PB97-964613
EPA/541/R-97/201
January 1998
EPA Superfund
Record of Decision:
Old Navy Dump Manchester Laboratory
(USEPA/NOAA)
Manchester, WA
9/30/1997
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RECORD OF DECISION
Manchester Annex
Superfund Site
Manchester, Washington
Prepared for
U.S. Army Corps of Engineers
Seattle District
Contract No. DACA67-93-D-1004
Delivery Order No. 26
September 1997
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CONTENTS Page
ACRONYMS AND ABBREVIATIONS iv
DECLARATION D-1
Site Name and Location D-i
Statement of Basis and Purpose D-1
Assessment of the Site D-1
Description of the Selected Remedy D-1
Statutory Determinations D-3
DECISION SUMMARY 1
1.0 OVERVIEW 1
2.0 SITE LOCATION AND DESCRIPTION 1
3.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES 2
4.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION 4
5.0 SCOPE AND ROLE OF RESPONSE ACTION 6
6.0 SUMMARY OF SITE CHARACTERISTICS 6
V
6.1 Landfill and Clam Bay Sediments 8
6.2 Fire Training Area 10
6.3 Net Depot and Manchester State Park 12
7.0 SUMMARY OF SITE RISKS 12
7.1 Human Health Risks 12
7.2 Ecological Risks 18
8.0 REMEDIAL ACTION OBJECTIVES 19
8.1 Need for Remedial Action 19
8.2 Landfill Area and Clam Bay 20
8.3 Fire Training Area 21
8.4 Net Depot and Manchester State Park 22
8.5 Groundwater 23
8.6 Remediation Areas and Volumes 23
9.0 DESCRIPTION OF ALTERNATIVES 23
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CONTENTS (Continued) Page
9.1 Alternatives for the Landfill and Clam Bay Sediments 23
9.2 Alternatives for the Fire Training Area 2 7
9.3 Alternatives for the Net Depot and Manchester State Park 28
10.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES 28
10.1 Evaluation of Landfill and Clam Bay Alternatives by Criteria 29
10.2 Evaluation of Fire Training Area Alternatives by Criteria 3 3
11.0 THE SELECTED REMEDY 3 5
11.1 Excavation of Intertidal Debris and Placement of Design Fill 3 5
11.2 Placement of Thick Sand Cap over Silt Basin Sediments 36
11.3 Placement of Thin Cap over Remaining Surficial Sediments 3 6
Exceeding Cleanup Levels
11.4 Installation of Landfill Cap and Hydraulic Cutoff System 3 7
11.5 Excavation/Disposal of Dioxin-Contaminated Debris and Soil 38
11.6 In-Place Closure of USTs 38
11.7 Institutional Controls 3 9
12.0 STATUTORY DETERMINATIONS 40
12.1 Protection of Human Health and the Environment 41
f 2.2 Compliance with Applicable or Relevant and Appropriate Requirements 41
12.3 Cost Effectiveness 44
12.4 Utilization of Permanent Solutions and Alternative Treatment 45
Technologies or Resource Recovery Technologies to the Maximum
Extent Practicable
12.5 Preference for Treatment as Principal Element 45
13.0 DOCUMENTATION OF NO SIGNIFICANT CHANGES 45
14.0 REFERENCES 45
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CONTENTS (Continued) Page
TACLES
«
1 Listing of Chemicals of Potential Concern, Manchester Annex Site 48
2 Summary of Soil Quality Data for Landfill Area 49
3 Summary of Soil Quality Data for Fire Training Area 51
4 Summary of Soil Quality Data for Net Depot Area 53
5 Summary of Groundwater Quality Data for Landfill Area (Surficial Fill Unit) 55
6 Summary of Groundwater Quality Data for Outwash Channel Aquifer 56
7 Summary of Seep Quality Data for Landfill Area 59
8 Summary of Surface Water and Seep Quality Data for Fire Training Area 61
9 Summary of Surface Water and Seep Quality Data for Net Depot Area 62
10 Summary of Sediment Quality Data for Clam Bay > 64
11 Summary of Tissue Quality Data for Clam Bay 66
12 Maximum Concentrations Detected in Site Media 67
13 TPH Soil-to-Leachate Ratios in Fire Training Area 68
14 Summary of Cumulative Baseline Cancer Risks and Hazard Indices, 69
Manchester Annex Site
15 Summary of Manchester Annex Cleanup Levels and Cleanup Goals 70
16 Estimated Areas and Volumes Exceeding Soil and Sediment Cleanup Levels 71
FIGURES
1 Vicinity Map
2 Site Features Map
3 Geologic Cross Section
4 Groundwater Elevation Contour Map
5 Conceptual Model - Human Health Risk Assessment
6 Baseline Exposure Pathways
7 Areas Exceeding Soil and Sediment Cleanup Levels in Landfill and Clam Bay
8 Areas Exceeding Soil Cleanup Levels and Goals in Fire Training Area
9 Alternatives 2A and 3A
Approximate Areal Extent of Landfill Cap and Hydraulic Cutoff System
10 Alternative 2A - Armoring over Intertidal Debris, Typical Section
11 Alternative 3A - Excavation of Intertidal Debris and Placement of Design Fill, Typical Section
ATTACHMENT A
RESPONSIVENESS SUMMARY
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ACRONYMS AND ABBREVIATIONS
AET apparent effects threshold
ARAR applicable or relevant and appropriate requirements
BMP best management practice
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
CFR Code of Federal Regulations
COPC Chemical of Potential Concern
Corps U.S. Army Corps of Engineers
CPF Cancer Potency Factor
DoD Department of Defense
Ecology Washington State Department of Ecology
EPA U.S. Environmental Protection Agency
FS Feasibility Study
FUDS Formerly Used Defense Site
CSA General Services Administration
IAG Interagency Agreement
IRIS Integrated Risk Information System
MFS minimum functional standards
MTCA Model Toxics Control Act
NCP National Contingency Plan
NGVD National Geodetic Vertical Datum
NMFS National Marine Fisheries Service
NOAA National Oceanic and Atmospheric Administration
NPL National Priorities List
O&M Operations and Maintenance
PAH Polynuclear Aromatic Hydrocarbon
PCB Polychlorinated Biphenyls
PSDDA Puget Sound Dredge Disposal Analysis
PSNS Puget Sound Naval Shipyard
QA/QC quality assurance/quality control
RAO Remedial Action Objective
RCRA Resource Conservation and Recovery Act
RCW Revised Code of Washington
RfD Reference Dose
Rl Remedial Investigation
RI/FS Remedial Investigation/Feasibility Study
RME reasonable maximum exposure
ROD Record of Decision
SARA Superfund Amendments and Reauthorization Act
SMS Sediment Management Standards
SPLP Synthetic Precipitation Leaching. Procedure
SQS Sediment Quality Standards
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SWQS
TBC
TCLP
TPH
UCL
USFWS
USGS
UST
WAC
WDFW
u,g/kg
mg/kg
mg/L
State Water Quality Standards
to-be-considered
Toxicity Characteristic Leaching Procedure
Total Petroleum Hydrocarbon
Upper Confidence Limit
U.S. Fish and Wildlife Service
United State Geological Survey
Underground Storage Tank
Washington Administrative Code
Washington State Department of Fish and Wildlife
micrograms per kilogram
equivalent to parts per billion (ppb)
milligrams per kilogram
equivalent to parts per million (ppm)
micrograms per liter
equivalent to parts per billion (ppb)
milligrams per liter
equivalent to parts per million (ppm)
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RECORD OF DECISION
MANCHESTER ANNEX SUPERFUND SITE
MANCHESTER, WASHINGTON
DECLARATION
Site Name and Location
Manchester Annex Superfund Site
Manchester, Washington
Statement of Basis and Purpose
This decision document presents the selected remedial action for the Old Navy
Dump/Manchester Annex Superfund Site (Site) in Manchester, Washington. This
remedial action was selected in accordance with the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA), as
amended by the Superfund Amendments and Reauthorization Act (SARA), and,
to the extent practicable, the National Oil and Hazardous Substances Pollution
Control Contingency Plan (NCP). This decision is based on the Administrative
Record for the site.
The remedy was selected by the U.S. Army Corps of Engineers (Corps) and the
U.S. Environmental Protection Agency (EPA). The Washington State Department
of Ecology (Ecology) concurs with the selected remedy.
Assessment of the Site
Actual or threatened releases of hazardous substances from the Site, if not
addressed by implementing the response action selected in this Record of
Decision (ROD), may present an imminent and substantial endangerment to
public health, welfare, or the environment.
Description of the Selected Remedy
The selected remedy is the only response action planned for the Site. This action
addresses all contaminated media at the Site, and consists of the following
actions:
* Landfill debris located in the intertidal zone of Clam Bay will be excavated to
the extent necessary to establish a stable shoreline protection system, with a
goal of no net loss of aquatic habitat. Excavated material will be placed, to
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the extent possible, on the upland landfill area prior to capping. Debris that
is unsuitable for placement on the landfill will be tested for waste
designation purposes and disposed of in an appropriate off-site landfill.
» The shoreline excavation backfill will be designed to achieve seep cleanup
levels, provide the best possible habitat for marine organisms, and maximize
long-term beach stability. Seeps associated with discharge from the landfill
after implementation of the remedial action, if observed, will be monitored
for compliance with seep discharge cleanup levels. Additional remedial
measures will be implemented, as necessary, if seep discharge cleanup levels
are not achieved.
* A thin cap of clean sediment will be established over intertidal Clam Bay
sediment areas which exceed cleanup levels (roughly 5 acres). The overall
goal is to reduce contaminant concentrations in surficial sediments
sufficiently to assure that sediment dwelling organisms are adequately
protected to support unrestricted use of the cap area within several years of
completion of the remedial action. Clam Bay sediment and shellfish tissue
will be monitored in intertidal areas currently exceeding the PCB cleanup
goal for sediments (40 ug/kg [dry]) until compliance with cleanup goals is
established, or until the Washington State Department of Health and the
Suquamish Tribe determine that the shellfish are safe for subsistence-level
harvesting, whichever comes first
* The upland portion of the landfill will be capped in accordance with the
State of Washington's Minimum Functional Standards (MFS) for solid waste
landfill closures. A hydraulic cutoff system will be installed upgradient of the
landfill area. After completion of upland construction, the area will be
revegetated, consistent with long-term O&M requirements and site
development plans. A post-closure plan for the landfill cap, hydraulic cutoff
system, and shoreline protection system will be developed during remedial
construction and implemented following construction.
* Dioxin-contaminated debris will be removed from the main simulator
complex in the Fire Training Area and disposed of in a RCRA hazardous
waste landfill. If routes of potential leakage are found in the simulator floors,
soils beneath the simulators will be sampled and analyzed for dioxins. If
dioxin concentrations above cleanup levels are detected, the simulator(s)
will be demolished, and the underlying contaminated soils excavated.
+ Near-surface soils adjacent to the main simulator complex and the
soil/debris pile north of the main complex will be sampled and analyzed for
dioxins. Soil and debris with concentrations above cleanup levels will be
excavated, tested for waste designation purposes, and disposed of in
appropriate off-site landfills.
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"Concrete USTs remaining in the Fire Training Area will be closed in-place
following state UST closure requirements. UST piping systems, and TPH-
impacted soil excavated incidentally along with the piping, will be disposed
of in an appropriate off-site landfill.
The following institutional controls will be implemented:
Deed covenants to provide for the long-term protection and
maintenance of the selected remedy;
A restriction on subsistence-level harvesting of shellfish until the
Washington State Department of Health and the Suquamish Tribe
determine that the shellfish are safe for subsistence-level harvesting; and
An institutional control plan to address TPH-impacted soil left in-place in
the Fire Training Area.
Statutory Determinations
The selected remedy is protective of human health and the environment,
complies with federal and state requirements that are legally applicable or
relevant and appropriate to the remedial action, and is cost-effective. This
remedy utilizes permanent solutions and alternative treatment or resource
recovery technologies to the extent practicable. However, because treatment of
the principal threat at the site was not found to be practicable, this remedy does
not satisfy the statutory preference for treatment as a principal element of the
remedy. Because this remedy may result in hazardous substances remaining on
site above health-based levels, reviews will be conducted at 5-year intervals, at a
minimum, or as required based on the performance evaluation criteria
contained herein, to ensure that the remedy continues to provide adequate
protection of human health and the environment
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Signature sheet for the foregoing Manchester Annex Record of Decision between the Department
of the Army and U.S. Environmental Protection Agency.
4M£
3 0 SEP 1397
Date
Atting ChievEnvirortmental Division
DirectorateTSfMHitary Programs
United States Army Corps of Engineers
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Signature sheet for the foregoing Manchester Annex Record of Decision between the Department
of the Army and U.S. Environmental Protection Agency.
#
Chuck Clarke Date
Regional Administrator, Region 10
United States Environmental Protection Agency
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DECISION SUMMARY
1.0 OVERVIEW
This Decision Summary provides a description of the site-specific factors and
analyses that led to selection of the remedy for the Old Navy Dump/Manchester
Annex Superfund Site (Site). It includes information about the Site background,
the nature and extent of contamination, the assessment of human health and
environmental risks, and the identification and evaluation of remedial
alternatives.
The Decision Summary also describes the involvement of the public throughout
the process, along with the environmental programs and regulations that may
relate to or affect the alternatives. The Decision Summary concludes with a
description of the remedy selected in this Record of Decision (ROD), and a
discussion of how the selected remedy meets the requirements of the
Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA), as amended by the Superfund Amendments and Reauthorization Act
(SARA).
Documents supporting this Decision Summary are included in the
Administrative Record for the Site. Key documents include the Final Remedial
Investigation/Feasibility Study (RI/FS) and the Proposed Plan for Site Cleanup.
2.0 SITE LOCATION AND DESCRIPTION
The Site is located approximately 1 mile north of Manchester, Washington, in
Kitsap County (Figure 1). The 40-acre site is situated on the western shore of
Clam Bay, an embayment off the west side of Rich Passage in Puget Sound
(Figure 2). Clam Bay is typical of shallow sand-mud marine communities in Puget
Sound, and supports a variety of marine resources. Commercial and
experimental salmon farms also operate in the Bay.
The Site was historically owned and operated by the U.S. Navy for submarine
net maintenance, fire training, and waste disposal activities. Current Site owners
include the U.S. Environmental Protection Agency (EPA) and the National
Oceanic and Atmospheric Administration (NOAA); both of which operate
laboratory facilities at the Site. Approximately TOO personnel work at the two
laboratory facilities. Washington State Parks operates Manchester State Park, a
seasonal park facility, on the extreme western portion of the Site.
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The EPA Manchester Laboratory is situated in the northern 17.5 acres of the Site.
The northernmost 5 acres of the EPA property includes the EPA laboratory and
associated concrete parking pad and other facilities, and is also the location of
the former Navy Net Depot The remaining 12.5 acres, located in the central
portion of the Site, contains a landfill area. A small portion of the northwestern
corner of the landfill area extends onto Manchester State Park property.
The southern 22.5 acres of the Site was the location of a former Navy Fire
Training School and is currently occupied by the NOAA National Marine
Fisheries Service (NMFS). The U.S. Naval Fuel Supply Center is located south of
the Site.
The Site is relatively flat, sloping to the east at roughly a 1 percent grade. Apart
from the concrete parking pad in the north and the existing EPA and NMFS
buildings, most of the Site's surface is vegetated with grasses, shrubs, and
bushes. A localized wetland area exists at the southern end of the landfill, and an
emerging wetland area may exist on the landfill itself. Along the northwestern
portions of the NOAA property, and west and north of the Site in general, the
terrain becomes hilly and forested.
Listed and candidate threatened and endangered species identified at the Site
include the great blue heron, bald eagle, and Steller's sea lion. No archeological
or historical resources have been identified at the Site. However, according to
the Cultural Resources Reconnaissance report prepared for the Site, there is a
moderate probability for hunter-fisher-gatherer cultural deposits.
3.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
The Site was originally established as part of a 385-acre military reservation in
1898, and subsequently transferred from the War Department to the Navy in
1919. During World War II, the Net Depot and Fire Fighting School were
established at the Site. These activities, and the landfill disposal history, are
summarized below.
* Net Depot. From approximately 1940 to the early 1950s, the Manchester
Net Depot functioned to construct, repair, and store submarine nets, made
of steel cable and suspended from gate vessels across strategically important
waterways such as Rich Passage, which guards the Puget Sound Naval
Shipyard at Bremerton. The Net Depot was comprised of a large concrete
pad and various structures including storage facilities and a paint and
sandblasting building. Activities performed within this area of the Site
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included net and buoy maintenance, sandblasting, painting, and machining
operations. The Net Depot appears to have been disestablished in the early
1950s, when the area became devoted to boat storage.
* Fire Training Area. Formally established in 1942, the initial purpose of the
Fire Fighting School was to train World War II Navy personnel to extinguish
ship fires. The school included a number of features which enabled typical
ship fires to be set and extinguished, such as ship compartment simulators,
"Christmas trees," and "smothering tanks." Christmas trees and smothering
tanks typically consisted of small, bermed concrete pads with metal
superstructures for igniting waste oil for fire-training activities. Associated
equipment included underground storage tanks (USTs) for gas, diesel, and
waste oil; fuel lines; water lines; and pumps. Although the Fire Fighting
School was formally disestablished immediately following World War II, its
use may have continued during the 1950s and possibly also during the early
1970s. Three steel USTs were removed in 1994; however, at least five
concrete USTs and several concrete simulators remain in this area.
* Landfill Area. Between approximately 1946 and 1962, the Navy filled the
tidal lagoon between the Net Depot and Fire Training Area. The majority of
the landfilling appears to have occurred between 1946 and 1955. The bulk
of the waste included building demolition debris and burnable garbage from
the Puget Sound Naval Station, along with scrap metals, steel, old submarine
nets, and other debris. The resulting landfill, which has an average thickness
of 6 feet and covers about 6 acres, was subsequently covered with a 1 -foot
thickness of sand and gravel. The southeastern edge of the landfill
(approximately 1,200 feet in length) is currently exposed along the Clam Bay
shoreline, and landfill waste materials have eroded into the adjacent
intertidal area.
The Navy surplused 150 acres of the Station (the former Naval Station property
other than the fuel depot) to the General Services Administration (GSA) in 1960,
though Navy use reportedly continued to about 1962. In 1967, GSA transferred
the Net Depot and most of the Landfill Area to the Public Health Service, and
the property subsequently fell under EPA control. The Fire Training Area was
transferred in 1968 to the U.S. Fish and Wildlife Service (USFWS), and is now
under the administration of the NOAA/NMFS. The portion of the Station located
north and northwest of the EPA and NMFS properties, including a small portion
of the Landfill Area, was transferred to the State of Washington in 1970,
becoming Manchester State Park.
Several investigations including preliminary assessments, site investigations, and
a UST removal and closure action were performed by the U.S. Army Corps of
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Engineers (Corps), EPA, and NOAA during the period from 1987 to 1994. Based
en the findings of these investigations, the Manchester Annex Site was listed in
1994 on the CERCLA (Superfund) National Priorities List (NPL) of Hazardous
Sites. Since historical Department of Defense (DoD) operations appear to be the
sole cause of the contamination present at the Site, CERCLA activities are being
conducted under the Formerly Used Defense Site (FUDS) program. Cleanup
costs will be paid from a special fund set aside for properties formerly used by
DoD.
The RI/FS for the Manchester Annex Site, completed in December 1996, was
conducted by the Corps with oversight by EPA pursuant to the Interagency
Agreement (IAC).
4.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION
Sections 113(k)(2)(b) and 117(a) of CERCLA set forth minimum requirements for
public participation at sites listed on the NPL. The Corps and EPA have met
these requirements and maintained an active community relations program at
the Site.
The Community Relations Plan for the Site is presented in the RI/FS Project
Management Plan, available for review in the information repositories (see
below). The Corps and EPA developed this Plan from discussions with state and
federal agencies, elected officials, community residents, and business and
interest group representatives. These interviews helped identify community
concerns and interests about the Site, and helped define the best ways to work
with the community during the investigation and cleanup.
Community participation has been promoted through the following activities:
* A briefing for laboratory employees who work at the Site, prior to beginning
the RI/FS;
* Creation of the Manchester Annex Work Croup, an advisory group
consisting of representatives from the Corps, EPA, the Washington State
Department of Ecology (Ecology), local, state, and federal government, tribal
government, interest groups, and the general public. The Work Croup met
approximately quarterly during the RI/FS investigation. Issues raised at these
meetings helped identify community concerns and issues throughout the
investigation process;
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* Issuance of project Fact Sheets and invitation to participate in the
Manchester Annex Work Croup meetings.
The actions taken to satisfy the requirements of the federal law have also
provided a forum for citizen involvement and input to the remedial action
decision.
Project documents have been available for public review at the following
locations:
Manchester Public Library
8067 East Main Street
Manchester, Washington
U.S. Army Corps of Engineers
Seattle District Office
4735 East Marginal Way South
Seattle, Washington
The Administrative Record is on file at the following locations:
EPA Lab
7411 Beach Drive East
Port Orchard, Washington
U.S. Army Corps of Engineers
Seattle District Office
4735 East Marginal Way South
Seattle, Washington
The decision is based on the Administrative Record for this Site.
Notice of the availability of the Proposed Plan, plus notice of a public meeting
and public comment period on the Proposed Plan, was published in local
newspapers. The Proposed Plan'was mailed to interested parties on April 1,
1997. The public comment period lasted from April 2 to May 2, 1997. An
employee briefing of EPA, Ecology, and NMFS laboratory staff on the preferred
remedy was held at the Site on March 31, 1997, and a public meeting held on
April 16, 1997, to answer questions and receive public cortjment.
In total, 54 comments were received by the Corps concerning the Proposed
Plan. The comments are summarized and responses presented in the
Responsiveness Summary (Attachment A) of this document.
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5.0 SCOPE AND ROLE OF RESPONSE ACTION
The selected Remedial Action described in Section 11 of this ROD is intended
to address potential current and future impacts to human health and the
environment resulting from chemical contamination at the Site. The greatest Site
risks are associated with potential skin contact and incidental ingestion of waste
materials containing elevated metals and dioxin/furan concentrations. High
concentrations of these compounds are found in the former landfill waste
materials, simulator debris, and associated soils. There is also a threat of
contaminants, primarily metals and PCBs, migrating from the landfill area into
Clam Bay, where sediments and marine organisms may accumulate
contaminants. The purpose of this response action is to minimize future
exposure to contaminated materials, and to reduce contaminant migration into
Clam Bay.
Environmental response actions, completed prior to this remedy selection
process, have occurred in the Landfill and Fire Training Areas of the Site. The
Navy placed a 1-foot-thick soil cap over the landfill in the late 1950s/eariy
1960s, to minimize direct contact with landfill wastes. Several steel USTs were
removed from the Fire Training Area in 1993 under the direction of the Corps,
along with limited excavation of petroleum-impacted soil.
The remedy described herein is the final response action planned for this Site.
6.0 SUMMARY OF SITE CHARACTERISTICS
This section summarizes information obtained during the RI/FS and previous site
investigations, including sources of contaminants, contaminants of concern,
impacted media, and potential routes of human and environmental exposure.
The validated data from the Rl, along with data collected and validated from
prior investigations, were screened relative to area background or local
reference conditions .and conservative risk-based screening criteria to identify
chemicals of potential concern (COPCs) at the Site. Risk-based criteria used to
screen the sampling data included:
* Model Toxics Control Act (MTCA) cleanup levels for soil, groundwater, and
surface water (Chapter 1 73-340 WAC);
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* State surface water quality standards (Chapter 173-201A WAC) and r'ederal
Clean Water Act criteria (40 CFR 131, the National Toxics Rules);
* EPA Region 3 Screening Levels for soil, water, and fish/shellfish tissue (Smith,
1995);
* Plant and wildlife protection screening values for soils obtained from Will
and Suter (1994) and Oak Ridge National Laboratory (1994); and
* Washington State Department of Ecology (Ecology) Sediment Management
Standards (Chapter 173-204 WAC).
Risk-based screening levels incorporate conservative assumptions for protection
of human health (e.g., one-in-a-million excess cancer risk, hazard quotient of one,
residential and subsistence fisher exposure scenarios) and the environment (e.g.,
no or low adverse effects levels, generally chronic exposure scenarios, no mixing
zone).
Analytes that exceeded the screening levels in any media were identified as
COPCs at the Site. The COPCs identified at the Site include metals, PCBs,
chlorinated pesticides, dioxins and furans, polynuclear aromatic hydrocarbons
(PAHs), and petroleum hydrocarbons. A complete listing of the COPCs
identified through the preliminary risk screening process is presented in Table 1.
Tables 2 through 11 summarize soil, groundwater, surface water, sediment and
tissue quality data collected at the Site, including data on the number of samples
analyzed, their detection frequency and maximum detection, as well as
exceedence frequency of screening levels. Tables 2 through 4 summarize soil
quality data for the three source areas (Landfill, Fire Training, and Net Depot)
identified at the Site. Tables 5 and 6 summarize groundwater quality data for the
former Landfill Area (Surficial Fill unit) and the water supply aquifer (Outwash
Channel Aquifer) near the former Fire Training Area, respectively. Tables 7
through 9 summarize surface water and seep discharge quality data tor the three
source areas of the Site, and Tables 10 and 11 summarize sediment and tissue
quality data for Clam Bay.
A further evaluation of COPCs was performed as part of the risk assessment to
identify the primary chemicals or chemical grouping posing a potential risk to
human health and the environment This evaluation included eliminating COPCs
which were below naturally occurring background concentrations (e.g., certain
metals). The baseline risk assessment (discussed below) identified the following
twelve primary chemicals or chemical groupings at the site (out of the initial list
of COPCs) associated with one or more media (soil, sediment, groundwater.
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surface water, and tissue) at concentrations which exceed risk-based
remediation goals or criteria:
Inorganics Organics
- Arsenic - Polychlorinated biphenyls (total PCBs)
- Asbestos - Polychlorinated dibenzo-p-dioxins and
- Cadmium dibenzofurans (dioxins/furans)
- Copper - 2,4-Dimethylphenol
Lead - Vinyl chloride
- Nickel
- Silver
-Zinc
Maximum concentrations for these twelve chemicals or chemical groupings
detected in each Site medium are summarized in Table 12. Total Petroleum
Hydrocarbon (TPH) concentrations are also included in Table 12. While only
posing a marginal risk at the Site, TPH concentrations in soils at the Site exceed
State of Washington Model Toxics Control Act (MTCA) soil cleanup goals.
For ease of discussion, the major findings of the RI/FS are presented for each of
the following source areas, consistent with the Navy's historical Site use
activities:
» Landfill and Clam Bay Sediments;
* Fire Training Area; and
» Net Depot and Manchester State Park.
Figure 2 illustrates the location of these areas and other major Site features.
6.1 Landfill and Clam Bay Sediments
The landfill encompasses an area of approximately 6 acres, with the majority of
the debris in the uplands area and the eastern portion extending into the Clam
Bay intertidal zone. The physical boundary of the landfill has been delineated by
test pit observations of buried debris. The thickness of the upland landfill debris
generally averages about 6 feet with some portions of the landfill ranging to 12
feet in thickness. Figure 3 presents a generalized geologic cross section through
the Landfill (refer to Figure 2 for the cross section location). The upland debris is
covered by a cap of clean sand and gravel which averages one foot in thickness.
The intertidal landfill debris is exposed in a narrow strip along the shoreline,
about 20 to 50 feet wide and ranging from 1 up to 8 feet thick. The total volume
of the landfill debris (upland and intertidal) and cap material is approximately
70,000 cubic yards.
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As shown on Figure 3, the landfill debris is underlain by a thin layer of surficial fill
and beach deposits overlying a thick sequence of low permeability silt. A
localized zone of saturation occurs within the landfill debris and surficial fill unit,
associated with local precipitation recharge, surface water run-on to the landfill
area, and tidal flushing. The low permeability silt acts as a natural barrier,
preventing the downward movement of landfill leachate to the deeper
groundwater zone. Recharge to the landfill ultimately mixes with leachate in the
landfill and discharges as seeps along the intertidal zone.
Landfill wastes contain elevated concentrations of a variety of metal and organic
chemicals including arsenic, cadmium, copper, lead, nickel, silver, zinc, PCBs,
dioxins/furans, vinyl chloride, and asbestos, as shown in Table 2. Roughly half of
the landfill soil samples analyzed by toxicity characteristic leaching procedure
(TCLP) exceeded lead toxicity criteria. Erosion of landfill waste materials in the
intertidal area of Clam Bay, due to tidal action, represents a continuing source of
contaminants, primarily metals, PCBs, and dioxins/furans, to the marine
environment.
The highest concentrations of chemicals of concern in the sediments and
shellfish tissue, particularly metals and PCBs, were identified in areas
immediately adjacent to the landfill toe. Constituent concentrations decline
rapidly outside the landfill toe area. PCBs, metals (cadmium, copper, lead,
mercury, and zinc), and dioxins were the primary chemicals identified in marine
sediments (Table 10). Chemical analysis of marine tissue, including clams,
geoduck, and sea cucumbers, were also performed. Tissue concentrations in
Clam Bay were above reference site-adjusted screening levels for PCBs, dioxins,
metals, and PAHs (Table 11).
Potential impacts to marine organisms were evaluated by performing laboratory
bioassay tests using contaminated sediments collected at the Site. The bioassay
results indicated moderate adverse effects to the existing benthic infauna within
the intertidal area of Clam Bay.
Impacts to sediment quality within Clam Bay are largely limited to the
uppermost layer of sediments. Two high-resolution coring profiles of PCBs
indicate that the depth of contamination ranges from 0.3 to 0.7 foot, averaging
0.5 foot. A deeper accumulation of contaminated sediments exists in an isolated
area of the intertidal zone. Offshore from the north end of the landfill (just south
of the pier) is a localized (approximately 2,700-square-foot) depression with a
thick (greater than 3-foot) accumulation of fine-grained sediment exhibiting
elevated concentrations of PCBs, copper, zinc, and 2,4-dimethylphenol. This
offshore feature (referred to as the "silt basin") may have resulted from removal
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of an in-water structure, or from local current movement and sediment
deposition patterns.
Seep discharges along the landfill toe, associated with surface water and
precipitation recharge through the landfill as well as tidal flushing, result in the
release of dissolved metals to the nearshore environment. The discharge to
Clam Bay is fairly low, estimated to be in the range of 5 to 8 gallons per minute
across approximately 800 feet of landfill shoreline frontage. Saturated conditions
within the surficial fill and beach deposits beneath the landfill debris largely result
from the local freshwater recharge and tidal inflow. Croundwater flow directions
within the surficial fill unit is shown on Figure 4. The "groundwater" quality in
this unit, summarized in Table 5, is indicative of leachate conditions beneath the
landfill. Leachability tests (TCLP) of landfill debris samples indicated that metals
within the debris are teachable and likely dissolve into recharge water infiltrating
through the waste. Several metals (including copper, nickel, silver, and zinc) and
low-level PCB concentrations (Table 7) were detected in tidal seeps discharging
from the landfill. The seeps contain a component of non-saline groundwater and
a component of seawater which, at high tide, flows into the beach deposits
which underlie the landfill debris, backflushing out at low tide.
6.2 Fire Training Area
Historical activities at the Fire Training Area included fuel storage and firefighting
training. The Fire Training Area previously included three simulator structures,
only one of which (referred to as the "main simulator complex") is still standing.
Accumulations of debris inside the main simulator complex contain elevated
concentrations of dioxins/furans. The internal debris volume is estimated at
approximately 200 cubic yards. Table 3 summarizes soil quality data for the Fire
Training Area.
Significantly lower concentrations of dioxins/furans were also detected in the
following media/locations outside the simulators:
* Surficial Soil in the Immediate Vicinity of the Simulators. The presence ot
dioxins/furans is likely associated with the fallout of ash or burning debris
from the main simulator during training exercises. The depth of
contamination appears to be less than one foot and is limited to several
isolated areas near the corners of the simulator structures, as shown on
Figure 8. Dioxin releases are not likely to have extended under the simulator
structures, except through any possible floor cracks, if they exist. No
sampling and analysis have been performed to verify this condition.
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* Pile of Demolition Debris and Soil Located about 500 Feet North of the
Main Simulator Complex. The demolition debris is associated with the
former northern simulator at this location. The simulator rubble pile (Figure
8) has an estimated volume of approximately 120 cubic yards.
Soils in the vicinity of the main simulator complex also exhibit concentrations of
total petroleum hydrocarbons (TPH), with concentration of up to 15,000 mg/kg
as diesel and 7,700 mg/kg as oil. The TPH consists of a mixture of weathered
diesel- and oil-range hydrocarbons. A number of petroleum-containing USTs
were formerly located in this area, and several are known to have leaked. In
addition, at least five concrete USTs still remain in-place. The remaining concrete
USTs contain residual sludges. Chemical analysis of these sludges during the
tank removal process, prior to the Rl, indicated the presence of PCBs. The
vertical extent of TPH-impacted soils ranged from near-surface to as much as 10
feet below grade.
Smaller areas of TPH concentrations were detected at four former fire training
stations (i.e., smoldering pots and "Christmas trees") north of the main simulator
complex, shown on Figure 8. These areas contained diesel- and oil-range
hydrocarbons which permeated the upper several feet of soil. In addition, soil at
the location of a former gasoline UST contained subsurface hydrocarbon
concentrations in the gasoline range of up to 480 mg/kg.
The TPH-impacted soils within the former Fire Training Area are located near the
Outwash Aquifer which is used by the adjoining Manchester Naval Fuel Depot
and a local community for potable water supply. The general location and
groundwater flow direction within the Outwash Aquifer is shown on Figure 4.
The remedial investigation included extensive data collection and testing to
evaluate the potential impact of the TPH on the Outwash Aquifer. Initial efforts
included chemical analysis and leachability testing of TPH-impacted soils using
the Synthetic Precipitation Leaching Procedure (SPLP). The empirical TPH soil-to-
water partitioning ratios at the site range from 1,000:1 to 7,000:1, and average
5,000:1 (Table 13). These results indicate that the TPH is highly weathered, due
to chemical and biological degradation over a 30-year-plus period since release,
and largely consists of the heavy (very low aqueous solubility) petroleum
fraction. The SPLP data indicate that the remaining petroleum constituents are
not leachable. This conclusion is supported by shallow aquifer monitoring
results, which were generally below screening levels for petroleum constituents.
A summary of the groundwater quality in the Fire Training Area is presented in
Table 5.
In addition, several pumping tests, using the Navy's water supply wells, were
conducted to assess whether pumping the water supply wells would result in the
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transport of petroleum constituents to the aquifer. Sampling of shallow
groundwater beneath the TPH-impacted soils during active pumping did not
identify any petroleum constituents, even at very low level detection limits.
Consequently, the TPH-impacted soils do not pose a risk to nearby public and
private water supply wells.
Diesekange hydrocarbons were detected at a concentration of 5.2 mg/L (and
20 mg/L in a duplicate sample) in one surface water sample collected from the
outflow of a pipe discharging to a pond in the southern portion of the Fire
Training Area. Based on a review of historical site plans, the pipe appears to be
connected to a storm drain system and likely received TPH in runoff from
roadways or parking lots at the NMFS lab. However, the exact source area of
this pipe has not been determined.
6.3 Net Depot and Manchester State Park
Tables 4 and 9 summarize soil and seep discharge quality data for the Net
Depot area. The analytical results for the Net Depot and Manchester State Park
areas of the Site indicated limited exceedence of conservative risk-based
screening criteria. Several metals with concentrations slightly elevated above the
screening levels were detected in these areas, including arsenic (8.6 mg/kg),
beryllium (0.8 mg/kg), copper (71 mg/kg), and zinc (231 mg/kg). Several surface
water/seep samples in the Net Depot area also exceeded screening levels for
dissolved copper (30.6 ug/L) and total cyanide (5 ug/L). These seeps appear to
be associated with drain pipes which may receive storm water runoff from the
parking lot areas.
7.0 SUMMARY OF SITE RISKS
CERCLA response actions at the Site, as described in the ROD, are intended to
protect human health and the environment from current and potential future
exposure to hazardous substances detected at the Site.
Baseline human health and ecological risk assessments were performed to
assess Site conditions and to determine the need for cleanup. As set forth in the
NCP, the risk assessment provides an understanding of the actual and potential
risks to human health and the environment at the Site, in the absence of any
future actions to control or mitigate these releases.
7.1 Human Health Risks
Detailed assessments of the risks to human health involve a five-step process: 1)
identification of chemicals of potential concern; 2) determination of exposure to
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the population(s) at risk; 3) assessment of contaminant toxicity; 4) quantitative
characterization of site risk; and 5) evaluation of uncertainties associated with
the overall risk assessment
7.1.1 Chemicals of Potential Concern
The risk assessment evaluated chemicals detected in at least one sample at a
concentration above the most conservative risk-based screening levels. These
COPCs included seventeen metals and inorganics, ten hydrocarbons, four
pesticides, PCBs, dioxin/furan congeners, and several miscellaneous organic
chemicals. A listing of COPCs detected at the Site is presented in Table 1.
7.1.2 Exposure Assessment
The exposure assessment characterizes exposure scenarios, identifies potentially
exposed populations along with pathways and routes of exposure, and
quantifies contaminant exposure in terms of a chronic daily dose (i.e., milligrams
of contaminant taken into the body per kilogram of body weight per day).
Consistent with recent EPA guidance, human health exposure scenarios
evaluated in the risk assessment were developed based on reasonable
assumptions about future land uses and human activities expected at the Site.
Most of the Site is currently used by EPA and NMFS as an environmental
laboratory facility. In addition, a small portion of the Site is used as a State Park.
Based on input from the Manchester Annex Work Croup, continued use of the
Site for federal laboratories and a State Park was assumed in evaluating potential
human health risks. Assuming future residential use at the Manchester Annex
Site was considered unrealistic.
The conceptual model for chemical release, transport, and human exposure at
the Site is presented on Figure 5, and exposure pathways are illustrated on
Figure 6. Mechanisms for chemical release and exposure at the Site include the
following:
* Direct contact with contaminated soils, sediments, and debris;
* Volatilization, dust emission, and inhalation of chemicals from contaminated
surface soil;
* Solubilization, transport, and drinking water consumption of chemicals in
groundwater;
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* Surface water runoff and tidal erosion of surface soils and sediments into
- waterways; and
* Transport of contaminants to Clam Bay, bioconcentration and
bioaccumulation through the food chain, followed by recreational or
subsistence-level consumption of contaminated seafood.
EPA Superfund guidance recommends that reasonable maximum exposures be
calculated in site risk assessments. Reasonable maximum exposure estimates are
calculated using assumptions that result in higher than average exposures to
ensure that the risk assessment results are protective of the reasonably
maximum exposed individual. For this risk assessment, both average and
reasonable maximum exposures (RME) were estimated using default exposure
factors and calculation procedures described in EPA Region 10 risk assessment
guidance. Average and upper 95th percent confidence limits (UCLs) of the
arithmetic mean chemical concentrations detected at the Site were used to
calculate the concentration terras used in the exposure assessment. If the
estimated UCL exceeded the maximum detected concentration, the estimate
defaulted to the maximum detected concentration.
An individual's exposure to chemicals through activities such as digging in the
soil, or eating shellfish caught at the Site, was estimated assuming that current
controls such as the existing landfill soil cover are not maintained into the future.
Currently, EPA prohibits shellfishing on its beaches, and staff working at the EPA
and NMFS facilities presently obtain six or fewer meals per year from Clam Bay.
This condition is partially the result of the relatively low edible clam biomass at
the Site resulting from habitat limitations. However, on-site recreational and
tribal subsistence harvesting of seafood within Clam Bay could increase in the
future through habitat enhancement Following the recommendations of the
Washington State Department of Fish and Wildlife (WDFW) and the Suquamish
Tribe, the risk assessment evaluated recreational and subsistence harvesting
rates possible under a future habitat enhancement scenario. Reasonable
maximum harvesting rates assumed in the exposure assessment were 22 meals
(3.4 kilograms [kg]) per year and 150 meals (23 kg) per year for recreational and
subsistence consumption, respectively.
7.1.3 Toxicitv Assessment
Toxicity and risk assessments vary for different chemicals depending upon
whether carcinogenic and nonorcinogenic risks are being evaluated. The
toxicity criteria used in risl: assessments are based on the endpoints observed
from laboratory or epidemiological studies with the chemicals. Carcinogenic
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risks are calculated using toxicity factors known as cancer potency factors
(CPFs), while nonorcinogenic risks rely on reference doses (RfDs). When
available, toxicity factors used in this risk assessment were obtained from EPA's
Integrated Risk Information System (IRIS; EPA, 1995a). In the absence of verified
toxicity factors on IRIS, other EPA sources were consulted (Dollarhide, 1992;
and EPA, 1985, 1989, 1993, and 1995b).
Reference Doses (RfDs). Reference doses are used to quantitatively evaluate
non
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were considered protective in non-residential areas. This value was used as a
risk-based soil concentration benchmark criterion for assessing elevated lead
concentrations detected in soil at the site. Lead concentrations of up to 56,000
mg/kg have been detected within the Landfill Area of the Site (Table 2).
TPH. Elevated total petroleum hydrocarbon (TPH) concentrations up to 15,000
mg/kg have been detected in the Fire Training Area of the Site (Table 3).
However, no verified oral toxicity factors have been derived for TPH mixtures.
EPA has developed provisional oral RfDs and CPFs for several TPH mixtures
including gasoline and diesel fuels based on extrapolations of inhalation toxicity,
since few other data were available. In making this provisional determination,
EPA applied conservative uncertainty factors to address some of the possible
bias associated with route-to-route extrapolations. The provisional TPH toxicity
criteria used in this risk assessment are currently under EPA review.
7.1.4 Risk Characterization
For risk characterization purposes, the entire Site was considered in aggregate,
utilizing UCL exposure point concentrations within different areas of the Site to
derive Site-wide RMEs and risks. For cleanup alternative evaluation purposes, the
Site was divided into three different remedial action areas characterized by
different waste characteristics and response actions (see Figure 2 and Section
9.0 below).
For carcinogens, risks are estimated as the incremental probability of an
individual developing cancer over a lifetime as a result of exposure to specific
COPCs. Cancer potency factors are multiplied by the estimated intake
(exposure) of a potential carcinogen to provide an upper-bound estimate of the
excess lifetime cancer risk associated with exposure at that intake level. The
EPA's current guideline for determining whether the reasonable maximum
cancer risk estimated for a given hazardous site exceeds "threshold" cleanup
action levels is 10J (1 in 10,000 probability of developing cancer resulting from
lifetime exposure to a carcinogen). By comparison, the general target for lifetime
cancer risks under MTCA is 10'5. Under both programs, however, a cancer risk
goal of 10"6 is generally used where practicable.
Non-carcinogenic risk is evaluated by dividing the daily dose resulting from site
exposure by the estimate of acceptable intake (or reference dose) for chronic
exposure. If the ratio between these values (termed the hazard quotient) is less
than 1, then the exposure does not exceed the protective level for that particular
chemical. Conversely, hazard quotient values greater than 1 indicate a potential
risk to human health. Under both the CERCLA and MTCA programs, it the sum
of all chemicals' hazard quotients for an exposure medium (termed the hazard
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index) is greater than 1.0, then there may also be a concern for potential health
effects.
Potential health risks to individuals under the following scenarios were
evaluated:
* An on-site worker;
* A subsistence consumer of shellfish; and
* An occasional site visitor (including children).
Both the on-site worker and occasional site visitor (child) had similarly high
calculated health risks, though the visitor scenario had slightly higher risk
estimates. Calculated average and reasonable maximum exposure cumulative
cancer risks and hazard indices for the three different exposure scenarios are
summarized in Table 14. Under RME conditions, a cumulative Hazard Index of
1,000 and a total cumulative lifetime cancer risk of 1 x 10° were calculated
based on the summation of all chemicals and potential pathways at the Site.
Calculated health risks to the on-site worker and occasional site visitor are
primarily associated with potential skin contact and incidental ingestion of waste
materials containing elevated metal and dioxin/furan concentrations. High
concentrations of these compounds are restricted to subsurface landfill waste
materials and simulator debris. In addition, lead concentrations detected within
the landfill areas exceeded the risk-based benchmark concentration for non-
residential sites of 1,000 mg/kg. Based on the risk assessment, soil containing
elevated TPH concentrations was not identified as a threat to human health.
Potential health risks for the subsistence consumer of shellfish, while lower, were
still above concentrations targeted by the State of Washington cleanup program
(MTCA; Table 14). Health risks to the subsistence consumer of shellfish primarily
result from consumption of PCBs in shellfish collected from the intertidal area of
Clam Bay.
7.1.5 Uncertainty in the Human Health Risk Assessment
The overall uncertainty in the human health risk characterization is represented
in part by the differences between the average and reasonable maximum risk
estimates presented in Table 14. A semi-quantitative sensitivity analysis was
performed to identify individual exposure and toxicity assessment assumptions
which contributed most to the overall uncertainty in the risk estimates. The
sensitivity analysis identified five principal areas of uncertainty:
* Representativeness of key soil exposure concentration terms;
* Dermal (skin contact) exposure assumptions and extrapolations;
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* Possible access to the Site by an occasional site visitor;
*_ Toxicity assessment of PCS congeners; and
* Risk characterization using cancer risk models.
Most assumptions incorporated into the baseline risk assessment were .
intentionally conservative so that the risk assessment would be more likely to
overestimate rather than to underestimate risk. However, in some cases the
nature of the uncertainty is such that the impact of the assumptions could result
in an overestimate or underestimate of Site risk.
7.2 Ecological Risks
An ecological risk assessment was performed to characterize current and
potential future environmental threats at the Site, particularly to valuable
ecological resources such as Clam Bay habitats. The assessment which
addressed both aquatic and terrestrial exposures, incorporated a two-tiered
approach. In the Tier I assessment concentrations of chemicals of potential
concern were compared to toxicological benchmarks which represent
concentrations of chemicals in environmental media (i.e., soil, water, sediment,
and biota) that are presumed to be non-hazardous to the surrounding biota. Tier
I relied on chemical concentration measurements and conservative toxicity
benchmark criteria available in the literature. Based on Tier I results, the need for
and scope of more definitive Tier II biological evaluations were determined. Tier
II incorporated Site-specific information as appropriate, and included biological
sampling to support or refute the Tier I findings.
The ecological assessment identified metals, PCBs, and furans in the Landfill
Area which have the potential to impair microbial and soil processes, inhibit
plant growth, and/or could result in toxicity to earthworms and sensitive small
rodents which inhabit the Site. Several of these metals are also currently
discharging from the landfill shoreline area at concentrations which could result
in acute and/or chronic toxicity to sensitive marine life. Because of tidal currents
and associated mixing processes, the extent of elevated metal concentrations
within the shoreline area of Clam Bay is likely limited to the immediate vicinity of
the seepage face and seepage channels.
Metals, PCBs, and 2,4-dimethylphenol were detected in intertidal sediments of
Clam Bay at concentrations which could result in toxicity to sensitive marine
infauna. Confirmatory sediment bioassays generally confirmed this condition.
Further, elevated metals, PCS, and furan concentrations detected in intertidal
shellfish could pose a risk to wildlife which derive their entire diet from prey
obtained from Clam Bay. Overall, potential risks to the environment at the Site
are limited to the Landfill Area and to the intertidal area of Clam Bay.
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Detection limits for mercury, PCBs, DDT, aldrin, and dioxins in seeps were not
sufficient to evaluate risk to marine aquatic life. However, these chemicals were
incorporated in the ecological risk assessment at one-half detection limit values.
Some other chlorinated pesticides were also undetected at elevated detection
limits, but were not incorporated in the risk assessment potentially causing a
slight underestimate of the overall risk to aquatic life. Similarly, detection limits
for several chlorobenzene compounds were not sufficient to compare with
ecological sediment criteria. However, Tier II bioassay testing of Site sediments
provided a direct measure of cumulative risk from all Site contaminants.
8.0 REMEDIAL ACTION OBJECTIVES
8.1 Need for Remedial Action
The results of the baseline human health and ecological risk assessments
indicate that potential long-term risks associated with soil and debris in the
Landfill and Fire Training Areas, and sediment contamination in Clam Bay, are
above acceptable concentrations defined under both the state (MTCA) and
federal (Superfund) regulations. Actual or threatened releases of hazardous
substances from this Site, if not addressed by remedial actions, may represent a
current or potential threat to public health, welfare, or the environment.
Consistent with the NCR and EPA policy, remedial action is warranted to
address these potential risks.
This Record of Decision makes a distinction between cleanup levels and
cleanup goals. Cleanup levels represent specific concentration limits to protect
human health and the environment, as defined by the Site-specific risk
assessment and in applicable or relevant and appropriate regulations (ARARs).
Table 15 presents a listing of Site-specific cleanup levels and cleanup goals.
Remedial alternatives were developed for the Manchester Annex Site to attain
these cleanup levels.
In contrast, cleanup goals are conceptual targets for additional Site-specific
cleanup of two key contaminants: TPH and PCBs. The soil cleanup goal for
diesel and oil-range TPH as defined by-MTCA is 200 mg/kg. However, because
of the low teachability and low risk associated with TPH at the site, attainment of
this goal is not necessary to provide protection of human health and the
environment. Nevertheless, where practicable, additional operations and
maintenance controls may be appropriate to further reduce TPH-related risks.
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Although sediment cleanup levels for the Manchester Annex Site were based on
the existing recreational exposure condition, sediment and tissue cleanup goals
for PCBs were developed assuming a possible long-term subsistence fishing use
of Clam Bay (Table 15). Both sediment and shellfish concentrations are
predicted to decline rapidly following remediation to the recreational-based
cleanup levels. Risks associated with subsistence fishing can be controlled by
implementing temporary limitations on subsistence-level consumption during
the initial recovery period. In this case, monitoring would be performed to verify
attainment of the cleanup goals.
8.2 Landfill Area and Clam Bay
The human health and ecological risk assessment identified potential threats
associated with a variety of metal and organic chemicals detected within the
Landfill Area. Based on the risk assessment, the following remedial action
objectives were developed for the Landfill and Clam Bay areas of the Site:
* Prevent human and wildlife contact with solid wastes and soils/sediments in
the landfill;
* Prevent fugitive dust emissions containing asbestos;
* Prevent shoreline erosion of landfill wastes;
* Reduce solubilization and migration of landfill contaminants to Clam Bay by
eliminating seeps or by improving the quality of the seeps so that they meet
water quality criteria;
* Reduce concentrations of metals, PCBs, and 2,4-dimethylphenol to below
cleanup levels for sediments in the biologically active zone (0 to 10 cm
depth); and
+ Prevent subsistence-level harvesting of shellfish in the nearshore areas of
Clam Bay until the shellfish are determined to be safe to consume at a
subsistence level.
Instead of establishing numerous chemical-specific cleanup levels for soils and
solid wastes present within the upland and shoreline areas of the Site, the
presumptive remedy for military landfills (capping) was first applied to the Site to
determine if this presumptive remediation approach could achieve most or all of
the identified remedial action objectives. The area to be contained within the
cap was initially determined based on the physical extent of landfill debris. The
extent of solid wastes at the Site is depicted on Figure 7.
To evaluate the protectiveness of the presumptive remedy applied to the Landfill
Area, the residual risk associated with soils and sediments located immediately
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adjacent to the landfill area (i.e., outside the footprint of the presumed capping
area) was calculated using methodologies equivalent to those used in the
baseline risk assessment. The results of this assessment reveal that, even under
RME conditions, risks to on-site workers, occasional site visitors, and terrestrial
wildlife would be below both MTCA and CERCLA risk goals (i.e., cancer risks
below 1 x 10'5, Hazard Index below 1, and no identified risk to the upland
environment). The presumptive remedy is therefore adequately protective of
upland exposure conditions within the Landfill Area.
While the presumptive remedy of landfill capping would also achieve substantial
risk reductions for existing or potential receptors in Clam Bay (i.e., aquatic life
and subsistence fishers), this action may not be sufficient by itself to achieve all
of the identified remedial action objectives within the marine environment.
Accordingly, chemical-specific cleanup levels and cleanup goals were developed
for aquatic exposure pathways which will achieve overall risk management goals
as follows:
* A cumulative cancer risk goal under future RME conditions of 1 x 105
(MTCA Method C criterjon), considering combined seafood ingestion,
sediment contact, and incidental sediment ingestion pathways;
* A cumulative hazard index under future RME conditions of 1, also based on
a cumulative pathway analysis;
* No identified risk to aquatic biota and other wildlife; and
* Compliance with applicable or relevant and appropriate requirements
(ARARs), including State of Washington surface water quality standards
(Chapter 173-201A WAC) and sediment management standards (Chapter
1 73-204 WAC).
The cleanup levels and cleanup goals relevant to the Landfill and Clam Bay areas
of the Site are summarized in Table 15.
8.3 Fire Training Area
Besides the Landfill/Clam Bay area, the only other area of the Site which poses
an identified risk to human health and the environment is the Fire Training Area
(Figure 8). The risk assessment identified potential threats associated with
dioxin/furan congeners detected primarily within the simulator areas. Based on
the risk assessment, the following remedial action objectives were developed for
the Fire Training area:
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* Prevent human and wildlife contact with simulator debris and soils
"containing dioxin/furan concentrations greater than the cleanup level; and
* Minimize solubilization and migration of TPH into groundwater.
As discussed above, the Site is not an existing or potential future residential site,
nor does the Site qualify as an industrial site under the MTCA cleanup
regulation. Chemical-specific cleanup levels and cleanup goals were developed
for this upland area of the Site using the baseline risk assessment along with the
following risk management goals:
* A cumulative cancer risk goal under future RME conditions of 1 x 105
(MTCA Method C criterion), considering cumulative soil contact incidental
soil ingestion, inhalation, and drinking water pathways;
* A cumulative hazard index under future RME conditions of 1, also based on
a cumulative pathway analysis; and
+ Compliance with ARARs including State of Washington MTCA Method C
soil cleanup levels for non-industrial sites (WAC 173-340-740).
The cleanup levels and cleanup goals relevant to the Fire Training Area are
summarized in Table 15. A soil cleanup goal for TPH (as diesel) was established
for this area of the Site based on the MTCA Method A (routine) cleanup level.
However, since the site-specific risk assessment and leachability testing indicated
only a low risk from TPH, no chemical-specific cleanup level is necessary.
8.4 Net Depot and Manchester State Park
Baseline risks within the former Net Depot (current EPA laboratory) and
Manchester State Park areas of the Site were determined to be below both
human health and environmental risk management goals (i.e., cancer risks below
1 x 10"5, Hazard Index below 1, and no identified risk to the upland
environment). Consolidation of relatively small quantities of solid waste from the
Manchester State Park to the current EPA property is anticipated as a result of
the presumptive remedy (landfill capping), primarily because the presence of a
utility corridor which runs along the property boundary may interfere with
remediation if the wastes are not relocated. (Construction of the cap over the
utility corridor should be avoided. As an alternative to waste consolidation, the
utility corridor may be relocated.) Accordingly, no further remedial action
objectives were developed for the Net Depot and Manchester State Park areas
of the Site.
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8.5 Groundwater
Currently, water supply for the NMFS and EPA facilities is provided by an off-site
source. With the exception of the Outwash Aquifer, near the Fire Training Area
at the southern edge of the Site, groundwater present throughout the Site is not
a current or potential source of water supply. No chemicals have been detected
at concentrations above risk-based and aesthetic screening levels in shallow
groundwater below the Fire Training Area or within the Outwash Aquifer. The
Fire Training Area is the only area at the Site which occurs near the water supply
aquifer (Outwash Aquifer). The low potential risk to human health associated
with groundwater at the Site was also confirmed by the site-specific risk
assessment (cancer risk less than 10"6; hazard index less than 0.3). Accordingly,
no remedial action objectives were developed for Site groundwater, outside of
the seep cleanup levels applicable to the landfill shoreline area (see Table 15).
8.6 Remediation Areas and Volumes
Areas exceeding soil and sediment cleanup levels in the Landfill/Clam Bay
portion of the Site are shown on Figure 7. Areas exceeding soil cleanup levels
and cleanup goals in the Fire Training Area are shown on Figure 8. (The Net
Depot and Manchester State Park areas of the Site comply with all cleanup
levels.) Site-wide area and volume estimates for all media exceeding soil and
sediment cleanup levels are provided in Table 16. The entries in this table reflect
further refinement of the areas and volumes presented in Table 3-3 of the
Feasibility Study.
9.0 DESCRIPTION OF ALTERNATIVES
Various cleanup alternatives ranging from no action to complete
removal/treatment of contaminated materials were identified and evaluated in
the Feasibility Study (FS). Area-specific subsets of these alternatives were
considered in the Proposed Plan, as discussed below.
9.1 Alternatives for the Landfill and Clam Bay Sediments
Of the six alternatives evaluated in the FS for cleanup of the Landfill and Clam
Bay sediments, the following four were considered in the Proposed Plan:
(1 A) No Action (FS Alternative A1).
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(2A) Capping of Upland Landfill, Armoring over Intertidal Debris, and
- Placement of a Thin Cap over Remaining Impacted Sediments (FS
Alternative A2).
(3A) Capping of Upland Landfill, Excavation of IntertidaJ Debris and
Placement of Design Fill, and Placement of a Thin Cap over Remaining
Impacted Sediments (FS Alternative A5).
(4A) Excavation/Dredging, Limited Treatment and Off-Site Disposal of All
Landfill Debris, Soils, and Impacted Sediments (FS Alternative A6).
Descriptions of these four alternatives are presented below.
Alternative 1ANo Action. The No Action Alternative provides a baseline
against which to compare the other alternatives to evaluate their effectiveness.
Under this alternative, the Landfill and Clam Bay sediments would be left as they
currently exist.
Alternative 2ACapping of Upland Landfill, Armoring over Intertidal Debris,
and Placement of a Thin Cap over Remaining Impacted Sediments. This
alternative includes capping the upland portion of the Landfill, placing a
hydraulic cutoff system upslope of the cap, placing a rock and cobble armor
over the portion of the Landfill that extends into Clam Bay, and placing a thin
cap over impacted sediments in Clam Bay.
Prior to cap construction, any solid waste located west of the utility corridor
which runs along the EPA/Manchester State Park property boundary would be
excavated and placed on the remaining upland landfill area. (Alternatively, the
utility corridor could be relocated to outside the solid waste area.) The cap
would be designed to meet state Minimum Functional Standards requirements
and be consistent with the long-term plans for the property. The hydraulic cutoff
system would keep groundwater and surface water from entering the Landfill
along its upslope edge. Figure 9 shows the approximate areal extent of the
landfill cap and hydraulic cutoff system.
Armoring of the landfill areas lying within the intertidal zone of Clam Bay would
prevent further erosion of the landfill waste and provide a physical barrier to
keep people and wildlife away from the debris. Figure 10 shows a schematic
cross section of the armor layer. It may be 2 to 3 feet thick and would be filled
with finer grained soils to provide a suitable environment for marine organisms.
The armor layer would raise the elevation of the beach, causing an outward
(seaward) shift in the high water line, and resulting in the loss of up to one acre
of existing aquatic area. Based on input from the Manchester Site RI/FS Work
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Group, measures to mitigate the loss of aquatic habitat would need to be
considered as part of this alternative.
Prior to placement of the armor layer, a cap consisting of clean sediments or
similar material would be placed over the silt basin sediments to isolate them
from the intertidal environment. Sufficient cap material would be placed to fill
the existing depression flush with the surrounding mudline (nominal 2-foot cap
thickness).
Rows of clean sediment (windrows) would be placed over sediments exceeding
sediment cleanup levels in the intertidal zone of Clam Bay which are not
covered by the armor layer or silt basin cap. Tide and wind forces would spread
the clean sediment out naturally and evenly over time. Remaining sediments
with low concentrations of PCBs (exceeding the cleanup goal but posing
minimal risk) are expected to recover rapidly once the source of contamination,
erosion of the landfill waste, is eliminated. The natural recovery of these
sediments, without the thin layer capping of sediments exceeding the sediment
cleanup levels, was predicted to occur largely by burial and resuspension
processes, based on modeling performed during the RI/FS. The addition of clean
sediment in those areas exceeding the sediment cleanup levels should enhance
the recovery of these remaining sediments through burial processes.
Long-term land use restrictions to prevent activities which could damage the
cap, and a cap maintenance program, would be implemented. Potential
construction impacts to the freshwater wetlands adjacent to the southern edge
of the landfill (and to the potential emerging wetlands on the landfill area itself)
would be addressed during final design. Restrictions on subsistence-level
shellfish harvesting would apply until the Washington State Department of
Health and the Suquamish Tribe determine that the shellfish are safe for
subsistence-level harvesting. Unacceptable human health risks of consuming
shellfish were found only at subsistence consumption rates (which are
considerably higher than recreational consumption rates) of shellfish from
tidelands adjacent to the Landfill and Fire Training Area. Sediment and tissue
cleanup goals are predicted to be met 3 to 5 years after remedial construction is
completed. Sediment and shellfish tissue in Clam Bay would be monitored
periodically by the Corps to track recovery.
Any seeps observed during low tides would also be monitored for water quality.
Based on preliminary analysis, placement of the armor layer, installation of the
hydraulic cutoff system, and capping of the upland landfill would likely reduce
the metals concentrations in seep discharge to below cleanup levels. Seep
discharge would be further evaluated as part of the final design.
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Alternative 3ACapping of Upland Landfill, Excavation of Intertidal Debris
and Placement of Design Fill, and Placement of a Thin Cap over Remaining
Impacted Sediments. This alternative is similar to Alternative 2A described
above in terms of capping of the upland Landfill, except that landfill debris in the
intertidal zone would be excavated and placed on the upland Landfill prior to
capping. The objective of this alternative is to minimize the impact to the aquatic
habitat and maximize long-term beach stability. The excavation backfill would
include a "design fill" component to help achieve water quality criteria in the
seeps by reducing the flux of contaminants leaching from landfill materials
(without altogether eliminating tidal exchange), and enhancing tidal dispersion
and seawater mixing. The backfill must also provide erosion protection and the
best possible habitat for marine organisms. The areal extent of the backfill would
be limited to the pre-excavation footprint of the landfill wastes.
Figure 11 shows the conceptual design of the excavation backfill used in the FS
for cost estimating purposes. It was assumed that the silty sand layer beneath the
intertidal debris would be excavated along with the debris itself, so that the
design fill material could be keyed into the underlying sandy silt. However,
design of the excavation and backfill requirements under this alternative,
including the need to excavate the silty sand layer, would be determined during
the remedial design phase.
Excavation of the intertidal landfill debris (volume estimated at 7,000 to 10,000
cubic yards) is expected to be difficult because of the presence of submarine
nets and the agglomerated nature of the debris. Special equipment may be
required, including hydraulic shears and torches, to facilitate debris excavation
and size reduction to allow placement/compaction in the upland landfill.
Protective measures such as a temporary dike would be constructed offshore to
prevent inundation at high tide and minimize the potential for drainage of landfill
runoff and suspended sediment into Clam Bay during excavation/construction
activities. The same land use restrictions, cap maintenance, restrictions on
shellfish harvesting, and sediment/tissue monitoring as in Alternative 2A would
apply. Sediment and tissue cleanup goals are predicted to be met 3 to 5 years
after remedial construction is completed.
Alternative 4AExcavation/Dredging, Limited Treatment, and Off-Site
Containment of All Landfill Debris, Soils, and Impacted Sediments. In this
alternative, all landfill debris (both intertidal and upland) would be excavated
and disposed of in an approved off-site landfill. During the RI/FS investigation,
roughly half of the landfill soil samples analyzed by TCLP failed for lead,
indicating that a large fraction of landfill materials may be characterized as
hazardous waste and, therefore, require special handling and treatment before
disposal.
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A very large volume of soil/debris would need to be excavated in this
alternative. As with the intertidal debris, upland debris is expected to be difficult
to excavate. The uplands excavation area would be restored by backfilling with
clean imported fill and revegetating. The intertidal excavation would be
backfilled with cobble and habitat material.
All Clam Bay sediments exceeding the cleanup levels would also be removed
and disposed of in an off-site landfill. No long-term monitoring would be
necessary for Alternative 4A.
It is estimated that Alternative 4A would require more than 2 years of field
implementation. By contrast, construction in Alternatives 2A and 3A could likely
be completed in a single construction season.
9.2 Alternatives for the Fire Training Area
Of the five alternatives evaluated in the FS for cleanup of the Fire Training Area,
the following three were considered in the Proposed Plan:
(18) No Action (FS Alternative B1);
(2B) Removal of All Dioxin-Contaminated Materials and In-Place Closure of
USTs (FS Alternative B3).
(3B) Removal of USTs and All Petroleum- and Dioxin-Contaminated Materials
(FS Alternative B5).
Descriptions of these three alternatives are presented below.
Alternative 1BNo Action. The No Action Alternative provides a baseline
against which to compare the other alternatives to evaluate their effectiveness.
Under this alternative, the USTs and all petroleum- and dioxin-contaminated
materials would be left in-place.
Alternative 2BRemoval of All Dioxin-Contaminated Materials and In-Place
Closure of USTs. In this alternative, debris contained in structures within the
main simulator complex with high concentrations of dioxin would be
transported for disposal in an approved RCRA hazardous waste landfill. Limited
areas of lower concentration dioxin-impacted soil outside the main simulators
and soil/debris located north of the simulators would be excavated and.
disposed of in an approved off-site landfill. Soils beneath the simulators would
be sampled and analyzed only if evidence of potential leakage through the
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simulator structures is identified. The structures would be demolished if needed
to complete removal of dioxin-impacted soils.
USTs in the Fire Training Area would be closed in-place following state UST
closure requirements. Piping systems and a small volume of TPH-impacted soils
excavated incidentally along with the piping, would be disposed of off site. To
address remaining soils with TPH concentrations greater than the Site cleanup
goal (200 ppm), there would also be restrictions and guidelines established for
activities which may disturb areas where these soils are left in-place.
Alternative 38Removal of USTs and All TPH- and Dioxin-Contaminated
Materials. Similar to Alternative 2B, this alternative includes excavation and
off-site disposal of all dioxin-contaminated soil and debris.
Instead of being closed in-place, USTs would be removed and disposed of off
site using conventional methods, fn addition, soils with TPH concentrations
greater than the Site cleanup goal would be excavated and biologically treated
(via landfarming) on Site to achieve the cleanup goal. Structures in the
immediate vicinity of the TPH-impacted soils (including the fire training stations
and the main simulator complex) would be demolished and removed from the
Site.
Implementation of Alternatives 28 and 3B could be completed in a single
construction season.
9.3 Alternatives for the Net Depot and Manchester State Park
"No Action" is the only alternative considered in the Proposed Plan for the Net
Depot and Manchester State Park areas of the Site, since these areas were not
identified as posing a risk to human health or the environment. [As discussed in
Section 8.4, the small portion of the landfill located on Manchester State Park
property will be addressed under the presumptive remedy (landfill capping)].
This alternative would result in the Net Depot and Manchester State Park areas
of the Site being left in their current condition.
10.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
Each of the remediation alternatives discussed above were evaluated against the
nine criteria specified by the NCP. The nine criteria include:
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* Two threshold criteria (overall protection of human health and the
environment, and compliance with ARARs), which must be met for an
~" alternative to be selected;
* Five balancing criteria (long-term effectiveness and permanence; reduction
of toxicity, mobility, or volume through treatment; short-term effectiveness;
implementability; and cost) for comparing and choosing a preferred
alternative, and
* Two modifying criteria (state acceptance and community acceptance) which
are factored into selection of the final cleanup action.
The following sections discuss and compare remediation alternatives relative to
the above criteria.
10.1 Evaluation of Landfill and Clam Bay Alternatives by Criteria
Overall Protection of Human Health and the Environment. Alternatives 2A,
3A, and 4A are protective of human health and the environment in terms of
reducing the risk of impacts from landfill contamination. Site risk reduction is
achieved in Alternatives 2A and 3A primarily by isolating impacted media from
human contact and the environment; however, Alternative 2A would result in
the loss of up to 0.9 acre of aquatic habitat. In Alternative 4A, it is achieved by
removing impacted media from the Site.
No Action (Alternative 1A) is not protective of human health or the
environment, the thus will not be considered further in this evaluation.
Compliance with ARARs. Alternatives 3A and 4A, which include removal of the
intertidal debris and excavation and removal of the entire landfill, respectively,
comply with all ARARs. There was considerable discussion within the
Manchester Work Croup on whether Alternatives 2A will achieve compliance
with all ARARs. One areas of uncertainty with Alternative 2A, raised bv the btate.
is the compliance of seep discharges at the landfill toe with surface water quality
criteria. Although preliminary evaluations of the expected performance of
Alternative 2A indicated that landfill capping and other hydraulic controls
included in this alternative would be more likely than not to achieve compliance
with surface water quality criteria at the seepage discharge point(s), this
condition could not be fully evaluated without detailed modeling, which was
beyond the scope of the FS.
In addition, the natural resource agencies in the Work Croup articulated their
position that habitat mitigation would be necessary under Alternative 2A to
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compensate for the loss of aquatic habitat function and area. Although
preliminary on-site mitigation options were identified which would partially
restore historical salt marsh habitat within this area and create more aquatic area
than would be lost, the resource agencies determined that other remedial
options such as Alternative 3A provided a practicable alternative to Alternative
2A which could obviate the need for any compensatory mitigation. Because the
Washington State Hydraulic Code Rules (Chapter 220-110 WAC) set forth
priorities to avoid or minimize aquatic habitat impacts wherever possible, and
allow consideration of compensatory mitigation only when impacts are
unavoidable, the resource agencies concluded that selection of Alternative 2A
may not be consistent with the state ARAR.
The Manchester Work Group was not able to reach an agreement on what
constituted the need for or an appropriate level of mitigation (e.g., ratio of
replacement habitat to lost or impacted habitat), in part because there is
currently no clear state or federal regulatory criteria for determining the need for
and level of mitigation for actions taken at CERCLA sites. Consequently,
Alternative 2A has a greater level of uncertainty with respect to ARAR
compliance, possibly with attendant cost and schedule impacts.
Long-Term Effectiveness and Permanence. The landfill cap and upgradient
hydraulic cutoff system included in Alternatives 2A and 3A prevent direct
contact exposure to upland landfill debris and effectively isolate the debris from
precipitation and groundwater infiltration. Provided these systems receive
periodic maintenance, they are expected to achieve long-term protection.
The landfill toe remedial components of Alternatives 2A and 3A both prevent
direct contact exposure to landfill debris in the intertidal zone. However,
Alternative 3A does provide some consolidation of the landfill waste by
excavating the landfill toe and placement in the upland portion of the landfill.
Alternative 3A is also designed to provide sufficient isolation of the debris from
intertidal flushing such that cleanup levels are achieved at the seeps. Both
Alternatives 2A and 3A appeared to be generally similar in terms of their
permanence, relative to susceptibility to beach erosion, though additional design
analyses would be necessary to fully evaluate this condition. Excavation and
placement of design fill under Alternative 3A would afford greater waste
isolation in a severe beach erosion event based on the greater thickness of clean
fill materials.
Alternative 4A provides long-term effectiveness and permanence at the Site by
removing all materials exceeding cleanup levels. A large portion of these
materials would be contained off site.
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Reduction of Toxicity, Mobility, or Volume through Treatment Alternatives 2A
and 3A do not include any treatment to reduce toxicity, mobility, or volume of
site contaminants. In Alternative 4A, all characteristic Dangerous Waste
materials from the landfill undergo on-site stabilization to reduce the potential
for metals leaching. The portion of the landfill debris which is likely to
characterize as Dangerous Waste is unknown.
Short-Term Effectiveness. Short-term effects associated with the construction/
implementation phase of a remedial alternative include impacts to the
environment to construction workers, and to the adjacent community (including
employees working at the EPA/Ecology Environmental Laboratory and the
NMFS Field Station). Capping of the upland landfill (Alternatives 2A and 3A) is
expected to have minimal short-term impacts. The existing landfill cover soil
provides protection against exposure to upland landfill debris. Dust control
measures during construction would be important to minimize short-term
inhalation risks and to minimize airborne particulate releases and associated
quality control problems within the environmental laboratories. The general
public does not have access to the Landfill Area. An alternative access route to
the EPA laboratory may need to be provided during construction activities.
The major potential impact associated with construction in the intertidal zone is
short-term degradation of the aquatic environment. The impacts of construction
activities in Alternative 2A, which include placement of protective armor over
the landfill toe, are expected to be relatively minor. Intertidal construction
activities in Alternative 3A are more extensive, including debris excavation at the
landfill toe. Short-term impacts associated with excavation of landfill debris in the
intertidal zone include disturbance of aquatic habitat during placement and
removal of a tidal dike and debris removal, and potential release of
contaminants associated with landfill debris to the environment. Measures taken
to minimize short-term impacts to the aquatic environment would include
working during low tides to the extent possible, and placement of a temporary
dike during debris excavation to prevent erosion of cut faces into Clam Bay.
Excavation of landfill debris in Alternatives 3A and 4A would subject
construction workers to significantly higher constituent concentrations
compared to Alternative 2A due to the increase level of waste excavation and
disposal. Exposure potential would be largest by far in Alternative 4A, where all
landfill debris would be excavated.
Implementability. The construction components of Alternative 2A require only
conventional methods and equipment, and are readily implemented. However,
the implementability of mitigation measures required with Alternative 2A are
uncertain, since the type and extent of mitigation have not been determined.
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Alternative 3A requires partial excavation of the landfill (the intertidal portion
only), and Alternative 4A requires complete excavation of all landfill debris.
Landfill debris is expected to be difficult to excavate because of submarine nets
and agglomerated wastes reported to be present. Size reduction of the
excavated debris may also be difficult using conventional methods. Field trials of
excavation and/or size reduction techniques may be required prior to remedial
design of an action which includes excavation of landfill debris.
The on-site treatment (stabilization), transportation, and disposal components of
Alternative 4A would all likely present major implementation hurdles based on
the large quantity of material involved. An estimated 140,000 tons of material
would be transported off the Site. Even assuming that only a small fraction of
excavated materials would require stabilization, the construction phase of
Alternative 4A would likely require several years to implement
Alternatives 2A through 4A involve dredge and fill activities in the Clam Bay
intertidal zone. These activities would require coordination with several
government agencies, leading to possible implementation difficulties and delays.
Construction in Alternatives 2A through 4A would impact the only access road
to the EPA/Ecology Environmental Laboratory. Provision must be made for
access to these facilities. The institutional controls required in Alternatives 2A
and 3A are considered easy to implement
Cost The estimated cost of each remediation alternative for the Landfill and
Clam Bay is shown below:
Present Worth
Initial of Annual Present Worth
Alternative Costs O&M Costs of Total Costs
1A $0 SO $0
2A $3,100,000 5370,000 $3,500,000
3A $4,600,000 $260,000 $4,900,000
4A $47,000,000 $0 $47,000,000
Notes:
(1) Present worth estimates assume an annual inflation rate of 2.2 percent. A
maximum project life of 30 years is assumed, in accordance with EPA
guidance. Estimates are in 1996 dollars.
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State Acceptance. The State of Washington has reviewed the Landfill and Clam
Bay alternatives, and has expressed a strong preference for Alternative 3 A which
involves excavation of the landfill toe from the intertidal zone. The state has also
indicated that armoring of the landfill toe under Alternative 2A would require
mitigation measures to offset the loss of aquatic habitat.
Public Acceptance. The public has had the opportunity to review and comment
on the range of alternatives considered for remediation of the Landfill and Clam
Bay. At the employee briefing on the preferred alternative, several concerns
were raised regarding implementation of the remedial action, including issues of
site access, employee health and safety, and disruption of laboratory functions.
As noted in the Responsiveness Summary (Attachment A), the on-site
laboratories will have opportunities to review and comment on draft versions of
the remedial design and construction documents, to assure that employee
concerns are addressed before construction activities begin.
The overall supportive public comments received during the comment period
for the Proposed Plan and at the public meeting have been interpreted as
acceptance of the proposed alternative.
10.2 Evaluation of Fire Training Area Alternatives by Criteria
Overall Protection of Human Health and the Environment Alternatives 2B and
38 are protective of human health and the environment in terms of reducing the
risks associated with dioxin-impacted soil and debris in the Fire Training Area.
The primary difference between the alternatives is the extent to which TPH-
impacted soils are cleaned up. These soils are excavated and treated on the Site
in Alternative 3B. However, since the TPH-impacted soils represent a limited Site
risk, this alternative is only slightly more protective than Alternative 2B.
No Action (Alternative 1B) is not protective of human health or the
environment, thus will not be considered further in this evaluation.
Compliance with ARARs. Alternatives 2B and 3B comply with all ARARs.
Long-Term Effectiveness and Permanence. Off-site disposal of dioxin-impacted
.soil and debris in Alternatives 2B and 3B permanently removes from the Site all
risks associated with those materials. However, containment is not normally
regarded as a permanent technology. Both Alternative 2B and 3B are similar in
terms of the reduction of Site risk. By leaving the TRH-impacted soils in-place,
Alternative 2B provides some potential for future exposure, although the
petroleum residual is largely non-leachable and poses only a minimal risk at the
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Site. Landfarming (Alternative 38) provides permanent reduction of TPH in soil
to below the cleanup goal.
Reduction of Toxicity, Mobility, or Volume through Treatment. As noted
above, landfarming of TPH-impacted soils in Alternative 3B reduces the toxicity
of these soils, whereas Alternative 28 leaves TPH-impacted soils untreated. PCB-
impacted petroleum product/sludge removed from the USTs would be disposed
of off the Site by placement in an approved landfill or incineration.
Short-Term Effectiveness. The greatest exposure risk to construction workers is
in the removal of the debris from inside the simulators, which is a component of
Alternatives 28 and 3B. Excavation of dioxin-contaminated surficial soil and
external debris presents less of an exposure risk, based on the lower
concentrations found in those materials. Exposure risks associated with UST
closure/removal and TPH-impacted soil excavation/bioremediation are relatively
minor. Construction worker exposure would be minimized through the use of
protective clothing, dust control, and respirators if required.
Alternatives 28 and 38 are not expected to have appreciable short-term impacts
on the environment or on the local community.
Implementability. The construction components of Alternatives 28 and 38
require only conventional methods and equipment, and are readily
implemented. Biological treatment of TPH-impacted soil via landfarming
(Alternative 36) has been demonstrated at many sites, and is readily
implemented. The institutional controls associated with the TPH-impacted soils
left in-place in Alternative 2B are considered easy to implement
Cost The estimated cost of each remediation alternative for the Fire Training
Area is shown below:
Present Worth
Initial of Annual Present Worth
Alternative Costs O&M Costs of Total Costs
IB SO SO SO
28 $740,000 $0 $740,000
38 $2,400,000 $0 $2,400.000
Notes:
(1) Present worth estimates assume an annual inflation rate of 2.2 percent. A
maximum project life of 30 years is assumed, in accordance with EPA
guidance. Estimates are in 1996 dollars.
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State Acceptance. The State of Washington has reviewed the Fire Training Area
affernatives and has expressed a preference for Alternative 2B as an appropriate
response action. The state has approved this document and the selected
remedy.
Public Acceptance. The public has had the opportunity to review and comment
on the range of alternatives considered for remediation of the Fire Training Area.
The overall supportive public comments received during the comment period
for the Proposed Plan and at the public meeting have been interpreted as
acceptance of the proposed alternative.
11.0 THE SELECTED REMEDY
The alternative selected for the remedial action at the Manchester Annex
Superfund Site is generally consistent with Alternative 3A for the Landfill and
Clam Bay sediments. Alternative 28 for the Fire Training Area, and No Action for
the Net Depot Area and Manchester State Park. This remedy is preferred
because it complies with all ARARs, provides long-term protection of human
health and the environment, and is consistent with the state preference, while
striking a balance between Site risk reduction and cost The remedial action, to
the extent practicable, will be carried out in a manner that is not likely to
jeopardize listed species or adversely affect critical habitat
The selected remedy, which will cost an estimated $5.4 million (present worth),
includes the following actions.
11.1 Excavation oflntertidal Debris and Placement of Design Fill
+ Landfill debris located in the intertidal zone of Clam Bay will be excavated to
the extent necessary to establish a stable shoreline protection system and to
allow placement of the design fill (described below). The goal is no net loss
of aquatic habitat. A temporary dike or other means will be used to prevent
erosion of cut faces into Clam Bay, and construction methods will be
selected during remedial design/remedial action to minimize disturbance of
the intertidal area adjacent to the excavation. The volume of intertidal debris
requiring excavation is estimated to be in the range of 7,000 to 10,000 cubic
yards.
* As described in Larson (1997), it is possible that low-density hunter-tisher-
gatherer deposits are on the former beach surface underlying the intertidal
debris. A Cultural Resources Management Plan will be prepared during
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remedial design which specifies monitoring procedures, personnel
_ qualifications, notification requirements, and treatment of cultural resources
if they are discovered during remedial construction.
* Excavated material will be placed, to the extent possible, on the upland
landfill area prior to capping. Based on the presence of submarine nets and
the agglomerated nature of the debris, some of the excavated material may
be too large or otherwise physically unsuitable for placement/compaction
on Site. If determined during remedial design to be cost-effective, techniques
such as shearing will be used to reduce the size of excavated debris so that
it can be effectively placed on the on-site landfill. Debris that is physically
unsuitable for placement on the landfill and not amenable to size reduction
will be tested for waste designation purposes and disposed of in an
appropriate off-site landfill.
* The shoreline protection system will be designed to achieve seep cleanup
levels (Table 15), provide the best possible habitat for marine organisms, and
maximize long-term beach stability. It will include a "design fill" component
to help achieve water quality criteria in the seeps by reducing the flux of
contaminants leaching from landfill materials (without altogether eliminating
tidal exchange), and enhancing tidal dispersion and seawater mixing. Details
of the shoreline protection system will be refined during final design.
* Seeps at the foot of the finished construction, if observed, will be monitored
until compliance with seep discharge cleanup levels is established.
Additional remedial measures will be implemented, as necessary, if seep
discharge cleanup levels are not achieved.
11.2 Placement of Thick Sand Cap over Silt Basin Sediments
+ A cap, consisting of clean sediments or similar material, will be placed in the
existing intertidal depression ("silt basin") flush with the surrounding
mudline, to isolate contaminated basin sediments from the intertidal
environment. Placement of the cap will be coordinated with windrow
placement (discussed below).
11.3 Placement of Thin Cap over Remaining Surficial Sediments Exceeding
Cleanup Levels
* A thin cap of clean sediment will be established over intertidal Clam Bay
sediment areas which exceed cleanup levels, which are the SQS. The cap
area is estimated at roughly 5 acres. Cap material will be placed in
windrows, designed to be spread out evenly over time by wind and wave
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forces. To the extent practicable, the gradation of the material used will be
matched with the existing native sediment grain size.
* Details of thin capping (including volume of clean sediment applied,
windrow design, etc.) will be determined during final design. The overall goal
is to reduce contaminant concentrations in surficial sediments sufficiently to
assure that sediment dwelling organisms, including harvestable shellfish
resources, are adequately protected to support unrestricted use of the cap
area within several years of completion of the remedial action.
* Clam Bay sediment and shellfish tissue will be monitored in intertidal areas
currently exceeding the PCS cleanup goal for sediments (40 ug/kg [dry])
until compliance with sediment and shellfish tissue cleanup goals is
established, or until the Washington State Department of Health and the
Suquamish Tribe determine that the shellfish are safe for subsistence-level
harvesting, whichever occurs first
11.4 Installation of Landfill Cap and Hydraulic Cutoff System
* Prior to cap construction, any solid waste located west of the utility corridor
which runs along the EPA/Manchester State Park property boundary will be
excavated and placed on the remaining upland landfill area. (Alternatively,
the utility corridor will be relocated to outside the areal extent of solid
waste.)
* After placement of debris excavated from the intertidal area and Manchester
State Park (or relocation of the utility corridor), the upland portion of the
landfill (approximately 5 to 6 acres) will be capped in accordance with the
State of Washington's Minimum Functional Standards (MFS) for solid waste
landfill closures. (Design requirements of an MFS cap include a low-
permeability cover liner with a 2 percent minimum slope, protective layers
above and below the cover liner, landfill gas controls, and close construction
quality control and inspection requirements.) The cap will be designed to be
consistent with the owner's long-term plans for the property, which may
include use of a portion of the landfill area as parking for a future laboratory
' expansion.
* A hydraulic cutoff system will be installed upgradient of the landfill area, to
capture groundwater and surface water approaching the upgradient edge of
the landfill cap, divert captured water around the landfill, and discharge it to
Clam Bay. The system will be designed such that it will not serve as a
conduit for seawater infiltration into the landfill during high tides.
HartCrowser Page 3)
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* Potential construction-related impacts to existing wetlands in the landfill
vicinity will be identified and addressed as part of final design.
+ After completion of upland construction, the area will be revegetated,
consistent with long-term O&M requirements and site development plans.
+ A post-closure plan for the landfill cap, hydraulic cutoff system, and shoreline
protection system, will be developed during remedial construction and
implemented following construction. The post-closure plan will address long-
term operation, monitoring, inspection, and maintenance requirements for
these systems.
11.5 Excavation/Disposal of Dioxin-Contaminated Debris and Soil
* Dioxin-contaminated debris (volume estimated at 200 cubic yards) will be
removed from the main simulator complex in the Fire Training Area and
disposed of in a RCRA hazardous waste landfill.
* After removal of debris, the floors of the simulators will be inspected for
cracks or other routes of potential leakage. If routes of potential leakage are
found, soils beneath the simulators will be sampled and analyzed for dioxins.
If dioxin concentrations above the cleanup level are detected, the
simulator(s) will be demolished, and the underlying contaminated soils
excavated.
* Near-surface soils adjacent to the main simulator complex, and the
soil/debris pile north of the main complex, will be sampled and analyzed for
dioxins. Soil and debris with concentrations above the cleanup level
(estimated at 200 to 300 cubic yards) will be excavated for off-site disposal.
* Excavated dioxin-contaminated debris and soil, and simulator demolition
debris (if applicable), will be tested for waste designation purposes and
disposed of in appropriate off-site landfills.
11.6 In-Place Closure ofUSTs
* The concrete USTs (five or more) remaining in the Fire Training Area will be
closed in-place following state UST closure requirements. Pumpable
materials will be removed from the USTs and associated piping, tested for
waste designation purposes, and treated/disposed of off Site in an
appropriate manner.
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UST piping systems, and TPH-impacted soil excavated incidentally along
__ with the piping, will be disposed of in an appropriate off-Site landfill. The
goal will be to remove all UST system piping. However, pipe sections which
are impractical to remove (due to existing utilities or other obstacles), will be
purged and abandoned in-place.
11.7 Institutional Controls
In conjunction with the landowners, the Corps will develop and put into place
the following institutional controls:
* A description of the activities or prohibitions required for continued
maintenance and protection of the remedial action, including the landfill
cap, shoreline protection system, and hydraulic cutoff system, will be
prepared during remedial design. These requirements will be subsequently
placed in the CSA files, the County Land Use Records, and all applicable
public files for the property, including locations at the site, EPA regional
office, and EPA headquarters. In addition, deed covenants prohibiting future
residential use of the property, and describing the maintenance and
protection requirements, will be prepared and submitted for EPA approval.
The deed covenants shall be executed upon any future transfer of the
property out of federal government ownership.
> A restriction on subsistence-level harvesting of shellfish until the Washington
State Department of Health and the Suquamish Tribe determine that the
shellfish are safe for subsistence-level harvesting. The Suquamish Tribe will
be responsible for prohibiting subsistence-level harvesting of shellfish.
* An institutional control plan, including deed covenants as necessary, will be
prepared and submitted for NMFS approval to address TPH-impacted soil
left in-place in the Fire Training Area. The institutional control plan shall
include the following (as appropriate):
Execution of a deed covenant prohibiting future residential use of the
property, and describing the presence of TPH-impacted soils, including
information on location/depth, concentrations, and health and saretv
concerns;
All contractors and employees working in future subsurface excavations
within and adjacent to the UST areas of the Site will be notified of the
requirement to utilize health and safety precautions normally applicable
to UST removals;
HartCrowser . Page 39
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Temporary storm water controls and other best management practices
- (BMPs) such as temporary soil covers and subsurface liners will be used
during future soil excavation activities in these areas to minimize
infiltration and runoff of soil materials;
Subsurface soil excavations within these areas will be observed by a
qualified environmental professional to determine if such soils contain
free product. If free product is encountered, off-Site landfill disposal of
these materials will be the prospective remedy. If free product is not
encountered, the soils will be allowed to be returned to the original
excavation, or very close to the original excavation in a substantially
similar environment; and
Future storm water runoff systems at the Site will be designed to divert
runoff away from the former UST areas.
NMFS will be responsible for ensuring long-term compliance with the
institutional control plan for the NOAA property. Compliance with this plan
will obviate the need for further sampling or remedial actions associated
with TPH-impacted soil left in-place in the Fire Training Area.
Each property owner will ensure that future construction will not compromise
the institutional controls that are put into place. The effectiveness of the
institutional controls will be evaluated as part of reviews to be conducted at
5-year intervals, at a minimum, or as required based on the performance
evaluation criteria of this remedy.
The Manchester Annex Work Group will continue to function during planning
and implementation of the selected remedy. Interested parties, such as Site
employees, will be encouraged to be involved in design and construction issues
through the Work Group.
12.0 STATUTORY DETERMINATIONS
The remedial action for implementation at the Manchester Annex Supertund
Site is consistent with CERCLA and, to the extent practicable, the NCR. The
selected remedy is protective of human health and the environment, attains all
ARARs, and is cost-effective.
Hart Crowser Page 40
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12.1 Protection of Human Health and the Environment
Trie selected remedial action is protective of human health and the environment
through a combination of on-Site containment/capping, beach stabilization, off-
Site disposal, and institutional controls. Excavating the intertidal landfill debris,
constructing a stable beach, capping the upland landfill, and installing a hydraulic
cutoff system upgradient of the landfill will isolate landfill wastes from human
contact and the environment, and reduce or eliminate future contaminant
discharges to Clam Bay. Capping of the "silt basin" and placement of a thin cap
over remaining impacted sediments, enhancing the natural recovery process,
will reduce surface sediment and shellfish tissue chemical concentrations to
levels protective of human health and the environment. Temporary restrictions
on subsistence-level harvesting of shellfish will ensure protection of public health
until the Washington State Department of Health and the Suquamish Tribe
determine that the shellfish are safe for subsistence-level harvesting.
Excavation and off-site disposal of dioxin-impacted debris and soil will address
the primary risk concerns in the Fire Training Area. Institutional controls
addressing TPH-impacted soil left in-place at the Site will provide protection of
human health and the environment from these materials.
12.2 Compliance with Applicable or Relevant and Appropriate Requirements
The selected remedy will comply with all chemical-, action-, and location-specific
applicable or relevant and appropriate requirements (ARARs). The ARARs are
presented below.
Landfill Area. Clam Bay, and Fire Training Area ARARs
+ The State of Washington Hazardous Waste Management Act (Chapter
70.105 RCW) establishes requirements for dangerous waste and extremely
hazardous waste, as codified in Chapter 173-303 WAC. This regulation is
applicable to wastes that are taken outside an existing area of
contamination. The regulation designates those solid wastes which are
dangerous or extremely hazardous to the public health and the
environment; provides surveillance and monitoring requirements for such
wastes until they are detoxified, reclaimed, neutralized, or disposed of safely;
and establishes monitoring requirements for dangerous and extremely
hazardous waste transfer, treatment, storage, and disposal facilities.
» The State of Washington Hazardous Waste Cleanup Model Toxics
Control Act (MTCA; Chapter 70.105D RCW) establishes requirements for
the identification, investigation, and cleanup of facilities where hazardous
HartCrowser
I-419M9
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substances have come to be located, as codified in Chapter 173-340 WAC
Soil, groundwater, and surface water cleanup standards established under
the MTCA, along with overall cancer risk and hazard index requirements, are
applicable for determining remediation areas and volumes and compliance
monitoring requirements within the Landfill Area, Clam Bay, and Fire
Training Area of the Site.
The State of Washington Sediment Management Standards (SMS; Chapter
173-204 WAC) establish chemical-specific sediment quality standards (SQS)
which are applicable within Clam Bay to control potential adverse effects on
biological resources. Sediments must meet the cleanup standards within ten
years after completion of the remedial action.
The State of Washington Surface Water Quality Standards (SWQS;
Chapter 1 73-201A WAC), as developed pursuant to the federal ambient
water quality criteria (40 CFR 131) are applicable chemical-specific standards
for determining cleanup requirements for surface water discharges, including
tidal seeps from the landfill area.
The Toxic Substances Control Act (TSCA) establishes storage and disposal
requirements for wastes containing PCBs greater than 50 ppm (40 CFR 761).
These requirements are applicable to wastes that are taken outside of an
existing area of contamination.
The State of Washington Clean Air Act (Chapter 70.94 RCW), including
Implementation of Regulations for Air Contaminant Sources (Chapter 1 73-
403 WAC), and Controls for New Sources of Toxic Air Pollutants (Chapter
173-460 WAC) are applicable standards for determining ambient
concentrations of toxic air contaminants allowed during remedial actions
conducted throughout the Site. In addition, requirements for control of
fugitive dusts and other air emissions during excavation and cleanup-related
activities, as codified in WAC 1 73-400-040, are also applicable to remedial
actions.
Sections 401 and 404(b)(1) of the Federal Clean Water Act (40 CFR 230)
and Section 10 of the Rivers and Harbors Act (33 CFR 320-330) protect
marine environments and prevent unacceptable adverse effects on shellfish
beds, fisheries, wildlife, and recreational areas during dredging activities.
These regulations are applicable to excavation, dredging, and till activities
conducted in the intertidal area of Clam Bay and in possible wetlands within
the upland landfill area.
HartCrowser Page 42
1-4191-19
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* The State of Washington Underground Storage Tank Regulations (Chapter
1 73-360 WAC) establish requirements for the permanent closure of USTs
~ (173-360-385 WAC) which are applicable to in-place closure of the concrete
USTs in the Fire Training Area.
The Kitsap County Shoreline Master Plan (WAC 173-19-2604), as
developed pursuant to the State of Washington Shoreline Management Act
(Chapter 90.58 RCW) covers fill, dredging, and other remedial activities
conducted in Clam Bay within 200 feet of the shoreline.
* State of Washington (WISHA) and Federal (OSHA) requirements are
applicable standards establishing safe operating procedures and
requirements for the conduct of all remedial actions at the Site. The state
regulations are codified in Chapter 296-62 (Part P) WAC
* The CERCLA Off-Site Disposal Rule, as set forth in an amendment to the
NCP, Procedures for Planning and Implementing Offsite Response Actions
(40 CFR 300.440), is applicable to off-site disposal actions included in the
selected remedy. In addition, RCRA establishes land disposal restrictions (40
CFR Part 268) that must be met before hazardous wastes can be land
disposed.
* The State of Washington Minimal Functional Standards (MFS) for Solid
Waste Handling (Chapter 173-304 WAC) are relevant and appropriate
standards for the design of landfill containment and long-term operations
and maintenance requirements within the landfill cap area.
> The State of Washington Hydraulic Code Rules (Chapter 220-110 WAC)
contains standards for removal and filling actions waterward of the ordinary
high water elevation.
* The Endangered Species Act (16USC 1531-1544) conserves threatened or
endangered species.
Other Criteria. Advisories, or Guidance To-Be-Considered (TBC)
» Executive Orders 11990 and 11988 (40 CFR 6, Appendix A), which are
intended to avoid adverse effects, minimize potential harm, and restore and
preserve natural and beneficial uses of wetlands and floodplains.
* Requirements and guidelines for evaluating dredged material, disposal site
management, disposal site monitoring, and data management established by
Puget Sound Dredge Disposal Analysis (PSDDA, 1988 and 1989).
Hart Crowser Page 43
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*_ Critical toxicity values (acceptable daily intake levels, carcinogenic potency
factor) and U.S. Food and Drug Administration action levels for
concentrations of mercury and PCBs in edible seafood tissue.
+ EPA Wetlands Action Plan (EPA, 1989) describing the National Wetland
Policy and primary goal of "no net loss."
+ Puget Sound Storm Water Management Program (pursuant to 40 CFR Parts
122-24, and RCW 90.48).
* Puget Sound Estuary Program Protocols, (1987) as amended, tor sample
collection, laboratory analysis, and QA/QC procedures.
12.3 Cost Effectiveness
The selected remedy is cost-effective because it is protective of human health
and the environment, achieves ARARs, and its effectiveness in meeting the
objectives of the selected remedy is proportional to its cost Cost-effectiveness
was also established in the presumptive remedy for military landfills. Specific risk
and cost balances achieved by the selected remedy include the following:
* On-site containment of landfill wastes is more cost-effective and affords the
same relative risk reduction as treatment and disposal of wastes in an off-site
landfill.
> Implementing effective source controls, including capping of Clam Bay
sediments, provides long-term protection at significantly lower cost than
sediment dredging and off-site disposal.
* Removing dioxin-impacted soil, which represents the majority of Site risk in
the Fire Training Area, and implementing institutional controls to address low
risk TPH-impacted soils left in-place, achieve an effective balance of risk
reduction and cost.
The selected remedial components are substantially more cost-effective than the
alternative components considered, while achieving the same substantive risk
reduction.
Hart Crowser Page 44
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12.4 Utilization of Permanent Solutions and Alternative Treatment Technologies
or Resource Recovery Technologies to the Maximum Extent Practicable
The Corps and EPA have determined that the selected remedy represents the
maximum extent to which permanent solutions and treatment technologies can
be used in a cost-effective manner for the Manchester Annex Superfund Site.
12.5 Preference for Treatment as Principal Element
The selected remedy uses no treatment technologies except possible
incineration of PCB-containing UST residue associated with the Fire Training
Area. Given the large volume and nature of the waste at the Site, containment,
as a presumptive remedy for the landfill, provides effective protection of human
health and the environment at a considerably lower cost than treatment to
achieve the same degree of risk reduction.
13.0 DOCUMENTATION OF NO SIGNIFICANT CHANGES
The Corps and EPA released the Manchester Annex Superfund Site Proposed
Plan (preferred remedial alternative) for public comment on April 1, 1997. The
preferred alternative presented in the proposed plan is the same as the selected
alternative presented in this Record of Decision. The Corps and EPA reviewed all
written and verbal comments submitted during the public comment period.
Upon review of those comments, it was determined that no significant changes
to the remedy, as it was originally identified in the proposed plan, were
necessary.
14.0 REFERENCES
(A)
Corps, 1993. US Army Corps of Engineers - Seattle District. Preliminary
Assessment: Manchester Field Station, Manchester, Washington. For National
Oceanic & Atmospheric Administration, October 1993.
Corps, 1995. US Army Corps of Engineers - Seattle District. Chemical Quality
Assessment Report. Sediment Sampling Results from NMFS and Corps Sampling
in February and March 1994 at Manchester Annex, Manchester, Washington.
Corps, 1997. US Army Corps of Engineers - Seattle District. Proposed Plan for
Site Cleanup, Manchester Annex Superfund Site, Manchester, Washington.
March 1997.
HartCrowser Page 45
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Dollarhide, Joan S., 1992. Oral Reference Doses and Oral Slope Factors for JP-4,
JP-5, Diesel Fuel, and Gasoline. Memorandum to Carol Sweendy, U.S. EPA,
Region 10, March 24, 1992.
Ecology and Environment, Inc., 1987. Preliminary Assessment of EPA's Region X
Manchester Laboratory. Prepared for EPA, April 30, 1987.
Ecology and Environment, Inc., 1988. Site Inspection Report, USEPA Manchester
Laboratory, Manchester, Washington, TDD F10-8710-01. For the US EPA.
EPA, 1985. U.S. Environmental Protection Agency, Drinking Water Criteria
Document for Copper, EPA 600-X-84-190-1, March 1985.
EPA, 1989. Update of Toxicity Equivalency Factors (TEFs) for Estimating Risks
Associated with Exposures to Mixtures of Chlorinated Dibenzo-/oDioxins and
Dibenzofurans (CDD and CDFs). Risk Assessment Forum, February 1989.
EPA, 1992. Site Investigation of an Old U.S. Navy Dump Site Near Manchester,
Washington, September 1992.
EPA, 1993. Provisional Guidance for Quantitative Risk Assessment of Polycyclic
Aromatic Hydrocarbons, EPA/600/R-93/089, July 1993.
EPA, 1995a. Integrated Risk Information System. Office of Research and
Development, Environmental Criteria and Assessment Office, October 1995
accession.
EPA, 1995b. Health Effects Assessment Summary Tables. Annual FY 1995. EPA
Office of Solid Waste and Emergency Response Report No. OS-230.
Hart Crowser, 1994a. Project Management Plan, Manchester Annex Site,
Remedial Investigation/Feasibility Study, Site No. F102A011900, Manchester,
Washington. October 19, 1994.
Hart Crowser, 1994b. Manchester Fisheries Laboratory, Dioxin and Furan
Sampling, Manchester, Washington. Prepared for U.S. Army Corps of Engineers.
April 8, 1994.
Hart Crowser, 1995a. Draft Site Characterization Technical Memorandum,
Manchester Annex Remedial Investigation/Feasibility Study (SCTM), Site No.
F10WA11900, Manchester, Washington. Volumes I, II, and III. July 10, 1995.
Hart Crowser Page 46
1-4191-19
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HartCrowser, 19-95b. Addendum No. 1 to the Project Management Plan,
Manchester Annex Site Remedial Investigation/Feasibility Study, Site
No. F10WA011900, Manchester, Washington. September 1, 1995.
Hart Crowser, 1995c. Addendum No. 1 to the SCTM, Draft Site
Characterization Technical Memorandum, Manchester Annex Remedial
Investigation/Feasibility Study, Site No. F10WA11900, Manchester, Washington.
November 6, 1995.
Hart Crowser, 1995d. Addendum No. 2 to the Project Management Plan,
Manchester Annex Site Remedial Investigation/Feasibility Study, Site
No. F10WA011900, Manchester, Washington. November 22, 1995.
Hart Crowser, 1995e. Evaluation of Early Remedial Action Options Considered
and Decision of Implementation, Manchester Annex Remedial
Investigation/Feasibility Study, Site F10WA011900. October 27, 1995.
Hart Crowser, 1996. Final Remedial Investigation/Feasibility Study, Manchester
Annex Superfund Site, Manchester, Washington. December 1996.
Larson, 1997. Larson Anthropological/Archaeological Services. Cultural
Resource Reconnaissance of the EPA's Manchester Laboratory Facility -
Manchester Annex Superfund Landfill Site, Kitsap County, Clam Bay,
Washington. January 14, 1997.
Oak Ridge National Laboratory, 1994. Manual for PC-Database Screening
Benchmarks for Ecological Risk Assessment. ORNL/TM-12898. Oak Ridge
National Laboratory, Oak Ridge, Tennessee. December 1994.
Smith, R.L., 1995. Risk-Based Concentration Table, January-June 1995. U.S.
Environmental Protection Agency, Region III, Philadelphia, Pennsylvania. March
7, 1995.
Suter, II, C.W., and J.B. Mabrey, 1994. Toxicological Benchmarks for Screening
Potential Contaminants of Concern for Effects on Aquatic Biota. Prepared by
Environmental Sciences Division, Oak Ridge National Laboratory, July 1994.
-------
Table 1 - Listing of Chemicals of Potential Concern, Manchester Annex Site
Metals
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Miscellaneous Inorganics
Asbestos
Cyanide
Volatile Organic Compunds
Vinyl chloride
Benzene
Polynudear Aromatic Hydrocarbons (PAHs)
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Dibenzo(a,h)anthracene
Fluoranthene
lndeno( 1,2,3
-------
If
v£ *
T n
Table 2 Summary of Soil Quality Data for Landfill Area
Sheet 1 of 2
Cu
00
>£>
Inorganics in mg/kg
Cyanide
Total Metals in mg/kg
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Volatile; in Mg/kg
Benzene
Vinyl Chloride
Semivolatiles in ug/kg
2,4-Dimethylphenol
Benzo(a)Anlhracene
Benzo(a)Pyrene
Benzo(b)Fluoranlhene
Dibenzo(a,h)Anlhracene
Oi-N Bulylphthalale
riuoranlhene
lndfno(l,2, 1 -t,d)l'yri!iur
lul.ild'Atlb
Detection
Frequency
0/5
15/25
31/31
24/31
25/31
31/31
31/31
30/31
20/20
20/31
31/31
3/31
19/31
0/25
20/20
31/31
5/6
2/6
0/15
4/15
4/15
4/15
2/15
4/15
7/15
I/I 5
6/15
Maximum
Detection
ND
415 )
52.3
2.9
22800
690 N
23400
56000
1500 |
3.7
926 N
0.85 NE
67620
ND
590
23800
8
280
ND
2800
2600 )
5300 JX
930 J
150 .
8600
2100 |
21430
Human
Screening
Level
1600
31
7.3
0.61
2
100
2900
250
1100
7
1600
390
240
5.6
550
23000
500
2
1600000
880
88
880
88
100000
68000
880
1000
Health
Exceedence
Frequency ( 1 )
0/5
9/25
19/31
5/31
21/31
12/31
5/31
16/31
1/20
0/31
0/31
0/31
1/31
0/24
1/20
1/31
0/6
2/6
0/15
1/14
2/5
1/14
2/5
0/15
0/15
1/14
4/7
Plant
Screening
Level
5
10
10
2
48
50
50
0.1
48
1
2
1
85
40000
570
1500
71
and Wildlife
Exceedence
Frequency ( 1 )
14/25
16/31
0/30
21/31
16/31
23/31
21/31
12/29
17/31
0/14
15/26
0/15
25/31
0/6
0/6
1/14
1/6
-------
- ?
r o
-a
EU
00
n>
Ul
o
Table 2 - Summary of Soil Quality Data for Landfill Area
Sheet 2 of 2
-
Pesticide/PCBs in MgAg
4,4'-DDD
4,4'DDE
4.4J-PDT
Alclrin
Total PCBs
Dioxins in ng/kg
2378-TCDD
12378PeCDD
123478HxCDD
123678MxCDD
123789HxCDD
1234678-HpCDD
OCDD
2378-TCDF
12378HeCDF
23478PeCDF
123478-HxCDF
123678HxCDF
1 23789 HxCDF
234678-UxCDF
1 234678 llpCDF
1 234789 HpCDF
OCDF
2378-TCDD Equivalents
Total Petroleum Hydrocarbons in mg/kg
Diesel
Oil
Detection
Frequency
3/5
2/5
2/5
0/5
19/27
3/4
3/4
3/4
4/4
4/4
4/4
4/4
4/4
4/4
4/4
4/4
4/4
3/4
4/4
4/4
3/4
3/4
4/4
5/11
7/11
Maximum
Detection
10 J
160 |
5.9 |
ND
6900
110 j
241
321
553
922
2140
4900
1440 NC
1410
1640
3270
939
83.6 J
1190
4360
228
922
2100
280
2300
Human
Screening
Level
2700
1900
1000
38
83
4
8
40
40
40
400
4000
40
80
80
40
40
40
40
400
400
4000
200
200
Health
Exceedence
Frequency (1)
0/5
0/5
0/5
0/5
18/22
3/4
3/4
3/4
3/4
3/4
3/4
2/4
3/4
3/4
3/4
3/4
3/4
1/4
3/4
3/4
0/4
0/4
1/11
5/11
Plant and Wildlife
Screening Exceedence
Level Frequency ( 1 )
0.5 2/3
0.5 2/2
0.5 2/2
670 0/5
180 12/26
(I) Undetected sample results with quanlitalion limits greater than screening levels were excluded from exceedence frequency calculat
II'JI I'VKOOKuviii-d »li Tuble 2
-------
Table 3 - Summary of Soil Quality Data for Fire Training Area
Sheet 1 of 2
Inorganics in mg/kg
Cyanide
Total Metals in mg/kg
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Volatile* in Mg/kg
Benzene
Vinyl Chloride
Semivolatiles in ug/kg
2,4-Dimethylphenol
Beiuo(a)Anlhracene
Benzo(a)Pyrene
Benzo(b)Fluoranthene
Dibenzo(a,h)Anthracene
Di-N-Bulylphlhalate
riuoranlhene
lndeno( 1 ,2,3-c,d)l'yrene
Tol.il c PAI Is
Detection
Frequency
0/9
0/9
9/9
1/9
4/9
9/9
9/9
5/8
6/9
9/9
0/9
0/9
4/9
9/9
3/14
0/10
0/9
2/9
2/9
3/9
0/9
0/9
2/9
1/9
4/9
Maximum
Detection
ND
ND
12.6
0.55
1.2
21.5 J
69.5
113
' 0.14
29
ND
ND
0.27
253
72 )
ND
ND
210
240
690 X
ND
ND
350
400
2529
Human
Screening
Level
1600
31
7.3
0.61
2
100
2900
250
7
1600
390
240
5.6
23000
500
2
1600000
880
88
880
88
100000
68000
880
1000
Health
Exceedence
Frequency ( 1 )
0/9
0/9
1/9
0/9
0/9
0/9
0/9
0/8
0/9
0/9
0/9
0/9
0/9
0/9
0/14
0/6
0/9
0/9
1/9
0/9
0/9
0/9
0/9
0/9
1/9
Plant
Screening
Level
5
10
10
2
48
50
50
0.1
48
1
2
1
85
40000
570
1500
71
and Wildlife
Exceedence
Frequency ( 1 )
0/9
1/9
0/9
0/9
0/9
2/9
1/8
1/9
0/9
0/0
0/9
0/9
1/9
0/14
0/10
0/9
0/5
OQ
n
Ol
-------
Table 3 - Summary of Soil Quality Data for Fire Training Area
Sheet 2 of 2
Pesticide/PCBs in MgAg
4,4' DDD
4,4' DDL
4,4'-DDT
Aldrin
Total PCBs
Dioxins in ng/kg
2378TCDD
12378PeCDD
1 23478 HxCDD
123678 HxCDD
123789 HxCDD
1 234678 HpCDD
OCDD
2378-TCDF
12378PeCDF
23478-PeCDF
123478 HxCDF
123678 HxCDF
123 789 HxCDF
234678HxCDF
1234678-HpCDF
1234789-HpCDF
OCDF
23 78 TCDD Equivalents
Tula! Petroleum Hydrocarbons in
Diesel
Gasoline
Oil
Detection
Frequency
0/9
0/9
0/9
0/9
2/9
2/30
6/30
7/30
9/30
9/30
29/30
30/30
8/30
2/30
6/30
15/30
5/30
1/30
14/30
22/30
8/30
21/30
30/30
mgAg
23/77
2/9
20/77
Maximum
Detection
ND
ND
ND
ND
580
274
2590
4070
28100
23000 J
1260000 D
5820000 )D
840
266
505
5060 E
444
240
808
20600
1510
31900
26000
15000
480
7700
Human
Screening
Level
2700
1900
1000
38
83
4
8
40
40
40
400
4000
40
80
80
40
40
40
40
400
400
4000
200
100
200
Health
Exceedence
Frequency ( 1 )
0/9
0/9
0/9
0/9
1/6
2/5
6/18
5/23
8/24
7/23
15/30
14/30
5/22
2/21
4/22
9/23
3/21
1/20
4/22
5/30
2/30
3/30
13/77
1/9
18/77
Plant and Wildlife
Screening Exceedence
Level Frequency ( 1 )
0.5 0/0
0.5 0/0
0.5 0/0
670 0/9
180 1/9
oo
Ul
I J
(I) Uiulftf<.lcd b.miple results with (|ii.iniilalion limits greater than screening levels were excluded from exceedence frequency calculations.
I I'll I»/!<()l)Ki'MM-d »li
-------
Table 4 - Summary of Soil Quality Data for Net Depot Area
Sheet 1 of 2
Inorganics in mg/kg
Cyanide
Total Metals in mg/kg
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc:
Volatiles in pg/kg
Benzene
Vinyl Chloride
Semivolatiles in MgAs
2,4-Dimelhylphenol
Benzo(a)Anthracene
Benzo(a)Pyrene
lienzo(l>)l:kioranlhene
l)iben/o(a,h)Anlhracene
Di-N-Bulylphth.il.ite
Huoranlhcne
liuleno( l,2,3-c,d)fjyrene
Tol.ilcl'Alls
Detection
Frequency
2/3
0/3
6/6
6/6
5/6
6/6
6/6
6/6
3/3
5/6
6/6
0/6
0/6
0/6
3/3
6/6
0/3
0/3
0/6
2/6
2/6
2/6
0/6
1/6
2/6
2/6
2/6
Maximum
Detection
1
ND
8.4
0.65
4.7
37
71
72
283 j
0.31
19.5
ND
ND
ND
71
409
ND
ND
ND
170
140
410 X
ND
11 J
270
100
1437
Human Health
Screening Exceedence
Level Frequency ( 1 )
1600
31
7.3
0.61
2
100
2900
250
1100
7
1600
390
240
5.6
550
23000
500
2
1600000
880
88
880
88
100000
68000
880
1000
0/3
0/3
1/6
1/6
3/6
0/6
0/6
0/6
0/3
0/6
0/6
0/6
0/6
0/6
0/3
0/6
0/3
0/3
0/6
0/6
1/3
0/6
0/3
0/6
0/6
0/6
1/3
Plant and
Screening
Level
5
10
10
2
48
50
50
0.1
48
1
2
1
85
40000
570
1500
71
Wildlife
Exceedence
Frequency ( 1 )
0/2
0/6
0/6
3/6
0/6
1/6
2/6
1/6
0/6
0/3
0/6
0/3
5/6
0/3
0/3
0/6
0/3
-------
Table 4 - Summary of Soil Quality Data for Net Depot Area
Sheet 2 of 2
- n
.« Q
Cu
OQ
ft
Pesticide/PCBs in MgAg
4,4'-DDD
4,4' DDE
4,4'DDT
/.Iclrin
Total PCBs
Dioxins in ng/kg
2378TCDD
12378PeCDD
123478 HxCDD
123678 HxCDD
» 23 789 HxCDD
1 234678 HpC.DD
OCDI3
2378TCDI
l2378PeCDI
23478 I'cCDI
123478 HxCDF
123678 HxCDF
123 789 HxCDF
234678 HxCDF
1234678-HpCDF
1234789-HpCDF
OCDF
2378-TCDD Equivalents
Total Petroleum Hydrocarbons in mg/kg
Diesel
Oil
Detection
Frequency
0/3
0/3
0/3
0/3
2/3
1/1
1/1
1/1
1/1
1/1
1/1
1/1
I/I
0/1
1/1
0/1
1/1
0/1
1/1
1/1
'/I
1/1
1/1
2/3
2/3
Maximum
Detection
ND
ND
ND
ND
131
0.67
2.1
2.05
11.4
6.6
136
1620
8.69 NC
ND
4.31 J
ND
2.79 J
ND
5.3 )
53 J
2.38
173
11.26
47
350
Human Health
Screening Exceedence
Level Frequency ( 1 )
2700
1900
1000
38
83
4
8
40
40
40
400
4000
40
80
80
40
40
40
40
400
400
4000
200
200
0/3
0/3
0/3
0/3
1/2
0/1
o/i
0/1
0/1
0/1
o/i
0/1
o/i
0/1
0/1
0/1
0/1
0/1
0/1
o/i
o/i
0/1
0/3
2/3
Plant and Wildlife
Screening Exceedence
Level Frequency ( 1 )
0.5 0/0
0.5 0/0
0.5 0/0
670 0/3
180 0/3
(I) Undetected sample results with quanlitdtioM limits greater than screening levels were excluded from exceedence frequency calculations.
mi IM/KOI>Kevisfil xK lablr -I
-------
Table 5 - Summary of Groundwater Quality Data for Landfill Area (Surficial Fill Unit)
Detection Maximum
Frequency Detection
Total Metals in ug/L
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Observed Metals in ug/L
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Volatiles in ug/L
Benzene
Vinyl Chloride
Pesticide/PCBs in ug/L
PCB-1254
PCB-1260
Total PCBs
9/9
6/9
1/6
5/9
7/9
8/9
7/9
3/3
3/9
9/9
0/3
7/9
2/6
9/9
13/13
4/13
0/10
3/13
6/13
10/13
6/13
3/3
0/13
9/13
0/3
4/13
1/10
11/13
3/3
0/3
0/3
0/3
0/3
125
109
4.2
111
419
3130
2280
2710
1.6
716
ND
28.6
1.9
24100
33.3
14.8 J
ND
13.1
5.6
179
7.2
2010
ND
252 J
ND
1.6
1
5740
22
ND
ND
ND
ND
Seep Discharge
Screening Exceedence
Level ( 2 ) Frequency ( 1 )
36
50
0.025
71
1.2
36
8
50
10.6
5.8
0.025
7.9
71
1.2
77
700
0.03
0.03
0.03
2/9
2/9
3/3
0/3
4/9
0/13
1/13
0/13
4/13
1/13
0/0
6/13
0/3
1/13
6/13
0/3
0/0
0/0
0/0
Total Petroleum Hydrocarbons in mg/L
Diesel
Gasoline
Oil
8/12
3/3
0/12
1.1
1.3
ND
1
1
1
1/12
1/3
0/12
(1) Undetected sample results with quantitation limits greater than screening levels were excluded from
exceedence frequency calculations.
(2) Seep discharge screening level based on protection of marine aquatic life.
419119/ROD-Revised.xls - Table 5
Hart Oowser
MI91-19
Page 55
-------
Table 6 Summary of Groundwater Quality Data for Outwash Channel Aquifer
Sheet 1 of 3
Detection Maximum
Frequency Detection
Inorganics in ug/l
Cyiinide
Total Metals in ug/l
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Dissolved Metals in ug/l
Aiilmiony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
0/5
1/5
4/5
0/5
0/5
4/5
5/5
4/5
0/5
4/5
1/5
2/5
0/5
2/5
0/5
4/5
0/5
0/5
2/5
5/5
3/5
0/5
4/5
V5
0/5
0/5
0/5
ND
1.2
14.5
ND
ND
40.2
39
8.1
ND
37.8
91.1 )
0.51
ND
83.7
ND
14.5
ND
ND
12.9
13.6
1.2
ND
21.2
55.9 J
ND
ND
ND
Drinking Water
Screening Exceedence
Level Frequency ( 1 ]
200
6
5
0.016
5
80
590
5
2
100
50
80
1.1
4800
6
5
0.016
5
80
590
5
2
100
50
80
1.1
4800
0/5
0/5
4/5
0/0
0/5
0/5
0/5
1/5
0/5
0/5
1/5
0/5
0/5
0/5
0/5
4/5
0/0
0/5
0/5
0/5
0/5
0/5
0/5
1/5
0/5
0/5
0/5
Seep Discharge
Screening Exceedence
Level ( 2 ) Frequency ( 1 )
1 0/5
36 0/5
50 0/5
0.025 0/0
71 1/5
8 0/5
10.6 1/5
5.8 0/5
7.9 2/5
1.2 0/5
77 0/5
-------
Table 6 Summary of Groundwater Quality Data for Outwash Channel Aquifer
Sheet 2 of 3
Detection Maximum
Frequency Detection
Volatile; in ug/L
Benzene
Vinyl Chloride
Semivolatiles in pg/L
2,4-Dimelliylplienol
Benzo(a)Anthracene
Benzo(a)Pyrene
Benzo(b)Fluoranthene
Dibenzo(a,h)Anlhracene
Di N Bulylphlhalate
Fluoranlhene
lndcno( 1 ,2,3-c,d)Pyrene
Tol,il CPAHs
Peslicide/PCBs in pg/l
4.4- ODD
4.4' DPI
4,4' OUT
Aldrin
PCB-1254
PCIM260
Tola! PCBs
Oioxins in ng/L
2378-TCDD
12378PeCDD
1 23478 HxCDD
123678-HxCDD
123789-HxCDD
1234678 MpCDD
OCDI3
2378-TCDF
IJJ7HPK Dl
0/10
0/10
0/5
0/9
0/9
0/9
0/9
0/5
0/9
1/9
1/9
0/5
0/5
0/5
0/5
0/5
0/5
0/5
0/9
0/9
0/9
0/9
0/9
5/9
G/9
0/'j
0/<)
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.01 J
0.1265
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.029 )
151
ND
ND
Drinking Water Seep Discharge
Screening Exceedence Screening Exceedence
Level Frequency ( 1 ) Level (2) Frequency ( 1 )
0.36
0.019
320
0.092
0.0092
0.092
0.0092
1600
640
0.092
0.1
0.28
0.2
0.2
0.004
0.0087
0.0087
0.0087
0.0004
0.0008
0.004
0.004
0.004
0.04
0.4
0.004
0.008
0/0
0/0
0/5
0/4
0/0
0/4
0/0
0/5
0/9
0/4
1/1
0/5
0/5
0/5
0/5
0/0
0/0
0/0
0/0
0/0
0/3
0/3
0/3
0/5
1/6
0/5
0/5
700
300
300
300
300
300
300
0.001
0.001
0.001
0.0019
0.03
0.03
0.03
9E-06
1.7E-05
8.6E-05
8.6E-05
8.6E-05
0.00086
0.00864
8.6EO5
0.00017
0/10
0/9
0/9
0/9
0/9
0/9
0/9
0/0
0/0
0/0
0/0
0/0
0/0
0/0
0/0
0/0
0/0
0/0
0/0
5/5
6/6
0/0
0/0
-------
Table 6 - Summary of Groundwater Quality Data for Out wash Channel Aquifer
Sheet 3 of 3
Detection Maximum
Frequency Detection
23478-PeCDF
Oioxins in ng/L
1 23478 HxCDF
1 23678 HxCDF
123789 HxCDF
2 3 46 78 HxCDF
1 234678 HpCDF
1234789 HpCDF
OCDF
2 3 78 TCDD Equivalents
Total Petroleum Hydrocarbons in nig/L
Diesel
Oil
0/9
1/9
1/9
0/9
3/9
1/9
0/9
2/9
6/6
5/15
0/15
ND
0.004 j
0.003 )
ND
3.6
0.006 J
ND
0.012 J
0.36
0.59
ND
Drinking Water Seep Discharge
Screening Exceedence Screening Exceedence
Level Frequency ( 1 ) Level (2) Frequency ( 1 )
0.008
0.004
0.004
0.004
0.004
0.04
0.04
0.4
1
1
0/9
0/4
0/5
0/3 .
2/6
0/5
0/5
0/5
0/15
0/15
1.7EO5
8.6E-05
8.6E-05
8.6E-05
8.6E-05
0.00086
0.00086
0.00864
1
1
0/0
1/1
1/1
0/0
3/3
1/1
0/0
1/5
0/15
0/15
(I) Undetected sample results will) qu.inlilalion limits greater than screening levels were excluded from exceedence frequency calculations.
(2) Seep discharge screening level based on protection of marine aquatic life.
419119/ROD Revised xls - Table 6
-------
Table 7 - Summary of-Seep Quality Data for Landfill Area
Sheet 1 of 2
Inorganics in pg/L
Cyanide
Total Metals in pg/L
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Dissolved Metals in pg/L
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Volatile; in pg/L
Benzene
Vinyl Chloride
Detection
Frequency
1/2
12/16
0/16
0/12
8/16
11/16
16/16
14/16
4/4
1/16
8/12
1/7
10/16
4/12
3/4
15/16
12/12
0/12
0/8
7/12
11/12
12/12
3/12
2/12
8/8
V3
7/12
5/8
9/12
0/2
0/2
Maximum
Detection
5
20.3
N/A
N/A
4.4 J
7.3
354
56.3
230
0.13 P
46.7
51.8
2.1
6.6 J
42 P
240
17.7
N/A
N/A
4.2 J
4.1
21.3
1
0.59
47.3
51.8 |
0.78 J
3.6
232
N/A
N/A
Seep Discharge
Screening Exceedence
Level (2) Frequency ( 1 )
1
36
50
0.025
71
8
10.6
5.8
7.9
1.2
77
1/1
0/16
0/16
1/1
0/7
0/12
8/12
0/12
6/8
0/12
3/12 .
Hart Ccowser
H191-I9
Page 59
-------
Table 7 - Summary of Seep Quality Data for Landfill Area
Sheet 2 of 2
Detection
Frequency
Semivolatiles in ug/L
2,4-Dimethylphenol 0/2
Benzo(a)Anthracene 0/2
Benzo(a)Pyrene 0/2
Benzo(b)Fluoranthene 0/2
Dibenzo(a,h)Anthracene 0/2
Di-N-Butylphthalate 0/2
Fluoranthene 0/2
lndeno(1,2,3<,d)Pyrene 0/2
Total CPAHs 0/2
Pesticide/PCBs in Hg/L
4,4'-DDD 0/7
4,4'-DDE 0/7
4,4'-DDT 0/7
Aldrin 0/7
PCB-1254 3/17
PCB-1260 1/17
Total PCBs 3/1 7 .
Total Petroleum Hydrocarbons in mg/L
Diesel 0/13
Gasoline 0/1
Oil 0/12
Seep Discharge
Maximum Screening Exceedence
Detection Level (2) Frequency (1)
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
0.12
0.11
0.12
N/A
N/A
N/A
300
300
300
300
300
300
0.001
0.001
0.001
0.0019
0.03
0.03
0.03
1
1
1
0/2
0/2
0/2
0/2
0/2
0/2
0/0
0/0
0/0
0/0
3/3
1/1
3/3
0/13
0/1
0/12
(1) Undetected sample results with quantitation limits greater than screening levels were excluded from
exceedence frequency calculations.
(2) Seep discharge screening level based on protection of marine aquatic life.
419119/ROD-Revised.xls - Table 7
Hart Crowser
J-4I91-I9
Page 60
-------
Table 8 Summary otSurface Water and Seep Quality Data for Fire Training Area
Detection
Frequency
Volatile; in ug/L
Benzene
Vinyl Chloride
Pesticide/PCBs in ug/l
PCB-1254
PCB-1260
Total PCBs
Total Petroleum Hydrocarbons in
Diesel (3)
Gasoline
Oil
0/1
0/1
0/2
0/2
0/2
mg/L
1/9
0/3
0/7
Maximum
Detection
ND
ND
ND
ND
ND
5.2 D
ND
ND
Seep Discharge
Screening Exceedence
Level (2) Frequency ( 1 )
0.03
0.03
0.03
1
1
1
0/0
0/0
0/0
1/9
0/3
0/7
(1) Undetected sample results with quantitation limits greater than screening levels were excluded from
exceedence frequency calculations.
(2) Seep discharge screening level based on protection of marine aquatic life.
(3) The only exceedence was a detection of diesel associated with discharge from a drain pipe to a pond
in the southern portion of the Fire Training Area.
419119/ROD-Revised.xls Table 8
Hart Crowser
M19M9
Page 61
-------
Table 9 - Summary of Surface Water and Seep Quality Data for Net Depot Area
Sheet 1 of
Inorganics in pg/L
Cyanide
Total Metals in pg/L
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Dissolved Metals in pg/L
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Volatile; in pg/L
Benzene
Vinyl Chloride
Semivola tiles in pg/L
2,4-Dimethylphenol
Benzo(a)Anthracene
Benzo(a)Pyrene
Benzo(b)Fluoranthene
Dibenzo(a,h (Anthracene
Di-N-Butylphthalate
Detection
Frequency
2/4
4/4
0/4
0/4
1/4
4/4
4/4
2/4
0/4
4/4
0/4
2/4
2/4
3/4
4/4
0/4
0/4
1/4
3/4
4/4
0/4
0/4
4/4
0/4
2/4
3/4
3/4
0/4
0/4
0/4
0/4
0/4
0/4
0/4
0/4
Maximum
Detection
10.8
5.2 J
ND
ND
3.3 J
8.4
8.4 J
1.1
ND
10.9 J
ND
1.3 J
10.9 J
70.4
3-6 J
ND
ND
3.4 J
3.3 J
30.6
ND
ND
11.2 J
ND
0.67
7 J
53.6
ND
ND
ND
ND
ND
ND
ND
ND
Seep Discharge
Screening Exceedence
Level (2) Frequency (1)
1
36
50
0.025
71
8
10.6
5.8
7.9
1.2
77
300
300
300
300
2/2
0/4
0/4
0/0
0/4
0/4
1/4
0/4
1/4
0/4
0/4
0/4
0/4
0/4
0/4
Hjrt Crowjgr
I-419M9
Page 62
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Table 9 - Summary of Surface Water and Seep Quality Data for Net Depot Area
Sheet 2 of 2
Fluoranthene
lndeno( 1 ,2,3-c,d)Pyrene
Total cPAHs
Pesticide/PCBs in pgA
4,4'-DDD
4,4'-DDE
4,4'-DDT
Aldrin
PCB-1254
PCB-1 260
Total PCBs
Total Petroleum Hydrocarbons
Diesel
Oil
Detection
Frequency
0/4
0/4
0/4
0/4
1/4
1/4
0/4
0/4
0/4
0/4
in mg/L
0/4
0/4
Maximum
Detection
ND
ND
ND
ND
0.0021
0.0032
ND
ND
ND
ND
ND
ND
Seep
Screening
Level (2)
300
300
0.001
0.001
0.001
0.0019
0.03
0.03
0.03
1
1
Discharge
Exceedence
Frequency ( 1 )
0/4
0/4
0/0
1/1
1/1
0/0
0/0
0/0
0/0
0/4
0/4
(1) Undetected sample results with quantitation limits greater than screening levels were excluded from
exceedence frequency calculations.
(2) Seep discharge screening level based on protection of marine aquatic life.
419119/ROD-Revised.xls Table 9
Hart Crowser
MI9M9
Page 63
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Table 10 Summary of Sediment Quality Data for Clam Bay
Sheet 1 of" 2
Total Metals in mg/kg
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
Semivolatiles in mg/kg OC
Benzo( a)Anthracene
Benzo(a)Pyrene
Di-N-Butylphthalate
Dibenzo(a,h)Anthracene
Fluoranthene
lndeno( 1 ,2,3<,d)Pyrene
Total Benzofluoranthenes
Semivolatiles in Mg/kg
2,4-Dimethylphenol
Pesticide/PCBs in ug/kg
4,4'-DDD
4,4'-DDE
4,4'-DDT
Aldrin
Total PCBs
Dioxins in ng/kg
2378-TCDD
12378-PeCDD
123478-HxCDD
123678-HxCDD
123789-HxCDD
1234678-HpCDD
OCDD
Detection
Frequency
23/68
77/78
22/23
52/78
76/78
76/78
70/78
16/16
59/77
23/23
0/23
23/78
6/23
16/16
78/78
14/27
12/27
2/17
1/27 '
21/27
10/27
15/27
1/17
4/17
6/17
5/17
1/17
68/93
4/7
3/5
2/5
3/5
4/5
8/8
9/9
Maximum Screening Exceedence
Detection Level Frequency (1)
41.5
56.5
0.4 P
8.35
184.2 J
19400
1510
703
0.489
494
N/A
5.5 N
0.33 J
111
3100
37.975
27.848
19 J
7.468
167.5
24.051
70.89
92
6.4 J
2
170
0.4
6470
2.7 )
7.5 J
5.3 )
18 )
188 J
103
1760
57
5.1
260
390
450
0.41
6.1
410
110
99
220
12
160
34
230
29
130
0/78
2/78
0/78
6/78
4/78.
3/77
0/78
15/78
0/27
0/27
0/17
0/27
1/27
0/27
0/27
1/17
23/92
Hart Crowser
H19I-I9
Page 64
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Table 10 Summary of Sediment Quality Data for Clam Bay Sheet 2 of 2
_ Detection Maximum Screening Exceedence
Frequency Detection Level Frequency ( 1 )
2378-TCDF
12378-PeCDF
23478-PeCDF
123478-HxCDF
123678-HxCDF
123789-HxCDF
234678-HxCDF
1234678-HpCDF
1234789-HpCDF
OCDF
2378-TCDD Equivalents
4/5
4/5
4/5
4/5
4/5
3/5
5/5
5/5
3/5
5/5
9/9
23.3
18.8 J
33.5
83.8
27.1 J
1.4 J
37.2 J
109
7.5 J
94.3
51
(1) Undetected sample results with quantitation limits greater than screening levels were excluded from
exceedence frequency calculations.
419119/ROD-Revised.xls Table 10
Han Oowser Page 6 5
H'91-19
-------
Table 11 Summary of Tissue Quality Data for Clam Bay
-
Total Metals in nig/kg
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Manganese
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Semivolatiles in ugAg
2 ,4-Dim ethylph enol
8enzo(a)Anthracene
Benzo(a)Pyrene
Ben2o(b)Fluoranthene
Dibenzo(a,h)Anthracene
Di-N-Butyiphthalate
Fluoranthene
lndeno( 1 ,2,3<.d)Pyrene
Pestictde/PCBs in ugAg
4,4'-DDD
4,4'-DDE
4,4'-DDT
Aldrin
Total PCBs
Dioxins in ng/kg
2378-TCDD
12378-PeCDD
123478-HxCDD
123678-HxCDD
123789-HxCDD
1234678-HpCDD
OCDD
2378-TCDF
12378-PeCDF
23478-PeCDF
123478-HxCDF
123678-HxCDF
123789-HxCDF
234678-HxCDF
1234678-HpCDF
1234789-HpCDF
OCDF
2378-TCDD Equivalents
Detection
Frequency
0/7
14/14
0/7
13/14
10/14
14/14
10/14
14/14
9/14
13/14
10/14
13/14
0/7
14/14
0/7
9/16
9/16
9/16
7/16
0/7
11/16
9/16
4/16
9/16
5/16
0/16
13/16
2/5
0/4
0/4
1/4
0/4
5/6
6/6
4/4
0/4
1/4
1/4
0/4
0/4
1/4
2/4
0/4
1/4
6/6
Maximum
Detection
ND
16
ND
0.5
1.6
76.16 J
3.4882 J
211
0.0544 j
2
6
1.2 J
ND
53.9
ND
21.42
6.174
10.458
0.504
ND
75.6
3.024
3.422
7.198
36
ND
656.727
0.48
ND
ND
0.81
ND-
4.9
31.5
0.86
ND
0.62
0.57
ND
ND
0.17
1.2
ND
1.9
0.69
Screening Exceedence
Level Frequency ( 1 )
0.54
4.5
0.0007
0.68
6.8
50
6.8
0.41
27
6.8
6.8
0.11
410
27
4.3
0.59
4.3
0.43
54000
4.3
13
9.3
9.3
0.24
14
0.09
0.04
0.2
0.69
0.2
2.5
20
0.79
0.4
0.4
0.2
0.2
0.2
0.23
2
2
20
1/14
0/0
0/14
0/14
1/14
2/14
0/14
0/14
0/14
0/14
0/1
0/14
0/0
1/9
6/9
1/9
1/9
0/16
0/9
0/15
0/16
1/16
0/6
13/13
2/4
0/0
0/4
1/4
0/4
2/6
2/6
1/4
0/4
1/4
1/4
0/2
0/4
0/4
0/4
0/4
0/4
(1) Undetected sample resurts with quantitation limits greater than screening levels were excluded from
exceedence frequency calculations.
419119/ROD-Revisedxls Table 11
Hart Crowser
H19M9
Page 66
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Table 12 - Maximum Concentrations Detected in Site Media
Maximum Delectec
Chemical of Concern
INORGANICS:
Arsenic
Asbestos
Cadmium
Copper
Lead
Nickel
Silver
Zinc
OKGANICS:
Vinyl Chloride
2,4 Dimelhylphenol
Total PCBs
2,3,7,8-TCDD Lquiv.
Tl't 1 (as diesel)
Maximum
Delected Soil
Concentration
in mg/kg
52.3
(b)
22800
23400
56000
926
67600
23800
0.2tt
NO
8.9
0.026
1 5000
Maximum
Detected Sediment
Concentration
in mg/kg
56.5
NA
8.35
19400
1510
494
5.5
3100
NA
0.092
6.47
0.000051
NA
Maximum Delected
Groundwater
Concentration (a)
in ug/L
109
NA
13.1 (c)
179(c)
7.2 (c)
252 (c)
1.6(c)
5740 (c)
ND
ND
ND
0.00036 (d)
1100
Maximum
Detected Seep
Concentration
in ug/L
ND
NA
4-2 J (c)
30.6 (c)
1 (c)
47.3 (c)
0.78 J (c)
232 (c)
ND
ND
0.12
NA
ND
Shellfish Tissue
Concentration
in ug/kg
(wet weight)
16000
NA
500
76200 I
3490 J
2000
1200 J
53900
NA
ND
660
0.00069
NA
concentration.
NA Not analyzed.
ND Not delected.
Notes:
(a) Grouiulwaler samples collected from (he landfill area unless otherwise noted.
(b) Two sampler collected from test pits in the landfill area contained 75 to 80 percent fibrous asbestos. Asbestos was not
observed in any other site areas.
(c) Dissolved (OiKcnlr.ilioii
(d) dmuiulwalcr sample collected from the Oulwash Channel Aquifer.
I T.M I'J/KOO KeviiccI 0> Table I.'
-------
Table 13 TPH SoU-to-Leachate Ratios in Fire Training Area
Sample ID
94MAN001B10
94MAN002B11
94MAN002B13
94MAN002B14
94MAN003B12
94MAN003B13
Sample
Depth
in Feet
0 to 2.5
2.5 to 5
2.5 to 5
2.5 to 5
5 to 7.5
5 to 7.5
TPH TPH Soil/Leachate
Soil Cone. SPLP Cone. Ratio
in mg/kg in mg/L Unitless
7,970
13,990
10,700
1 5,840
1,140
11,650
1.25 UJ
2 J
2
2.5 UJ
1.13 J
2.7
>6,376
6.995
5,350
>6,336
1,009
4,315
Notes:
* TPH is sum of diesel and oil fractions
> Soil-to-Leachate ratio is minimum value, based on nondetected leachate concentration
UJ = Not detected at estimated detection limit indicated
J = Estimated value
419119/ROD-Revised.xls Table 13
Hart Crowser
1-4191-19
Page 68
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Table 14 - Summary of Cumulative Baseline Cancer Risks and Hazard Indices, Manchester Annex Site
-
Exposure Scenario
On-Site Worker
Occasional Site Visitor (Child)
Subsistence Fisher
Cancer
Average
Exposure
4.E-06
-
2.E-05
Risk
Reasonable
Maximum
Exposure
9.E-04
1.E-03
6.E-05
Hazard
Average
Exposure
0.4
-
0.7
Index
Reasonable
Maximum
Exposure
260
1,000
3
419119/ROD-Revised.xls Table 14
Hart Oowser
H'91-19
Page 69
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Table 15 - Summary of Manchester Annex Cleanup Levels and Cleanup Goals
Chemical of Concern
Landfill Area - Seeps
Copper
Nickel
Zinc:
Total PCUs
Clam Bay - Sediments
Copper
lead
Silver
Zinc
2,4-Dimelhylphenol
Total PCBs
Clam Bay Tissue
Tolal PCUs
Fire Training Area - Soil
2,3,7,8-TCDD Equiv.
TPI 1 (as diesel)
Cleanup
Level
10.6ug/L
7.9 ug/L
77 ug/L
0.03 ug/L
390 mg/kg dry
450 nig/kg dry
6.1 mg/kg dry
410 mg/kg dry
29 ug/kg dry
1 30 ug/kg dry
N/A (b)
270ng/kg
N/A (d)
Basis
Regional background
WAC 1 73-201 A marine chronic
WAC 1 73-201 A marine chronic
WAC 1 73-201 A marine chronic
WAC 1 73-204 SQS
WAC 1 73-204 SQS
WAC 1 73-204 SQS
WAC 173-204 SQS
WAC 1 73-204 SQS
Lowest AET (Ecology, 1988)
WAC 173-3 40 Method C
Cleanup
Goal
40 ug/kg dry
42 ug/kg wet (c)
200 mg/kg
Basis
Bioaccumulation correlation (esl.)
Subsistence fishing
WAC 1 73-340 Method A
Point of
Compliance
Seep Discharge
Seep Discharge
Seep Discharge
Seep Discharge
0 to 10cm depth
0 to 10 cm depth
0 to 10 cm depth
0 to 10cm depth
0 to 10 cm depth
0 to 10 cm depth
Inlertidal clams
Olo 15 ft depth
NOTHS:
a) Imullicienl loxicily data are available lo derive a reliable sediment cleanup level for nickel (reduction of nickel concentrations will result from attainment of other chemical cleanup levels).
b) I xisling (baseline) site concentrations are al or below risk-based cleanup levels except for the subsistence fishing scenario.
c| A tissue PCB cleanup goal of 42 ug/kg wet weight is associated with a cumulative cancer risk of I K 10'* for a subsistence fishing scenario. Risks associated with subsistence fishing
can be controlled by implementing temporary limitations on subsistence-level consumption during the initial recovery period.
d) Site-specific risk assessment and teachability testing indicated only a low risk associated with TPH; consequently, no chemical-specific cleanup level is necessary.
4 191 19/KOO-Kevised.»li - Table I 5
OQ
--j
o
-------
Table 16 Estimated Areas and Volumes Exceeding Soil and Sediment Cleanup Levels
Description
Landfill and Clam Bay (1)
Landfill debris and cap material
Silt basin offshore of north end of landfill
Intertidal surficial sediments
Fire Training Area (2)
Debris inside simulators
Dioxin-impacted surficial soil around simulators
Debris/soil pile north of main simulator complex
Soil at main simulator complex exceeding cleanup goal for TPH (3)
Soil at former fire training stations and UST exceeding cleanup goal for TPH (3)
Net Depot and Manchester State Park
Complies with soil and sediment cleanup levels
Average
Area Depth
in sq ft M) in Feet
270,000
2,700
210,000
2,600
3,200
830
30,000
3,400
7
8
0.5
2
1
4
8
4
Volume
inCY'41
70,000
800
3,900
190
120
120
8,800
500
(1) Soil and sediment areas exceeding cleanup levels in the landfill area and Clam Bay are shown on Figure 7.
(2) Soil areas exceeding cleanup levels and cleanup goals in the Fire Training Area are shown on Figure 8.
(3) No cleanup level has been established for TPH.
(4) Area and volume estimates are provided to two significant figures.
419119/ROD-Revisedxls - Table 16
Hart Crowser
1-4191-19
Page 71
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Vicinity Map
Manchester Annex Superfund Site
Point Wh.te ;*
H
Point Glover
- V
>& v '
-I
\ \
nan Point_--r, ~^.i,A
.CWautaupa
' '-I Beach
~ 10
\ \i
b t.-.i.
» i i -. «
^ ~
Beans Point* "*-
J-
X
(^
HOOOC**.../
I
- I
^
^- <
V
COUNTY ___ ' " v
Note. Base map prepared from uSGS " 5 "i:nute
quadrangle ol Bremerton Eas: .vasnmgton
dated 1981
0 2000
5^
Scale in Feet
4000
Regional Map
NOT TO SCALE
HAKTOROWSCR
J-4191-19 10/97
Figure 1
-------
rvo
1.400 4«lk pep 4IVI1V03
Site Features Map
Manchester State Par><'
Property Boundory
Sedimenta
Moin Simulator
Complex
Geologic Cross Section Location
0 400
Scale in Teet
800
-------
Geologic Cross Sect/on
West
40 r
20
u_
c
I
5
c o
-20 «-
ut
2
in
£=st
a.
o.
H-
»
o
OL
O.
Cove'
Deeo
Proglaciol
Deposits
-v
O
o
i Q.
ffl »-
a» a
-Londfill Waste
o r-
CM CM
I t
a. a.
o» CD
N
PEAT
Siitv """
SANO/SHELLS SANy0
x,. Recent 3eacn
*^**^.^ Desosits
Scncy SiL*
LJ
m
Offset Distance and Direction
Exploration Number
T Boring/Monitoring Well Location
Water Level At Time of Drilling
I Screened Section
Horizontal Scale in Fee:
0 200
0 20 40
Vertical Sec e in Feet
Vertical Exaggeration x'Q
Soil Containing
FineGrained
(Silt or Clay) Mctrx
Test Pit Lsca:ion
It
? t
en
J-4191-19
Figure 3
9/97
-------
GroundwaIer Elevation Contour Map
Wet Season - March 1995
\
1.000 **!»
^iw-oi
V'vsrly Bounder -.
*v^>
/ /
/ / /v
J / /
* A tlA
I f
NAVV4 «
U.84
9NAVYff
MW-07 HI/PS Uonillxmg *tO""g We' ocol.on o"fl
OSW-OI .R'/rS Su'loce Wolrr/'icr..^ Sompifl
0BW-01
io..iil.;>- unO N.J".I:.
Suflicial f.ll/Landliii ^one
Oulooth Cnonntl/Uecp I'l'
Craundnroitr Citvolio" m '
500
J-418MB
4
6/07
-------
Conceptual Model - Human Health Risk Assessment
Manchester Annex Site
Source
Simulators
USTs
landdll Waste
Landfill Waste
Receiving Media
Surface and
Subsurface Soils
IntetlKjal Sediments
Migration Pathway
Wind Erosion
Sort Leaching.
Groundwaler Transport
and Seepage
Surface Water
Runoff/Erosion
Wave Erosion
Exposure Media
Oust and Vapor
Surface and
Subsurface Soils
p- Outv
Lr~s«
Oulwash Aquifer
Surface Water
Clam Bay
h\
Intertidal and
SubtkJai Sediments
Aquatic Biota
Receptors and Routes
of Exposure
Site Workers and Visitors
liilialcilun
Site Wtxkeis and Visitors
Diieci Contact
SltcW.xkPIS ViSillUS 0»Cl
Ne.vhv Hr>5,ir1o"ls
D""k'ii| W.ilo
Recrenlionol. Commercial,
and Subsistence Fishers
Fish and Sl«niish
Consumption
HAKTCROWSW
J-4191-19 9197
flguns
-------
Baseline Exposure Pathways
Exposure Point
(Fish/Sriellfish
Ingeslion) -
Exposure Point:
(Dermal Contact and
Soil Ingeslion Routes;
Inhalation Exposure Route
Ambient Air and
Windblown (Oust)
Release Mechanism:
(Soil Disturbance and
Dust Generation)
Source: Surface Soils
Exposure Point
Drinking Water
! fy\ Consumption
xxxxxxxxxxxxxxxxxxxxxxxxyxxxxx/xxxxxxx^
vx x x x / x x x Transport Medium
x / x / x (Groundwater)
XXXXXXXX XX X X X X X
Dilnklng Water Well
Grounrtwater Flow
Direction
NO TO SCALE
-------
Areas Exceeding Soil and Sediment Cleanup
Levels in Landfill and Clam Bay
Approximate
Landfill
Boundary
Intertidal Sorficfal Sediments
N
i
HARTOtOWS&l
J-4191-19 9/97
Figure 7
-------
Areas Exceeding Soil Cleanup Levels and Goals
in Fire Training Area
Debris/Soil Pile ..
Exceeding Cleanup^
Level for Dioxins ,
Soil Exceeding
Cleanup Cool
for-TPH
' Surficiol Soil v
,_Exceeding Cleonup
-Tevet
-Debris Inside i.
Simulafors "Exceeding
1 ' Cleanup. Level for Dioxins
i
1
M
0 150
=S^=^=2=
Scale'in Feet
300
a
9 :
HARTCKOWSER
J-4191-19 9/97
Figure 8
-------
A/fernat/ves 2A and 3A
Approximate Area/ Extent of Landfill Cap and Hydraulic Cutoff System
O
N
\
0 150
M
Scole in feet
300
-------
Alternative 2A - Armoring over Intertidal Debris
Typical Section
Rock ond Cobble Armor Loyer
Clisting Crode
Londlill Debris
Pea Grovel
(or equivalent)
-10-
20
15
OJ
o
£
k.
9)
o:
o
z
10
Horizontal Scale in Feet
0 20
0 10
Vertical Scale in Feet
Vertical Exaggeration x 2
-10
20
0)
u.
c
o
-------
Alternative 3A - Excavation of Intettidal Debris
and P/acemenf of Design Fill
Typical Section
15
9 10
o
c 0
o
T>
flj
-Id
listing Cover Soil
-Landfill Cop
-Pea Gravel (or equivalent)
Erosion Protection and
Habit o I Enhancement Material
Sandy Sll I
Grade
MLLWl
20
a>
a>
«
0)
15
o
10
u
4>
5 c
n
o
0 o
4)
Horizontal Scale in Feet
0 20
0 10
Vertical Sralr> in Feet
Vertical txaggeration x 2
40
a
20
-------
ATTACHMENT A
RESPONSIVENESS SUMMARY
-------
ATTACHMENT A
RESPONSIVENESS SUMMARY
INTRODUCTION
This Responsiveness Summary addresses comments on the Proposed Plan for
Site Cleanup, Manchester Annex Superfund Site, Manchester, Washington,
dated March 1997. The public comment period for the Proposed Plan was from
April 2 to May 2, 1997, and a Public Meeting was held on April 16, 1997, at the
Manchester Public Library in Manchester, Washington. In addition, two briefings
were held at the Manchester Environmental Laboratory on March 31, 1997, for
employees of EPA, the Washington State Department of Ecology, and the
National Marine Fisheries Service, who work at the site. Questions and
comments received during both the employee briefings and the public
comment period are addressed in this responsiveness summary.
SUMMARY OF COMMENTS
In total> 54 comments were submitted to the Corps concerning the Proposed
Plan. Comments were received from the following sources:
* Three verbal comments were received during the Public Meeting;
* One written comment was submitted on the comment form which
accompanied the Proposed Plan;
+. Twenty-one verbal comments were received during the two employee
briefings held at the Manchester Environmental Laboratory;
* Two verbal comments were received by phone from Washington State
offices; and
* Twenty-seven written comments were submitted by three branches of EPA:
Nine comments from the Director of EPA's Facilities Management and
Services Division (FMSD);
Eleven comments from the Director of the EPA Manchester Laboratory;
and
Seven comments from the Director of EPA's Office of Management
Programs (OMP).
HartCrowser Page A-1
J-419M9
-------
Copies of the transcripts for the Public Meeting are available at the public
repositories listed in the Community Participation section of the Record of
Decision, and a copy is part of the Administrative Record. Copies of the letters
received and conversation records have been included in the Administrative
Record.
RESPONSE TO COMMENTS
The comments and accompanying responses are arranged under the following
eight topics:
1. Remedial Action Preferences
2. Health and Safety Concerns
3. Environmental Concerns
4. Remedial Design Issues
5. Remedial Action Implementation Issues
6. Post-Remedial Operation, Maintenance, and Monitoring Issues
7. Coordination with Other Agencies/Programs
8. Other Issues
Those comments which apply to more than one topic appear under the heading
considered the most appropriate. Public comments are addressed first within
each topic. Paraphrasing was used to incorporate related concerns expressed in
more than one comment. Every attempt has been made to accurately represent
and to respond to all comments received.
1. Remedial Action Preferences
Comment la. [Public Meetingj I'm Richard Brooks with the Suquamish Tribe.
We support the preferred alternative. Alternative 3A.
Response: Comment noted
Comment 1b. [Mail-in) I prefer the Alternative 3A for the Landfill & Clam Bay
sediments and Alternative 2B for the Fire Training Area.
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Response: Comment noted.
Comment 1c. [C Hossum, Agency for Toxic Substances and Disease Registry] I
just got a copy of the proposed plan for cleanup at Manchester dated March
'97, and it looks great It looks like a wonderful idea to get the information out
too. As far as the plan goes, I have no problem with it I think the preferred
alternatives are fine from our stand point
Response: Comment noted.
Comment Id. [EPA OMPj I concur with the recommendation of cleanup
alternative 3A for the landfill and Clam Bay sediments and cleanup alternative
2B for the Fire Training Area. It must be emphasized, however, that regardless of
the remediation undertaken, the final ratification will be the monitoring results
for the site. If the proposed alternative does not result in the site being judged
acceptable within existing environmental parameters, further remediation will
have to be undertaken by the Department of Defense or the U.S. Army Corps of
Engineers.
Response: Comment noted.
2. Health and Safety Concerns
Comment 2a. [Employee Briefing] A lot of us are concerned about the health
and safety of the employees working at the laboratory as well as the potential
contamination problems we may have inside the laboratory during the
excavation and movement of the shoreline debris. Do you plan to prepare a site
safety and health plan that will address these concerns?
Response: A Site Safety and Health Plan (SSHP) will be prepared by the
construction contractor. The design will require the contractor to consider
these factors in his SSHP submittal.
Comment 2b. [Employee Briefing] What do you plan to do to reduce or
eliminate the off-gassing of the vinyl chloride and other volatile materials during
the excavation and spreading of the sediments and soils on the landfill?
Response: Vinyl chloride was only detected at very low concentrations
(maximum concentration of 0.28 pans per million) in a couple of areas of
the upland landfill. Volatile materials are not expected to be a problem at (he
toe of the landfill because of the high energy environment. And only low
concentrations would be expected in the upland landfill, because of the age
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of the landfill. The SSHP prepared by the construction contractor will
- address air monitoring during construction activities.
Comment 2c. [Employee Briefing] Is there any danger if someone walks around
the landfill now?
Response: No. Risks are minor unless someone digs down below the
existing soil cap that the Navy placed over the landfill. As a precaution, the
EPA Lab has posted the landfill area with "Keep Out" signs.
Comment 2d. [Employee Briefing] How close is the contaminated area to the
laboratory buildings?
Response: The nearest portion of the landfill is about 150 to 200 feet from
the office building.
Comment 2e. [Employee Briefing] I have a concern about enforcement of the
restriction on subsistence shellfish harvesting. 1 think that in reality it will be
difficult to tell whether someone is a recreational or a subsistence harvester.
Response: Results of the baseline risk assessment performed for the site
indicate that potential health risks associated with subsistence-level
consumption of shell fish collected from the intertidal area of Clam Bay are
above levels targeted by the state cleanup program. The amount of shell fish
consumed by the subsistence-level harvester was assumed in the risk
assessment to be approximately 23 kg (or about 150 meals) per year. There
is currently a restriction on both recreational and subsistence-level shellfish
harvesting in Clam Bay. However, if the restriction were not in place, it is
unlikely that current conditions in the intertidal area could support this high
level of shellfish harvesting. The Suquamish Tribe has preliminary plans to
conduct shellfish enhancement activities at the site after completion of
construction activities. A restriction on subsistence-level shellfish harvesting
will remain in-place after remedial construction, until the Washington State
Department of Health and the Suquamish Tribe determine that the shellfish
are safe for subsistence-level harvesting. The Suquamish Tribe will be
responsible for enforcing this restriction.
Comment 2f. [EPA Manchester Lab] Our primary concern is for the health and
safety of the employees and contractors who work at the laboratory facility and
how they will be protected during the cleanup activities. Besides a strong moral
commitment, we are required by law to provide a safe and healthful workplace
for these employees. A critical part of the cleanup will be the design and
implementation of the site safety and health plan for this project. We request
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that the U.S. Army Corps of Engineers and their contractors work closely with us
in designing this plan so that the work can be accomplished without exposing
"the laboratory workers to asbestos fibers, harmful dusts and vapors, noise or
other hazards. The close proximity of the landfill to our facility creates special
exposure problems and we want to advise, review and concur on the site safety
and health plan before the cleanup project begins.
Response: The health and safety of contractors and site employees is of
utmost concern to the Corps and the Superfund'program. The EPA Lab will
be given opportunity to provide input, review, and comment on the Site
Safety and Health Plan before construction activities begin.
Comment 2g. [EPA Manchester Lab) The site safety and health plan should
include a comprehensive air and noise monitoring scheme that includes real-
time as well as standard industrial hygiene monitoring of these hazards. The
shoreline area contains substantial quantities of asbestos debris as well as
metals, PCBs, and other contaminants. We are concerned about the potential
generation of asbestos fibers and harmful dusts during the cleanup work. The
fresh air intake that supplies air to the laboratory is located on the south side of
the laboratory mechanical room and the ventilation pumps and air intakes for
the Office Building are located on top of this structure. Both of these fresh air
intakes are located close to the old landfill. What type of dust controls will be
used to control the generation of paniculate during the construction activities?
Will provisions be made to monitor for paniculate at these locations and
contingencies implemented to stop work if airborne levels exceed agreed to
action levels?
Response: Specific dust control measures will be presented in a Remedial
Action Management Plan (RAMP), which will be developed by the Corps
and approved by EPA prior to site work. The EPA Lab will be given
opportunity to review, comment, and provide input to the RAMP. Examples
of dust control measures which maybe used include the following:
1) Spraying with water or oil/water emulsion to control dust.
2) Speed limits for trucks on site to minimize dust generation.
3) Sequencing or phasing of work to minimize generation of dust.
A real-time air monitoring program will be instituted to monitor dust levels.
Contingencies will be in place to stop or modify work if dust exceeds agreed
upon action levels. The dust action levels and required construction actions
will be described in detail in the RAMP. Asbestos and other landfill
contaminants will be addressed in the construction monitoring plan.
Comment 2h. (EPA OMP] We want to ensure that neither the health of our
employees nor the quality of our lab analyses is compromised. The fresh air
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intakes for our lab are situated on top of the building in such close proximity to
th« remediation site that it would be advisable for US Corps to undertake
monitoring at the fresh air intake and inside the lab.
Response: See response to Comment 2g. The merits of monitoring at the
fresh air intakes and/or inside the lab will be considered during development
of the RAMP. Monitoring immediately downwind of construction activities
will be a key component of the monitoring program, since paniculate
concentrations will be highest dose to the source.
3. Environmental Concerns
Comment 3a. [Public Meeting] I'm Ann Boeholt with the Department of Fish &
Wildlife. My comment is that the comment was made that mitigation is not
going to be required with the preferred alternative for the toe of the landfill. I
would like to say that, from our standpoint that has not been ascertained as of
yet; it sounds like, for one, that there may still be some armoring required of the
bank. And certainly, even though there would be excavation rather than simply
capping what's there, the excavation will cause disturbance of the existing toe
and so there may be mitigation. Not to the extent that there would be with
Alternative 2A.
Response: Comment noted. The objective of this alternative is to minimize
the impact to the aquatic habitat and maximize long-term beach stability.
This alternative was selected, following extensive input and discussion by the
Manchester Work Croup, to avoid the need for mitigation measures
included in other alternatives considered. We will continue to coordinate
with the Work Croup (of which WDFWis a member) throughout design and
construction to achieve the remedial action goals, including no net loss of
habitat function.
Comment 3b. [Employee Briefing] Can you discuss some mitigation ideas for the
landfill wetlands? Would it be possible to do the mitigation in Beaver Creek
above the Navy pond?
Response: A determination regarding whether mitigation is required has not
yet been made. If mitigation is required, the most likely area is currently
thought to be enhancement of the wetlands on the south side of the landfill
or in the Beaver Creek drainage above the Navy ponds.
Comment 3c. [Employee Briefing] Do you know if the stream on the west side
of the landfill is picking up any leached material now?
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Response: Most of the stream flow is rainfall runoff. The remedial action
includes installation of a curtain drain (hydraulic cutoff system) around the
- perimeter of the landfill, including the west side. The curtain drain will be
designed to intercept shallow groundwater and rainfall runoff prior coming
in contact with the landfill.
4. Remedial Design Issues
Comment 4a. [Employee Briefing] Will the access road to the laboratory be
raised along with the landfill?
Response: This is a design question that will be decided during the remedial
design phase. It will either be left as it is and the landfill graded in or the road
will be raised.
Comment 4b. [Employee Briefing] Do you know if PCB fluid is in the UST tanks?
Will all fluids be pumped out of the USTs?
Response: When the concrete USTs were sampled and tested, sludge and
PCBs were found in them. The sludge and PCBs will be removed prior to in-
place closure of the USTs. Associated piping also will be removed if possible.
If existing utility lines make it impractical to remove some piping, those pipes
will be purged in-place and abandoned.
Comment 4c. [EPA FMSDJ The master plan for the Manchester Lab calls for the
expansion of existing laboratories which would require the construction of
additional parking over the area of the landfill. Any remediation solution should
not unnecessarily impinge upon the ability of the Manchester Lab to carry out its
master plan. In this case, all proposed landfills should be designed and placed to
a degree sufficient to support the proposed future parking areas.
Response: The landfill cap will be designed in such a way that it will be
compatible with construction of a future parking lot on the northern portion
of the landfill.
Comment 4d. [EPA Manchester Lab] A Facility Master Plan for the projected use
and expansion of the laboratory facility was completed in 1994. A copy of this
plan was sent to the US Corps as a part of our original comments during the
RI/FS comment period. The Master Plan contemplates a parking area
immediately south of the laboratory for employee parking allowing building
expansion to the north into the existing parking lot. We request that the landfill
cap and new roadway be designed so that EPA can utilize this area as projected
in the Master Plan. The proposed fill area should be designed so that the
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northern portion of the site is level and as near current grade as possible to
allow for future utilization as the laboratory's parking area.
Response: See response to Comment 4c.
Comment 4e. [EPA OMPJ Upon completion of the remediation, it appears that
the main entrance road to the lab will need to be rebuilt above the proposed
cap. Since the lab's Master Plan calls for significant construction in the future,
the reconstructed road should be built to meet the same design criteria as our
existing road, which is capable of supporting heavy equipment and tank trucks.
If the roadway is to be re-routed, consideration must be given to the impact on
the main lab entrance as described in the Master Plan.
Response: If the existing access road is demolished, an access road with the
same design criteria as the ex/sting road will be included in the design
specifications.
Comment 4f. [EPA FMSD] Although the proposed plan indicates the cap will be
designed to control infiltration of rainwater, the preferred alternative 3A does
not specify that the cap will include revegetation. Please provide clarification on
whether appropriate grading and revegetation will be included in the preferred
alternative 3A for the landfill. In addition, consideration should be given to
designing the fill contours to include berms to screen future parking, and allow
the Entrance Road alignment and grades to enhance views of Clam Bay and to
promote safe traffic flow of employees and guests as well as service vehicles.
Response: Aesthetic concerns will be considered in the remedial design and
will be coordinated with landowners. Appropriate grading and revegetation
will be included as part of the landfill cap design. The Corps will solicit input
from EPA (as property owner) through the Manchester Work Croup.
Comment 4g. [EPA Manchester Lab] The design and construction of the landfill
cap will affect the character of the laboratory and the site very possibly in
perpetuity. The cap should include berms to screen some areas of the site. Road
alignment and grades should promote safe traffic flow for employees, guests,
and service vehicles and enhance views of the bay. We request that the landfill
cap be designed with the assistance of a landscape architect to ensure that it is
done in a functional and aesthetically pleasing way.
Response: See response to Comment 4f.
Comment 4h. [EPA Manchester Lab| A large (30-inch?) storm water drain line
runs from just north of the Laboratory Annex Building to the southeast and into
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Clam Bay. This concrete pipe likely allows some backflow of seawater into the
landfill. The possible leakage of the pipe could add water to the landfill or
conversely, the pipe might act as a drain for it Tnis storm line drain (and any
others) should be eliminated or rerouted.
Response: The need to plug and/or reroute existing storm drains in the
vicinity of planned construction activities will be evaluated during the design
phase. The Corps will coordinate with EPA Lab if the design team determines
that modifications are necessary which could impact facility operations.
Comment 4i. [EPA Manchester Laboratory] We have technical questions and
comments that we anticipate being addressed during the design phase of this
project Some of these questions and comments are as follows:
a. The material on the beach, primarily consolidated metal debris, may be
extremely difficult to break up, remove from the beach, and place on the upland
portion of the fill. The material may be difficult to properly compact leaving
voids present throughout the landfill. This could cause differential settlement and
cracking of the cap. The structural stability of the fill could be particularly
important if the access road is to be placed across it in its existing alignment.
How do you plan to break up the debris material to spread it over the landfill
portion of the site prior to capping?
b. There are no details on the design fill except that it is anticipated that the fill
will mitigate the concentration of metals in the seeps. The FS indicates at 4-12
that the fill should result in order of magnitude reduction in the concentration of
seeps, thus meeting Remedial Action Objectives. There is no indication of what
will happen if this does not occur or whether some subsequent remedial action
would be required. The intertidal fill will apparently lower the tidal influence on
the landfill. However, because it is "semi-permeable" the intertidal design fill will
allow some infiltration into the landfill material at high tide or repeated high
water, further contributing to seeps.
c. There are no details on the nature of the dike to be constructed to protect the
excavation from the tidal movement.
d. There is no information on the relative importance of groundwater versus
precipitation versus saltwater infiltration on creation of seeps from the landfill.
We could not find technical information in the RI/FS about the groundwater
flow in the landfill. It is assumed that the groundwater cutoff will result in a
significant reduction of flow into the landfill and a resulting significant reduction
of seeps.
e. From the Feasibility Study, the cross section of the trench indicates that the
trench is lined with a fabric but not an impermeable membrane. Therefore, this
would appear to do little to cut off the groundwater except to provide an
alternate, more permeable pathway for groundwater to leave the area. Since the
trench is keyed into the sandy silt, it would appear that the trench is deep
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enough (elevations are not provided) to allow the free movement of saltwater
back into the trench system at high tides. This would expose the landfill to an
additional source of water which presently does not exist Also, groundwater
would not flow out of the trench at high tides. We would like to review
elevations, slopes of the trench, and the construction details during the design.
One suggestion is that the gravel cutoff trench be replaced with a slurry wall or
some other form of an impermeable barrier to groundwater flow. The
groundwater would be diverted around the fill as with the trench but in a more
positive manner. A wall that would be keyed into the sandy silt layer and the
design fill on the intertidal area would not provide a conduit for saltwater
backing up into the fill.
A slurry wall would be more expensive than the gravel trench and require more
difficult and involved construction. An alternative would be the use of an
impermeable membrane on the downstream, landfill side of the gravel trench.
This would eliminate any groundwater flow into the landfill but would not
eliminate potential flow of saltwater back into the trench system. Depending on
the hydrogeology at the site, a drainage system may be necessary outside of the
low permeable barrier surrounding the landfill.
f. The specific design for the landfill cap has not been determined. The FS at 4.4
talks about the lack of a need for a RCRA cap on die landfill because lead levels
in the seeps are below Remedial Action Objectives. However, several other
metals and PCBs which are also of concern. The concerns for any cap are the
requirements to protect against direct contact with the fill, the reduction of
precipitation and infiltration, and stability and reliability over time. One of the
decisions to be made during the design is what type of a cap can meet these
objectives.
Response: Comments noted. These concerns and questions will be
addressed during the design phase. The EPA Lab will have an opportunity to
review design and construction documents produced during the cleanup
project.
5. Remedial Action Implementation Issues
Comment 5a. [Employee Briefing] I am concerned about the cleanup and
tracking of mud from the contaminated area onto private vehicles, delivery
trucks, and other vehicles entering and leaving the laboratory and the site during
the construction activities. What will be done to eliminate the spreading of the
contaminated soils and sediments out of the contaminated work area?
Response: A decontamination area will be set up to prevent movement of
soils and mud outside the remediation area. Area acc^s and movement of
vehicles will also be controlled with temporary fencing.
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Comment 5b. [Employee Briefing] There may be a lot of vibrations that affect
some of the sensitive laboratory instruments during the cleanup construction
activities.
Response: This will be addressed in the design phase, with the lab's input
Comment 5c. [Employee Briefing] The Old Navy Dump/Manchester Superfund
Site Schedule handout indicates that you plan to start the cleanup work in the
summer/fall of 1998. How long will it take to move the shoreline debris and
spread this material over the landfill area?
Response: Many details have to be considered before a reliable estimate
can be made. It depends on the design and the contractor's capability. The
diking and excavation of the landfill debris alone may take 6 months.
Comment 5d. [Employee Briefing] What kind of mechanical processes and
equipment will be used to excavate the shoreline debris?
Response: We plan to construct a dike to stop the tidal flow to be able to
work at the toe of the landfill. We anticipate the contractor will use a large
piece of equipment to pull out chunks of debris, and that a hydraulic sheer
will be used to cut the material. The material will be consolidated on the
upland portion of the landfill.
Comment 5e. [Employee Briefing] We are concerned about possible damage to
the NMFS seawater lines that cross Clam Bay when the thin cap material is
spread over this area. Can the thin cap material be installed without damage to
our existing seawater lines?
Response: The design contractor will coordinate closely with NMFS to
locate the lines and ensure adequate line protection during construction.
This may include doing the work at high tide.
Comment 5f. [EPA FMSD] Of primary concern during the actual remediation, is
maintaining continuous and uninterrupted access to the lab. Adequate
arrangement should be made for alternate access during the excavation in the
shore area, landfill operations, and cap installation. Access through the State
Park may provide an acceptable short-term alternative. The remedial design
should also include reconstruction of the road system leading to the lab, from
the Beach Drive entrance, through the landfill/work area, to the lab complex.
E\ ?n if actual excavation and landfill take place in areas outside the road
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corridor, we expect that heavy construction equipment will severely damage the
existing road.
Response: Continuous access to the Manchester Lab will be incorporated
into the remedial design. Negotiations with the Washington State
Department of Parks & Recreation are currently underway fora temporary
access road, in the event that one is needed. If the existing road is damaged
or demolished, it will be repaired or replaced in kind.
Comment Sg. [EPA Manchester Laboratory] It is very likely that the access road
will be heavily affected during construction activities and will be unavailable for
long periods of time. Since the laboratory will remain open during construction
activities, what provisions will be made for continuous access to the facility?
Response: Continuous access will be provided. If the existing road needs to
be closed or demolished as part of the cleanup project a temporary access
road will be constructed.
Comment 5h. [EPA OMP] During the remediation process, continuous access
must be maintained for the Manchester Lab. This may represent up to 200
vehicles per day. What alternatives will be considered if Washington State Park
denies permission for creation of a temporary access road through their
property?
Response: Continuous access to the Manchester Lab will be incorporated
into the remedial design. Negotiations with Washington State Department of
Parks & Recreation are currently underway for a temporary access road. In
any event, it is recognized that access options will be evaluated during the
design phase.
Comment 5i. [EPA Manchester Laboratory] The laboratory will continue full
operation during cleanup activities. Because of this we are concerned about the
potential contamination problems that may arise in our chemistry area,
particularly in the inorganic operation, when chemists are analyzing
environmental samples during the cleanup. Our laboratory is capable of very
low level analysis in the parts per trillion range. What steps will be taken to
insure that laboratory processes are not compromised during remedy
construction? Can a provision be made for stopping work if dust is generated
that cannot be controlled using wetting or misting methods?
Response: (See also response to Comment 2g.) The Corps will do everything
possible to minimize dust generation and migration. Performance standards
will be developed for control of dust. The performance standards will be
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developed with EPA Lab input and documented in the RAMP. Corrective
actions will be required, including stopping work if necessary, if these
performance standards are exceeded.
Comment 5j. [EPA FMSDJ It is not clear to FMSD that US Corps is fully aware of
the existing system of utility lines that cross the Manchester Annex Superfund
Site and considered them in the preferred alternative selection. As shown by
Attachment A, an old storm drain line travels through the proposed landfill area.
Also the water and sewer lines for the Manchester Laboratory are located to the
east of and parallel to the existing EPA security fence. The location of utility lines
should be considered during the design, construction, and post-construction
phases of any remediation, with particular attention to maintenance of
uninterrupted utility service during the remediation construction period.
Response: The Corps is aware of the utilities mentioned, and will work
closely with the EPA Manchester Laboratory and National Marine Fisheries
Service (NMFS) to minimize impacts to existing utility lines at the site. Utility
lines will be located and addressed in areas where remediation work will
take place during the design and construction phases of the project. If
interruptions or outages are unavoidable, the Corps will coordinate with the
EPA Lab and NMFS to minimize the impact to EPA's and NMFS's daily
operations.
Comment 5k. [EPA Manchester Laboratory] The pressurized water and sewer
lines for the laboratory are located to the east of and parallel to the existing EPA
security fence. Will these lines have to be moved as a part of the landfill capping
work? If the lines must be moved, what provisions will be made to insure these
services are available to the lab during construction activities?
Response: A relatively small quantity of landfilledsolid wastes are located
west of the utility corridor, on Manchester State Park property. Construction
of a cap over the utility corridor should be avoided. The likely solution (to
be determined during remedial design) will be to consolidate the wastes to
the east side of the corridor prior to capping them. An alternative solution
would be to relocate the utility corridor to outside the waste area. The
Corps will coordinate with EPA Lab if the design team determines that it is
necessary to move the lines. The Corps' goal will be to avoid any service
interruptions to the labs on site.
Comment 51. [EPA OMP] Will the existing water and sewer lines at the site risk
compromise due to the remediation? If so, what provisions have been
considered to ensure uninterrupted service to the lab?
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Response: See responses to Comments 5j and 5k.
ft Post-Remedial Operation, Maintenance, and Monitoring Issues
Comment 6a. [EPA FMSD] Although FMSO is, via a previous administrative
transfer, the owner of the Superfund site, FMSD recognizes that the U.S. Navy is
solely responsible for the contamination at the site that is currently undergoing
remediation pursuant to 40 CFR 300 under the Department of Defense (DOD)
Formerly Utilized Defense Sites (FUDS) Program. In light of this, OA expects that
the DOD FUDS Program and/or US Corps will also be responsible for post-
remediation activities associated with maintaining the integrity of the preferred
alternative, such as required operation and maintenance, long-term
environmental monitoring, future information reporting and review
requirements, maintenance of institutional controls, and any other unforeseen
remediation or environmental monitoring.
Response: The Corps will be responsible for operation and maintenance,
monitoring, and reporting in accordance with an approved O&M Plan and
the FUDS program requirements. The EPA Lab and other members of the
Manchester Work Croup will have input on the O&M Plan. Specific O&M
requirements, including length and extent will be determined after the
details of the remedy are determined and designed
Comment 6b. [EPA OMP] Once the remediation at the site is completed, I
believe that there will be a continuing need for operation and maintenance,
monitoring and recordkeeping, reporting, and possibly further remediation. This
could result in a significant resource consideration. I would like to see these
responsibilities clearly delineated for DOD or US Corps, whichever is
appropriate.
Response: The DOD is responsible for the cleanup costs under the Formerly
Used Defense Sites (FUDS) program. See response to Comment 6a.
Comment 6c. [EPA Manchester Laboratory] We believe the US Corps as the
Department of Defense (DOD) cleanup representative is responsible for any
long-term operations and maintenance (O&M), monitoring, and recordkeeping
that will be needed for this site forever or as long as the contaminated materials
remain on our property. If the proposed alternative selected includes leaving the
contaminated soils and sediments in the landfill, we request that the DOD
assume full responsibility for the long-term maintenance of the site as an adjunct
to their responsibilities for the cleanup.
Response: See response to Comments 6a.
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7. Coordination with Other Agencies/Programs
Comment 7a. [J. Schmidt Manchester State Park] His concern was the impact
the removal and disposal of material will have on the operation of the park. He
informed us that we would need clearances prior to any work being done. He
also requested that the following person be added to the mailing list for future
information:
Mr. Chris Regan
WA Dept of Parks & Recreation
7150 Clean Water Lane
PO Box 42650
Olympia, WA 98504-2650
Response: Appropriate clearances and/or leases will be obtained through
coordination with Washington Dept. of Parks & Recreation. Mr. Chris Regan
will be added to the mailing list.
Comment 7b. [EPA FMSDJ The remediation of the Manchester Laboratory site
represents a situation where the goals and objectives of the various components
of EPA may not be identical. For example, the goals and objective of EPA's
Superfund Program may differ from the goals and objectives of the Facilities
Management and Services Division (FMSD), as the title holder and owner of
EPA's real property assets; EPA Region 10's Office of Management Program
(OMP), as steward of the Manchester Laboratory; and EPA Region 10's Office of
Environmental Assessment (OEA), as the occupant and operator of EPA's
Manchester Laboratory. Therefore, future documents should specifically and
clearly identify the particular roles of each EPA program or office making a
decision, accepting a responsibility, or being made subject to restrictions in the
course of the remediation process. For example, the proposed plan does not
specify which EPA office is working with the U.S. Army Corps of Engineers to
design and manage remedial activities, who is responsible for CERCLA
enforcement, etc.
Response: In general when EPA is mentioned in memoranda, letters, and
documents, they refer to EPA in the Superfund Program role. Othenvise, the
specific offices will be distinguished if in such context or reference. In
general, when the documents refer to EPA as a property owner, the term
"EPA Lab " will be used. The Corps has requested that the offices
representing EPA as property owner designate one point-of-contact (POC)
to streamline the communication behveen EPA, FMSD, OMP, OEA, and the
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Corps. Having a primary EPA POC will allow the exchange of information to
- occur as efficiently as possible during design and construction.
Comment 7c. [EPA FMSD] As administrative controls or land use restrictions
contemplated in connection with the proposed remediation will impose
restrictions on FMSD, OEA, and OMP's use of the site and future expansion of
the Manchester Laboratory, FMSD, OEA, and OMP should be involved in
establishing any administrative controls or land use restrictions affecting EPA's
site and participate in the development of any long-term administrative controls
imposed on the landfill, curtain wall, and cap areas. Any proposed land use
restrictions should be clearly and officially communicated to FMSD, OEA, and
OMP.
Response: The Corps will coordinate with property "owners," including EPA,
regarding any long-term proposed land use restrictions at the site.
Comment 7d. [EPA FMSD] Obviously, design of the final remediation will
involve many decisions that affect the short-term and long-term functioning of
the Manchester Lab. FMSD, OEA, and OMP should be heavily involved as the
design of the Remedial Plan moves forward.
Response: EPA (as property owner) will receive draft copies of design
documents for review, and their input will be solicited through the
Manchester Work Croup. In addition, the Work Croup will be provided
periodic briefings on the design.
8. Other Issues
Comment 8a. [EPA FMSD) FMSD and OMP are currently working with the State
of Washington to obtain a renewal of the tidelands/bedlands lease connected
with the laboratory's pier. Any remediation plan should not contain any
provisions which would prevent FMSD and OMP from obtaining a renewal
lease, and should address any concerns the State of Washington has regarding
contamination of the tidelands/bedlands in this area of Clam Bay.
Response: Cleanup of the Clam Bay tidelands/bedlands has been
coordinated with the State of Washington Department of Natural Resources
(DNR), which is represented on the Manchester Work Croup. Since the
cleanup project will stop the source of contamination to the tidelands and
remediate a portion of the tidelands, it should not have any adverse impacts
on lease renewal, and may be beneficial in obtaining a renewed lease.
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Comment 8b. [EPA OMPJ My office is working with the Washington State
Department of Natural Resources to renew a lease for the tidelands and
bedlands beneath the laboratory's pier. Any remediation undertaken should
address any concerns DNR may have with regard to future contamination of the
tidelands/bedlands so that it does not preclude the issuance of a lease for the
tidelands/bedlands.
Response: See response to Comment 8a.
Comment 8c. [EPA Manchester Laboratory] When this site was listed on the
National Priorities List, the laboratory's internal hazardous waste generator
identification number was used in the preparation of the listing. The laboratory
generates hazardous waste as a part of our internal laboratory activities and this
waste stream and associated records must be maintained separately from the
Old Navy Dump-Manchester Annex Superfund site-generated waste. Hazardous
waste that was generated by the US Corps during the site investigation activities
and waste that will be shipped off site for disposal as a part of the Old Navy
Dump-Manchester Annex Site cleanup process must have a separate hazardous
waste generator identification number in order to maintain separate records and
appropriate responsibilities for this waste.
Response: The Corps has obtained and is using a separate hazardous waste
generator identification number for waste generated during investigative and
cleanup activities. Storage and disposition of wastes generated during
cleanup activities, and any reporting requirements, will be the responsibility
of the Corps.
The Corps feels the selected remedy provides a cost-effective program for
reducing site risk. In general, the public who have commented on the proposed
cleanup plan have been supportive.
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