United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R10-90/025
September 1990
EPA Superfund
Record of Decision:
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50272-101
REPORT DOCUMENTATION i. REPORT NO. 2.
PAGE EPA/ROD/R10-90/025
4. TMe and Subtlfle
SUPERFUND RECORD OF DECISION
Fort Lewis Logistics Center, WA
First Remedial Action - Final
7. Auttiof(e)
9. Performing Organization Name and Addreaa
12. Sponeoring Organization Name and Addrea*
U.S. Environmental Protection Aaency
401 M Street, S.W.
Washington, D.C. 20460
3. Reelpienfa Acceeeion No.
5. Report Data
09/25/90
6.
8. Performing Organization Rept No.
10. ProjecVTaek/Work Unit No.
11. Contract(C! or Crant;G) No.
(C)
13. Type of Report & Period Covered
800/000
14.
15. Supplementary Notee
1«. Ab«tr»cl (Limit: 200 wordi)
The 650-acre Fort Lewis Logistics Center site is a military storage and maintenance
facility in Pierce County, Washington. Surrounding land use is mixed residential and
commercial. The site overlies a surficial aquifer, and a deeper bedrock aquifer that
is used as a water supply to over 85,000 people in the area. The Logistics Center is
an industrial complex, which includes warehouses, motor pools, maintenance facilities,
and an equipment disposal yard. From the 1940s to the mid 1970s, solvents including
TCE and PCE were used as degreasers during maintenance activities. The solvents were
frequently combined with waste oil and disposed of at several locations within the
Logistics Center. Site investigations from 1985 to 1988 detected VOC contamination in
onsite monitoring wells and offsite private wells. As a result of these findings,
affected residents were connected to a public water supply. This Record of Decision
(ROD) addresses restoration of the contaminated surficial ground water aquifer, and
provides a final remedy for the site. Confirmation soil sampling and further
characterization of the deep aquifer contamination will be evaluated as part of this
remedial action. The primary contaminants of concern affecting the ground water are
VOCs including DCE, PCE, and TCE.
(See Attached Page)
17. Document Analyeia a. Deacriptore
Record of Decision - Fort Lewis Logistics Center, WA
First Remedial Action - Final
Contaminated Medium: gw
Key Contaminants: VOCs (DCE, PCE, TCE), metals (chromium, lead)
b. Identlflere/Open-Ended Terma
c. COSAT1 Held/Group
18. AvaMaMlty Statement
19. Security C)aea (Thla Report)
None
20. Security Claea (Thie Page)
None
21. No. of Pagea
63 .
22. Price
(Se« ANSI-Z39.1S)
Sw Inatfuctiont on finvnw
\Jr IIUNAL r\JnM iff \
(Formerly NTIS-35)
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,I
EPA/ROD/R10-90/025
Fort Lewis Logistics Center, WA
First Remedial Action - Final
Abstract (Continued)
The selected remedial action for this site includes pumping and onsite treatment of
ground water using air stripping to remove VOCs; discharging the treated water onsite
to infiltration trenches, including one trench located upgradient to facilitate
flushing of secondary contaminant sources; long-term monitoring of ground water;
conducting confirmation soil sampling; investigating the deep aquifer contamination for
possible remediation; and implementing institutional controls. The estimated present
worth cost for this remedial action is $9,068,000, which includes an annual O&M cost
(exclusive of maintenance) of $517,000 for 30 years.
PERFORMANCE STANDARDS OR GOALS: Ground water cleanup standards are based on Federal
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I.
II.
III.
IV.
V.
VI.
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VIII.
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XI.
.
RECORD OF DECISION
for the
DEPARTMENT OF THE ARMY
LOGISTICS CENTER
FORT LEWIS. WASHINGTON
TABLE OF CONTENTS
Declaration of the Record of Decision
Decision Summary
Introduction
Site Name. Location, and Description
Site History and Enforcement Activities
Community Relations
Scope and Role of Response Action Within Site Strategy
Documentation of SignifICant Changes
Summary of Site Characteristics
Summary of Site Risks
Description of AJtematives
Summary of COmparative Analysis of Alternatives
The Selected Remedy
The Statutory Detenninations
Page
,
1
3
4
5
6
6
16
24
27
30
34
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DEClARATION OF THE
RECORD OF DECISION
SITE NAME AND LOCATION
Logistics Center
Fort Lewis. Pierce County, Washington
STATEMENT OF BASIS AND PURPOSE
This decision doQJment presents the selected remedial action for the Logistics Center operable unit. at
Fort Lewis. Washington, which was chosen in accordance with the Comprehensive Environmental
Response. Corf1)ensation, and Liability Act of 1980, as amended by the Superfund Amendments and
Reauthorization Act of 1986, and to the extent practicable, the National Oil and Hazardous Substances
Pollution Contingency Plan. This decision is based on the administrative record for the Logistics Center
operable unit.
The State of Washington concurs with the selected remedy.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this site. if not addressed by implementing
the response action selected in this Record of Decision, may present an imminent and substantial
endanger~ent to public health. welfare. or the environment.
DESCRIPTION OF THE SELECTED REMEDY
The selected remedy for the Logistics Center operable unit addresses the principal threats posed by
the site by treating the groundwater and by flushing secondary source residual contamination. The
remedy is designed to reduce exposure to the contaminated groundwater and to remediate the
groundwater to levels that are protective of human health and the environment.
The major components 01 the selected remedy include:
- Install groundwater extraction wells capable of capturing the groundwater contaminant plume in the
unconfined aquifer.
- Install on-site groundwater treatment facilities to remove contaminants from the collected groundwater.
- To expedite groundwater remediation. install groundwater extraction wells near areas of highest
concentration of contamination and discharge treated groundwater upgradient of these extraction wells
to facilitate flushing secondary sources from the groundwater.
- Monitor the groundwater contaminant plume and the extractionltreatment system during groundwater
remediation activities to ensure that both groundwater and surface water remediation goals are achieved.
- Implement administrative and institutional controls tha1 supplement engineering controls and minimize
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e
- Investigate the Iowef' aqulfer(l) to detemine the presence of contamination and to evaluate the extent
of contamination. If neoesaary. "contamination Is found, a groundwater extraction system will be
installed which is capabte of capeunng the contaminant plume with subsequent treatment of the extraCted
groundwater in the on-sIe trestmefC facility. The remediation goals specified for the unconfined aquifer
will also apply to any contaminated loWer aquifers.
- Perform confirmation ~U ~ to ensure that all remaining sources of soil contamination have
been identified and chatadertzed.
DECLARAll0N
. The selected remedy Is protective of ~man health and the environment, co~\ies with Federal and
State requirements that are legally applicable or relevant and appropriate to the remedial actiOn, and
is cost effective. This remedy uses permanent solutions and alternative treatment technology to the
maximum ex1ent practicable, and satisfies the statutory preference for remedies that e~y treatment
that reduces toxicity, mobility, or volume as a principal element.
Because this remedy will result In hazardous substances remaining on-site in the groundwater above
health-based levels for longer than five years, a review will be performed within five years after the
commencement of remeOl3l action to ensure that the remedy contiooes to provide adequate protection
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SIgl1C1(ure 6110el for (he: loregolilljJ Fort Lewis loglsllcs Center" neeord 01 Oeclslon bet.veen lite
Dopartrnel1l 01 the Army and U.S. Environmental Protection Agency. wIth concurrence by lilt WashlngtQn
State Department 01 Ecology.
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Signature sheet lor the loregoing Fort Lewis Logistics Center Record of Decision between the
Department 01 the Army and the U,S. Environmental Protection Agency, with concurrence by the
Washington State Department 01 Ecology,
Q-ZS-90
Date
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Signature sheet for the foregoing Fort Lewis Logistics Center Record of Decision between the
Department of the Army and the U.S. Environmental Protection Agency, with concurrence by the State
of Washington Department of Ecology.
~~
(=:oC't..CHRISTINE GREGOIRE
Director, State of WashIngton Department of Ecology
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Date
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KE ElH . EIKENBERRY
Attorney General
State of Washington .
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DEOS8ON SUMMARY
INTRODUCTION
The Fort Lewis Logistics Center was listed on the National Priorities List (NPL) in December 1989,
under the Comprehensive Environmental Response. ~nsation. and Uability Ad of 1980 (CERCLA
or Superfund) as amended by the Superfund Amendments and Reauthorization Ad of 1986 (SARA).
An installation-wide Federal Facilities Agreement (Agreement), Administrative Docket Nos. 1088-06-16-
120 and 1089-09-23-120, between the United States Army (Army), the United States Environmental
Protedion Agency (EPA), and the State of Washington Department of Ecology (Ecology) became
effective January 29, 1990. The Agreement establishes a proceOOral framework for agency coordination
and a schedule for all CERCLA activities conducted at Fort Lewis.
Pursuant to Executive Order 12580 (Superfund In1>Iementation) and the National Oil and Hazardous
Substances Pollution Contingency Plan (NCP), the Army performed a Remedial Investigation/Feasibility
Study (RVFS) for the Logistics Center. The Remedial Investigation (RI)(1988) charadertzed
contamination in the groundwater. soil. surface water. and sediments. The Baseline Risk Assessment
(1989) evaluated potential effects of the contamination on ooman health and the environment. The
Feasibility Study (FS)(1990) evaluated altematives for remediating contamination. In accordance with
section 120(e)(2) of CERCLA, the Army will begin the remedial action within 15 months of con'4>letion
of the RVFS process. .
I. SITE NAME, LOCATION, AND DESCRIPTION (Figure 1)
The Fort Lewis Logistics Center Is located in Pierce County. Washington. approximately 11 miles south -
southeast of Tacoma and approximately 17 miles east - northeast of OIyfT1)ia (Figure 1). The Logistics
Center occupies approximately 650 acres of the Fort Lewis military reservation. located in T 19 N, R
2 E, Sections 21, 22. 26, and 27. It is bounded to the northwest by Interstate 5. to the southwest by
the Fort Lewis Madigan Army Medical Center, to the north by the American Lake Gardens Tract, and
to the east by ouUying areas of the Fort Lewis Installation.
The Logistics Center is an Industrial COfT1)lex comprised of warehouses. motor pools, maintenance
facilities. and an equipment dispOSal yard. The following four potential source areas were investigated
as part of the RI:
- East Gate Disposal Yard (includes Landfill No.2);
- Defense Reutilization and Marketing Office (DRMO) Yard (previously known as DPDO Yard):
- North Uses Area (includes Landfill No.6. Industrial Wastewater Treatment Plant [IWTP], and Battery
Acid Pit): and
- Well LC-6 and Pit Area.
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Cross-~
,\ shown In Figure 2
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Approximately 85.000 residents reside within a three-mile radius of the logistics Center in the
surrounding communities of Fort Lewis, TUllcum, American Lake Gardens Tract. Lakewood, and McChord
Air Force Base. TilliaJm is a mixed residential and oomrnerdal area wIhout a major Industry. The
commercial use consists mainly of restaurants. gas stations, and convenience stores. The American
Lake Gardens Tract is predominantly a residential area. Lakewood is a mixed residential and
commercial area.
Drinking water for TilliaJm and American Lake Gardens Tract is supplied by the Lakewood Water
District. The nearest Lakewood Water District well is located within one mile northwest of the Logistics
Center and draws water from a depth of approximately 480 feet from within the PuyalkJp Formation
aquifer. Fort Lewis receives its drinking water primarily from Sequalitchew Springs, whid1 is located
within one mile southwest of the Logistics Center and adjacent to $equalitchew Lake. Two emergency
backup drinking water wells (Wells 13 and 16) are located within one mile of the Logistics Center. Each
well draws water from several aquifers located beneath the contaminated unconfined a~ifer. A third
drinking water well (Well 7). which Is not used, Is scheduled for abandoM18nt in accordance with the
Minimum Standards for Construction and Maintenance of Wells (Chapter 173-160 WAC).
The nearest surface water bodies are American Lake, Lynn Lake. Mondress Lake. and Murray Creek,
all of which are located within one mile of the Logistics Center. The Logistics Center is located within
five miles of the Puget Sound.
II. SITE HISTORY AND ENFORCEMENT ACTIVITIES
The Logistics Center. formerly called the Mount Rainier Ordnance Depot. was built in the earty 19405.
The LogisticS Center is used for storing supplies and providing maintenance of military equipment and
vehicles. The primary contaminant, trichloroethylene (TCE). is a common industrial and commercial
solvent and degreaser. and was used for maintenance activities until the mid-1970s. The waste TCE.
which was often combined with waste oil. was disposed of at several areas within the Logistics Center.
In 1985. th~ Army identified traces of TCE in several monitoring wells installed in the UncorllOed aquifer
beneath the Logistics Center. A limited site investigation was performed in 1986 under the Department
of Defense Installation Restoration Program (IRP). During 1986 and 1987, the EPA performed a
groundwater investigation in and near Ttllicum and found that groundwater contamination in Tillicum
appeared to originate from the Logistics Center. As a result. the Army agreed to study the groundwater
plume off the installation as part 01 the logistics Center RI. The Army began the RI in 1987. which
included a field investigation to detennine contamination in soil. groundwater. surface water, and
sediments. In 1988, the RI was modified to include study of the horizontal extent of the off-post
groundwater plume.
Drinking water for most residents in the Tillia.im area is supplied by the Lakewood Water District.
However. during the AI, the Army identified several residents using private drinking water wells. The
Army subsequently sampled these wells and connected residents with contaminated wells to the
Lakewood Water District.
A. Source Areas
During the 1986 IRP site investigation, four potential areas of contamination were identified within the
Logistics Center where maintenance and disposal activities reportedly occurred. Minimal historical
infonnation for each potential source area exists. These potential source areas were investigated as
part of the RI. They were defined as the East Gate Disposal Yard. the DRMO Yard, the North Uses
Area. and Well LC-6 and Pit Area (Figure 1).
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1. East Ga1e DispOsal Yard
The East Gate Disposal Yard was used between 1946 and 1960 as a disposal site for waste generated
by the Mount Aainier Ordnance Depot. Interpreta1ion of aerial photographs indicated several trenches
were excava1ed in the yard. The trenches reportedly were used for the disposal of waste TCE and
petroleum, oils, and lubricants (POl) from equipment cleaning and degreasing activities. The trenches
were subsequently backfilled and are not currently visible.
2. North Uses Area
The North Uses Area consists of Landfill No.6, the Industrial Wastewater Treatment Plant (IWTP). and
the Battery Acid Pit.
The IWTP began operating in 1954. The facility predominantly receives storm water runoff from nearby
maintenance facilities. Effluent from the IWTP is discharged to a no-outlet evaporation/percolation
lagoon. Sludges and sediments from the lagoon are currently dispoSed of in the on-post municipal
landfill, whid1 is not located at the Logistics Center. From 1954 to the mid-1970s, sediment and
sludges from the IWTP's evaporationlpercola1ion lagoon were disposed of in Landfill No.6.
From 1971 to 1976, electrolyte solutions from batteries were disd1arged into the Battery Acid Pit, which
contained crushed limestone. While it is not known how many varieties of batteries were drained at
the Battery Acid Pit, it is known that the majority were vehicle batteries containing lead-acid electrolyte.
3. Well LC-6 and Pit Area
The Well LC~ and Pit Area is CO"1)rised of an abandoned POL pit in the vicinity of Well LC-6. The
pit area consisted of a storage/disposal pit which reportedly contained a storage tank. However,
subsequent investigations revealed no evidence of a storage tank in this area. The pit appears on
aerial photographs da1ed 1951, and may have been a disposal site for waste oil and solvent from
nearby vehicle storage areas.
4. DAMO Yard
The DAMO Yard is used currently as a general use te~rary storage area. Stored materials include
equipment containing residual polychlorinated biphenYls (PCBs). In the past, unknown quantities of
stored materials included drums containing waste TCE and equipment containing PCBs.
III. COMMUNITY RELATIONS
The public was first notified of the Logistics Center groundwater contamination in January 1985. At that
time, the Army announced that it had discovered TCE in new monitoring wells installed at the Logistics
Center. This announcement was published in several area newspapers.
A. Community Relations durtng the RIIFS
In August 1986, following completion of the limited site investigation, several newspapers published
articles announdng the results of the investigation. It was reported that TCE-<:ontamina1ed groundwater
originating from the Logistics Center was a potential threat to the Lakewood Water District well located
in Tillicum.
In 1987, a community relations plan (CAP) was prepared in accordance with CERCLA, as amended by
SARA The CAP included establishing infonTIa1ion repositories and communication pathways to
disseminate information. Infoonation repositories were established at the following four locations:
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Pierce County linary - Lakewood Branch:
Pierce County Linary - TlUlcum Branch:
Tacoma Pierce County Health Department: and
Fort Lewis - Environmental Division.
Also, in accordance with section 11301 CERCLA, an administrative record was established to provide
the basis for selection of the remedial action. The administrative record is available for public review
at the Fort Lewis Environmental Division and the Lakewood Branch of the Pierce County Lb'ary.
During the RifFS, the Arrrr'f issued three fact sheets and three press releases. In March 1987, the first
fact sheet announced the beginning of the RVFS. The second fact sheet was released in February
1988 when the RifFS was modified to indude TlIliQJm. A third fact sheet, released in February 1989,
discussed the risk assessment. After releasing the second and third fact sheets. the Army held public
workshops to present information and to answer questions. Both workshops were held at the
TillicumlAmerican Lake Gardens Community Service Center and coincided with regular monthly public
meetings held at the Center. Between 20 to 40 people attended each workshop.
In January 1990, two newspaper articles were published. The first article announced the listing of the
Logistics Center to the NPL. The second article announced the signing of the Federal Facilities
Agreement.
B. Community Relations to support selection of remedy
In accordance with sections 117 and 113(k)(2)(B) of CERCLA. the public was given the opportunity to
participate in the remedy selection process. The proposed plan. which summarized the alternatives
evaluated and presented the preferred alternative, was mailed to approximately 250 interested parties
in June 1990. The Arrrrf provided public notice through a display ad in the Tacoma News Trtxme and
the Lakewood Journal to explain the proposed plan, list the public comment period, and announce the
public meeting. A news release was also provided to the local news media which resulted in news
coverage by four local newspapers and twO radio stations.
A 45-day public comment period was held from June 5 to July 19. 1990. No requests for extensions
and no written comments were received during the comment period. Approximately 30 people attended
an open hOuseJpublic meeting, which was held on June 28, 1990 in Tillicum. Responses to comments
received at the public meeting are included in the attached Responsiveness Summary.
A fact sheet summarizing the Record of Decision (ROO), public comments. and the Army's response
will be mailed to interested parties on the mailing Ust atter the ROD is signed. Copies of the ROD and
the Responsiveness Summary will be placed in the administrative record and in the information
repositories.
IV. SCOPE ANt) ROLE OF RESPONSE AcnON WITHIN SITE STRATEGY
The selected remedy for final action is intended to address all the concerns originating from the
contamination at the Logistics Center. induding the principal threat of volatile organic colT1>OUnd (VOC)
contamination in the unconfined aquifer.
The primary purpose of the selected remedy is to restore the unconfined aquifer to Class I. or drinking
water, status. In addition, the selected remedy establishes cleanup standards for the remediation of all
aquifers exhibiting contamination from the Logistics Center. The Army will perform additional field work
in Fall 1990 to determine and characterize contamination in the lower aquifers. If contamination
originating from the Logistics Center is found. remediation (cleanup) goals specified herein will apply
to the affected aquifer(s).
During the RI, contamination was discovered in private drinking water wells that draw water from the
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unconfined aquifer. The Immediate threat to human health was eliminated when the Army connected
weD owners to the Lakewood Water District. However, the private drinking water weBs were not
abandoned. No administrative or Institutional mechanism is available that requires the abandonment
of private residential wells due to chemical contamination. Through community relation activities, the
Amrt continues to notify the residents that the wells should not be used for drinking water. The
selected remedy inctudes the use of administrative controls to regulate construction of new wells within
the contaminated unconfined aquifer and to discourage use of existing contaminated wells.
To aid in the design of the on-site treatment system, interim groundwater and surface water sampling
will continue until the treatment facility is constructed. Once treatment begins, a Iong-tenn monitoring
program will be if11)lemented to evaluate performance of the extractionltreatment system and compliance
with remediation goals.
Potential source areas within the Logistics Center were sampled during the AVFS to determine if soil
contamination was a threat to public health and the environment. While analytical results indicate that
the soil does not pose a direct threat to human health, it may act as a source of contamination to the
groundwater. The effICacy of the groundwater remediation will be monitored quarterly during remedial
action. In the event that residual contamination in the soil adversely impacts the ability to remediate
groundwater, the need for soil treatment will be reevaluated.
So~ sampling results from the AI indicate that no sources of soil contamination at the Logistics Center
present an unacceptable risk to human health or the environment. However, subsequent field screening
at the DAMO yard found previously unidentified areas of potential PCB soil contamination. As part of
the selected remedy, the Army will conduct confirmation soil sampling in all four potential source areas,
incllding the DAMO yard, to ensure that all soil contamination within the Logistics Center has been
identified and characterized. Based on the results of the confirmation sampling, a prompt determination
will be made, pursuant to the procedures outlined in the Federal Facility Agreement, reganftng the n.eed
for a response action. The Army will notify the public of the results from the confirmation soil sa~ling.
Any necessary response action will be undertaken by the Army, in consultation with EPA and Ecology,
pursuant to the NCP Part 300.
V. DOCUMENTA110N OF SIGNIFICANT CHANGES
--
The proposed plan originally discussed a waste management area to address a potential risk associated
with residual soil contamination within the Logistics Center. However, based on acceptable exposure
levels outlined in the final NCP, the residual soil contamination levels are within the acceptable exposure
levels that represent an excess upper bound lifetime cancer risk to an individual of between 10. and
10". Therefore, there is no waste management area and the remediation goals will be attained
throughout the contaminated plume.
VI. SUMMARY OF sITe CHARACTERISTICS
Analyses of the soil, groundwater, surface water, and sediments indicate that groundwater contamination
is the principal threat at the Logistics Center site. The primary contaminants found in the groundwater
are trichloroethylene (TCE) and cis 1,2 . dichloroethylene (DCE).
Solvents that include TCE, tetrachloroethylene (PCE), and 1,1,1 - trichloroethane (TCA) were used
for maintenance activities at the Logistics Center. TCE was used until the mid-1970s. AIl accurate
estimate of the amount of TCE disposed of cannot be made because there is minimal recorded disposal
information before the 1970s. The source of DeE contamination is not known, as DCE was not used
at the Logistics Center. DCE was possibly an impurity of the TCE solvent and/or is the degradation
product of TCE.
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The potentially exposed populations Indude the residents of Tillia..m and the American Lake Gardens
Tract that still have functioning contaminated private wells. These residents are now connected to an
alemate water supply, but the wells have not been abandoned. In addition, potential exposure may
OCQJr if new private wells were to be installed into the unconfined aquifer. If the contamination migrates
to the deeper aquifers, it could potentially affect the water supply for approximately 85,000 people in
the surrounding comrnmities of Fort Lewis, Lakewood, Tillia..m, and American Lake Gardens Tract.
The following discussion .summarizes data from the sampling and analyses pertormed as part of the RI.
A. Groundwater Contamination
The Logistics Center is on an extensive upland glacial drift plain which OCOJpies much of central Pierce
County (Figure 2, Table 1). The geologic investigations demonstrate that the hydrostratigraphy of the
. area is extremely diverse and complex. There are numerous different geologic units in the 300 feet
beneath the Logistics Center. These units vary both horizontally and vertically making hydrological
interpretation very difficult. Generally, the geology beneath the Logistics Center consists of sand and
gravel deposits with till layers (Vashon Drift) overtying a finer - grained, nonglacial deposit (Kitsap
Formation). The Vashon Drift is mostly permeable and contains the unconfined aquifer beneath the site.
The base of the aquifer is the Kitsap formation, which separates the unconfined aquifer from the Salmon
Springs aquifer, which is between 100 to 200 feet below the surtace. In addition, the Salmon Springs
over1ies the PuyaJlup Formation, which is between 250 to 450 feet below the surface. The unconfined
aquifer is continuous across the site; the water table is between 7 to 35 feet below the surface.
Groundwater beneath the Logistics Center is recharged by groundwater inflow from the southeast, and
from infiltration of precipitation through the permeable soils. The water table gradient (slope) is to the
north - northwest across the Logistics Center and is approximately 10 feet per mile. Groundwater
velOCities range from 0.03 to 26 feet per day, with a median velocity of 1.5 feet per day. Aquifer
transmissivity ranges from 14,000 to 20,000 gallons per day per foot.
During the RI, 96 pre-existing wells and 33 new wells were Sa"1>led for TCE and DCE. Six wells were
sampled for Hazardous Substance list (HSL) co"1>Ounds. Five of the new' wells were installed at
depths of 150, 200, 300 feet in the lower aquifers (the aquifers below the unconfined aquifer). Table
2 summarizes the groundwater sampling results from the RI and lists available MCUMCLGs for
contaminants found.
VOC contamination has been found in the groundwater beneath and northwest (downgradient) of the
Logistics Center. The VOCs detected in the groundwater were TCE, DCE, PCE, and TCA. TCE and
DCE exceeded EPA's MaxirT1Jm Contaminant Levels (MCLs) for drinking water. Vinyt chloride, a
degradation product of TCE. was not detected in the wells sampled. PCE was detected slightly above
its MCL of 5 ugI1 (miaograms per liter) in one sample for one sampling event. TCA was detected
below its MCL of 200 ugll. TCE ranged in concentrations from less than 0.1 ugll to 2400 ugl1, with an
average concentration of 325 ugII. DeE ranged in concentrations from less than 0.15 ugll to 130 ugll,
with an average concentration of 24 ugII. The highest contamination levels in the unconfined aquifer
appear to be between 16 to 37 feet below the ground surface.
In the Salmon Spcings aquifer, six wells (F8Qure 3: T-9, T-ge: LC-41 d,e: LC-55 d,e) were sampled for
contamination. One wett (Lc-41d at a 200 foot depth) showed a maximum TCE level of 143 ugll. No
contamination was found in the other five wells.
In general, the contaminant ptume (the area of groundwater contamination) in the unconfined aquifer
migrates from the southeast to the northwest, from the East Gate Disposal Yard, under the Logistics
Center, Tillicum and the southwest comer of the American Lake Gardens Tract. Figure 3 shows the
horizontal ex1ent of the groundwater plume in the unconfined Vashon Drift aquifer. The vertical cross
section of TCE contamination in the unconfined aquifer (defined by the 5 ugll TCE concentration limit)
is fairty constant along the path of the groundwater plume. The contaminated plume is between 3,000
to 4,000 feet wide with a contaminated thickness of between 60 to 80 feet.
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Table 1 Description of Geologic Units
\.0
GEOLOGICI SITE ' Approximate Approximate SITE
STRATIGRAPHIC GEOLOGIC DESCRIPTION Depth to Top 01 Thickness, FI. HYDROGEOLOGIC
UNIT NAME Unit, FI. DESIGNATION
Recent Recent Deposits rd Predominantly alluvial silt, sand, and 0, locally 0-10 aquifer where saturated
gravel with lesser amounts 01 organic present
deoression lillinas .
Vashon & Stade- Steilacoom Gravel Ovs Open-work coarse gravel with abundant 0-10 20-40 Vashon DriIVpost-Kitsap
Fraser Glaciation cobbles Aquiler
Vashon Till Ovt Very dense lodgement till: gravelly, clayey 3-50, locally 2-20 (Qvt-aquitard)
sandy silt; and loose ablation till: gravelly, absent
clavev, sandy sill.
Vashon & pre- Glacial Outwash Sand Gs Predominantly stratilied line, medium, and 5-125 locally 2-100
Vashon outwash course sand; interbeds 01 sandy gravel inter bedded
lenses 01 sik
Glacial outwash Gravel Gg Predonimamtly sandy gravel with lenses 5-130 locally 2-100
01 gravelly sand and silty gravel inter bedded
pre-Vashon & . Undifferentiated Till tu Lodgement till, glaciomarine drill (?), 30-90, locally 2-35 (tu-aquitard)
post-Kitsap glaciolacustrine deposits, and lesser absent
amounts 01 ablation till: predominantly ve~
dense to hard, sandy silt and clayey sik
Noni}lacial Deposits n9 Alluvial sand and gravel: and mudflow 70-140, 10-40 (ng-aquitard, in places
deposits; gravel and sand in a matrix 01 locally absent
clav and silt
Olympia Interglacial Kitsap Formation Ok Noni}lacial deposits 01 sik, sand, and clay 1 to-t70 10-70 Kitsap Aquitard
with scattored ash, wood and poot
Salmon Springs Salmon Springs Ossr Stratified sand and gravel with silt and 135-225, 20-60 Salmon Springs
Glaciation Recessional Outwash clay lenses locally absent Recessional Aquifer
Salmon Springs Till Osst Very dense, heterogeneous mixturo of 150-280 5-20 Salmon Springs Till
gravel, sand, clay, and silt Aquitard
Salmon Springs Ossa Stratilied sand and gravel with silt and 230-300, 10-80 Salmon Springs
Advance Outwash clav lenses locally absent Advance Aauifer
Puyallup Interglacial Puyallup Formation Opy Mudflows, ash, and alluvial deposits 210-320 up to 135 Puyallup Aquitard
Stuel. ~Iacial . Stuck Drill Ost Till, lacustrine silt and fine sand. >320 50-100 Stuck Drih Aquiler
glaciofluvial sand and gravel' .;.
-------
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FIGURE 2
I'RELIMINARY HYDl-l0GEOLOGIC
PROFILE
Note: Reier 10 Figure 1 lor cross-section location.
8
.~~- ------~-------~
-------
TABLE 2A
....
o
I
....
InorganiclI Upgnldient Downgradient
Parameter Range of 1/ Prequency 21 Rango of Moan of Rango of
Concentration of Dotection Concentration Concentration DLa 3/ MCL 4/
-------
tJ
TABLE2B
Fort Lewis Logistics Center
Groundwater Sampling Results
Total (unfiltered)
Volatiles . Frequency 1/ Rangc of Mean of Range of MCL}/ '.
Pa:rameter of Detection Caocentraticm Cooceutration DLs 2J
(ugI1) (ugIl) (ugfl) (ngJ1)
Chloromethane 0/6 - - 10-50
Bromomethane 0/6 - - 10-50
Vinyl Chloride 0/6 - - 10-50
Chloroethane 0/6 - - 10-50
Methylene Chloride 0/2 - - 25-50
Ac~ne 0/4 - - 10-100
Carbon Disulfide 0/6 - - 5-25
1,l-Dichloroethylene «(DCE) 0/6 - - 5-25
1,1- Dichloroethane (DCA) 0/6 - - 5-25
1,2-Dichloroethylene (DCE) 298/502 0.1-130 24 0.10-1.2 70p 31
Chloroform 0/6 - - 5-25
1,2-Dichloroethane (DCA) 0/6 - - 5-25
2-Butanone 0/6 - - 10-50
1,I,I-Trichloroethane (TCA) 1/6 I I 5 100
Carbon Tetrachloride 0/6 - - 5-25
Vinyl Acetate 0/6 - - 10-50
Bromodichloromethane 0/6 - - 5-25
1,2- Dichloropropane 0/6 - - 5-25
cis-I ,3-Dichloropropene 0/6 - - 5-25
Trichloroethylene (TCE) 401/503 0.1-2400 325 0.1 -0. 15 5
Dibromochloromethane 0/6 - - 5-25
1,1,2- Trichloroethane 0/6 - - 5-25
Benzene 0/6 - - 5-25
Trans-l,3-Dichloropropene 0/6 - - 5-25
Bromoform 0/6 - - 5-25
4- Methyl- 2 - Pentanonc 0/6 - - 10-50
2-Hexanone 0/6 - - 10-50
Tctrachloroethylene (PCE) 1/6 6 6 5-25 5p 3/
Toluene 0/6 - - 5-25
1,1,2,2- Tetrachloroethane 0/6 - - 5-25
Chlorobenzene 0/6 - - 5-25
Ethylbenzene 0/6 - - 5-25
Styrcnc 0/6 - - 5-25
Xylcocs Total 0/6 - - 5-25
2-chloroethyl vinyl ether 0/6 - - 10-50
-
1/ Frequency of Detectioa=Dumber of detectiOlJs/aumber of samples IUJJIlyzed
21 Range of DLs=range of detection limits
J/ MCL=maximum coataminant level
-------
TABLE 2C
Fort Lewis Logistics Center
Groundwater Sampling Results
Total (unfiltered)
SemivoLa tiles Frequency 1/ Range of Mean of Range of
Parameter of DctcctiOD. Concentration Cooc=tration D Ls '}J
(ugll) (ugll) (ugll)
Phenol 0/6 - - 10
bis(2 -Chloroetby I)E tber 0/6 - - 10
2 -Chlorophenol 0/6 - - 10
1,3-Dichlorobenzene 0/6 - - 10
1,4-Dichlorobenzene 0/6 - - 10
Benzyl Alcohol 0/6 - - 10
1,2-Dichlorobenzene 0/6 - - 10
2-Metbylphenol 0/6 - - 10
bis(2 -Choloroisopropyl) Ether 0/6 - - 10
4- MethylpheDol 0/6 - - 10
N -Niuoso-Di -D- Dipropyla mine 0/6 - - 10
Hexachloroetbane 0/6 - - 10 I
NiuobenzeDe 0/6 - - 10
lsophorone 0/6 - - 10
2-NiuoPgeDOI 0/6 - - 10
2,4-DimetbylpheDol 0/6 - - 50
Benzoic Acid 0/6 - - 10
bis(2 -Chloroe thoxy)M ethane 0/6 - - 10
2,4-DichloropheDol 0/6 - - 10
1,2,4- TrichlorobenzeDc 0/6 - - 10
Naphthalene 0/6 - - 10
4-Chloroan.iline 0/6 - - 10
Heuchlorobutadiene 0/6 - - 10
4-Chloro- 3-MethylpheDol 0/6 - - 10
2-Methylnaphthalene 0/6 - - 10
Heuchloroc)'c lopen tadiene 0/6 - - 10
2,4,6- Trichlorophenol 0/6 - - 10
2,4,5- Trichlorophenol 0/6 - - 50
2 -Chloronaphtbalene 0/6 - - 10
2-Nilroslliline 0/6 - - 50
11 Frequellcy of Detectioll=tJumber of del.CCtiOlJS/llumber of samples MJIIlyzcd
21 Rallge of DLs=rsDge of deuxtioll limits
-------
>l
TABLE2C
(continued)
Fort Lewis Logistics Center
Groundwater Sampling Results
Total (unfiltered)
Semivo!.atiles Frequency 11 Range of Mean of Range of
Parameter of Detection Conceotration Conceotration DLs 21
(ugl1) (ugl1) (ugl1)
Dimethyl Phthalate 0/6 - - 10
Acenaphthylene 0/6 - - 10
2,6-Dinitrotoluene 0/6 - - 10
3-Nitroaniline 0/6 - - 50
Acenaphthene 0/6 - - 10
2,4-Dinitrophenol 0/6 - - 50
4-Nitrophenol 0/6 - - 50
Dibenzofuran 0/6 - - 10
2,4-Dinitrotoluene 0/6 - - 10
Diethylphthalate 0/6 - - 10
4-Chlorophenyl-phenyl Ether 0/6 - - 10
I Fluorene 0/6 - - 10
4 - Ni troaniline 0/6 - - 50
4,6- Dinitro- 2 - Methylphenol 0/6 - - 50
N -Nitrosodiphenylamine 0/6 - - 10
4- Bromophenyl-phenylether 0/6 - - 10
Hexachlorobenzene 0/6 - - 10
Pentachlorophenol 0/6 - - 50
Phenanthrene 0/6 - - 10
Anthracene 0/6 - - 10
Di -n - Butylphthalate 0/6 - - 10
Fluoranthene 0/6 - - 10
Pyrene 0/6 - - 10
Butylbenzylphthalate 0/6 - - 10
3,3' - DicbIorobenzidine 0/6 ,- - 20
Benzo(a)Anthracene 0/6 - - 10
Chrysene 0/6 - - 10
bis(2 - E thylhexyl)Phthalate 0/6 - - 10
Di-n-OCtyl Phthalate 0/6 - - 10
Benzo(b )Fluoranthene 0/6 - - 10
Benzo(k)Fluoranthene 0/6 - - 10
Benzo(a)Pyrene 0/6 - - 10
Indeno( 1 ,2,3-cd)Pyrene 0/6 - - 10
Dibenz(a,h)Anthracene 0/6 - - 10
Benzo(g,b,i)Peryleae 0/6 - - 10
1/ Freq~cy of DetectiOll=number of detectiolJS/lJumber of samples IUJsJyzed
-------
TABLE2D
Fort Lewis Logistics Center
Groundwater Sampling Results
Total (unfiltered)
Pc&ticidcslPCBs F requeocy 11 Range of Mean of lUnge of
Parameter of Detection Concentration Coacentratioa DLs 21
(uglI) (uglI) (uglI)
alpha-BHC 0/6 - - 0.01-0.05
beta-SHC 0/6 - - 0.01-0.05
delta-SHC 0/6 - - 0.01-0.05
gamma-SHC(Lindane) 0/6 - - 0.01-0.05
Heptachlor 0/6 - - 0.01-0.05
Aldrin 0/6 - - 0.01-0.05
Heptachlor epox.ide 0/6 - - 0.01-0.05
EndosuIfan I 0/6 - - 0.01-0.05
Dieldrin 0/6 - - 0.02-0.10
4,4'-DDE 0/6 - - 0.02-0.10
Endrin 0/6 - - 0.02-0.10
Endosulfan II 0/6 - - 0.02-0.10
4,4'-DDD 0/6 - - 0.02-0.10
Endosulfap sulfate 0/6 - - 0.02-0.)(\
4,4'-DDT 0/6 - - 0.02-0.10
Methoxychlor 0/6 - - 0.10-0.50
Endrin ketone 0/6 - - 0.02-0.10
Chlordane 0/6 - - 0.10-0.50
Toxaphene 0/6 - - 0.20-1.0
Aroclor-l016 0/6 - - 0.10-0.50
Aroclor-1221 0/6 - - 0.10-0.50
Aroclor-I232 0/6 - - 0.10-0.50
Aroclor-1242 0/4 - - 0.10-0.50
Aroclor-1248 0/6 - - 0.10-0.50
Aroclor-I2S4 0/6 - - 0.2-1.0
Aroclor-1260 0/6 - - 0.2-1.0
1/ Frequency of Det/:{;tion=tlUI1Jber of detections/number of samples alUlyzed
2/ Range of DLs=range of det/:{;cioD limits
-------
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S LOGISTICS CENTER
REMEDI~~~~.;:~IIGATION I FEASIBILITY STUDY
FIGURE 3
HORIZONTAL EXTENT OF
TCE CONTAMINATION IN THE
UNCONIFINED AQUIF~R
-------
Based on groundwater contours, TCE contamination from groundwater appears to discharge Into
Ameftcan Lake at IeYets slghUy above 5 ugII. Subsequent sa"1>ing found that TCE and DCE levels
were not elevated In the surface water or sediments of American Lake. Results from the surlace water
sa"1'ing are disaJssed below.
B. Surface Water and Sediment Contamination
Surface waters and sediments that could be affected by contamination from the Logistics Center were
~. Surface water and secrll1'18nt samp6es were collected from American Lake, Lynn Lake, Murray
Creek, and Lake Mondress. Based on groundwater sa"1>ling results, surface water and bottom
sediment safT1)les were tested for TCE and DeE. Table 3 summarizes the results of surface water and
sediment sampling and co~res levels found with federal Arrbient Water Quality Criteria (AWQC).
. Although, levels in Lynn Lake and Murray Creek exceeded AWOC for drinking water and drinking
water/aquatic organisms, neither surface water body is used as a dri~ng water source. Therefore.
co~rison against AWOC for Ingestion of aquatic organisms is appropriate.
C. Soli Contamination
A soi gas survey was perlormed as part of the RI in those areas where TCE was historically stored,
disposed, or used as part of maintenance operations. These potertial sources areas are the East Gate
Disposal Yard, the North Uses Area, Wen L~ and Pit Area, and the DRMO Yard. The soil gas
Sa~ were analyzed for TCE, DCE. TCA. PeE. benzene. and tooene. The analytical results of the
soil gas survey were used to establish locations for soil borings in areas with the highest potential for
contamination. Figure 4A. 48, 4C Identify the locations of the soil gas survey and the soil borings.
The maximJm soU gas measurements for TCE and DCE were found in the East Gate Disposal Yard.
and for PeE and TCA in the North Uses Area and DRMO Yard, respectively. Benzene and toluene
were detected in soa gas in the North Uses Area.
A total of 25 soil boOngs were drilled throughout the potential source areas. All soil saJ1l)les were
anatyzed for TCE and DeE. A minimum of one boring per source area was analyzed for co~unds
on the HSL Refer to Table 4 for a summary of the boring anatytical results.
The primary contaminant. TCE, was disposed in various locations at the Logistics Center, until its use
was discontirtJed In the mid-1970s. Volatilization is the major mechanism for the retease of TCE from
surface soils. Once ~latilized, the dominant fate of TCE in the atmosphere is rapid photooxidation in
the tropOSphere; the atmospheric half-life Is estimated to be 6.8 days. The l..ogistics Center soils
generaJly consist of a sequence of sand and gravel and finer~rained unconsolidated seciments. In
addition, because of contiRJed construction at the Logistics Center, fiI was placed at scattered locations.
Based on the son organic matter partition coeffICient (K .. .. 126), TCE wiU rea
-------
TABLE 3
Fort Lewis Logistics Center
Surface Water Sampling Rcsults
Frequency 11 Range of Mean of Range of Ambient Water Quality Criteria (ugll)
Parameter of Detection Concentration Concentration DLs 21 Drinking Water 31 Aquatic Drinking 31
(ugll) (ug/l) (u~lI) and Aquatic Organisms Organisms Water only
TCE 27/49 0.12-46 5.3 0.1-0.2 2.7 80.7 2.8
DCE 16/49 0.1-23 4.1 0.1-0.2 - - -
1/ Frequency of Detection=number of detections/numbe~ of s3mpJes analyzed
2/ Range of DLs=range of detection limits
J/ Murray Creek and Lynn LAke are not a source of drinking water
Sediment Sampling Results
Prequency 11 Range of Mean of Range of
Parameter of Detection Concenlnltion Concenlnltion DLs 2l
(ugll) (ugll) (ugll)
TCE 5/10 0.49- 3.0 1.6 0.4
DCE 0110 - - 0.2-0.6
II Frequency of Detection=number of detections/number of samples analyzed
2/ Range of DLs=range of detection limits
"
-------
...
'I
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LEGEND
. - SOil GAS SAMPlE lOCATION
0- SOIL BORING lOCATION
...
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DISPOSAL YARD
( lANDFilL NO.2)
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.
1t.3 H.5 H-7 FORT LEWIS LOGISTICS CENTER
11.4 .H.6 .
. . @ It.a \ REMEDIAL INVESTIGATION I FEASIBILITY STUDY
.
1-4 1.5 ,.6 1-7
.1.3 . . . @),:' 1-8 \ FIGURE 4A
.
EAST GATE DISPOSAL YARD AND DRMO
J-3 YARD SOIL GAS SAMPLE AND
. J-5 .J-7 SOIL BORING LOCATIONS
. j ? 200 400
I I
-------
LEGEND
, . - SOIL GAS SAMPLE LOCATION
I : 0- SOIL BOAING LOCATION
NORTH USES AREA
C-1
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FORT LEWIS LOGISTICS CENTER
REMEDIAL INVESTIGATION I FEASIBILITY STUDY
FIGURE 48
NORTH USES AREA
SOIL GAS SAMPLE AND
-------
/
: ~
LEGEND
. - 80lL GAS 8AMPLE LOCATION
O. SOIL BORING LOCATION
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-------
TABLE4A
Fort Lewis Logistics Center
Soil Sampling Results
Inorganics Frequency 1/ Range of Mean of RAnge of 11
Parameter of Detection Concentration Coocentratioo DLs
(mglKg) (mg/Kg) (mglKg)
Aluminum 515 11200-14100 13200 -
Antimony 015 - - 0.8-14
Arsenic 515 1. 8-15 5.1 -
Barium 515 42-91 62.4 -
Beryllium 015 - - OA-1.2
Cadmium 515 1.0-2.7 2.1 -
Calcium 515 2340-4220 31.36 -
Chromium 515 6.9-29 16.7 -
Cobalt 515 7.3-13.0 9.7 -
Copper 515 9.4-24 17.9 -
Iron 5/5 9960-21200 16172 -
Lead 5/5 1.2-5.4 2.4 -
Magnesium 515 2240-5570 3998 -
Manganese 515 147-444 327 -
Mercury 4/5 0.1-1.9 0.6 0.1
Nickel I 515 15-29 22.4 -
Potassium 5/5 310-1870 857 -
Selenium 015 - - 0.1-1.2
Silver 015 - - 0.1-2.5
Sodium 515 476-726 611 -
Thallium 115 0.5 0.5 1.9-2.5
Vanadium 5/5 20-37 28 -
Zinc 5/5 17-40 29 -
Cyanide 015 - - 1.0-1.3
1/ Frequency of Detection=nUl1lber of detections/number of samples lUJalyzed
2/ Range of DLs=range of detection limits
-------
TABLE 4B
Fort Lewis Logistics Center
Soil Sampling Results
Volatiles . Frequeocy 11 Range of Mean of Range of
Parameter of Detection Concentration Concentration DLs 21
(mglKg) (mg/Kg) (mglKg)
Chloromethane 0/7 - 10-12500
Bromomethane 0/7 - 10-12500
Vinyl Chloride 0/7 - 10-12500
Chloroethane 0/7 - 10-12500
Methylene Chloride 0/1 - 6250
Acetone 0/2 - 10-12500
Carbon Disulfide 0/7 - 5-6250
l,l-Dichloroethylene (DCE) 0/7 - 5-6250
l,l-Dichloroethane (DCA) 0/7 - 5-6250
l,2-Dichloroethylene (DCE) 26/269 0.22-282000 21845 0.3-5
Chloroform 0/7 - 5-6250
1,2-Dichloroethane (DCA) 0/7 - 5-6250
2-Butanone 0/7 - 10-12500
1,1,1- Trichloroethane (TCA) 0/7 - 5-6250
Carbon Tetrachloride 0/7 - 5-6250
Vinyl Acelate 0/7 - 10-12500
Bromodichloromethane 0/7 - 5-6250
1,2-Dichloropropane 0/7 - 5-6250
cis -I, 3 - Dichloropropenc 0/7 - 5-6250
Trichloroethylene (TCE) 104/269 0.11-240000 4975 0.2-5
Dibromochloromethane 0/7 - 5-6250
1,1,2 -Trichloroethane 0/7 - 5-6250
Benzene 0/7 - 5 -6250
Trans-l,3-Dichloropropene on - 5-6250
Bromoform on - 5-6250
4-Methyl- 2-Penlanone 0/7 - 10-12500
2-Hexanone 0/7 - 10-12500
Teu8chloroethylene (pC E) 1/7 11000 11000 5
Toluene 1/7 14000 14000 5
l,l,2,2-Tetrachloroethane 0/7 - 5-6250
Chlorobenzene 0/7 - 5-6250
Ethyl benzene 1/7 9400 9400 5
Styrene 0/7 - 5-6250
Xylenes TOlal 1/7 78000 78000 5-15
2-Chloroethyl Vinyl etber on - 10-12500
11 Frequency of DetJ:ction=rJumber of detections/number of samples MJalyzed
21 Range of DLs=range of detection limits
-------
TABLE4C
Fort Lewis Logistics Center
Soil Sampling Results
Semivolatiles Frequency II RAnge of Mean of Range of
Parameter of Detection Concentration Concentration DLs 21
(mglKg) (mglKg) (mglKg)
Phenol 0/5 - - 360-430
bis(2 -Chloroethy 1) Ether 0/5 - - 360-430
2-Chlorophenol 0/5 - - 360-430
1 ,3 -Dichlorobenzene 0/5 - - 360-430
1,4- Dichlorobenzene 0/5 - - 360-430
Benzyl Alcohol 0/5 - - 360-430
1 ,2 -Dichlorobenzene 0/5 - - 360-430
2- Methylphenol 0/5 - - 360-430
bis(2 -Choloroisopropyl)E ther 0/5 - - 360-430
4-Methylphenol 0/5 - - 360-430
N - Nitroso- Dipropylamine 0/5 - - 360-430
Hexachloroethane 0/5 - - 360-430
Nitrobenzene 0/5 - - 360-430
Isophorone 0/5 - - 360-430
2-Nitrophenol 0/5 - - 360-430
2,4-Dimethylphenol 0/5 - - 1800-2150
Benzoic Acid 0/5 - - 360-430
bis(2 -Chlorocthoxy )Methane 0/5 - - 360-430
2,4- Dichlorophenol 0/5 - - 360-430
1,2,4- Trichlorobenzene 0/5 - - 360-430
Naphthalene 0/5 - - 360-430
4-Chloroaniline 0/5 - - 360-430
Heuchlorobutadiene 0/5 - - 360-430
4-Chloro- 3-Methylphenol 015 - - 360-430
2-Methyloaphthalene 0/5 - - 360-430
Heuchlorocyclopentadiene 0/5 - - 360-430
2,4,6- T richlorophenol 0/5 - - 360-430
2,4,5 - T richlorophenol 0/5 - - 1800-2150
2 -Chloronaphtha lene 0/5 - - 360-430
2-Nitroaniline 0/5 - - 1800-2150
11 FrequeDcy of [)etectioD=number of detectioDs/Dumber of S/Jmples analyzed
21 Range of DLs=range of detection Jjmits
-------
TABLE 4C
( cootinued)
SemivolatiJes Frequeocy 11 Range of Me.an of lUnge of
Pan.mcter . ofDcc.ection Coocentration Concentration DLs 2J
(mgIKg) (mgIKg) (mg/Kg)
Dimethyl Phthalate 0/5 - - 360-430
Acenapbthylene 0/5 - - 360-430
2,6-Dinitrotoluene 0/5 - - 1800-2150
3-Nitroaniline 0/5 - - 360-430
Acenapbthene 0/5 - - 360-430
2,4-Dinitropbenol 0/5 - - 1800-2150
4-Nitrophenol 0/5 - - 1800-2150
Dibcnzofuran 0/5 - - 360-430
2,4-Dinitrotoluene 0/5 - - 360-430
Diethylpbthalate 0/5 - - 360-430
4-Chloropbenyl-pbenyl Ether 0/5 - - 360-430
Fluorene 0/5 - - 360-430
4-Nitroaniline 0/5 - - 1800-2150
4,6- Dinitro- 2 - Methylphenol 0/5 - - 1800-2150
N - Nitrosodiphenylamine 0/5 - - 360-430
4- Bromophenyl-phenylether 0/5 - - 360-430
Hexachlorobcnzene 0/5 - - 360-430
Penl.1chlo~ophenol 0/5 - - 1800-2150
Phenanthrene 0/5 - - 360-430
Anthncene 0/5 - - 360-430
Di-n-Butylphthalate 0/5 - - 360-430
F1uoranthene 0/5 - - 360-430
Pyrene 0/5 - - 360-430
Butylbcnzylphthalate 0/5 - - 360-430
3,3' - Dichlorobcnzidine 0/5 - - 590-710
Benzo(a)Anthracene 0/5 - - 360-430
Chrysene 015 - - 360-430
bis(2 - Ethy lhcxyl )Phthalate 0/5 - - 360-430
Di-n-octyl Phthalate 015 -' - 360-430
Benzo(b)Fluoranthenc 0/5 - - 360-430
Benzo(k) FI uoran thene 0/5 - - 360-430
Benzo(a)Pyrene 0/5 - - 360-430
Indeno( 1 ,2,3-cd)Pyrenc 0/5 - - 360-430
Dibcnz(a,h)Anthracene 0/5 - - 360-430
Benzo(g,h,i)Perylenc 0/5 - - 360-430
Fort Lewis Logistics Center
Soil Sampling Results
1/ Frequency of DetJ:ctioa=aumber of delectioaslnumbcr of gmples analyzed
21 Range of DLs=TSl1ge of detJ:ctioo limits
-------
TABLE4D
F art Lewis Logistics Center
Soil Sampling Results
PesticidesIPCBs ' Frequency 11 Range of Mean of RAnge of
Param&.er of Detection Concentration Coocentration DLs 21
(mglKg) (mglKg) (mglKg)
alpha-BHC 0/5 - - 8.1-9.8
beta-BHC 0/5 - - 8.1-9.8
delta-BHC 0/5 - - 8.1-9.8
gamma - BHC(Lindane) 0/5 - - 8.1-9.8
Heptachlor 0/5 - - 8.1-9.8
Aldrin 015 - - 8.1-9.8
Heptachlor epoxide 0/5 - - 8.1-9.8
Endosulfan I 0/5 - - 8. 1-9.8
Dieldrin 0/5 - - 16-20
4,4'-DDE 0/5 - - 16-20
Endrin 0/5 - - 16-20
Endosul ran II 0/5 - - 16-20
4,4'-DDD 0/5 - - 16-20
Endosulfan sulfate 0/5 - - 16-20
4,4'-DDT 0/5 - - 16-20
Methoxychlor 0/5 - - 81-98
Endrin k~tone 0/5 - - 16-20
Chlordane 0/5 - - 81-98
Toxaphene 0/5 - - 160-200
Aroclor-l016 0/5 - - 81-98
Aroclor-1221 0/5 - - 81-98
Aroclor-I232 0/5 - - 81-98
Aroclor-1242 015 - - 81-98
Aroclor-1248 0/5 - - 81-98
Aroclor-1254 0/5 - - 160-200
Aroclor-1260 0/5 - - 160-200
1/ Frequellcy of Detection=llumber of detections/llumber of samples lllJalyzed
2/ Rallge of DLs=rallge of detectioll limits
-------
VII. SUMMARY OF SITE RISKS
The baseline risk assessment considered both human health risks and ecological risks. The human
receptors considered were on1)051 wof1(ers, on-post residents, and off-site residents. The biological
receptors Included aquatic organisms and local small mammals. The Army prepared a human health
and ecological endangerment assessment using the Maxirrom Acceptable Concentration (MAC)
methodology (Rnal Endangerment Assessment Report. February 1990). Because EPA generally does
not use or reconvnend the MAC approach, EPA Region 10 also prepared an assessment of human
health risks at the site using -EPA Region 10 Exposure Parameters- (January 31, 1990) and the Risk
Assessment Guidance for Superfund (RAGS): Human Health Evaluation Manual Part A (December
1989). The results are similar, In most cases, to the Army's Endangerment Assessment. The results
from the EPA human health risk assessment are diSaJssed below.
A. Human Health Risks
Adverse effects resulting from exposure to chemical contaminants have been grouped into two
categories: carcinogenic effects and noncarcinogenic effects (e.g., effects on organ systems, reproductive
and developmental effects). In the baseline risk assessment, risk has been estimated for exposure to
chemicals found at the Logistics Center. The risks presented do not inctude risks or rates of illness
(e.g., the normal cancer incidence is about 1 in 4 individuals) normally expected in the population.
Carcinogenic risk is estimated for chemicals known or expected to cause cancer as the Incremental
probability of an Riividual developing cancer over a lifetime as a result of exposure to a carcinogen.
To estimate this risk, a mathematical model is used to derive a relationship (slope factor) between
exposure (dose) and cancer incidence (response) from human or animal studies. Since there is much
uncertainty in this proceOJre, the upper 95% confidence lim of the dose-response relationship is
normally used to derive the slope factor so as not to underestimate the risk. Slope fadors are
combined with site exposure infonnation to estimate the incremental cancer risk, which is usually
expressed in scientific notation (e.g., 1 x 10-4). An excess lifetime cancer risk of 1 x 10" indicates that,
as a plausble upperbound, an individual has a one in ten thousand chance of developing cancer (over
the normal cancer risk of 1 in 4) as a result of site-related exposure to a carcinogen. For known or
suspectoo,"carcinogens, acceptable exposure levels are generally concentration levels that represent an
excess upperbound lifetime cancer risk to an individual of between 10" and 10. using information on
the relationship between dose and response (NCP 1990).
For noncarcinogens, the measure used to describe the potential for toxicity to occur in an Individual is
not expressed as a probability. The potential for noncarcinogenic effects is evaluated by comparing an
exposure level over a specified period (e.g., lifetime) with a reference dose derived for a similar
exposure period. This ratio of exposure to toxicity is called a Hazard Quotient. The Hazard Index (HI)
is the sum of more than one haZard quotient for multiple substances and/or multiple exposure pathways.
Potential noncarcinogenic effects may be of concern if the HI exceeds unity (i.e., HI > 1).
1. Chemicals of Concem
Data collected clIring the RI were used to identify chemicals present at the site. Media sampled
included groundwater, soils, surface water, and sediments. All chemicals were included in the
assessment unless: a) they were not detected in any of the above media; b) toxicity reference values
(i.e., Reference dose [Rfds] or cancer slope fadors) have not been developed for a chemical; or c) the
chemical is an essential rMnent. Two exceptions to these criteria are thallium and vinyl chloride.
Neither of these were detected in groundwater, but they were inclJded in the EPA assessment using
half of their respective detection limits (per RAGS guidance, 1990) since the risk at the detection limit
is significant. Ta.b6e 5 lists chemicaJs included in the baseline risk assessment based on the AI data
and above screening criteria.
2. Exposure Assessment
For this assessment, exposure was assumed to occur in the following settings/scenarios:
-------
TABLE
5
CHEMICALS OF CONCERN
CONTAMINANT GROUNDWATER SOIL SURFACE WATER
----------- ----------- --------------
Arsenic X X
Barium X X
Cadmium X X
Chromium X X
Lead X X
Manganese X X
Mercury X X
Nickel X X
.,
Thallium X X
Vanadium 'X X
,
Zinc X X
Trichloroethylene X X X
'cis 1,2 Dichloroethylene X X X
Toluene X
Ethylbenzene X
Total Xylenes X
Tetrachloroethylene X X
1,1,1 Trichloroethane X X
-------
a. Future on-post wor1
-------
TABLE
6
EXPOSURE POINT CONCENTRATIONS
GROUNDWATER SOIL
CONCENTRATION CONCENTRATION
(UGjL) (MGjKG)
AVE MAX AVE MAX
ARSENIC 3.2 4.2 4.4 4.4
BARIUM 43.0 53.0 48.0 48.0
CADMIUM 2.0 0.5 2.6 2.6
CHROMIUM 14.7 34.0 22.0 22.0
MANGANESE 1417.0 4000.0 423.0 423.0
MERCURY 0.3 0.6 0.1 0.1
NICKEL 85.3 100.0 27.0 27.0
THALLIUM 5.0 5.0 1.3 1.3
VANADIUM 35.0 35.0
ZINC 183.0 210.0 38.0 38.0
TRICHLOROETHYLENE 324.6 2400.0 120.0 240.0
cis 1,2 DICHLOROETHYLENE 24.3 130.0 141. 0 282.0
TOLUENE 7.0 14.0
ETHYL BENZENE 4.7 9.4
TOTAL XYLENES 39.0 78.0
TETRACHLOROETHYLENE 2.5 2.5 5.5 11. 0
1,1,1 TRICHLO~OETHANE 2.5 2.5 1.6 3 . 1
VINYL CHLORIDE 5.0 5.0 6.3 12.5
LEAD 17.0 28.0 5.4 5.4
SURFACE WATER CONCENTRATION (UGjL)
TCE
cis DCE
WATER BODY
MAX
MAX
LYNN LAKE
MURRAY CREEK
46.0
4.5
23.0
1.7
-------
TABLE 7 FUTURE OFFSITE RESIDENT RISK
GIWUNIJIIAI [I( , SOIL SURrACE IIAT[R I
I I (HURRAY CREEK) I
I I PAR T I CULA 1£ VAPOR FISH CONSUHPTION I
IINGESTION SHDIIERING I INGESTION INHALATION INHALATION ONLY I
I I I
ICANCER HAZARD CANCER HAZARD ICANCER IiAZARO CANCER ItAZARO CANCER IIAZARD CANCER HAZARD .1
CONTAMINANT IRISK INDEX RISK INDEX IRISK INDEX RISK INDEX RISK INDEX RISK INDEX I
TOTAL RISK
CANCER
RISK
HAZARD
INDEX
[[[1
I I I I I
ARSENIC I 2.3E-04 9.1E-02 I 2.5E-I0 1.6E-08 I I 2.3E-04 9.1E-02 I
BARIUM I 2.3E-02 I 1.8E-06 I I 2.3E-02 I
CADMIUM I 2.2E-02 I 6.1[-11 1.9E-08 I I 6.1£-11 2.2E-02 I
CHROMIUM I 1.5E-Ol I 3.5E-09 1.6E-08 I I 3.5E-09 1.5E-Ol I
MANGANESE I 4.3E-Ol I 5.1E-06 I I 4.3E-Ol I
MERCURY I 4.3E-02 I 1.2E-09 I I 4.3E-02 I
NICKEL I 1.1E-Ol I 1.8E-I0 4.9E-09 I I 1.8E-I0 l.lE-OI I
THALLIUM I 1. 5E +00 I 6. 5E -08 I I 1. 5E+00 I
VANADIUM I I 1.8E-08 I I 1.8E-08 I
ZINC I 2.3E-02 I 6.9E-10 I I 2.3E-02 I
TRICHLOROETHYLENE I 8.3£-04 7.0E+00 1.8E-03 I 5.5[-12 1.2E-07 3.5E-I0 7.3E-06 I 7.9E-07 9.5E-03 I 2.6E-03 7.0E+00 I
cIs 1,2 DICHLOROETHYL ENE I 1.4E-Ol I 5.1E-08 1.4£-05 I 2.7E-04 I 1.4E-Ol I
TOLUENE I 1 9.0E-ll 1.7E-08 I I 1.7E-08 I
ETHYL BENZENE I I 3.4 E -I 0 I.2E -08 I I 1.2E -08 I
TOTAL XYLENES I I 3.3£-09 2.3E-07 I I 2.3E-07 I
TETRACHLOROETHYLENE I 4.0E-06 5.4E-03 1.6E-05 I 1.4E-13 4.0E-09 2.9E-Il 8.2E-07 I I 2.0E-05 5.4E-03 I
1,1,1 TRICHLOROETHANE I 6.0£-04 1.1£-03 I 3.8£-11 4.9£-08 I I 1.7E-03 I
VINYL CHLORIDE I 3.6£-04 1.1£-01 9.1£-05 I 7.1E-12 4.6E-08 1.3£-07 8.2£-04 I I 4.5E-04 1.1E-Ol I
-------
TABLE 8 FUTURE ONPOST WORKER RISK
GROUNDWATER , SOIL SURFACE WATER I
1 I (L YNN LAKE) 1
I 1 PARTICULATE VAPOR FISH CONSUMPTION I
I INGESTION SHOWERING IINGESTION I NHALA 11 ON INHALATION ONLY 1
I I I
ICANCER HAZARD CANCER HAZARD ICANCER HAZARD CANCER HAZARD CANCER HAZARD CANCER HAZARD .1
CONTAMINANT IRISK INDEX RISK INDEX IRISK INDEX RISK INDEX RISK INDEX RISK INDEX I
TOTAL RISK
CANCER
RISK
HAZARD
INDEX
...............................=..&:2[[[c................a[[[
I I 1 I I
ARSENIC 16.72E-05 7.2E-D2 12.IIE-06 2.3E-039.72E-10 1.2E-07 1 I 6.9E-05 7.4E-021
BARIUM I 1.8E-02 I 4.9E-04 1.3E-05 I I 1.9E-02 1
CADMIUM I 1.7E-02 I 2.7E-032.34E-10 1.4E-07 I I 2.3E-10 2.0E-02 1
CHROMIUM I 1.2E-01 1 2.3E-03 1.33E-08 1.2E-07 1 1 I.3E-08 1.2E-Ol 1
MANGANESE 1 3.4E-01 I 1.1E-03 3.9E-05 1 I 3.4E-Ol 1
MERCURY I 3.4E-02 I 1.7E-04 9.2E-09 1 I 3.4E-02 I
NICKEL I 8.6E-02 I 6.9E-046.76E-I0 3.7E-08 1 1 6.8E-I0 8.6E-02 I
THALLIUM I 1.2[+00 I 9.2E-03 4.9E-07 1 I 1.2E+00 I
VANADIUM I I 2.6E-03 1.4E-07 I I 2.6E-03 I
ZINC I 1.8E-02 I 9.8E-05 5.2E-09 I 1 1.8E-02 I
TRICHLOROETHYLENE 12.41E-04 5.6£'00 5.3E-04 17.24£-07 1.7£-02 2.1£-11 9.0£-07 1.35£-09 5.6E-05 1 1.5[-06 1.8£-02 1 7.7E-04 5.6E+00 I
cis 1.2 DICHLOROETHYLENE I l.lE-OI I 7.3E-03 3.9E-07 l.lE-04 1 2.0E-03 I 1.2E-Ol I
TOLUENE 1 1 2.4E-05 6.8E-I0 1.3E-07 1 1 2.4E-05 I
ETHYL BENZENE I I 4.8£-05 2.6[-09 1.3E-07 I I 4.8E-05 I
TOTAL XYLENES 1 I 2.0E-05 2.5E-08 1.8£-06 1 1 2.2E-05 I
TETRACHLOROETHYLENE 11.17E-06 4.3E-03 4.7E-06 11.54E-07 5.7E-04 5.35E-13 3.0E-081.17E-I0 6.7E-06 I 1 6.0E-06 4.9E-03 1
1.1.1 TRICHLOROETHANE I 4.8E-04 3.IE-04 I 1.8E-05 2.9E-I0 3.7E-071 I 8.0£-04 I
VINYL CHLORIDE 11.05E-04 8.6E-02 2.7E-05 17.89E-06 6.4E-032.72E-l1 3.5E-074.92E-07 6.3E-03 1 I 1.4E-04 9.8E-02 I
asa===================================================================================================================C==============C==CC2=&=..===2~U=..............=1
TOTALS
-------
TABLE 9 FUTURE ONPOST RESIDENT RI~K
GROUND\lATER SOIL SURFACE \lATER I TOTAL RISK
I (LYNN LAKE) I
I PART ICULAlE VAPOR FISH CONSUMPTION I
I INGESTION SHO\lERING INGESTION INHALATION INHALATION ONLY I
I I
ICANCER HAZARD CANCER HAZARD CANCER HAZARD CANCER HAZARD CANCER HAZARD CANCER HAZARD I CANCER HAZARD
IRISK INDEX RISK INDEX RISK INDEX RISK INDEX RISK INDEX RISK INDEX I RISK INDEX
...................................==.............................................=.......==.......:=..................=..=..................................................
I I I I
ARSENIC \2.31E-04 9.1E-02 I 1. 13E-05 3.6E-03 2.79E-09 1. 8E -07 I I 2.4E-04 9.4E-02
BARIUM I 2.3E-02 I 7.9E-04 1.9E-05 I I 2.4E-02
CADM IUK 1 2.2E-02 I 4.3E-036.70E-I0 2.1E-07 I 1 6.7E-I0 2.6E-02
CHROH \UM I 1. 5E-Ol I 3.6E-03 3.81E-08 1.8E-07 I I 3.8E-08 1. 5E-Ol
MANGANESE I 4.3E-Ol I 1.7E-03 5.6E-05 I I 4.3E-01
MERCURY I 4.3E-02 I 2.7[-04 1.3E-08 I I 4.3E-02
NICKEL I 1.1E-Ol I 1.IE-03 1.94E-09 5.4E-08 I I 1.9E-09 1.1E-Ol
THALLIUM I 1. 5E+00 I 1. 5E -02 7.1E-07 I I 1.6E+00
VANADIUM 1 I 4.1E-03 2.0E-07 I I 4.1E-03
ZINC I 2.3E-02 I 1. 6E -04 7.6E-09 I I 2.3E-02
TRICHLOROETHYLENE 18.30E-04 7.0E+00 1. 8E -03 I 3.86E-06 2.7E-02 1.72E-I0 1.3E-06 I.11E-08 8.1E-05 I 3.2E-06 3.9E-02 I 2.6E-03 7.1E+00
cis 1,2 DICHLOROETHYLENE I 1. 4E-Ol I 1. 2E -02 5.6E-07 1.6E-04 I 6.3E-03 I 1.6E-Ol
TOLUENE I I 3.8E-05 9.8E-I0 1 . 9E -07 I I 3.9E-05
ETHYL BENZENE I I 7.7[-05 3.8E-09 l.9E -07 I I 7 . 6E - OS
TOTAL XYLENES I I 3.2E-05 3.6E-08 2.6£-06 I I 3.5£-05
TETRACHLOROETHYLENE 14.01E-06 5.4E-03 1. 6E -05 I 8.21E-07 9.1E-04 1.53E-12 4.4[-08 3.36[-10 9.6[-06 I I 2.1E-05 6.3[-03
1.1.1 TRICHLOROETHANE I 6.0E-04 1.IE-03 I 2.9[-05 4.2E-I0 5.4£-07 I I 1.7 [ -03
VINYL CHLORIDE 13.61E-04 I.IE-Ol 9.1E-05 I 4.21E-05 1.0E-02 1.56E-I0 5.0E-07 2.82E-06 9.lE -03 I I 5.0E-04 1.3[-01
..............................====.==.====.====.=............=..=..=...=.======..========"===============.======.==.==:===.====.:===.=._==...=..=.......................=....
TOTALS
1.4E-03 9.7E+00 1.9E-03 1.1E-03
5.8E-05 8.4£-02 4.4E-08 8.0E-05 2.8E-06 9.3£-03
3.2E-06 4.6E-02
-------
Currently. neither a reference dose nor a cancer slope factor are available to quantitatively evaluate risk
from lead exposure. Concentrations of lead In unfiltered groundwater samples were found to range from
10 to 20 ugll. In a memorandum dated June 21, 1990 from EPA OffIce of Emergency and Remedial
Response (OERR) and Office of Waste Programs Enforcement (OWPE) to EPA Region IV, it was
recommended that a final cleanup level of 15 ug/1 for lead in groundwater usable for drinking water is
protective for Superfund remedial actions. A concentration of lead of 15 ugli in drinking water should
generally correlate with a blood lead level below the concern level of 10 Ugldl. It is not clear whether
site data from the Logis1ics Center represent a significant exceedance of this level, nor whether lead
is natural or anthropogenic (man-made) in nature. Soil concentrations of lead ranged from 1.2 to 5.4
mgt1<.g over the Logis1ics Center. These levels may be co~ared to the sugges1ed lead cleanup levels
of 500 to 1000 mglkg for Superfund remedial actions (OWSER Directive #9355.4-02). Further
discussion of lead is included in the section entitled Remediation Goals.
The estimated carcinogenic risk from vinyl chloride of > 1 x1 O~ resulted principally from the use of 5 ug/1
(one-half the detection limit) as the groundwater exposure point concentration. Vinyl chloride has not
been detected in any groundwater well to date.
Arsenic also exhibtted a carcinogenic risk of > 1 x 10'" for groundwater ingestion in the off-site resident
exposure. The e~sure concentration for arsenic in groundwater of 4.2 ugll may' be lower than the
background concentration for arsenic in the Fort Lewis area. Further discussion of arsenic is included
in the section entitled Remediation Goals.
4. Uncertainty
Major components of the assessment which decreased the certainty of the results were the toxicity
reference values used. dermal contact pathway risks, and site characterization data. Due to the
uncertainty in these and other areas, conservative assumptions were made in order to be protective of
human health. Therefore, cancer and noncancer risk estimates must be carefully interpreted. This is
particular1y i~rtant when evaluating noncarcinogenic effects where uncertainty factors 01 2 to 3 orders
of magnitude are used in dose-response assessment. Given this uncertainty and other conservative
assumptions in the exposure assessment, exceeding a hazard index or quotient of 1.0 by several fold
may not be signifICant.
5. ToxicitY Characteristics
A brief discussion of the toxicity of the three major contaminants of concern is presented below.
Trichloroethylene (TCE): Acute effects from inhalation of high air concentrations of TCE have been
shown to induce anesthetic, analgesic, neurotoxic and behavioral effects (USEPA 1985). Principal
targets for inhaled TCE are the central nervous system (CNS), liver, kidney, and hematological system
(ATSDR 1988). The acute oral lethal dose of TCE in laboratory rats is 7,193 mglkg (NIOSH 1984).
Chronic effects in workers ocaJpationally exposed to TCE concentrations (14 to 85 ppm) for an average
of 3.75 years experienced effects such as vertigo, headache, and short-term memory loss (ATSDR
1988). In long-term studies with experimental animals, principal target organs following chronic
exposures are the CNS, liver, kidney, and hematological system.
Studies investigating the carcinogenic potential of TCE found that TCE produced hepatocellular and
testicular Leydig cell carcinomas as well as renal and lung adenomas. Under EPA's Proposed
Guidelines for Carcinogen Assessment, TCE is classified as a probable human carcinogen.
Cis 1,2 - DICHLOAOETHYLENE (DCE): In humans, 1,2-DCE is a central nervous system depressant
at high concentrations. Hepatic effects. including significant microscopic liver changes, have been
observed in studies conducted where rats received 200 mgli of DCE in drinking water (Quast at aI.,
1983). In another study, liver enzyme levels were increased in rats given a single 400 mglkg dose
(Jenkins at aI., 1972). .
-------
According to EPA's proposed guidelines for carcinogenic risk assessment, cis-1,2-OCE has been
classified in Group D. This category applies to agents for wt\k:h there Is Inadequate evidence 01
carcinogencity from animal studies.
TETRACHLOROETHYLENE (PeE): The principal toxic effects of PeE In ~rnans and animals from
both acute and longer-term exposures Include central nervous system (CNS) depression and fatty
infiltration of the liver and kidney with concomitant changes in serum enzyme levels Indicative of tissue
damage. Hepatoxic effects reported in humans exposed to PeE inctude cirrhOSis, toxic hepatitis, liver
cell necrosis, hepatomegaly, and altered liver function (EPA, 1985).
EPA's Carcinogen Assessment Group has classified PCE in Group B2 - Probable Human Carcinogen.
Significantly increased dose related incidences of hepatocellular carcinomas were observed in mice
exposed during inhalation studies (National Toxicology Program [NTP), 1986). In the NTP study,
increased incidences of mononuclear cell leukemia were seen in both sexes of rats and increased dose-
related incidences of renal adenomas and carcinomas were seen in males only.
B. Environmental Risks
The results of the qualitative ecological assessment indicate that the concentrations of TCE and DeE
in surface water and sediments of the on-post and off-post lakes do not result in adverse toxicological
effects to aquatic organisms. In each of the lakes, maximum concentrations of TCE and OCE were
below levels necessary to trigger acute effects. TCE concentrations in sediments were very low and
DCE was not detected in any of the sarT'4)les collected. Interstitial water concentrations estimated from
the sediment concentrations of TCE were well below those necessary to initiate acute and chronic
aquatic toxicity.
No endangered species or critical habitats were identified at the Logistics Center.
VIII. DESCRIPTION OF ALTERNATIVES
A. 5011 Alterna1lveS
,.
Soil alternatives were evaluated within the FS process while the baseline risk assessment was being
finalized. The baseline risk assessment subsequent1Y indicated that the levels of residual soil
contamination correspond to a carcinogenic risk of 1x10 and a noncarcinogenic hazard index of 0.06.
This baseline risk for soil is within the acceptable exposure levelS (i.e., between 10" and 1 0") that are
protective of human health as proroolgated in the NCP (55 FR 8848). Therefore, remediation of soil
is not included as part of the seleCted remedy.
B. Groundwater Alternatives
A complete listing of the applicable or relevant and appropriate requirements (ARARs) are listed and
summarized in the section entitled Statutory Determinations.
The principal regulations for the groundwater alternatives are the Clean Water Ad (CWA)(33 USC
1251), the Safe Drinking Water Act (SDWA) (40 use 300), the Resource Conservation and Recovery
Act (RCRA)(42 USC 6901), the Water Pollution Control Act (Chapter 90.48 RCW), and the Clean Air
Act (Chapter 70.94 RCW).
Under the CWA: 1) State Antidegradation Requirements/Use Classification require every state to classify
all the waters within its boundaries according to intended use. The aquifers beneath the Logistics
Center, including the contaminated unconfined aquifer, are Class I (i.e., drinking water) aquifers; 2) CWA
section 304 specifies arrbient water quality criteria (AWQC) which were developed tor the protection of
human health and aquatic lite. The AWQC were compared to contaminant levels found in surface
waters potentially affected by the Logistics Center (Table 3) and are discussed further in the section'
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entitled Remediation Goa"; and 3) CWA section 301 (b) requires that, at a minim.Jm, all direct
discharges meet ted1nology-ba8ed IfnIs for conventional pollutant control technology. Because there
are no national efrlJent IimItattons regulations for releases from CERCLA sites, tecMology-based
treatment requirements are detenn!ned on a case-by-case basis using best professional judgement. Air
stripping was the type of pollutant control technology evaluated for the groundwater alternatives. Air
stripping is a proven technology for treatrnen of the V~ntaminated groundwater. For exa~Ie, the
technology should treat TCE to better than MCLs (approximately 0.5 ug/I).
CERCLA section 121(d)(2)(A) requires on-site CERCLA remedies to attain standards or levels of control
established under the SDWA (I.e., MCLs or MCLGs [maxlrrom contaminant level goalsD. According to
the NCP (55 FR 8848), where MCLGs are set at zero, the remedial actions shall attain MCLs for
ground or surface waters that are currer( or potentlaJ sources of drindng water. MCLs are the
remediation goaJs for the logistics Center and are discussed later in the section entitled Remediation
Goals.
Under RCRA, the principal wastes (i.e., TCE and DCE) are RCRA-listed spent halogenated solvents
(FOO1). Because the groundwater is contaminated by RCRA hazardous wastes, it roost be managed
as a hazardous waste until it no longer contains the hazardous wastes. An air stripper will be used
to treat the contaminated groundwater such that the concentration of hazardous wastes will be below
health-based levels (i.e., less than MCLs or MCLGs). After treatment, the groundwater will no longer
contain a hazardous waste and would not be regulated as a hazardous waste.
Ambient concentrations of toxic air contaminants In the Puget Sound region are regulated by the Puget
Sound Air Pollution Control A/;}ercy (PSAPCA) pursuant to the State of Washington Clean Air Act
(Chapter 70.94 RCW) and I~ementation of Regulations for Air Contaminant Sources (Chapter 173-
403 WAC).
The Best Available Control Technology (BACT) is required by PSAPCA for new sources of toxic air
contaminants. BACT means an emission limitation based on the maximum degree of reduction possible
for a given source through application of production processes and available methods. On a case-by-
case basis, PSAPCA determines the achievable BACT based upon factors such as energy,
environmental, and economic ifT1)ads. Subsequent to BACT, PSAPCA evaluates toxic air contaminant
emissions from the source against Acceptabfe Source Impact Levels (ASILs) adopted by the Agency.
The ASIL fOr TCE is 0.8 uglmJ. Pre-conceptual design concentrations from the FS estimate TCE air
emissions from the air strippers at 0.060 UglmJ.
The air stripping vendor may perform a bench-scaie treatability study to obtain infonnation to design the
air stripper. A pilot study may not be required for the air stripper since air stripping is a weU-developed
technology. A pUrf1) test may be required to obtain engineering data for the design of the extraction
and discharge systems. Also, the need for metals removal to facilitate the air stripping technology will
be evaluated during design.
1. No Action (monitorina only)
The NCP requires that the -no action- altemative be considered for every site. Under this alternative,
no remedial actions would be taken beyond those already in place (Le., providing an alternative water
supply to residents with contaminated wetls). Monitoring would be i~lemented only to evallate
changes in the contaminant plume. The "no action- alternative is not protective of human health or the
environment and does not meet ARARs. Since this altemative does not change contaminant
concentration or exposure, the residual risk is equivalent to the baseline risk.
2. Extract and Treat Downoradient 01 the Site
The purpose of this alternative is to reduce and control the release of the contaminants into the
unconfined aquifer downgradient of the Logistics Center. The alternative consists of instaling extraction
wells downgradient (i.e., northwestem boundary) of the Logistics Center. During operation, groundwater
would be pu~ from the wells and treated in an air stripping tower. Assuming a treatment rate of
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5000 gallons per minute (gpm), an influent TCE concentration of 70 ug!I, and an air-liquid ratio of 50:1,
the air stripper should treat the TCE to less than 5 ugll.
The treated groundwater would be discharged back to the ground into passive discharge trenches
downgradient of the extraction wells. The exact number and location of extraction wells and discharge
trenches will be determined during design.
Administrative and institutionaJ controls may inClude provisions for alternate water supply, access
restrictions, notification to appropriate agencies, and public awareness.
If additional existing private drinking water weBs are found to be contaminated, the residents will be
offered connections to an altemate water supply (e.g., Lakewood Water District). The Army will update
the affected communities and rnJnicipalities of the remedial action progress, continue to discourage use
of private wells for drinking water purposes, and monitor the contaminated private wells.
A long-term monitoring program would be institUted using both on- and off-site wells to measure the
effectiveness of the remedial action during implementation.
Under alternative 2, remediation of the Logistics Center contaminated groundwater plume may require
50 years or more.
The reasonable maxirnJm exposed (RME) individual for the off-post resident scenario experiences a
combined residual risk at remediation goals for all contaminants and all pathways of 5 x 10's
(carcinogenic risk) and a hazard index of 0.91 (noncarcinogenic risk).
3. Extract and Treat Downaradient of the LOGistics Center and Near Source Areas
The purpose 01 this alternative is to reduce and control the release of the contaminants into the
unconfined aquifer beneath and downgradient of the Logistics Center in a significantly shorter time
period than Alternative 2. Also, the NCP (55 FR 8849) requires that for groundwater response actions,
alternatives be developed that attain site-spedfic remediation levels within different restoration time
periods using one or rrore different technologies.
I
The alternative consistS of installing extraCtion wells downgradient (i.e., northwestern boundary) of the
Logistics Center and near the areas of highest contaminant concentration in the groundwater. The exact
number and location of extraction wells will be determined during design. Placing wells in the areas
of highest contamination should expedite remediation of the groundwater beneath the Logistics Center.
During operation, groundwater would be PUn1>ed from the wells and treated in air stripping towers at
two locations. For the downgradtent treatmeri system, the FS assumed a flowrate of 5000 gprn and
an influent TCE concentration of 70 u~. For the treatment system near the areas of highest
contamination. the FS assumed a fbwrate of 2000 gpm and an influent TCE concentration of 145 ugJ1.
Based on these assu~ions and an air-liquid ratio of 50:1, the air stripper should treat the TCE to less
than 5 ugJ1.
The treated groundwater would be discharged to the ground into passive discharge trenches. One
trench will be located upgracJient from the wells in the areas of highest contaminant concentrations.
Locating a discharge trench upgradient would expedite groundwater remediation by facilitating flushing
of secondary sources.
This alternative includes the administrative and institutional controls and long-term monitoring as
described in Alternative 2.
Remediation of the Logistics Center contaminated groundwater plume would be completed in
approximately 30 years.
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The reasonable maxiroom exposed (RME) Individual for the off-post resident scenario experiences a
combined residual risk at remediation goals for aI contaminants and all pathways of 5 x 10'"
(carcinogenic risk) and a Hazard Index of 0.91 (noncarcinogenic risk).
IX. SUMMARY OF COMPARATIVE ANAlYSIS OF ALTERNATIVES
The relative perfonna~ of each remedial alternative was evaluated in relation to three categories 0'
criteria: 1) threshold criteria (a required level of performance); 2) primary balancing criteria (technical
advantages and disadvantages); and 3) modifying criteria (overall evaluation). The nine evaluation
criteria and the results of the evaluation are discussed below.
A. Threshold criteria
The remedial alternatives were first evaluated in relation to the threshold criteria: overall protection 01
~man health and the environment. and compliance with ARARs. The threshold criteria rn.Jst be met
by all alternatives that are considered for further evaluation as remedies for the site. A summary 01 the
relative performance of the groundwater altematives is included in Table 10.
1. Overall Protection of Human Health and the Environment. This criteria addresses whether or not a
remedial alternative provides adequate protection and describes how risks are eliminated, reduced, or
controlled through treatment and engineering or i1stitutional controls.
Both alternatives 2 and 3 provide overall protection once remediation is complete by reducing the risk
to t1.Jman health and the environment from the contaminated groundwater. Because the groundwater
will meet MCLs after treatment and discharge. the unconfined aquifer may be restored for use as
dri~ing water in approximately 30 or 50 years. In addition, under both altematives. the groundwater
would be treated to effluent concentrations less than MCls before being discharged to the ground.
During remediation. the groundwater discharged to the aquifer would meet MCLs and would reduce the
risks downgradient of the Logistics Center.
Alternative 2 would have a greater irf1)act on hJrnan health and the environment because it would allow
at least 20 additional years of potential exposure to contaminated groundwater. Alternative 3
signifICantly reduces the time required for reme
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TABLE 10
SUMMARY OF GROUNDWATER ALTERNATIVES DETAILED ANALYSIS
G-3:
G-2: Combined Extraction
Extraction Along 1-5 and
Along 1-5, near Source Areas,
G-l: Air Stripping, Air Stripping,
Criteria . No Action and Discharge and Discharge
Overall Protection of
Human Health and
Environment Low Medium High
Compliance with
ARARs Low High High
Long-Term
Effectiveness
and Permanence Low High H'gh
Reduction of
Toxicity, Mobility, Low Medium High
and Volume
Short-Term
Effectiveness NIAll Medium High
Implementabi l1ty HI All Medium Med'um
I
State Acceptance Low Medium High
Community
Acceptance Low Medium High
Capital Cost 0 $2,654,000 $4,014,000
Operating Costs $32,240/yr2J $354,OOO!1 $517,OOO!l
$16,120/yrJI
Net Present
Horth $180,000 $6, 171 ,OOO~I fll $9,068,OO~1
(ial0~, n=30 yrs)
Net Present $9,084,0005' 11 $13,263,0005'
Horth $309,000
(i=41., n=30 yrs)
11 MIA-not applicable, assumes no remedial action.
~I Operating cost for first 2 years.
.31 Operating cost for remaining 28 years.
!I Cost not 'ncluding monitoring cost.
~I Cost inclu~ing monitor1ng cost.
fll Net Present Korth <1-101, n-50 years) - $6,352,000
11 Net Present Korth <1-41, n-50 years) - $10,636,000
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3. lona-term Effectiveness and Permanence. This criteria refers to the ability of a remedial alternative
to maintain reliable protection of human health and the environment once remediation goals have been
achieved.
Both remedial alternatives 2 and 3 are expected to remediate the groundwater to MCLs. They should
maintain reliable protection of human health and the environment once MCLs are met.
Both remedial alternatives provide treatment, but only with the proper operation and maintenance of the
extractionltreatment systE3m. In addition, a groundwater monitoring system must be implemented to
ensure that remediation goals have been achieved.
The no action alternative is not effective because remediation of the aquifer will not be achieved.
4. Reduction of Toxicity, Mobility, or Volume. This criteria refers to the anticipated performance of the
treatment technologies a remedial alternative may employ.
Alternatives 2 and 3 will reduce the volume of the contaminants in the groundwater, and the horizontal
and vertical movement of the contaminants. Both alternatives will reduce the concentration of the
contaminants to drinking water standards (MCls). The movement of the contaminants will be controlled
upgradient and downgradient of the extraction wells by the zone of influence created by the purf'4)ing
drawdown action.
Alternative 2 requires a longer period of time (SO years) to achieve a reduction in movement, and
volume of the contaminants. Also, since alternative 2 requires more time for remediation, it may allow
the contaminant to migrate to the lower aquifers, thus exacerbating the extent of contamination.
Alternative 3 takes less time (30 years) and also expeditiously addresses the areas of highest
contamination both by additional extraction and treatment in those areas and by flushing the secondary
sources in the groundwater.
The no action remedial alternative does not reduce the toxicity, movement, or volume of the
contaminants in the groundwater.
5. Short-term effectiveness. This criteria refers to the period of time needed to achieve protection and
any adverSe impacts on human health and the environment that may be posed during the construction
and ifT1Jlementation period until cleanup goals are achieved.
Alternatives 2 and 3 will require approximately six months to construct. Initially, short-term impacts of
these alternatives occur during construction. The potential for worker exposure is highest during
installation of the groundwater extraction wells and during operation and maintenance of the treatment
system. Appropriate health and safety regulations would be implemented (e.g., air monitoring, use of
personal protective equipment) during remedial action to provide protection to workers.
There are no short-term environmental impacts during construction of alternatives 2 and 3 that cannot
be readily controlled. For example, groundwater from well development will be analyzed for compliance
with regulatory requirements prior to discharge or disposal.
This criteria also addresses effectiveness during rernediation until cleanup goals are achieved.
Alternative 3 has less short-term impact on human health and the environment during remediation
because remediation is completed significantly faster than alternative 2. Alternative 2 increases the
short-term exposure to contaminated groundwater and emissions from the air strippers by approximately
20 years.
The no action alternative does not include construction or treatment of groundwater and therefore, the
risk to workers from these activities would not be present. However, potential exposure to contaminated
groundwater would continue indefinitely without remediation of the aquifer.
6. Implementability.
ThiS criteria refers to the technical and administrative feasibility of a remedial
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alternative. including the availability of goods and services needed to i~ement the selected remedy.
Alternatives 2 and 3 are designed such that rrinimal difficulties are expected during ~mentatlon.
The extractionltreatment system must satisfy groundwater withdrawal. treatment plant emission, and
discharge requirements. Air stripping of VOC~ntaminated groundwater is a proven and wldely-
available technology.
The no action alternative. requires no i~ementation other than ongoing monitoring.
7. Cost. This criteria refers the cost of implementing a remedial alternative. including operation and
maimenance costs.
The no action altemative indudes only the cost of operating the monitoring system. The 3O-year
present worth cost (assuming i . 10%) for no action is $180,000. This cost does not reflect the fad
that monitoring would continue for an indefinite period of time.
Altemative 2 has lower capital costs than alternative 3 because it uses only one treatment system
downgradient of the Logistics Center. The 30-year present worth cost for capital and
operation/maintenance costs (assuming i = 10%) is $6.171.000. The SO-year present worth cost
(assuming i = 10%) is $6,352,000.
Alternative 3 has higher capital costs than alternative 2 because it uses an additional treatment system
to extract and treat the groundwater. The 30-year present worth for capital and operationtmaintenance
costs (assuming i = 10%) is $9,068,000.
C. Modifying Criteria
Modifying criteria are used in the final evaluation of the remedial alternatives.
8. State Acceptance. This aiteria refers to whether the state agrees with the preferred remedial
altemative.
The Washington State Department of Ecology (Ecology) concurs with the selection of the preferred
remedial alternative. Ecology has been involved with the development and review of the Remedial
Investigation/Feasibility Study, the Proposed Plan, and the Record of Decision. .
9. Comrronitv Acceptance. This criteria refers to the public support of a given remedial alternative.
The results of the public comment period and the discussion during the public meeting on June 28.
1990. indicate that the residents of surrounding communities support the preferred remedial alternative.
Community response to the remedial alternatives is presented in the Responsiveness Sumrnary, which
addresses comments received during the public comment period.
X. THE SELECTED REMEDY
The selected remedy is Alternative 3 - Extract and Treat Downgradient of the Logistics Center and Near
Source Areas.
The selected remedy for the logistics Center operable unit addresses the principal threats posed by
the site by treating the groundwater and by flushing secondary source residual contarrination. The
remedy is designed to reduce exposure to the contaminated groundwater and to remediate the
groundwater to levels that are protective of human health and the environment.
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A. Major Components of the Selected Remedy
- Install groundwater extradlon wells capable of capCur1ng the groundwater contaminant plume In the
unconfined aquifer.
. Install on-site groundwater treatment fadlitles to remove contaminants from the colleded groundwater.
. To expedite groundwater remediation, Install groundwater extraction wells near areas of highest
concentration of contaminants and discharge treated groundwater upgradient of these extraction wells
to facilitate flushing secondary sources from the groundwater.
- Monitor the groundwater contaminant plume and the extractionltreatment system during groundwater
remediation activities to ensure that both groundwater and surface water remediation goals are achieved.
- Implement administrative and institutional controls that supplement engineering controls and minimize
exposure to releases of hazardous substances during remediation.
- Investigate the lower aquifer(s) to detennine the presence of contamination and to evaluate the extent
of contamination, if necessary. If contamination is found, a groundwater extraction system will be
installed which is capable of capturing the contaminant plume with subsequent treatment of the extracted
groundwater in the on-site treatment facility. The remediation goals specified for the unconfined aquifer
will also apply to any contaminated lower aquifers.
- Perform confirmation soil saI11>ling to ensure that all remaining sources of soil contamination have
been identified and characterized.
Based on information obtained during the remedial investigation and on an analysis of the remedial
alternatives, the Army, EPA and the State of Washington believe that the selected remedy will achieve
this goal. It may become apparent, during implementation or operation of the groundwater extraction
system and its modification that contamination levels have ceased to dedine over some portion of the
plume and are remaining constant at levels higher than the remediation goal. In such a case, the
system performance standards and/or the remedy may be reevaluated.
The selected remedy will inctude groundwater extraction for an estimated period of 30 years, during
which the system's performance will be carefully monitored on a regular basis and adjusted as
warranted by the performance data collected during operation. Modifications may include:
a.
discontinuing pumping at the individual wells where cleanup goals have been attained;
alternating pumping at wells to eliminate stagnation points;
b.
c. pulse pumping to allow aquifer equilibration and to allow adsorbed contaminants to partition
into groundwater; and
d. installing additional extraction wells to facilitate or accelerate cleanup of the contaminant plume.
It may become apparent during design, implementation, or operation of the effluent discharge system
that the system is not effective. For example, the discharge piping may clog because of the natural
water chemistry or the disturbed soils may prevent effective infiltration. In such a case, the discharge
system may be reevaluated. If necessary, other alternatives for effluent discharge would be considered
(e.g., discharge to surface water or to publicly-owned treatment wor1
-------
to human health and the environment. Existing conditions at the site pose a threat predominantly from
ingestion and vapor inhalation exposure to V~ntaminated groundvotater.
The goal of this remedial ad ion is to restore groundwater to its beneficial use, which is, at this site, a
dr1~ing water source. The groundwater will be restored to levels consistent with state and Federal
ARARs which will result in a oJrTIJlative excess cancer risk not to exceed' 0". Remediation levels will
be anained throughout the contaminated plume.
Remediation goals were' established for chemicals with levels that either: ') exceed an ARAR; or 2) are
not protective of public health or the environment. MCUMCLGs are exceeded for three compounds:
TCE, DeE, and PCE. Total risks for arsenic (As), thallium, TCE, PCE, and vinyl chloride exceeded a
, O. probability for carcinogenic risk and/or a Hazard Index greater than 0.5 for noncarcinogenic risk.
The baseline risks for thallium and vinyl chloride were calculated using one hatf of the detedion limit
(per RAGS guidance) for each compound. For the future off-site resident scenario. this corresponds
to an excess cancer risk of 4.5 x 10" for vinyl chloride and a Hazard Index of 1.5 for thallium.
Remediation goals for these compounds were not established beCause: ') there is no history of use
or disposal of thallum or vinyl chloride; and 2) neither cor11>OUnd was detected in any well during
groundwater sampling. Because vinyl chloride is a degradation product of TCE under anaerobic
conditions. the Army will include vinyl chloride analysis in the ongoing groundwater monitoring with
subsequent air stripping treatment, if necessary.
The total baseline cancer risk for arsenic in soil and groundwater is estimated to be 2 x 10". If this
baseline risk for arsenic is added to the combined risk at remediation goals (Table 11), the total risk
is then estimated to be 2.8 x 10". It is not clear whether groundvotater concentrations from downgradient
wells represent. a significant difference of arsenic levels in upgradient wells, nor whether the arsenic is
natural or anthropogenic in nature.
Remediation of arsenic at the Logistics Center is not induded in the selected remedy for tl1e following
reasons:
A. The upgradient wells: 1) were installed at varying depths within the hydrogeologic units;
2) were sampled during different sampling events; and 3) samples were analyzed by
I different laboratories. These differences may explain the range of arsenic upgradient
groundwater concentrations of from less than 5 ugll to 8 ugll. Due to a naly1 ical
measurement uncertainty, it is not clear whether groundwater concentrations from
downgradient wells represent a statistically significant difference from upgradient wells.
B. Levels of arsenic in groundwater are highly variable in Westem Washington. Although the
sources are not known, arsenic has been found in a variety of deposits ranging from glacial
drrtt to igneous bedrock. In Pierce County, Washington, elevated arsenic levels have been
found in glacialfluvial deposits composed chiefly of sands and gravels. Naturally ocaming
arsenic is found in arsenopyrite and other arsenic~ rod
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TABLE 11. COMBINED RISK AT REMEDIATION GOALS
II. 2/. 31
, REMEDIATION GOALS (RG) I COMBINED RISK AT RG I
I ' , I
I , ONPOST I OFF POST I ONPOST I
I I RESIDENT I RESIDENT I WORKER I
, ' I I I
'Groundwater Surface Water Soil I Cancer Hazard ICancer Hazard ICancer Ha za rd I
I (ugl1) (ugl1) (mg/kg) IRlsk Index IRlsk Index IRlsk Index I
...tS.~..~~E=======~===2~C==...==2..C=2...S.CC==C..t.B.......e..c.==.c.'...a=..==.~.=............................................1
I I I I I
BARIUM ' I 2.4E-02 I 2.3E-02 I 1. 9E -02 I
CADM IUM I I 6.7E-I0 2.6E-02 I 6.1E-11 2.2E-02 I 2.3E-10 2.0E-02 I
CHROMIUM I I 3.8E-08 1.5E-Ol I 3.5E-09 1. 5E-Ol I 1.3E-08 1. 2E -01 I
MANGANESE I I 4.3E-01 I 4.3E-Ol I 3.4E-Ol I
MERCURY I I 4.3E-02 I 4.3E-02 I 3.4E-02 I
NICKEL ' I 1. 9E -09 l.lE-Ol I 1. 8E -10 I.IE-Ol I 6.8E-10 8.6E-02 I
THALLIUM I I I I I
VANADIUM I I 4 . IE -03 I 1.8E-08 I 2.6E-03 I
ZINC I I 2.3E-02 I 2.3E-02 I 1.8E-02 I
TRICHLOROETHYLENE I 5 80 I 1.3E-05 8.IE-02 I 6.3E-06 2.4E-02 I 3.8E-06 4.6E-02 I
cIs 1.2 DICHLOROETHYL ENE I 70 , 9.4E-02 I 7.6E-02 I 6.9E-02 I
TOLUENE I I 3.9E-05 I 1. 7E -08 I 2.4E-05 I
ETHYl BENZENE ' I 7.8E-05 I 1.2E-08 I 4.8E-05 I
TOTAL XYlENES I I 3.5[-05 I 2.3[-07 I 2.2E-05 I
TETRACHLOROETHYLENE I 5 I 4.1E-05 1. 2E -02 I 4.0E-05 I.IE-02 I 1. 2[ -05 9.1E-03 I
1.1.1 TRICHLOROETHANE I I 1.7[-03 I 1. 7[ -03 I 8.0[-04 I
[[[
TOTALS
5.~[-05 1.0[+00
4.6[-05 9.IE-01
1.6E-05 7.7[-01
--------------------------
1\ Total rIsk I~ r.nlculateu by combInIng rl~lk across all exposure pathways and medIa.
2\ The Hazard Index Is calculated by addIng noncarcInogenic risks for all chemicals without grouping by
sImilar toxic endpoint or mechanism.
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determined that soU at the logIsticS Center Is not. within levels that are protective of roman health or
the environment. the need for treatment will be reevaluated.
For surface water, the levels of TCE found do not exceed the AWac for the designated uses of each
water body. A remediation goal for TCE of 80 ugII (aquatic organisms only) was established due to
the potential for Mure increases In surface water concentrations from groundwater contamination. The
selected remedy is expected to remedy the flow of contaminated groundwater into nearby creeks or
lakes. No AWaC have been developed for cis 1, 2 - DCE.
Table 11 sunvnarizes the remediation goals and presents the combined risk for all pathways and media
for the oni>Ost resident, the off1)Ost resident. the on-post worker.
XI. THE STATUTORY DETERMINATIONS
The selected remedy meets statutory requirements of Section 121 of CERCLA. as amended by SARA.
and to the extent practicable. the National Contingency Plan. The evaluation criteria are discussed
below.
A. protection of Human Health and the Environment
The selected remedy protects roman health and the environment through extraction and treatment of
the vOC~ntaminated groundwater. The contaminants will be pennanently removed from the
groundwater by air stripping. The volatile dissolved gases will be transferred to the air stream for
treatment in accordance with applicable emissions regulations.
Extraction of the VOC-contaminated groundwater also will eliminate the threat of exposure to the most
mobile contaminants from ingestion or inhalation of contaminated groundwater. A baseline risk for the
oH-post residential scenario associated with these exposure pathways is estimated at 3.3 x 10-3 for
carcinogenic risk with a HI = 9.7 for noncarcinogenic risks. By extracting the contaminated groundwater
and treating it by air stripping. the cancer risk will be reduced to 5 x 10-5 and the HI will decrease to
0.91.
As part of the FS, computer olSpersion modeling using the ISCL T method was used to detennine the
worst~se annual TCE concentration of 0.060 uglmJ downwind of the air stripping towers. This airborne
concentration corresponds to a cancer risk of 3.7 x 10.7 and a Hazard Index of 1.5 x 10". These levels
are within the range of acceptable exposure levels of 1 0-4 and 1 O. and the Hazard Index does not
exceed one. The need for enission controls will alSo be evaluated during design in cofT1)liance with
state ARARs. Therefore, no short-tenn threats or adverse cross-media impacts will result from
implementing the selected remedy.
B. Attainment of Applicable or Retevant and Approprtate Requirements of Environmental Laws
~ - . --'
The selected remedy of groundwater extraction. on-site treatment, and passive discharge of the treated
groundwater will comply with all appI1cable or relevant and appropriate requirements (ARARs) of Federal,
as well as more stringent, promulgated State environmental and public health laws.
1. Applicable or Relevant and ADoroDriate Reouirements (ARARs)
Both groundwater extractionltreatment alternatives will comply with all action-, chemicaI-, and location
specific ARARs. The ARARs are listed below.
Action-Soecific
- State of Washington HazardouS Waste Management Act (Chapter 70.1050 RCW) requirements for
dangerous waste and extremely hazardous waste as codified in Chapter 173-303 WAC.
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. State of Washington Hazardous Waste Cleanup-Model Toxies Control Act (Chapter 70.105D RCW)
requirements 'or the identification, Investigation, and clean up of hazardous waste sites are being
developed in two phases. Phase I, which defines the administrative process for identifying, investigating,
and cleaning up hazardous waste sites, is applicable. All cleanup actions shall use permanent solutions
to the maximum extent practicable.
- Substantive water resource antidegradation fundamentals of the State of Washington Pollution Control
Act (Chapter 90.48 RCW) and Water Resources hj, of 1971 (Chapter 90.54 RCW).
- Requirements of the State of Washington for water well construction as set forth in Chapter 18.104
RCW (Water Well Construction) and codified in Chapter 173-160 WAC (Minimum Standards 'or
Construction and Maintenance of Wells).
- State of Washington requirements (Chapter 173-154 WAC) for the management of groundwater in a
manner that protects. to the extent practicable. the upper aquifers of multiple aquifer systems from
depletions, excessive water level declines or reductions in water quality.
- Water Pollution Control Act (Chapter 90.48 RCW), Pollution Disclosure Act of 1971 (Chapter 90.52
RCW), and Water Resources Act of 1971 (Chapter 90.54 RCW) require the use of all known, available.
and reasonable methods (AKARTs) of treatment prior to discharge to groundwater.
- Requirements of the Clean Water Act section 402 (40 CFR Parts 121-125) for effluent discharge would
be applicable if it is necessary to modify or use an alternate effluent discharge system.
- Requirements of the State Waste Discharge Permit Program (Chapter 173-216 WAC) for discharge
of waste materials into groundwater.
- State of Washington requirements for hazardous waste operations conducted at uncontrolled hazardous
waste sites as set forth in WAC 296-62 Part P (Hazardous Waste Operations and Emergency
Response).
Chemical-Soecific
Groundwater extractionltreatment activities will meet the following chemical-specific ARARs:
- Federal requirements of the Safe Drinking Water Act (40 USC 300) for groundwater used as drinking
water set forth in 40 CFR 141. Specifies maximum contaminant levels (MCLs) for public drinking water.
- Requirements for land disposal of RCRA hazardous wastes as established in 40 CFR 261. 264, and
268 Subpart D.
The principal wastes (i.e., TCE and DCE) are RCRA listed spent halogenated solvents
(F001). Because the groundwater is contaminated by RCRA hazardous wastes, it rrust
be managed as a hazardous waste until it no longer contains the hazardous wastes.
An air stripper will be utilized to treat the contaminated groundwater such that the
concentration of the hazardous wastes will be below health based levels (i.e.. less than
MCLs or MCLGs). Consequently, the groundwater will no longer contain hazardous
wastes, and thus would not need to be managed as a hazardous waste.
- Water Pollution Control Act (Chapter 90.48 RCW), Pollution Disclosure Act of 1971 (Chapter 90.52
RCW), and Water Resources Act of 1971 (Chapter 90.54 RCW) require the use of all known, available.
and reasonable technologies (AKARTs) for controlling discharges to groundwater.
- Ambient concentrations of toxic air contaminants in the Puget Sound region are regulated by the
Puget Sound Air Pollution Control Agency (PSAPCA) pursuant to the State of Washington Clean Air Act
(Chapter 70.94 RCW) and 1r11>lementation of Regulations for Air Contaminant Sources (Chapter 173-
403 WAC).
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:.
The Best Available Control Technology (BACT) will be required for sources of toxic air
contaminants to minimize emissions. The ambient 1fT1)8d of emissions of toxic air
contaminants from new sources will be evakJated against Acceptable Source lrt1)8d
Levels (ASILs) adopted by PSAPCA. Toxic air contamlnarts are those air contaminants
listed in Appendix A of PSAPCA Regulation III or 8sted in Subpart 0, 40 CFR 372.
The ASIL for TCE is 0.8 uglm' and the ASIL for DCE is 2630.7 uglms.
Location-SpecifIC
Groundwater extractionltreatment activities will meet the following location-specific ARARs:
- State of Washington Hazardous Waste Management Ad (Chapter 70.1050 RCW) requirements for
dangerous waste and extremely hazardous waste as codifted In Chapter 173-303 WAC.
- State of Washington Hazardous Waste Cleanup-Model Toxies Control Ad (Chapter 70.1050 RCW)
requirements for the identification, investigation, and clean up of hazardous waste sites are being
developed in two phases. Phase I, which defines the administrative process for identifying,
investigating, and cleaning up hazardous waste sites, is applicable. All cleanup actions shall use
permanent solutions to the maximum extent practicable.
2. Information To-Be-Considered (TBC)
The following mcs will be used as guidelines when implementing the selected remedy:
- A screening evaluation of any source may be performed in accordance with PSAPCA's Guidelines for
Evaluating Sources of Toxic Air Contaminants (adopted August 9, 1990) to determine if the toxic air
contaminant emissions from the source would result in the exceedance of an ASIL contained in
Appendix A of PSAPCA Regulation III.
- OSWER Directive #9355.4-02 entitled .Interim Guidance on Establishing Soil Lead Cleanup Levels at
Superfund Sites., dated Septerrber 7, 1989 sets forth an interim soil deanup level lor total lead at 500
to 1000 mglkg.
,
- Memorandum re: .Cleanup Level for Lead in Groundwater: from H. Longest, OERR and B. Diamond,
OWPE to P. Tobin, Region IV Waste Management Division recommends a final cleanup level for lead
in groundwater usable for drinking water which will meet the CERCLA requirement 01 protectiveness of
human health and the environment.
C. Cost Effectiveness
The selected remedy is cost~ffective because it has been determined to provide overall effectiveness
proportionate to its costs and duration for remediation of the contaminated groundwater. Although the
30-year present worth of $9,068,000 for the selected remedy Is higher than Alternative 2, the benefrts
of an additional extractionltreatment system near the areas of highest groundwater contamination
include: 1) a 2o-year decrease in potential exposure duration due to contaminated groundwater and air
emissions; and 2) a reduction in the lateral and vertical migration of the contaminant plume both
downgradient of the Logistics Center and near the areas of highest groundwater contamination.
O. Use 01 Permanent Solutions and Alternative Treatment Technologies or Resource Recovery
Technologies to the Maximum Extent Pradk:able
The Army, the State of Washington, and EPA have determined that the selected remedy represents the
maximum extent to which pennanent solutions and treatment technologies can be used in a cost-
effective manner for the Logistics Center site. The risk from the groundwater contamination is
permanently reduced through treatment to acceptable exposure levels without transferring the risk to
another media (e.g., air). The selected remedy provides the best balance 01 tradeoffs in terms 01 Iong-
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term effectiveness and penn&nence; reduction In toxicity, mobility, or volume achieved through treatment,
short-term effectiveness; In1*Hnentabftlty; and cost.
Although both groundwater extraction and treatment remedial alternatives are protective of ruman heatth
and the envfronment, cof11)ly with ARARs, and win achieve reduction of risks, there is a SignifJCanl
difference In the time required to achieve remediation goals. Alternative 2 requires approximately 50
years to remediate the groundwater, whereas. Alternative 3 requires approximately 30 years.
E. Preference for Treatment as Principal Element
By treating the VOC~ntaminated groundwater in on-site treatment facilities, the seleded remedy
addresses the principal threat of future Ingestionlinhalation of contaminated groundwater posed by the
Logistics Center site through the use of treatment technologies. Therefore. the statutory preference for
remedies that employ treatment as a principal element is achieved.
"
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RESPONSIVENESS SUMMARY
FORT LEWIS LOGISTICS CENTER
The public comment period was held from June 5 - July 19. 1990. No written comments were received.
The Arrrry held a public meeting in TilliaJm on June 28, 1990 to explain the proposed plan and solicit
public comments. Attached is the portion of the transcript that covered tt1e public comment period held
OJring the public meeting. This summary is a response to questions raised during the public meeting.
,. Is the contaminant a carcinogen? What kind of cancer does It cause?
The primary contaminants found were trichloroethylene (TCE) and cis 1,2 - dichloroethylene (DCE). The
United States Environmental Protection AtJency (EPA) has dassified TCE as a probable human
carcinogen, which means it has been shown to cause cancer in animal species. However, evidence
from epidemiological studies is inadequate to condude whether TCE does or does not cause cancer
in humans. In mouse and rat studies, long-term inhalation exposure has caused lung, liver, and
testicular tumors, as well as, leukemia. Long term ingestion exposure has produced liver and kidney
tumors.
The EPA has not determined whether DCE can cause cancer in humans or animals since studies to
make this determination have not been conducted. However, adverse effects to the liver and kidney
have been observed in rat studies.
2. How fast Is the groundwater moving?
The range of groundwater velocity (speed of movement) in the shallow aquifer beneath the Logistics
Center varies with the permeability of the various parts of the aquifer. Groundwater movement was
measured in monitoring wells at the Logistics Center betwe€n 0.03 and 26 feet per day, with an
average velocity of 1.5 feet per day.
3. How much Is the contamination expanding?
The movement of TCE in sand and gravel aquifers with low organic carbon contents, such as aquifers
beneath the Logistics Center, is approximately one-half the average groundwater velocity of 1.5 feet per
day. Consequently, contamination movement would be approximately 0.75 feet per day. Also, TCE
concentration further decreases approximately one-half of 0.75 for every mile the plume moves because
of dispersion (the lateral spread of contaminants as they move with the groundwater) and volatilization
(evaporation) into gas.
4. What Is the expected date that It will hit and contaminate American Lake?
The Army sampled American Lake as part of the Logistics Center investigation. The sampling showed
that there are low levels of TCE and DeE in the lake, but the levels do not exceed drinking water
standards. The Army will conti~e to sample American Lake as part of a long term monitoring program.
5. Could the movement be Isolated and cut off so that It does not hit and contaminate
American Lake?
The groundwater alternative that has been selected consists of a series of wells within and near the
Logistics Center. These wells together with the treatment system should stop the plume from moving
towards American Lake. As mentioned in question 4, the Arrrry has not found elevated levels of
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PUBLIC MEETING ON PROPOSED CLEANUP PLAN
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PUBLIC COMMENT SESSION
2
MR. CAGLE:
What I'd like to ask is, if you
3
have comments on the plan, on the process, on the
4
proolem, if you would like to stand up and talk about
them publicly, would yo~ please state your name and
5
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your address for the record so that we can get a
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response back to you.
8
If you don't ~ant to stand, you can put your
9
question or your comment on the index cards.
Again,
please put your name and address on it so we can work
it for the record and get back to you with a
response.
Do we have any public comments at this point?
That's why we are here.
DR. RYDBOM:
What is the basic hazard, that
we are facing as far as this material is concerned,
health-wise?
MR. CAGLE:
All right, sir, your name and
address 00 that?
DR. RYDBOM:
I'm Dr. Rydbom, 8909 Thorne
Lane.
MR. CAGLE:
Do we need to address any of
these at this point?
MS. DURBIN:
I don't really know what --
Other than --
SA YSIDE REPORTERS
(c. Rentel and Associates)
4041 Ruston Way, Suite 1-0
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PUBLIC MEETING ON PROPOSED CLEANUP PLAN
Public Comment Session
6-28-90
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MR. LIVERMAN:
~ell,
sir,
were you thinking
perhaps that water or soil --
DR. RYDBOM:
.Is it a carcinogen?
MR. LIVERMAN:
-- or what one's
susceptibility might be(
TCE is a known carcinogen, a probable
carcinogen.
DR. RYDB0t\:
What kind of cancer does it
cause; any idea?
MR. LIVERMAN:
I'm not sure.
DR. RYDBOM:
Well, I was just wondering if
I got mine from the water.
MR. LIVERMAN:
I'll pass on that.
MS. DURBIN:
We'll definitely address it,
though.
I will definitely put that in a written
response.
I'll find out for you.
DR. RYDBOM:
Can you do that?
MS. DURBIN:
Yes.
I'm not sure.
MR. CAGLE:
All right,
sir.
Any other comments about the plan, about the
problems, about the proposals?
MS. DURBIN:
And also if anybody that asked
questions in the informal portion, if you'd like to
state your name and phone number and address for the
record, we can get a response back to you.
If you
SA YSIDE REPORTERS
(C. Rentel and Associates)
4041 Ruston Way, Suite 1-0
Tacoma. Washington 98402
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wanted something additional or whatever, we could do
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that too.
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THE AUDIENCE:
(No response.)
4
MR. CAGLE:
No comments.
Keep it open for a
5
few minutes.
6
MS. DURBIN:
And again, any written comments
7
that you have, if you could put them on the front
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table, we could coJlect them there.
Also, the "Public Comment Period" does continue.
It will continue to be open until the 19th of July
and we can take your public comments at any time.
UNIDENTIFIED SPEAKER:
That can be mailed to
this address that you have here?
MS. DURBIN:
Exactly.
That's exactly right.
"
MR. CAGLE:
. And you don't have to confine
it to the size of an index card either.
MS. DURBIN:
No , no .
And any comment that
you make can be not only on our Proposed Cleanup
Plan, but it can also be on the whole investigati~n
that we did.
Any comments that you'd like to make on
it, please do.
MR. CAGLE:
Are there any thoughts that you
have of areas that might not have been considered in
the review process?
'fes, sir.
SA YSIDE REPORTERS
(C. Rentel and Associates)
4041 Ruston Way. Suite 1-0
T acoma, Washington 98402
Tacoma: 752-2101 Seattle: 838-6001
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PUBLIC MEETING ON PROPOSED CLEANUP PLAN
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6-28-90
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MR. MCKINNON:
Are you interested in whether
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we are interested -- whether we want the 50-year plan
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or the 30-year plan, or what sort of plan?
4
MR. CAGLE:
That could be part of your
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comment, yes, sir.
6
MR. MCKINNON:
My name is Cameron McKinnon,
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I live at 14 Thornewood Lane Southwest.
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I would be ve!y much in favor of the 30-year
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plan rather than the 50-year plari.
Let's get this
thing cleaned up.
Also, at the same time I'm wondering, just how
fast are these fluids moving?
How much is this
expanding?
How much time do we have to clean it up?
MR. LIVERMAN:
Well, the groundwater beneath
the Logistics Center is estimated to travel perhaps
--
one and a half feet per day.
That estimate ranges to
as much as seven feet per day.
Of course, that would be influenced by seasonal
variations, such as during periods of high rainfall,
it is entirely possible that it may run more rapidly
than it would otherwise during the drought season.
50 with that thought in mind of perhaps one and
a half feet per day, that would give you some
estimate as to how long it would take to travel.
MR. MCKINNON:
The distance that you would
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(C. Rentel and Associates)
4041 Ruston Way, Suite 1-0
Tacoma. Washington 98402
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PUBLIC MEETING ON PROPOSED CLEANUP PLAN
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indicate on there, the northern part of Ti11icum, is .
expanding, we'll say a foot and a half to seven foot
a day, and heading towards American Lake?
MR. LIVERMAN:
Well, sir, it is not
5
expanding perhaps in the sense of -- It is moving
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towards the lake.
And that's not to necessarily
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suggest that is expanding horizontally beyond the
boundaries that ar~ indicated on the map here.
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MR. MCKINNON:
What is the expected date
that it will hit and contaminate the lake?
MS. DURBIN:
I'm not -- I can't really
answer
that at this time, but it is definitely
something that we can address in the response.
MR. MCKINNON:
Is this something that could
,.
be isolated and cut off and treatment started over
there, or is all of your treatment going to be on the
base?
MS. DURBIN:
One of the things that we are
trying to do, as far as looking at treatment, is we
try to put the well closest to the source area, the
source area being the East Gate Disposal Yard and the
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Logistics Center itself.
It is more effective in
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that particular area, and that is one of the reasons
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we looked at that.
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MR. MCKINNON:
But would the source area,
SA YSIDE REPORTERS
(C. Rentel and Associates)
4041 Ruston Way, Suite 1-0
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PUBLIC MEETING ON PROPOSED CLEANUP PLAN
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6-28-90
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which is far away from the tip in the northern part
of Tillicum there draw that contaminants back?
MS. DURBIN:
Probably not.
MR. MCKINNON:
They'd stay there forever
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then?
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MR. HANNA:
No.
No, sir.
It will continue
7
to move toward forward.
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The way in whJch the plan is now conceptually
9
presented is to intercept the groundwater at two
locations, that being in close proximity to the East
Gate Disposal Yard, and also in close proximity to
1-5.
That is not to suggest that two wells here or
four wells is the answer.
There may be CQnsiderably
more.
--
"
The intent is to extract the groundwater to
treat it, and then to allow it to passively recharge
back into the groundwater.
In the instance of the East Gate Disposal Yard,
at a configuration yet to be designed, it would have
the effect of not only flushing the soil, in the
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sense that you would flush contaminates that mayor
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may not be present in the soil into the groundwater,
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to the extent that they would be intercepted at the
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extraction wells and then processed.
8A YSIDE REPORTERS
(C. Rentel and Associates)
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PUBLIC MEETING ON PROPOSED CLEANUP PLAN
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At the 1-5 location, the intent is to have a
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series of extraction wells to intercept the plume and
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to treat the water, and then at a location closer to
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1-5, allow it to passively recharge the groundwater,
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and in doing so, push tbe plume, if you will.
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But the plume should not remain stagnant between
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1-5 and American Lake.
It will continue to move.
8
And as a result of, having the clean groundwater
recharge -- or rather, having th~ water recharge the
9
contaminated groundwater, that should not only dilute
the contamination, which in conjunction with natural
rainfall and a percolation of that nature, it
should remediate the groundwater to an acceptable
level, that being MCL.
,.
MR. MCKINNON:
Thank-you.
MS. DURBIN:
In addition, the type of
chemical that we are dealing with is TCE, and it
wants to vaporize, it wants to go into the air.
So when it goes toward American Lake, and when
it gets there, that" is what it tends to do.
And that
is one of the reasons that we think we're not
violating the levels in American Lake.
So, yes, the plume is moving and it will clean.
It will flush it out.
MR. CAGLE:
Any other comments.
SA YSIDE REPORTERS
(c. Rentel and Associates)
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PUBLIC MEETING ON PROPOSED CLEANUP PLAN
Public Con~ent Session
post-Meeting Comment
'i.J
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THE AUDIENCE:
(No response.)
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MR. CAGLE:
I thank you.
I think this will
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conclude the session for ~ow.
We'll be around for a
4
few minutes to answer individual questions.
5
I'm sure that if YQu have any comments, you can
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go ahead and fill them out on the card and bring them
7
up here, or send them to Kris at the address on the
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fact sheet.
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MS. SCHNEIDER:
There are also copies, a
summary of the slide show that was given outside and
will serve to refresh your memory of what you saw.
MS. DURBIN:
Thank you very much for your
comments.
MR. CAGLE:
And thank you all very much for
coming out tonight.
We appreciate your interest.
,.
(Meeting concluded at 8:25 p.m.)
(Comment made after meeting and put on
record at request of Ms. Durbin:)
MS. MILLER:
Esther M. Miller, 14511
Woodbrook Drive Southwest, Ti11ieum 98439.
The question was, what happens to the fumes or
whatever that comes up into the air?
What does it do
to us in our breathing?
MS. DURBIN:
What I said is, it will
immediately break down into the chemicals that that
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post-Meeting Comment
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is made up of, the chlorine, carbon dioxide, and
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water, or in a few days the sunlight will help break
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it down.
- - )
( Hozord:;.
\ \nforma
US EP .
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END OF ADDITIONAL,ON-RECORD COMMENT
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SA YSIDE REPORTERS
(C. Rente! and Associates)
4041 Ruston Way, Suite 1-0
T acoma, Washington 98402
Tacoma: 752-2101 Seattle: 838-6001
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