Phosphorus Loads Upstream (Arkansas) and Phosphorus Loads Upstream (Arkansas) and Phosphorus Loads Upstream (Arkansas) and Downstream (Oklahoma) Of Lake Frances:Downstream (Oklahoma) Of Lake Frances:Downstream (Oklahoma) Of Lake Frances:
Are Differences Due to Are Differences Due to Are Differences Due to Monitoring Program Design, Natural Variation, Monitoring Program Design, Natural Variation, Monitoring Program Design, Natural Variation,
or The Lake?or The Lake?or The Lake?
Thomas SoerensThomas SoerensThomas SoerensUniversity of ArkansasUniversity of ArkansasUniversity of Arkansas
Acknowledgements
GimGim GohGoh, UA Civil Engineering, UA Civil EngineeringBrian Haggard, UA/USDABrian Haggard, UA/USDA
OutlineBackground and historyBackground and history•• Illinois River in Oklahoma and ArkansasIllinois River in Oklahoma and Arkansas•• Lake Frances Lake Frances
Possible differences between AR and Possible differences between AR and OK loadsOK loads•• LakeLake•• VariationVariation•• Monitoring programMonitoring program
Summary, conclusions, futureSummary, conclusions, future
Oklahoma and Arkansas
Linco ln
Fayetteville
Springdale
Rogers
SiloamSprings
W estville
S tillwell
Ark 04A
Ark 05
Ark 06
Ark 06A
Ark 07
W atts
Kansas
TallequahEldon
Oklahom a Arkansas
W ater sam pling sites
Illinois River in Arkansas-Oklahoma
USGS 03-4168
Lake Frances
Lake Frances
AROK
AR hwy 59 sampling site
OK hwy 59 sampling site
2.5 km
Loads upstream of lake different than loads downstream?
Illinois River - background
Designated as an Oklahoma scenic riverDesignated as an Oklahoma scenic riverIllinois River and Lake Illinois River and Lake TenkillerTenkiller in in Oklahoma are major recreational areasOklahoma are major recreational areasImpacted by point sources and Impacted by point sources and nonpointnonpointsources in Arkansassources in ArkansasLawsuit between Oklahoma and Arkansas Lawsuit between Oklahoma and Arkansas reached the U.S. Supreme Courtreached the U.S. Supreme Court
Background: Illinois River - LawsuitOklahoma sued Arkansas (1986)Oklahoma sued Arkansas (1986)•• to stop Fayetteville dischargeto stop Fayetteville discharge•• U.S. Supreme Court 1992:U.S. Supreme Court 1992:
–– AR must meet OK water quality standardAR must meet OK water quality standard•• No P limits in Arkansas except FayettevilleNo P limits in Arkansas except Fayetteville
–– ARAR--OK Arkansas River Compact CommissionOK Arkansas River Compact Commission•• oversees agreementoversees agreement
Compact commission recommendationsCompact commission recommendations•• Arkansas Reduce Phosphorus by 40%Arkansas Reduce Phosphorus by 40%
–– use avg. load from 1980 to 1993 as baselineuse avg. load from 1980 to 1993 as baseline–– use 5 year moving use 5 year moving avgavg
•• Note: lawsuit began over point sources, focus has Note: lawsuit began over point sources, focus has shifted to shifted to nonpointnonpoint sourcessources
Northwest ArkansasAbundant water resourcesAgricultural productionPopulation growthUrban development
Agricultural Productionin NW Arkansas
Lake Frances - History1931 – wooden dam completed, resort opens• golf, tennis, swimming, horses, boating, dancing, fishing
1943 – embankment partially washed out1954 – Siloam springs purchases lake, rebuilds dam, builds treatment plant1971 – concerns about lake water quality1977 – Lake “in late stages of eutrophication”
1978 – concerns about safety of damEarly 1980s – Fayetteville, AR proposes WWTP discharge into Illinois River1983 – Lake Frances clean lakes study• Point sources = 65% of P load
1985 – study it again.
Lake Frances - History
1983 Lake Frances study
Total P “declines only slightly” between Total P “declines only slightly” between upstream and downstream stations.upstream and downstream stations.Form of total P:Form of total P:•• 85% in reactive form upstream85% in reactive form upstream•• 54% in reactive form downstream54% in reactive form downstream“…sedimentation is eliminated as a “…sedimentation is eliminated as a major net phosphorus sink.”major net phosphorus sink.”Study focused on Study focused on baseflowbaseflow
1985: “…officials were urged … to ensure that special interests don’t influence the results of two studies…”
1985: “…challenged what he called omissions and discrepancies in the studies and urged that differences between the studies be reconciled…”
1983: “…60 to 90 percent of pollutants in Lake Frances come from (Arkansas) plants’ discharge…”
1983: “…estimate was flawed by faulty sampling methods and did not give enough blame (to NPS)…”
Lake Frances - HistoryLate 1980s –
March 12, 1990 Article…
Lake Frances gets really nasty• shallow and mucky, boats running aground• Algae in lake and downstream• EPA study: “…Lake Frances outflow was the most
turbid water sampled in the Illinois River Basin.”
Dam is unsafe. Court order to repair dam by July 1, 1990
The Oklahoman, March 12, 1990
“shallow, polluted mud hole”
“…creates a foul odor and clouds the Illinois for 12 miles”
OSRC: “… have Lake Frances declared a public nuisance and drained. … either fix it or take it out.”
“… dredge it…”
“… open the gates…”
Lake Frances - HistoryMay 4, 1990 – Dam busts• Top several feet break off
Lake Frances – before 1990
Lake Frances – after 1990
Lake Frances – after dam break
What’s happening in “lake”now?Lots of nutrient rich sedimentLots of nutrient rich sedimentPhosphorus flux?Phosphorus flux?
Why would lake make a difference?P source or sinkP source or sinkBallard Creek (~10% of flow)Ballard Creek (~10% of flow)•• Unnamed creekUnnamed creek
Illinois River concentrations and loads
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
119
89
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
year
C (m
g/L)
0
50000
100000
150000
200000
250000
300000
load
(kg/
yr)
AR mg/LOK mg/LAR loadOK load
0.037 mg/L OK standard
Why would loads be different?
Effects of Lake FrancesEffects of Lake Frances•• The lakeThe lake•• Two streams between sampling stationsTwo streams between sampling stations
Natural variation and errorNatural variation and errorMonitoring program designMonitoring program design
Lake sampling 4 sites, sampled same time4 sites, sampled same time
0.0000
0.0500
0.1000
0.1500
0.2000
0.2500
8/12
/200
3
9/2/
03
9/16
/03
9/31
/03
10/1
4/03
10/2
8/03
11/1
1/03
11/2
5/03
12/1
2/03
12/2
5/03
SRP
(mg/
L)
AR 59 BridgeOK 59 BridgeBallard Creek"little creek"
Soluble Reactive PSoluble Reactive P
Sediment sampling – P flux
A whole A whole lottalotta P flux going onP flux going on•• Anaerobic: ~ 16 (mg/mAnaerobic: ~ 16 (mg/m22)/day)/day
–– 16 is 16 is eutrophiceutrophic, Lake , Lake EuchyEuchy is 4is 4
•• Aerobic: 0.2 Aerobic: 0.2 –– 4 4 –– Very highVery high
A lot of high nutrient sedimentA lot of high nutrient sediment
Variation Sampling and load calculationSampling and load calculation
(USGS 03-4168)
USG
S
AWR
C
15 d
ay u
p 50
15 d
ay Q
onl
y
15 d
ay 9
sto
rm
15 d
ay n
o st
orm
30 d
ay u
p 50
30 d
ay Q
onl
y
30 d
ay 9
sto
rm
30 d
ay n
o st
orm
45 d
ay u
p 50
45 Q
onl
y
45 9
sto
rm
60 d
ay u
p 50
60 d
ay Q
onl
y
60 d
ay 9
sto
rm
Tota
l Pho
spho
rus
Annu
al L
oad
(kg)
100
150
200
250
300
350
400
450
500 Estimator results
60 day15 day 30 day 45 day
For each sampling period, boxes left to right are:•9 storms from upper 50% of flow
•9 storms, upper 50%, no seasonality•9 random storms
•no storms (15 and 30 day)
t hou
sand
95% CI
Variation – flow calculation
400
500
600
700
800
900
1,000
1,100
1,200
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
avg
flow
(cfs
)
AR FlowOK Flow
Monitoring Program Design
Loads for Illinois River agreementLoads for Illinois River agreement•• AR: Monthly sampling; Load = flow*CAR: Monthly sampling; Load = flow*C•• OK: now doing targeted storm sampling OK: now doing targeted storm sampling
(USGS)(USGS)
Also:Also:•• USGS USGS –– ArkansasArkansas•• AWRC AWRC -- autosamplerautosampler
Monitoring program designOklahomaOklahoma
Year Storm sampling
Regression years
coeff. for Q
Load (kg)
Flow-wt C (mg/L)
1998 None 87876 0.138
1999 Start 1997-1999 0.703 130314 0.184
2000 Full 1998-2000 1.09 197346 0.341
2001 Full 1999-2001 1.12 241702 0.417
SummaryLake FrancesLake Frances•• A lot of PhosphorusA lot of Phosphorus--laden sedimentladen sediment•• Not an obvious source or sink of P, Not an obvious source or sink of P,
–– But a source now that point sources are down?But a source now that point sources are down?•• Tributaries not significantTributaries not significantVariationVariation•• Load differences within error/variationLoad differences within error/variation•• Doesn’t explain trendsDoesn’t explain trendsMonitoring Program designMonitoring Program design•• OK is getting more accurateOK is getting more accurate•• OK changes may explain trendOK changes may explain trend
Conclusions (opinion)
Lake can be a longLake can be a long--term source of Pterm source of PDifferences between stations due to:Differences between stations due to:•• Monitoring program differencesMonitoring program differences•• Variation and errorVariation and error
Future - monitoring
New proposed monitoring plan for New proposed monitoring plan for whole Illinois River watershedwhole Illinois River watershed
Future – Lake Frances
Plant something (cattails?)Plant something (cattails?)•• Probably too much troubleProbably too much troubleDredgeDredge•• Good idea, but who pays? Why?Good idea, but who pays? Why?Blow up (rest of dam)Blow up (rest of dam)•• Potential sediment spike worth it?Potential sediment spike worth it?
–– It’s not much of a lake nowIt’s not much of a lake now
Leave it aloneLeave it alone•• likelylikely