PROPOSED PLAN
FOR AN INTERIM CLEANUP ACTION
AT THE HAMILTON ROAD IMPACTED AREA:
OPERABLE UNIT 1 OF THE
HAMILTON/LABREE ROADS GROUNDWATER
CONTAMINATION SUPERFUND SITE
CHEHALIS, WASHINGTON
PREPARED BY:
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION 10 SEATTLE, WA
SEPTEMBER 2012
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CONTENTS
1.0 PURPOSE OF EPA'S PROPOSED PLAN 1-1
1.1 CLEANING UP THE SITE IN PHASES 1-1
1.2 THE INTERIM CLEANUP PREFERRED ALTERNATIVE 1-2
1.3 PUBLIC INVOLVEMENT 1-3
1.4 PROPOSED PLAN ORGANIZATION 1-4
2.0 SITE BACKGROUND 2-1
2.1 THE HRIA (OU1) 2-1
2.2 OPERABLE UNIT 2 (OU2) 2-2
2.2.1 BREEN PROPERTY 2-2
2.2.2 THURMAN BERWICK CREEK AREA 2-3
2.2.3 DOWNGRADIENT AREAS WEST OF LABREE ROAD 2-3
2.3 HISTORY OF SITE-WIDE INVESTIGATIONS 2-4
3.0 SITE CHARACTERISTICS 3-1
3.1 PHYSICAL CHARACTERISTICS 3-1
3.1.1 CLIMATE 3-1
3.1.2 TOPOGRAPHY AND DRAINAGE 3-1
3.1.3 GEOLOGY 3-1
3.1.4 GROUNDWATER 3-2
3.1.5 SURFACE WATER 3-2
3.1.6 LAND AND RESOURCE USES 3-3
3.1.7 ECOLOGY 3-4
3.2 NATURE AND EXTENT OF CONTAMINATION 3-4
3.2.1 NATURE OF CONTAMINANTS 3-4
3.2.2 EXTENT OF CONTAMINATION 3-4
3.2.3 ESTIMATES OF PCE MASS, VOLUME, AND SURFACE AREA WITHIN THE
HRIA 3-8
3.3 PRELIMINARY CONCEPTUAL SITE MODEL 3-8
4.0 SCOPE AND ROLE OF PROPOSED INTERIM CLEANUP ACTION 4-1
5.0 SUMMARY OF SITE RISKS 5-1
5.1 HUMAN HEALTH RISKS 5-1
5.2 ECOLOGICAL RISKS 5-2
5.3 BASIS FOR ACTION 5-3
6.0 REMEDIAL ACTION OBJECTIVES 6-1
6.1 HRIA RAOS 6-1
6.2 PRELIMINARY REMEDIATION GOALS 6-2
6.2.1 KEY FACTORS FOR SETTING HRIA INTERIM ACTION PRGS 6-2
6.2.2 HRIA PRGS FOR EACH REMEDIATION TARGET ZONE 6-3
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7.0 SUMMARY OF INTERIM CLEANUP ALTERNATIVES 7-1
7.1 COMMON ELEMENTS ACROSS ALTERNATIVES 7-1
7.1.1 RE-ROUTE BERWICK CREEK 7-1
7.1.2 INSTITUTIONAL CONTROLS 7-2
7.1.3 MONITORING 7-2
7.1.4 FIVE-YEAR REVIEWS 7-2
7.1.5 ARARS WAIVER 7-3
7.2 UNIQUE FEATURES OF EACH CTS ALTERNATIVE 7-3
7.2.1 CTS-1 NO ACTION 7-3
7.2.2 CTS 2 (EPA'S PREFERRED ALTERNATIVE) 7-4
7.2.3 C I S 3 7-6
8.0 EVALUATION OF CTS ALTERNATIVES 8-1
8.1 THE NINE CRITERIA 8-1
8.1.1 THRESHOLD CRITERIA 8-1
8.1.2 BALANCING CRITERIA 8-2
8.1.3 MODIFYING CRITERIA 8-2
8.2 COMPARATIVE ANALYSIS OF CTS ALTERNATIVES 8-2
8.2.1 OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT8-3
8.2.3 COMPLIANCE WITH ARARS 8-3
8.2.4 LONG-TERM EFFECTIVENESS AND PERMANENCE 8-4
8.2.5 REDUCTION OF TOXICITY, MOBILITY, OR VOLUME THROUGH
TREATMENT 8-4
8.2.6 SHORT-TERM EFFECTIVENESS 8-4
8.2.7 IMPLEMENTABILITY 8-6
8.2.8 COST 8-7
9.0 PREFERRED ALTERNATIVE FOR OU1 9-1
9.1 A PHASED APPROACH 9-1
9.2 THE PREFERRED ALTERNATIVE 9-1
9.3 BENEFITS OF PROPOSED PREFERRED ALTERNATIVE 9-2
10.0 COMMUNITY PARTICIPATION 10-1
11.0 LIST OF ACRONYMS USED IN PROPOSED PLAN 11-1
12.0 GLOSSARY 12-1
13.0 REFERENCES 13-1
WRITTEN COMMENTS
EXHIBITS
6-1 PRGs for PCE by Target Zone for Each RAO
TABLES
3-1 Contaminant Mass, Volume, and Surface Area
6-1 Chemical-Specific ARARs/TBCs
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6-2 Location-Specific ARARs/TBCs
6-3 Action-Specific ARARs/TBCs
6-4 Mass and Volume of PCE in HRIA Remediation Target Zones
8-1 Criteria Priorities
8-2 Summary of Comparative Analysis of Comprehensive Technology Scenarios
FIGURES
1-1 Site Location Map
1-2 Overview of Hamilton/Labree Superfund Site
3-1 Regional Topography and Drainage
3-2 Historical Sampling Locations HRIA
3-3 HRIA Hot Spots Site Map
3-4 Berwick Creek Bed, Bank, and Surface Water Sampling Locations
3-5 Hamilton/Labree Upper Zone of Shallow Aquifer PCE Isoconcentration Plot -
Historical
3-6 Hamilton/Labree Lower Zone of Shallow Aquifer PCE Isoconcentration Plot -
Historical
3-7 Ambient Air and Soil Vapor Sample Locations
3-8 Conceptual Model
6-1 Creek Bed Sediment/Shallow Soil and Subsurface Soil PCE Remediation Target
Zones
6-2 Proposed Remediation Target Zones
7-1 Comprehensive Technology Scenario (CTS) 2 Conceptual Remedial
Configuration
7-2 Comprehensive Technology Scenario (CTS) 3 Conceptual Remedial
Configuration
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1.0 PURPOSE OF EPA's PROPOSED PLAN
The U.S. Environmental Protection Agency (EPA) is seeking input from the public on a cleanup
proposal for a part of the Hamilton/Labree Roads Groundwater Superfund Site (Site). The part
of the Site to be addressed by this proposal is called the Hamilton Road Impacted Area
(HRIA). This document, the Proposed Plan, describes the cleanup alternatives that EPA
considered to address contamination within the HRIA, EPA's preferred cleanup alternative, and
the rationale for this preference. EPA will select a cleanup alternative for the HRIA after
considering all comments received. The selection will be documented in an Interim Record of
Decision (Interim ROD). The cleanup will be an interim action because EPA will propose and
select other cleanups for the Site after the HRIA cleanup action starts and additional site-wide
data is collected and evaluated.
This Proposed Plan summarizes information found in greater detail in the draft site-wide
Remedial Investigation (RI) report (CDM Smith 201 la), the draft site-wide Baseline Risk
Assessment (BLRA) report (CDM Smith 201 lb), the draft HRIA Feasibility Study (FS) report
(CDM Smith 2012), and other supporting documents in the Administrative Record. The
Administrative Record contains the documents that form the basis for the selection of EPA's
preferred cleanup alternative for the HRIA.
1.1 CLEANING UP THE SITE IN PHASES
The Site is about two miles south of the City of Chehalis, Washington, near the intersection of
North Hamilton Road and Labree Road, west of Interstate 5 (1-5) (Figure 1-1). The Site has been
divided into two areas, called Operable Units, to facilitate the identification and cleanup of
hazardous substances: Operable Unit 1 (OU1) also known as the HRIA; and, Operable Unit 2
(OU2) which includes all other areas outside of OU1 (the HRIA) where hazardous substances
have come to be located including the Breen Property, the Thurman Berwick Creek Area, and
the area west and northwest of Labree Road (Figure 1-2). Hazardous substances have been
released in both OUs contaminating creek sediment, soil and groundwater.
EPA intends to address contamination at the Site through a phased approach beginning with an
interim cleanup action in the HRIA. A phased approach to site cleanup is the most appropriate
when site characterization is not yet complete or when site data are not sufficient to develop
and evaluate cleanup alternatives to address risks posed by the entire site or to determine long-
term objectives for the entire site (e.g., restoring groundwater to safe drinking water levels).
There appears to be other contamination sources at the Site outside of the HRIA; however,
additional site-wide data collection and evaluation is needed to develop, select and implement
other cleanup action(s) for the Site that will achieve long-term protection of human health and
the environment. The proposed interim cleanup action for the HRIA presented in this Proposed
Plan is necessary to address the known sources of contamination to sediment, soil and
groundwater within the HRIA and the most immediate risks posed by these sources, and to
minimize further migration of contaminated groundwater from HRIA to downgradient areas.
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1.2 THE INTERIM CLEANUP PREFERRED ALTERNATIVE
The HRIA is located at the most upgradient part of the Site and is about 10 acres in size
(Figure 1-2). The HRIA is crossed from northwest to southeast by North Hamilton Road and
Berwick Creek. The primary contaminant of concern (COCs) at the HRIA, tetrachloroethene
or PCE, appears to be the result of a spill or direct release of liquid PCE into Berwick Creek
from an unknown entity. PCE is a chemical used for dry cleaning, metal degreasing and other
industrial processes. PCE has contaminated creek bed sediment and bank surface soil, subsurface
soil and groundwater based on the results of sampling.
EPA considered a number of cleanup alternatives to best address HRIA contamination. These are
discussed in detail in the draft FS report and summarized later in this Proposed Plan. As the lead
agency for this interim cleanup, EPA is proposing Comprehensive Technology Scenario (CTS)
Alternative #2 (Alternative CTS-2) as the Preferred Alternative. This alternative is summarized
below and includes the following components:
• Re-route Berwick Creek around areas of contamination.
•S Re-routing about 200 feet of Berwick Creek around the areas of contamination in the
HRIA will help protect wildlife, fish and other organisms that live in or visit the
creek channel from possible negative impacts caused by cleanup activities. The creek
will be re-routed to a location within the HRIA where it may remain permanently.
The creek channel (bed and banks) would be designed to meet requirements that
protect ecological inhabitants, e.g., less than 0.468 milligrams per kilogram [mg/kg]
PCE, based on EPA's benchmark for protection of organisms living in freshwater
sediments.
• Heat sediment and soil with PCE concentrations greater than 10 mg/kg.
•S Increasing the temperature by heating the sediment and soil would remove
contaminant mass and reduce PCE concentrations to 10 mg/kg.
• Excavate and dispose of remaining sediment and surface soil with PCE
concentrations greater than 10 mg/kg.
•S If heating of the sediment and surface soil is not successful in reducing PCE
contamination to 10 mg/kg, the sediment and surface soil will be excavated.
^ The excavated sediment and surface soil would be consolidated within the HRIA
and treated with a chemical, such as potassium permanganate if necessary to meet
disposal requirements or they may be treated at an off-site, licensed disposal
facility.
• Add organic materials to groundwater with PCE concentrations greater than
4,000 micrograms per liter (jig/L).
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¦S Injecting organic material such as emulsified vegetable oil into groundwater with
PCE concentrations greater than 4,000 |ig/L would enhance the biological
breakdown of PCE and reduce the migration of PCE from the HRIA to other areas
of the Site by 90%.
• Institutional controls
S Institutional controls or ICs will be implemented during and after the interim
cleanup action. ICs are non-engineered instruments, such as legal restrictions,
covenants or easements on property, and governmental and/or administrative
controls that as part of this interim action would be used to help prevent or
minimize the potential for human exposure to hazardous substances, pollutants or
contaminants. The objectives of the ICs for the HRIA include preventing the use
of groundwater for drinking water and requiring workers to wear protective gear.
• Monitoring
•S Sampling of surface water, sediment, soil, groundwater, and air sampling will be
performed during and after cleanup in order to ensure protection of humans and
the environment, and to determine the effectiveness of the interim cleanup action.
1.3 PUBLIC INVOLVEMENT
This Proposed Plan is being issued as part of the public participation requirement under Section
117(a) of the Comprehensive Environmental Response, Compensation and Liability Act
(CERCLA or Superfund), as amended, and the National Contingency Plan (NCP). This
document is issued by EPA, the lead agency for site activities, with the support of the
Washington State Department of Ecology (Ecology).
This Proposed Plan presents EPA's rationale for the preferred interim cleanup action alternative
for the HRIA, and also provides a summary of the other remedial alternatives evaluated as part
of the selection process. EPA will select the interim cleanup action for the HRIA after reviewing
and considering all information and comments submitted during the public comment period.
EPA, in consultation with Ecology, may modify the preferred alternative or select another
cleanup alternative presented in this Proposed Plan based on new information or on comments.
Therefore, we encourage all interested parties to review and comment on all of the alternatives
presented in this Proposed Plan. You can find documents referred to in this Proposed Plan in the
Administrative Record, which is available for public review at the following locations:
Vernetta Smith , Chehalis Timberland Library
400 N. Market Blvd.
Chehalis, WA 98532-0419
(360) 748-3301 (Callfor hours)
EPA Region 10
Superfund Records Center
1200 Sixth Avenue, Ste. 900 (ECL-076)
Seattle, WA98101
(206) 553-4494 (Callfor an appointment)
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Your Comments: EPA welcomes and encourages your comments on this Proposed Plan during
the comment period from September 28, 2012 through November 9, 2012 and on the day of the
public meeting on October 23, 2012 at the following location:
Veterans Memorial Museum
100 SW Veterans Way
Chehalis, WA 98532
(360) 740-8875
http://www.veteranmuseum.org
An Open House on the Proposed Plan will take place before the public meeting from 5:00PM to
6:00PM where EPA staff will be available to answer your questions. The public meeting is from
6:30 PM to 9:00 PM where there will be a short presentation after which formal oral and written
comments will be accepted. The Interim ROD will also include a Responsiveness Summary,
which will contain the responses to the comments received during the Proposed Plan public
comment period.
Written comments may be submitted either at the public meeting or mailed to:
Ms. Tamara Langton
US EPA Region 10
1200 Sixth Ave, Suite 900
Office of Environmental Cleanup, ECL-113
Seattle, WA98101
(T) 206-553-2709
(F) 206-553-0124
langton.tamara@epa.gov (For emailed comments, please put "HRIA Proposed Plan" in the
subject line.)
1.4 PROPOSED PLAN ORGANIZATION
Following this introduction, the Proposed Plan contains the following major sections:
1)
Introduction
2)
Site Background
3)
Site Characteristics
4)
Scope and Role of the Proposed Cleanup Action Plan
5)
Summary of Site Risks
6)
Remedial Action Objectives
7)
Summary of CTS Alternatives for the HRIA
8)
Evaluation of CTS Alternatives
9)
Preferred Alternative
10)
Community Participation
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2.0 SITE BACKGROUND
This section describes the areas of the Hamilton/Labree Site by Operable Unit, and provides a
history of studies (investigations) that have been conducted across the Site.
2.1 l lll HRIA (OU1)
The HRIA (OU1) is located at the most upgradient portion of the Site. It is about 10 acres in size
(Figure 1-2). It is crossed from northwest to southeast by North Hamilton Road and Berwick
Creek. North Hamilton Road was built in 1974 by the Washington State Department of
Transportation.
The portion of the HRIA located between North Hamilton Road and 1-5 consists of grassy open
land that includes Berwick Creek (which flows northwest), overhead power lines, and a wire
field fence that prevents access to 1-5. This portion of the HRIA is entirely within the rights-of-
way of the two paved roads under jurisdiction of the Washington State Department of
Transportation. Two unnamed ditches pass underneath 1-5 and discharge to Berwick Creek
within the HRIA. The portion of the HRIA west of North Hamilton Road includes the area
referred to as the former United Rentals Property. The property is level, with mixed gravel,
asphalt, and concrete surfaces, and contains two buildings: the main building and the paint shop.
An easement containing buried utilities and a storm water conveyance system is located between
the former United Rentals Property and North Hamilton Road.
The former United Rentals Property has changed occupants and ownership numerous times since
the late 1980s. In 1988, Carl Watson purchased this property, which at the time was a swampy
hayfield containing a few old car bodies and empty barrels. The property was graded flat and a
layer of fly ash and about 90 truckloads of rocks were imported to build up the footprint for the
subsequent buildings. The main building was built during the winter of 1989/1990.
Beginning in June 1990, a transmission rebuilding company operated at the property under the
name Westside Trucking Company. In 1991, Westside Trucking Company changed its name to
Gear Box, Inc. and operated under that name until October 1992, when the business closed. The
property was sold on May 20, 1993, to E.G.W. Machinery, Inc., the owner of High Reach,
Incorporated. High Reach, Inc. rented and serviced specialized aerial construction equipment. A
second building, known as the paint shop, was built on this property in 1993.
In 1998, High Reach, Inc. was purchased by United Rentals Northwest, Inc. At this location,
United Rentals ran a rental and repair service for a variety of construction equipment. United
Rentals also operated a small business that painted heavy equipment until 2009, after which the
property was vacated. In April 2012, the property was sold to Visitrade, Inc. and in June 2012,
Visitrade leased the property to a building materials store named Builder's Surplus Northwest.
The portion of the HRIA west of North Hamilton Road and south of the former United Rentals
Property includes a gravel access road and an open, steep-sided drainage ditch. Both are on a
narrow stretch of property that runs from North Hamilton Road to a larger, undeveloped area just
southwest of the former United Rentals Property. Only a small section of this undeveloped land
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is within the HRIA. The access road, drainage ditch and undeveloped land was originally owned
by Warren Willard. In 2007 Mr. Willard sold this property to the McGill Investment Company.
The property south of the access road and drainage ditch area includes a level area covered with
gravel and a commercial warehouse next to and south of the gravel area. Up to four feet of
material, mainly boulders, was used to fill in and level the property before development. The
developed property was originally owned by Reginald and Kimberly Hamilton who ran a
company named Hamilton Rocking and Contracting Company from the early 1990's to 1997.
They shared the property with the Smith Tractor Company until 1997, when Smith Tractor
became the sole tenant. The Smith Tractor Company rented and sold trucks and construction
equipment, along with parts for this type of equipment. The company added a wash rack that had
a concrete slab floor behind the building in about 1996 and used the gravel area to park tractor-
trailers.
The property has been sold twice since it was developed and has had a number of tenants. The
current owner is Hamilton Road Adventures who leases the property to Emerald Recreational
Vehicles (Emerald RV). Emerald RV buys, sells, and rents RVs and related equipment to the
public.
2.2 OPERABLE UNIT 2 (OU2)
Operable Unit 2 (OU2) includes all other areas outside of OU1 (the HRIA) where hazardous
substances have come to be located including the Breen Property, the Thurman Berwick Creek
Area, and the area west and northwest of Labree Road
2.2.1 Breen Property
The Breen Property (part of OU2), is located northwest of the HRIA and covers about 11 acres
(Figure 1-2). The Breen Property was purchased by Sterling (Bud) Breen, Sr., President of S.C.
Breen Construction Company, in the early 1950s. The property was used for agricultural
purposes before it was developed by S.C. Breen Construction Company. By the early 1970s,
most of the Breen Property had been cleared of vegetation.
The Breen Property, originally one tax parcel, was subdivided in 1992. It now consists of two
separate tax parcels, currently owned by two different entities.1 The western portion of the Breen
Property is still owned by the S.C. Breen Construction Company and is made up of about 5.75
acres, which includes several wood-framed, steel-clad buildings with concrete floors, and open
areas between the buildings used for storing trucks and other heavy equipment and construction
materials.
One of these buildings (currently referred to as Building C) was built in about 1960 on the
southwest part of the parcel. This building, referred to as the "Old Shop" served as the S.C.
Breen Construction Company's main office and truck maintenance shop until the early 1990s.
1 For purposes of this Proposed Plan and earlier site reports, the term "Breen Property" refers to both tax parcels.
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Since then, Building C has been leased to a number of other companies including the Roy F.
Weston Company.
North of Building C was the Breen Surplus store which began operating in the mid-1960s. Breen
Surplus bought and sold a variety of equipment, tools, paints, thinners and solvents. This store
and building no longer exist.
Southeast of Building C is a 24' x 28' cement slab that was used as a heavy equipment wash-
down pad. Based on a review of aerial photographs, this wash-down pad appears to have been
constructed between 1966 and 1969. Runoff and sediment from the cleaning operation was
collected in a pit, about 5 feet deep, excavated next to the concrete pad. This collection pit has
never been located; the wash-down pad is no longer being used.
In 1972, what is currently referred to as Building A was built on the north end of the Breen
Property. In about 1983, another building (Building B) was constructed on the Breen Property
southeast of Building A. In 1995, Bulldog Trailers began operating on this property using both
Building A and Building B. Bulldog Trailers makes general-purpose utility trailers and sells
them.
Bulldog Trailers temporarily vacated Building B in 1999, when a large number of drums
containing PCE and solvents were removed from under a section of the building (see Section 2.2
[Regulatory Activities] for more information on this cleanup action). Bulldog Trailers currently
operates out of both Building A and Building B.
The S.C. Breen Construction Company sold the eastern portion of its property to the Chehalis
Livestock Market in 1992 (Farallon 2003). The parcel is about 4.92 acres in size and contains a
large building (Livestock Auction Building) that houses an arena, a cafe and offices, plus outside
livestock pens. This parcel is primarily used as a cattle auction facility. The livestock market
opened around 1960. A smaller wood-framed building with a dirt floor is located along the
southern boundary (Livestock Shed). This building is mostly used to hold calves and other small
livestock before auction. The remainder of this parcel is an unpaved parking area. Berwick Creek
runs along the southern property boundary of this parcel.
2.2.2 Thurman Berwick Creek Area
The Thurman Berwick Creek Area (part of OU2) is located in the southeast corner of the
intersection of North Hamilton Road and Labree Road, west and downgradient of the HRIA and
south of the Breen Property. The Thurman Berwick Creek Area is divided by Berwick Creek into
two portions: the northwest portion, which currently contains a residential structure built in 1930,
and the southeast portion, which is undeveloped land.
2.2.3 Downgradient Areas West of Labree Road
This portion of the Site (part of OU2) includes the remaining area within the PCE groundwater
plume footprint that is downgradient of the HRIA, the Breen Property, and the Thurman Berwick
Creek Area west of Labree Road (Figure 1-2). Most of the current land use in this area is
farmland, but residential and light commercial uses also occur.
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2.3 HISTORY OF SITE-WIDE INVESTIGATIONS
In 1993, a business along North Hamilton Road submitted a public water system application for
a commercial well. As part of the approval process, the business was required to perform water
quality testing, including a test for volatile organic compounds (VOCs). Test results indicated
PCE at 122 |ig/L in the water sample (the Federal and State drinking water maximum
contaminant level [MCL] for PCE is 5 (^g/L). The discovery of PCE in groundwater led the
Lewis County Department of Public Health (LCDPH) to request the Washington State
Department of Health (WDOH) to investigate groundwater in private and public supply wells in
the area (WDOH 1999).
In late 1993/early 1994, the WDOH sampled 18 private water-supply wells in the area. PCE was
detected in 6 of the 18 water-supply wells ranging from 3.3 [j,g/L to 2,165 [j,g/L (Washington
State Department of Ecology (Ecology) 1999a). In response to the findings, the LCDPH
informed affected well owners of the sampling results and advised them to obtain alternative
sources of drinking water (WDOH 1999). Ecology began supplying water to affected well
owners for drinking, cooking, and bathing. In 1996, WDOH re-sampled 5 of the 6 PCE-
contaminated water supply wells2 and found that concentrations had increased slightly from
those measured in 1993 and 1994 (PCE ranged from 5.75 |ig/L to 3,009 |ig/L).
In 1996, the LCDPH learned from a confidential source that drums containing solvents might
have been buried on the Breen Property. Ecology began an investigation that included a
geophysical survey by Geo-Recon International (Geo-Recon 1996) and a subsurface
investigation by Science Applications International Corporation (SAIC 1997). Between October
1997 and July 1998, Ecology sampled monitoring wells quarterly. Some of the monitored wells
were installed by SAIC and some were private water-supply wells. In spring 1998, Ecology
contracted Transglobal Environmental Geosciences (TEG) Northwest, Inc. to conduct an
additional subsurface investigation (Ecology 1999a). Based on results of these investigations
(mainly from groundwater sampling results) the drums were suspected to be buried under
Building B on the Breen Property.
In spring 1998, during the investigation by TEG for Ecology, another source of contamination
was found in the area between North Hamilton Road and 1-5 around Berwick Creek. This area is
now referred to as the HRIA. TEG advanced direct push (i.e., Strataprobe™) borings across the
HRIA and collected groundwater samples. The highest concentration of PCE (60,000 (J,g/L) was
detected in a boring advanced between Berwick Creek and North Hamilton Road about 40 feet
east of the former United Rentals property. PCE concentrations in groundwater sampled from
adjacent borings ranged from 57,000 [j,g/L to 22,000 (J,g/L.
In August 1999, the Breen's entered into an Agreed Order with Ecology to conduct an additional
investigation on the Breen Property. This investigation included a geophysical survey by
Northwest Geophysical Associates in August 1999 (GeoEngineers 2001, Appendix D) and
additional subsurface investigation by GeoEngineers, Inc. in August 1999 (GeoEngineers 2001).
Before conducting the geophysical survey in Building B, a part of the concrete floor was broken
2 One of the six wells was no longer in service.
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up and removed to eliminate the wire mesh reinforcing material within the floor that could have
interfered with the geophysical instruments. The concrete floor and offices at the north end of
Building B and the paint booth at the southern end of Building B were not removed. The
following geophysical survey identified an anomaly in the south central portion of Building B,
where the slab had been removed. This anomaly turned out to be a buried drum cache.
All of the drums appeared to contain water, as groundwater had seeped into the leaking drums, as
well as a black sludge-like material. The contents of two of the excavated drums were sampled
and analyzed. Based on laboratory results, the two drums contained a mixture of lubrication oil,
grease and solvents typically associated with painting and equipment degreasing activities. PCE
was detected in both drums above the MCL. . The other drums were assumed to have similar
results. A total of sixty-six 55-gallon drums, four 30-gallon drums, and several 1- to 5-gallon
containers, as well as 600 tons of PCE and petroleum-contaminated soil, were removed from
under Building B and taken to nearby treatment and disposal facilities. Groundwater recovered
from the excavation was treated using a granular activated carbon filter and then taken to the
City of Longview sewage treatment plant for disposal (GeoEngineers 2001).
On July 27, 2000, the Site was added to the EPA National Priorities List (NPL), and EPA took
over supplying bottled water to impacted residents.(EPA 2001a, EPA 2002a), Also in 2000, the
EPA Superfund Technical Assistance and Response Team (START) contractor, Ecology and
Environment, Inc. (E&E), began a phased removal assessment in the HRIA source area. Soil
borings, and new groundwater monitoring wells were installed, and subsurface soil and
groundwater samples were taken in and near the HRIA to evaluate the extent of impacts to
private water supply systems (E&E 2000, E&E 2001, E&E 2002). The removal assessments
resulted in a Time Critical Removal Action to expand the City of Chehalis municipal water-
supply system to 18 properties across the site (15 residential and 3 commercial) (EPA 2002b,
EPA 2002c, E&E 2003).
On October 31, 2001, an Administrative Order on Consent (AOC) was signed between EPA and
Breen (EPA 2001b). The AOC required the Breen's to conduct a site-wide Remedial
Investigation/Feasibility Study (RI/FS) within the Breen Property, the area downgradient of the
HRIA and cross gradient of the Breen Property (east of Labree Road), and the area downgradient
of the HRIA and the Breen Property (west of Labree Road). The Breen investigations were not to
include the PCE source area within the HRIA east of North Hamilton Road or at the former
United Rentals Property west of North Hamilton Road as these areas were being investigated by
EPA. EPA was to submit data collected during the HRIA investigations to Breen for inclusion
into site-wide RI and FS reports.
In accordance with the AOC, Breen (through their consultant, Farallon Consulting, L.L.C.
[Farallon]) began Phase I Investigations in 2002 (Farallon 2002). The overall objective of the
Phase I Investigation was to review existing Site data and identify data gaps to guide the
development of a site-wide RI/FS Work Plan. Phase I Remedial Investigation (RI) activities
were initiated in the Summer of 2003 under EPA oversight (Farallon 2003).
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In 2003, EPA contractor URS Group, Inc. (URS) began additional field investigations at the
HRIA to support completion of an Engineering Evaluation/Cost Analysis (EE/CA) report (URS
2004). The purpose of the EE/CA field investigation was to better define the extent of soil and
groundwater contamination, including defining the extent of dense non-aqueous phase liquid
(DNAPL) in the Berwick Creek bed and the shallow aquifer (see Section 3 for a description of
the shallow aquifer) as related to a potential spill or direct release into Berwick Creek. The
purpose of the EE/CA report was to evaluate data collected from previous investigations and
alternatives for cleaning up the HRIA source area, and for EPA to provide a preferred cleanup
alternative.
In early 2004, Breen Phase IRI activities were stopped prior to completion when EPA and Breen
began negotiating a cash-out settlement. Negotiations ended in 2007 without reaching an
agreement.
Also in 2004, EPA completed the EE/CA field investigations in the HRIA which revealed that
the source of contamination within the HRIA appears to be the result of a spill or direct release
of liquid PCE into Berwick Creek by an unknown entity no later than 1990, based on the
estimate of the plumes extent in 1993. The exact date of the spill/release is unknown.
Most of the PCE sank to the creek bottom where it pooled in low areas in the sediment and silt
layer. PCE then moved downward into the underlying soil and groundwater below the silt layer
where it continues to dissolve and move with the regional groundwater flow to downgradient
areas. The EE/CA's preferred cleanup alternative was to use a hydraulic containment technology
without removing the silt layer from under Berwick Creek in order to stabilize the contaminated
groundwater plume. The EE/CA report also recognized that over the long term, a more
aggressive technology needed to be used to further reduce PCE concentrations within the HRIA.
The EE/CA report envisioned that a more aggressive technology would be determined after a
site-wide RI/FS was completed (URS 2004).
In December 2004, EPA signed a time-critical removal action memorandum to build and operate
a pump and treat system which would stabilize the contaminated groundwater plume and prevent
further migration of PCE from the HRIA source area (EPA 2004). However, due to design and
funding issues, the pump and treat system was not implemented.
In 2005 and 2006, with the Breen RI activities still suspended, EPA assembled all of the
available investigation data that had been collected across the Site and released a draft, site-wide
RI and (FS reports. The FS concluded that aggressive source control at the HRIA, establishment
of institutional controls, and long-term monitoring of the PCE plume was the appropriate course
of action for the site as a whole (Parametrix 2006). However, upon further review of site-wide
data, EPA reconsidered this decision and pursued a more comprehensive strategy that would also
consider cleanup alternatives for other areas of the site in what is now known as OU2.
As part of the more comprehensive site-wide strategy, Parametrix, on behalf of EPA performed
supplemental groundwater and surface water sampling across the Site in July 2007 (Parametrix
2009). Seventeen existing wells were sampled (8 private wells and 9 monitoring wells) in the
HRIA, the Breen Property, the Thurman Berwick Creek Area, and downgradient areas west and
northwest of Labree Road. The purpose of the sampling was to evaluate whether significant
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changes in concentrations had occurred since the previous Site-wide sampling events in
2003/2004. The private wells sampled included five locations on Rice Road beyond the end of
the public water supply line installed in 2002. Two surface water samples were collected from
Dillenbaugh Creek. The data from this sampling were used to further define Site-wide
groundwater contamination, to assess contaminant migration, and to assess potential
groundwater-surface water interaction associated with Dillenbaugh Creek.
In November 2007, EPA's Environmental Response Team (ERT) took air samples in and around
private residences and commercial buildings across the site to assess possible risks to human
health from volatilization of contaminants from groundwater to indoor and outdoor (ambient) air
A total of 34 samples were collected over a 24-hour time period. Low levels of PCE and TCE
were detected inside most of the residential and commercial buildings, and in ambient locations;
however, the levels were low enough that they do not pose a current health risk (Lockheed
Martin 2008, EPA 2008, CDM Smith 201 lb).
Finally, in May 2010, EPA measured water levels and assessed the condition of most of the
monitoring wells at the Site. The results of this assessment, including a water level map, are
presented in Appendix C of the Draft Site-Wide RI Report (CDM Smith 201 la). After review of
additional data collected in 2007 and 2010, and revisiting older data that had been collected
across the Site, EPA has determined that there is enough reliable information about the
contamination at the HRIA to move forward with a preferred cleanup alternative for this source
area. Further studies are needed to further define the nature and extent of contamination and
determine options for cleaning up the rest of the Site.
More detailed information on previous investigations and findings about the Site can be found in
the Draft Site-Wide RI Report (CDM Smith 201 la).
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3.0 SITE CHARACTERISTICS
This section first describes the physical characteristics of the entire Site. It then shifts from a
site-wide perspective to focus on the HRIA by first describing the type and amount (called the
"nature and extent)" of contamination within the HRIA including a preliminary Conceptual Site
Model (CSM). For information on the nature and extent of contamination at other areas of the
Site, see the draft Site-wide RI Report (CDM Smith 201 la).
3.1 PHYSICAL CHARACTERISTICS
This subsection describes the climate, landscape features (topography), geology, hydrogeology
(groundwater and surface water), current and future land and resource uses, and ecology
(animals and plants) at the Site.
3.1.1 Climate
Average annual precipitation in the Chehalis area is about 47 inches, with December being the
wettest month (Western Regional Climate Center 2006). An estimated three quarters of the
annual precipitation falls during October through March. The climate of the region includes wet
winters and moderately warm, dry summers. The mean average annual temperature for the
Chehalis area is about 50 degrees Fahrenheit (°F).
3.1.2 Topography and Drainage
The Site lies within the Newaukum Prairie, a relatively flat area formed by the Newaukum River.
Hills bound the Prairie to the west and east, rising to elevations of 400 to 700 feet above mean
sea level (MSL). Site topography ranges from 195 to 210 feet above MSL. Surface water
drainage varies from location to location within the area depending on how close the surface
water features are, such as Berwick Creek, Dillenbaugh Creek, and the Newaukum River. The
valley generally slopes down to the northwest towards the Chehalis River. The regional
topography and drainages are shown in Figure 3-1.
3.1.3 Geology
Surficial (on the surface) deposits mapped for the Site area consist of alluvium and Newaukum
terrace unit glaciofluvial deposits (Weigle and Foxworthy 1962). The alluvial deposits are
referred to as the silt "cap," although some investigators have identified it as a silt and clay cap.
Nevertheless, this "cap" appears to be continuous across the Site and ranges between 1 and 15
feet thick. It creates locally-confined groundwater conditions in the underlying Newaukum
terrace unit.
The Newaukum terrace unit is a glaciofluvial deposit consisting of sand in a silt and clay matrix
that contains the shallow aquifer. The maximum depth of the shallow aquifer is about 50 feet
below ground surface (bgs).
A non-marine sedimentary unit described as thin-bedded "blue" clays (with occasional sand and
silt lenses) lies under the shallow aquifer. This bluish-gray clayey silt layer is about 100 feet
thick and hardens with depth (Dames and Moore 1994). This layer is believed to be Miocene-
Pliocene (Weigle and Foxworthy 1962) and has a fluvial or lacustrine origin. This unit is the
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aquitard that divides the shallow and deep aquifers at the Site. It appears to be continuous
beneath the Site, which is consistent with regional geologic information (Ecology 2005).
Below the silt and clay aquitard is a confined aquifer comprised of older Miocene alluvial
sediments deposited by a meandering or braided river system. The groundwater in the deep
aquifer occurs in sand lenses and channel deposits more than 150 feet deep and ranging from 5
to 70 feet thick in the area of the HRIA (Dames and Moore 1994). Wells installed in this aquifer
in the Newaukum River valley are typically artesian.
3.1.4 Groundwater
Beneath the HRIA, the groundwater flows to the west/northwest, but becomes northwesterly
downgradient of the Breen Property. Historic water levels have ranged between about 1.5 and 10
feet bgs. Water levels can vary several feet seasonally; in any individual well as much as a 6.47
foot difference has been observed. Regional investigations have categorized the shallow aquifer
in the HRIA as an unconfined or water table aquifer (Dames and Moore 1994; Ecology 2005).
In the HRIA, however, the shallow aquifer exhibits the characteristics of a confined or semi-
confined aquifer primarily due to the silt cap immediately above the shallow aquifer, and water
levels measured 4 to 6 feet above the base of this silt cap in December 2003 (URS 2004).
The overall groundwater slope (gradient) beneath the HRIA is 0.0063 foot per foot (ft/ft) (URS
2004). A localized steeper gradient (approximately 0.016 ft/ft) is apparent immediately
downgradient of North Hamilton Road. The average groundwater gradient calculated for the
entire site is 0.0032 ft/ft (E&E 2001).
Site-wide vertical gradients within the shallow aquifer are not well understood. There are only
five locations with paired monitoring wells screened in the shallow aquifer, and only four of
those locations have surveyed elevation data for both wells to enable calculation of vertical
gradients. Of these well clusters, two are in the southwestern area of the Breen Property, one is in
the northwestern area of the Breen Property, and one is just south of North Hamilton Road
between the HRIA and the Thurman Berwick Creek Area. The three locations within 200 feet of
Berwick Creek (MW-20/21, MW-22/23, and MW-29/30) have upward gradients, while the
cluster located further away (MW-17/18) has a downward gradient.
3.1.5 Surface Water
The Newaukum River is east of the Site and flows northwesterly where it joins with the Chehalis
River about five miles northwest of the Site. There are also two creeks that run through the Site;
Berwick Creek and Dillenbaugh Creek (Figure 1-2). In addition, there are two ditches with
intermittent flows that discharge into Berwick Creek at the HRIA. Both ditches pass under 1-5
and flow from east to west. Berwick Creek flows through the HRIA from southeast to northwest,
turns west at the Breen Property and extends about 1,500 feet where it turns towards the north-
northwest, meeting Dillenbaugh Creek about 2,100 feet further. Dillenbaugh Creek flows
roughly southeast to northwest through the downgradient area of the Site and discharges into the
Chehalis River.
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3.1.6 Land and Resource Uses
The Site is located in a rural region used for agricultural activities. An estimated 1,200 people
live within four miles of the Site and have been identified by EPA as being within the potential
area for adverse effects from PCE contamination from groundwater (E&E 2000). The
commercial district of the City of Chehalis is located about 2 to 2.5 miles northwest of the Site.
The boundary between the City of Chehalis and unincorporated Lewis County bisects the Site
roughly north to south along Labree Road. The HRIA and the portion of OU2 that is east of
Labree Road are located within the City of Chehalis' Urban Growth Area (UGA) and are zoned
Commercial General (CG). The Breen Property and the former United Rentals Property are
used for commercial purposes. Current land use downgradient (west and north) of Labree Road
consists primarily of rural open (Class B Farmlands) and residential (Rural Development District
[RDDJ-20) use and is not within the Chehalis UGA.
The shallow aquifer is used as a drinking water source for area residences not connected to the
City of Chehalis water system, and for cooking, bathing, irrigation, and stock watering by
residences, commercial businesses, and farms in the area. About 250 private water-supply wells
are located within four miles of the HRIA and the Breen Property (Farallon 2003).
The Site is designated as within the Usual and Accustomed (U&A) area for the Confederated
Tribes of the Chehalis Reservation, the Cowlitz Indian Tribe, and the Quinault Indian Nation.
Within the Site, Berwick Creek is classified as a Type F stream by the Washington State
Department of Natural Resources (DNR) [DNR 2010], A Type F stream is known to be used by
fish or meets the physical criteria to be potentially used by fish. Fish streams may or may not
have flowing water all year. There are no use designations specifically for Berwick Creek in
Ecology's Water Quality Standards for Surface Waters of the State of Washington (WAC 173-
201A-602, Table 602) (Ecology 2006). Ecology lists Berwick Creek as a Category 4A and 5
water body in the 2004 Water Quality Assessment 303(d) list (Ecology 2008) due to exceedances
of fecal coliform.
Dillenbaugh Creek is classified as a Type F stream by DNR upstream of where it merges with
Berwick Creek. Downstream of this area, however, the creek is classified as Type S. A Type S
stream is designated "shorelines of the state." There are no use designations specifically for
Dillenbaugh Creek in WAC 173-201A-602, Table 602. Ecology lists Dillenbaugh Creek as a
Category 4A and 5 water body in the 2004 Water Quality Assessment 303(d) list (Ecology
2008). The Category 4A listing is due to exceedances of fecal coliform. The creek is listed as a
Category 5 water body due to an exceedance of dioxin in fish tissue in a section of the creek
downstream from the confluence with Berwick Creek.
Future land and resource uses east of Labree Road are anticipated to be similar to current land
uses. A freeway interchange was built several years ago on Labree Road and additional
commercial use is planned for the area between the HRIA and the Labree Road/Thurman
Berwick Creek Area. Future land and resource uses in the area north and west of Labree Road
are also anticipated to be similar to current uses, unless it becomes part of the Chehalis UGA.
However, there are no plans for this designation at this time.
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3.1.7 Ecology
A variety of animals (e.g., birds, mammals, fish) and plants inhabit or use, or have potential to
inhabit or use, the creeks and land across the site. Birds such as the bald eagle, the American
Robin, and various ducks, such as the Mallard Duck, may visit the Site. A wide range of
mammals, including the short-tailed shrew, raccoon, and white-tailed deer, could also frequent
the Site.
Searches of wildlife databases and inquiries with regulatory agencies were conducted to
determine if any threatened and endangered species, and environmentally important animals and
plants are likely to be present at the site, especially near Berwick Creek. The only species of
special concern that uses certain reaches of Berwick Creek is the Coho salmon (Oncorhynchus
kisutch). Berwick and Dillenbaugh Creeks are designated as essential fish habitat for the Coho
and Chinook salmon (Oncorhynchus tschawytschd) under the Magnuson-Stevens Act. Berwick
Creek was identified as having Coho salmon spawning and rearing habitat in the lower reaches,
which would include areas both downstream and upstream of the HRIA (URS 2004).
A bald eagle nest has been documented about 1.25 miles southeast of the Site, near the
Newaukum River. Bald eagles (Haliaeetus leucocephalus) were recently delisted under the
Federal Endangered Species Act (ESA). It is possible that bald eagles in the area obtain food
from Berwick Creek.
For detailed information on the ecology of the site, see the Draft Site-Wide BLRA report (CDM
Smith 201 lb).
3.2 NATURE AND EXTENT OF CONTAMINATION
This subsection describes the nature and extent of contamination found within the HRIA.
3.2.1 Nature of Contaminants
The (COCs within the HRIA are PCE and its degradation products TCE, and cis-l,2-DCE, and
total petroleum hydrocarbons (TPH), such as from diesel and gasoline. Because PCE has been
detected more frequently and at much high concentrations than the other COCs and is the
primary risk driver within the HRIA, it is used as the representative COC in this Proposed Plan.
3.2.1.1 Principal Threat Wastes
Principal threat wastes are those source materials considered to be highly toxic or highly mobile
that cannot be reliably contained or would present a significant risk to human health or the
environment should exposure occur. The DNAPL present in the contaminated sediments and
soils in the HRIA are considered a principal threat waste. Note that contaminated groundwater
generally is not considered to be source material; however, DNAPL in groundwater may be
considered as source material (EPA 1991).
3.2.2 Extent of Contamination
This subsection describes the extent of contamination based on the results of investigations
conducted within the HRIA. See Figure 3-2 for historical sampling locations.
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Contaminants are found primarily in creek bed sediments and bank surface soils within the
HRIA Berwick Creek channel, and in subsurface soils and groundwater. In general, sediment
and surface soils are defined as 0 to 5 feet bgs. Subsurface soils are at depths greater than 5 feet
and typically start below the silt "cap" of Berwick Creek. Subsurface soil samples have typically
been collected between 5 feet bgs to the top of the shallow aquifer aquitard at about 50 feet bgs.
In groundwater, contamination occurs in the shallow aquifer located about 5 to 50 feet bgs.
PCE concentrations in sediment, soils and groundwater within the HRIA indicate the presence of
DNAPL. PCE concentrations indicative of DNAPL have not been detected on top of the
aquitard.
The deep aquifer below the aquitard has not been fully characterized. Minor amounts of PCE
have been detected in samples collected from private wells screened in the deep aquifer, but not
enough to suggest that significant migration of PCE through the aquitard that separates the
shallow aquifer from the deeper aquifer has occurred.
3.2.2.1 Release Area(s)
The most likely location of the HRIA release is just upstream of where the Unnamed Ditch #1
enters Berwick Creek near Monitoring Well (MW) 602 and MW-602, an area referred to as the
"Southeastern Hot Spot" (Figure 3-3). High PCE concentrations strongly point to a single
release at this location, but multiple releases may have occurred along a 400-foot reach of
Berwick Creek. Data supporting this latter assumption include high PCE concentrations
identified in an area referred to as the "Northwestern Hot Spot" which begins about 80 feet
downstream of Unnamed Ditch #1 (Figure 3-3) (CDM Smith 201 la). PCE contamination within
these Hot Spots is discussed further in the below subsections.
3.2.2.2 Berwick Creek Channel Bed and Banks
Currently, the only identified sediment and surface soils in the HRIA with PCE concentrations
indicative of DNAPL are in the bed and banks of the Berwick Creek channel. The creek bed is at
an elevation of about 199 to 200 feet above MSL.
During the August 2003 HRIA EE/CA investigations, URS collected 39 samples from creek bed
sediments and bank surface soils along Berwick Creek and both unnamed ditches in the HRIA.
The maximum PCE concentration detected was 5,220 mg/kg in creek bed sediment/soil boring
(SB) sample SB-409, located at the upper boundary of the Southeastern Hot Spot (Figure 3-4).
Concentrations indicative of DNAPL in sediment and soil are those that exceed the soil
saturation limit of PCE, which in the HRIA is 38 mg/kg of PCE. Other creek bed sediment and
bank soil sample locations indicating PCE DNAPL were at SB-410 (1,610 mg/kg) and at SB-411
(685 mg/kg) (URS 2004).
PCE concentrations in creek bed and bank samples within and north of the Northwestern Hot
Spot ranged from non-detect to 0.0887 mg/kg at SB-403(URS 2004). No creek bed sediment and
bank soil samples have been collected in the far northern portion of the HRIA, particularly in the
segment between MW-R4 in the Northwestern Hotspot and MW-5/MW-33 (Figure 3-2). Breen
(Farallon) collected one creek channel (CC) sample in the very north of the HRIA just south of
the Chehalis Livestock Auction building, but PCE was not detected. It should be noted, however,
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that Farallon did not use the correct method for preserving this and other soil samples, which
could be a reason for not detecting PCE. Additional creek bed sediment and bank soil samples,
as well as surface soil samples outside of the Berwick Creek channel within the HRIA will be
collected during pre-design activities.
3.2.2.3 Subsurface Soil
PCE concentrations high enough to indicate the presence of DNAPL have been observed in
subsurface soils beneath the apparent PCE release area in Berwick Creek. The highest PCE
concentration in subsurface soil, 3,220 mg/kg, was detected at GP-502 at a depth of 28 feet bgs
in the Southeastern Hot Spot. As described earlier, sediment and soil concentrations greater than
38 mg/kg of PCE indicate the presence of DNAPL in the HRIA (URS 2004). In general, the
highest subsurface PCE concentrations were found at GP-501 (858 mg/kg at 12 feet bgs), AB-
650 (136 mg/kg at 21 feet bgs), and GP-503 (151 mg/kg at 28 feet bgs) (Figure 3-2) and at MW-
9 (53 mg/kg) at 43 ft and MW-602 (399 mg/kg at 15 feet bgs) (Figure 3-3).
3.2.2.4 Groundwater
The maximum PCE concentration in groundwater (2,720,000 (J,g/L) was detected at MW-602
within the Southeastern Hot Spot in November 2003. Concentrations that exceed 10% of a
contaminant's solubility limit in groundwater indicate DNAPL. PCE's solubility limit is
200,000 (J,g/L; therefore, a concentration of 20,000 |ig/L or higher in groundwater is indicative of
PCE DNAPL.
Maximum PCE concentrations in groundwater within the Northwestern Hot Spot were detected
in February and November 2003 at MW-R4 at 5,300 [j,g/L and 8,800 (J,g/L, respectively.
Dissolved PCE in groundwater appears to have migrated northwest of the Northwestern Hot
Spot, based on data collected by Farallon (Farallon 2004). A groundwater sample at MW-33,
located northwest of the Northwestern Hot Spot, contained PCE at 1,100 [j,g/L in April 2004.
Groundwater data within the HRIA suggest stratification of PCE within the shallow aquifer.
The upper zone of the shallow aquifer, at or above 25 feet bgs, shows higher PCE concentrations
than in the lower zone of the shallow aquifer (25 feet bgs down to the top of the silt and clay
aquitard). The 20- to 30-foot zone appears to be a transition or mixing zone often characterized
by intermediate concentrations.
Multi-level sampling was conducted to assess the potential stratification of the PCE plume in
groundwater at the Southeastern Hot Spot and the area immediately downgradient. Results at
MW-R8 showed significantly higher PCE concentrations in the upper zone as compared to the
lower zone. PCE concentrations ranged from 4,700 [j,g/L at 15 feet bgs to 360 [j,g/L at 48.5 feet
bgs. Multi-level sampling in MW-R11 did not indicate a significant variation in PCE
concentrations in groundwater samples collected at varying depths, however, PCE concentrations
were relatively low at about 25 (J,g/L.
Multi-level samples were also collected from all of the MW-600-series wells when they were
installed in October and November 2003. The most dramatic stratification was observed inMW-
602, which had 2,720,000 [j,g/L PCE in the 14.5-foot sample, 203,000 [j,g/L in the 35-foot
sample, and 4,980 [j,g/L in the 41-foot sample. It should be noted, however, that stratification
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within the shallow aquifer needs further characterization due to limited information available
regarding the protocols that were followed for the multi-level sampling effort.
Stratification also appears to be evident downgradient of the HRIA. The contour lines in
Figure 3-5 show the maximum concentrations detected in the upper zone of the shallow aquifer
from the HRIA to the Thurman Berwick Creek Area and to the southwest corner of the Breen
Property. Figure 3-6 shows the maximum concentrations detected at sampling points in the
lower zone of the shallow aquifer from the HRIA to the Thurman Berwick Creek Area and the
southwest corner of the Breen Property. A comparison of the two figures suggests that
contamination in the upper zone declines to negligible concentrations by the HRIA western
boundary. However, contamination in the lower zone of the shallow aquifer extends well beyond
the HRIA boundary. This trend is reversed at the Thurman Berwick Creek Area and southwest
corner of the Breen Property where PCE concentrations greater than 2,000 |ig/L have been
observed in the upper zone and are greater than the PCE concentrations in the lower zone at this
area. The reasons for this need to be evaluated during future OU2 investigations.
The maximum extent of the PCE has not been fully delineated. Figure 1-2 shows the Site-wide
estimated extent of PCE based on limited data. After crossing under Labree Road, the plume
turns in a north-northwesterly direction, essentially following Berwick and Dillenbaugh Creeks.
3.2.2.5 Surface Water
Two of the 10 surface water sampling stations are located downgradient of the Southeastern Hot
Spot (SW-3 and SW-7) and at the downstream portion of the Unnamed Ditch #1 west of 1-5
(SW-5) as are shown on Figure 3-4. SW-5 and SW-7 have been sampled four times between
July 2002 and November 2003 and SW-3 once in July 2008. The detections and concentrations
of PCE in surface water samples at these locations have varied considerably and no clear
seasonal trend has been identified. The highest concentrations of PCE at SW-5 (40 (J,g/L) and
SW-7 (12 |ig/L) occurred in November 2002, typically a high rain or snowfall month, however
the PCE concentration at SW-3 in July 1998 was similarly high at 15 (J,g/L; although this station
was only sampled once and the other stations were not sampled on this date.
Two additional stations are located upstream of the HRIA. SW-4, located in the upstream portion
of Unnamed Ditch #1 east of 1-5, was sampled once by Ecology in December 1998; PCE was not
detected. SW-6, located near the upstream limit of known contamination in Berwick Creek soils,
was sampled four times between July 2002 and February 2003. PCE was detected at
concentrations less than 1 |ig/L in July 2002 and November 2003, but was not detected during
the other two sampling events.
No surface water sampling has been completed in Berwick Creek in the northern part of the
HRIA between MW-R4 and MW-5/MW-33. High PCE concentrations have been detected in
groundwater sampled from MW-R3 (Northwestern Hot Spot) and MW-33. It is unknown if
contaminated groundwater near these wells discharges to surface water.
3.2.2.6 Soil Gas
Soil gas surveys were conducted near Berwick Creek and 1-5 within the HRIA in August 2003.
PCE concentrations ranged from non-detect to 18 parts per million by volume (ppm-v). Positive
soil gas survey results are used to determine whether more intensive soil sampling should be
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completed in an area. In addition, soil gas surveys are useful in determining whether vapor
intrusion could be a potential issue. Vapor intrusion is the process in which chemical vapors
from contaminated soil or groundwater affect the indoor air quality in a building. While the soil
gas survey results do not appear to point to any current issues, the results suggest that monitoring
associated with future characterization and remediation efforts at the HRIA include sampling to
further evaluate the potential for vapor intrusion.
3.2.2.7 Indoor and Ambient Air Quality
Samples were collected from indoor air, ambient (outside) air and sub-slab soil vapors in
November 2007 (see Figure 3-7. PCE was detected in all four samples collected at buildings
within the HRIA, with the maximum concentration occurring in the sub-slab sample below the
paint shop building on the former United Rentals Property (25 micrograms per cubic meter
[|ig/m3]). While the indoor and ambient air quality sampling results do not appear to point to any
current issues, the results, particularly the sub-slab sample result collected below the paint shop
building, suggest that monitoring associated with future characterization and monitoring efforts
include sampling to further evaluate the potential for vapor intrusion.
3.2.3 Estimates of PCE Mass, Volume, and Surface Area within the HRIA
Three dimensional (3-D) modeling using Ctech's Mining Visualization Systems (MVS) Version
9.13 was used to help better define the vertical and lateral extent of PCE contamination within
the HRIA, and to help provide estimates for PCE mass, volume, and surface area (see Table 3-
1). Total mass levels were calculated assuming that PCE concentrations in soil samples represent
mass sorbed to soil, mass dissolved in groundwater, and mass as DNAPL. Groundwater sample
concentrations represent PCE dissolved in groundwater and as DNAPL.
3.3 PRELIMINARY CONCEPTUAL SITE MODEL
A preliminary conceptual site model (CSM) has been developed for the Hamilton/Labree site.
The CSM is based on consideration of site background information and data collected from
investigations done at the Site. The CSM tells the story of when and where the Site was
contaminated, what media was affected, where the contamination migrated (called pathways),
and who and what can potentially be harmed from the contamination (called receptors). More
data needs to be collected both inside and outside of the HRIA in order to further refine the
CSM. A graphical depiction of the CSM is presented in Figure 3-8 A narrative summary of the
CSM is provided below.
Sometime before 1990, based on the estimated extent of the contaminated groundwater plume in
1993, an unknown entity released pure, liquid PCE into Berwick Creek within the HRI. Berwick
Creek is a low velocity stream for most of the year, except when heavy rains or major flooding
events occur. Assuming the creek was at a low velocity when the PCE was release, most of it
likely sank to the creek bottom rather than being transported by surface water downstream. It
would have then spread downstream and a little way upstream (due to localized stream
topography) and pooled in low areas. PCE concentrations within Berwick Creek bed sediment
and bank soil are indicative of DNAPL (greater than 38 mg/kg; the soil saturation limit of PCE).
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The PCE DNAPL then quickly migrated through the one-foot- thick layer of creek bed sediment
and the underlying silt "cap," and into the subsurface soil and groundwater within the shallow
aquifer. Typically, fine grained material like those in the Berwick Creek bed sediment, and to a
lesser extent the thin layer of silt immediately beneath the sediment, would sorb (bind) the PCE
enough to slow its downward migration into the shallow aquifer. However, it appears that the
large volume of PCE that was released into Berwick Creek overwhelmed the capacity of the
creek bed sediment and underlying cap to contain the spill.
The sand and gravel shallow aquifer is highly permeable, making it easy for the dissolved phase
plume to move downward and downgradient. Once in the shallow aquifer, the PCE appears to
have continued to move in an irregular pattern following lenses of higher permeability soils.
High concentrations of PCE were found sorbed (bound) to the soil particles under and near the
creek. The soil and groundwater data suggest that the PCE mass has tended to be absorbed by
and pooled on top of the occasional, discontinuous lower permeability silt lenses in the upper
zone of the aquifer (25 feet bgs and above), slowing further PCE migration. PCE concentrations
generally (but not always) decrease with depth within the HRIA. In some areas below the release
area, low concentrations of PCE were detected in the upper material of the silty/clay aquitard
found at 50 feet bgs, but the presence of DNAPL has never been indicated.
For information on receptors and the potential adverse impacts from contaminants, see Section 5
of this Proposed Plan, and the Draft Site-Wide BLRA report (CDM Smith, 201 lb).
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4.0 SCOPE AND ROLE OF PROPOSED INTERIM CLEANUP ACTION
This section briefly describes EPA's intent to address the Hamilton/Labree Site in a phased
approach starting with an interim cleanup action within the HRIA selected from the Preferred
Alternative or other alternatives considered in this Proposed Plan.
According to the National Oil and Hazardous Substance Pollution Contingency Plan (NCP)
[40 Code of Federal Regulations [CFR] 300.430(a)(l)(I)], the goal of the remedy (cleanup)
selection process is "to select remedies that are protective of human health and the environment,
maintain protection over time, and minimize untreated waste." Expectations for contaminated
groundwater as stated in the NCP are as follows: "EPA expects to return usable groundwaters to
their beneficial uses wherever practicable, within a timeframe that is reasonable given the
particular circumstances of the site. When restoration of groundwater to beneficial uses is not
practicable, EPA expects to prevent further migration of the plume, prevent exposure to the
contaminated groundwater, and evaluate further risk reduction." (Federal Register, 1990a;
§300.430 (a)(l)(iii)(F), emphasis added.)
EPA Guidance, (specifically the Presumptive Response Strategy AndEx-Situ Treatment
Technologies For Contaminated Ground Water At CERCLA Sites, OSWER Directive 9283.1-
12, October 1996) recommends that site characterization should be coordinated with cleanup
actions and both should be implemented in a step-by-step or phased approach. In a phased
approach, early or interim actions should be used to reduce site risks (by addressing known
sources of contamination, reducing risks from exposure to contamination, and by reducing or
preventing the further migration of contaminants), and to provide additional site data to be
followed by a later, more comprehensive action (the long-term cleanup action). Specific
objectives for the long-term cleanup are not established until after performance of the earlier
interim action is evaluated and used to assess the likelihood that groundwater restoration (or
other appropriate objectives) can be attained. Separate decision documents are used, in which
cleanup objectives are specified that are appropriate for each action.
In keeping with the above regulations and guidance, EPA is using a phased that to first addresses
the known sources of PCE contamination to sediment, soil, and groundwater and prevent risks
within the HRIA, and to minimize further migration of contaminated groundwater from the
HRIA. Doing so will also address the principal threat waste, identified as PCE DNAPL, in the
HRIA. The proposed interim cleanup action will be selected, after considering public comments,
in an Interim ROD.
Although there appears to be other contamination sources at the Site outside of the HRIA,
however, additional site-wide data collection and evaluation is needed to develop, select and
implement other cleanup action(s) for the Site that will achieve long-term protection of human
health and the environment.
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5.0 SUMMARY OF SITE RISKS
CERCLA requires EPA to protect human health and the environment from current and possible
future exposures to hazardous substances at Superfund sites. To evaluate exposure risks, EPA
conducts studies called Baseline Risk Assessments (BLRAs). The BLRA estimates what risks
the site poses if no cleanup action were taken. It provides the basis for taking action and
identifies the contaminants and exposure pathways that need to be addressed by the interim
cleanup action. This section of the Proposed Plan summarizes the results of the BLRA
conducted for the Hamilton/Labree Superfund Site as it relates to the HRIA (CDM Smith
2011b).
5.1 HUMAN HEALTH RISKS
The potential adverse effects on human health from being exposed to contaminants from a
Superfund site are expressed in terms of cancer-causing (carcinogenic) risks (individual excess
lifetime cancer risks) and non-carcinogenic hazard levels (hazard indices or [His]). EPA's
acceptable target range for carcinogenic risk is 1 in ten thousand to 1 in one million (1 x 10"4 to 1
x 10"6) individual excess lifetime risk of developing cancer from the contaminants at a site, and
the acceptable non-carcinogenic target hazard level is a HI of less than 1.0. The estimated
carcinogenic risks and non-cancer hazards for four categories of people who may be exposed to
contamination within or near the HRIA are as follows:
HRIA Commercial/Industrial Worker: Individual excess lifetime cancer risks and non-cancer
hazards were estimated for a long-term commercial/industrial employee working (250, 8-hour
days per year for 25 years) at either the main building or the paint shop on the former United
Rentals Property. Exposure to contaminants in soil and groundwater were evaluated. Under
current use scenarios, where workers are not drinking groundwater, the individual excess lifetime
cancer risks and, non-cancer His) were less than 8 x 10"5 and 1.0, respectively. If chemical
concentrations persist in groundwater and it is used as a drinking water source in the future, over
time the estimated individual excess lifetime cancer risks would be about 1 x 10"1 and the non-
cancer His would be elevated (HI = 55). The United Rentals Property is currently on the
Chehalis public water supply system which makes this an unlikely scenario.
HRIA Construction/Utility Worker/Trench Worker): Individual excess lifetime cancer risks
and non-cancer hazards were estimated for a short-term construction/utility employee (20, 8-hour
days per year for one year) working within the HRIA. Exposure to contaminants in soil,
groundwater, and outdoor air were evaluated.
Under current uses, where workers are not drinking groundwater, the individual excess lifetime
cancer risks and HI were less than 1 x 10"6 and 1.0, respectively, from exposure to soil and
outdoor air. If chemical concentrations persist in groundwater and it is used as a drinking water
source in the future, over time the estimated individual excess lifetime cancer risks would be
about 3 x 10"4 and the non-cancer His would be 4.4.
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The most significant potential exposure pathway is inhalation of COCs (primarily PCE and TCE)
from groundwater by construction and utility employees who work in trenches within the HRIA.
Based on estimates of trench air concentrations at three HRIA subareas and assuming a total
exposure of 500 hours over a course of one year, the individual excess lifetime cancer risks
ranged from 2 x 10"3 to 4 x 10"5 and the non-cancer His ranged from 1.3 to 121. Given these
high risk estimates even the assumption of a much lower exposure duration by workers in HRIA
subarea trenches would have resulted in estimates of unacceptable risk. It should be noted,
however, that the accuracy of the model for estimating concentrations in trench air from
groundwater concentrations has not been validated for the Site and thus represents a large
uncertainty.
HRIA Trespasser: The individual excess lifetime cancer risks for a trespasser at the HRIA
exposed to soil and outdoor air were estimated to be less than that of a construction or utility
worker (less than 1 x 10"6). This was based on the assumption that a trespasser would be exposed
for a shorter period of time.
HRIA Berwick Creek Recreator: Individual excess lifetime cancer risks and non-cancer HI
were estimated for adults and children recreating infrequently at Berwick Creek within the
HRIA. Exposure to contaminants in surface water and sediment were evaluated. At Berwick
Creek, the estimated individual excess lifetime cancer risks were about 2 x 10"4 for both adults
and children which were predominately driven by PCE concentrations in sediment. The non-
cancer HI for both adults and children was less than 1.0.
5.2 ECOLOGICAL RISKS
Estimates of risks to ecological receptors from Superfund site contaminants are expressed in
terms of hazard quotients (HQs) in this Proposed Plan. The acceptable target hazard level is a
HQ of less than 1.0. The estimated HQ's for four categories of ecological receptors within and
near the HRIA are as follows:
Wildlife: Several types of birds (bald eagle, American Robin, Mallard Duck) and mammals
(short-tailed shrew, raccoon, white-tailed deer) were evaluated. No elevated risks for bald eagle
were identified. However, risks for American Robins (HQs = 1.3 to 11) and Mallard Ducks
(HQs = 3) were elevated for PCE primarily due to their high soil/sediment ingestion rate and the
elevated PCE concentrations identified in Berwick Creek sediments. Elevated risks were also
found for shrews at the HRIA primarily from inhalation of PCE in burrow air (HQ = 50). Both
raccoons (HQs = 8.5 to 43) and deer (HQs = 1.2 to 6.6) had elevated risks at the HRIA primarily
from the high PCE concentrations found in Berwick Creek sediments.
Aquatic Life: Aquatic receptors, (e.g., salmon and rainbow trout), were evaluated for direct
contact to chemicals in the surface waters of Berwick Creek. Potential PCE and TCE risks to
these receptors are negligible.
Benthic Organisms: Benthic organisms live at the bottom of water bodies and are important
links in the food chain providing a food source for fishes, birds and mammals. Due to the lack of
biologically relevant creek bed sediment samples taken in Berwick Creek, HQs were not able to
be estimated. However, given that the maximum PCE concentrations measured in Berwick Creek
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exceed sediment quality benchmarks by 3 to 4 orders of magnitude, it is possible that benthic
organisms are negatively impacted by contamination within the HRIA,
Terrestrial Plants: The terrestrial plant HQs from exposure to soils did not exceed 1.0 for any
exposure are or COC. However, the terrestrial plant HQ from exposure to groundwater within
the HRIA exceeded 1.0. This suggests that plants with root systems deep enough to encounter
PCE-contaminated groundwater may be adversely affected.
5.3 BASIS FOR ACTION
Generally, where the BLRA indicates that a cumulative site risk to an individual using
reasonable maximum exposure assumptions for either current or future land use exceeds the
lxlO"4 individual excess lifetime cancer risk end of the risk range, or if MCLs are exceeded,
action under CERCLA is generally warranted at the site. Where the non-carcinogenic risk to
humans exceeds a hazard quotient of 1, action under CERCLA may also be warranted.
At the HRIA, PCE concentrations in groundwater far exceed the MCL and the risk assessment
showed that if PCE concentrations persist in groundwater and it is used as a drinking water
source in the future risks to humans would be approximately lxlO"1. Risks to workers from
inhalation exposures to PCE in trench air within the HRIA could also pose significant risks, with
carcinogenic risk estimates as high as 2xl0"3 and a non- cancer HI up to 121. There are also
elevated risks to shrew from burrow air (HQ = 50), and to raccoon (HQs up to 43) and deer (HQs
up to 6.6) from ingestion of sediment and soil within the Berwick Creek channel.
Therefore the proposed Preferred Alternative identified in this plan, or one of the other active
measures, is necessary to protect public health or welfare or the environment from actual or
threatened releases of hazardous substances into the environment.
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6.0 REMEDIAL ACTION OBJECTIVES
Remedial Action Objectives (RAOs) provide a general description of what a cleanup action is
intended to accomplish, in terms of contaminants and media of concern, potential exposure
pathways, and cleanup (remediation) goals. Preliminary remediation goals (PRGs) are the
more specific statements of what the cleanup action's endpoint concentrations or risk levels, for
each exposure route, are to be in order to provide adequate protection of human health and the
environment. RAOs and PRGs are developed and refined during the RI/FS based on federal and
state environmental laws and the results of the remedial investigations, including the human and
ecological risk assessments, to guide the development and evaluation of cleanup alternatives.
Final remediation goals are determined and documented in the Record of Decision as cleanup
levels.
As explained earlier in the Scope and Role Section, EPA is proposing to address the Site with a
phased approach, starting with an interim action in the HRIA, which will eventually be followed
by additional action(s). The RAOs for the proposed interim action are presented below, followed
by the associated PRGs to meet these RAOs within three cleanup (remediation) target zones that
will be the focus for this interim cleanup action.
6.1 HRIA RAOs
The following RAOs are proposed for the HRIA interim cleanup action:
1. Prevent human exposure to groundwater in the HRIA containing COCs above levels
protective for drinking water.
2. Prevent human exposure to COCs in HRIA sediment and soil above levels that are
protective of recreational users and construction/utility (trench) workers.
3. Prevent ecological exposure to COCs in HRIA sediment and soil above levels that are
protective of ecological receptors.
4. Reduce the DNAPL contaminant mass and subsurface soil contamination within the
HRIA to minimize further migration of COCs from the HRIA to downgradient
groundwater.
These RAOs and the associated PRGs discussed below address COCs (primarily PCE3) in
sediment, soil and groundwater and the risks associated with these contaminants within the
HRIA as identified in the risk assessment. Taking action to address these RAOs will also reduce
or eliminate HRIA sources of contamination to downgradient groundwater. These RAOs also
address the principal threat waste in the HRIA, identified as PCE DNAPL.
3 As stated in Section 3, the COCs at the HRIA are PCE, TCE, cis-l,2-DCE, and TPH. Since PCE has been detected
more frequently and at much higher concentrations than the other COCs, it is considered the primary risk driver and
is considered the "indicator" or "reference" COC in this Proposed Plan.
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6.2 PRELIMINARY REMEDIATION GOALS
Preliminary Remediation Goals (PRGs) are developed based on applicable or relevant and
appropriate requirements (ARARs) from federal and state environmental and state standards.
Where standards do not exist or provide an adequate level of protection then PRGs are based on
risk-based calculations of acceptable exposure levels. CERCLA Section 121 requires that
cleanup actions at Superfund sites must achieve a level of cleanup which, at a minimum, ensures
protection of human health and the environment. CERCLA and the NCP also require cleanup
actions to comply with the substantive provisions of ARARs during and at the completion of
cleanup actions, unless legal waivers are obtained. Potential HRIA ARARs and TBCs are listed
in Tables 6-1 through 6-3.
The Preferred Alternative, and the other alternatives considered for the HRIA, were developed
and evaluated for use as interim cleanup actions as described in the Scope and Role section 4.
Consequently, none of the Alternatives evaluated are expected to be able to fully attain all of the
ARARs for the HRIA. The ARARs that will be attained and those that will be waived will be
specified in the Interim ROD, which is expected to include the interim action waiver provided
for in Section 121(d)(4)(A) of CERCLA. The Interim ROD will be followed by a Final ROD for
the HRIA or the Site that will fully address compliance with all ARARs, consistent with
CERCLA, including any waivers. The key ARARs to be addressed by this interim action are
discussed below.
6.2.1 Key Factors for Setting HRIA Interim Action PRGs
The key ARARs considered for setting the HRIA interim cleanup action PRGs include the
following:
• Federal and State Drinking Water Standards and more specifically, Maximum
Contaminant Levels (MCLs). MCLs apply to drinking water at the tap but are relevant
and appropriate for groundwater that is a potential source of drinking water; therefore,
these must be met or waived by the completion of cleanup action. The MCL for PCE is
5pg/L. All of the alternatives considered (except the No Action alternative) include
institutional controls to prevent human exposure to groundwater above this standard, but
restoration of the shallow groundwater aquifer to meet the standard is beyond the scope
of this interim action.
• Washington State MTCA soil cleanup standards for unrestricted use are outlined in WAC
Section 173-340-740. These are considered more appropriate than the standards for
industrial use in WAC Section 173-340-745 since the current and reasonably anticipated
future land use is a mix of industrial, commercial and recreational uses. All alternatives
considered (except the No Action alternative) would comply with the MTCA Method B
cleanup level for human direct contact exposure with soils, which requires cleanups to
attain the 1x106 risk level for protection of human direct contact exposure. The PCE
concentration which equates to a 1x106 risk from direct contact assuming residential use
is 22 mg/kg, industrial/commercial use is 110 mg/kg, and recreational use is 924 mg/kg.
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Other key factors that form the basis for the PRGs include:
• The Superfund program goal and expectations in the NCP Section 300.430(a) (iii) (F) "to
return usable groundwaters to their beneficial uses, wherever practicable, within a
timeframe that is reasonable given the circumstances of the site. When restoration of
groundwater to beneficial uses is not practicable, EPA expects to prevent further
migration of the plume, prevent exposure to contaminated groundwater, and evaluate
further risk reduction." The alternatives considered would do the latter.
• The Baseline Risk Assessment and Regional Screening Levels (RSLs). The BLRA was
used to identify exposed populations and exposure pathways by media and protective site
specific levels where adequate data was available, and where not, RSLs were used.
RSLs are risk-based, contaminant-specific levels or concentrations that set concentration
limits using carcinogenic or systemic toxicity values under specific exposure conditions.
For example, all alternatives considered (except the No Action alternative) the EPA RSL
for protection of shrew, a terrestrial ecological receptor, from ingestion and inhalation of
surface soil in burrow air (and from food uptake). In addition, given the absence of
freshwater sediment standards for protection of aquatic receptors, the EPA freshwater
RSLs were used to set a design performance goal to guide the restoration of the creek
channel and reduce the risk to aquatic receptors from direct contact/ingestion of
contaminated sediment and soils within the bed and banks of the Berwick Creek channel.
• Technology limitations and uncertainties associated with the proposed interim cleanup
actions.
• Site characterization data are not sufficient to determine the likelihood of attaining long
term objectives including restoration of groundwater and the timeframe for doing so, if
practicable.
6.2.2 HRIA PRGs for Each Remediation Target Zone
To achieve the RAOs for the proposed interim cleanup action, PRGs for PCE are established for
three, media-specific areas within the HRIA that are targeted for cleanup. These areas are called
"remediation target zones." The mass, volume and surface area of each zone is presented in
Table 6-4. A summary of each zone, the associated PRG and the RAOs these would address are
shown in Exhibit 6-1 and discussed in more detail below. Note there is no PRG proposed or
discussed below for RAO #1 because the MCL for human consumption of groundwater is 5
pg/L, and achievement of the MCL is beyond the scope of this interim action (it will be
addressed in subsequent decisions). For this interim cleanup action, ICs to prohibit use of HRIA
groundwater for drinking are the only means of achieving RAO 1.
6.2.2.1 Creek Bed Sediment and Bank Surface Soil Remediation Target Zone
Figure 6-1 shows the proposed remediation target zone where creek bed sediment and bank
surface soils at depths less than or equal to 5 feet bgs within the Berwick Creek channel are
currently contaminated with PCE at levels equal to or greater than 0.468 mg/kg. 0.468 mg/kg
PCE was used to define this zone's boundary based on EPA's fresh water RSLs for protection of
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Exhibit 6-1: PRGs for PCE by Target Zone for Each RAO
RAOs
ARAR
PRG by RAO for Creek
Bed Sediment/Bank
Surface Soil Target
Zone
PRG by RAO for
Subsurface Soil
Target Zone
PRG by RAO for High
Concentration
Groundwater Target Zone
(PCE concentration
greater than 4,000 |jg/L)
1) Prevent human
exposure to groundwater
in the HRIA containing
COCs above levels
protective for drinking
water.
5 |jg/L PCE - 40
CFR 141.11 -.16
(MCLs)
5 |jg/L PCE -
WAC 173-340-
720
NA
NA
No PRG: ICs will be used
for this Interim Action
2) Prevent human
exposure to COCs in
HRIA sediment and soil
s, surface soil and
subsurface soil above
levels that are protective
of recreational users and
construction/utility
(trench) workers
WAC 173-340-
740,-745 (soil)
22 mg/kg PCE
(residential)
110 mg/kg PCE
(industrial
commercial)
924 mg/kg PCE
(recreational)
10 mg/kg PCE
10 mg/kg PCE
NA
3 Prevent ecological
exposure to COCs in
HRIA sediment and
surface soil above levels
that are protective of
ecological receptors.
WAC 173-204-
570 (sediment)
EPA RSL for
terrestrial
ecological
receptor 9.92
mg/kg PCE
10 mg/kg PCE
NA
NA
4 Reduce the DNAPL
contaminant mass and
subsurface soil
contamination within the
HRIA to minimize further
migration of COCs from
the HRIA to
downgradient
groundwater
WAC 173-340-
740,-745 (soil)
22 mg/kg PCE
(residential)
110 mg/kg PCE
(industrial
commercial)
924 mg/kg PCE
(recreational)
10 mg/kg PCE
10 mg/kg PCE
Reduce mass discharge
of PCE contamination by
90%
Notes:
While not a PRG,
requirements that are
protective of ecological
receptors would need to
be met for relocation or
reconstruction of the
Berwick Creek channel
bed and banks, e.g.,
0.468 mg/kg PCE based
on EPA's RSLs for
freshwater sediments
MCL for PCE =5 (jg/l but
reaching this number is
beyond the scope of this
interim action
aquatic organisms from PCE in sediments, and because the majority of the surface soil
contamination found to date within the HRIA is within the bed and banks of the current Berwick
Creek channel. According to the conceptual site model, this zone represents the area where PCE
was directly released, and is delineated separately from surface soil outside of the creek channel,
and from subsurface soil and groundwater.
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The PRG proposed for the creek bed sediment and bank surface soil remediation target zone is to
10 mg/kg PCE. Maximum PCE concentrations in this zone ranged from 685 mg/kg to 5,220
mg/kg. These values are indicative of DNAPL as they exceed the soil saturation limit for PCE in
the HRIA (38 mg/kg). However, due to the difficulty in analyzing DNAPL in soil borings and
uncertainty in the data quality of the soil samples, there was a need to establish a more
conservative "cutoff" concentration to account for the characterization uncertainty. In addition,
the 10 mg/kg PRG would be well below the MTCA Method B cleanup level for human direct
contact exposure with soils which requires cleanups to attain the 1x106 risk level for protection
of human direct contact exposure with soil. The PCE concentrations which equate to a 1x10 6
risk from direct contact assuming residential use are 22 mg/kg, industrial/commercial and
construction/utility (trench worker) uses is 110 mg/kg, and recreational use is 924 mg/kg.
Finally, the EPA RSL that is protective for the ecological receptor considered most sensitive and
representative for the HRIA, the shrew, is 9.92 mg/kg PCE, but this RSL is conservative and is
based on ingestion of soil and food uptake. Due to all the above, a value of 10 mg/kg PCE is
proposed for this zone.
While not a PRG, protection of benthic and freshwater organisms within the creek bed sediment
and bank soils of the Berwick Creek channel from PCE concentrations > 0.468 mg/kg would be
accomplished when restoring the creek channel. The 0.468 mg/kg level was set based on an EPA
fresh water benchmark RSL for PCE in sediments.
Achievement of this PRG would address RAOs 2 and 3 as they pertain to the creek bed sediment
and bank soil of the current Berwick Creek channel and surface soils within the HRIA.
6.2.2.2 Subsurface Soil Remediation Target Zone
Figure 6-2 shows the proposed remediation target zone for subsurface soils. This zone is defined
as the area where subsurface soils at depths between 5 to 50 feet bgs are contaminated with PCE
levels greater than 10 mg/kg.
As with the Creek Bed Sediment and Bank Surface Soil Remediation Target Zone, a PRG of 10
mg/kg PCE was set for the Subsurface Soil Remediation Target Zone based on the potential for
DNAPL to be present in subsurface soil. Maximum PCE concentrations in HRIA subsurface
soils ranged from 53 mg/kg to 858 mg/kg. Using the 10 mg/kg value provides a good safety
factor (26% of the PCE saturation limit of 38 mg/kg), and is below the MTCA Method B cleanup
standards for direct contact with soil for PCE, which equates to a risk level of 1x106
Achievement of this PRG would address RAOs 2 and 4 as they pertain to subsurface soil.
6.2.2.3 High Concentration Groundwater Remediation Target Zone
Figure 6-2 shows the remediation target zone for high concentration groundwater. This zone is
defined as the area where groundwater at depths between 5- to 50 feet bgs are contaminated with
PCE levels greater than 4,000 ^ig/L.
The 4,000 ^ig/L level was set based on the potential for DNAPL to be present, and because
approximately 87% of the contaminant mass in subsurface soil and groundwater found in the
HRIA is within the >4,000 ^ig/L isocontour. The maximum PCE concentration in groundwater
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was detected at MW-602 (2,720,000 ng/L) under the suspected release area. Concentrations that
exceed 10% of a contaminant's solubility limit in groundwater are indicative of DNAPL. PCE's
solubility limit is 200,000 ng/L; therefore, concentration of 20,000 ^ig/L or higher in
groundwater are indicative of PCE DNAPL within the HRIA.
For the HRIA, while concentration-based data provide information about contaminant levels at
specific measuring points, it does not address the level which contaminants are being mobilized
from the source area into the downgradient areas. Measuring mass discharge (Md) or flux of
contaminants from a source area combines chemical data, groundwater flow velocity, and
discharge area into a single measurement (expressed as mass/time or grams/day). Using Md as a
performance measure or PRG is a more direct way to measure contaminant migration from the
HRIA DNAPL source zone. Generally, it can be expected that a one order of magnitude
reduction in contaminant mass discharge can be achieved with targeted DNAPL source treatment
with most commonly used technologies. A 90% reduction in PCE mass discharge from the high
concentration groundwater remediation target zone should be achievable based on reductions in
organic compound concentrations that were achieved at similar sites where DNAPL source
treatment was conducted (McDade et al., 2005, McGuire et al., 2006). This type of reduction
also results in significant reduction in the contaminant source strength, thereby reducing the
continued discharge of contaminants. Additionally, reductions in contaminant concentrations in
the downgradient dissolved phase plume are expected once the reduction in mass discharge from
the high concentration source zone has been achieved, although no specific goal has been
specified yet for these downgradient areas.
The use of mass discharge as a PRG is not currently a widespread practice and regulations do not
address the reduction of mass discharge as a RAO. However, there is significant utility in using
mass discharge as a PRG to evaluate DNAPL source treatment because it conveys important
information about source strength, aquifer attenuation rates, and/or areas to what extent mobile
contaminant mass is moving. In fact, the EPA points to the following reasons, among others, for
using mass discharge estimates during site characterization and remediation, as discussed in
ITRC 2010.
• "The flux [discharge] is the best estimate of the amount of contaminant leaving the
source area. This information would be needed to scale an active remedy if necessary."
• "The flux [discharge] estimate across the boundary to a receptor is the best estimate of
loading to a receptor."
In addition, mass discharge estimates are effective metrics to characterize site conditions and
assess cleanup action performance for the HRIA because of uncertainty of the contribution of
HRIA sources to mass loading to the downgradient dissolved phase contaminant plume. A
reduction in mass discharge across the 4,000 \aglL boundary will result in a greater understanding
of the relationship between the HRIA DNAPL source and the downgradient plume response that
can help future remediation decision-making. For instance, the reduction in mass discharge from
the HRIA may be sufficient to observe a desired rate of contaminant plume retraction to allow
for less-intensive cleanup to address remaining downgradient contamination and achieve long-
term ARARs within the desired timeframe (e.g., MCLs at downgradient compliance and/or
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interim performance monitoring points). Alternatively, it may be determined that contaminant
mass discharge from other sources located outside of the HRIA, but within the Site, contribute a
much greater overall mass loading to the site-wide contaminant plume than the remaining
contamination within the HRIA and thus are a priority for any additional cleanup actions as part
of the comprehensive site-wide strategy.
Achievement of this PRG would address RAO 4 as it pertains to the High Concentration
Groundwater in the HRIA. It would contribute to, but not fully achieve RAO 1.
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7.0 SUMMARY OF INTERIM CLEANUP ALTERNATIVES
This section of the Proposed Plan presents the interim cleanup alternatives that were considered
to address known sources of contamination (primarily PCE) to sediment, soil and groundwater
and reduce risks within the HRIA, and to minimize further migration of contaminated
groundwater from the HRIA to downgradient areas of the site. Doing so will also address the
principal threat waste, identified as PCE DNAPL, in the HRIA.
The cleanup alternative development process began in the Feasibility Study with identification,
screening and analysis of all known potentially applicable cleanup alternatives to address
contaminated media in each of the HRIA remediation target zones. The retained cleanup
alternatives were then combined into comprehensive cleanup alternatives using a combination of
synergetic treatment technologies that would best achieve the RAOs identified in Section 6. For
purposes of this Proposed Plan, these retained cleanup alternatives are called "Comprehensive
Technology Scenarios" or CTSs. The CTSs for each of the remediation target zones are
summarized below.
7.1 COMMON ELEMENTS ACROSS ALTERNATIVES
The common elements within each of the retained CTS alternatives, with the exception of CTS-1
(No Action), are as follows:
7.1.1 Re-route Berwick Creek
Berwick Creek would be re-routed around the areas of contamination prior to starting cleanup
actions in the HRIA. The permanence of this diversion will be made later in a decision document
selecting the final remedy for the Site.
A temporary diversion would consist of routing the creek through a 48-inch diameter high
density polyethylene (HDPE) pipe around the remediation target zones, and back into Berwick
Creek downstream of these zones. Upon completion of the cleanup action, the original creek
channel would be reconstructed and habitat restored, and the temporary diversion removed. A
permanent diversion of the creek would involve creation of a new creek channel and habitat prior
to cleanup actions in the HRIA. Habitat considerations include the planting of native vegetation
and installation of fish habitat, such as spawning gravel.
Whether reconstructing the current creek channel after cleanup actions are completed or
constructing a new creek channel prior to initiating cleanup actions, requirements that are
protective of aquatic and benthic receptors would need to be met, e.g., 0.468 mg/kg PCE based
on EPA's RSLs for protection of benthic and freshwater organisms living in Berwick Creek
sediments. The design specifications for the creek diversion, creek channel construction, and
habitat restoration would be completed in consultation with the appropriate natural resource
agencies. Diversion of Berwick Creek would be conducted during a seasonally dry period within
Washington State's in-stream work window.
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7.1.2 Institutional Controls
A variety of ICs would be implemented during and after the interim cleanup action at the HRIA.
The objectives of the ICs for the HRIA include preventing the use of HRIA groundwater for
drinking water, and requiring workers to wear protective gear.
The types of ICs that would be employed include activity and use restrictions through proprietary
(e.g., easements, covenants), and/or governmental (e.g., zoning requirements, building codes
and/or restrictions on well drilling) controls. Other ICs that could be added to the above if
warranted include information device ICs (e.g., warning signs, advisories, additional public
education, deed notices, Notices of Environmental Contamination) to inform people of the
presence of any residual contamination and the risks such contamination may pose.
Implementation, monitoring and enforcement of the ICs would be the responsibility of some
combination of property owners, local government, Ecology and/or EPA.
7.1.3 Monitoring
Sampling of surface water, sediment, soil, groundwater, and air sampling) will be performed
during and after cleanup in order to ensure protection of humans and the environment, and to
determine the effectiveness s of the interim cleanup action. Future cleanup decisions within the
HRIA will also take into account results from future OU2 investigations in order to support a
site-wide, groundwater plume management strategy.
To evaluate the mass discharge PRG for high concentration groundwater (PCE > 4,000 jig/L),
performance monitoring wells would be established. Figure 6-2 shows the proposed mass
discharge measurement plane and the wells that may be used to measure discharge relative to the
remediation target zones and the PCE contaminant plume. The location of the proposed plane
has been chosen to incorporate the following considerations:
• Near the downgradient edge of the high concentration groundwater treatment zone.
• Screened in the upper and lower zones of the shallow aquifer where groundwater
contamination is located.
Exact placement and screened intervals of the mass discharge wells may be changed once
additional data are collected during the remedial design to characterize the vertical and lateral
hydraulic system more fully. It is also important to note that groundwater samples would be
collected in wells that correspond to the mass discharge analysis and analyzed for contaminant
concentrations using standard analytical procedures. These data would be used to compare
standard analytical contaminant concentration changes as another line of evidence for mass
discharge reductions that are observed. In addition, groundwater analytical results would be used
to determine when to conduct a mass discharge assessment. For instance, if a 90% reduction in
contaminant concentrations is observed at the discharge wells, an assessment of mass discharge
may be conducted to verify corresponding reductions.
7.1.4 Five-Year Reviews
Hazardous substances are expected to stay within the HRIA above levels that allow for
unrestricted use and unlimited exposure after the interim cleanup actions is complete. As such,
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a review will be conducted at least every five years from the start of the interim cleanup action as
required by law.
7.1.5 ARARs Waiver
The Preferred Alternative, and other alternatives considered for the HRIA, were developed and
evaluated for use as an interim cleanup action as described in Section 4, "Scope and Role".
Consequently, none of the Alternatives evaluated are expected to be able to fully attain all of the
ARARs for the HRIA. The ARARs that will be attained and those that will be waived will be
specified in the Interim ROD, which is expected to include the interim action waiver provided
for in Section 121(d)(4)(A) of CERCLA. The Interim ROD will eventually be followed by a
Final ROD for the HRIA or site that will fully address compliance with all ARARs, consistent
with CERCLA, including any waivers.
7.2 UNIQUE FEATURES OF EACH CTS ALTERNATIVE
The subsections below summarize the unique features of each of the evaluated alternatives.
Please note that a specific implementation sequence of each component within CTS-2 and CTS-3
is not proposed at this time in order to allow flexibility to consider and adapt to new information
during the design phase. For example, it may be decided to initiate biological treatment before
thermal treatment because of vendor availability or the high costs associated with implementing
a thermal technology.
7.2.1 CTS-1 No Action
Evaluation of the No Action Alternative is required by law to provide a baseline against which
impacts of the various cleanup alternatives can be compared. Its inclusion is meant to help assure
that the consequences of no action are fully evaluated so that unnecessary remedial action is not
taken where no action is appropriate.
Under this alternative, no action would be taken to actively clean up the contaminated creek bed
sediment and bank surface soil, subsurface soil or groundwater, nor would monitoring of PCE
concentrations to address the associated risks to human health or the environment be conducted.
Estimated Timeframe:
• Achieve Interim Action PRGs and RAOs: N/A
Costs:4
• Capital Costs: $0
• Annual Operations & Maintenance (O&M) Costs:$0
• Total Present Worth: $0
4 See the Glossary for a definition of each type of costs.
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7.2.2 CTS-2 (EPA's Preferred Alternative)
The conceptual approach for CTS-2 is illustrated in Figure 7-1. In addition to the common
elements discussed in section 7.1, CTS-2 consists of the following components:
• Heat sediment and soil with PCE concentrations greater than 10 mg/kg.
• Excavate and dispose of remaining sediment and surface soil with PCE
concentrations greater than 10 mg/kg.
• Add organic materials to groundwater with PCE concentrations greater than 4,000
jig/L.
Heat Sediment, Surface Soil and Subsurface Soil with PCE Concentrations Greater Than 10
mg/kg PCE
Under CTS-2, in-situ thermal treatment would be used on contaminated creek bed sediment and
bank surface soil within the current creek channel, on other surface soil outside of the creek
channel, and on subsurface soil. Thermal treatment is expected to reduce PCE concentrations to
10 mg/kg to ensure removal of DNAPL. Substantial reductions in PCE DNAPL in sediment and
soil would also decrease PCE concentrations in groundwater within and downgradient of the
HRIA.
A full suite of thermal technologies (e.g., steam injection, steam extraction, electrical heating),
would be considered as part of the remedial design. Thermal treatment methods work by heating
contaminated soil and groundwater. The heat helps push up chemicals through the soil to
collection wells. The heat can also destroy or evaporate certain types of chemicals. When they
evaporate, the chemicals change into gases, which move more easily through the soil. Collection
wells capture the harmful chemicals and gases and pipe them to the ground surface for treatment.
Construction of the thermal treatment system would be accomplished using conventional
construction equipment and services, with contractors that specialize in this innovative
technology. During operation, temperature, groundwater quality, vapor emissions, and
condensate/discharge will be monitored. The total heating/treatment time is estimated to range
from six to nine months to reduce PCE concentrations to 10 mg/kg.
Excavate and Dispose of Remaining Sediment and Surface Soil with PCE Concentrations
Greater than 10 mg/kg Under CTS-2, confirmation sampling would be conducted in sediment
and soil after thermal treatment to evaluate compliance with the 10 mg/kg PCE PRG. Although it
is anticipated that that in-situ thermal treatment will be effective at reducing the high levels of
PCE found in HRIA sediment and soil, it is possible that it will not be reduced to the PRG level
in all locations. The reasons for this are varied, e.g., site geology and/or hydraulic conditions
may restrict some of the PCE from being pushed up through the heated soil to collection wells or
in some locations the starting PCE concentrations may be so high that even a 99% reduction in
concentration still leaves > 10 mg/kg in the soil. It is also possible that the results of additional
sampling find isolated "hotspots" of elevated PCE levels that would be too costly to address by
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extending the thermal treatment zone. To address these potential situations, the following actions
are proposed:
• If after thermal treatment, sediment and surface soil are found to exceed 10 mg/kg PCE,
they would be excavated and consolidated within the HRIA prior to disposal. Excavated
soils would be placed on an impermeable liner and the stockpile covered to minimize the
risk of contaminants leaking into the underlying soil until waste characterization testing
can be completed and the material is transported offsite to an approved disposal facility.
• If after thermal treatment, subsurface soil is found to exceed 10 mg/kg PCE, another
technology such as in situ biological treatment would be considered to further reduce
PCE concentrations.
If further treatment of the excavated sediment and surface soil is required prior to off-site
disposal (based on landfill restrictions), a chemical would be injected or mixed into the
contaminated materials to help destroy or "oxidize" the PCE. Oxidizing chemicals help change
harmful chemicals into harmless ones, like water, carbon dioxide and diluted hydrochloric acid.
Typical chemical oxidants include hydrogen peroxide (H202) and potassium permanganate
(KMn04). Soil sampling and testing would be required to determine the best chemical oxidant
and dosage needed to effectively reduce contaminants in the excavated material. The excavated
sediment and surface soil, whether treated on or off-site, would be loaded into dump trucks and
transported to a licensed disposal facility.
Add Organic Materials to High Concentration Groundwater
Under CTS-2, in-situ biological treatment would be used on groundwater with PCE
concentrations greater than 4,000 ng/L. Biological treatment is expected to reduce migration
(mass discharge or flux) of PCE contamination by 90% from the high concentration groundwater
(greater than 4,000 \aglL PCE) to the downgradient dissolved phase plume as quickly as
technically achievable. Residual contamination in subsurface soils would also be reduced.
Biological treatment could be conducted either before or after thermal treatment.
Biological treatment, also called bioremediation, has been described as a technology that uses
natural processes to reduce the concentration or toxicity of a hazardous substance. Microbes that
live in soil and groundwater such as bacteria or fungi, will eat certain harmful chemicals. When
microbes completely digest these chemicals, they change them into water and harmless gases
such as carbon dioxide. In order for microbes to clean up harmful chemicals, the right
temperature, nutrients, and amount of oxygen must be present in the soil and groundwater.
In order to boost or enhance this natural process, certain organic materials can be injected into
the soil and groundwater. Examples of these "amendments" include whey, lactate, emulsified
vegetable oil, and suspensions of zero-valent iron. Testing will be done during remedial design to
determine the best amendment or combination of amendments to use, and to determine where
injection wells are to be placed. This testing area would be located in the area of highest PCE
concentrations along the most downgradient boundary of the 4,000 pg/L PCE remediation target
zone.
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Estimated Timeframe:
• Achieve Interim Action PRGs and RAOs : 3 years
Costs:
• Capital Cost: $8.02 Million
• Annual Operation and Maintenance Cost: $142,000
• Total Present Worth Cost: $8.8 Million
7.2.3 CTS-3
The conceptual approach for CTS-3 is illustrated in Figure 7-2. In addition to the common
elements discussed in section 7.1, CTS-3 consists of the following components:
• Heat sediment and soil with PCE concentrations greater than 10 mg/kg.
• Excavate and dispose of remaining sediment and surface soil with PCE
concentrations greater than 10 mg/kg.
• Chemically Treat Groundwater with PCE concentrations greater than 4,000 jig/L.
Heat Sediment, Surface Soil and Subsurface Soil with PCE Concentrations Greater than 10
mg/kg
This is the same as described under CTS-2.
Excavate and Disposal of Remaining Sediment and Surface Soil with PCE Concentrations
Greater than 10 mg/kg
This is the same as described under CTS-2.
Chemically Treat High Concentration Groundwater
Under CTS-3, contaminated groundwater greater than 4,000 pg/L would be treated by injection
of a chemical oxidant (s) via wells into the subsurface soil and groundwater within the high
concentration groundwater remediation target zone. As stated under CTS-2, oxidizing chemicals
help change harmful chemicals into harmless ones, like water, carbon dioxide and diluted
hydrochloric acid. Chemical treatment is expected to reduce the migration of PCE from the
HRIA to other areas of the Site by 90%.
Estimated Timeframe:
• Achieve Interim Action PRGs and RAOs: 3 years
Costs:
• Capital Cost: $9.9 Million
• Annual Operation and Maintenance Cost: $142,000
• Total Present Worth Cost: $ 10.7 Million
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8.0 EVALUATION OF CTS ALTERNATIVES
The CTS alternatives presented in Section 7 were evaluated using seven of the nine criteria5
described in Section 121(b) of CERCLA andNCP Section 300.430(e)(9)(iii). These criteria
address statutory requirements and considerations for cleanup actions in accordance with the
NCP and additional technical and policy considerations that have proven to be important for
selecting among cleanup alternatives (EPA 1988).
This section first describes the nine criteria and the secondary assumptions used in the
evaluation. This section then provides a comparison of the CTS alternatives identifying the
relative advantages and disadvantage of the alternatives in terms of the criteria and the secondary
assumptions. A more detailed analysis of alternatives can be found in the draft FS (CDM Smith
2012).
8.1 THE NINE CRITERIA
The nine evaluation criteria are separated into three groups, as outlined in Table 8-1, that
establish a priority for evaluating each CTS alternative. Threshold criteria are standards that an
alternative must meet to be eligible for selection as a cleanup action unless an ARAR waiver is
used. Balancing criteria weigh the tradeoffs among alternatives. Modifying criteria are fully
evaluated after comments are received on the Proposed Plan; therefore, only seven of the nine
CERCLA criteria guide the comparative evaluation presented in this Proposed Plan.
8.1.1 THRESHOLD CRITERIA
The threshold criteria include:
• OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT:
This criterion evaluates whether an alternative eliminates, reduces or controls risks to
public health and the environment through treatment, engineering, or institutional
controls.
• COMPLIANCE WITH ARARS: This criterion evaluates whether an alternative meets
federal, state, and tribal environmental statutes, regulations, and other requirements that
pertain to the site, and/or whether a waiver is justified. If the evaluation indicates an
ARAR will not be met, then the basis for justifying one of the six ARAR waivers allowed
under CERCLA is discussed.
5 The last two criteria, or "Modifying Criteria," are not fully evaluated until after comments on the Proposed Plan
are received. However, EPA has coordinated with the State (Ecology) and it concurs with the Preferred Alternative
at this time.
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8.1.2 BALANCING CRITERIA
The balancing criteria include:
• LONG-TERM EFFECTIVENESS AND PERMANENCE: This criterion considers
an alternative's ability to protect human health and the environment over time.
• REDUCTION OF TOXICITY, MOBILITY, OR VOLUME THROUGH
TREATMENT: This criterion evaluates an alternative's use of treatment technologies
to reduce the harmful effects of principal contaminants (e.g., principal threat wastes),
their ability to move in the environment, and the amount of contamination present.
• SHORT-TERM EFFECTIVENESS: This criterion considers the length of time needed
to implement an alternative and the risks the alternative poses to workers, residents, and
the environment during construction and implementation of a cleanup action.
• IMPLEMENTABILITY: This criterion considers the technical and administrative
feasibility of implementing an alternative, including factors such as the availability of
goods and services
• COST: This criterion includes estimated capital, annual operation and maintenance
(O&M), periodic, and present worth costs. Costs are expected to be accurate within a
range of +50 to -30 percent.
8.1.3 MODIFYING CRITERIA
The modifying criteria include:
• STATE ACCEPTANCE: This criterion considers whether the State agrees with EPA's
analyses and recommendations.
EPA has received comments on the draft Proposed Plan from the State (Ecology) and they
concur with the preferred cleanup alternative at this time. Final assessment of State concerns will
be completed after comments on the Proposed Plan have been received by EPA and addressed in
the interim ROD.
• COMMUNITY ACCEPTANCE: This criterion considers whether the local community
agrees with EPA's analyses and the preferred alternative.
Community acceptance of the preferred alternative will be evaluated after the public comment
period ends. Comments received during that time will be included and responded to in a
Responsiveness Summary section of the interim ROD.
8.2 COMPARATIVE ANALYSIS OF CTS ALTERNATIVES
In this subsection, the CTS alternatives discussed in Section 7 are comparatively evaluated
against the two threshold criteria and five balancing criteria. The results of this evaluation are
presented in Table 8-2 and discussed below.
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8.2.1 Overall Protection of Human Health and the Environment
Protection of human health and the environment is one of two threshold criteria that each
alternative must meet in order to be further evaluated as a potential cleanup action (the other
being compliance with ARARs).
The CTS-1 alternative (No Action) would not address any risks and therefore is not protective of
human health and the environment and does not achieve this criterion.
The CTS-2 and CTS-3 alternatives would achieve the criterion of overall protection of human
health and the environment within the scope of the interim action by removing or substantially
reducing the amount of contaminant mass, including DNAPL, and implementation of ICs to
prevent the use of HRIA groundwater for drinking, and require workers to wear protective gear.
A reduction in contaminant mass would also result in a reduction of source material and
contaminant migration to areas downgradient of the HRIA, thereby increasing the likelihood of
achieving this criterion across more areas of the Hamilton/Labree site.
8.2.3 Compliance with ARARs
Compliance with ARARs is the second of the two threshold criteria that each alternative must
meet in order to be further evaluated as a potential cleanup action, unless one of the ARARs is
waived.
The No Action alternative (CTS-1) does not implement any action and therefore will not achieve
this criterion. Because CTS-1 does not meet either of the threshold criteria (overall protection
of human health and the environment, and compliance with ARARs), it will not be further
evaluated as an alternative.
Both CTS-2 and CTS-3 would comply with the MTCA Method B cleanup level for human direct
contact exposure with soils, which requires cleanups to attain the lxlO"6 risk level for protection
of human direct contact exposure. The PCE concentration which equates to a lxlO"6 risk from
direct contact assuming residential use is 22 mg/kg, industrial/commercial use is 110 mg/kg, and
recreational use within the HRIA creek bed sediments and bank surface soils is 924 mg/kg. The
soil PRG for both CTS-2 and CTS-3 is no single sample that exceeds 10 mg/kg PCE which far
exceeds the 1 x 10"6 protection level.
CTS-2 and CTS-3 would also both meet the 10 mg/kg PCE level for protection of terrestrial
ecological receptors, e.g., short-tailed shrew, from ingestion and inhalation of surface soil in
burrow air, and would meet EPA's RSL of 0.468 mg/kg PCE for protection of benthic and
freshwater organisms in creek bed sediment and bank surface soil when the impacted creek
channel is relocated or reconstructed.
Both CTS-2 and CTS-3 include institutional controls to prevent human exposure to groundwater
above the Federal and State MCL of 5 |ig/L, and cleanup actions that would help prevent further
migration of contaminated groundwater to areas downgradient of the HRIA. Since this will be an
interim action which is limited in scope, neither alternative is expected to achieve MCLs and
restore groundwater to its most beneficial use (as a drinking water source) across the entire Site.
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Therefore, the selected interim cleanup action would include a waiver, based on the interim
action, of the MCL ARAR.
8.2.4 Long-Term Effectiveness and Permanence
Long-term effectiveness and permanence is the first of the five balancing criteria which weigh
the tradeoffs between among alternatives.
CTS-2 and CTS-3 would both provide a high degree of long-term effectiveness and permanence
by substantially reducing sediment, soil and groundwater contaminant concentrations and mass,
including DNAPL which is a principal threat waste, from the HRIA. These alternatives would
result in a reduction in source material, and contaminant mass discharge to areas downgradient
from the HRIA over the long term.
The valley in which the Hamilton/Labree site is located is prone to flooding every few years
which could negatively impact the effectiveness of equipment employed for long-term treatment.
The treatment technologies considered for both CTS-2 and CTS-3, however, would be equally
impacted by these events over the short- and long-terms.
8.2.5 Reduction of Toxicity, Mobility, or Volume through Treatment
Reduction of toxicity, mobility, or volume through treatment is the second of the five balancing
criteria.
CTS-2 and CTS-3 would both provide a high level of reduction in toxicity, mobility, or volume
of contaminated materials, and satisfy the statutory preferences for treatment and treatment of
principal waste threats. All of the evaluated alternatives would be effective at reducing
contaminant mass and discharge and result in a substantial reduction in contaminant mobility.
Toxicity would be decreased by lowering PCE concentrations in the sediment, soil and
groundwater.
One trade-off to be considered when evaluating these two alternatives against this criterion is the
use of amendments to enhance reduction of contaminants. Under CTS-2, enhanced
bioremediation will entail injection of non-toxic food grade materials into the subsurface soil and
groundwater. Under CTS-3, chemical oxidants will be injected. Some chemical oxidants can
create toxic by-products which may increase toxicity in the short-run; however, the potential for
this to happen would be mitigated during the design of this alternative. Different chemical
oxidants will be evaluated in bench scale and/or pilot treatability studies to evaluate
performance, including creation of toxic by-products and those products tracked over time.
Oxidants will be selected based on the ability to achieve PRGs and minimize formation of
undesirable by-products.
8.2.6 Short-Term Effectiveness
Short-term effectiveness is the third of the five balancing criteria.
The estimated time to achieve RAOs under CTS-2 is 3 years. The estimated time to achieve
RAOs under CTS-3 is also 3 years. Although there are a number of issues that may impact the
construction and cleanup schedule and achievement of RAOs, the first priority is to ensure the
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schedule is not delayed because of the State of Washington's "in-stream" work window. In-
stream work windows have been established for all waters of the state of Washington. These are
in place to protect fish species at critical life stages. For Berwick Creek, the in-stream work
window is June 15 to September 30. It may be possible, however, to obtain a waiver from the
State in order to work outside the work window. If the work window is missed and a waiver
cannot be obtained, the project will be delayed from the start since Berwick Creek needs to be
relocated prior to initiating any other activities.
The community around the site will not be subject to significant risks associated with the cleanup
actions under CTS-2 or CTS-3. Potential risks to the community can be mitigated by preventing
the use of HRIA groundwater for drinking, Berwick Creek for swimming, through the use of
access controls and information devices (e.g., fences and posted warning signs).
The CTS-2 and CTS-3 alternatives both involve treatment, and possible excavation of
contaminated materials within the HRIA. These activities could pose moderately high risks to
on-site cleanup workers. Treatment involves placement of delivery systems for "injection" of
thermal, chemical or biological substances into soil and groundwater, and collection of vapors.
This poses physical risks, as well as direct contact and inhalation risks from contaminants.
Digging and working in a trench, such as when relocating or reconstructing the Berwick Creek
channel or installing horizontal soil vapor extraction wells for thermal treatment, poses an
increased inhalation risk from volatilization of contaminants from the soil and shallow
groundwater table. Additional short-term issues include increased physical risks, noise levels and
fugitive dust emissions associated with the use of heavy equipment for excavation and/or
disposal of materials. Controls such as requiring cleanup workers to wear Personal Protection
Equipment (PPE) to include air monitoring devices, minimizing the exposed work area, working
in cooler weather, using standard construction practices such as dust suppression with water,
foam or a vacuum manifold to capture emissions, covering truck loads that are transported off
the site, using conventional traffic controls to minimize accidents, and effectively capturing
vapors created during treatment would be used to minimize air pollutants and risks to cleanup
workers.
Both CTS-2 and CTS-3 include the use of a thermal technology for treating contaminated
sediment and soil. Thermal technologies require significantly large amounts of energy compared
to other treatment technologies, which can drive up project costs in the short-term. In addition, a
rapid, sustained increase in energy costs would increase overall project costs. Thermal treatment,
however, is particularly useful on DNAPLs. By using a thermal treatment technology, DNAPL
mass is substantially reduced within a relatively short time period. A secondary benefit to
thermal is that the warmed sediment and soil can enhance bioremediation in groundwater as is
being proposed under CTS-2. To combat thermal energy impacts, the thermal treatment area can
be minimized to focus only on DNAPL-impacted sediment and soils, energy efficient equipment
can be used to minimize energy consumption, and alternative fuels could be used to minimize
greenhouse gas emissions. In addition, renewable energy sources, such as solar panels, could be
used to help power treatment or auxiliary systems.
Short-term issues and impacts also exist with whatever technology is used in treating the high
concentration groundwater remediation target zone. CTS-2 proposes the use of food-grade
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amendments such emulsified vegetable oil, so negative impacts to drinking water wells and the
environment are not a large concern. In contrast, under CTS-3, chemical treatment within the
groundwater remediation target zone is proposed. Injection of certain chemicals may produce
unfavorable byproducts such as manganese oxide which could be harmful to human health and
the environment. This risk could be mitigated, however, during design. As noted in Section
8.2.5, different chemical oxidants will be evaluated in bench scale and/or pilot treatability and
oxidants will be selected based on the ability to achieve PRGs and minimize formation of
undesirable by-products.
8.2.7 Implementability
Implementability is the fourth of the five balancing criteria:
As stated above, the use of thermal technology to treat contaminated sediment and soils is
proposed in both CTS-2 and CTS-3 alternatives. Using a thermal technology would be
technically and administratively implementable; however, very few vendors are able to provide
the proprietary technology needed for this type of treatment. On the other hand, those that are
available are very experienced at using this innovate technology to effectively reduce
contaminants, including DNAPL. Using a thermal treatment technology would potentially
increase the volatilization of contaminants; therefore, installing an effective vapor recovery
system is essential. Installing and implementing such a system, however, may be challenging due
to the impermeable silt "cap" below Berwick Creek and the shallow groundwater table across the
HRIA. This may necessitate the installation of a series of trenches containing horizontal soil
vapor extraction wells which are more expensive to install than the more common vertical wells.
The regulatory and substantive permitting requirements associated with installation of electrode
or soil vapor extraction wells, laying piping, constructing the treatment system, and securing
approval for air emissions are considered to be moderately intensive. Heat retention and transport
within and downgradient of the target treatment volume are also uncertain. Impacts on heat
transfer to Berwick Creek should be considered and evaluated to minimize any undesirable
impacts. A pilot test may be necessary prior to full-scale implementation of thermal treatment to
mitigate these issues.
In regards to the high concentration groundwater remediation zone, the enhanced bioremediation
included in CTS-2 is relatively standard and several contractors are available that have
experience with their installations. Treatment of volatile contaminants like PCE in groundwater
using enhanced bioremediation is a proven technology. However, to facilitate the proper
application of the technology, the installation may need to proceed in phases in order to obtain
key engineering design parameters (e.g., feasible injection rates, preferential pathways, area of
influence from an injection point). The results of the first phase would be used to help guide
subsequent phases.
The chemical treatment technology included as part of CTS-3 is well established and can be
implemented at the HRIA within the high concentration groundwater remediation target zone.
Chemical oxidants would be delivered to the subsurface using readily available, conventional
construction equipment. Testing would be required to determine the dose of chemical oxidant
required. Testing may also be necessary prior to full scale implementation in order to obtain key
engineering design parameters (e.g., feasible injection rates, preferential pathways, area of
influence from an injection point, longevity of oxidant).
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Off-site disposal at a licensed disposal facility of treated or non-treated residual contaminated
sediment and soil is considered under both CTS-2 and CTS-3. Delays in the project and
increased costs could be realized if there is not an appropriate disposal facility relatively close to
the Site.
8.2.8 Cost
Cost is the last of the five balancing criteria:
CTS-2 and CTS-3 both include treatment that would be completed within 3 years and monitoring
for a 30-year period. The present value cost for CTS-2 is estimated at $8.8 million. The capital
cost for CTS-2 is $8.02 million and the annual O&M cost is $142,000. The present value cost for
CTS-3 is estimated at $10.7 million. The capital cost for CTS-3 is $9.9 million and the annual
O&M cost is $142,000.
As stated earlier in this section, these cost estimates are expected to be accurate within a range of
+50 to - 30 percent. Future O&M and periodic costs are included and reduced by the appropriate
present value discount rate as outlined in A Guide to Developing and Documenting Cost
Estimates during the Feasibility Study (EPA 2000). Per the guidance, the present value analysis
was performed on remedial alternatives using a 7 percent discount (interest) rate over the period
of evaluation for each alternative. Inflation and depreciation were not considered in preparing the
present value costs.
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9.0 PREFERRED ALTERNATIVE FOR OU1
This section presents EPA's Preferred Alternative. The State of Washington supports EPA's
Preferred Alternative at this time; however, EPA will seek formal State concurrence after EPA
and the State consider other government agency and public comments received on this Proposed
Plan. The Preferred Alternative can change in response to comments or if new information
becomes available before the interim cleanup action is selected in the Interim ROD.
9.1 A PHASED APPROACH
EPA intends to address contamination at the Site through a phased approach beginning with an
interim cleanup action in the HRIA. A phased approach to site cleanup is the most appropriate
when site characterization is not yet complete or when site data are not sufficient to develop and
evaluate cleanup alternatives to address risks posed by the entire site or to determine long-term
objectives for the entire site (e.g., restoring groundwater to safe drinking water levels). There
appears to be other contamination sources at the Site outside of the HRIA; however, additional
site-wide data collection and evaluation is needed to develop, select and implement other cleanup
action(s) for the Site that will achieve long-term protection of human health and the
environment. The proposed interim cleanup action for the HRIA presented in this Proposed Plan
is necessary to address the known sources of contamination to sediment, soil and groundwater
within the HRIA and the most immediate risks posed by these sources, and to minimize further
migration of contaminated groundwater from HRIA to downgradient areas.
9.2 THE PREFERRED ALTERNATIVE
EPA has identified Alternative CTS-2 as the Preferred Alternative for the interim cleanup action
at the HRIA. The Preferred Alternative includes the following components:
• Re-route Berwick Creek around areas of contamination.
•S Re-routing about 200 feet of Berwick Creek around the areas of contamination in the
HRIA will help protect wildlife, fish and other organisms that live in or visit the
creek channel from possible negative impacts caused by cleanup activities. The creek
will be re-routed to a location within the HRIA where it may remain permanently.
The creek channel (bed and banks) would be designed to meet requirements that
protect ecological inhabitants, e.g., less than 0.468 milligrams per kilogram [mg/kg]
PCE, based on EPA's benchmark for protection of organisms living in freshwater
sediments.
• Heat sediment and soil with PCE concentrations greater than 10 mg/kg.
•S Increasing the temperature by heating the sediment and soil would remove
contaminant mass and reduce PCE concentrations to 10 mg/kg.
• Excavate and dispose of remaining sediment and surface soil with PCE
concentrations greater than 10 mg/kg.
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¦S If heating of the sediment and soil is not successful in reducing PCE
contamination to 10 mg/kg, the sediment and surface soil will be excavated.
^ The excavated sediment and surface soil would be consolidated within the HRIA
and treated with a chemical, such as potassium permanganate if necessary to meet
disposal requirements or they may be treated at an off-site, licensed disposal
facility.
• Add organic materials to groundwater with PCE concentrations greater than
4,000 micrograms per liter (jig/L).
•S Injecting organic material such as emulsified vegetable oil into groundwater with
PCE concentrations greater than 4,000 |ig/L would enhance the biological
breakdown of PCE and reduce the migration of PCE from the HRIA to other areas
of the Site by 90%.
• Institutional controls
S Institutional controls or ICs will be implemented during and after the interim
cleanup action. ICs are non-engineered instruments, such as legal restrictions,
covenants or easements on property, and governmental and/or administrative
controls that as part of this interim action would be used to help prevent or
minimize the potential for human exposure to hazardous substances, pollutants or
contaminants. The objectives of the ICs for the HRIA include preventing the use
of groundwater for drinking water and requiring workers to wear protective gear.
• Monitoring
•S Sampling of surface water, sediment, soil, groundwater, and air sampling will be
performed during and after cleanup in order to ensure protection of humans and
the environment, and to determine the effectiveness of the interim cleanup action.
9.3 BENEFITS OF PROPOSED PREFERRED ALTERNATIVE
Based on the information currently available, EPA believes the Proposed Preferred Alternative
can achieve the RAOs and PRGs identified in Section 6 of this Proposed Plan, and can meet the
two threshold criteria, within the scope of this interim action, and provide the best balance of
tradeoffs among the other alternatives with respect to the balancing and modifying criteria as
evaluated in Section 8. EPA also expects the Preferred Alternative to be cost effective, utilize
permanent solutions and alternative treatment technologies to the maximum extent practicable
and, satisfy the preference for treatment as a principal element. The Preferred Alternative is
expected to attain a level of protection for risks to human health and the environment that is
commensurate to the scope of the selected interim cleanup action to be identified in the Interim
ROD, and will not exacerbate conditions at the HRIA or Hamilton-Labree Site as a whole.
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10.0 COMMUNITY PARTICIPATION
Community engagement plays a key role in the process of developing an effective cleanup plan
for the Hamilton Road Impacted Area. Public comments can help shape EPA's cleanup
decisions. EPA will continue to provide information regarding the cleanup activities of the
Hamilton/Labree Roads Groundwater Contamination Superfund Site to the public through the
Administrative Record for the Site, site updates, newsletters, direct mailings, announcements
published in the Chehalis Chronicle, public meetings, and through its Hamilton/Labree Roads
Superfund website which may be accessed at:
http://yosemite.epa.gov/R10/cleanup.nsf/sites/HLabree
EPA and Ecology encourage the public to gain a more comprehensive understanding of the Site
and proposed cleanup activities. Details about the public meeting and instructions for providing
comments on this Proposed Plan are provided in Section 1.3 of this Proposed Plan. Section 14.0
contains a blank comment form to facilitate submission of comments.
For additional information on this project, please contact:
Ms. Tamara Langton
US EPA Region 10
1200 Sixth Ave, Suite 900
Office of Environmental Cleanup, ECL-113
Seattle, WA98101
(T) 206-553-2709
(F) 206-553-0124
langton.tamara@epa.gov (For emailed comments, please put "HRIA Proposed Plan" in the
subject line.)
Documents referred to in this Proposed Plan may be found in the Administrative Record, which
is available for public review at the following locations:
Vernetta Smith Chehalis Timberland Library
76 N.E. Park Street
Chehalis, WA 98532
(360) 748-3301
EPA Region 10
Superfund Records Center
1200 Sixth Avenue, Ste. 900 (ECL-076)
Seattle, WA98101
(206)553-4494
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11.0 LIST OF ACRONYMS USED IN PROPOSED PLAN
> Greater Than
< Less Than
% Percent
AES Architect and Engineering Services
AOC Administrative Order on Consent
ARARs Applicable or Relevant and Appropriate Requirements
bgs Below Ground Surface
BLRA Baseline Risk assessment
CDM Smith CDM Federal Programs Corporation
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
CFR Code of Federal Regulations
CG Commercial General
cis-l,2-DCE cis-l,2-Dichloroethene
COCs Contaminants of Concern
CPOCs Conditional Points of Compliance
CSM Conceptual Site Model
CTS Comprehensive Treatment Scenario
cy Cubic Yards
DCE Dichloroethene
DNAPL Dense Non-Aqueous Phase Liquid
DPT Direct-Push Technology
Ecology Washington State Department of Ecology
E&E Ecology & Environment
EE/CA Engineering Evaluation/Cost Analysis
EPA U. S. Environmental Protection Agency
ERH Electrical Resistance Heating
ERT Emergency Response Team
°F Degrees Fahrenheit
Farallon Farallon Consulting, L.L.C.
FS Feasibility Study
FRTR Federal Remediation Technologies Roundtable
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ft/ft Foot per Foot
GRA General Response Action
H2O2 Hydrogen Peroxide
HC High Concentration Groundwater
HDPE High Density Polyethylene
HRIA Hamilton Road Impacted Area
1-5 Interstate 5
ICs Institutional Controls
IROD Interim Record of Decision
ISCO In-Situ Chemical Oxidation
kg/g Kilograms per Gram
kg/ft3 Kilograms per Cubic Foot
KMn04 Potassium Permanganate
lb/ft3 Pounds per Cubic Foot
LC Lower Concentration Groundwater
LDRs Land Disposal Restrictions
LCDPH Lewis County Department of Public Health
MCL Maximum Contaminant Level
Md Mass Discharge
|ig/L Micrograms per Liter
|ig/kg Micrograms per Kilogram
|ig/m3 Micrograms per cubic Meter
mg/kg Milligrams per Kilogram
MSL Mean Sea Level
MTCA Model Toxics Control Act
MVS Mining Visualization Systems
NAPL Non-Aqueous Phase Liquid
NCP National Oil and Hazardous Substances Pollution Contingency Plan
NPL National Priorities List
O&M Operations and Maintenance
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OU1 Operable Unit 1
OU2 Operable Unit 2
PCE Tetrachloroethene (also known as Perchloroethylene)
PPE Personal Protective Equipment
ppm-v Parts per Million by Volume
RAO Remedial Action Objective
RDD Rural Development District
RI Remedial Investigation
ROD Record of Decision
RSL Regional Screening Level
Site Hamilton/Labree Roads Groundwater Contamination Superfund Site
START EPA Superfund Technical Assistance and Response Team
TBC To Be Considered
TCE Trichloroethene
TCLP Toxicity Characteristic Leaching Procedure
TSCA Toxic Substances Control Act
UGA Urban Growth Area
URS URS Group, Inc.
USC United States Code
VOCs Volatile Organic Compounds
WDOH Washington State Department of Health
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12.0 GLOSSARY
Administrative Record: Material documenting EPA's selection of cleanup remedies at
Superfund sites, usually placed in the Information Repository near the site.
Alluvium: A general term for clay, silt, sand, gravel or similar material deposited by a stream or
other body of running water.
Ambient: Existing or present on all sides; surrounding.
Ambient Air: Any unconfined portion of the atmosphere: open air, surrounding air.
Applicable or Relevant and Appropriate Requirements (ARARs): Refers to federal and state
requirements a selected remedy must attain, which vary from site to site.
Aquifer: A geologic formation, group of formations, or part of a formation that is capable of
yielding a significant amount of water to a well or spring.
Aquitard: A geological formation that may contain groundwater but is not capable of
transmitting significant quantities of groundwater under normal hydraulic gradients. An aquitard
may prevent different aquifers from mixing.
Artesian: Water in an aquifer that is confined and held under positive pressure by impermeable
geological formations. This causes the water level in a well to rise to a level higher than the
water level in the top of the aquifer, sometimes even reaching the ground surface.
Balancing Criteria: Criteria 3-7 of the nine criteria used to evaluate and compare remedial
alternatives developed in a Feasibility Study. The balancing criteria are long-term effectiveness
and permanence, reduction of toxicity, mobility, or volume through treatment, short-term
effectiveness, implementability, and cost.
Baseline Risk Assessment (BLRA): A qualitative and quantitative evaluation performed in an
effort to define the risk posed to human health and the environment by the presence or potential
presence and use of specific pollutants.
Below ground surface (bgs): The depth at which contamination, groundwater, or any other
object of interest is found below the surface of the ground.
Benthic: Of, relating to, or occurring at the bottom of a body of water.
Characterization: The use of scientific techniques to determine properties and compositions of
something.
Commercial General (CG): A City of Chehalis zoning classification. The intent of the CG
zone is to provide an area for development of general commercial businesses, offices, retail
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stores, institutions, and similar commercial uses, with zoning controls designed to address
significant impacts that may occur with such development.
Commingled: Blended or mixed.
Compliance: Meeting or exceeding requirements of relevant laws and regulations.
Comprehensive Environmental Response, Compensation and Liability Act (CERCLA or
Superfund): A federal law passed in 1980 and amended in 1986 by the Superfund Amendments
and Reauthorization Act (SARA); the Act created a trust fund, known as Superfund, to
investigate and cleanup abandoned or uncontrolled hazardous waste sites.
Comprehensive Technology Scenario (CTS) Alternative: A clean-up approach that includes
multiple components to address contamination in affected media and/or locations.
Confined Aquifer: An aquifer in which groundwater is confined between impermeable
geologic formations, such that the pressure is significantly greater than atmospheric pressure and
causes artesian conditions.
Contaminant of Concern (COCs): Those chemicals detected in soil, sediment, water or air that
could pose an unacceptable risk to human health.
Costs (capital, annual operation and maintenance (O&M), periodic, and present worth
costs): Criterion for evaluation of alternatives. Includes estimated costs: capital, annual
operation and maintenance (O&M), periodic, and present worth. Costs are expected to be
accurate within a range of +50 to -30 percent.
• Capital costs: Are those expenditures that are required to construct a remedial action.
They are exclusive of costs required to operate or maintain the action throughout its
lifetime. Capital costs consist primarily of expenditures initially incurred to build or
install the remedial action (e.g., construction of a water treatment system and related site
work). Capital costs include all labor, equipment, and material costs (including contractor
markups, such as overhead and profit) associated with activities, such as
mobilization/demobilization; monitoring site work; installation of extraction,
containment, or treatment systems; and disposal. Capital costs also include expenditures
for professional/technical services that are necessary to support construction of the
remedial action.
• Annual O&M costs: Are those post-construction costs necessary to ensure or verify the
continued effectiveness of a remedial action. These costs are estimated mostly on an
annual basis. Annual O&M costs include all labor, equipment, and material costs
(including contractor markups, such as overhead and profit) associated with activities,
such as monitoring; operating and maintaining extraction, containment, or treatment
systems; and disposal. Annual O&M costs also include expenditures for
professional/technical services necessary to support O&M activities.
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• Periodic costs: Are those costs that occur only once every few years (e.g., 5-year
reviews, equipment replacement) or expenditures that occur only once during the entire
O&M period or remedial timeframe (e.g., site closeout, remedy failure/replacement).
These costs may be either capital or O&M costs but, because of their periodic nature, it is
more practical to consider them separately from other capital or O&M costs in the
estimating process.
• Present Worth Costs: Provides the basis for cost comparison between alternatives. The
present value cost represents the amount of money that, if invested in the initial year of
the remedial action at a given rate, would provide the funds required to make future
payments to cover all costs associated with the remedial action over its planned life. The
present value analysis was performed on remedial alternatives using a 7 percent discount
(interest) rate over the period of evaluation for each alternative. Inflation and depreciation
were not considered in preparing the present value costs.
Deep Aquifer: A deeper aquifer underlies the Site and is separated from the shallow aquifer by
a silt and clay aquitard. The deeper aquifer occurs at depths greater than 150 feet bgs in the area
of the HRIA. Sampling results for the deeper aquifer wells have historically been "non-detect"
for PCE, except for three isolated detections.
Dense Nonaqueous Phase Liquid (DNAPL): Non-aqueous phase liquids, such as chlorinated
hydrocarbon solvents, with a specific gravity greater than 1.0 that sink through the water column
until they reach a confining layer. Because they are at the bottom of aquifers instead of floating
on the water table, typical monitoring wells do not indicate their presence.
Downgradient: The direction that groundwater flows; similar to "downstream" for surface
water.
Engineering Controls: Containment and/or treatment systems that are designed and
constructed to prevent or limit the movement of or exposure to hazardous substances. An
example of an engineering control is a fence.
Excavation: The act of cutting, scooping, or digging out a part of a solid mass.
Exposure Route: Path for contaminants to reach people either working or residing near a site or
ecological receptors living at or near the site.
Extraction: The process used to remove groundwater through a well.
Feasibility Study (FS): An analysis of remediation alternatives often with a proposed or
recommended Alternative. For cleanup of a Superfund site, the FS usually starts shortly after the
Remedial Investigation (RI) is underway.
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Fecal Coliform: Bacteria found in the intestinal tracts of mammals. Their presence in water or
sludge is an indicator of pollution and possible contamination by pathogens (e.g., bacteria,
viruses, or parasites that can cause disease in humans, animals and plants).
Fugitive Dust: Particles lifted into the ambient air caused by human-made and natural activities
such as the movement of soil, vehicles, equipment, blasting, and wind. This excludes particulate
matter emitted directly from the exhaust of motor vehicles and other internal combustion
engines, from portable brazing, soldering, or welding equipment, and from pile drivers.
Glaciofluvial Deposits: Material moved by glaciers and subsequently sorted and deposited by
streams flowing from the melting ice.
Groundwater: The supply of fresh water found beneath the Earth's surface (usually aquifers)
which is often used for supplying wells and springs.
Hazard Index: The summation of the hazard quotients for all chemicals to which an
individual is exposed. A hazard index value of 1.0 or less than 1.0 indicates that no adverse
human health effects (non-cancer) are expected to occur.
Hazard Quotient: The ratio of estimated site-specific exposure to a single chemical from a site
over a specified period to the estimated daily exposure level, at which no adverse health effects
are likely to occur. A typical acceptable range for a hazard quotient is less than 1.0.
Human Health Risk Assessment (HHRA): The investigation to determine the likelihood that a
given exposure or series of exposures may have damaged or will damage the health of human
beings.
Hydraulic: Of or related to water or other liquid in motion; operated, moved or affected by
means of water.
Hydraulic Conductivity: The rate at which water can move through a permeable medium, like
native soil, gravel, silt, etc.
Information Repository: A library or other location where documents and data related to a
Superfund project are placed to allow the public access to the material.
In Situ: In the natural or original position; in place.
Institutional Controls: Restriction that prevents the owner to inappropriately develop the
property. The restriction could be implemented as a "Deed Restriction" and is designed to
prevent harm to workers (i.e., those digging in the area) or restrict potential residential
development.
Isoconcentration: More than one sample point exhibiting the same concentration.
Isocontour: The line or area represented by an isoconcentration.
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Lacustrine: Pertaining to, produced by, or inhabiting a lake.
Lenses: Deposit that are thick in the middle and thin at the edges,
Mass Flux: Mass of contaminant per unit time migrating from source area.
Maximum Contaminant Level (MCL): The maximum permissible level of contaminant in
water that may be delivered to any user of a public water system.
Medium/Media: Environmental category (e.g., surface water, groundwater, soil, air) in which
contaminants may be present and may migrate.
Miocene: Noting or pertaining to a period of the geologic time scale from 25 million to 5.3
million years ago
Migration: T he movement of a contaminant (or anything else) from one location or media to
another.
Modifying Criteria: Criteria 8 and 9 of the nine criteria used to evaluate and compare remedial
alternatives developed in a Feasibility Study. The modifying criteria are state (and/or tribal)
acceptance and community acceptance.
National Oil and Hazardous Substances Pollution Contingency Plan (National Contingency
Plan or NCP): Federal regulations for Superfund site cleanups and responses to oil and other
spills into surface waters or elsewhere.
National Priorities List (NPL): EPA's list of priority hazardous waste sites that are eligible to
receive federal money for response under Superfund.
Nine criteria: The criteria in the NCP used to evaluate and compare remedial alternatives
developed in a Feasibility Study. The nine criteria are overall protectiveness of human health
and the environment, compliance with ARARs, long-term effectiveness and permanence,
reduction of toxicity, mobility, and volume through treatment, short-term effectiveness,
implementability, cost, state (and/or tribal) acceptance, and community acceptance.
One Order of Magnitude: A range of magnitude extending from some value to ten times that
value.
Operable Unit (OU): Different areas of a remediation project. Often a Superfund site is divided
into phases to better address different pathways or areas of contamination.
Operation and Maintenance (O&M): Activities conducted at NPL sites after cleanup
remedies have been constructed to ensure that they are properly functioning.
Parcel: A piece of land.
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Pathway: The physical course a contaminant takes from its source to gain exposure to
organisms.
Permeability: The rate at which liquids pass through soil or other materials in a specified
direction.
Permeable: Capable of being permeated or penetrated, especially by liquids or gases. Allowing
liquids or gases to pass through.
Preliminary Remediation Goal (PRG): A goal that combines current human health toxicity
values with standard exposure factors to estimate contaminant concentrations in environmental
media (soil, air, and water) that are considered by EPA to be health protective of human
exposures over a lifetime.
Proposed Alternative: The remedial alternative proposed by the EPA in a Proposed Plan using
the nine criteria in the NCP.
Proposed Plan: Superfund public participation fact sheet that summarizes the preferred
cleanup strategy, the rationale, and the Remedial Investigation/Feasibility Study (RI/FS).
Record of Decision (ROD): A public document describing EPA's rationale for selection of a
Superfund cleanup alternative.
Regional Screening Level (RSL): Risk-based screening levels, calculated using the latest
toxicity values, default exposure assumptions and physical and chemical properties
Remedial Design (RD): The Superfund cleanup phase prior to Remedial Action that primarily
consists of the development of engineering plans and specifications for a cleanup, but may
include further sampling or other investigatory tasks to resolve uncertainties and/or refine
cleanup actions.
Remedial Investigation (RI): An in-depth study including sampling and analyses to determine
the nature and extent of contamination at a Superfund site, and establish criteria to support the
analyses of alternatives in the succeeding FS.
Remedial Investigation/Feasibility Study (RI/FS): A two-part investigation conducted to fully
assess the nature and extent of the release, or threat of release, of hazardous substances,
pollutants, or contaminants, and to identify alternatives for cleanup. The Remedial Investigation
gathers the necessary data to support the corresponding Feasibility Study.
Remediation Target Zones: Specific area and media within the HRIA to be cleaned up.
Residual Source Area: Contamination remaining from the dumping or spill of PCE into
Berwick Creek that can continue to act as a source of contamination to downgradient areas of the
site.
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Semi-confined Aquifer: An aquifer partially confined by soil layers of low permeability
through which recharge and discharge can still occur.
Shallow Aquifer: Groundwater that occurs between approximately 5 feet and 50 feet bgs at the
HRIA. Contamination at the HRIA is found in this zone.
Solubility: The ability of a substance to dissolve. In the process of dissolving, the substance that
is being dissolved is called a solute and the substance in which the solute is dissolved is called a
solvent. A mixture of solute and solvent is called a solution.
Solubility Limit: The amount of solute a solvent can hold; the maximum amount of solute that
can dissolve in the solvent under set conditions (temperature and pressure).
Solute: A substance dissolved in another substance, usually the component of a solution present
in the lesser amount.
Solvent: A substance in which another substance is dissolved, forming a solution.
Sorb: To take up and hold.
Stratification: Layered.
Stratigraphy: The study of original succession and age of beds, layers and zones of rock.
Superfund: A term for the hazardous waste cleanup law (CERCLA), also the EPA program that
implements that law.
Surficial: Of or relating to a surface.
Terrestrial: Living or growing on land, rather than in the sea or the air.
Threshold Criteria: Criteria 1 and 2 of the nine criteria used to evaluate and compare remedial
alternatives developed in a Feasibility Study (FS). Threshold criteria are overall protection of
human health and the environment and compliance with ARARs. Alternatives that do not meet
both threshold criteria are not carried forward as viable alternative in a FS.
Unconfined Aquifer: An aquifer containing water that is not under pressure; the water level in
a well is the same as the water table beyond the well.
Vapor Intrusion: Process in which chemical vapors from contaminated soil or groundwater
affect the indoor air quality in a building. Contaminated soil or groundwater can emit vapors that
spread to areas occupied by buildings. Vapors can enter the buildings through cracks in
basements, foundations, sewer lines, and any other type of opening.
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Volatile Organic Compounds (VOCs): Volatile organic compounds, or VOCs are organic
chemical compounds whose composition makes it possible for them to evaporate under normal
atmospheric conditions of temperature and pressure.
Water Table Aquifer: An unconfined Aquifer.
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13.0 REFERENCES
CDM Smith. 201 la. Draft Final Remedial Investigation Report Hamilton/Labree Roads
Groundwater Contamination Superfund Site. September 2011.
201 lb. Draft Final Baseline Risk Assessment Report Hamilton/Labree Roads
Groundwater Contamination Superfund Site. September 2011.
2012. Draft Final Feasibility Study Report Hamilton/Labree Roads Groundwater
Contamination Superfund Site: Operable Unit 1 Hamilton Road Impacted Area. September 2012.
Dames & Moore, Inc. 1994. Groundwater Resources Investigation for Ecology Groundwater
Right Application No. G2-29004. Prepared for Chehalis Power, Inc. Chehalis, Washington. July
7, 1994.
Ecology and Environment, Inc. (E&E). 2000. Removal Assessment Report, Hamilton-Labree
Site, Chehalis, Washington. Prepared for U SEP A Region 10 under START Contract 68-W6-
0008. TDD: 00-01-0015. Seattle, Washington. December 2000.
2001. Hamilton-Labree Phase III Removal Assessment Report, Chehalis, Washington.
Prepared for USEPA Region 10 under START-2 Contract 68-S0-01-01. TDD: 01-01-0010.
Seattle, Washington. April 2001.
2002. Hamilton-Labree Phase IV Removal Assessment, Chehalis, Washington. Prepared
for USEPA Region 10 under START-2 Contract 68-S0-01-01. TDD: 01-09-0006. Seattle,
Washington. January 2002.
2003. Hamilton-Labree Removal Action Report, Chehalis, Washington. Prepared for
USEPA Region 10 under START-2 Contract 68-S0-01-01. TDD: 02-07-0002. Seattle,
Washington. May 2003.
Farallon. 2002. Phase I Investigation Work Plan, Hamilton/Labree Roads Groundwater
Contamination Superfund Site, Chehalis, Washington. Prepared for S.C. Breen Construction
Company. Issaquah, Washington. May 24, 2002.
2003. Remedial Investigation/Feasibility Study Work Plan, Hamilton/Labree Roads
Groundwater Contamination Superfund Site, Chehalis, Washington. Prepared for S.C. Breen
Construction Company. Issaquah, Washington. July 2003.
GeoEngineers. 2001. Interim Remedial Action Report, S.C. Breen Construction Company
Property, Chehalis, Washington. Prepared for S.C. Breen Construction Company. March 2001.
Geo-Recon International (Geo-Recon). 1996. Geophysical Investigation of the Hamilton-LaBree
Properties, Chehalis, Washington. Prepared for Washington State Department of Ecology.
Olympia, Washington. October 1996.
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Interstate Technology and Regulatory Council (ITRC). 2010. Use and Measurement of Mass
Flux and Mass Discharge. August 2010.
Lockheed Martin Technology Services (Lockheed Martin). 2008. Memorandum: Hamilton
Labree Vapor Intrusion Site, Chehalis, WA, Work Assignment #EAC00285 - Trip Report.
Prepared for EPA Emergency Response Team. March 21, 2008.
McDade, J.M., Travis M. McGuire,Charles J. Newell. 2005. Analysis of DNAPL Source-
Depletion Costs at 36 Field Sites. REMEDIATION. Spring 2005: p. 9-13.
McGuire, T.M., James M. McDade, and Charles J. Newell. 2006. Performance of DNAPL
Source Depletion Technologies at 59 Chlorinated Solvent-Impacted Sites. Ground Water
Monitoring & Remediation. 26(1): p. 73-84.
Parametrix. 2006. Hamilton/Labree Roads Groundwater Contamination Superfund Site
Feasibility Study. Prepared for EPA Region 10 under AES Contract No. 68-S7-03-04. April
2006.
2009. Technical Memorandum: Final Hamilton/Labree Roads Superfund Site: Site Data
Usability Review. Prepared by Parametrix for EPA Region 10 under AES Contract No. 68-S7-
03-04. May 13, 2009.
SAIC. 1997. Phase I and II Data Presentation Report for Hamilton/Labree Roads
Perchloroethylene (PCE) in Groundwater Site. Prepared by Science Applications International
Corporation for Washington Department of Ecology under Ecology Contract C9300048,
SAI019. Olympia, Washington. June 1997.
United States Environmental Protection Agency (EPA). 1988. Guidance for Conducting
Remedial Investigations and Feasibility Studies Under CERCLA. Interim Final. Publication
EPA/540/G-89/004. OSWER Directive 9355.3-01. October 1988.
1991. A Guide to Principal Threat and Low Level Threat Wastes. Office of Solid Waste
and Emergency Response. Superfund Publication 9380.3-06FS. November 1991.
2000. A Guide to Developing and Documenting Cost Estimates during the Feasibility
Study. EPA 540-R-00-002. July.
2001a. Action Memorandum for Removal Actions with Cost Ceiling less than $200,000,
Findings of Imminent and Substantial Endangerment, Hamilton Labree Roads. June 26, 2001.
2001b. Administrative Order of Consent for Remedial Investigation/Feasibility Study,
S.C. Breen Construction Company. U.S. EPA Docket No. CERCLA 10-2002-0002. October 31,
2001.
. 2002a. Action Memorandum for Removal Actions with Cost Ceiling less than $200,000,
Findings of Imminent and Substantial Endangerment, Hamilton Labree Roads. January 30, 2002.
13-2
-------
&EPA
Hamilton/LaBree Proposed Plan
2002b. Action Memorandum for a Removal Action and Request for the $2 Million
Exemption Ceiling at the Hamilton-LaBree Groundwater Contamination Site, near Chehalis,
Lewis County, Washington. Site ID 08R. July 5, 2002.
2002c. Amendment to the Action Memorandum for the Hamilton LaBree Removal Action
to increase the project ceiling costs. September 25, 2002.
2002d. OSWER Draft Guidance for Evaluating the Vapor Intrusion to Indoor Air Pathway
from Groundwater and Soils (Subsurface Vapor Intrusion Guidance). EPA 530-D-02-004.
November.
2004. Request for Approval of a Time Critical Removal Action and a 12-Month
Exemption at the Hamilton/LaBree Groundwater Site in Chehalis, WA. December 16, 2004.
2008. Memorandum: Hamilton Labree Vapor Intrusion Study. Prepared by EPA
Environmental Response Team. March 20, 2008.
URS 2004. Draft (Revision 1) Engineering Evaluation/Cost Analysis Report, Hamilton Road
Impact Area, Hamilton-Labree Roads Superfund Site, Chehalis, Washington. Prepared for
USEPA Region 10 under RAC Contract 68-W-98-228. August 2004.
Washington State Department of Ecology (Ecology). 1999. Source Investigation Report for
Hamilton/Labree Roads Chlorinated Solvent Site. Olympia, Washington. January 1999.
2005. Hydrology and Quality of Groundwater in the Centralia-Chehalis Area Surficial
Aquifer. Washington State Groundwater Assessment Program. Publication No. 05-03-040.
December 2005.
2006. Water Quality Standards for Surface Waters of the State of Washington.
Washington Administrative Code (WAC) 173-201 A. November 20, 2006.
2008. 2004 List of Category 5 Waters.
www.ecy.wa.gov/programs/wq/303d/2002/2004_documents/list_by_category-cat5.html.
Washington State Department of Health (DOH). 1999. Health Consultation, Evaluation of
Contaminants: Residential Domestic Well near the Hamilton/Labree Road PCE Site, Hamilton
Road PCE, Chehalis, Lewis County, Washington. August 16, 1999.
Weigle, J.M. and B.L. Foxworthy. 1962. Geology and Groundwater Resources of Western
Central Lewis County, Washington. Water Supply Bulletin No. 17. State of Washington
Department of Conservation, Division of Water Resources.
Western Regional Climate Center. 2006. www.wrcc.dri.edu.
13-3
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^ EPA
Environmental Protection Written Comments
Agency
The U.S. Environmental Protection Agency (EPA) invites your comments on its Proposed Plan for
cleaning up contamination in the Hamilton Road Impacted Area (HRIA). Your comments are
encouraged to help shape the final cleanup plan. EPA will consider all comments received during the
public comment period from September 28, 2012 through November 9, 2012.
ADDRESS Are you interested in
and/or future mailings?
NAME E-mail AFFILIATION Check Here
YOUR COMMENTS
If you would like more time to consider your comments, please take this with you. To mail this form,
please fold it twice (see the markings on the back), staple or tape it shut. Add a postage stamp and mail
it no later than November 9, 2012. Or, e-mail your comments to langton.tamara@epa.gov
-------
Please send comments, postmarked by November 9, 2012. Fold paper along dotted lines, tape it closed,
and add postage stamp.
Place
Stamp
Here
Ms. Tamara Langton
US EPA Region 10
1200 Sixth Ave, Suite 900
Office of Environmental Cleanup, ECL-113
Seattle, WA98101
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TABLES
-------
Table 3-1 Contaminant Mass, Volume, and Surface Area
Concentration Area
Mass
Groundwater
in ()*
Mass (Kg)
Soil*
Total (Mass
Kfl)*
Total Plume
Volume
(cubic yards)
Surface Area
(square feet)
Berwick Creek
Sediment, >0.468 mg/kg
Kg
163
163
1360
7348
Subsurface Soil >1
mg/kg
221
245
421
21981
38,805
Subsurface Soil >10
mg/kg
92
171
250
3599
8,741
Subsurface Soil >38
mg/kg
35
102
137
1035
3769
>20,000 |jg/L
238
268
506
42,235
33,342
>10,000 |jg/L
275
291
566
62,876
45,575
>4,000 |jg/L
289
308
597
87,840
64,162
>3,000 |jg/L
307
311
618
105,000
83,619
>2,000 |jg/L
315
318
633
136,000
91,942
>1,500 |jg/L
320
320
640
150,000
100,695
>1,000 |jg/L
325
325
650
177,000
120,253
>500 |jg/L
337
329
661
336,000
209,119
>100 |jg/L
343
336
679
485,000
305,979
>5 |jg/L (MCL)
349
337
686
639,000
339,260
Notes:
Average Bulk Soil Density = 1.7 gm/cc
Total Porosity = 0.36
kg - kilograms
[jg/kg - micrograms per kilogram
|jg/L - micrograms per liter
> - greater than
Page 1 of 1
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Table 6-1 Chemical-Specific ARARs/TBCs
Standard, Requirement,
Criterion, Or Limitation
Citation Or
Reference
Description
Status
Comments
FEDERAL
Soil:
EPA Soil Screening Guidance
EPA/540/R-96/018
Provides methodology for calculating risk-
based, site-specific soil screening levels.
TBC
Used to standardize and accelerate site
cleanup.
Groundwater:
Maximum Contaminant Limits
(MCLs); Safe Drinking Water Act,
National Primary Drinking Water
Regulations
40 CFR 141.11-. 16
MCLs regulate concentration of
contaminants in public drinking water
supplies but may also be considered for
groundwater aquifers used for drinking
water.
Relevant and
Appropriate
Relevant to VOCs, SVOCs and metals
in groundwater.
Maximum Contaminant Limit
Goals (MCLGs); Safe Drinking
Water Act, National Primary
Drinking Water Regulations
40 CFR 141.50-54
MCLGs are health-based criteria that
should be evaluated for groundwater
contamination.
Relevant and
Appropriate
Relevant to contaminants in
groundwater.
Guidance on Remedial Actions for
Contaminated Groundwater at
Superfund Sites
EPA/540/G-88/003
Provides information on remedial
technologies to address groundwater
contamination.
TBC
Relevant to contaminants in
groundwater.
Guidelines for Ground-Water
Classification Under the EPA
Groundwater Protection Strategy
813R86001
(nepis.epa.gov)
Presents guidelines for classifying
groundwater in one of three classification
categories based on ecological importance,
replaceability, and vulnerability
considerations
TBC
Useful in identifying ARARs and
establishing cleanup goals for site
groundwater based on policy that
different groundwaters merit different
levels of protection.
Surface Water:
Clean Water Act Section 304—
Federal Ambient Water Quality
(National Recommended Water
Quality Criteria, November 2002)
EPA-822-R-02-047
Provides chemical concentrations for
acceptable ambient water quality.
Relevant and
Appropriate
Potentially relevant and appropriate to
ambient surface water quality in and
point-source discharges to the surface
water in Berwick Creek should remedial
activities cause a release to surface
water. The PCE value for human
exposure to both water and organisms
is 0.69 |jg/L and to organisms only is
3.3 |jg/L.
Page 1 of 6
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Standard, Requirement,
Criterion, Or Limitation
Citation Or
Reference
Description
Status
Comments
FEDERAL (Continued)
Clean Water Act's National Toxics
Rule
40 CFR 131.36
Provides values that have to be met for
point-source discharges to surface water.
Applicable
Potentially applicable to point-source
discharges to Berwick Creek and on-
site stormwater ditches should remedial
activities cause release to surface
water. If applicable, these values would
have to be met at the mixing zone
boundary established for the discharge.
The PCE value for human exposure to
both water and organisms is 0.8 |jg/L
and to organisms only is 8.85 |jg/L.
Hazardous Waste:
RCRA
Part 261 - Identification and
Listing of Hazardous Waste
40 CFR Part 261-265,
270, and 271
Defines those solid wastes which are
subject to regulations as hazardous wastes,
and lists specific chemical and industry-
source wastes.
Applicable
Applicable to determining whether
wastes are considered hazardous under
RCRA.
RCRA TCLP and Land Ban
Requirements for Landfilling
40 CFR 261
Requirements and restrictions on
hazardous waste disposal in landfills.
Applicable
Applicable to disposal of contaminated
material.
RCRA Land Disposal Restrictions
40 CFR 268
Establishes standards for land disposal of
RCRA hazardous waste. Requires
treatment to diminish a waste's toxicity
and/or minimize contaminant migration.
Applicable
Applicable if remedial activities
generate and include land disposal of
waste that is characterized as
hazardous.
Other:
EPA Region III Risk-based
Concentration Table
NA
Establishes chemical screening guidelines
for use during risk assessment.
TBC
May be useful in development of
cleanup goals.
Oak Ridge National Laboratory
Screening Criteria
http:/epa-
prgs.ornl.gov/chemicals
/index.shtml
Established regional chemical screening
levels to be used in risk assessments.
TBC
May be useful in development of
cleanup goals.
National Ambient Air Quality
Standards
40 CFR 50.6, 50.12
Provides acceptable ambient air quality
levels for particulate matter and lead
Applicable
Applicable to earth-moving activities as
well as to treatment processes that may
include mixing or other processes that
result in potential releases of
particulates or lead.
Page 2 of 6
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Standard, Requirement,
Criterion, Or Limitation
Citation Or
Reference
Description
Status
Comments
STATE - WASHINGTON
Soil:
Model Toxics Control Act
Regulations
WAC 173-340-740, -
745
Regulates the investigation and cleanup of
releases to the environment that may pose
a threat to human health or the
environment. Establishes cleanup levels for
soil.
Applicable
The Method A soil value for PCE is
0.05 mg/kg for both unrestricted and
industrial land use for human health
protection. The unrestricted land use
Method B value for PCE is 22 mg/kg for
protection from direct contact
(residential); 110 mg/kg
(commercial/industrial), and 924 mg/kg
(recreational).
Groundwater:
MTCA Regulations
WAC 173-340-720
Regulates the investigation and cleanup of
releases to the environment that may pose
a threat to human health or the
environment. Establishes cleanup levels for
groundwater.
Applicable
MTCA groundwater cleanup levels are
potentially applicable to HRIA
groundwater. The Method A
groundwater cleanup value for PCE is 5
|ig/L, and the Method B groundwater
cleanup value for PCE is 0.81 |ig/L.
Water Quality Standards
WAC 173-200-040
Provides criteria establishing maximum
contaminant concentrations for the
protection of a variety of beneficial uses of
Washington's groundwater.
TBC
Not applicable to cleanups approved
under MTCA 70.105D or by EPA under
CERCLA. Cleanup standards for such
sites shall be developed under WAC
173-340-720.
Sediment:
Sediment Cleanup Standards
WAC 173-204-570
Provide standards to eliminate adverse
effects on biological resources and
significant health threats to humans from
sediment contamination
Applicable
Sediment clean up objectives are the
freshwater sediment standards provided
in 173-204-340. The Department
determines on a case by case basis the
criteria, methods and procedures
necessary to meet the intent of the
chapter.
Surface Water:
MTCA Regulations
WAC 173-340-730
Regulates the investigation and cleanup of
releases to the environment that may pose
a threat to human health or the
environment. Establishes cleanup levels for
surface water.
Applicable
Applicable if remedial activities cause a
release to surface water. MTCA surface
water cleanup levels are potentially
applicable to Berwick Creek and the
small and unnamed ditches. The
Method B value for PCE is 0.39 |ig/L.
Air:
MTCA
Regulations
WAC 173-340-750
Regulates the investigation and cleanup of
releases to the environment that may pose
a threat to human health or the
environment. Establishes cleanup levels for
air.
Applicable
Applicable if remedial activities cause a
release to air.
Page 3 of 6
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Standard, Requirement,
Criterion, Or Limitation
Citation Or
Reference
Description
Status
Comments
STATE - WASHINGTON (Continued)
Hazardous Waste:
Washington Hazardous Waste
Management Act Regulations
WAC 173-303
Requirements and restrictions on
hazardous waste disposal.
Applicable
This regulation is potentially applicable
to alternatives that would involve
disposal of contaminated media in an
off-site location. The area of
contamination policy allows
contaminated media to be consolidated
within the same area of a site without
triggering RCRA or Washington
dangerous waste regulations.
Several waste streams from the site
could be hazardous wastes, because
they could contain PCE at
concentrations high enough to fail the
TCLP; the PCE TCLP threshold is
0.7 mg/L.
Other:
Model Toxics Control Act
Regulations: Cleanup Standards:
(General)
173-340 -700
Provides an overview of the methods for
establishing cleanup standards that apply to
a release or threatened release of a
hazardous substance at a site.
Applicable
Applicable to establishment of PRGs
Page 4 of 6
-------
Standard, Requirement,
Criterion, Or Limitation
Citation Or
Reference
Description
Status
Comments
STATE - WASHINGTON (Continued)
Model Toxics Control Act
Regulations: Cleanup Standards
173-340-703
173-340-704 Use of
Method A
173-340-705 Use of
Method B
173-340-706 Use of
Method C
Describes elimination of certain hazardous
substances that contribute a small
percentage of the overall threat to human
health and the environment at a site, and
use of the remaining hazardous
substance(s) as an indicator for purposes of
defining site cleanup requirements.
Provides a method to establish cleanup
levels for sites that have few hazardous
substances,
Provides a method to establish cleanup
levels for sites unless one or more of
the conditions for using Method A or
Method C are demonstrated to exist
and the person conducting the cleanup
action elects to use that method.
Method C cleanup levels represent
concentrations that are protective of human
health and the environment for specified
site uses and conditions. A site (or portion
of a site) that qualifies for a Method C
cleanup level for one medium does not
necessarily qualify for a Method C cleanup
level in other media. Each medium must be
evaluated separately using the criteria
applicable to that medium.
Applicable
Applicable to establishment of PRGs
Page 5 of 6
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Acronyms:
ARAR: Applicable or Relevant and Appropriate Requirement
CERCLA: Comprehensive Environmental Response, Compensation, and Liability Act
CFR: Code of Federal Regulations
EPA: U. S. Environmental Protection Agency
HRIA: Hamilton Road Impacted Area
mg/kg: milligram per kilogram
|jg/L: microgram per liter
mg/L: milligram per liter
MTCA: Model Toxics Control Act
PCE: Tetrachloroethene
RCRA: Resource Conservation and Recovery Act
SVOC: Semivolatile Organic Compound
TBC: To Be Considered
TCLP: Toxicity Characteristic Leaching Procedure
VOC: Volatile Organic Compound
WAC: Washington Administrative Code
Page 6 of 6
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Table 6-2 Location-Specific ARARs/TBCs
Standard, Requirement,
Criterion, Or Limitation
Citation Or Reference
Description
Status
Comments
FEDERAL
Federal Protection of Wetlands
and Management of Floodplains
Executive Order Nos.
11990 and 11988
Establishes requirements for the
preservation of wetlands and floodplain
areas.
Applicable
May be applicable to remedial actions
that affect wetland and floodplain
areas if any affected properties are
located within wetlands or floodplain
areas.
National Historic Preservation Act
Archeological Resources
Protection Act
16 USC 470; et. Seq.; 40
CFR 6.301 (b); 36 CFR
Part 800
16 USC 469; 40 CFR
6.301 (c)
Minimizes impact of actions on historic
properties and landmarks.
Provides protection from actions that
may cause irreparable harm, loss, or
destruction of artifacts
Applicable
Applicable to actions at historic
properties or landmarks, or properties
at the site that contain historical and
archeological data.
Native American Graves
Protection and Repatriation Act
43 CFR Part 10
Protects Native American burials from
desecration through the removal and
trafficking of human remains and
"cultural items," including funerary and
sacred objects.
Applicable
Potentially applicable to remedial
actions at the site because it is
possible that the disturbance of Native
American materials could occur as a
result of work in the stream bed or
subsurface excavations elsewhere at
the site. Such materials are not known
to be present at the site, but could be
inadvertently uncovered during soil or
sediment removal.
Endangered Species Act of 1973
16 USC 1531-1543; 50
CFR Parts 17, 401; 40
CFR 6.302 (h)
Provides protection of critical habitat
upon which endangered or threatened
species depend.
Applicable
Applicable to actions that impact
critical habitat of endangered or
threatened species. USFWS has
determined that federal threatened
species (bald eagle and bull trout) may
use the project area.
Page 1 of 2
-------
Standard, Requirement,
Criterion, Or Limitation
Citation Or
Reference
Description
Status
Comments
FEDERAL (Continued)
Magnuson-Stevens Fishery
Conservation and Management Act
Regulations
50 CFR Part 600
Consideration of the effects of federal actions on
EFH for certain species is required. Federal
agencies whose actions might adversely affect an
EFH-managed species must formally consult with
NOAA Fisheries regarding the action. If NOAA)
fisheries were to determine that an action would
adversely affect EFH, the agency would provide
EFH conservation recommendations.
Applicable
Potentially applicable to actions
within Berwick Creek, which has
been designated EFH for both
coho and Chinook salmon.
Clean Water Act, Section 401,
Water Quality Certification
33 USC 1340
Requires a certification of water quality to be
issued by the responsible government authority to
state that remedial actions will not violate
applicable water quality standards.
Applicable
Substantive requirements
potentially applicable to in-water
remedial actions at Berwick
Creek.
Clean Water Act (Dredge and Fill
Requirements)
33 USC 1251-1376; 40
CFR 230, 231
Provides protection to waters in and around the
site.
Relevant and
Appropriate
Relevant and appropriate to
actions involving capping, berm
construction and/or onsite
disposal of contaminated soil that
may impact local water bodies.
STATE - WASHINGTON
Washington Hydraulics Project
Approval
WAC 220-110
WAC 220-110-040
through -224
Requires WDFW approval for projects that will
use, divert, obstruct, or change the natural flow or
bed of waters of the state.
Substantive technical provisions include
considerations for: bank protection, channel
change/realignment, temporary bypass culvert,
flume, or channel, dredging in freshwater areas,
gravel removal, outfall structures, water diversions
Applicable
Applicable to remedial actions
taken at Berwick Creek. Will
require adherence to instream
work windows, which are typically
issued under the authority of this
program.
Acronyms
ARAR: Applicable or Relevant and Appropriate Requirement
CFR: Code of Federal Regulations
EFH: essential fish habitat
NOAA: National Oceanic and Atmospheric Administration
TBC: To Be Considered
USC: United States Code
WAC: Washington Administrative Code
WDFW: Washington Department of Fish and Wildlife
Page 2 of 2
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Table 6-3 Action-Specific ARARs/TBCs
Standard, Requirement,
Criterion, Or Limitation
Citation Or
Reference
Description
Status
Comments
FEDERAL
Hazardous Waste:
RCRA Subtitle C Hazardous Waste
Treatment Facility Design and
Operating Standards for Treatment
and Disposal Systems, (i.e., landfill,
incinerators, tanks, Containers, etc.)
(Minimum Technology
Requirements)
40 CFR 264 and 265
Develops standards for hazardous waste
treatment and disposal activities.
Applicable
Applicable if remedial activities
include the management of
hazardous wastes at treatment and
disposal facilities.
RCRA Manifesting, Transport and
Recordkeeping Requirements
40 CFR 262
Develops guidelines for record-keeping of
the management actions for hazardous
wastes.
Applicable
Applicable if remedial activities
include the off-site transport of
hazardous waste.
RCRA Storage Requirements
40 CFR 264; 40 CFR
265, Subparts I and J
Develops standards for the storage of
hazardous wastes.
Applicable
Applicable if remedial activities
include the storage of hazardous
waste greater than 90 days.
RCRA Subtitle D Nonhazardous
Waste Management Standards
40 CFR 257
Develops standards for the management of
non-hazardous wastes.
Applicable
Applicable if remedial activities
include the management of non-
hazardous wastes.
Off-Site Transport of Hazardous
Waste
EPA OSWER Directive
9834.11
Establishes technical guidelines for the off-
site transport of hazardous wastes.
TBC
TBC if remedial activities include the
off-site transport and management
of hazardous waste.
DOT Rules for Hazardous Materials
Transport
49 CFR 107,171.1-
171.500
Establishes specific DOT rules and
technical guidelines for the off-site transport
of hazardous materials.
Applicable
Applicable if remedial activities
include the off-site transport and
management of hazardous waste.
RCRA - Part 262 Standards for
Generators. Part 263 Standards for
Transporters
40 CFR Parts 262 and
263
Applicable to generators and transporters of
hazardous waste.
Applicable
Applicable to off-site disposal or
treatment of hazardous waste.
RCRA - Part 264, Subtitle C
40 CFR Part 264
Applicable to the treatment, storage,
transportation and disposal of hazardous
waste defined in 40 CFR Part 261.
Applicable
Applicable to off-site disposal or
treatment of hazardous waste.
RCRA - Part 268 Land Disposal
Restrictions
40 CFR Part 268
Establishes standards for land disposal of
RCRA hazardous waste. Requires
treatment to diminish a waste's toxicity
and/or minimize contaminant migration.
Applicable
Applicable if remedial activities
include land disposal of RCRA
hazardous waste.
Page 1 of 7
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Standard, Requirement,
Criterion, Or Limitation
Citation Or
Reference
Description
Status
Comments
FEDERAL (Continued)
Transportation of Hazardous
Wastes
49 CFR 170-189
Federal Highway Administration,
Department of Transportation National
Highway Traffic Safety Administration
regulations are codified in 23 CFR Parts
1-1399.
Applicable
Applicable to remedial activities that
involve the off-site transportation of
hazardous waste.
Groundwater:
EPA Underground Injection Control
Regulations
40 CFR 144 and 146
Regulates injections of underground
sources of drinking water by specific classes
of injection wells.
Relevant and
Appropriate
Relevant to use of any remediation
technologies that involve injections
into drinking water aquifer.
Surface Water:
Clean Water Act's National Pollutant
Discharge Elimination System
(NPDES) Regulations
40 CFR Part 122-125
The NPDES program requires that permits
be obtained for point-source discharges of
pollutants to surface water. Under this
regulation, a point-source discharge to a
surface water body cannot cause an
exceedance of water quality standards in
the receiving water body outside the mixing
zone.
Applicable
Although permits would not be
required for on-site actions under
CERCLA, the substantive regulatory
requirements of the NPDES permit
program are potentially applicable to
the direct discharge of treated
groundwater to a surface water
body such as Berwick Creek as well
as the unnamed or small ditches
connected to Berwick Creek.
Clean Water Act's National Toxics
Rule (NTR)
40 CFR 131.36
Provides values that have to be met for
point-source discharges to surface water.
Applicable
Potentially applicable to point-
source discharges to Berwick Creek
and on-site stormwater ditches. If
applicable, these values would have
to be met at the mixing zone
boundary established for the
discharge. The PCE value for
human exposure to both water and
organisms is 0.8 |jg/L and to
organisms only is 8.85 |jg/L.
Clean Water Act Section 304 -
Federal Ambient Water Quality
National Recommended
Water Quality Criteria,
November 2002, and 67
Federal Register 79091-
79095, December 27,
2002
Provides chemical concentrations for
acceptable ambient water quality.
Relevant and
Appropriate
Potentially relevant and appropriate
to point-source discharges to
Berwick Creek. The PCE value for
human exposure to both water and
organisms is 0.69 |jg/L and to
organisms only is 3.3 |jg/L
Page 2 of 7
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Standard, Requirement,
Criterion, Or Limitation
Citation Or
Reference
Description
Status
Comments
FEDERAL (Continued)
Other:
Surface Mining Control Act of 1977
25 USC. 1201 et. seq.;
30 CFR Parts 816.11,
.95, .97, .100, .102, .111,
113, .114, .116
Provides requirements for removing
contaminated soils
Relevant and
Appropriate
Includes requirements for postings
(.11), stabilization (erosion
control)(.95), minimizing
disturbances(.97), reclamation
(.100), sloping (.102) and
revegetation (.100, . 102, .111, .113,
.114)
Clean Air Act
42 USC 7401, Section 1
12
Established limits on pollutant emissions to
atmosphere from specific industrial and
commercial activities. Establishes standards
to protect public health and welfare and
ambient air quality.
Relevant and
Appropriate
Some treatment alternatives may
impact ambient air quality.
National Ambient Air Quality
Standards
40 CFR 50.6
Requires that the remedial action include
fugitive dust control measures
Applicable
Applicable to earth-moving activities
as well as to treatment processes
that may include mixing or other
processes that result in potential
releases of particulates
National Emission Standards for
Hazardous Air Pollutants
40 CFR Part 261
Establishes specific emissions levels
allowed for toxic air pollutants
Applicable
Applicable to treatment alternatives
that may emit toxic pollutants to the
air.
Clean Water Act's Pretreatment
Regulations
40 CFR Part 503.5
Limits pollutants in wastewater discharges
to sanitary sewer systems to protect
POTWs from accepting wastewater that
would damage their system or cause them
to exceed their NPDES permit discharge
limits
Applicable
Potentially applicable to the
discharge of treated groundwater to
City of Chehalis POTW. The City of
Chehalis pretreatment ordinance
would be potentially applicable as
well.
Stormwater Permit Program
40 CFR 122.26
Best management practices must be used
and appropriate monitoring performed to
ensure that stormwater runoff does not
cause an exceedance of water quality
standards in a receiving surface water body.
Applicable
Substantive requirements of the
general stormwater permit program
for stormwater discharges
associated with construction
activities disturbing over 1 acre are
potentially applicable to remedial
actions at HRIA.
Page 3 of 7
-------
Standard, Requirement,
Criterion, Or Limitation
Citation Or
Reference
Description
Status
Comments
STATE-WASHINGTON
Solid Waste:
Washington Solid Waste Handling
Standards
WAC 173-350
Provides waste management requirements
for non-hazardous wastes.
Applicable or
Relevant and
Appropriate
Potentially applicable to off-site
disposal of solid nonhazardous
wastes and are potentially relevant
and appropriate to on-site remedial
actions governing contaminated
media management. Requirements
for contaminated media disposal will
be found in the permit of the landfill
that agrees to accept the waste.
Hazardous Waste:
Hazardous Waste Management Act
Regulations
WAC 173-303
Regulates disposal of contaminated media
in an off-site location. Generators of solid
waste must determine whether that waste is
hazardous (dangerous) waste. If the wastes
destined for off-site disposal are determined
to be hazardous, then EPA will accumulate,
manifest, and transport them as required by
WAC 173-303-170, 180, 190, and 200 to an
off-site facility that is acceptable under the
Off-Site Disposal Rule (40 CFR 300.440).
(The area of contamination policy allows
contaminated media to be consolidated
within the same area of a site without
triggering RCRA or Washington dangerous
waste regulations.)
Applicable
Applicable if any hazardous
materials are taken offsite. Several
waste streams from the site could
be hazardous wastes if they contain
PCE at concentrations high enough
to fail the TCLP. PCE TCLP
threshold is 0.7 mg/L. Materials that
are potential hazardous wastes
include stream sediments, drill
cuttings, groundwater (purge water,
etc.), and spent activated carbon
units from the treatment system.
Surface Water:
Washington State Water Quality
Standards for Surface Waters
WAC 173-201A
Provides limitations on parameters such as
turbidity, temperature, dissolved oxygen,
and pH for protection of organisms.
Protects freshwater aquatic life by
specifying protection criteria by stretch of
surface waters. Tributaries of waters whose
uses are designated salmon and trout
spawning, core rearing and migration, or
extraordinary primary contact recreation are
protected at the same level as the waters
themselves.
Applicable
Limitations would not serve as
cleanup standards but would be
potentially applicable to remedial
actions.
Page 4 of 7
-------
Standard, Requirement,
Criterion, Or Limitation
Citation Or
Reference
Description
Status
Comments
STATE - WASHINGTON (Continued)
Washington Surface Water Quality
Standards—Short-Term
Modifications
WAC 173-201A-410
Provides for short-term modifications of
standards for specific water bodies on a
short-term basis when necessary to
accommodate essential activities, respond
to emergencies, or to otherwise protect the
public interest.
Applicable
The substantive requirements of this
regulation are potentially applicable
for remedial action in-water work at
Berwick Creek.
Other:
Washington Water Well
Construction Act Regulations
WAC 173-160
Provides requirements for water well
construction.
Applicable
Potentially applicable to the
installation, operation, or closure of
monitoring and treatment wells at
HRIA.
Washington Hydraulics Project
Approval
WAC 220-110
Requires WDFW approval for projects that
will use, divert, obstruct, or change the
natural flow or bed of waters of the state.
WDFW typically issues in stream work
windows under the authority of this program.
Applicable
Substantive technical provisions
written for freshwater hydraulic
projects covered in WAC 220-110-
040 through -224 are potentially
applicable to work within or effecting
Berwick Creek
Washington Clean Air Act and
Implementing Regulations
SWCAA Regulation
WAC 173-400
WAC 173-460
SWCAA 400
Air emissions at the site boundary must fall
below the acceptable source impact limit of
1.1 |jg/m3 PCE (WAC 173-460-150).
Compliance could be demonstrated through
modeling of PCE sources from treatment
technologies with air emissions. WAC 173-
400 also requires control of fugitive dust
emissions during construction.
Applicable
Applicable to earth-moving activities
as well as to treatment processes
that may include mixing or other
processes that result in potential
releases of emissions to air.
Model Toxics Control Act
Regulations: Selection of Cleanup
Action
WAC 173-340-360
Model Toxics Control Act Regulations:
Describes the minimum requirements and
procedures for selecting cleanup actions.
Because cleanup actions will often involve
the use of several cleanup action
components at a single site, the overall
cleanup action shall meet the requirements
of this section.
Applicable
Applicable to various components of
the remediation alternatives.
Page 5 of 7
-------
Standard, Requirement,
Criterion, Or Limitation
Citation Or
Reference
Description
Status
Comments
STATE - WASHINGTON (Continued)
Model Toxics Control Act:
Regulations Compliance
Monitoring Requirements
WAC 173-340-410
Describes minimum compliance monitoring
requirements. Three types of compliance
monitoring: protection (confirm that human
health and the environment are adequately
protected during construction and the
operation and maintenance period of an
interim action as described in the safety and
health plan); performance (confirm that the
interim action has attained cleanup
standards and, if appropriate, remediation
levels or other performance standards such
as construction quality control
measurements or monitoring necessary to
demonstrate compliance with a permit or,
where a permit exemption applies, the
substantive requirements of other laws);
and, conformational monitoring (confirm that
human health and the environment are
adequately protected during construction
and the operation and maintenance period
of an interim action or cleanup action as
described in the safety and health plan). In
all cases, compliance monitoring plans are
required.
Applicable
Applicable to monitoring
components of the remediation
alternatives.
Model Toxics Control Act
Regulations: Interim Actions
WAC 173-340-430
An interim action is distinguished from a
cleanup action in that an interim action only
partially addresses the cleanup of a site.
This regulation describes the general
requirements for interim actions, timing and
relationship to the larger cleanup action
Applicable
SEPA
WAC 192-11
Requires a review of potential damage that
occurs to the environment as a result of
man's activities.
Applicable
SEPA checklist may be required
prior to construction of a
remediation system at the site.
Page 6 of 7
-------
Standard, Requirement,
Criterion, Or Limitation
Citation Or
Reference
Description
Status
Comments
STATE - WASHINGTON (Continued)
Storm Water Management
WAC 173-220
Best management practices must be used
and appropriate monitoring performed to
ensure that stormwater runoff does not
cause an exceedance of water quality
standards in a receiving surface water body.
Applicable
Substantive requirements applicable
to construction, grading and
excavation activities conducted as
part of site remediation.
Acronyms:
ARAR: Applicable or Relevant and Appropriate Requirement
CFR: Code of Federal Regulations
EPA: U. S. Environmental Protection Agency
HRIA: Hamilton Road Impacted Area
mg/kg: milligram per kilogram
|jg/m : microgram per cubic meter
PCE: Tetrachloroethene
RCRA: Resource Conservation and Recovery Act
SEPA: State Environmental Policy Act
SWCAA: Southwest Clean Air Agency
TBC: To Be Considered
TCLP: Toxicity Characteristic Leaching Procedure
VOC: Volatile Organic Compound
WAC: Washington Administrative Code
WDFW: Washington Department of Fish and Wildlife
Page 7 of 7
-------
Table 6-4. Mass and Volume of PCE in HRIA Remediation Target Zones
Remediation Zone
Boundary
(PCE Concentration)
Mass
(kg)
Mass %
Volume
(1,000 cy)
Surface
Area
(acre)
Creek Bed
Sediment/surface soil
(>0.468 mg/kg)
163
NA1
1.36
0.17
Subsurface Soil (>10
mg/kg)
186
27%2
3.60
0.22
High Concentration
Groundwater (>4,000 pg/L)
411
60%3
87.8
1.6
1 Due to uncertainties in the sediment creek contaminant mass, the estimates were not included in the total mass
calculations using MVS for subsurface soil and groundwater.
2 Percent of the total MVS-estimated subsurface soil contaminant mass within HRIA.
3 Numbers represent estimated mass less the soil mass estimated for the Subsurface Soil Remediation Target Zone.
-------
Table 8-1 Criteria Priorities
Group
Criteria
Definition
Threshold Criteria
Overall Protection of Human Health
and the Environment
Compliance with ARARs
Standards that an
alternative must meet to be
eligible for selection as a
cleanup action unless an
ARAR waiver is used
Balancing Criteria
Long-Term Effectiveness and
Permanence
Reduction of Toxicity, Mobility, or
Volume through Treatment
Short-Term Effectiveness
Implementability
Cost
Technical criteria that weigh
the tradeoffs between
alternatives.
Modifying Criteria
State Acceptance and Community
Acceptance
Fully evaluated after
comments are received on
the Proposed Plan.
-------
Table 8-2. Summary of Comparative Analysis of Comprehensive Technology Scenarios
CTS
Components
Threshold Criteria
Overall
Protection of
Human Health
and the
Environment
Compliance
with ARARs
Long-Term
Effectivene
ss and
Permanenc
e
Reduction
of
Toxicity,
Mobility,
or Volume
through
Treatment
Short-
Term
Effectivene
ss
Impleme
Engineering/
Technical
Consideration
s
ntability
Estimated
Time for
Implementatio
n(years)
Present
Value
Cost
(Dollars)
CTS-
1
No Action
No
No
©
O
©
©
<1
$0
CTS-
2
In-situ thermal
treatment of
creek
sediment,
surface soil
and
subsurface
soils; in-situ
enhanced
bioremediation
of groundwater
Yes
Soil -Yes
Groundwater-
Yes, with
waivers
©
©
9
o
3
$8.8M
-------
Threshold Criteria
Reduction
of
Toxicity,
Mobility,
or Volume
through
Treatment
Implementability
CTS
Components
Overall
Protection of
Human Health
and the
Environment
Compliance
with ARARs
Long-Term
Effectivene
ss and
Permanenc
e
Short-
Term
Effectivene
ss
Engineering/
Technical
Consideration
s
Estimated
Time for
Implementatio
n(years)
Present
Value
Cost
(Dollars)
CTS-
3
In-situ thermal
treatment of
creek
sediment,
surface soil
and
subsurface
soils; in-situ
chemical
oxidation of
groundwater
Yes
Soil -Yes
Groundwater-
Yes, with
waivers
©
©
©
©
3
$10.7M
Notes:
Threshold and Balancing Criteria
(Excluding Cost)
© None
O Low
© Low to Moderate
© Moderate
0 Moderate to High
© High
-------
FIGURES
-------
* Thurman
Berwick Creek
Area
Hamilton Road
Impacted Area (HRIA)
^Hamilton Road
'SOS ¦!".
Acronyms:
HRIA - Hamilton Road Impacted Area |
OU - operable unit
Washington
Seattle
^f| Tacoma
Chehalis
Project
Site
u
i
r
u
i
I
, #• i
i *
-
i
L._"
J V
i V
L7J
i
I \
* PM «
¦J 1 1
m\ PHI ._
Legend
] HRIAOU1 Boundary
Sources:
1, p arametrix (March, 2010)
2- Image from © 2011 Google1
Figure 1-1
Site Location Map
oEPA
REGION 10
Hamilton / Labree Roads
Superfund Site
-------
r
• - .«
. JLi I
' A 1' -..
l£5 &;
fa.
*^BUb **••
Legend
Acronyms:
HRIA- Hamilton Road Impacted Area
OU - operable unit
HRIAOU1 Boundary
Estimated PCE Concentration
Boundary (Dashed Where
Inferred- Contour Values
in ug/L)
Creek Flow Direction
Groundwater Flow Direction
OU1 - HRIA
OU2 -|n eludes the Breen Property,
the Thurman Berwick Creek
Area, and the area west and
northwest of Labree Road
Maurin Road
N
Feet
Sources:
1. p arametrix (March, 2010)
cology and Environment, Inc. 2002]
2^mage from © 2011 Google1"
Figure 1-2
Overview of Hamilton/Labree
Superfund Site
oEPA
REGION 10
Hamilton / Labree Roads
Superfund Site
-------
\ r | " \^t~ r~i= ' i; '•• I n * C^xl
c< : , " XiYtMSSi
:%>>W
'k
'%; \ Ofi"
* v X1
¦^""•TTtT^v " ^ *AM* i. \
lj t }\. r_ I A* y. ¦¦ '
-ii '>%,* *p/?$r
V% V^V- ',
Krz—f
l|Ov
%¦; '=> . '¦- „ I -Y; -1 .1 1
r^. ;-"-----^L -¦ =, ---*W_/"%
rH
j '% 'JOrftJvJ.Tf f \ "U\V ¦-
\ %
i'"v HI ,1 I ¦¦>*"-' »
W*. \ I I | tl|
JT- ¦'
X5k\*V ••- i^9m, ' istf
¦ ,m v :uite /?/
tj /%"!
\$p A *y*i ^ ¦
sXfl
rV !¦ \ \ K«..
' Acron
Hamilton Road
ed Area
•,Oy - operable
bAMiLTQfij " p "Jj"."
4>
""Sv. ':!
+ :%% \J'l ; 1
<>
:¦ ^
N-p
f, ),••,
ffOAti '.
-^w - ¦ -—
v.. \ v^. —-
'^O
!jt: iVj--, ~' ~~
1 C%A3
-y-\w-
-i;
Legend
L., !
! HRIAOU1 Boundary
1,250
I L
N
Feet
1,250
J J
Sources:
1. Parametrix (March, 2010)
2. 7.5' USGS Quadrangle - Centralia, Washington.
Dated 1985 and 7.5' USGS Quadrangle -
Napavine, Washington. Dated 1985
Figure 3-1
Regional Topography and Drainage
oEPA
REGION 10
Hamilton / Labree Roads
Superfund Site
-------
BK10 SG-2
SB-403w* C
15 BK9\
ES
SW-4
Unnamed
Ditch #1
¦sa-2T5 7 SG-211
||eM09 S(G)-207SG-225
9AJE& SG-209 |
^ fa 0 O OSG-224 1
SSG-20d«^n62 S°-223 4 AB"651
S SB^410 SG-208 SG.219
I/-R1 |~|GP-501
>-112 MW-e^^i"463 ( m SG-220
i; K^°-221
MW-604%GF-5% AB-650
AB4 ' ¦ELgMBj! 0 SG-222
SG-202 MW-60r|^K3
GFM11 MW-R5® QMS
GP-110 e ®MW^°° ®MW-10
SG-201 4?'4%%
W"R6 AB2 ¦ BS-458
\ AB1 H BS-457
SG-204 O GF
0 GP-505
508 GP-528
SG-205 (J g]Gp4
GPA4 a
Unnamed
Ditch #2
GP-504
P BS-454
/^\SB-400
GPA3
GP-130
J
* — »" • GP-126
^GP-128
North Hamilton Road
GP-125
t' vji~- i
MW-22
,18®
I--'.a\ \ i ' '"V, * V J' • I T
MW-23>t
L* >
RS-19
3
-19 A
RS-
[vy f v
MW-24 • !
RS-24
Acronyms:
AB "auger bori n9
B -so il coring
BK "bank sample
-geoprobe bori n9
MW - monitoring well
PW -prj vate well
RS - reconnaissance boring
CC - creek channel SG - soil gas
GA- geophysical survey areaSW -s urface water
tilswISl
SG-233
B1 GP^Elf^ • •
GP"116 4* bKS65"451 SGcf6AB5
MW-R3 OsG-232
B2B2®® ®B*K7AB11 SG-217 •
GP-519 BS-452
MW-33
GP-124
MW-5
GP-122
GP-129
GP-120
GP
-121
=31
MW-608
GP-518
E
GP-514
® i
MW-R4
AB-652
SB405
GP-119
a*. s
AB6
GP-524
a
GP-517
a
GP-117
MW-3
GP-529
E
B25
PW-3
525
GP-531
MW-607
GP-509
GP-522
GP-527
a
MW-R11
B24
®
GP-523
GP-526
h/IW-16
MW-41
w
MW-14
MW-15
®\
Smith Tractor
Building
GP-507 Gp_109
~
BS-456 g|
BS-455 g
GP-108 T5T
AB7# P
BS-459
BS-460
GP-107
yp BS-468 _ ^
°%
m S3
m US
m
Legend
AB1
AB-650
~
4>
„ ' 1
fry
B1
®
VI
BS-451
V
CC-1
~
GP1
EH
GP-1Q4
~
GP-520
~
MW-10
MW-R5
PW-3
RS-1S
•
SB-40Q
M
SG1-20
•
SG-225
•
SW-5
A
BK10
•
GA-1
Auger Boring (E&E 2000-2001)
Auger Boring (URS 2003)
Soil Boring
Stream Bed
Creek Channel
Geoprobe Boring
(E&E 2000-2001;
soil and water samples)
Geoprobe Boring
(E&E 2000-2001;
soil samples only)
Geoprobe Boring (URS 2003)
Monitoring Well
Monitoring Well/Recovery Well
Private Well
Reconnaissance Boring
Stream Bank
Soil Gas
Soil Gas
Surface Water
Bank Sample
Geophysical Survey Area
Sources:
1. p arametrix (March, 2010)
cology and Environment, Inc. 2002]
3^lmage from © 2011 Google™
Figure 3-2
Historical Sampling Locations
HRIA
EPA
REGION 10
Hamilton / Labree Roads
Superfund Site
-------
wmrnm
Breen Property
MW-26
MW-33
Hamifto
Northwestern
\ Hot Spot
RS-18
MW-22
MW-23
MW-608
SW-4
mm
MW-R3
Unnamed Ditch #1
MW-13
MW-24" f
SW-7
MW-R9
MW-R2
MW-14
\ Southeastern
/ Hot Spot
MW-R7
MW-R8
MW-602
PW-3
MW-601
MW-605
MW-R6
MW-607
Unnamed Ditch #2
Hamilton Road
Impacted Area (HRIA)
MW-606
PW-2
Acronyms:
CC - creek channel
HRIA - Hamilton Road Impacted Area
MW - monitoring well
OU - operable unit
PW -prj vate well
RS - reconnaissance boring
SW -c urface water
Legend
HRIA OU1 Boundary
O Hot Spot
a Creek Channel
® Monitoring Well
® Monitoring Well/Recovery Well
® Private Weil
• Reconnaissance Boring
a Surface Water
N
100 0 100
I I I I J
Feet
Sources:
1. p arametrix (March, 2010)
2- Image from © 2011 Google1
Figure 3-3
HRIA Hot Spots
Site Map
EPA
Hamilton / Labree Roads
REGION "10 SuperfundSite
-------
-------
Breen Property
North Hamilton Road
MW-603 j
AB34
GP-521 MW-R7
~r ^ MW-Rf
-------
Breen Property
-— Hamilton Road
Impacted Area (HRIAJ^
North Hamilton Road
Thurman
Berwick cfpek
Area
•
i^iviwiaV-
SP-501
KpH
IW-602
t IS) GPA4
0GP-51O
GP3 ||]
GPA3
PW-12
** - ¦ »
MW
11
RS
I
MW-16
MW-11
RS
MW-12
RS-33
GP-524
a
MW-3
MW-4
HI
GP-529
PW
GP
531
GP-509
MW-607
GP-527 MW
0 ®
R11
Acronyms:
"auger bori n9
B -Crt il oorina
GP-523
GP-526
0
GP "aeoorobe bori n9
geoprooe oori
HRIA- Hamilton Road Impacted Area
MW - monitoring well
OU - operable unit
PCE - tetrachloroethene
PW -prj vate well
RS - reconnaissance boring
Legend
] HRIAOU1 Boundary
Historical Groundwater
—200= Deep (> 25 feet depth) for
PCE Isoconcentration in ug/L
~
~
©
I
El
Auger Boring (E&E 2000-2001)
Auger Boring (URS 2003)
Soil Boring
Monitoring Well
Monitoring Well/Recovery Well
Private Well
Reconnaissance Boring
Geoprobe Boring
(E&E 2000-2001;
soil and water samples)
Geoprobe Boring (URS 2003)
Notes:
1. PCE concentrations for some wells were ignored
due to the sample being located in a transition
zo ne between the shallow and deep zones of
th e shallow aquifer, it is presumed that these
I ocations underestimate true maximum
co ncentrations in the deep zone, especially
do wngradient of the United Rentals Building.
2. Contours are based on maximum groundwater
co ncentrations and do not represent a single
ti me-specific sampling event.
3. Image from ©2011 Google
Figure 3-6
Hamilton I Labree Lower Zone
of Shallow Aquifer
PCE Isoconcentration Plot - Historical
EPA
REGION 10
Hamilton / Labree Roads
Superfund Site
-------
Ambient 6
Ambient 2
Legend
] HRIA0U1 Boundary
a Sub-Slab Sample
Indoor Air Sample
Ambient Air Sample
Sources:
1. u S. EPA Environmental Response Team
P_C-04-032]
^mage from © 2011 Google™
Figure 3-7
Ambient Air and
Soil Vapor Sample Locations
oEPA
REGION 10
Hamilton / Labree Roads
Superfund Site
Breen Property
Ambient 5
•x-
Unit 1
( A
Unit 0
Ambient 4
Hamilton Road
Impacted Area (HRIA)
Units
~
I Umt4
Thurman
Berwick Creek
Area
Unit 2a
W
Ambient 1
Ambient 7
Unite
Acronyms:
HRIA - Hamilton Road Impacted Area
OU - operable unit
U,S. EPA - United States Environmental
rotection Agency
Unit 3
Ambiefnt 3
Units
-------
Thurman/
Berwick Creek
Area
Breen
Property
Hamilton Road
Impacted Area
(OU1)
(OU2)
Berwick Creek
Washdown Pad
& Housing
Various
Historic Spills
Current
Industrial
Facility
Hamilton
Road
IWM.
0©
C)(A)(B)
^ x Surface
y Water
Sri
LI
Berwick
Creek Sediments
III
Groundwater Surface
\
Contaminated
Groundwater
Water
Table
Contaminated Soil
and Potential
DNAPL
Vadose
Zone
>-
25'
o
c.
o
N
o
5
o
Sand
->
<
Contaminated
Groundwater
Contaminated
Groundwater
Shallow
Aquifer
cn
zr
O
>
_Q
—h
CD
\
/
Clay
Aquitard
¦¦¦¦
Legend
A - Sediment - Ingestion/Direct Contact (Residential, Aquatic, Terrestrial)
B - Surface Water - Ingestion/Direct Contact (Residential, Aquatic, Terrestrial)
C - Outdoor Air - Inhalation (Residential, Terrestrial)
D - Groundwater - Ingestion (Occupational, Residential)
E - Indoor Air - Inhalation (Occupational, Residential)
Groundwater flows from right to left, and slightly into the figure (west-northwest).
The two groundwater plumes commingle down gradient of the sources.
North is into page
Not to scale
Acronyms:
OU - operable unit
Figure 3-8
Conceptual Model
©EPA
REGION 10
Hamilton / Labree Roads
Superfund Site
-------
Unnamed
Ditch #1
vVlvk MW-9
gmIK/V^53 mg/kg!
(858 mg/Wl- kSB^ip.
(678 mg/kgV ^lj®?0/mS'k3l
(160 mg/kg} //A
399 mg/kgl^'"685 m9/k9)
GP-502V
(3,220 mgJkg)"
(972 mg/kg)
(756 mg/kg)
(155 mg/kg)
(110 mg/kg)
(53.4 mg/kg)
GR^503 y
(15fmg(kg)'
Unnamed
Ditch #2
Smith Tractor
Building
Acronyms:
AB - auger boring
DNAPL - dense nonaqueous phase liquid
GP - geoprobe boring
kg - kilogram
mg - milligram
"O
x
E
0
E
~o
0
(O
0
O
£=
O
O
LU
o
Q_
TO
O
a
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o
03
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0
03
(/)
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a
o
o
c\j
CD
o
CD
LO
0
"O
0
a
0
en
&
LU
CO
Z>
00
o
00
o
LO
35 -
CD
>
(/)
£
MW - monitoring well
PCE - tetrachloroethene
SB - soil boring
o
CM
LO
CM
0
_q
E
0
Q.
0!
CO
-------
¦;v: c W^,y ^
¦ ^
r!
Legend
| HRIA0U1 Boundary
Creek Bed Sediment/ Bank
Surface Soil Remediation Zone
(PCE greater than 0.468 mg/kg)
(Area: 7,348 sq. ft.)
Subsurface Soil
Remediation Zone
(PCE greater than 10 mg/kg)
(Area: 9,450 sq. ft.)
High Concentration
Groundwater Remediation Zone
(PCE greater than 4,000 ug/L)
(Area: 69,438 sq. ft.)
PCE Isoconcentration Contour
in Shallow Groundwater
(<=25 feet depth)
Using Historical Maximum Values''
1,000 ppb
p1,000 ppb^
1,0 O^ppb^
~
<§>
~
PCE Isoconcentration Contour in
Deep Groundwater (>25 feet depth)
Using Historical Maximum Values2
MVS-Modelled 1,000 ppb
PCE Isoconcentration Contour^
(Area: 158,000 sq. ft.)
MVS-Modelled 2,000 ppb
PCE Isoconcentration Contour^
(Area: 95,731 sq. ft.)
MVS-Modelled 10,000 ppb
PCE Isoconcentration Contour ^
(Area: 47,421 sq. ft.)
MVS-Modelled 20,000 ppb
PCE Isoconcentration Contour 3
(Area: 36,260 sq. ft.)
Mass Discharge Performance
Monitoring Location
Creek Channel Soil Sample
Monitoring Well
Monitoring Well/Recovery Well
(J Private Well
• Reconnaissance Boring
Surface Water
Notes:
1. Shallow aquifer contour from Remedial Investigation (CDM Smith, September 2011) showing maximum historic values.
2. Deep aquifer contour from Remedial Investigation (CDM Smith, September 2011) showi n9 maximum historic values.
3. MVS modeled contours using only the most recent available data from a given locations (Appendix A),
Acronyms:
MVS -m ining visualization system
HRIA -Ham ''ton Labree Impact Area kg -^ilogram
OU1 "O perable Unit 1 sq -s quare
mg -mj lligram
MW -m onitoring well
PW -pr ivate well
ft -f eet
ug -m icrogram
L-jiter vv-cr
PCE etrachloroethene RS -r econnaissance boring
SW
CC-
surface water
eek channel
oEPA
REGION 10
Hamilton / Labree Roads
Superfund Site
Hamilton Road
Impacted Area (HRIA)
MW-607 ©
©
MW-R11
100 0 100
I 1 1 I I
Feet
Sources:
1 Image from © 2011 Google '1
Figure 6-2
Proposed Remediation Target Zones
Breen Property
Harniltoi
1
i
! ^
1,000 ppb
RS-1
%
MW-2
RS-46
RS\18
MW-23
-«V
Bnrcffli
MW-3
PW-3
-------
[SBgH)7i
Unnamed Ditch #1
Approximate Location
for Stream Diversion
iMW-6021
Unnamed Ditch #2
¦ /jr
& jBLvUr>t
^ hi
> r
GP-120
MW
MW-1
\m -
8
MW
Hamilton Road
Impact Area (HRIA)
Acronyms:
AB "auger bor in9
B - soil "boring
mg - milligram
j
BS -s tream bed sediment
MW - monitoring well
CTS -Q omprehensive Treatment Scenario
MVS -|y|j ning Visualization System
GP "geoprobe bor 'n9
OU "operabl e un''
GCL - geosynthetic clay liner
PCE -tetrac hloroethene
Vpu
HRIA-h amiliton Road Impacted Area
Rl - remedial investigation
kg -k ilogram
SB -s tream bank soil
L "lit er
ug -mj crograms
Ji
Legend
[ j HRIA0U1 Boundary
Area of Creek Bed
Sedimentary / Soil Removal
Replaced by Stream Habitat
Underlain by Geosynthetic
Clay Liner (GCL)
Creek Bed Sediments/Bank
Surface Soil Remediation Zone
(PCE greater than 0.468 mg/kg)
High Concentration
Groundwater Remediation Zone
(PCE greater than 4,000 ug/L)
Subsurface Soil
Remediation Zone
(PCE greater than 10 mg/kg)
Stream Diversion
ab5 Auger Boring
ab-651 4 Auger Boring
B2 © Soil Boring
bs-462 ¦ stream Bed
gp3 ¦ Geoprobe Boring
gp-111 m Geoprobe Boring
gp-511 a Geoprobe Boring
Mw-13 ® Monitoring Well
sb-411 x Stream Bank
i Vapor Recovery Well*
8 Thermal Heating Electrodes*
® Temperature Monitoring Point*
• Bioremediation Injection Wells*
Notes:
1. MVS modeled contours using only the most recent
ailable data from a given locations (Appendix A).
2%lonitoring wells and recovery wells located within
ume will be abandoned prior to implementation
the plRH
$¥femediation target zones based on MVS-modeled
ontaminant extents in sediment, soil and groundwater.
4? * = Locations approximate, exact locations to be
ned by contractor.
S^^WSioped from CDM Smith Rl Report (2011).
6. Image from ©2011 Google™
Figure 7-1
Comprehensive Treatment
Scenario (CTS) 2
Conceptual Remedial Configuration
&EPA
REGION 10
Hamilton / Labree Roads
Superfund Site
-------
SB-406
BS-451
AB11
SB-40&
Unnamed Ditch #1
'SEMQi
Approximate Location
for Stream Diversion
"GPA4
SB-400
B *
GP-504
GPA3
- Unnamed Ditch #2
siSKM
BS-160
SB-404
a
e
Acronyms: L -|j( er
AB "auger bori n9 rrig - milligram
B -so il boring MVS -jyjj ning Visualization System
BS -s tream bed sediment MW - monitoring well
CTS - Comprehensive Treatment Scenario OU - operable unit
GP "geoprobe bori n9 PCE - tetrachloroethene
GCL"~ geosynthetic clay liner Rl - remedial investigation
HRIA - Hamilton Road Impacted Area SB -s tream bank soil
kg -|< ilogram ug - micrograms
Legend
J HRIAOU1 Boundary
Area of Creek Bed
Sedimentary / Soil Removal
Replaced by Stream Habitat
Underlain by Geosynthetic
Clay Liner (GCL)
Creek Bed Sediments/Bank
Surface Soil Remediation Zone
(PCE greater than 0.468 mg/kg)
High Concentration
Groundwater Remediation Zone
(PCE greater than 4,000 ug/L)
Subsurface Soil
Remediation Zone
(PCE greater than 10 mg/kg)
Stream Diversion
ab5 + Auger Boring
AB-651 # Auger Boring
B2 © Soil Boring
bs-462 0 Stream Bed
QP313 Geoprobe Boring
GP-111 ~ Geoprobe Boring
GP-511 n Geoprobe Boring
mw-13 ® Monitoring Well
sB-411 * Stream Bank
® Oxidant Injection Locations*
4 Vapor Recovery Well*
* Thermal Heating Electrodes*
® Temperature Monitoring Point*
Notes:
1. MVS modeled contours using only the most recent
ailable data from a given locations (Appendix A).
SMVIonitoring wells and recovery wells located within
ume will be abandoned prior to implementation
the pi RH.
S^fbrnediation target zones based on MVS-modeled
ontaminant extents in sediment, soil and groundwater
£ * = Locations approximate, exact locations to be
. . - ned by contractor.
5. Beveloped from CDM Smith Rl Report (2011).
6. Image from ©2011 Google™
Figure 7-2
Comprehensive Treatment
Scenario (CTS) 3
Conceptual Remedial Configuration
oEPA
REGION 10
Hamilton / Labree Roads
Superfund Site
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