Overview of NIBW Site History Overview of NIBW Site History and Current Statusand Current Status

NIBW Site Visit

June 21, 1999

Overview of NIBW Site HistoryOverview of NIBW Site History

Overview of WorkOverview of Work

Comprehensive site characterizationSummary of Site conditions in RI/FSImplementation of ROD-required Remedy

– Capture and containment not achieved

Implementation of Enhanced Remedy– Capture and containment projected

Preparation of FSA– Documentation of effectiveness of Enhanced Remedy

Components of ROD-Required Components of ROD-Required RemedyRemedy

MAU & LAU extraction at wells COS31, COS71, COS72, and COS75

Monitoring of UAU mass fluxSoil vapor extraction at Areas 7, 8,

and 12

Voluntary Components of the Voluntary Components of the Enhanced RemedyEnhanced RemedyCOS6 tie-in to the CGTF (MAU/LAU)Replacement LAU extraction at well

COS75ALAU extraction at well PCX-1MRTF for treatment of groundwater from

PCX-1, and PVWC#15 and #14UAU extraction at Area 7MAU extraction at Areas 7 and 12

Hydrogeology OverviewHydrogeology Overview

SCHEMATIC OF SOUTHWEST MARGIN

HYDROGEOLOGY

UAU

TCE CONCENTRATION

CONTOURS

APRIL 1998

UPPER MAU

TCE CONCENTRATION

CONTOURS

APRIL 1998

LOWER MAU

TCE CONCENTRATION

CONTOURS

APRIL 1998

LAU

TCE CONCENTRATION

CONTOURS

1990

LAU

TCE CONCENTRATION

CONTOURS

1992

LAU

TCE CONCENTRATION

CONTOURS

1994

LAU

TCE CONCENTRATION

CONTOURS

1996

LAU

TCE CONCENTRATION

CONTOURS

APRIL 1998

Area 12 Remedial ActionsArea 12 Remedial Actions

AREA 12

SVE

PROGRAM

ROOSEVELT ROAD

L

MCDOWELL ROAD

HA

YD

EN

RO

AD

GR

AN

ITE

RE

EF

RO

AD

GRANITE

REEF WELL

EXTRACTION

WELL MEX-1MA

TREATMENT

SYSTEM

MAU GROUNDWATER EXTRACTION

AND TREATMENT

PROJECTED

HYDRAULIC

CAPTURE

1,000 gpm

PROJECTED

HYDRAULIC

CAPTURE

1,850 gpm

Performance/Effectiveness Performance/Effectiveness Evaluation for MAU Evaluation for MAU GroundwaterGroundwater

UPPER MAU

WATER LEVEL

CONTOURS

APRIL 1998

YEAR

980

1,010

1,040

1,070

1,100

1,130

1,160

WA

TE

R L

EV

EL

ALT

ITU

DE

(F

EE

T M

SL)

0

200

400

600

800

1,000

1,200

TC

E C

ON

CE

NT

RA

TIO

N (

mic

rogr

ams

per

liter

)

FIG U R E . W ATER LEVEL H YD R O G R APH AN D TC E C O N C EN TR ATIO N FO R M O N ITO R W ELL (A -1-4)1bba1 [M -5M A]

S :/P R O JE C T S/365 /365 .01/JM U R R AY /G R A P H S /M -5M A .G R F /06/18 /99JLM

1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

W L

TCE

YEAR

920

950

980

1,010

1 ,040

1 ,070

1 ,100

WA

TE

R L

EV

EL

ALT

ITU

DE

(F

EE

T M

SL)

0

50

100

150

200

250

300

TC

E C

ON

CE

NT

RA

TIO

N (

mic

rogr

ams

per

liter

)

FIG U R E . W ATER LEVEL H YD R O G R APH AN D TC E C O N C EN TR ATIO N FO R M O N ITO R W ELL (A -1-4)2ccb2 [PG -6M A]

S :/P R O JE C T S/365 /365 .01/JM U R R AY /G R A P H S /P G -6M A .G R F/06 /18 /99JLM

1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

W L

TC E

Performance/Effectiveness Performance/Effectiveness Evaluation for LAU Evaluation for LAU GroundwaterGroundwater

EXTRACTION WELL COS75A

INSTALLATION

ESTIMATED WATER LEVEL ALTITUDE IN VICINITY OF COS75A, APRIL 1995,

PRIOR TO IMPLEMENTATION OF EXTRACTION

ESTIMATED WATER LEVEL ALTITUDE IN VICINITY OF COS75A, APRIL

1997, AFTER IMPLEMENTATION OF EXTRACTION

TCE CONCENTRATIONS AT MONITOR WELL PA-5LA

YEAR

0

50

100

150

200

250

300T

CE

CO

NC

EN

TR

AT

ION

(m

icro

gram

s pe

r lit

er)

FIG U R E . TC E C O NC EN TR ATIO N FO R M O N ITO R W ELL (A -2-4)23ddd4 [PA-5LA ]

PA 5LATC E.G R F/02 /09 /99E AL

1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

EXTRACTION WELL PCX-1

INSTALLATION

ESTIMATED WATER LEVEL ALTITUDE IN VICINITY OF PCX-1, APRIL 1997,

PRIOR TO IMPLEMENTATION OF EXTRACTION

ESTIMATED WATER LEVEL ALTITUDE IN VICINITY OF PCX-1, APRIL 1998,

AFTER IMPLEMENTATION OF EXTRACTION

1996 1997 1998 1999

0.0000

0.0040

0.0080

HY

DR

AU

LIC

GR

AD

IEN

T (

UN

ITLE

SS

)

FIGURE . HYDRAULIC GRADIENT BETWEEN MONITOR W ELLS PA-6LA AND PG-2LA

366.0901\PA-PG 2.G R F\05-06-99

1996 1997 1998 1999

-0 .0080

-0 .0040

0.0000

0.0040

0.0080H

YD

RA

ULI

C G

RA

DIE

NT

(U

NIT

LES

S)

FIGURE . HYDRAULIC GRADIENT BETW EEN MONITOR W ELLS PG-2LA AND PG-41MA/LA

366.0901\PG 2-P G 41.G R F\05-06-99

FSA Groundwater Flow and FSA Groundwater Flow and Contaminant Transport ModelContaminant Transport Model

PurposePurpose

Predictive tool for evaluating a range of remedial actions with respect to:– Capture and containment of the zones of

contamination (flow model) – Relative clean-up time (transport model)

TasksTasks

Compare ROD Required and Enhanced Remedial Alternatives

Simulate range of potential additional Remedial Actions

Simulate combinations of Remedial Actions comprising potential Remedial Alternatives

FSA

MODEL

DOMAIN

AND

BOUNDARIES

(66 sq. mi.)

GENERAL HEAD

BOUNDARY

GENERAL HEAD

BOUNDARY

NO

FL

OW

BO

UN

DA

RY

N

O F

LO

W

BO

UN

DA

RY

Total Mass Removed, Year 2008

0

20000

40000

60000

80000

100000

120000

140000

ROD ENH

Alternative

Pou

nds

of M

ass

Rem

oved

SWMARG-NEW

NEW LAU-3

NEW LAU-2

NEW LAU-1

MILLER/McD

7EXNEW-2

7EXNEW-1

7EX-4MA

7EX-3MA

7EX -1&2

Granite Reef

12M-EX1

PVWC-14

PVWC-15

PCX-1

COS-75A

COS-75

COS-72

COS-71

COS-31

COS-6

Total Mass Removed, Year 2028

0

20000

40000

60000

80000

100000

120000

140000

ROD ENH

Alternative

Pou

nds

of M

ass

Rem

oved

SWMARG-NEW

NEW LAU-3

NEW LAU-2

NEW LAU-1

MILLER/McD

7EXNEW-2

7EXNEW-1

7EX-4MA

7EX-3MA

7EX -1&2

Granite Reef

12M-EX1

PVWC-14

PVWC-15

PCX-1

COS-75A

COS-75

COS-72

COS-71

COS-31

COS-6

EnhancedROD

Estimated TCE Wellhead ConcentrationsCOS 71

0

50

100

150

200

250

300

1990 2000 2010 2020 2030 2040 2050

Year

TC

E C

once

ntra

tion

(ug

/l)

Required Remedy

Enhanced Remedy

Estimated TCE Wellhead ConcentrationsPVWC 15

0

20

40

60

80

100

120

140

1990 2000 2010 2020 2030 2040 2050

Year

TC

E C

once

ntra

tion

(ug

/l)

Required Remedy

Enhanced Remedy