o oo in tmdash oo 0gt zr =r a- JT JT$_
T)C CO
~ E CO ^ _bdquo ltu CO g r H r n c n i n o o r H r H
vgtO ^D O ^^ ^O CO ^^ ^^ JJ 2 4) rH rHCO t
c CO
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0
bullo co n ^
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CO
mdash^ bull cmdash CMin 1 gt rH vO vO O CTgt CO
s CTgt CO OO Ogt Craquo- tmdash cu O CO rH z 0
bull_bulllaquo
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4)bull
Z 3
^ ^ ^ ^ H r H r H r H r H rH r H C O r H C O a O C O a O a O C O C O r H i H r H CO OO - gt 0 0 ^ - gt ^ raquo - ^ ^ 1 - gt ~ gt - C O C O O O
U ^ raquo ^ - ~ raquo O ^ ^ O t ~ C O r H - r r ^ - ^ ^ JJ r H C M v O r H r H r H r H r H C M C M r H i n c r gt rH CO CM gt laquolaquo - - -^ bullmdash mdash bullraquoraquobullgt -v -v ^^
~ v O r H r H r H r H r H r H r H r H lt M C M C M CM O O r H r H r H r H r H r H r H r H r H r H r H r H rH
in rH cmdash
CO vo
CO vO
41 rH CO
CTgt rH raquo CM rH
cn CO
o 0 rn
CO cmdash
tmdash fshy
CM ao
iT rH
m
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CO t-
tmdash Cmdash
CM CO
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CTgt
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bull
CO bO C bullH T3
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28
excavation
West Landfill
Area
Legend bullmdash landfill limit -bullbull--bullexcavation limit r~~s stream
copy WNWNEECSESCSEN monitoring well locations
= == unimproved road
electrical resistivity sounding
feet Fig12 Electrical Resistivity Sounding Location
L
29
allow estimates of depth to water table and bedrocic to be made
Soundings were carried out to 500 foot electrode spacings to insure
that hredrock was penetrated and to facilitate interpretation These
results and a discussion of the soundings interpretation are
included in the analysis and discussion section Schlumoerger
resistivity soundings were made using a Soiltest R-bO unit
30
Model Development
The USGS Iterative Digital Model for Aauifer Evaluation was
usea to develop steady state flow models of the study area (43) A
flow chart of the computer model and a brief explanation of the
subroutines usea is presented in Appendix D The stream locations
elevations and aauiferlandfil1 geometry and hydraulic properties
were input to the model to compute head values at each 200 foot
grid spacing node (Fig 13) The input data which is for the
existing excavation and landfill conditon is listed in Appendix E
The head values that are computed at each grid space are in turn
loaded into the CalComp plotting routine (44) where a grid spacing
is setup with the computed head values at each node The contouring
program linearly interpolates between these head values and
generates a contour map The computer simulated ground-water
contour map for the excavation and landfill is presented in Fig
14
The streams in the model generally serve as controlling boundary
conditions When using computer simulated geohydrologic models of
an area choosing the boundary conditions for the model that are the
same as prevailing conditions in the field is a critical step in
model development Extending the models boundaries to areas in the
field that have a minimum influx of ground-water across them
simplifies the proolem of calculating fluxes from outside the model
area The eastern boundary is bordered by glacial till which has a
low hydraulic conductivity estimated to be 67 ftday(2) This
contrasts to the high hydraulic conductivity of glacial outwash that
makes up the model area of approximately 107 ftday(3036j
31 N
o 9
bullO O
32
33
The Saugatucket River serves as the controlling boundary on the
east A small drainage area directly to the east of it provides a
minimal influx
Beyond the moaels northern boundary the glacial outwash valley
extends to the base of a till covered h i l l on the western half ana
on the eastern side extends along the Saugatucket stream Due to
the relatively large drainage area that lies upgradient from the
northern boundary a recharge flux eduivalent to 10 inyr over the
drainage area on the till hill and outwash area north of the model
area was input as underflow (Fig Ib) Part of this was input at
each northern boundary node Till has a lower infiltration capacity
than outwash so more of the precipitation w i l l be transmitted as
overland runoff resulting in a lower ground-water baseflow The 10
inyr of recharge that results in a ground-water inflow from the
combined till and outwash region represents an estimate that is
smaller than the 14 inyr recharge for glacial outwash areas in
Rhode Island (25)
The glacial outwash valley extends beyond the western boundary
No significant ground-water recharge flux was estimated at this
boundary A relatively low ground-water gradient exists to the west
of this which does not provide a significant flux across this
boundary Tne southern boundary is basically the outflow region for
the area and therefore would not reauire any ground-water flux into
the moael area across this boundary This boundary was set south of
the point that the streams in the model merge together Therefore
the streams which lie to the north of it are the controlling
34
scale 124000
Fig 15 Northern Drainage Area
35
boundary conditions The flux out of the downgradient outflow
region approximately eauals the influx from precipitation recharge
and boundary influxes
When tne stream configuration in the moael area are reviewed it
can be seen that they comprise a large portion of the boundary
area The screams can act as sources or sinks for water in the
model thus providing to and removing water from the aquifer The
leakance option was used in the model which provides for a confining
bed and aouifer area beneath the stream to be input
The leakance is defined as the hydraulic conductance of the
streambed divided by the streambed thickness which in this case is
taken as 1 foot The leakance value at each streambed node
restricts the flow between the aduifer and the stream The
streambed hydraulic conductivity is typically 01 the value of tne
hydraulic conductivity of the aduifer (717) The value 107
ftday was used for a streambed conductivity based on a value of
107 ftday for the aquifer The aduifer and stream hydraulic
inputoutput exchange at eacn node is calculated by initially
finding the difference between the initial field stream head
elevations and the computed head elevation values at the
corresponding nodes This head value is then multiplied by the
(Leakance value at each node) x (stream area of each node)
Therefore if the aduifer head was lower than the stream head the
stream would act as a source of water for the aquifer and vice
versa
36
Tne leaxance input at each stream node is the ratio of the
actual field streambed area in each node to the area of each node
which is 200 ft x 200 ft = 4 x 104 ft2 The west
excavations stream width is approximately 3 ft central 4 ft and
east 5 ft Therefore if tne west stream traverses the node
directly without meandering it presents a leakance of 3 ft x 200
ft4 x 104 ft = 015 Leakance and streamhead values were
input at each node to set up the stream flow parameters in the
models
A recharge value of 14 inyr over the entire area was input at
each node This represents a value of precipitation that is
transmuted into tne ground-water rather than being directly
evaporated evapotranspired through plants or overland flow
runoff The precipitation recharge flow from the stream into the
aauifer and boundary fluxes provide the model witn input flow
parameters
From analyzing the available information it was determined that
the study area lies within a glacial outwash area with a relatively
shallow bedrock The seismic survey around the landfill generally
indicates a depth to bedrock below the land surface of approximately
29-43 ft with corresponding saturated thicknesses of 19-33 ft as
seen in Table 2 This agrees with borings from tne USGS groundwater
map in the stuuy area (18j The seismic survey was run at a low
water table condition which was several feet below the high water
table level (Fig 9)
37
High water-table saturated thicknesses were used to develop
model parameters For the purpose of this model study the saturated
thickness was set at 30 ft except in the vicinity of well W where
there is a bedrock high (Fig 8) At this location a high water
table saturateo tnicxness of 8 ft was estimated In tne vicinity
the seismic survey was conducted the bedrock elevation at this
location is the highest and the saturated thickness the least Tnis
can be seen by an east-west cross section of tne landfill (Fig 16
The boring log for well W indicates a sand trace gravel outwash
material (Appendix B) Boring logs at the eastern landfill area N
and E indicate similar material On this basis the hydraulic
conductivity was estimated at 107 ftday (3036) Witn the
exception of the landfill and the bedrock hign areas the
transmissivity values were set at 107 ftday x 30 ft = 3210
fto day From the literature the hydraulic conductivity of the
landfill material was estimated at I ftday (19) The
transmissivity of the landfill material in tne nortnern section was
estimatea at 1 ftday x 30 ft = 30 ft^day or approximately two
orders of magnitude lower than the outwash In tne landfills
southern section the original excavation was not as deep as in the
northern parts The landfill material was estimated to makeup only
one half tne saturated depth the remainder being the original
glacial outwash material (Fig 17) Therefore the transmissivity
at the southern end was estimated at 15 ft x 107 ftday + lb ft x
1 ftday = 1620 ft^day These values were graded into the 30
ft^day values at the landfills northern halfway point These
38
were input as transmissivity values to the model at their respective
locations This model did not use the water taole option so
water-table fluctuations did not affect the transmissivities
39
O
-8 Oi0
co o
CO
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3
O or
bullo c 10
ogt o laquorf o
c o o e 0i
CO to o k O
co CO LU I
09 O
bullo c 01
CO
C9
UO|JBA9|a
40
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a o co
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coI co co O w O
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bullo c 09
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Model Calibration
A simulation was run using the initial estimates of stream
parameters aquifer and landfill hydraulic conductivities
transmissivities boundary and recharge conditions to approximate
water taole conditions in tne fiela Initially the existing
condition of the excavation area to tne west of Rose Hill Road and
the landfill to tne east were modeled in order to calibrate the
model to current field conditions as shown on Fig 4 The simulated
well values (Fig 14) fall within tne range of field values (Fig
9) The resulting contours also provide an approximate matcn This
can be seen by comparing Fig 4 with Fig 14 An additional check
was to match the flow loss and gain in the streams between tne weirs
in the central stream which w i l l be discussed later The
simulated flow value from the excavation drainage stream is the same
as that measured at the SW weir location Having calibrated the
model by approximately matching well water levels nead contours
and scream flow values different field conditions and possible
remedial measures can be simulated
When the model grid was laid out over the study area as viewed on
Fig 13 the stream configuration rarely traversed the grid nodes near
their central axis When the stream locations were input to the
computer the information was documented as crossing the central axis
of the grid nodes The result of this is a slight aberration when
the actual stream configuration is laid over the computer graphics
head contour output The streams dont always cross the groundshy
water contour at the logical location Rather than modifying the
actual stream configuration to adjust then to the computer output
their actual locations are presented
42
Simulations
i The primary focus of the computer modeling is to analyze flow
patterns under changing conaitions in the near vicinity of tne raquo
landfill The study areas overall flow patterns as they exist
today are first presented in order to realize the lateral east-west
head contour lines between the stream that directly borders the
landfill on the east side and the SaugatucKet stream (Fig 14)
This indicates a general southerly flow direction in that area As
different conditions are modeled these contours generally maintain
their east-west orientation In order to facilitate interpretation
of flow patterns in the near vicinity of the landfill flow patterns
to the west of the stream that borders the east side of the landfill
r are presented in the subseauent models
L- Natural Conditions
The results of modeling the original natural conditions are
shown in Fig 18 The excavation and stream to tne west of Rose
Hill Road and tne landfill did not exist in this simulation The
southwestern boundary consists of a drainage stream that was
delineated using an aerial photograph and stream elevations were set
using the topographical map The USGS ground-water map (18) was
used to estimate head values between the west excavation and north
streams These were input to the model as constant heads on the
models western boundary The resulting simulation generally matches
the southeasterly flow direction that is indicated on the
ground-water map (Fig 5)
A3
Legend
x-^- stream 400 = = = unimproved road
I f ee t
Fig 18 Natural Conditions
44
Excavation Without Landfill
The condition of the excavation to the west of Rose Hill Road
with its resultant drainage stream without the landfill was modeled
next (Fig 19) The extent of the excavation ana the location of
the new drainage stream were delineated using the aerial
photograph The west stream elevations were sited in the field and
used in the model The concept of a confining streamoed layer was
excluded in tne excavation drainage stream under the concept tnat no
significant organic layer had been built up within the 25 year
period that the excavation had been initiated Head values between
the west and north stream boundaries were interpolated and input as
constant head values on the northwestern boundary The west
excavation drainage stream creates a condition that alters the
natural ground-water flow patterns by creating a more southerly flow
condition the drainage stream providing a more immediate surface
outflow in that area
Landfill Without Excavation
The hypothetical case of a landfill without the excavation was
modeled next (Fig 20) The low hydraulic conductivity zone of the
landfill changes the natural flow conditions and creates noticeable
mounding This is evidenced by the decreased spacing of the head
contour lines and deviation from the lateral contour lines of the
natural conditions and higher head values (Fig 21)
45
Legend
excava t i on s t ream
400 unimproved road
f e e t
Fig19 Excavat ion without Landfill
46
Legend
landfill limit
bull - s t ream 400 copy WNWNEECSESC
monitoring well locations f ee t bullbull-bull=bull unimproved road
Fig 20 Landfill without Excavation
1
oin CM
bull
m u
0)rf
oO
bullo 9
bullo 9
o rf o o CO 1
lt0inO O
T ^ogt
c o
47
o9 aI 0)
ot_3 O laquolaquo coO bull3 OJ oX
bulla caj
CM
UO|IBAraquo|
48
Landfill ana Excavation
The condition of tne existing landfill and the excavation with
the dam is the next condition modeled (Fig 22) The ground-water
elevations used to calibrate tne model correspond to an actual high
water table condition Between the NVJ and pound weir a streamflow loss
of approximately 102 gpm occurs aoout 60 percent of this flow is
lost at the dam site which maintains a head of b-6 feet over an area
of approximately 1800 feet^ This approximates a field value of
1144 gpm influent to the aduifer between the NW and E weir on ]2
December 1981 (Table 3) From the E weir to the SE weir a net
increase in flow occurred of 74 gpm which corresponds to field
increase of b62 gpm
The surface runoff from tne landfill flows primarily toward tne
eastern side of the landfill Increases in water-table elevations
on the eastern side after heavy rains such as the 11 November 1981
storm indicates that this runoff increases outflow gradients to the
stream and therefore increases streamflow Surface runoff input is
not modeled which explains in part why field stream inflow values
are slightly higher than model predictions especially for periods
after a storm has occurred The flow from the SW weir located at
the southern end of the excavation represents drainage outflows from
that area The net flow calculated in the model was 140 gpm
which approximates field conditions of 1642 gpm on
December 9 1981
49
d f l f reg N E
shy
Legend
landfill limit -bullgt-bullgt- excavation ^-N_X- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road
-40mdash approximate groundwater contour
400
feet
Fig 22 Landfill and Excavation with Dam
50
The modeled flow patterns suggest how the various contamination
zones around the landfill have developed to their present state
They indicate a flow to both the southeast and southwest on their
respective sides of the groundwater divide Evidence of a
southwesterly contaminant flow is presented when the continued high
specific conductance contaminant level in tne observation seepage
hole is realized (Table 5 ) In addition the specific conductance
increase in the west excavation stream is evidence of an influent
contamination flow
Contamination flow to the eastern and southeastern side of the
landfill is obvious High specific conductance levels in the wells
on the eastern side (Table 4 ) a specific conductance increase
between the E and SE weirs (Table 5 ) and contamination in the NE
domestic supply well (Fig 3) present conclusive evidence of
contamination to the eastern side of the landfill
An anamalous condition that exists is a domestic supply well
located approximately 300 feet due south of the landfill remains
uncontaminated (Fig 3) Flow patterns indicate that contamination
would be transported from the landfill south to this area
(Fig 14) One explanation is that a pocket of clay at the southern
end of the landfill area was discovered in the original excavation
for the landfill (lt6) This evidently prevents leachate from
reaching this wells radius of influence
51
Summer Conaitlon
As described earlier during dry months of the year the stream
that normally borders the northern and eastern side of the lanafill
may dry up as far as a point southeast of the E well Tnis
condition existed from the 15 August 1981 to the 27 October 1981
period when streamflow commenced in the northern part of the stream
yet did not overflow the north dam until 17 November 1981 This
created the present day continuous flow condition throughout the
stream These summer conditions were modeled by removing the stream
above the aforementioned location while other conditions remained
the same (Fig 23) Summer condition well water levels listed in the
model generally match field low water table conditions (Fig 9)
Because there is no stream upgradient from the landfill to provide a
stream head and infiltration through the streambed groundwater
runoff from the area north of the lanafill is the controlling flow
input In these moaels an average recharge of 14 inyr was used
which represents a yearly average The summer recnarge conditions
are prooably lower given the effects of decreased rainfall and
increased evapotranspiration during the summer months A domestic
supply well whicn exists northeast of the landfill (Fig 3) nas a
greater potential to be contaminated from the lanafill at tnis time
than when the stream is flowing Flow patterns from the landfill
are such that during an upper stream no-flow condition groundwater
flow patterns are more in an easterly direction than in a
southeasterly direction The stream would act as a source of
infiltrated water upgradient from tne landfill and provide a
52
I ^N gt i I i j i -r- -bull- bullr -T- t- -r- i- TJ JV
bullbullT laquo ^ O - laquo bdquo xi cshy
H r^~ I -~- --^ X- = mdash x^ N
^--^ A bull O^NW -v - gt-bull Ni i I _____mdash - bull laquo l - mdashmdash 1 deg I ^ltv I C
I reg NE A
Js bull vbull A ~ - v T gt- ^ ix - N
-5Z- | N TfS lV I -bull bull iA i gt gt I ^ bullr-Ky L bull 1 _- copy]wgt-- - bull- mdash - - shy
= r Y ~mdash ltmdashA A
^^-lt A _ - - - - bull Hmdash - reg EC x ^-mdash mdash I ---mdash_mdash -t-V-^N - y
I- -bull - r x i X
V ^ 7 I -v (^~~^^r ^^^
sc Emdash-bull vV JI - - - ~ r )N y- -
X - bull r bulllt
^bull^ y y Jlaquo^ - -lt shy
T s^ lt^ ^ +^-b (
X
Legend
landfill limit j-j-bullraquobull excavat ion gt^ -x- s t ream
reg WNWNEECSESC monitoring well locat ions
= == unimproved road fee t
Fig 23 Summer Condition
400
53
constant head across tne northern section of the landfill This
would tend to orient the flow in a more southerly aowngradient
direction In addition the stream which flows adjacent to the
northeastern well could provide a source of infiltrated clean water
to it which would minimize the possible contamination from landfill
leachate
Without Dam
During tne spring scream flow condition the dam failure which
occurred between the 15 March 1982 ana 9 April 1982 monitoring
periods decreased flow to the aauifer and landfill This eliminated
the 5-6 foot head difference over a 19000 ft^ area which had
created a larger area and elevation head for infiltration to occur
The condition without the dam was modeled by reducing the area
encompassed by the dam to a 4 foot wide stream channel thus
reducing the leakance value at that node (Fig 24) The flow change
from the stream to the aduifer between the NW weir and E weir
reduced the model flow loss to 50 gpm Tnis corresponds to the 9
April 1982 monitoring period which indicates a 30 gpm loss
As compared to the previous flow loss in the upper stream
sections to the aauifer the 21 April 1982 and 22 May 1982
measurements between the NW and E weirs indicate a flow gain The
streamflow conditions have changed from an influent
stream-to-aauifer condition to an effluent aduifer-to-stream
condition that increases flow downstream
54
Legend
landfill limit j--i--i- excava t ion x-gtmdash^- stream 400
copy WNWNEECSESC monitoring well locations
= == unimproved road f e e t
Fig 24 Landfill and Excavation without Dam
55
Analysis and Discussion
In order to fully understand flow patterns and Quantify leachate
outflows at the landfill it is necessary to arrive at an estimate
of flow inputs from precipitation ana upgradient sources In the
following analysis it will be demonstrated that the rainfall input
to the landfill is the factor which controls leachate generation A
calculation using the H inyr recharge over the area of the
landfill was made to estimate the leachate outflow due to rainfall
infiltration An estimated 134 gpm is generated from the entire
landfill area Simulation of the existing conditions (Fig 24)
indicates a groundwater divide in the landfill is located
approximately at the western third Therefore approximately 23 of
the generated leachate flows to the eastern side of the landfill or
9 gpm The effect of the flow input from the upgradient stream is
evident when tne summer condition witnout the stream is viewed
(Fig 23) Without the stream to infiltrate the landfill and the
recharge and northern boundary condition as the flow inputs the
head at the northern end of the landfill drops about 5 feet from its
previous value A flow pattern from the north central part of the
landfill to the eastern side indicates a 12 feet head difference
with recharge - but with the upgradient stream a 16 foot head
difference occurs Considering the transmissivity change the
stream would increase the leacnate outflow from the landfill
approximately 43 under a low water table stream influent condition
to the aauifer This would increase leachate outflow to the east
side to approximately 129 gpm This value approximates the
56
outflow at the SE weir location during the summer monitoring period
when the upper stream was not flowing (Table 3) The outflow from
the western third of the landfill whicn lies to the west of the
ground-water divide would be approximately 63 gpm
Realizing the importance of infiltration to tne landfill as a
major influence on the generation of leachate an analysis of this
w i ll be discussed An estimate of infiltration was made using the
precipitation recora for October ana November (Appendix A) During
this time period a minimum of direct evaporation ana
evapotranspiration occured and the grouna is not yet frozen The
top cover over the lanafill is generally 05 ft to 2 ft of local
sandy soil and subsoil availability determined what was used The
top of the landfill is at an elevation of 92 ft as compared to the
ground surface at well W which is at an elevation of 76 ft
(Fig 25) This compares to the well W water level which is at an
elevation of approximately 52 ft This creates a long path for
infiltration through the unsaturated zone The topcover generally
slopes eastwara at a grade of 2-5 The west side maintains a
relatively steep slope of 10-15 ft drop within 50 ft ana the north
and eastern slopes have a more gentle slope of approximately 10 ft
within 100 ft distance An unlined surface arainage swale channels
surface runoff from the northern section of the landfill past the
NE well to the eastern side ana low area in the vicinity of the E
well This has a drainage swale to an area near the stream but
doesnt directly connect to tne stream A poorly graaed drainage
swale exists on the landfills left side The landfill material has
57
excavation
seepage observation ^
hole
Legend bullmdash landfill limit -^--excavation limit r^s- stream
copy WNWNEECSeSCSEN monitoring well locations
--- unimproved road O location of amp Inf i l t rometers O
feet
Fig 25 Infi ltrometer Locat ion and Drainage Feature
58
been placed in 10-12 ft cells and covered with 1 ft of soil at the
end of each day The material has settled differentially creating
areas for depression storage
An estimate of the percentage of precipitation that infiltrates
the landfill was made from precipitation records recorded well
elevations and an estimated specific yield for the landfill
material The volume of water that infiltrated should eaual tne
specific yield multiplied by the well water level rise Several
recharge periods were studied using this relationship Once the
percentage of precipitation that has infiltrated is determined the
percentage that is translated into runoff is simply the remaining
percentage if evaporation is neglected
From the literature for a slightly inclined slope of 2-5
typical runoff coefficients range from 10-20 in either sandy or
heavy soil (16) The landfill cover is generally sloping to the
east which creates a long path (approximately 400 ft) before the
runoff reaches the steeper slope on the eastern side of the landfill
of 15-20 The long drainage distance creates a greater time for
rainfall to infiltrate Another consideration is the actual
capacity of the soil to conauct water into the soil which was tested
in the field using double ring infiltrometers An average initial
percolation of 8 mmhr the first hour and a subseauent rate of b
mmhr occurred (Fig 26) The 8 mmhr rate compares well with
other sandy soil infiltration rates (14) Therefore if the
intensity of the rainfall exceeded a 5 mmhr rate for several hours
59
CO + 09 o
E o
CO
o Z pound C
O
C9
o DC
CO
CD CM
ogt CO N- to -4 CO CM
jq tuu i U O | raquo B J J | | J U |
60
on a poorly drained surface the additional rainfall would be
translated into runoff because the soils infiltration capacity had
been exceeded
The initial 8 mmhr infiltration rate was due to the pore spaces
in the sandy soil being filled and the subsequent 5 mmhr rate was
percolation into the low permeability landfill material The tests
were conducted in November assuming a minimal evapotranspiration
and the field capacity of the sandy soil had been maintainea
The W well was used as representative of the water elevation
changes in the landfill because it is directly adjacent to the
landfill 900 ft distant from the upgradient stream This minimizes
the effect of infiltration from the stream and maintains a high
contaminant level During periods of high runoff conditions excess
surface water ponded in a poorly graded drainage swale on the west
side and directly adjacent to the landfill This influenced the W
well at a time the contamination level dropped (Fig 11) Before
this occurence in mid-December the rise of the W well closely
matches that of the SC well and a background well SK6 which is
located outside the study area (Fig 7) Therefore it was analyzed
as a valia indication of the water level rise during the mid-October
to mid-December period The monitoring of the SC well was
intermittent due to inaccessaoility because of 10 ft extensions
being placed on the well as the refuse was being filled in arouna it
61
A high rainfall period from 14 November 1981 to 1 December 1981
was chosen for the initial study period The effects of
evapotranspiration were neglected due to the cool temperatures
experienced at this time Therefore it was assumed that the field
capacity haa been reachea and tnat any additional input to tne
unsaturated zone would result in direct percolation to tne saturated
zone During the time period 14 November 1981 to 22 November 1981
029 ft of rainfall fell and the well W rose from 488 ft to 493
ft - a 05 ft increase During the next 8 day period there was no
precipitation yet the W well continued to rise to 4972 - a 042 ft
increase The slow percolation of water through the landfill
material would account for the latent rise in the well water level
From previous reports a specific yield for refuse was estimated to
be 028 (1920) This value is dependent on the original compaction
of tne material age and resulting consolidation
During the 14 November 1981 to 1 December 1981 period 029 ft
of rain fell and the well increased 092 ft The following
relationship is used to evaluate the infiltration value and runoff
I = (Sy) h
Sy = specific yield
h = well rise
I = volume infiltrated
I = (028) (092 ft) = 0261 ft
62
The difference between the precipitation and the infiltration is
the runoff (assuming no evapotranspiration) Therefore 029 - 026 =
003 and furthermore 003029 - 13 runoff This corresponds in
the literature to a typical runoff coefficient for an inclined
surface of 2-5
Analyzing a longer precipitation period from 18 October 1981 to
1 December 1981 a net precipitation of 043 ft (accounts for
evaporation) occurred less 10 for runoff or 039 ft infiltrated
This results in a 139 ft elevation increase The well water level
actually increased 132 ft shy only a 5 deviation from the
calculated
From tnis investigation it is seen that a large proportion of
the precipitation has the potential to be transmitted into the
landfills saturated zone Exceptions are wnen heavy precipitation
periods exceed the soil percolation capacity frozen ground prevents
infiltration and direct evaporation and evapotranspiration recycles
the ponded surface water and infiltrated soil moisture back to the
atmosphere In retrospect water temperatures within the monitoring
wells could have been measured to indicate thermal effects from the
landfill on ground-water temperature Ground-water temperatures
were assumed to be 50deg F (9)
63
Specific conductance measurements serve as an indication of
contamination levels These measurements are used to trace leachate
movement which represents ground-water flow patterns Factors which
must be considered when monitoring pollutants are the attenuation of
the leachate contaminants which occurs both in the zone of aeration
and the saturated zone The former is a more complete process
Dilution dispersion and cation exchange are the primary factors
involved in decreasing leachate concentration in the saturated
zone The glacial outwash materials of southern Rhode Island do not
have a cation exchange capacity or a high buffering capacity so
attenuation is simply by dilution and dispersion (22)
The NW well consistently exhibits relatively low specific
conductance levels even though it is in landfill material It is
situated in a drainage swale and ground water elevations range from
543 to 5944 This is several feet below the upgradient stream
elevation of 64 feet which is less than 400 feet away The bottom
of the wellpoint is at an elevation of 5312 feet well into the
landfill material Infiltration from the stream to the landfill has
occurred at this location
The W well is situated on a bedrock high adjacent to the
landfill approximately 900 feet from the upgradient stream and its
water level is higher in elevation than the excavated pit (West
Observation Hole) which is 300 feet directly west The W well
maintains a contaminated level A poorly graded drainage swale to
the west of the landfill provides areas for extensive ponding and
infiltration to occur which explains the drop in conductance after
a high runoff period
64
The SC well is located in landfill material and has a
conductance of over 8000 umhos This indicates that leachate is
undiluted The oottom of the wellpoint is at an elevation of 389
feet which is situated in the landfill material
High specific conductance measurements in the west observation
hole and well W and their relative elevations indicate a
west-southwesterly flow direction from the landfill Infiltration
recharge and leakance from the stream into the landfill provides the
necessary elevation to cause outflow in this direction
Contamination from the landfill to the surrounding streams is
evident (Table 4) During the period 15 August 1981 to 27 Octooer
1981 there was no flow in the stream that Borders the northern and
eastern side of the landfill until a point just south of the E well
was reached High specific conductance levels in the EC and NE
wells were recorded (1000 jjmnos) At a point directly east of well
EC a pool of water existed that was relatively uncontaminated which
is designated as the East Stream] location (Fig 10) At a point
just south of that (East Stream^ polluted water in the streambed
was flowing at a low rate This was measured at the SE weir
location and which had a high conductance also Flowrates varied
between 6 and 23 gpm and specific conductances were over 350
pmhos This low water table condition flowrate is the baseflow from
the eastern side of the landfill and indicates a southeasterly flow
direction from it
Streamflow commenced in tne northern part of the stream 21
October 1931 and the north dam oegan to f i l l Stream specific
65
conductances were low indicating a clean water source Tnis
continued until 17 November 1981 when the dam overflowed ana flow
throughout the east stream began A weir was placed at the Rose
Hill Road NW location and was compared to flowrates at the SE
location Flowrates decreased and specific conductances increased
between these two locations
To further investigate the condition of a lower flowrate
downstream than upstream an intermediate weir was placed at the E
weir location (Fig 9) This snowed tnat the stream from the M
weir to the E weir was losing water to the aauifer (influent
condition) and gaining water at the SE weir (effluent condition)
The condition of a net loss of water between the NW and SE weirs
remained until 19 December 1981 when a snowmelt rain condition
caused increased surface runoff and a net increase in flow at the SE
location Upon analyzing the March and April 1982 streamflow
conditions the expected case of a net ground-water pickup from the
E to SE weir continued The explanation for tne initial net loss of
ground-water is the fact that the leakance from the upstream section
was being discharged into aauifer storage to raise the ground-water
table to an eduilibrium level Upon reaching a high recharge
equilibrium steady state condition any additional input will
eventually be transmitted as baseflow out of the landfill and a
downstream net pickup will occur A hign water table condition
prevailed during the January through May period maintaining this
condition In April the north dam broke through reducing the head
in that area by 4-6 feet The 9 April 1982 monitoring revealed that
66
an influent condition remained between the NW and E weirs but at a
reduced rate The 21 April lower stream flow condition shows a
small pickup of water between the NW and E weirs indicating the nigh
water table and low stream flow conaitions combined with the absence
of the dam had changed the conditions to an effluent condition
This was evident in the May monitoring period
Evidence of contamination on both the western and eastern sides
of the landfill supports the existence of a ground-water divide in
the landfill The west stream which drains the excavated area to
the west of Rose Hill Road shows contamination pickup between its
northern section and the SW weir The W well and ooservation hole
indicate high contamination levels which reinforces the concept of a
contaminant outflow to tne west excavation stream
As shown previously flow towara the eastern side of the
landfill is evident from the nign specific conductances and specific
conductances increases in the stream This is especially evident
during low flow conditions when the stream starts at a point to the
east of the landfill and flows with high specific conductance levels
From the literature a relationship between specific conductance
and dissolved solids exists the dissolved solids (mg1) are
approximately equal to the specific conductance times a factor
ranging between 55 and 09 (39) in this case it is taken as
065 (41) The dissolved solids increase coupled with the stream
flow increases provides a basis of calculating the dissolved solids
outflow to tne stream This calculation method was used in a
previous study (26)
67
The relationship
=Cinout Coutflow Qoutflow - Cupstream Qupstream Qinput
where the numerator is the streamflow pickup and the C- and
Q-jnput is the concentration and flow input from the ground-water
This can be used to estimate dilution level outflows from the
landfill Initially this is used for the ambient ground-water
pickup between the E weir and the SE weir This entire flow doesnt
come from tne lanafill but much of it is conaucted in the high
transmissivity area between the lanafill and stream from upstream
leaxage ana surficial recharge Tnis is evident when this section
of the flow pattern is analyzed on Fig 22 Therefore the landfill
outflow is mixed with tne ambient groundwater flow which dilutes the
landfill leachate before it enters the stream To illustrate-this
concept a calculation using the 9 December 1981 monitoring is used
At this time a flow of 672 gpm occurred at the SE weir with a
specific conductance increase of 7 ymhos between the E and SE
weirs The dissolved solids increase would be approximately 795
Today in tne stream
Where
Co = 90 jumho at SE weir
Qo = 672 gpm at SE weir
Cus = 83 jumho at E weir
Qus = 606 gpm at E weir
Qinput = 66 gpm gain
Cinput = 154 jumho
68
The 154 jumho value represents the contaminant level in the
ground-water adjacent to the landfill
This relationship is applied to approximate the concentration
level dilution in the ambient ground-water between the landfill and
stream The aforementioned relationsnip is in turn applied to the
landfill outflow into the ambient ground-water flow adjacent to the
landfill The ground-water receives landfill leachate dilutes it
and then transmits it to the stream The previously calculated
value of 129 gpm was used as the outflow from the landfill
Co 154 jumho flows into stream
Qo = 67 gpm flow into stream
Cus = 83 jumho background level
Qus = 67 gpm - 129 gpm = 541 gpm
Qinput = 129 gpm from landfill
Cinput = 451 jumhos
Approximately tne same contaminant levels from the landfill (tbl
umho) are arrived at as existed in the summer streamflow conditions
when the upgradient ground-water flow adjacent to the landfill was
at a minimum
In addition to using specific conductance to define
contamination zones electrical resistivity can be used to indicate
contaminated areas The measured earth resistivity is inversely
proportional to the conductivity of ground-water Water containing
contaminants with high ionic concentrations are more electrically
conductive and will have lower resistivity values than surrounding
natural ground water Therefore resistivity methods can be used to
69
delineate plumes of contaminated ground-water that have hign
specific conductances This has been demonstrated by several
investigations (11122328374045)
In this study a Schlumberger vertical electrical sounding R-l
was made in an area of known contamination at the W well (Fig 12)
Given the geologic constraints provided by the well boring log a 4
layer computer model was used to match field survey values A
Schlumberger sounding R-2 in an uncontaminated area north of the
landfill in the same geologic setting was used to provide a
comparison background sounding (Fig 12) A seismic survey N-4 was
made to obtain water table depth and depth to bedrock as input
parameters to a four layer resistivity model (Fig 8) Tne results
of the electrical soundings have been tabulated in Table 6 and
plotted in Fig 27 and 28 respectively
The ascending portion of the field Schlumberger curves were
initially matched using a two-layer ascending type master curve to
provide an approximate depth and apparent resistivity of the
overburdened topsoil layer (8) Tne second unsaturated layers
apparent resistivity was determined by using the graphical
interpretation of total transverse resistance The total transverse
resistance is approximately eoual to the peak value of the curve
times the corresponding Ab2 distance it occurred at This in turn
is eaual to the sum of the first two layers apparent resistivity
times their corresponding layer depths
70
bullH
OJ bull bullH 4J CO CM
c ce G bullrH
j-gt ca c c a 3 ltu O L
co CO 0
bullo Q bull laquos c n 3 -U OrH f~ 3 bO ltn y CO O cc CO ^mdashN
QQ bull
bO bOJJ C C Ci_i
O l T i O O O O O O O O O O O O O O O O bullH bullH mdash^ bullo 0 C c3 f| 3 O raquo O CO CQ
CO
rH
CO O
L 4J
^ltU
i- 1 ^n ^b O 4-) bull2 CM bullH C OJ 1 -U bullH CO C L O a ^-^ 0) a
rH c a L CD ltu (1) 3 tlt bO cO I
3 a 0) a Q 4J laquoa e CO 3 (H bO c C O bullH
CO TJ C 3 bull
bull O bO -i-3
0 CO C O3- O G O O O O O O O O O O O O O O O O O O ft rt1 -raquo - t l S^ ft tfigt f I mdash^ K_ l_ raquo mdash I gt fgt I l 1
(1) 0 rH CO CJ JD o^^ CO CO CQH lts
71
Legend
A actual field measurement
-e- interpretat ion
10000 bull
6000 bull 5000
4000-
3000shy
pound2000| ltD
_ r 1000
09
5 600 pound 500 - 400
I 300 a a lt 200
100 10
Fig 27
20 30 4050 100
Distance AB2
Schlumberger Sounding
200
feet
R-1
400 600
72
loooot
6000 5000 4000
3000+
laquo2000 e
r 1000
raquo 600 pound 600 ~ 400
$ 300 a a lt 200
100
Legend
A actual field measurement
-Qmdashinterpretation
10 20 30 40 50 100 200 400 600 Distance AB2 feet
Fig 28 Schlumberger Sounding R-2
73
Formula T = f
Background Sounding (9000)(15) = (3110j (1 7) + gt2(8)
= 16214 n- ft
W Wel l Sounding (b200)(60) = (500) (2) + pound2(28)
= 13250 SL- ft
To determine a resistivityp3 value for the third layer a
graphical interpretation for the longitudinal conductance S was
used(48) This is eaual to the sum of each individual layers depth
divided by their apparent resistivity
Formula S = -r1 +~r-raquobull-ra
Background Sounding 0017 = yyg + ~^
= IbOU - ft
W Well Sounding 0285 raquo -ggg 7^3 J~
= 179 v-ft
These values were input to a program which calculates a
schlumberger sounding curve (47) The theoretical sounding curves
approximately match the field curve as viewed on fig 27 and fig
28 To provide a check on the apparent resistivity of the saturated
layer at the W well the following relationship was applied 1OOOO
= spec-jfic conductance (umhos)
74
At the W well the specific conductance was measured to be 3 00
jmhos at approximately 10degC
Assuming a formation factor of 45 for the glacial outwash (23)
material Archies law is applied to estimate an apparent resistivity
of the third layer (7)
fgt FF x p
A= 45 x 103-n-ft
A= 4G3 JL-ft
This is a reasonable approximation to tne 3i= 179^-ft calculated
analytically from the sounding curve interpretation
75
Remedial Measures
With the analysis of f low patterns and contamination zones
recommendations to minimize the environmental impact of the leachate
can be reviewed The basic technique is to minimize all sources of
water reaching the refuse so that leacnate production is minimized
The oiversion of precipitation by a relatively impermeable cover and
proper channeling of runoff would minimize percolation into landfill
material Caps and seals can be constructed of clays fly ash
soils soil-cement lime stabilized soil memorane liners
bituminous concrete and asphalttar materials (15) Proper
contouring and grading will help minimize infiltration If a soil
cover is used a vegetative cover can be planted which will utilize
some of the infiltrating flow through evapotranspiration losses
during the growing season By minimizing the length of slopes and
providing proper drainage channels tne surface runoff can be
conveyed to a downgradient area outside the recharge zone
Therefore this surface water will not increase leachate production
from the landfill Also by increasing the slope of the cover over
the landfill itself a higher percentage of runoff and lower
infiltration will occur
To minimize upgradient ground-water influx to the landfill an
impermeable subsurface barrier or intercepting trench could be
used Barriers can be made of bentonite slurry-trench cutoff walls
grout curtains or sheet piling cutoff wal ls extending to the bedrocic
or an impervious layer to effectively prevent water passage or
create a head loss that wil l lower the water table In addition an
76
intercepting trench which has a perforated drain at tne lowest part
of the water seepage zone could be used to intercept and divert the
entire flow
These possibilities have been evaluated with the help of the
model to determine workable solutions for this landfill The
primary concern is to eliminate leachate flows to domestic wells
Initially a simulation was run that eliminated recharge over tne
landfill area (Fig 29) This had a considerable effect on the
ground-water flow patterns of the landfill area The mounding that
had previously occurred under normal recharge conditions was
eliminated and a general drop in the water taole within the landfill
of 2-3 ft occurred The effect of eliminating recnarge over the
landfill when the upper stream is running would cause greater
infiltration from the stream as evidenced by only a 2 ft head loss
in the landfills flow conditions This is evident when comparing
Fig 29 with Fig 24 Tnis indicates that this measure would only
marginally reduce the resultant leachate flow from the landfill
material that lies below the water table In another situation
where there is not such a strong potential for upgradient flow this
measure has proven quite effective (6) In this case the landfill
cover consisted of four layers an intermediate sand and gravel
cover immediately above tne regraded waste materials a 4 inch sana
bed designed to protect the overlying membrane a ilO mil flexible
PVC membrane and an 18 inch final cover of sand and gravel
77
Legend
landfill limit -raquo- -^ -raquobull excava t ion x-^x- s t ream
400 copy WNWNEECSESC monitoring well locations
= -= unimproved road fee t
Fig 29 No Recharge over Landfill
78
Controls such as 10-30 mil polyvinyl chloride covers favor the
development of an anaerobic environment which increases waste
decomposition time and would necessitate installation of gas vents
at several locations on the landfill cover Tne integrity of tne
synthetic cap may be further threatened by subsidence which create
differential stresses on liners Settlement would create areas for
ponding and depression storage and eventually necessitate regrading
the landfill surface The landfills south-central area has oeen
filled within the last year and will prooably need to be regraded
due to settlement within the next few years
Another possibility for a liner would be a soil-bentonite
cover A layered cover consisting of natural materials with low
permeabilities such as bentonite clay followed by a layer of highly
permeable material such as sand and finally a layer of topsoil can
be used Due to potential drying out and cracking of the clay liner
a synthetic liner is the preferred method
The most immediate technique is to grade contour and vegetate
the landfill cover which has been done at this site Althougn an
impermeable cover would probaoly reduce the amount of leachate
produced it would not eliminate the upgradient flow and provide
guaranteed protection of wells in the vicinity of the landfills
northwestern section
A slurry trench along the northwestern perimeter of the landfill
would effectively cutoff upgradient infiltration and divert recharge
infiltration in a southeasterly direction thus removing possible
leachate outflows from the radius of influence of the neighooring
79
wells This has been simulated using the computer moael ana flow
patterns as shown in Fig 30 Contour lines are distorted in the
vicinity of the slurry trench due to the 200 ft nodal spacing
Transmissivity values of 1 ftday were input at the slurry
locations to simulate an impermeable barrier Tne surface recharge
at those nodes does not infiltrate the relatively impermeable grid
nodes at the slurry locations and flows to the edge of the noae
thus creating a dramatic head loss within a short spacing To
effectively simulate this a variable grid spacing should be used
with reduced node grid spacing at trench locations to eliminate
distortion The computer simulation shows that the slurry trench
could direct flow in the landfill area in a southeasterly direction
and away from endangered wells In addition it would reduce
upgradient infiltration from the stream into the landfill This
measure would prevent leachate from spreading beyond this carrier to
possibly contaminate neighboring wells
The combination of both the slurry wall and impermeable cover
would be ideal measures to minimize generation of leachate and to
stop its spread to neighboring wells The slurry wall without
recharge over it or the landfill is simulated in Fig 31 This
indicates a lower water table tnan eliminating the recharge to the
landfill The slurry wall has blocked upgradient ground-water flow
at its location to the landfill
80
Legend
landfill limit -laquo- j -laquobull excava t ion ^^- stream
copy WNWNEECSESC monitoring well locations
= = = unimproved road ssi slurry wall
f e e t
Fig 30 Slurry Wall
81
Legend
landfill limit j- j- J- excavat ion x-v^gt- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road s==s slurry wall
400
feet
Fig 31 Slurry Wall without Recharge Over It or Landfill
82
An intercepting drainage trench is considered next If a trench
was excavated to a 30 ft depth in the outwash material extensive
shoring would be required In addition difficulties would arise
when the trench was excavated below the waterline Tne trench would
be sloped to provide drainage and backfilled with a highly pervious
material to intercept and divert leacnate locally a conouit which
is perforated on the top to allow infiltration and unperforated on
its lower perimeter to permit continuous drainage to the collection
treatment center would be installed on the bottom of the graded
trench The difficulties involved in excavating below the water
table ano shoring the sidewalls to permit implacement of a drainage
conduit at a 30 foot depth make this option increasingly infeasible
83
Conclusions and Recommendations
The location of the South Kingstown landfill in permeable sand
and gravel glacial outwash material (107 ftday) combined with the
high hydraulic gradient across the landfill area (20 ft1600 ft)
creates a high potential for ground-water contamination to occur
This is intensified because refuse nas been placed below the water
table The low hydraulic conductivity of the compacted refuse (1
ftday) and the excavated area to the west of Rose Hill Road have
both contributed to modifying the original southeasterly flow
pattern These modifications have created a ground-water divide in
the landfill at approximately the western third section Tnis
results in approximately 13 of the leachate flow from the landfill
or 63 gpm flowing in a southwesterly direction and 23 or 129
gpm flows in a southeasterly direction Infiltration from
precipitation recnarge over the landfill (up to 9Upound) and from tne
upgradient stream during low water-table periods provides tne
necessary influx into the landfill Evidence of contamination is
clearly seen on both the east and west sides of the landfill which
reinforces the previously stated flow patterns
Of the several remedial measures reviewed the contouring and
grading of the landfill topcover and drainage swale provides the
most immediate protection The topcover has been graded mulched
and seeded to provide a low runoff slope generally to the east
The drainage swale on the left side of the landfill has improperly
graded sections which should be corrected Its northern section
could be drained into the northern sections swale and the southern
84
section drained to the southeastern section of the landfill Tne
point of the drainage swale which divides the northern drainage
swale from the southern one should be determined by a field survey
Cost is a major contributing factor when determining which
remedial measure is to be applied to the given situation For the
purpose of this report cost estimates are not presented but rather
the effectiveness and feasibility of the remedial measures are tne
primary considerations As was reviewed and simulated in the
computer models the slurry trench and impermeable cover over the
landfill are two viable options that would effectively provide
protection to the domestic supply wells in tne vicinity The
impermeable cover would eliminate precipitation recharge into tne
landfill yet drop the water table only a few feet due to upgradient
infiltration from the stream This would decrease the hydraulic
gradient thus diminishing the potential for a contaminant outflow to
surrounding wells The supply well of primary concern is one to the
west of Rose Hi l l Road marked well D on Fig 2 If contamination
occurs in this well the most effective measure would be to block
off leachate flow in this direction by installing a bentonite slurry
trench at the location indicated previously This would effectively
prevent leachate flow in the westerly direction and diverts it to a
more southeasterly direction In addition the slurry trench
precludes infiltration flow into the landfill from the upgradient
stream
85
Tnis report has effectively reviewed tne original ana existing
flow conditions and contaminant levels in the vicinity of the Rose
Hill landfill The purpose was to provide an understanding of
ground-water contamination patterns and study possiole remedial
measures
86lt
Appendix A
Precipitation Records
Monthly normal precipitation 1941 -197O
i$l Total monthly precipitation
KINGSTON RI
14
ia
^JO T I bullbullL
pound 111 laquobull
4
a
n
-
^
-
-
KS1JAN
^Ii R3 HB MAR
1
1 APR MAY
1
1 JUN
1981
JUL
-bullraquolaquo H
AUO SEP
K3~~f$s bull
_imdash
i1S 1
OCf NOV OtC
171 1 iI1
JAN HB MAR APR MAY
198
Fig 32 Precipitation Record
- - - -
IM 1 MtvJrflgtlgt c ortli-A t lUN I r nraquo rl - -
gt|MO CLIMATOLOQICAL OUSERV ATIONshyr-r bull JK gt raquo - 1
i5fWA I VAPOR Al IOH -bull AIM If MPCRATUM bullF 0 riccipn AT ION UNO IlMf
bull 14 H 14 H mdash Vshy ADDITIONAL DATA IfUAlUS OATt 1 bull raquof bull bull 1 ta
14 Hw rlaquo4 w bullbull bull 1 114 1mdash4 (llrl 1 1 1fl Hll
0 kmdash
Mraquo M4 raquo i T i 4 bullraquo-laquobull i i
Lgt f 1 21 S 1 Hbull - - bullbull -
ltJL 1 2 01 - - _ _ 1
mdash
-
1 12 _ Q I
mdash shy
mdash 4 (C ( - - fVi 1 - 0
1 (1
^ 1
Vvraquolaquo IJ1^ raquo CP O 3L 1 Z - i bull j-t-J
1 J
LH Vb T n 0
1 gt fl oo O ~l 2 L - bull 1 P )laquo jn iP IP - OOI L5L mdash shy
-t 84 ^(^^ ^fi P i flja 0 JO II 10 tl tcgt 7 J IV wllaquo
h l2L bull 0 lt -_ shy
-id VJ lt 3C 2 ft OOL -mdash
U 71 C1 Sr 2 13 2 nl JLJraquopound HP r M ltf1- (
IMe 2 ii O It
n jlt dl 1 1 bull o o-il ST i 1 i 25 2-x-1
-
ri
i tlL O mdash gtbull bullgtlt 1ft -o- is Oil So iJK 2-io otv u 31 fil loi 2 il Oll it Of wr is i1raquo -iZ 1 deg|0 01
M IT So - mdash
- 13 1 CT mdash i - mdash 21
shy
Tl Ci av ZUll IMT 0 IM Pe v _ 1) T) S) ii3( dlt Ii 2 lt^2 II li- S1 riivi To 7HX lt3lO 14 ^2- iTi I li 011 -- - -i -^IS no 5^ or i | T Jift laquoV OoH bullla It Va iCO mdash L OIL 11 bullvf poundgtpound lS_ flv oh P-lfe 1 poif _ shy11 IB kl (4 itlaquoT lamp llt0 oot^
mdash -n
It T1 |ir( L1 HI 2 0 oil
U 1M ft go C ICf^ -^2 Z laquo-|o
11 it 5 bulln - TO o abull Li u-i IT1 -- Iw O ltM (I bullbull bdquo-I(K 1mdash -tilltLlA ttfe
i Dgt ac -- U 44 4 11 1 1- ytd i i_i J-K 0 i if -i i i V t Wl raquoOHM 1-1 US D C P A R T M f N T OF COMMfRCE t 4 1 IUII 1 1 ^~) mdash
llaquo- Hi NC bull bullh bull bullJL^V HBl CO 00
11
)jLsVyr^gturv
^ | TKu
|-_t_ bull(
IIMgt I I Mt|UU III- II 11
PNECIPITATIOH
I 1 1 IMX
IMO
bull llfclaquo I UCIUKI) Ur C V A r U M A AHO CLIMATOUOCICAL OBitH
E V A F O R A T I C r i Jttffl laquo amp hMIlaquoJllaquoJIIlaquoBgt
DATE AOOITIOMAL DAIAKMAKk M
bullraquobullmdashlaquo
tp 01 (1 Of Ll OOI ooo
0^1 o-i 10 tl |00 102
OC (1 13 Ofl
it i rc DS os an
(1 SV o
Ul 010
(ISl 101 I on
130
II 5= Otl
ss lt 001 (IK Ml
jt il HIT
7 it
ow Wo 17 Top 2-01 OIO
(0 oov zi oot
u CO ^A 0 to Zoi CLflS
bull50 01 ljtj
nshy 5H LO OIt
50121 IVO QJO
14 Co Ho LO Hl ^pound Jl 1
ltM ool fllc
H Tl 01 II
11 11 Q1
iH OIO
HO 2 llaquol 11 II
lifc
IV-IIM ul OIPAITHINT or COHMIICC NOAA
NAtlOHAL gtIATnlaquoll raquotraquoVlClaquo CD
r~
All TCUMMATUNI ^V UII rgt ITmi 1 Cwphu Obic i gtn t ngir-H 30
rilCiriTATIOH
JJ T I rTJ-rimdashr-iramj|MP CLmATOLOQ
laquolaquo jftilCiii bullIHO
Oi1l ADOITIOHAL DAIAlllu
Ilf4ft
Sii1
(1 2 IO OO
Hl ii SO
us OIM
Q^L
a A3 Hi SZ Sf^ bull 12J2
HI Z-SF OOl 1C t HM IA H ICP fiJA
OOl 10 (310 sn 310
if HI (0 ^01
bullit SO 28H poundJ1 11 006
14 35 TX oon II (bull2 it zr II c-S
rr Zll lo 31 OP an 31 a 31 oor
CSW O-ll Si CC Of 011
Oll _ I |ft
00
u i oerraquolaquoTMiMr of c NOAA
NATIONAL K C A T N C M SCMVlCC
TC^S lk)oiVroTJA
TETT I 7X
1raquolaquolaquo 4 bdquo ir lt er ni I^OV ltqgl j--^ TQ
MICiriTAllOH ITIND
D|mdash
b5NO ctiUATOtoiCAL oeit^
OATI AOOITIOMAL OATAVlHAtt
0-tt
Mlaquoh bullbullbull- rshy laquo
I- ltltriu HI I 4 bulllaquobullbull1
Zii
30 Dfellt otvt
at HA
OOI
62
iJ_S2 HI if
bull- 20 SI 2i So
So
VVfr
OSfc
I (
Jtlt
3aoi
r j -bull ie MA
Irill iiol
in^ 14
Mo
Zll
214
21 1P
00-i
bulliron
17
bullr
11 i ir- I J Ktf^c
US D E P A R T M E N T OF COuMEDCC I | C gt A A
K AIlaquo Ttupf lATuit r
|SlVi AlJ PIICIPITATION
oJud (El
VIM i Uraquo
MIND E
EVAPORATIOH flnrft bull A ftufiifccdll
KECORO OF eVAPllHAtlil bull I CLIHATOLOOCAL OBSERVA ^Hij
14 MM A_M AOOIIIONAL DATA11 MAIM
Mr bullH Oo|
M Si lift
bull221 IHI
ZS Ji 40 IZV
icr KS I
HZ 111
bullT 21
loA UK JA IP
v^ ft
1M 2Sshy IT Tl
71 V |
i I 31 1deg a
uty^ U bull3
ons 1 CiO TxX
HHO (10
3H 19 12 10 IP
raquo3H raquo | 5t io
OP OIT
14
vO UI Of PANTMINI Or COMMCRCf MM O A A
F ngt TIHH
iiicffwiffc 4 rJ (TIM bull Cempltit Obitittiio
AIlaquo TIMHIATUM PHICinTATION I V A f OK ATlPrl
OATI ADDITIONAL DATA KMAlIt
U4laquo4 +
03H Ji
10
rc a 1 16 oi ii
tiiy 10
OI
II i23 or o 13 -y~ou HO
II 3V III i 3 t
V laquop oot
OM1 SS ne
T an -i IP
Olt zr LTV
3T 001
a -11 2T
10 an 31
-1 raquo 131 UP 3H lf 14 Lpoundshy
it 14 30
IS
Ui O I P A K T M f H T OP COWlf ICfM O A A
NATJONAI V C A T M C n f t K M V l C K
bullbullbullbullbullshy -2 o AIlaquo TIMMRATUM f fKICIPITATIOH
OATI poundt- MMINMAL DATAk
ZP 51 lo icr
011 111
OoT IHf
Ut 003 am
3o 13 ao
4A X 05shy
H4 i IjJyiV131 ooc js
IH oi 01 tL 18 13 a
No 11-7
rivgtp OO| M Hi 03 01
It 12
bull I 41 bull7119 14 ^^ raquo 31 15 lampk n M ho i
Jo -j-
-J
I
Ml H^ I _
amp2ampUi^= LS 0 S 0-f bullTTT
-Vmdash gt U_ bull 1 rOHM I- 11 OI OCPARTMlNT OF COMM(NCC
HO NATIONAL W f A T M f H ftfraquoVlCI
98
Appendix B
Boring Logs
99
X iHECT 1 ff 2
OAT American Drilling amp Bor ini I Co Inc
wo WATH smn EAST PR ov IDENC E ft 1 Town of South Kingstown South K ngstown R I MOLENO X-J
TC 100 RCSS bull ujrMonitorinq Well Installation | South Kinqjtown R I UNC a STA Pf KXICCTHJ LOC ATK3N
bull cfrserrr TO above S MPLES S FNTTO _ _ |laquolaquor A-109 SURF ELEV RE PORTSEr
GROUND WATER O6SE RVATC MS 1 CDREraquolaquo m-T nn75 laquo A 256 - 20 mdash Hew y
Instolled 32ofT-l2 PV C - JO- COMPUTE 111275 K toia 3- I-WI 1-38 TOTAL MRS bdquo10 screen BORING FCACUAM J K lanq MAI rraquo HomnwWI 300 140 IampPCCrc Mamlaquor Fall 24 30 lampaaiona SOLS ENGR
LOCATION OF BORING H ONITOKING WELL
Coung Samplt Tjp Blow per 6 Manure SOU IDENTIFICATION Strata SAMPLE ^^^yV Bloot
foot
Otptni
From- To
el
l
on Sampler
0-6 1 -6-13 12-18
Dentity or
Conmt j
Chang Remark include colo^ graaation Type of tod lie Rao-coMr type condition nordshynetiDntotf time leamt and tie No Pen Rtlt
2 No top sample 5 12
1 loamy fine sand
bull)^ 40 30 36
5- 616 0 23 20 16
noist iense
Brown fine to coarse SAND some fine to coarse gravel Trace silt
^
1 18 18
36 8-0shy57 40 30 V 35
|0-||-6 D 14 24 20 Srown medium to coarse SAND Some fine gravel cobbles
7 IRshy 16
27 75 37 3
IS- I- D 5 14 16 3bull
ISshy 15
42 50 I9--0shy50 65 20-2ll-6 D 9 23 26 bull Jrown fine to coarse SAND Tbullwshy 1Z 75 90
22-0 Trace silt trace fine gravel
124 120 74 60 52 41
7S-ltlaquoil-A DX 71 16 13 wet very dense
Gray-brown fine to coarse SANC Some fine to coarse gravel little silt
H IR u
40 30--0
3C-30-IO
3l4-334
334-3314
38 4-434
D
c
C
C
7 IflO
94 6
we tr j
y se
ft irox
30MOshy
31 -4shy
Gray-brown fine to coarse SAND Trace silt
Gray-brown fine SAND some lilt trace fine gravel
Too of Rock 31 -4shy
Gray-pink GRANITE
6 7
amp
CJ
IltJ A
60
601
IQ mdash
2(
4
5 i Hard
ft 5ome seams bull
GROUND SURFACE TO J 4 U3CD_ ^JVrf bullbull( tutu t to 4o 4 SampM Type Proportion UMd MOB Wtx 3 OfaM on 2OD Sampler SUMMARY-
OOry CCartd WltWen4 Hoc OlolO Canmonieraquoi Don any CoKeem CarMWncy Earm Barrlaquoj 11 14
UPgtUnOigtturod Piuon trite (Oto20dego 0-Kgt Loei it 0-4 Sait 3O+Hofd Rock Corng 14 Kgt-30 laquo4 0 rte 4-8 MSHM Samplet TPTtitPit Ai Auger Vvanefett tarn 2Olo39 3O-M Owlt n laquo-lS Strlf rinit nn v 1
UTiUndlshffbed ThrMOll and bull 33to9O 5O Very 0laquo nraquoe 19-30 V-3trraquof - | OLE NO X-l
TOVH rim - iA it raquotoraquo
100
SHEET 2 o_L
WO WATEt STUET [AST ft OVIDENC pound a i American Drilling amp Bor ing Co Inc
MCLl WQ X- 1 Tt AOORCSS i
LIME A STA KXICCTMJ tuf same as 1 | tame as i LOCATION
W PORTSEf mo OB nj urt eflaquo T
illtPLES S
P
CVTTO nlaquo mun orv
^s f^ Tin i GRCVMO WATER OBSERVATONS CASING SAMPLER CORE BAR
START Typi COMPUTE tome at 1 same aiH
TOTAL MRS BORIMG FOR CMAN n bull IT INSPECTOR SOILS EMM
LOCATION OF BORING u HfVJTneTfi UFI _
8
Counf Blo-t
foot
Dtpllo
From To
0( on SampMr
0-6 f 6-IZ
Moittir
Oonuty or
Contilt
Strata Ctnngc
SOIL OCNTiriCATION Rtmorkt ineHifl cotot grqdotion Typlaquo of Mil etc Roo-axtrPlaquo condition Mrdshynlaquot Drog tun ttomt end tic
SAMPLE
No Ptfl RfK
434-4o4 c
approx 7 minj
per toot 454
Gray pink GRANITE Hard Fairly solid core
lt_4 24
Bottom of Boring 45 -4
-
~
bull 1
GROUND Sorrow Tye
SURHCZ 10
bull OiOry CgtCord WWothod UPUnditiurMd Piston TPlaquoTtraquotPtt AtAuotr VVor
UTltUndinrvd TTMMO bull bulltat
iivnPilaquo(onioni Uraquot4
me OioiOItttt laquoraquo20
wmt Z0ie33
and 361090
c M
C1 5 Si
-SOshy
ASING
IOtgtWtigt bullnlot Dn 10 Loci M Mod 04 SO Dm 1shy Viry 0laquo
s _
TMEN 0 hMl on 200 SoiTBUr laquoity ConcMMt Conorawncy gtbull 0-4 Sort 30shym 4-B MStlfl M BH9 Strtf bull ts-so v-swt bull
t-HOrt Ear Bern RoetCorrt
i ^^^^^ bull
-[MOLE no x-i
101
raquoMEC rAmerican Drilling amp Bor in g Co Inc 1 ofj_ DATE wo WATlaquo smn UST Plaquo IOIDCNC j laquo i
Town of South Kingstown South Kingstown 8 MOLE MO Jlt Z TC rx MCS3
rtprr uAurMonitorina Well Initollation | South KinqitowrxRI UNC A STA P KATIOM ME POCT ^rwT TO above I OFFSZT
uD^r laquorlaquorTTO 6 -109 suw tLEv Sgt louffJOCNO
0 tj Tlmlaquo WOUND WATER 06SCRVATC US gtW Rsdl SING SAM^EH CORE BAH
26 ^_ 12 $TAlaquoT UL 2Z2i Ji r TTP NW ltA sr IJZC Z5 CCOMPLETE
SitLO 3 I-3B- 1-38 TOTAL MAS 41 BOAINO FOACMAN JK1 ana nf ni n MonwwWl 300^ 140 BIT bullK^CT
gttonvrar Foil J^laquo 30mdash Diamond SOOJIEMGM
IE HFII
iCaunq SampM Trplaquo BMMtpw6 UOIIIK- SOIL DCMTIFKATION Siraia SAUPLE Blow DlaquoPIAraquo of on SompMr HtmorU mcJuo cotes gradation Type of Dwuily
pw or CXang writK Roel-eolorlyp condition tvort-From- To Vfoot 0-6 f 6-2 12-18 Coniitt egt rwtiOnAngtimt wamaondtte No Praquon Rtlt
2 Brown fine SAND little silt 2 2-0shy5 15 18 moist Browi fin to coarse SAND 18 5- 6-6 0 14 25 27 vlaquo Troc fin aravel | 25 wy Ifl 11
dlt tns 35 40 38 moist n in-il-i Lgt U 15 18 ie is li1 Irl IS 31 I2-0
~~43 1
A) Jrown coars to medium SAI MD 48 moist Little fine to coarse gravel
|5-IA-Xlaquo 14 47 41 fn D laquo y Little silt rrqa coarse sane 3 18 I1
68 In IS 44 32 34
n ^n-^i-A- w 2o 19 29 wet 4 la -59 lens ltfO no
25-0 2amp bulllaquo- 77 c BOULDER r[ 4 i
27-0 5X ~W 24 24 bullWar- 5 Ifl irown tine to coarse SAND some
dens 29-0- Fine-coars gravel trace silt
30-3I oxx 30 32 30 moist irown -gray fine SANDiom e 6 l rr Vlaquoy 31 -0 silt trace fine oroveTILL
Bottom of Boring 31 -ampbull shyBent casing -pulled out and moved over 4 - washed amp tJrovlaquo casing to 30 -Installed 3C gtof 1-12- PVC - 10 screen
WOUND SUraquoraquofCE TO 3pound 1 yijfD MW t ASIMC TMCJ laquo olaquorod -bor of borina
SomoU T]Fplaquo ProigtuliOraquoH UMd MIOtgtWLx3Orolt lon2OASanlaquoMr SUUMARY-D=Dry CCorad Wlaquoworaquonraquod bullact OiaiO CanM gnMM Daonty CIMIH Caamraquoci EffW 8or^ 2pt
UPiUnairurMd Pition Itnt laquoM2O O- O UKraquolaquo 0-4 Soft 3O-hHard Roelaquo Corrig o- JO M0mlaquo 4-8 MSNff SOTipM 1 p^ 3O-9O OwgtM bull-IS Slid
TPlaquoTraquojraquoPit AAugtr ViVon mini tamt 20to39 UTtundiifir6d TrwMOtf and JSloSO 50-raquobull Vary 0nlaquo [HOLE NO x-2 B-3O V-3Mf lev rim - IAIT raquosectlaquoraquo
102
300 iu 24
1 UMnii ffi 140 laquo 30
CA1INC tf
gt taWCTf
bull 0gtlaquo i R Cook Jr_ R Millineton1 Wttn
I~
1 VAMtl CtMG
1 W HO-t MO
1 Oraquo 1 laquo0~ twt
L 1 laquo-raquo VfcM^lf [wlaquoraquoCI ^ ^ K3Ot III laquo
0-LS D
5-65 D
LlQ 10-115 D
15-16 Tgt
Lraquo 70-51 n
25-26 D
F
I O-O Ci
A Allstate Drill ins Co vi o i
PROVIDING R 1bull raquoraquo uvraquonn~ N M O M I T O P I N G HE1 _^lt -^ PI-Traquo UJU
CUM Town of South Kineraquotown raquoraquo 1 1TA maoer Propolaquolaquod Sit for Slude Disposal nltn
laquo V-449 iampAAtut i a 138 ort STI bull r 42777 CtOuMO IKVtllON
Cill bdquo 258 DA II MN ru 42777 rilaquolaquodO laquoraquoTti rum 1911
AU1TATI
MMUI1 raquolaquogtlaquolaquo laquoKiO itXHHKraquoriOi of sous MUAHI nMTKlion Ot CMlaquoMC|kOraquort tl CO~VH DXltgt raquomlaquo laquotf IMi COIOI C4l II I 1raquo gtlaquo^ Oraquo 1Ol rC t Xgttgt VtfKOe Craquo Mi 1 ft liMraquoK laquo0^tlaquot nfgt
1-2-1 10 TOP SOIL FINE LIGHT BROWN SAND traclaquo of ilt
16-31-17
22-24-21 100 FINE TO MEDIUM LIGHT GRAY SAND trace of fine gravlaquol and raquopoundLt
lfl-37-34 150 LIGHT BROWN FINE TO MEDIUM SAND little poundinlaquo gravel
21-17-15 200 MEDIUM TO COARSE SAND bullomc fine gravel
12-4-10
265
Observation well installed
NOTE No casing blows taktn
bullbull B-23 ow
^w^ 265 I raquo bull raquolaquo bull I W
11 laquot gtbullraquo Vlaquo 14 W gt_ c-shyji bull alaquo bull jraquo VI laquoHshyw bullbull m raquobullbull D-6 raquo Mshy
bull bull laquo Vshy
1
bull bull
I
103
MAMMII Allstate Drilling Co ulaquorr 1 or 1 FftOVIOCKZ H L traquolS mTArm^S MONITOR NR WEL
VNO wr3JJO__raquoraquou_24__ HCU MO P-74 n iu riBwi Town of Slt7H^ Xirpin
mdash^ laquo0J P 1 1 bull ^n^ciit^o TVlaquow^laquott1 bullraquoit wt 140 nu 30 olaquor fBu lkv Waste Disposal Arcai
MUTAH a V-449 R Cook Jr UMlaquoiigti D 1 38 0t| raquoIJ raquo 5277 rlaquo SUMO luvlaquorv-laquow
mdash 5277 fipe -raquoT pfpm 150
H MCIO IMNTlXAflON Of SOU t(kAIlaquoS rrn 0-laquoraquo
5 -SF 01 w in laquobull -raquo ^ lit
D 1-2-2 TOP SOIL V-1-oraquo
15 IPbull FINE TO MEDIUM LIGHT GRAY SAND AND GRAVEL
5-65 D 37-27-35 some silt
10-11 D 20-14-18
15-165 D i 17-14-14 155
BROWN COARSE TO MEDIUM SAND little fine to coarse gravel trace of silt
20-211 D 4-4-2
230 GRAY BROWN VERY FINE SAND
25-26J D 7-8-9 AND SILT 265 fvarvedl
Observation well installed
NOTE No casing blows taken
wta 10 n uuraquo c^imdashbull IgtM laquolaquobull- B-24 ow ~ 14 ltfc laquoraquobull vlaquo^ M laquobull r O 0 fmtt bull W-L 26 5
-0- CgtCmdashgt bull laquolaquobull mdash laquo 1 - raquoraquo 1 gt 1laquo bull 1 gtraquor to bull mdashbull bull bull bulllaquo I t l~laquo 1lt Uraquo mdashbull ) bull 1 gtbull ft 0~ H laquoy bullM ta bull -IN la laquobull OPUM bull($ IMI
mdash H raquo laquo-bull
104
Appendix C
Calibration of Specific Conductance Meters
105
Specific conductance measurements were made using a beckman RB
338 temperature compensating meter and a YSI rtooel 33 salinity
conductivity temperature meter The YSI meter is not
temperature correcting A formula to compensate for temperature
differences to standardize YSI measurements was used (21)
A long probe for the Beckman meter was used to measure conductivity
in the wells Differences in conductivity between the YSI ana
Beckman meters and the Beckman short and long probes exist These
were calibrated in the laboratory using 001 N and 01 N KC1
solutions Values presented are Beckman short probe values The
Beckman long probe values were reduced by 76 and tne YSI values
were multiplied by 11 to adjust to Beckman short probe values The
YSI meter was used in the latter phases of the study for the
stream contamination due to the greater accuracy of the dial readout
scale
Table 7 Specific Conductance Meter Calibration Table
Concentration (KCL) 0001N 001N
Specific Beckman short 145 143 143 1247 1245 12GO
Conductances Beckman long 190 191 188 1639 1650 1665
umhocm 9 25 C YSI 132 131 128 1131 1140 1150
average values Beckman shortBeckman long = 075
Beckman shortYSI = 11
106
Appendix D
Computer program Flow Chart
107
F1g 33 Computer Program Flow Chart-
1TpoundR MAP TCO
NEWPER
WEWSTP CZAX
HEWIT TRANS TCOF ROW COLUMN
Yes
Yes
108 The following is a description of the USGS two-dimensional computer
program Iterative Digital Model for Aquifer Evaluation updated
December 1972 by P C Trescott The program written in Fortran
consists of a MAIN program and six subprograms or subroutines which
themselves are organized into subprogram sections The subroutines and
their sections are listed below
MAIN Program
DATAIN (subroutine) COEF ITER (section) CLAY MAP TRANS NEWPER TCOF
ETRATE COMPUT STORAG
NEWSTP LEAKAG NEWIT1 NEWITO CHECK ROW CWRITE COLUMN STEADY PRNTA OUTPUT DRY BLOCK DATA
The program begins in the MAIN program which controls the sequence
of passage to the subroutines Sequential steps are described in the
program as shown in the flow chart of Fig 32 Emphasis is placed on the
steady state confined aquifer case as applied in this study First data
input is read in the DATAIN subroutine This data includes transmissivities
or permeabilities starting heads storage coefficients and grid spacings
Nodal transmissivity values are then computed for the water-table problem
in the TRANS section (COEF subroutine) This procedure is necessary here
because the subsequent routine for computing iteration parameters (ITER)
keys on nodal transmissivity values which would not have been input to
the water-table problem In the water-table option these would have been
109
computed from given bedrock and water-table elevations to obtain the
saturated thickness component of the transmissivity calculation In this
study water-table option was not used and the transmissivity values were
input directly The program then passes to the ITER section (DATAIN
subroutine) to compute the iteration parameters which expediate or even
cause convergence Next the MAP section (DATAIN subroutine) is utilized
to initialize data for an alphanumeric map if this was requested in the
input options Transmissivities are then computed for the confined
(artesian) aquifer case (water table not specified with input options)
in the TCOF section (COEF subroutine) These coefficients are harmonic
mean values of adjacent nodal transmissivities weighted by grid sizes
Time parameters and pumping data for a new pumping period are then read
in the NEWPER section (DATAIN subroutine) followed by entry into the
NEWSTP section (COMPUT subroutine) which calculates the size of the
time step Leakage coefficients (hydraulic conductivity of the confining
bed divided by confining bed thickness) are next computed in the CLAY
section (COEF subroutine) if leakage was specified in the input data
which was used in this study
A new iteration is then initiated in sections NEWITO (COMPUT
subroutine) NEWITO saves the current head values and compares them to
the updated head values for determining closure This is followed by
nodal transmissivity values being computed for the water table or water-
table artesian conversion problem Transmissivity coefficients are then
computed for the water-table problem in TCOF (COEF subroutine) Total
head values are then computed with the alternating direction implicit
procedure using the Thomas algorithim first along rows in the ROW section
110 and then along columns in the COLUMN section both in the COMPUT subroutine
Then if a solution is not obtained (because the error criteria for
closure is not satisfied) the MAIN program branches back to NEWIT1 subshy
sequent sections TRANS TCOF ROW and COLUMN repeatedly until a
solution at the particular time step is achieved NEWIT1 increments the
iteration counter and is immediately followed by NEWITO The program then
moves to the STEADY section of the COMPUT subroutine to check if the
closure criteria for steady state has been satisfied Output is then
printed in the OUTPUT section of COMPUT if steady state has been reached
or if the particular time step is designated for output
The program then branches back to NEWSTP (COMPUT subroutine) and
moves through the subsequent routines until the last time step in the
pumping period is reached Output is then promoted in the DRY section
of COMPUT if specified in input data If the last pumping period in
the problem has not been reached the program branches back to the
NEWPER section and moves again through subsequent sections otherwise
the program will terminate or start a new problem if one follows
This study was simulated as a steady state problem which can be
simulated by setting the storage coefficient of the aquifer and the
specific storage of the confining bed to zero and using one time step
of any length
111
Appendix E
Computer Data Sheets
RGSEA
10 ROSE HILL LANDFILL MODEL 20 30 40 LEAKAGE 50 60 70 CHECK 80 90 100 HEAD 110 120 1 23 IQ 100 5 001 37E-OU 0 130 100 001 0 0 1 4 0 - 1 - 1 1 - 1 - 1 i i i i i i 1
ISO 1 10 0 1547E-05 01 10 1 1 160 04642 200 200 1 1 i it
1QO 190
CARDS I THROUGH 19 - CODING SHEET
CHEAD
100 110 120 130 131 132 140 141 142 150 151 152 160 161 162 163 164 165 170 171 172 173 174 175 176 177 178 179 1BO 101 190 191 192
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 539
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 58
25
25
25
25
25
25 621
25
25
25
25
25 662
25 25
25
CARD SET 2 - STARTING HEAD MATRIX (FT)
193 194 IVb 196 197 190 200 201 202 210 211 212 220 221 222 223 bull 224 225 230 231 232 233 234 235 236 237 23B 239 240 241 250 251 252 253 254 255
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 23 25 25 25 25 25
25 25 - 25 25 25 25 25 25 25 25 25- 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 - 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25
25 25
25
25 25
25 25
25 25
25
25 25
25
25 25
25
25
25
25 25
25 25
25
25 25
25 25
25 25
25
25
25 25
25
25 25
CARD SET 2 - STARTING HEAD MATRIX (FT) - continued
STORC 1512 FRI 19 FEB 82
100 110 -1 -1 - 1 - 1 0 0 120 130 140 ISO 160 170 100 190 200 210 220 230 240 230 251 260 261 262 263 270 271
CARD SET 3 - STORAGE COEFFICENT
LEAK
100 110 120 02 130 _ 18 02
I ltu 18140 025 150 02015015015 19 deg25
02 160 022 bull-laquo- J1 5 j 1 z laquo- l^
170 015 180 016 laquo02
190 016 OE025
200 02504019022021025 2 5 i S lt03 0252i2 n
230 030 deg23 deg2 deg2 deg2 -02023023 240 022 250 022025025 02
027043 013025
30() 025025025 310 025031 320 024025
CARD SET 5 - AREA OF STEAMBEDAREA OF NODE
120
Appendix F
Bibliography
121 BIBLIOGRAPHY
1 Agpar MA and 0 Langmuir Ground-Water Pollution Potential of a Landfill Above tne Water Table Groundwater V 9 No 6 1971 pp 76-96
2 Allen William B Hahn GW and RA Brackley Availability of Ground Water Upper Pawcatuck River Basin Rhode Island USGS US Government Printing-office GS 66-624 19bb
3 Annual Book of ASTM Standards Part 31 Open Channel Flow Measurement of Water and Waste Water by Weirs D 2034-68 1975
4 Annual Book of ASTM Standards Part 19 Infiltration Rate of Soils in Field Using Double-Ring Infiltrameters D 3385-75 1975
5 Baeaecner MJ and W BacK Hyarogeological Processes and Chemical Reactions of a Landfill Ground Water V 17 no 5 1979 pp 429-437
6 Beck WW Dunn AL and Grover H Emrich Leachate Quality Improvements After Top Sealing1 8th SHwRD MERL Symposium 1982
7 Beckman WK Transient Modeling For Estimating Sustained Aauifer Yield master thesis presented to the University of Rhode Island Kingston RI 1978
8 Bhattacharya PK and HP Patra Direct Current Geoelectric Sounding Elsevier Publishing Co New York 1968 135 p
9 Bouwer H Ground Water Hydrology McGraw-Hill Book Co New Yoric 1978 p 378
10 Braids 0 Cocozza pound Fenn D Isbister J Rous P and B Yarc Procedures Manual for Ground Water Monitoring at Solid Waste Disposal Facilities Environmental Protection Agency530SW-611 Cincinnati Ohio 1977
11 Cartwright K and MR McComas Geophysical Surveys in the Vicinity of Sanitary Landfills in Northeastern Illinois Groundwater V 6 no 5 1968 pp 23-30
12 Cartwright K and Fd Sherman Jr Electrical Earth Resistivity Surveying in Landfill Investigations Reprinted from Proceedings of ohe lOtn Annual Engineering and Soils Engineering Symposium Moscow Idaho 1972
122 13 Clark TP Survey of Ground-Water Protection Methods for
Illinois Landfills Groundwater V 13 no 4 1975 pp 321-331
14 Dunne T and LB Leapold Water in Environmental Planning WH Freeman and Company San Francisco 1978
15 Faro DG Upgrading Hazardous Waste Disposal Sites Remedial Approaches US Environmental Protection Agency500SW-677 Cincinnati Onio 1978
16 Fenn DG Hanley KJ and TV Degeare Use of the Water Balance Method for Predicting Leachate Generation From Solia Waste Disposal Sites US Environmental Protection Agency530SW-lfa8 Cincinnati Ohio 1975
17 Geisser 0 An Electric Analog and Digital Computer Model of the Chipuxet Ground Water^ Aquifer Kingston Rhode Island master thesis presented to the University of Rhode Island Kingston RI 1975
18 Hahn GW Groundwater Map of the Narragansett Pier Quadrangle Rhode Island Rhode Island Water Resources Coordinating Board GWM 5 1959
19 Hemsley William T Koster C Wallace Remedial Technique of Controlling and Treating Low Volume Leachate Discharge USEPA National Conference on Management of Uncontrolled Hazardous Waste Sites Oct 1980
20 Hughes GM RA Landon and RN Farvolden Hydrogeology of Solid Waste Disposal Sites in Northeastern Illinois Final Report to US Environmental Protection Agency PUD SW-l^d Cincinnati Ohio 1971
21 Keller GV and FC Frischknecht Electrical Methods in Geophysical Prospecting Pergamon Press New YorK NY 19bb
22 Kelly WE West Kingston Landfill An Evaluation of Its Effect on Ground-Water Quality Rnoae Island Water Resources Board Water Information Series Report 1975
23 Kelly WE Geoelectric Sounding for Delineating Ground-Water Contamination Groundwater V 14 No 1 1976 pp fa-10
24 Kelly WE Ground-Water Pollution Near a Landfill ASCE Environmental Engineering Division Journal V 10 No EE6 Dec 19b pp nay-nyy
25 Kelly WE personal communication January 1982
123
26 Kelly WE and OW Urish A Study of the Effects of Salt Storage Practices on Surface ana Ground Water Quality in Rhode Island NTIS FHWA-RI-RD-8001 1981 54 p
27 Kimmel GE and OC Braids Leachate Plumes in a Highly Permeable Aauifer Groundwater y 12 no 6 1974 pp 388-393
28 Klefstaa G Senalein LVA ana RC Palmauist Limitations of the Electrical Resistivity Method in Landfill Investigations Groundwater V 13 No 5 1975 pp 418-427
29 Landon RA Application of Hydrogeology to the Selection of Refuse Disposal Sites Groundwater V 7 no b 19b9 pp 9-13
30 Lang SM Bierschenk WH ana WB Allen 1960 Hyaraulic Characteristics of Glacial Outwash in Rhode Island Rhode Islana Water Resources Coordinating Board Bulletin No 3
31 LeGrand HE Patterns of Contaminated Zones of Water in the Ground Water Resources Research v 1 No 1 1965
32 Palmauist R and L Sendlein The Configuration of Contamination Enclaves from Refuse Disposal Sites on Floodplains Grouna Water v 13 no 2 1975 pp 167-181
33 Pinder GF A Digital Model for Aauifer Evaluation Techniaues of Water Resources Investigations of the US Geological Survey Bk 7 Cl 1970
34 Purushattam D Tamxe GR and CM Stoffel Leachate Production at Sanitary Landfill Sites ASCE Environmental Engineering Division Journal V 103 no EE 6 Dec1977 pp 981-988
35 Remson I Fungaroli AA ana AW Lawrence Water Movement in an Unsaturated Sanitary Landfill ASCE Sanitary Engineering Division Journal v 94 no SA2 April1968 pp 307-316
36 Rosenshien JS Gouthier JB and WB Allen Hydrologic Characteristics and Sustained Yield of Principal Ground-Water Units Potowamut-Wickford Area Rhoae Island USGS US Government Printing Office GS 67-324 1968
37 Roux PH and B Vincent Electrical Resistivity Evaluations At Solid Waste Disposal Facilities US Environmental Protection Agency SW-729 Cincinnati Ohio 1978
124
38 Salvato JA Wi lk ie WG and BE Mead Sanitary Landfill Leaching Prevention and Control Water Pollution Control Federation Journal v 43 no 10 Oct 1971 pp 2084-2100
39 Sawyer CN and PL McCarty Chemistry for Environmental Engineering McGraw Hill 1978
40 Stellar RL and P Roux Earth Resist ivi ty Surveys - A Method for Defining Ground-Water Contamination Ground Water v 13 no 2 1975 pp 145-150
41 Todd OK Ground Water Hydrology John Wi ley and Sons Inc New York 1959
42 Tolman AL Ballestero AP Beck WW and GH Emrich Guidance Mannual For Minimizing Pollution From Waste Disposal Sites US Environmental Protection Agency-500SW-677 Cincinnati Ohio 1978
43 Trescott PC Iterative Digital Model for Aauifer Evaluation US Geological Survey Open file report 1972
44 University of Rhode Island Academic Computer Center CalComp Contouring Manual
45 Warner DL Preliminary Field Studies Using Earth Resistivity Measurements for Delineating Zones of Contaminated Ground Water Groundwater v 7 1969 pp 9-16
46 White EF A Report to the Town of S Kingstown Utility Survey Engineering Corp 1967
47 Zohdy AAR A Computer Program for the Calculation of Schlumberger Sounding Curves Over Horizontally Layered Media Using the Method of Convolution US Geological Survey Denver
48 Zohdy AAR Eaton GP and DR Mabey Application of Surface Geophysics to Ground-Water Investigations Technidues of Water-Resources Investigations of the US Geological Survey Book 2 Chapter 01 Washington US Government Printing Office 2401-02543 1974
theory of liner installation and monitoring devices (13) Sanitary
Landfi11-Leaching Prevention and Control presents a review of
preventative methods such as means to minimize infiltration
interception of ground-water and other pollution control measures
(2 37) A study in Pennsylvania on actual measures implemented to
collect and treat a landfills leachate discharge presents a site
specific study (19) Leachate Quality Improvements After Top
Sealing1 shows that by minimizing infiltration at a landfill in
Connecticut the outflow leachate water quality can be improved
dramatically and contamination plume reduced significantly (6) The
most comprehensive reports on remedial approaches to upgrading waste
disposal sites and ground-water protection methods have been
compiled under USEPA contract (1542)
To assist in evaluating remedial measures the US Geological
Survey (USGS) computer model Iterative Digital Model for Aduifer
Evaluation was used It was originally developed as a model for
simulating two-dimensional aauifer problems (33) It had been
updated since its original development to accomodate different
options (43) This model has been applied to glacial outwash
regions in Rhode Island (717)
10
Description of Study Area
A map of tne landfill area (Fig Z) was obtained from tne town
of South Kingstown The excavation to the west of Rose Hill Roaa
the landfill area directly to the east and the presently operating
area to the east of the central stream comprise tne overall study
area This study will concentrate on the west landfill area whicn
has recently reached capacity and been closed to further dumping
This site received mixed refuse for the past 15 years The depth of
the excavation where the landfill presently exists was approximately
to bedrock in some places Tne exact depths of landfill material is
unknown
The landfill cover has been graded and sloped generally eastward
to convey surface runoff to the eastern side A sandy soil that was
excavated locally was used as tne cover material The northern
section has a vegetation cover and the recently filled southern
section has been seeded and mulched The six monitoring wells W
NW NE EC SE SC were placed by the town of South Kingstown to
provide water quality information
Referring to Fig 2 the west excavation stream drains the area
created by the excavation to the west of Rose Hill Road and flows
throughout the year The central stream drains a small watershed
area which lies to the northwest of the landfill and drys up during
part of the year These streams flow into the Saugatucket River
which flows throughout the year and is larger than the west and
central streams combined
11
The USGS Groundwater Map (18) was initially consulted to proviae
information on the ground-water flow patterns (Fig 5) and the
geology of tne area (Fig 6) The surficial geology borings and the
vertical geologic cross-section at the base of the study area
indicate shallow water table and bedrocic and a nearly constant
saturated thickness (18) Boring logs at the W well ana a point
approximately 150 feet south of it indicate glacial outwasn material
which is primarily sana with a trace of gravel over bedrock at a
depth of approximately 33 feet Borings at the east landfill area N
and S monitoring wells indicate the same aquifer material
(Appendix B)
The ground-water map developed by Hahn is taken as
representative of conditions existing prior to the excavation of the
I l andfill (18) This indicates water-table contour lines that run in i
a general northeasterly direction This means tnat flow was
originally in a southeasterly direction However contamination of
domestic supply wells on the west side of Rose Hill Road has
occurred (Fig 3) strongly suggesting that the original flow pattern
has been altered by the excavation to the west of Rose Hill Road and
the landfill to the east of it Domestic supply wells were formerly
located directly to the west of Rose Hill Road but were aoandoned
when they became contaminated from landfill leachate New wells
were located to the south and west away from the contaminant plume
of tne landfill In addition a well located at the northeastern
corner of the landfill was contaminated and a replacement located to
the east of Us former location on tne opposite side of the central
12
Legend scale 124000
mdash-40 mdashground-water contour elevation
Fig 5 Ground-Water Map
13
Legend feet
TILL
Fig 6 Geology Background Map
14
stream This second wel 1 also became contaminated Domestic supply
wells located near tne northwestern corner of tne landfill and
approximately 300 feet south of it nave remained uncontaminated
These well locations serve as an indication of tne extent of the
landfill contamination which is largely dependent on the groundwater
flow patterns To furtner investigate this problem and provide
substantial information on which to base the geohydrologic analysis
field studies of the area were conducted
15
Field Studies ana Procedures
A map of the lanafill and an aerial pnotograph of the area were
obtained A tracing of these maps superimposed upon another
delineates stream landfill and monitor well locations (Fig 2)
The field investigation concentrated on the west landfill area ana
its aajoining streams ana monitor wells The east landfill area and
the three monitor wells in that area are induced in the latter
phase of the study in oraer to expand the model area
A traverse which establishea tne monitor well elevations was run
using a Carl Zeiss level These were originally sitea in by the
town of South Kingstown using a local USGS reference datum number 40
(18) The wells of known elevations then served as benchmarks for
referencing adjacent stream elevations This in combination with
the depth to water table measurements at each well enables tne
water-table surface geometry of the area to oe visualized
Water-table measurements of the west landfills wells were recordea
over a ten month period to record fluctuations (Fig 7 Table 1)
The east landfill areas wells were monitored for a five month
period Using a given water-table condition a ground-water map was
developea of the area (Fig 4) This indicates an outflow from
the landfill primarily in a southeasterly direction and partially
in a southwesterly direction
Additional bedrock and water-table information was ootainea by a
seismic refraction survey at several locations along the landfill
perimeter A Bison Model lb70C Signal Enhancement Seismograpn was
used to maxe the surveys Lines were run (to a length of kOO feet)
16
17
w s p bdquo S bdquo s S S a laquolaquo _
s 2 8
V
r bdquo
3 s a
-R s
S
S 3
t
raquobullraquo
S
5
K
r
~
3
K
pound
7
S
bdquo3
C 5 S
shy raquo S s
1 3 s 3 2 5 ^ bull
5 m
s o
^ 3
raquo
--
R bull 5
s pound J O s
5 a 3 7 3 m
5 s a ^
iraquo a s rlaquo
M ^
^ c o 2 5 s 3 a S R
rd 3 y a O =J
^ bdquo
JJ s s 3 bull ~ I
~ s 5 3 a s a
(Ogt (U
2
-t =
r s s in
5 y
a s
5
3
s
5 a
^ a
3 a 51 a bullbull
sj 5 Ml
3 a bull
s raquo
a
0)
0
^ mdash
a j -
-3
C
g S
S
bull a
-
~ 3 o
2 s s 3 a bdquo s s $ Al s
(1) = $ s 3
S
c a a
3 e 5 s N s S a - 3 = s s a 5
a s s - 3 S shy
4
0
a s
bdquo tfH
bdquo
3 a
bdquo
s a
e bullfl s i s s a s a
3 nt
s s 3
g laquo s3 a
~ J s 2 a s o s S s 3 a a j laquo s o s
3 bull laquobull
2 a 7 3 a 3 a ^2
s mdash 5i o
bull bull
mdash
3 o
ss a
fc mdash
3 1-sect m ishy n
18
in both directions to provide a check and permit accurate estimates
of the depth to bedrockThe seismic results allow approximate
interpretations of the depth to the water table and bedrocK thus
permitting an estimation of the saturated thickness Ground
elevations at the location of the seismic surveys were determined
from a topographical map and field siting From this information
water table ana bedrock elevations estimates were made Bedrock
contours are listed in Fig 8 In addition a table which
summarizes the seismic refraction results for the unsaturated
saturated and bedrock layers velocities and depths at each survey
location is presented in Table 2
Scream gauging stations were established on the two streams
bordering the west landfill (Fig 9) Three stations were placed on
the central stream These provide information on the influent or
effluent condition of ground-water flow in the upper sections of the
stream and ground-water baseflow from an area adjacent to the
landfill into the stream (Table 3)
The stream gauging stations used were 90deg V-notch weirs The
weirs located in the SE and SW positions were placed in the
streamoea with a liner of plastic upstream to minimize underflow
The weirs located in the NW and E positions were cut to fit in
recesses of concrete culvert pipes Concrete plywooa interfaces
were coated with roofing cement to minimize bypass flow Upstream
water pressure and a snug fit hold the plywood sections in place
All weirs were implaceo according to AigtTM reouirements and flowrates
calculated using the standard 90deg V-notch formula (3)
19
N
seepage West observat ion Landfill hole
Area
Legend landfill limit excavat ion limit
copyWNWNEECSESC monitoring well locations
= = = unimproved road -- WNES-number
seismic refraction locations
-40shy approximate bedrock contpur elevation
feet
Fig8 Seismte Survey Location
20
c ^-^ c4j ^laquoc in -=r 3shyjj bull pn f- 4-gt bull in in OjJ bull bull a jo bull bull O JJ
co CM o on on CO CM CTNVO VO co CM o on on Q gt_x rH oj on a oj on a - rH oner
rmdash on sr i i
M z Z
gt gt gt
X-N CO laquomdashv CO CO bull igt gt bull
1 gt fc^gtgt bullbull ^ ^ ^
C 4-gt O t igt O J- 4J O H m o o o 3 bullH CO O rH in 3 bullH co vo o in 3 ~ 1 i-k -i ^trade fj rj ui ij o CO o n o rH =r co o n vo vo vo co o bullv O O O
O raquo On-3 rH O -bull- rH ON in _ IH in oj - rH bull rH VO OrH bull rH On ON pH d)u CO -UCO 4J OJ CO 4-gt gt
C mdashbull gt CM gt CM H-l O CO
v- ^^ N C 0
bull0 N CO
4-5 -0 _c^gt in in CO CO
C x~ c -^ t-oo in i 4J j_gt 41 4J bull 9 bull bull 4J bull
o j ON O O 3 (0 O4J O ON ON QJJ t~-^3- OJ 4-gt L
CO CM trade CO CM rH rH OJ co CM oj on Q ^ _ CO 3~Q-- n 45 Q mdash OJ OJ OJ C (0
1 11 3 nZ 2CO
gti gt gt CO CO CO ^-x m -s CO
rH rH ^ ro^^ bull gt bull ^ igt gt bullgt gtgt bull r O -Q 4Ji JJ O 5- JJ O pound- ^ O 4) oj o on (0 CO
3 bullH CJ O O in 3 bullH CO Cmdash VO on 3 pound-laquo H CO o n in inco co o n ma- r co g^ 5sect^ o
o rH on oj O bull- rH ONCO L O_ rH OJ VO M
rH bull rH =t rH bull - OJ T CO CO M CO 4-gt rH CO -U rH CO 4-) s
uits
CO 4-gt 4-5 T3 gt CM gt CM gt CM cc CO CO CO
3 3gt oa tlp^ CO O CM O gt 4J O 40 i 3 r+ k C pound JS
CO pound
^^ s -bullgt cmdash on poundZ VO CTI trx 4J 4J 4J
) bull bull bull Q Q Q Q4J 3shyc O-JJ CTgt OJ OJ Q-IJ inco on CO CO CO o co CM oj on co CM oj on co CM on
Q Q QON^ Q bullH Q^
rH rH 4J rH
O bullraquo L Z bull CO CO CO
i gtgt rH oj on gt tgtshyCM ^ cO^-s CO ~ CO
CO CO J X fc^_ bull^gt bullgtgt bull gt gtgt bull gt CO
j_ jJ O pound- Jj -P O Li deg =fObullH co on f- ^ 3bullH CO CO O in 3bullH CO
g^ -^2
poundsect HO
eis
mic
3 CO in in in in in in co o n co o n
o -^ r oj in O rHCO CO rH bullrH bull rH =T OrH bull rH OJ f-CO 4J bull- CO 4J rH O0) J-)
gt CM gt CM gt CM 4J
CO N_^ m^
bull OJ
t t poundshyCO CO CO CO rH J3 gt r-t oj on gt r-i oj on gt gt r n o j o n
lto co lto CO T bull ii-4 laquomdash bullmdashH
bullo CO L L 0)
CM CO cc
21
N
545-594
seepage observation
hole West Landfill
0NE I47-509
Area
Weir 45
i487-531
0 EC Al3-467
Legend bullmdash landfill limit -bull---excavation limit r-s stream
copy WNWNEECSESCSEN monitoring well locations
= = = unimproved road
Weir location and elevation
feet
Fig 9 Weir Locations and Wate r Level Ranges
22
JT NO
S shy S
O
bull ry m
oa
NO
(M raquo 1 03 or NO m
JT O O raquo
O NO 03 (j
PW tn in ^4 fraquo
m CN) f O O (M Oj
mdashraquo 3 M
s cshy -raquoraquo
o in in ^
rjO
laquobull NO ON
o bull-lt ^
H fy (NJ
tjgt
1 4 03 O
o
o
03 CM
in0
0
7 raquo
9gt
IM i iev NO
i in
i ru
i 0 rsi -or^
sO NO
CO O
03 raquo
1 O3
pound o ro CNJ
03
tn B OJ
o 03
m oi
NO
(M
r
(M
CO i M 03
m N ltn ~+ ltM -
QJrH
O M O ^ ^r-
oo m
8 a
m
^ NO
8 fNl
rshy03n
m - in
o laquoO
bull3 as m o 03 03 4
i O
i ^
shy
O
ltM bull^
ON f tn H 1 4 raquo4 i-4 H P-t
^^ lt-l
r-laquo
^ 1 1 1 1
pound raquoraquo O)t o gtz
bull bull ltbull
lt2
1 pound OJ
3 oi g bull
pound
1 pound laquolt bull
3 bull o a
pound
5 laquo15
f bull 3 Jl s
5bull 1 5
23
A field study to determine the infiltration capacity of a
section of tne landfill topcover was conaucted A modified version
of a double ring infiltrometer was used to study infiltration rates
(4) The cylinder diameters useo in this study were 8 inches and 18
inches A constant head of 6 in was maintained in the
infiltrometer and rates of infiltration were determined Tnese
results and an analysis of surface infiltration into the landfill
are included in tne analysis and discussion section
Specific conductance levels in the monitoring wells in the
streams bordering the landfill and at observation holes near the
landfill were measured (Fig 10) This is a good indication of the
mineralization of water (39) Specific conductances were measured
intermittently over the ten month period to develop a picture of the
extent and degree of contamination in the wells (Fig 11 Taole4j
and in the surface contamination monitoring locations (Fig 11
Table 5) A comparative standardization of the Beckman (short and
long probes) and YSI specific conductances is in Appendix C
A surface electrical sounding using the Schlumberger array was
conducted adjacent to Rose Hill Road at the R-l location (Fig 12)
in an attempt to delineate the vertical extent of the contamination
zone Well W was used as a centerpoint and a reference for
water-table depth pore water conductivity and depth to bedrock A
Schlumberger array electrical resistivity sounding was also
conducted in an uncontaminated area at tne R-2 location (Fig 12) to
provide a comparison background interpretation A seismic
refraction survey N-4 was conducted at the same location (Fig 8J to
24
N
excavat ion
Seepage West observat ion Landfill hole
Area
Stream 1 Seasonal observation 0 EC
hole
East Stream2
Legend sw Weir landfill limit j--1--^ excavation limit
copyWNWNEECSESC monitoring well locations
== unimproved road
feet
Fig 10 Surface Contamination Monitoring Locations
25
8000T
7000
O bull U) W6000
Legend
0 sc A NE O W
A SE O N W
a EC
1 O N D J F M M
Time months Flg11 Flucuatlon In Specific Conductance in Wells
26
Table 4 Specific Conductances in Wells (pmhoscm at 25degC)
West East Landfill Landfill
Date NW NE EG SE W SC N E S
81581 851 938 236 2356
102981 171 3268
11381 3268
111081 304 988 1100 258 3800
111481 426 2736 1216 186 4560
111781 304 3610 433 389 4560
121981 380 1406 129 103 380
1982 160 152
31582 274 760 1064 61 334 8000+ 182 53 84
52182 450 1500 1125 112 712 8000+ 175 255 150
52282 425 1320 1200 110 850 180 320 170
27
O
ct c r i c o o o o o c M o m o in CO CM unp^
3bull t- fmdash o^ co tmdash vo co in co cmdash co in a
bull bull1 1-1 trade4 rH rH^ CO 4)2
~ plusmn4J o O CM ^_
o n CO vO J oraquo 0C0M
cu rH rH rH rH rHin tmdash
3 iCM 4J
^j CO CO
E O0 ltU -H n o c E
See
pag
se
rva
t
rH O in 0 0 O O 0
O o x rH Cmdash
0 0n
cu rH mdash O tmdash X o o o o c o o o o r H r H i n o i n i n o O
bull L in oo co oo oo o cy cr o rH CM o cr ONc fcJ bullH on en m m rn c^n rH rH rH0 pound CO 3 CO
t CM0gt s o o o in rA n ^o oo in tmdash oo 0gt zr =r a- JT JT$_
T)C CO
~ E CO ^ _bdquo ltu CO g r H r n c n i n o o r H r H
vgtO ^D O ^^ ^O CO ^^ ^^ JJ 2 4) rH rHCO t
c CO
CO c 9) rH 0
CO -^ C c CO ltuo famp O trade t iH
0
bullo co n ^
oS
o ^^ bullH m
i co rn O CQ O1 CO CO 4) c2Q 3
CO
mdash^ bull cmdash CMin 1 gt rH vO vO O CTgt CO
s CTgt CO OO Ogt Craquo- tmdash cu O CO rH z 0
bull_bulllaquo
H bull L o in r in o oo in 3 rfy ff^ tir f^ CO C^~
4)bull
Z 3
^ ^ ^ ^ H r H r H r H r H rH r H C O r H C O a O C O a O a O C O C O r H i H r H CO OO - gt 0 0 ^ - gt ^ raquo - ^ ^ 1 - gt ~ gt - C O C O O O
U ^ raquo ^ - ~ raquo O ^ ^ O t ~ C O r H - r r ^ - ^ ^ JJ r H C M v O r H r H r H r H r H C M C M r H i n c r gt rH CO CM gt laquolaquo - - -^ bullmdash mdash bullraquoraquobullgt -v -v ^^
~ v O r H r H r H r H r H r H r H r H lt M C M C M CM O O r H r H r H r H r H r H r H r H r H r H r H r H rH
in rH cmdash
CO vo
CO vO
41 rH CO
CTgt rH raquo CM rH
cn CO
o 0 rn
CO cmdash
tmdash fshy
CM ao
iT rH
m
ogt ao
O o vO
CO t-
tmdash Cmdash
CM CO
rH CM
I
rH CT
O vO in
CTgt
in c^
CM ao
CM CM
in
-
bull
CO bO C bullH T3
cy ~
_
CJ E 3 ^ n c bullH
1-1
CO
^H
28
excavation
West Landfill
Area
Legend bullmdash landfill limit -bullbull--bullexcavation limit r~~s stream
copy WNWNEECSESCSEN monitoring well locations
= == unimproved road
electrical resistivity sounding
feet Fig12 Electrical Resistivity Sounding Location
L
29
allow estimates of depth to water table and bedrocic to be made
Soundings were carried out to 500 foot electrode spacings to insure
that hredrock was penetrated and to facilitate interpretation These
results and a discussion of the soundings interpretation are
included in the analysis and discussion section Schlumoerger
resistivity soundings were made using a Soiltest R-bO unit
30
Model Development
The USGS Iterative Digital Model for Aauifer Evaluation was
usea to develop steady state flow models of the study area (43) A
flow chart of the computer model and a brief explanation of the
subroutines usea is presented in Appendix D The stream locations
elevations and aauiferlandfil1 geometry and hydraulic properties
were input to the model to compute head values at each 200 foot
grid spacing node (Fig 13) The input data which is for the
existing excavation and landfill conditon is listed in Appendix E
The head values that are computed at each grid space are in turn
loaded into the CalComp plotting routine (44) where a grid spacing
is setup with the computed head values at each node The contouring
program linearly interpolates between these head values and
generates a contour map The computer simulated ground-water
contour map for the excavation and landfill is presented in Fig
14
The streams in the model generally serve as controlling boundary
conditions When using computer simulated geohydrologic models of
an area choosing the boundary conditions for the model that are the
same as prevailing conditions in the field is a critical step in
model development Extending the models boundaries to areas in the
field that have a minimum influx of ground-water across them
simplifies the proolem of calculating fluxes from outside the model
area The eastern boundary is bordered by glacial till which has a
low hydraulic conductivity estimated to be 67 ftday(2) This
contrasts to the high hydraulic conductivity of glacial outwash that
makes up the model area of approximately 107 ftday(3036j
31 N
o 9
bullO O
32
33
The Saugatucket River serves as the controlling boundary on the
east A small drainage area directly to the east of it provides a
minimal influx
Beyond the moaels northern boundary the glacial outwash valley
extends to the base of a till covered h i l l on the western half ana
on the eastern side extends along the Saugatucket stream Due to
the relatively large drainage area that lies upgradient from the
northern boundary a recharge flux eduivalent to 10 inyr over the
drainage area on the till hill and outwash area north of the model
area was input as underflow (Fig Ib) Part of this was input at
each northern boundary node Till has a lower infiltration capacity
than outwash so more of the precipitation w i l l be transmitted as
overland runoff resulting in a lower ground-water baseflow The 10
inyr of recharge that results in a ground-water inflow from the
combined till and outwash region represents an estimate that is
smaller than the 14 inyr recharge for glacial outwash areas in
Rhode Island (25)
The glacial outwash valley extends beyond the western boundary
No significant ground-water recharge flux was estimated at this
boundary A relatively low ground-water gradient exists to the west
of this which does not provide a significant flux across this
boundary Tne southern boundary is basically the outflow region for
the area and therefore would not reauire any ground-water flux into
the moael area across this boundary This boundary was set south of
the point that the streams in the model merge together Therefore
the streams which lie to the north of it are the controlling
34
scale 124000
Fig 15 Northern Drainage Area
35
boundary conditions The flux out of the downgradient outflow
region approximately eauals the influx from precipitation recharge
and boundary influxes
When tne stream configuration in the moael area are reviewed it
can be seen that they comprise a large portion of the boundary
area The screams can act as sources or sinks for water in the
model thus providing to and removing water from the aquifer The
leakance option was used in the model which provides for a confining
bed and aouifer area beneath the stream to be input
The leakance is defined as the hydraulic conductance of the
streambed divided by the streambed thickness which in this case is
taken as 1 foot The leakance value at each streambed node
restricts the flow between the aduifer and the stream The
streambed hydraulic conductivity is typically 01 the value of tne
hydraulic conductivity of the aduifer (717) The value 107
ftday was used for a streambed conductivity based on a value of
107 ftday for the aquifer The aduifer and stream hydraulic
inputoutput exchange at eacn node is calculated by initially
finding the difference between the initial field stream head
elevations and the computed head elevation values at the
corresponding nodes This head value is then multiplied by the
(Leakance value at each node) x (stream area of each node)
Therefore if the aduifer head was lower than the stream head the
stream would act as a source of water for the aquifer and vice
versa
36
Tne leaxance input at each stream node is the ratio of the
actual field streambed area in each node to the area of each node
which is 200 ft x 200 ft = 4 x 104 ft2 The west
excavations stream width is approximately 3 ft central 4 ft and
east 5 ft Therefore if tne west stream traverses the node
directly without meandering it presents a leakance of 3 ft x 200
ft4 x 104 ft = 015 Leakance and streamhead values were
input at each node to set up the stream flow parameters in the
models
A recharge value of 14 inyr over the entire area was input at
each node This represents a value of precipitation that is
transmuted into tne ground-water rather than being directly
evaporated evapotranspired through plants or overland flow
runoff The precipitation recharge flow from the stream into the
aauifer and boundary fluxes provide the model witn input flow
parameters
From analyzing the available information it was determined that
the study area lies within a glacial outwash area with a relatively
shallow bedrock The seismic survey around the landfill generally
indicates a depth to bedrock below the land surface of approximately
29-43 ft with corresponding saturated thicknesses of 19-33 ft as
seen in Table 2 This agrees with borings from tne USGS groundwater
map in the stuuy area (18j The seismic survey was run at a low
water table condition which was several feet below the high water
table level (Fig 9)
37
High water-table saturated thicknesses were used to develop
model parameters For the purpose of this model study the saturated
thickness was set at 30 ft except in the vicinity of well W where
there is a bedrock high (Fig 8) At this location a high water
table saturateo tnicxness of 8 ft was estimated In tne vicinity
the seismic survey was conducted the bedrock elevation at this
location is the highest and the saturated thickness the least Tnis
can be seen by an east-west cross section of tne landfill (Fig 16
The boring log for well W indicates a sand trace gravel outwash
material (Appendix B) Boring logs at the eastern landfill area N
and E indicate similar material On this basis the hydraulic
conductivity was estimated at 107 ftday (3036) Witn the
exception of the landfill and the bedrock hign areas the
transmissivity values were set at 107 ftday x 30 ft = 3210
fto day From the literature the hydraulic conductivity of the
landfill material was estimated at I ftday (19) The
transmissivity of the landfill material in tne nortnern section was
estimatea at 1 ftday x 30 ft = 30 ft^day or approximately two
orders of magnitude lower than the outwash In tne landfills
southern section the original excavation was not as deep as in the
northern parts The landfill material was estimated to makeup only
one half tne saturated depth the remainder being the original
glacial outwash material (Fig 17) Therefore the transmissivity
at the southern end was estimated at 15 ft x 107 ftday + lb ft x
1 ftday = 1620 ft^day These values were graded into the 30
ft^day values at the landfills northern halfway point These
38
were input as transmissivity values to the model at their respective
locations This model did not use the water taole option so
water-table fluctuations did not affect the transmissivities
39
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Model Calibration
A simulation was run using the initial estimates of stream
parameters aquifer and landfill hydraulic conductivities
transmissivities boundary and recharge conditions to approximate
water taole conditions in tne fiela Initially the existing
condition of the excavation area to tne west of Rose Hill Road and
the landfill to tne east were modeled in order to calibrate the
model to current field conditions as shown on Fig 4 The simulated
well values (Fig 14) fall within tne range of field values (Fig
9) The resulting contours also provide an approximate matcn This
can be seen by comparing Fig 4 with Fig 14 An additional check
was to match the flow loss and gain in the streams between tne weirs
in the central stream which w i l l be discussed later The
simulated flow value from the excavation drainage stream is the same
as that measured at the SW weir location Having calibrated the
model by approximately matching well water levels nead contours
and scream flow values different field conditions and possible
remedial measures can be simulated
When the model grid was laid out over the study area as viewed on
Fig 13 the stream configuration rarely traversed the grid nodes near
their central axis When the stream locations were input to the
computer the information was documented as crossing the central axis
of the grid nodes The result of this is a slight aberration when
the actual stream configuration is laid over the computer graphics
head contour output The streams dont always cross the groundshy
water contour at the logical location Rather than modifying the
actual stream configuration to adjust then to the computer output
their actual locations are presented
42
Simulations
i The primary focus of the computer modeling is to analyze flow
patterns under changing conaitions in the near vicinity of tne raquo
landfill The study areas overall flow patterns as they exist
today are first presented in order to realize the lateral east-west
head contour lines between the stream that directly borders the
landfill on the east side and the SaugatucKet stream (Fig 14)
This indicates a general southerly flow direction in that area As
different conditions are modeled these contours generally maintain
their east-west orientation In order to facilitate interpretation
of flow patterns in the near vicinity of the landfill flow patterns
to the west of the stream that borders the east side of the landfill
r are presented in the subseauent models
L- Natural Conditions
The results of modeling the original natural conditions are
shown in Fig 18 The excavation and stream to tne west of Rose
Hill Road and tne landfill did not exist in this simulation The
southwestern boundary consists of a drainage stream that was
delineated using an aerial photograph and stream elevations were set
using the topographical map The USGS ground-water map (18) was
used to estimate head values between the west excavation and north
streams These were input to the model as constant heads on the
models western boundary The resulting simulation generally matches
the southeasterly flow direction that is indicated on the
ground-water map (Fig 5)
A3
Legend
x-^- stream 400 = = = unimproved road
I f ee t
Fig 18 Natural Conditions
44
Excavation Without Landfill
The condition of the excavation to the west of Rose Hill Road
with its resultant drainage stream without the landfill was modeled
next (Fig 19) The extent of the excavation ana the location of
the new drainage stream were delineated using the aerial
photograph The west stream elevations were sited in the field and
used in the model The concept of a confining streamoed layer was
excluded in tne excavation drainage stream under the concept tnat no
significant organic layer had been built up within the 25 year
period that the excavation had been initiated Head values between
the west and north stream boundaries were interpolated and input as
constant head values on the northwestern boundary The west
excavation drainage stream creates a condition that alters the
natural ground-water flow patterns by creating a more southerly flow
condition the drainage stream providing a more immediate surface
outflow in that area
Landfill Without Excavation
The hypothetical case of a landfill without the excavation was
modeled next (Fig 20) The low hydraulic conductivity zone of the
landfill changes the natural flow conditions and creates noticeable
mounding This is evidenced by the decreased spacing of the head
contour lines and deviation from the lateral contour lines of the
natural conditions and higher head values (Fig 21)
45
Legend
excava t i on s t ream
400 unimproved road
f e e t
Fig19 Excavat ion without Landfill
46
Legend
landfill limit
bull - s t ream 400 copy WNWNEECSESC
monitoring well locations f ee t bullbull-bull=bull unimproved road
Fig 20 Landfill without Excavation
1
oin CM
bull
m u
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bullo 9
bullo 9
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47
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CM
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48
Landfill ana Excavation
The condition of tne existing landfill and the excavation with
the dam is the next condition modeled (Fig 22) The ground-water
elevations used to calibrate tne model correspond to an actual high
water table condition Between the NVJ and pound weir a streamflow loss
of approximately 102 gpm occurs aoout 60 percent of this flow is
lost at the dam site which maintains a head of b-6 feet over an area
of approximately 1800 feet^ This approximates a field value of
1144 gpm influent to the aduifer between the NW and E weir on ]2
December 1981 (Table 3) From the E weir to the SE weir a net
increase in flow occurred of 74 gpm which corresponds to field
increase of b62 gpm
The surface runoff from tne landfill flows primarily toward tne
eastern side of the landfill Increases in water-table elevations
on the eastern side after heavy rains such as the 11 November 1981
storm indicates that this runoff increases outflow gradients to the
stream and therefore increases streamflow Surface runoff input is
not modeled which explains in part why field stream inflow values
are slightly higher than model predictions especially for periods
after a storm has occurred The flow from the SW weir located at
the southern end of the excavation represents drainage outflows from
that area The net flow calculated in the model was 140 gpm
which approximates field conditions of 1642 gpm on
December 9 1981
49
d f l f reg N E
shy
Legend
landfill limit -bullgt-bullgt- excavation ^-N_X- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road
-40mdash approximate groundwater contour
400
feet
Fig 22 Landfill and Excavation with Dam
50
The modeled flow patterns suggest how the various contamination
zones around the landfill have developed to their present state
They indicate a flow to both the southeast and southwest on their
respective sides of the groundwater divide Evidence of a
southwesterly contaminant flow is presented when the continued high
specific conductance contaminant level in tne observation seepage
hole is realized (Table 5 ) In addition the specific conductance
increase in the west excavation stream is evidence of an influent
contamination flow
Contamination flow to the eastern and southeastern side of the
landfill is obvious High specific conductance levels in the wells
on the eastern side (Table 4 ) a specific conductance increase
between the E and SE weirs (Table 5 ) and contamination in the NE
domestic supply well (Fig 3) present conclusive evidence of
contamination to the eastern side of the landfill
An anamalous condition that exists is a domestic supply well
located approximately 300 feet due south of the landfill remains
uncontaminated (Fig 3) Flow patterns indicate that contamination
would be transported from the landfill south to this area
(Fig 14) One explanation is that a pocket of clay at the southern
end of the landfill area was discovered in the original excavation
for the landfill (lt6) This evidently prevents leachate from
reaching this wells radius of influence
51
Summer Conaitlon
As described earlier during dry months of the year the stream
that normally borders the northern and eastern side of the lanafill
may dry up as far as a point southeast of the E well Tnis
condition existed from the 15 August 1981 to the 27 October 1981
period when streamflow commenced in the northern part of the stream
yet did not overflow the north dam until 17 November 1981 This
created the present day continuous flow condition throughout the
stream These summer conditions were modeled by removing the stream
above the aforementioned location while other conditions remained
the same (Fig 23) Summer condition well water levels listed in the
model generally match field low water table conditions (Fig 9)
Because there is no stream upgradient from the landfill to provide a
stream head and infiltration through the streambed groundwater
runoff from the area north of the lanafill is the controlling flow
input In these moaels an average recharge of 14 inyr was used
which represents a yearly average The summer recnarge conditions
are prooably lower given the effects of decreased rainfall and
increased evapotranspiration during the summer months A domestic
supply well whicn exists northeast of the landfill (Fig 3) nas a
greater potential to be contaminated from the lanafill at tnis time
than when the stream is flowing Flow patterns from the landfill
are such that during an upper stream no-flow condition groundwater
flow patterns are more in an easterly direction than in a
southeasterly direction The stream would act as a source of
infiltrated water upgradient from tne landfill and provide a
52
I ^N gt i I i j i -r- -bull- bullr -T- t- -r- i- TJ JV
bullbullT laquo ^ O - laquo bdquo xi cshy
H r^~ I -~- --^ X- = mdash x^ N
^--^ A bull O^NW -v - gt-bull Ni i I _____mdash - bull laquo l - mdashmdash 1 deg I ^ltv I C
I reg NE A
Js bull vbull A ~ - v T gt- ^ ix - N
-5Z- | N TfS lV I -bull bull iA i gt gt I ^ bullr-Ky L bull 1 _- copy]wgt-- - bull- mdash - - shy
= r Y ~mdash ltmdashA A
^^-lt A _ - - - - bull Hmdash - reg EC x ^-mdash mdash I ---mdash_mdash -t-V-^N - y
I- -bull - r x i X
V ^ 7 I -v (^~~^^r ^^^
sc Emdash-bull vV JI - - - ~ r )N y- -
X - bull r bulllt
^bull^ y y Jlaquo^ - -lt shy
T s^ lt^ ^ +^-b (
X
Legend
landfill limit j-j-bullraquobull excavat ion gt^ -x- s t ream
reg WNWNEECSESC monitoring well locat ions
= == unimproved road fee t
Fig 23 Summer Condition
400
53
constant head across tne northern section of the landfill This
would tend to orient the flow in a more southerly aowngradient
direction In addition the stream which flows adjacent to the
northeastern well could provide a source of infiltrated clean water
to it which would minimize the possible contamination from landfill
leachate
Without Dam
During tne spring scream flow condition the dam failure which
occurred between the 15 March 1982 ana 9 April 1982 monitoring
periods decreased flow to the aauifer and landfill This eliminated
the 5-6 foot head difference over a 19000 ft^ area which had
created a larger area and elevation head for infiltration to occur
The condition without the dam was modeled by reducing the area
encompassed by the dam to a 4 foot wide stream channel thus
reducing the leakance value at that node (Fig 24) The flow change
from the stream to the aduifer between the NW weir and E weir
reduced the model flow loss to 50 gpm Tnis corresponds to the 9
April 1982 monitoring period which indicates a 30 gpm loss
As compared to the previous flow loss in the upper stream
sections to the aauifer the 21 April 1982 and 22 May 1982
measurements between the NW and E weirs indicate a flow gain The
streamflow conditions have changed from an influent
stream-to-aauifer condition to an effluent aduifer-to-stream
condition that increases flow downstream
54
Legend
landfill limit j--i--i- excava t ion x-gtmdash^- stream 400
copy WNWNEECSESC monitoring well locations
= == unimproved road f e e t
Fig 24 Landfill and Excavation without Dam
55
Analysis and Discussion
In order to fully understand flow patterns and Quantify leachate
outflows at the landfill it is necessary to arrive at an estimate
of flow inputs from precipitation ana upgradient sources In the
following analysis it will be demonstrated that the rainfall input
to the landfill is the factor which controls leachate generation A
calculation using the H inyr recharge over the area of the
landfill was made to estimate the leachate outflow due to rainfall
infiltration An estimated 134 gpm is generated from the entire
landfill area Simulation of the existing conditions (Fig 24)
indicates a groundwater divide in the landfill is located
approximately at the western third Therefore approximately 23 of
the generated leachate flows to the eastern side of the landfill or
9 gpm The effect of the flow input from the upgradient stream is
evident when tne summer condition witnout the stream is viewed
(Fig 23) Without the stream to infiltrate the landfill and the
recharge and northern boundary condition as the flow inputs the
head at the northern end of the landfill drops about 5 feet from its
previous value A flow pattern from the north central part of the
landfill to the eastern side indicates a 12 feet head difference
with recharge - but with the upgradient stream a 16 foot head
difference occurs Considering the transmissivity change the
stream would increase the leacnate outflow from the landfill
approximately 43 under a low water table stream influent condition
to the aauifer This would increase leachate outflow to the east
side to approximately 129 gpm This value approximates the
56
outflow at the SE weir location during the summer monitoring period
when the upper stream was not flowing (Table 3) The outflow from
the western third of the landfill whicn lies to the west of the
ground-water divide would be approximately 63 gpm
Realizing the importance of infiltration to tne landfill as a
major influence on the generation of leachate an analysis of this
w i ll be discussed An estimate of infiltration was made using the
precipitation recora for October ana November (Appendix A) During
this time period a minimum of direct evaporation ana
evapotranspiration occured and the grouna is not yet frozen The
top cover over the lanafill is generally 05 ft to 2 ft of local
sandy soil and subsoil availability determined what was used The
top of the landfill is at an elevation of 92 ft as compared to the
ground surface at well W which is at an elevation of 76 ft
(Fig 25) This compares to the well W water level which is at an
elevation of approximately 52 ft This creates a long path for
infiltration through the unsaturated zone The topcover generally
slopes eastwara at a grade of 2-5 The west side maintains a
relatively steep slope of 10-15 ft drop within 50 ft ana the north
and eastern slopes have a more gentle slope of approximately 10 ft
within 100 ft distance An unlined surface arainage swale channels
surface runoff from the northern section of the landfill past the
NE well to the eastern side ana low area in the vicinity of the E
well This has a drainage swale to an area near the stream but
doesnt directly connect to tne stream A poorly graaed drainage
swale exists on the landfills left side The landfill material has
57
excavation
seepage observation ^
hole
Legend bullmdash landfill limit -^--excavation limit r^s- stream
copy WNWNEECSeSCSEN monitoring well locations
--- unimproved road O location of amp Inf i l t rometers O
feet
Fig 25 Infi ltrometer Locat ion and Drainage Feature
58
been placed in 10-12 ft cells and covered with 1 ft of soil at the
end of each day The material has settled differentially creating
areas for depression storage
An estimate of the percentage of precipitation that infiltrates
the landfill was made from precipitation records recorded well
elevations and an estimated specific yield for the landfill
material The volume of water that infiltrated should eaual tne
specific yield multiplied by the well water level rise Several
recharge periods were studied using this relationship Once the
percentage of precipitation that has infiltrated is determined the
percentage that is translated into runoff is simply the remaining
percentage if evaporation is neglected
From the literature for a slightly inclined slope of 2-5
typical runoff coefficients range from 10-20 in either sandy or
heavy soil (16) The landfill cover is generally sloping to the
east which creates a long path (approximately 400 ft) before the
runoff reaches the steeper slope on the eastern side of the landfill
of 15-20 The long drainage distance creates a greater time for
rainfall to infiltrate Another consideration is the actual
capacity of the soil to conauct water into the soil which was tested
in the field using double ring infiltrometers An average initial
percolation of 8 mmhr the first hour and a subseauent rate of b
mmhr occurred (Fig 26) The 8 mmhr rate compares well with
other sandy soil infiltration rates (14) Therefore if the
intensity of the rainfall exceeded a 5 mmhr rate for several hours
59
CO + 09 o
E o
CO
o Z pound C
O
C9
o DC
CO
CD CM
ogt CO N- to -4 CO CM
jq tuu i U O | raquo B J J | | J U |
60
on a poorly drained surface the additional rainfall would be
translated into runoff because the soils infiltration capacity had
been exceeded
The initial 8 mmhr infiltration rate was due to the pore spaces
in the sandy soil being filled and the subsequent 5 mmhr rate was
percolation into the low permeability landfill material The tests
were conducted in November assuming a minimal evapotranspiration
and the field capacity of the sandy soil had been maintainea
The W well was used as representative of the water elevation
changes in the landfill because it is directly adjacent to the
landfill 900 ft distant from the upgradient stream This minimizes
the effect of infiltration from the stream and maintains a high
contaminant level During periods of high runoff conditions excess
surface water ponded in a poorly graded drainage swale on the west
side and directly adjacent to the landfill This influenced the W
well at a time the contamination level dropped (Fig 11) Before
this occurence in mid-December the rise of the W well closely
matches that of the SC well and a background well SK6 which is
located outside the study area (Fig 7) Therefore it was analyzed
as a valia indication of the water level rise during the mid-October
to mid-December period The monitoring of the SC well was
intermittent due to inaccessaoility because of 10 ft extensions
being placed on the well as the refuse was being filled in arouna it
61
A high rainfall period from 14 November 1981 to 1 December 1981
was chosen for the initial study period The effects of
evapotranspiration were neglected due to the cool temperatures
experienced at this time Therefore it was assumed that the field
capacity haa been reachea and tnat any additional input to tne
unsaturated zone would result in direct percolation to tne saturated
zone During the time period 14 November 1981 to 22 November 1981
029 ft of rainfall fell and the well W rose from 488 ft to 493
ft - a 05 ft increase During the next 8 day period there was no
precipitation yet the W well continued to rise to 4972 - a 042 ft
increase The slow percolation of water through the landfill
material would account for the latent rise in the well water level
From previous reports a specific yield for refuse was estimated to
be 028 (1920) This value is dependent on the original compaction
of tne material age and resulting consolidation
During the 14 November 1981 to 1 December 1981 period 029 ft
of rain fell and the well increased 092 ft The following
relationship is used to evaluate the infiltration value and runoff
I = (Sy) h
Sy = specific yield
h = well rise
I = volume infiltrated
I = (028) (092 ft) = 0261 ft
62
The difference between the precipitation and the infiltration is
the runoff (assuming no evapotranspiration) Therefore 029 - 026 =
003 and furthermore 003029 - 13 runoff This corresponds in
the literature to a typical runoff coefficient for an inclined
surface of 2-5
Analyzing a longer precipitation period from 18 October 1981 to
1 December 1981 a net precipitation of 043 ft (accounts for
evaporation) occurred less 10 for runoff or 039 ft infiltrated
This results in a 139 ft elevation increase The well water level
actually increased 132 ft shy only a 5 deviation from the
calculated
From tnis investigation it is seen that a large proportion of
the precipitation has the potential to be transmitted into the
landfills saturated zone Exceptions are wnen heavy precipitation
periods exceed the soil percolation capacity frozen ground prevents
infiltration and direct evaporation and evapotranspiration recycles
the ponded surface water and infiltrated soil moisture back to the
atmosphere In retrospect water temperatures within the monitoring
wells could have been measured to indicate thermal effects from the
landfill on ground-water temperature Ground-water temperatures
were assumed to be 50deg F (9)
63
Specific conductance measurements serve as an indication of
contamination levels These measurements are used to trace leachate
movement which represents ground-water flow patterns Factors which
must be considered when monitoring pollutants are the attenuation of
the leachate contaminants which occurs both in the zone of aeration
and the saturated zone The former is a more complete process
Dilution dispersion and cation exchange are the primary factors
involved in decreasing leachate concentration in the saturated
zone The glacial outwash materials of southern Rhode Island do not
have a cation exchange capacity or a high buffering capacity so
attenuation is simply by dilution and dispersion (22)
The NW well consistently exhibits relatively low specific
conductance levels even though it is in landfill material It is
situated in a drainage swale and ground water elevations range from
543 to 5944 This is several feet below the upgradient stream
elevation of 64 feet which is less than 400 feet away The bottom
of the wellpoint is at an elevation of 5312 feet well into the
landfill material Infiltration from the stream to the landfill has
occurred at this location
The W well is situated on a bedrock high adjacent to the
landfill approximately 900 feet from the upgradient stream and its
water level is higher in elevation than the excavated pit (West
Observation Hole) which is 300 feet directly west The W well
maintains a contaminated level A poorly graded drainage swale to
the west of the landfill provides areas for extensive ponding and
infiltration to occur which explains the drop in conductance after
a high runoff period
64
The SC well is located in landfill material and has a
conductance of over 8000 umhos This indicates that leachate is
undiluted The oottom of the wellpoint is at an elevation of 389
feet which is situated in the landfill material
High specific conductance measurements in the west observation
hole and well W and their relative elevations indicate a
west-southwesterly flow direction from the landfill Infiltration
recharge and leakance from the stream into the landfill provides the
necessary elevation to cause outflow in this direction
Contamination from the landfill to the surrounding streams is
evident (Table 4) During the period 15 August 1981 to 27 Octooer
1981 there was no flow in the stream that Borders the northern and
eastern side of the landfill until a point just south of the E well
was reached High specific conductance levels in the EC and NE
wells were recorded (1000 jjmnos) At a point directly east of well
EC a pool of water existed that was relatively uncontaminated which
is designated as the East Stream] location (Fig 10) At a point
just south of that (East Stream^ polluted water in the streambed
was flowing at a low rate This was measured at the SE weir
location and which had a high conductance also Flowrates varied
between 6 and 23 gpm and specific conductances were over 350
pmhos This low water table condition flowrate is the baseflow from
the eastern side of the landfill and indicates a southeasterly flow
direction from it
Streamflow commenced in tne northern part of the stream 21
October 1931 and the north dam oegan to f i l l Stream specific
65
conductances were low indicating a clean water source Tnis
continued until 17 November 1981 when the dam overflowed ana flow
throughout the east stream began A weir was placed at the Rose
Hill Road NW location and was compared to flowrates at the SE
location Flowrates decreased and specific conductances increased
between these two locations
To further investigate the condition of a lower flowrate
downstream than upstream an intermediate weir was placed at the E
weir location (Fig 9) This snowed tnat the stream from the M
weir to the E weir was losing water to the aauifer (influent
condition) and gaining water at the SE weir (effluent condition)
The condition of a net loss of water between the NW and SE weirs
remained until 19 December 1981 when a snowmelt rain condition
caused increased surface runoff and a net increase in flow at the SE
location Upon analyzing the March and April 1982 streamflow
conditions the expected case of a net ground-water pickup from the
E to SE weir continued The explanation for tne initial net loss of
ground-water is the fact that the leakance from the upstream section
was being discharged into aauifer storage to raise the ground-water
table to an eduilibrium level Upon reaching a high recharge
equilibrium steady state condition any additional input will
eventually be transmitted as baseflow out of the landfill and a
downstream net pickup will occur A hign water table condition
prevailed during the January through May period maintaining this
condition In April the north dam broke through reducing the head
in that area by 4-6 feet The 9 April 1982 monitoring revealed that
66
an influent condition remained between the NW and E weirs but at a
reduced rate The 21 April lower stream flow condition shows a
small pickup of water between the NW and E weirs indicating the nigh
water table and low stream flow conaitions combined with the absence
of the dam had changed the conditions to an effluent condition
This was evident in the May monitoring period
Evidence of contamination on both the western and eastern sides
of the landfill supports the existence of a ground-water divide in
the landfill The west stream which drains the excavated area to
the west of Rose Hill Road shows contamination pickup between its
northern section and the SW weir The W well and ooservation hole
indicate high contamination levels which reinforces the concept of a
contaminant outflow to tne west excavation stream
As shown previously flow towara the eastern side of the
landfill is evident from the nign specific conductances and specific
conductances increases in the stream This is especially evident
during low flow conditions when the stream starts at a point to the
east of the landfill and flows with high specific conductance levels
From the literature a relationship between specific conductance
and dissolved solids exists the dissolved solids (mg1) are
approximately equal to the specific conductance times a factor
ranging between 55 and 09 (39) in this case it is taken as
065 (41) The dissolved solids increase coupled with the stream
flow increases provides a basis of calculating the dissolved solids
outflow to tne stream This calculation method was used in a
previous study (26)
67
The relationship
=Cinout Coutflow Qoutflow - Cupstream Qupstream Qinput
where the numerator is the streamflow pickup and the C- and
Q-jnput is the concentration and flow input from the ground-water
This can be used to estimate dilution level outflows from the
landfill Initially this is used for the ambient ground-water
pickup between the E weir and the SE weir This entire flow doesnt
come from tne lanafill but much of it is conaucted in the high
transmissivity area between the lanafill and stream from upstream
leaxage ana surficial recharge Tnis is evident when this section
of the flow pattern is analyzed on Fig 22 Therefore the landfill
outflow is mixed with tne ambient groundwater flow which dilutes the
landfill leachate before it enters the stream To illustrate-this
concept a calculation using the 9 December 1981 monitoring is used
At this time a flow of 672 gpm occurred at the SE weir with a
specific conductance increase of 7 ymhos between the E and SE
weirs The dissolved solids increase would be approximately 795
Today in tne stream
Where
Co = 90 jumho at SE weir
Qo = 672 gpm at SE weir
Cus = 83 jumho at E weir
Qus = 606 gpm at E weir
Qinput = 66 gpm gain
Cinput = 154 jumho
68
The 154 jumho value represents the contaminant level in the
ground-water adjacent to the landfill
This relationship is applied to approximate the concentration
level dilution in the ambient ground-water between the landfill and
stream The aforementioned relationsnip is in turn applied to the
landfill outflow into the ambient ground-water flow adjacent to the
landfill The ground-water receives landfill leachate dilutes it
and then transmits it to the stream The previously calculated
value of 129 gpm was used as the outflow from the landfill
Co 154 jumho flows into stream
Qo = 67 gpm flow into stream
Cus = 83 jumho background level
Qus = 67 gpm - 129 gpm = 541 gpm
Qinput = 129 gpm from landfill
Cinput = 451 jumhos
Approximately tne same contaminant levels from the landfill (tbl
umho) are arrived at as existed in the summer streamflow conditions
when the upgradient ground-water flow adjacent to the landfill was
at a minimum
In addition to using specific conductance to define
contamination zones electrical resistivity can be used to indicate
contaminated areas The measured earth resistivity is inversely
proportional to the conductivity of ground-water Water containing
contaminants with high ionic concentrations are more electrically
conductive and will have lower resistivity values than surrounding
natural ground water Therefore resistivity methods can be used to
69
delineate plumes of contaminated ground-water that have hign
specific conductances This has been demonstrated by several
investigations (11122328374045)
In this study a Schlumberger vertical electrical sounding R-l
was made in an area of known contamination at the W well (Fig 12)
Given the geologic constraints provided by the well boring log a 4
layer computer model was used to match field survey values A
Schlumberger sounding R-2 in an uncontaminated area north of the
landfill in the same geologic setting was used to provide a
comparison background sounding (Fig 12) A seismic survey N-4 was
made to obtain water table depth and depth to bedrock as input
parameters to a four layer resistivity model (Fig 8) Tne results
of the electrical soundings have been tabulated in Table 6 and
plotted in Fig 27 and 28 respectively
The ascending portion of the field Schlumberger curves were
initially matched using a two-layer ascending type master curve to
provide an approximate depth and apparent resistivity of the
overburdened topsoil layer (8) Tne second unsaturated layers
apparent resistivity was determined by using the graphical
interpretation of total transverse resistance The total transverse
resistance is approximately eoual to the peak value of the curve
times the corresponding Ab2 distance it occurred at This in turn
is eaual to the sum of the first two layers apparent resistivity
times their corresponding layer depths
70
bullH
OJ bull bullH 4J CO CM
c ce G bullrH
j-gt ca c c a 3 ltu O L
co CO 0
bullo Q bull laquos c n 3 -U OrH f~ 3 bO ltn y CO O cc CO ^mdashN
QQ bull
bO bOJJ C C Ci_i
O l T i O O O O O O O O O O O O O O O O bullH bullH mdash^ bullo 0 C c3 f| 3 O raquo O CO CQ
CO
rH
CO O
L 4J
^ltU
i- 1 ^n ^b O 4-) bull2 CM bullH C OJ 1 -U bullH CO C L O a ^-^ 0) a
rH c a L CD ltu (1) 3 tlt bO cO I
3 a 0) a Q 4J laquoa e CO 3 (H bO c C O bullH
CO TJ C 3 bull
bull O bO -i-3
0 CO C O3- O G O O O O O O O O O O O O O O O O O O ft rt1 -raquo - t l S^ ft tfigt f I mdash^ K_ l_ raquo mdash I gt fgt I l 1
(1) 0 rH CO CJ JD o^^ CO CO CQH lts
71
Legend
A actual field measurement
-e- interpretat ion
10000 bull
6000 bull 5000
4000-
3000shy
pound2000| ltD
_ r 1000
09
5 600 pound 500 - 400
I 300 a a lt 200
100 10
Fig 27
20 30 4050 100
Distance AB2
Schlumberger Sounding
200
feet
R-1
400 600
72
loooot
6000 5000 4000
3000+
laquo2000 e
r 1000
raquo 600 pound 600 ~ 400
$ 300 a a lt 200
100
Legend
A actual field measurement
-Qmdashinterpretation
10 20 30 40 50 100 200 400 600 Distance AB2 feet
Fig 28 Schlumberger Sounding R-2
73
Formula T = f
Background Sounding (9000)(15) = (3110j (1 7) + gt2(8)
= 16214 n- ft
W Wel l Sounding (b200)(60) = (500) (2) + pound2(28)
= 13250 SL- ft
To determine a resistivityp3 value for the third layer a
graphical interpretation for the longitudinal conductance S was
used(48) This is eaual to the sum of each individual layers depth
divided by their apparent resistivity
Formula S = -r1 +~r-raquobull-ra
Background Sounding 0017 = yyg + ~^
= IbOU - ft
W Well Sounding 0285 raquo -ggg 7^3 J~
= 179 v-ft
These values were input to a program which calculates a
schlumberger sounding curve (47) The theoretical sounding curves
approximately match the field curve as viewed on fig 27 and fig
28 To provide a check on the apparent resistivity of the saturated
layer at the W well the following relationship was applied 1OOOO
= spec-jfic conductance (umhos)
74
At the W well the specific conductance was measured to be 3 00
jmhos at approximately 10degC
Assuming a formation factor of 45 for the glacial outwash (23)
material Archies law is applied to estimate an apparent resistivity
of the third layer (7)
fgt FF x p
A= 45 x 103-n-ft
A= 4G3 JL-ft
This is a reasonable approximation to tne 3i= 179^-ft calculated
analytically from the sounding curve interpretation
75
Remedial Measures
With the analysis of f low patterns and contamination zones
recommendations to minimize the environmental impact of the leachate
can be reviewed The basic technique is to minimize all sources of
water reaching the refuse so that leacnate production is minimized
The oiversion of precipitation by a relatively impermeable cover and
proper channeling of runoff would minimize percolation into landfill
material Caps and seals can be constructed of clays fly ash
soils soil-cement lime stabilized soil memorane liners
bituminous concrete and asphalttar materials (15) Proper
contouring and grading will help minimize infiltration If a soil
cover is used a vegetative cover can be planted which will utilize
some of the infiltrating flow through evapotranspiration losses
during the growing season By minimizing the length of slopes and
providing proper drainage channels tne surface runoff can be
conveyed to a downgradient area outside the recharge zone
Therefore this surface water will not increase leachate production
from the landfill Also by increasing the slope of the cover over
the landfill itself a higher percentage of runoff and lower
infiltration will occur
To minimize upgradient ground-water influx to the landfill an
impermeable subsurface barrier or intercepting trench could be
used Barriers can be made of bentonite slurry-trench cutoff walls
grout curtains or sheet piling cutoff wal ls extending to the bedrocic
or an impervious layer to effectively prevent water passage or
create a head loss that wil l lower the water table In addition an
76
intercepting trench which has a perforated drain at tne lowest part
of the water seepage zone could be used to intercept and divert the
entire flow
These possibilities have been evaluated with the help of the
model to determine workable solutions for this landfill The
primary concern is to eliminate leachate flows to domestic wells
Initially a simulation was run that eliminated recharge over tne
landfill area (Fig 29) This had a considerable effect on the
ground-water flow patterns of the landfill area The mounding that
had previously occurred under normal recharge conditions was
eliminated and a general drop in the water taole within the landfill
of 2-3 ft occurred The effect of eliminating recnarge over the
landfill when the upper stream is running would cause greater
infiltration from the stream as evidenced by only a 2 ft head loss
in the landfills flow conditions This is evident when comparing
Fig 29 with Fig 24 Tnis indicates that this measure would only
marginally reduce the resultant leachate flow from the landfill
material that lies below the water table In another situation
where there is not such a strong potential for upgradient flow this
measure has proven quite effective (6) In this case the landfill
cover consisted of four layers an intermediate sand and gravel
cover immediately above tne regraded waste materials a 4 inch sana
bed designed to protect the overlying membrane a ilO mil flexible
PVC membrane and an 18 inch final cover of sand and gravel
77
Legend
landfill limit -raquo- -^ -raquobull excava t ion x-^x- s t ream
400 copy WNWNEECSESC monitoring well locations
= -= unimproved road fee t
Fig 29 No Recharge over Landfill
78
Controls such as 10-30 mil polyvinyl chloride covers favor the
development of an anaerobic environment which increases waste
decomposition time and would necessitate installation of gas vents
at several locations on the landfill cover Tne integrity of tne
synthetic cap may be further threatened by subsidence which create
differential stresses on liners Settlement would create areas for
ponding and depression storage and eventually necessitate regrading
the landfill surface The landfills south-central area has oeen
filled within the last year and will prooably need to be regraded
due to settlement within the next few years
Another possibility for a liner would be a soil-bentonite
cover A layered cover consisting of natural materials with low
permeabilities such as bentonite clay followed by a layer of highly
permeable material such as sand and finally a layer of topsoil can
be used Due to potential drying out and cracking of the clay liner
a synthetic liner is the preferred method
The most immediate technique is to grade contour and vegetate
the landfill cover which has been done at this site Althougn an
impermeable cover would probaoly reduce the amount of leachate
produced it would not eliminate the upgradient flow and provide
guaranteed protection of wells in the vicinity of the landfills
northwestern section
A slurry trench along the northwestern perimeter of the landfill
would effectively cutoff upgradient infiltration and divert recharge
infiltration in a southeasterly direction thus removing possible
leachate outflows from the radius of influence of the neighooring
79
wells This has been simulated using the computer moael ana flow
patterns as shown in Fig 30 Contour lines are distorted in the
vicinity of the slurry trench due to the 200 ft nodal spacing
Transmissivity values of 1 ftday were input at the slurry
locations to simulate an impermeable barrier Tne surface recharge
at those nodes does not infiltrate the relatively impermeable grid
nodes at the slurry locations and flows to the edge of the noae
thus creating a dramatic head loss within a short spacing To
effectively simulate this a variable grid spacing should be used
with reduced node grid spacing at trench locations to eliminate
distortion The computer simulation shows that the slurry trench
could direct flow in the landfill area in a southeasterly direction
and away from endangered wells In addition it would reduce
upgradient infiltration from the stream into the landfill This
measure would prevent leachate from spreading beyond this carrier to
possibly contaminate neighboring wells
The combination of both the slurry wall and impermeable cover
would be ideal measures to minimize generation of leachate and to
stop its spread to neighboring wells The slurry wall without
recharge over it or the landfill is simulated in Fig 31 This
indicates a lower water table tnan eliminating the recharge to the
landfill The slurry wall has blocked upgradient ground-water flow
at its location to the landfill
80
Legend
landfill limit -laquo- j -laquobull excava t ion ^^- stream
copy WNWNEECSESC monitoring well locations
= = = unimproved road ssi slurry wall
f e e t
Fig 30 Slurry Wall
81
Legend
landfill limit j- j- J- excavat ion x-v^gt- stream
reg WNWNEECSESC monitoring well locations
= = = unimproved road s==s slurry wall
400
feet
Fig 31 Slurry Wall without Recharge Over It or Landfill
82
An intercepting drainage trench is considered next If a trench
was excavated to a 30 ft depth in the outwash material extensive
shoring would be required In addition difficulties would arise
when the trench was excavated below the waterline Tne trench would
be sloped to provide drainage and backfilled with a highly pervious
material to intercept and divert leacnate locally a conouit which
is perforated on the top to allow infiltration and unperforated on
its lower perimeter to permit continuous drainage to the collection
treatment center would be installed on the bottom of the graded
trench The difficulties involved in excavating below the water
table ano shoring the sidewalls to permit implacement of a drainage
conduit at a 30 foot depth make this option increasingly infeasible
83
Conclusions and Recommendations
The location of the South Kingstown landfill in permeable sand
and gravel glacial outwash material (107 ftday) combined with the
high hydraulic gradient across the landfill area (20 ft1600 ft)
creates a high potential for ground-water contamination to occur
This is intensified because refuse nas been placed below the water
table The low hydraulic conductivity of the compacted refuse (1
ftday) and the excavated area to the west of Rose Hill Road have
both contributed to modifying the original southeasterly flow
pattern These modifications have created a ground-water divide in
the landfill at approximately the western third section Tnis
results in approximately 13 of the leachate flow from the landfill
or 63 gpm flowing in a southwesterly direction and 23 or 129
gpm flows in a southeasterly direction Infiltration from
precipitation recnarge over the landfill (up to 9Upound) and from tne
upgradient stream during low water-table periods provides tne
necessary influx into the landfill Evidence of contamination is
clearly seen on both the east and west sides of the landfill which
reinforces the previously stated flow patterns
Of the several remedial measures reviewed the contouring and
grading of the landfill topcover and drainage swale provides the
most immediate protection The topcover has been graded mulched
and seeded to provide a low runoff slope generally to the east
The drainage swale on the left side of the landfill has improperly
graded sections which should be corrected Its northern section
could be drained into the northern sections swale and the southern
84
section drained to the southeastern section of the landfill Tne
point of the drainage swale which divides the northern drainage
swale from the southern one should be determined by a field survey
Cost is a major contributing factor when determining which
remedial measure is to be applied to the given situation For the
purpose of this report cost estimates are not presented but rather
the effectiveness and feasibility of the remedial measures are tne
primary considerations As was reviewed and simulated in the
computer models the slurry trench and impermeable cover over the
landfill are two viable options that would effectively provide
protection to the domestic supply wells in tne vicinity The
impermeable cover would eliminate precipitation recharge into tne
landfill yet drop the water table only a few feet due to upgradient
infiltration from the stream This would decrease the hydraulic
gradient thus diminishing the potential for a contaminant outflow to
surrounding wells The supply well of primary concern is one to the
west of Rose Hi l l Road marked well D on Fig 2 If contamination
occurs in this well the most effective measure would be to block
off leachate flow in this direction by installing a bentonite slurry
trench at the location indicated previously This would effectively
prevent leachate flow in the westerly direction and diverts it to a
more southeasterly direction In addition the slurry trench
precludes infiltration flow into the landfill from the upgradient
stream
85
Tnis report has effectively reviewed tne original ana existing
flow conditions and contaminant levels in the vicinity of the Rose
Hill landfill The purpose was to provide an understanding of
ground-water contamination patterns and study possiole remedial
measures
86lt
Appendix A
Precipitation Records
Monthly normal precipitation 1941 -197O
i$l Total monthly precipitation
KINGSTON RI
14
ia
^JO T I bullbullL
pound 111 laquobull
4
a
n
-
^
-
-
KS1JAN
^Ii R3 HB MAR
1
1 APR MAY
1
1 JUN
1981
JUL
-bullraquolaquo H
AUO SEP
K3~~f$s bull
_imdash
i1S 1
OCf NOV OtC
171 1 iI1
JAN HB MAR APR MAY
198
Fig 32 Precipitation Record
- - - -
IM 1 MtvJrflgtlgt c ortli-A t lUN I r nraquo rl - -
gt|MO CLIMATOLOQICAL OUSERV ATIONshyr-r bull JK gt raquo - 1
i5fWA I VAPOR Al IOH -bull AIM If MPCRATUM bullF 0 riccipn AT ION UNO IlMf
bull 14 H 14 H mdash Vshy ADDITIONAL DATA IfUAlUS OATt 1 bull raquof bull bull 1 ta
14 Hw rlaquo4 w bullbull bull 1 114 1mdash4 (llrl 1 1 1fl Hll
0 kmdash
Mraquo M4 raquo i T i 4 bullraquo-laquobull i i
Lgt f 1 21 S 1 Hbull - - bullbull -
ltJL 1 2 01 - - _ _ 1
mdash
-
1 12 _ Q I
mdash shy
mdash 4 (C ( - - fVi 1 - 0
1 (1
^ 1
Vvraquolaquo IJ1^ raquo CP O 3L 1 Z - i bull j-t-J
1 J
LH Vb T n 0
1 gt fl oo O ~l 2 L - bull 1 P )laquo jn iP IP - OOI L5L mdash shy
-t 84 ^(^^ ^fi P i flja 0 JO II 10 tl tcgt 7 J IV wllaquo
h l2L bull 0 lt -_ shy
-id VJ lt 3C 2 ft OOL -mdash
U 71 C1 Sr 2 13 2 nl JLJraquopound HP r M ltf1- (
IMe 2 ii O It
n jlt dl 1 1 bull o o-il ST i 1 i 25 2-x-1
-
ri
i tlL O mdash gtbull bullgtlt 1ft -o- is Oil So iJK 2-io otv u 31 fil loi 2 il Oll it Of wr is i1raquo -iZ 1 deg|0 01
M IT So - mdash
- 13 1 CT mdash i - mdash 21
shy
Tl Ci av ZUll IMT 0 IM Pe v _ 1) T) S) ii3( dlt Ii 2 lt^2 II li- S1 riivi To 7HX lt3lO 14 ^2- iTi I li 011 -- - -i -^IS no 5^ or i | T Jift laquoV OoH bullla It Va iCO mdash L OIL 11 bullvf poundgtpound lS_ flv oh P-lfe 1 poif _ shy11 IB kl (4 itlaquoT lamp llt0 oot^
mdash -n
It T1 |ir( L1 HI 2 0 oil
U 1M ft go C ICf^ -^2 Z laquo-|o
11 it 5 bulln - TO o abull Li u-i IT1 -- Iw O ltM (I bullbull bdquo-I(K 1mdash -tilltLlA ttfe
i Dgt ac -- U 44 4 11 1 1- ytd i i_i J-K 0 i if -i i i V t Wl raquoOHM 1-1 US D C P A R T M f N T OF COMMfRCE t 4 1 IUII 1 1 ^~) mdash
llaquo- Hi NC bull bullh bull bullJL^V HBl CO 00
11
)jLsVyr^gturv
^ | TKu
|-_t_ bull(
IIMgt I I Mt|UU III- II 11
PNECIPITATIOH
I 1 1 IMX
IMO
bull llfclaquo I UCIUKI) Ur C V A r U M A AHO CLIMATOUOCICAL OBitH
E V A F O R A T I C r i Jttffl laquo amp hMIlaquoJllaquoJIIlaquoBgt
DATE AOOITIOMAL DAIAKMAKk M
bullraquobullmdashlaquo
tp 01 (1 Of Ll OOI ooo
0^1 o-i 10 tl |00 102
OC (1 13 Ofl
it i rc DS os an
(1 SV o
Ul 010
(ISl 101 I on
130
II 5= Otl
ss lt 001 (IK Ml
jt il HIT
7 it
ow Wo 17 Top 2-01 OIO
(0 oov zi oot
u CO ^A 0 to Zoi CLflS
bull50 01 ljtj
nshy 5H LO OIt
50121 IVO QJO
14 Co Ho LO Hl ^pound Jl 1
ltM ool fllc
H Tl 01 II
11 11 Q1
iH OIO
HO 2 llaquol 11 II
lifc
IV-IIM ul OIPAITHINT or COHMIICC NOAA
NAtlOHAL gtIATnlaquoll raquotraquoVlClaquo CD
r~
All TCUMMATUNI ^V UII rgt ITmi 1 Cwphu Obic i gtn t ngir-H 30
rilCiriTATIOH
JJ T I rTJ-rimdashr-iramj|MP CLmATOLOQ
laquolaquo jftilCiii bullIHO
Oi1l ADOITIOHAL DAIAlllu
Ilf4ft
Sii1
(1 2 IO OO
Hl ii SO
us OIM
Q^L
a A3 Hi SZ Sf^ bull 12J2
HI Z-SF OOl 1C t HM IA H ICP fiJA
OOl 10 (310 sn 310
if HI (0 ^01
bullit SO 28H poundJ1 11 006
14 35 TX oon II (bull2 it zr II c-S
rr Zll lo 31 OP an 31 a 31 oor
CSW O-ll Si CC Of 011
Oll _ I |ft
00
u i oerraquolaquoTMiMr of c NOAA
NATIONAL K C A T N C M SCMVlCC
TC^S lk)oiVroTJA
TETT I 7X
1raquolaquolaquo 4 bdquo ir lt er ni I^OV ltqgl j--^ TQ
MICiriTAllOH ITIND
D|mdash
b5NO ctiUATOtoiCAL oeit^
OATI AOOITIOMAL OATAVlHAtt
0-tt
Mlaquoh bullbullbull- rshy laquo
I- ltltriu HI I 4 bulllaquobullbull1
Zii
30 Dfellt otvt
at HA
OOI
62
iJ_S2 HI if
bull- 20 SI 2i So
So
VVfr
OSfc
I (
Jtlt
3aoi
r j -bull ie MA
Irill iiol
in^ 14
Mo
Zll
214
21 1P
00-i
bulliron
17
bullr
11 i ir- I J Ktf^c
US D E P A R T M E N T OF COuMEDCC I | C gt A A
K AIlaquo Ttupf lATuit r
|SlVi AlJ PIICIPITATION
oJud (El
VIM i Uraquo
MIND E
EVAPORATIOH flnrft bull A ftufiifccdll
KECORO OF eVAPllHAtlil bull I CLIHATOLOOCAL OBSERVA ^Hij
14 MM A_M AOOIIIONAL DATA11 MAIM
Mr bullH Oo|
M Si lift
bull221 IHI
ZS Ji 40 IZV
icr KS I
HZ 111
bullT 21
loA UK JA IP
v^ ft
1M 2Sshy IT Tl
71 V |
i I 31 1deg a
uty^ U bull3
ons 1 CiO TxX
HHO (10
3H 19 12 10 IP
raquo3H raquo | 5t io
OP OIT
14
vO UI Of PANTMINI Or COMMCRCf MM O A A
F ngt TIHH
iiicffwiffc 4 rJ (TIM bull Cempltit Obitittiio
AIlaquo TIMHIATUM PHICinTATION I V A f OK ATlPrl
OATI ADDITIONAL DATA KMAlIt
U4laquo4 +
03H Ji
10
rc a 1 16 oi ii
tiiy 10
OI
II i23 or o 13 -y~ou HO
II 3V III i 3 t
V laquop oot
OM1 SS ne
T an -i IP
Olt zr LTV
3T 001
a -11 2T
10 an 31
-1 raquo 131 UP 3H lf 14 Lpoundshy
it 14 30
IS
Ui O I P A K T M f H T OP COWlf ICfM O A A
NATJONAI V C A T M C n f t K M V l C K
bullbullbullbullbullshy -2 o AIlaquo TIMMRATUM f fKICIPITATIOH
OATI poundt- MMINMAL DATAk
ZP 51 lo icr
011 111
OoT IHf
Ut 003 am
3o 13 ao
4A X 05shy
H4 i IjJyiV131 ooc js
IH oi 01 tL 18 13 a
No 11-7
rivgtp OO| M Hi 03 01
It 12
bull I 41 bull7119 14 ^^ raquo 31 15 lampk n M ho i
Jo -j-
-J
I
Ml H^ I _
amp2ampUi^= LS 0 S 0-f bullTTT
-Vmdash gt U_ bull 1 rOHM I- 11 OI OCPARTMlNT OF COMM(NCC
HO NATIONAL W f A T M f H ftfraquoVlCI
98
Appendix B
Boring Logs
99
X iHECT 1 ff 2
OAT American Drilling amp Bor ini I Co Inc
wo WATH smn EAST PR ov IDENC E ft 1 Town of South Kingstown South K ngstown R I MOLENO X-J
TC 100 RCSS bull ujrMonitorinq Well Installation | South Kinqjtown R I UNC a STA Pf KXICCTHJ LOC ATK3N
bull cfrserrr TO above S MPLES S FNTTO _ _ |laquolaquor A-109 SURF ELEV RE PORTSEr
GROUND WATER O6SE RVATC MS 1 CDREraquolaquo m-T nn75 laquo A 256 - 20 mdash Hew y
Instolled 32ofT-l2 PV C - JO- COMPUTE 111275 K toia 3- I-WI 1-38 TOTAL MRS bdquo10 screen BORING FCACUAM J K lanq MAI rraquo HomnwWI 300 140 IampPCCrc Mamlaquor Fall 24 30 lampaaiona SOLS ENGR
LOCATION OF BORING H ONITOKING WELL
Coung Samplt Tjp Blow per 6 Manure SOU IDENTIFICATION Strata SAMPLE ^^^yV Bloot
foot
Otptni
From- To
el
l
on Sampler
0-6 1 -6-13 12-18
Dentity or
Conmt j
Chang Remark include colo^ graaation Type of tod lie Rao-coMr type condition nordshynetiDntotf time leamt and tie No Pen Rtlt
2 No top sample 5 12
1 loamy fine sand
bull)^ 40 30 36
5- 616 0 23 20 16
noist iense
Brown fine to coarse SAND some fine to coarse gravel Trace silt
^
1 18 18
36 8-0shy57 40 30 V 35
|0-||-6 D 14 24 20 Srown medium to coarse SAND Some fine gravel cobbles
7 IRshy 16
27 75 37 3
IS- I- D 5 14 16 3bull
ISshy 15
42 50 I9--0shy50 65 20-2ll-6 D 9 23 26 bull Jrown fine to coarse SAND Tbullwshy 1Z 75 90
22-0 Trace silt trace fine gravel
124 120 74 60 52 41
7S-ltlaquoil-A DX 71 16 13 wet very dense
Gray-brown fine to coarse SANC Some fine to coarse gravel little silt
H IR u
40 30--0
3C-30-IO
3l4-334
334-3314
38 4-434
D
c
C
C
7 IflO
94 6
we tr j
y se
ft irox
30MOshy
31 -4shy
Gray-brown fine to coarse SAND Trace silt
Gray-brown fine SAND some lilt trace fine gravel
Too of Rock 31 -4shy
Gray-pink GRANITE
6 7
amp
CJ
IltJ A
60
601
IQ mdash
2(
4
5 i Hard
ft 5ome seams bull
GROUND SURFACE TO J 4 U3CD_ ^JVrf bullbull( tutu t to 4o 4 SampM Type Proportion UMd MOB Wtx 3 OfaM on 2OD Sampler SUMMARY-
OOry CCartd WltWen4 Hoc OlolO Canmonieraquoi Don any CoKeem CarMWncy Earm Barrlaquoj 11 14
UPgtUnOigtturod Piuon trite (Oto20dego 0-Kgt Loei it 0-4 Sait 3O+Hofd Rock Corng 14 Kgt-30 laquo4 0 rte 4-8 MSHM Samplet TPTtitPit Ai Auger Vvanefett tarn 2Olo39 3O-M Owlt n laquo-lS Strlf rinit nn v 1
UTiUndlshffbed ThrMOll and bull 33to9O 5O Very 0laquo nraquoe 19-30 V-3trraquof - | OLE NO X-l
TOVH rim - iA it raquotoraquo
100
SHEET 2 o_L
WO WATEt STUET [AST ft OVIDENC pound a i American Drilling amp Bor ing Co Inc
MCLl WQ X- 1 Tt AOORCSS i
LIME A STA KXICCTMJ tuf same as 1 | tame as i LOCATION
W PORTSEf mo OB nj urt eflaquo T
illtPLES S
P
CVTTO nlaquo mun orv
^s f^ Tin i GRCVMO WATER OBSERVATONS CASING SAMPLER CORE BAR
START Typi COMPUTE tome at 1 same aiH
TOTAL MRS BORIMG FOR CMAN n bull IT INSPECTOR SOILS EMM
LOCATION OF BORING u HfVJTneTfi UFI _
8
Counf Blo-t
foot
Dtpllo
From To
0( on SampMr
0-6 f 6-IZ
Moittir
Oonuty or
Contilt
Strata Ctnngc
SOIL OCNTiriCATION Rtmorkt ineHifl cotot grqdotion Typlaquo of Mil etc Roo-axtrPlaquo condition Mrdshynlaquot Drog tun ttomt end tic
SAMPLE
No Ptfl RfK
434-4o4 c
approx 7 minj
per toot 454
Gray pink GRANITE Hard Fairly solid core
lt_4 24
Bottom of Boring 45 -4
-
~
bull 1
GROUND Sorrow Tye
SURHCZ 10
bull OiOry CgtCord WWothod UPUnditiurMd Piston TPlaquoTtraquotPtt AtAuotr VVor
UTltUndinrvd TTMMO bull bulltat
iivnPilaquo(onioni Uraquot4
me OioiOItttt laquoraquo20
wmt Z0ie33
and 361090
c M
C1 5 Si
-SOshy
ASING
IOtgtWtigt bullnlot Dn 10 Loci M Mod 04 SO Dm 1shy Viry 0laquo
s _
TMEN 0 hMl on 200 SoiTBUr laquoity ConcMMt Conorawncy gtbull 0-4 Sort 30shym 4-B MStlfl M BH9 Strtf bull ts-so v-swt bull
t-HOrt Ear Bern RoetCorrt
i ^^^^^ bull
-[MOLE no x-i
101
raquoMEC rAmerican Drilling amp Bor in g Co Inc 1 ofj_ DATE wo WATlaquo smn UST Plaquo IOIDCNC j laquo i
Town of South Kingstown South Kingstown 8 MOLE MO Jlt Z TC rx MCS3
rtprr uAurMonitorina Well Initollation | South KinqitowrxRI UNC A STA P KATIOM ME POCT ^rwT TO above I OFFSZT
uD^r laquorlaquorTTO 6 -109 suw tLEv Sgt louffJOCNO
0 tj Tlmlaquo WOUND WATER 06SCRVATC US gtW Rsdl SING SAM^EH CORE BAH
26 ^_ 12 $TAlaquoT UL 2Z2i Ji r TTP NW ltA sr IJZC Z5 CCOMPLETE
SitLO 3 I-3B- 1-38 TOTAL MAS 41 BOAINO FOACMAN JK1 ana nf ni n MonwwWl 300^ 140 BIT bullK^CT
gttonvrar Foil J^laquo 30mdash Diamond SOOJIEMGM
IE HFII
iCaunq SampM Trplaquo BMMtpw6 UOIIIK- SOIL DCMTIFKATION Siraia SAUPLE Blow DlaquoPIAraquo of on SompMr HtmorU mcJuo cotes gradation Type of Dwuily
pw or CXang writK Roel-eolorlyp condition tvort-From- To Vfoot 0-6 f 6-2 12-18 Coniitt egt rwtiOnAngtimt wamaondtte No Praquon Rtlt
2 Brown fine SAND little silt 2 2-0shy5 15 18 moist Browi fin to coarse SAND 18 5- 6-6 0 14 25 27 vlaquo Troc fin aravel | 25 wy Ifl 11
dlt tns 35 40 38 moist n in-il-i Lgt U 15 18 ie is li1 Irl IS 31 I2-0
~~43 1
A) Jrown coars to medium SAI MD 48 moist Little fine to coarse gravel
|5-IA-Xlaquo 14 47 41 fn D laquo y Little silt rrqa coarse sane 3 18 I1
68 In IS 44 32 34
n ^n-^i-A- w 2o 19 29 wet 4 la -59 lens ltfO no
25-0 2amp bulllaquo- 77 c BOULDER r[ 4 i
27-0 5X ~W 24 24 bullWar- 5 Ifl irown tine to coarse SAND some
dens 29-0- Fine-coars gravel trace silt
30-3I oxx 30 32 30 moist irown -gray fine SANDiom e 6 l rr Vlaquoy 31 -0 silt trace fine oroveTILL
Bottom of Boring 31 -ampbull shyBent casing -pulled out and moved over 4 - washed amp tJrovlaquo casing to 30 -Installed 3C gtof 1-12- PVC - 10 screen
WOUND SUraquoraquofCE TO 3pound 1 yijfD MW t ASIMC TMCJ laquo olaquorod -bor of borina
SomoU T]Fplaquo ProigtuliOraquoH UMd MIOtgtWLx3Orolt lon2OASanlaquoMr SUUMARY-D=Dry CCorad Wlaquoworaquonraquod bullact OiaiO CanM gnMM Daonty CIMIH Caamraquoci EffW 8or^ 2pt
UPiUnairurMd Pition Itnt laquoM2O O- O UKraquolaquo 0-4 Soft 3O-hHard Roelaquo Corrig o- JO M0mlaquo 4-8 MSNff SOTipM 1 p^ 3O-9O OwgtM bull-IS Slid
TPlaquoTraquojraquoPit AAugtr ViVon mini tamt 20to39 UTtundiifir6d TrwMOtf and JSloSO 50-raquobull Vary 0nlaquo [HOLE NO x-2 B-3O V-3Mf lev rim - IAIT raquosectlaquoraquo
102
300 iu 24
1 UMnii ffi 140 laquo 30
CA1INC tf
gt taWCTf
bull 0gtlaquo i R Cook Jr_ R Millineton1 Wttn
I~
1 VAMtl CtMG
1 W HO-t MO
1 Oraquo 1 laquo0~ twt
L 1 laquo-raquo VfcM^lf [wlaquoraquoCI ^ ^ K3Ot III laquo
0-LS D
5-65 D
LlQ 10-115 D
15-16 Tgt
Lraquo 70-51 n
25-26 D
F
I O-O Ci
A Allstate Drill ins Co vi o i
PROVIDING R 1bull raquoraquo uvraquonn~ N M O M I T O P I N G HE1 _^lt -^ PI-Traquo UJU
CUM Town of South Kineraquotown raquoraquo 1 1TA maoer Propolaquolaquod Sit for Slude Disposal nltn
laquo V-449 iampAAtut i a 138 ort STI bull r 42777 CtOuMO IKVtllON
Cill bdquo 258 DA II MN ru 42777 rilaquolaquodO laquoraquoTti rum 1911
AU1TATI
MMUI1 raquolaquogtlaquolaquo laquoKiO itXHHKraquoriOi of sous MUAHI nMTKlion Ot CMlaquoMC|kOraquort tl CO~VH DXltgt raquomlaquo laquotf IMi COIOI C4l II I 1raquo gtlaquo^ Oraquo 1Ol rC t Xgttgt VtfKOe Craquo Mi 1 ft liMraquoK laquo0^tlaquot nfgt
1-2-1 10 TOP SOIL FINE LIGHT BROWN SAND traclaquo of ilt
16-31-17
22-24-21 100 FINE TO MEDIUM LIGHT GRAY SAND trace of fine gravlaquol and raquopoundLt
lfl-37-34 150 LIGHT BROWN FINE TO MEDIUM SAND little poundinlaquo gravel
21-17-15 200 MEDIUM TO COARSE SAND bullomc fine gravel
12-4-10
265
Observation well installed
NOTE No casing blows taktn
bullbull B-23 ow
^w^ 265 I raquo bull raquolaquo bull I W
11 laquot gtbullraquo Vlaquo 14 W gt_ c-shyji bull alaquo bull jraquo VI laquoHshyw bullbull m raquobullbull D-6 raquo Mshy
bull bull laquo Vshy
1
bull bull
I
103
MAMMII Allstate Drilling Co ulaquorr 1 or 1 FftOVIOCKZ H L traquolS mTArm^S MONITOR NR WEL
VNO wr3JJO__raquoraquou_24__ HCU MO P-74 n iu riBwi Town of Slt7H^ Xirpin
mdash^ laquo0J P 1 1 bull ^n^ciit^o TVlaquow^laquott1 bullraquoit wt 140 nu 30 olaquor fBu lkv Waste Disposal Arcai
MUTAH a V-449 R Cook Jr UMlaquoiigti D 1 38 0t| raquoIJ raquo 5277 rlaquo SUMO luvlaquorv-laquow
mdash 5277 fipe -raquoT pfpm 150
H MCIO IMNTlXAflON Of SOU t(kAIlaquoS rrn 0-laquoraquo
5 -SF 01 w in laquobull -raquo ^ lit
D 1-2-2 TOP SOIL V-1-oraquo
15 IPbull FINE TO MEDIUM LIGHT GRAY SAND AND GRAVEL
5-65 D 37-27-35 some silt
10-11 D 20-14-18
15-165 D i 17-14-14 155
BROWN COARSE TO MEDIUM SAND little fine to coarse gravel trace of silt
20-211 D 4-4-2
230 GRAY BROWN VERY FINE SAND
25-26J D 7-8-9 AND SILT 265 fvarvedl
Observation well installed
NOTE No casing blows taken
wta 10 n uuraquo c^imdashbull IgtM laquolaquobull- B-24 ow ~ 14 ltfc laquoraquobull vlaquo^ M laquobull r O 0 fmtt bull W-L 26 5
-0- CgtCmdashgt bull laquolaquobull mdash laquo 1 - raquoraquo 1 gt 1laquo bull 1 gtraquor to bull mdashbull bull bull bulllaquo I t l~laquo 1lt Uraquo mdashbull ) bull 1 gtbull ft 0~ H laquoy bullM ta bull -IN la laquobull OPUM bull($ IMI
mdash H raquo laquo-bull
104
Appendix C
Calibration of Specific Conductance Meters
105
Specific conductance measurements were made using a beckman RB
338 temperature compensating meter and a YSI rtooel 33 salinity
conductivity temperature meter The YSI meter is not
temperature correcting A formula to compensate for temperature
differences to standardize YSI measurements was used (21)
A long probe for the Beckman meter was used to measure conductivity
in the wells Differences in conductivity between the YSI ana
Beckman meters and the Beckman short and long probes exist These
were calibrated in the laboratory using 001 N and 01 N KC1
solutions Values presented are Beckman short probe values The
Beckman long probe values were reduced by 76 and tne YSI values
were multiplied by 11 to adjust to Beckman short probe values The
YSI meter was used in the latter phases of the study for the
stream contamination due to the greater accuracy of the dial readout
scale
Table 7 Specific Conductance Meter Calibration Table
Concentration (KCL) 0001N 001N
Specific Beckman short 145 143 143 1247 1245 12GO
Conductances Beckman long 190 191 188 1639 1650 1665
umhocm 9 25 C YSI 132 131 128 1131 1140 1150
average values Beckman shortBeckman long = 075
Beckman shortYSI = 11
106
Appendix D
Computer program Flow Chart
107
F1g 33 Computer Program Flow Chart-
1TpoundR MAP TCO
NEWPER
WEWSTP CZAX
HEWIT TRANS TCOF ROW COLUMN
Yes
Yes
108 The following is a description of the USGS two-dimensional computer
program Iterative Digital Model for Aquifer Evaluation updated
December 1972 by P C Trescott The program written in Fortran
consists of a MAIN program and six subprograms or subroutines which
themselves are organized into subprogram sections The subroutines and
their sections are listed below
MAIN Program
DATAIN (subroutine) COEF ITER (section) CLAY MAP TRANS NEWPER TCOF
ETRATE COMPUT STORAG
NEWSTP LEAKAG NEWIT1 NEWITO CHECK ROW CWRITE COLUMN STEADY PRNTA OUTPUT DRY BLOCK DATA
The program begins in the MAIN program which controls the sequence
of passage to the subroutines Sequential steps are described in the
program as shown in the flow chart of Fig 32 Emphasis is placed on the
steady state confined aquifer case as applied in this study First data
input is read in the DATAIN subroutine This data includes transmissivities
or permeabilities starting heads storage coefficients and grid spacings
Nodal transmissivity values are then computed for the water-table problem
in the TRANS section (COEF subroutine) This procedure is necessary here
because the subsequent routine for computing iteration parameters (ITER)
keys on nodal transmissivity values which would not have been input to
the water-table problem In the water-table option these would have been
109
computed from given bedrock and water-table elevations to obtain the
saturated thickness component of the transmissivity calculation In this
study water-table option was not used and the transmissivity values were
input directly The program then passes to the ITER section (DATAIN
subroutine) to compute the iteration parameters which expediate or even
cause convergence Next the MAP section (DATAIN subroutine) is utilized
to initialize data for an alphanumeric map if this was requested in the
input options Transmissivities are then computed for the confined
(artesian) aquifer case (water table not specified with input options)
in the TCOF section (COEF subroutine) These coefficients are harmonic
mean values of adjacent nodal transmissivities weighted by grid sizes
Time parameters and pumping data for a new pumping period are then read
in the NEWPER section (DATAIN subroutine) followed by entry into the
NEWSTP section (COMPUT subroutine) which calculates the size of the
time step Leakage coefficients (hydraulic conductivity of the confining
bed divided by confining bed thickness) are next computed in the CLAY
section (COEF subroutine) if leakage was specified in the input data
which was used in this study
A new iteration is then initiated in sections NEWITO (COMPUT
subroutine) NEWITO saves the current head values and compares them to
the updated head values for determining closure This is followed by
nodal transmissivity values being computed for the water table or water-
table artesian conversion problem Transmissivity coefficients are then
computed for the water-table problem in TCOF (COEF subroutine) Total
head values are then computed with the alternating direction implicit
procedure using the Thomas algorithim first along rows in the ROW section
110 and then along columns in the COLUMN section both in the COMPUT subroutine
Then if a solution is not obtained (because the error criteria for
closure is not satisfied) the MAIN program branches back to NEWIT1 subshy
sequent sections TRANS TCOF ROW and COLUMN repeatedly until a
solution at the particular time step is achieved NEWIT1 increments the
iteration counter and is immediately followed by NEWITO The program then
moves to the STEADY section of the COMPUT subroutine to check if the
closure criteria for steady state has been satisfied Output is then
printed in the OUTPUT section of COMPUT if steady state has been reached
or if the particular time step is designated for output
The program then branches back to NEWSTP (COMPUT subroutine) and
moves through the subsequent routines until the last time step in the
pumping period is reached Output is then promoted in the DRY section
of COMPUT if specified in input data If the last pumping period in
the problem has not been reached the program branches back to the
NEWPER section and moves again through subsequent sections otherwise
the program will terminate or start a new problem if one follows
This study was simulated as a steady state problem which can be
simulated by setting the storage coefficient of the aquifer and the
specific storage of the confining bed to zero and using one time step
of any length
111
Appendix E
Computer Data Sheets
RGSEA
10 ROSE HILL LANDFILL MODEL 20 30 40 LEAKAGE 50 60 70 CHECK 80 90 100 HEAD 110 120 1 23 IQ 100 5 001 37E-OU 0 130 100 001 0 0 1 4 0 - 1 - 1 1 - 1 - 1 i i i i i i 1
ISO 1 10 0 1547E-05 01 10 1 1 160 04642 200 200 1 1 i it
1QO 190
CARDS I THROUGH 19 - CODING SHEET
CHEAD
100 110 120 130 131 132 140 141 142 150 151 152 160 161 162 163 164 165 170 171 172 173 174 175 176 177 178 179 1BO 101 190 191 192
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 539
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 25
25 58
25
25
25
25
25
25 621
25
25
25
25
25 662
25 25
25
CARD SET 2 - STARTING HEAD MATRIX (FT)
193 194 IVb 196 197 190 200 201 202 210 211 212 220 221 222 223 bull 224 225 230 231 232 233 234 235 236 237 23B 239 240 241 250 251 252 253 254 255
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 23 25 25 25 25 25
25 25 - 25 25 25 25 25 25 25 25 25- 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 - 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25
25
25 25
25
25 25
25 25
25 25
25
25 25
25
25 25
25
25
25
25 25
25 25
25
25 25
25 25
25 25
25
25
25 25
25
25 25
CARD SET 2 - STARTING HEAD MATRIX (FT) - continued
STORC 1512 FRI 19 FEB 82
100 110 -1 -1 - 1 - 1 0 0 120 130 140 ISO 160 170 100 190 200 210 220 230 240 230 251 260 261 262 263 270 271
CARD SET 3 - STORAGE COEFFICENT
LEAK
100 110 120 02 130 _ 18 02
I ltu 18140 025 150 02015015015 19 deg25
02 160 022 bull-laquo- J1 5 j 1 z laquo- l^
170 015 180 016 laquo02
190 016 OE025
200 02504019022021025 2 5 i S lt03 0252i2 n
230 030 deg23 deg2 deg2 deg2 -02023023 240 022 250 022025025 02
027043 013025
30() 025025025 310 025031 320 024025
CARD SET 5 - AREA OF STEAMBEDAREA OF NODE
120
Appendix F
Bibliography
121 BIBLIOGRAPHY
1 Agpar MA and 0 Langmuir Ground-Water Pollution Potential of a Landfill Above tne Water Table Groundwater V 9 No 6 1971 pp 76-96
2 Allen William B Hahn GW and RA Brackley Availability of Ground Water Upper Pawcatuck River Basin Rhode Island USGS US Government Printing-office GS 66-624 19bb
3 Annual Book of ASTM Standards Part 31 Open Channel Flow Measurement of Water and Waste Water by Weirs D 2034-68 1975
4 Annual Book of ASTM Standards Part 19 Infiltration Rate of Soils in Field Using Double-Ring Infiltrameters D 3385-75 1975
5 Baeaecner MJ and W BacK Hyarogeological Processes and Chemical Reactions of a Landfill Ground Water V 17 no 5 1979 pp 429-437
6 Beck WW Dunn AL and Grover H Emrich Leachate Quality Improvements After Top Sealing1 8th SHwRD MERL Symposium 1982
7 Beckman WK Transient Modeling For Estimating Sustained Aauifer Yield master thesis presented to the University of Rhode Island Kingston RI 1978
8 Bhattacharya PK and HP Patra Direct Current Geoelectric Sounding Elsevier Publishing Co New York 1968 135 p
9 Bouwer H Ground Water Hydrology McGraw-Hill Book Co New Yoric 1978 p 378
10 Braids 0 Cocozza pound Fenn D Isbister J Rous P and B Yarc Procedures Manual for Ground Water Monitoring at Solid Waste Disposal Facilities Environmental Protection Agency530SW-611 Cincinnati Ohio 1977
11 Cartwright K and MR McComas Geophysical Surveys in the Vicinity of Sanitary Landfills in Northeastern Illinois Groundwater V 6 no 5 1968 pp 23-30
12 Cartwright K and Fd Sherman Jr Electrical Earth Resistivity Surveying in Landfill Investigations Reprinted from Proceedings of ohe lOtn Annual Engineering and Soils Engineering Symposium Moscow Idaho 1972
122 13 Clark TP Survey of Ground-Water Protection Methods for
Illinois Landfills Groundwater V 13 no 4 1975 pp 321-331
14 Dunne T and LB Leapold Water in Environmental Planning WH Freeman and Company San Francisco 1978
15 Faro DG Upgrading Hazardous Waste Disposal Sites Remedial Approaches US Environmental Protection Agency500SW-677 Cincinnati Onio 1978
16 Fenn DG Hanley KJ and TV Degeare Use of the Water Balance Method for Predicting Leachate Generation From Solia Waste Disposal Sites US Environmental Protection Agency530SW-lfa8 Cincinnati Ohio 1975
17 Geisser 0 An Electric Analog and Digital Computer Model of the Chipuxet Ground Water^ Aquifer Kingston Rhode Island master thesis presented to the University of Rhode Island Kingston RI 1975
18 Hahn GW Groundwater Map of the Narragansett Pier Quadrangle Rhode Island Rhode Island Water Resources Coordinating Board GWM 5 1959
19 Hemsley William T Koster C Wallace Remedial Technique of Controlling and Treating Low Volume Leachate Discharge USEPA National Conference on Management of Uncontrolled Hazardous Waste Sites Oct 1980
20 Hughes GM RA Landon and RN Farvolden Hydrogeology of Solid Waste Disposal Sites in Northeastern Illinois Final Report to US Environmental Protection Agency PUD SW-l^d Cincinnati Ohio 1971
21 Keller GV and FC Frischknecht Electrical Methods in Geophysical Prospecting Pergamon Press New YorK NY 19bb
22 Kelly WE West Kingston Landfill An Evaluation of Its Effect on Ground-Water Quality Rnoae Island Water Resources Board Water Information Series Report 1975
23 Kelly WE Geoelectric Sounding for Delineating Ground-Water Contamination Groundwater V 14 No 1 1976 pp fa-10
24 Kelly WE Ground-Water Pollution Near a Landfill ASCE Environmental Engineering Division Journal V 10 No EE6 Dec 19b pp nay-nyy
25 Kelly WE personal communication January 1982
123
26 Kelly WE and OW Urish A Study of the Effects of Salt Storage Practices on Surface ana Ground Water Quality in Rhode Island NTIS FHWA-RI-RD-8001 1981 54 p
27 Kimmel GE and OC Braids Leachate Plumes in a Highly Permeable Aauifer Groundwater y 12 no 6 1974 pp 388-393
28 Klefstaa G Senalein LVA ana RC Palmauist Limitations of the Electrical Resistivity Method in Landfill Investigations Groundwater V 13 No 5 1975 pp 418-427
29 Landon RA Application of Hydrogeology to the Selection of Refuse Disposal Sites Groundwater V 7 no b 19b9 pp 9-13
30 Lang SM Bierschenk WH ana WB Allen 1960 Hyaraulic Characteristics of Glacial Outwash in Rhode Island Rhode Islana Water Resources Coordinating Board Bulletin No 3
31 LeGrand HE Patterns of Contaminated Zones of Water in the Ground Water Resources Research v 1 No 1 1965
32 Palmauist R and L Sendlein The Configuration of Contamination Enclaves from Refuse Disposal Sites on Floodplains Grouna Water v 13 no 2 1975 pp 167-181
33 Pinder GF A Digital Model for Aauifer Evaluation Techniaues of Water Resources Investigations of the US Geological Survey Bk 7 Cl 1970
34 Purushattam D Tamxe GR and CM Stoffel Leachate Production at Sanitary Landfill Sites ASCE Environmental Engineering Division Journal V 103 no EE 6 Dec1977 pp 981-988
35 Remson I Fungaroli AA ana AW Lawrence Water Movement in an Unsaturated Sanitary Landfill ASCE Sanitary Engineering Division Journal v 94 no SA2 April1968 pp 307-316
36 Rosenshien JS Gouthier JB and WB Allen Hydrologic Characteristics and Sustained Yield of Principal Ground-Water Units Potowamut-Wickford Area Rhoae Island USGS US Government Printing Office GS 67-324 1968
37 Roux PH and B Vincent Electrical Resistivity Evaluations At Solid Waste Disposal Facilities US Environmental Protection Agency SW-729 Cincinnati Ohio 1978
124
38 Salvato JA Wi lk ie WG and BE Mead Sanitary Landfill Leaching Prevention and Control Water Pollution Control Federation Journal v 43 no 10 Oct 1971 pp 2084-2100
39 Sawyer CN and PL McCarty Chemistry for Environmental Engineering McGraw Hill 1978
40 Stellar RL and P Roux Earth Resist ivi ty Surveys - A Method for Defining Ground-Water Contamination Ground Water v 13 no 2 1975 pp 145-150
41 Todd OK Ground Water Hydrology John Wi ley and Sons Inc New York 1959
42 Tolman AL Ballestero AP Beck WW and GH Emrich Guidance Mannual For Minimizing Pollution From Waste Disposal Sites US Environmental Protection Agency-500SW-677 Cincinnati Ohio 1978
43 Trescott PC Iterative Digital Model for Aauifer Evaluation US Geological Survey Open file report 1972
44 University of Rhode Island Academic Computer Center CalComp Contouring Manual
45 Warner DL Preliminary Field Studies Using Earth Resistivity Measurements for Delineating Zones of Contaminated Ground Water Groundwater v 7 1969 pp 9-16
46 White EF A Report to the Town of S Kingstown Utility Survey Engineering Corp 1967
47 Zohdy AAR A Computer Program for the Calculation of Schlumberger Sounding Curves Over Horizontally Layered Media Using the Method of Convolution US Geological Survey Denver
48 Zohdy AAR Eaton GP and DR Mabey Application of Surface Geophysics to Ground-Water Investigations Technidues of Water-Resources Investigations of the US Geological Survey Book 2 Chapter 01 Washington US Government Printing Office 2401-02543 1974
