PB99-964605
EPA541-R99-083
1999
EPA Superfund
Record of Decision:
Pacific Sound Resources (PSR) Site
Upland & Marine Sediments OUs
Seattle, WA
9/30/1999
-------
I
-------
Pacific Sound Resources (PSR)
Superfund Site
Seattle, Washington
Record of Decision
September 30, 1999
-------
-------
TABLE OF CONTENTS
Section
PART 1: THE DECLARATION 1
PART 2: THE DECISION SUMMARY 4
1. SITE NAME, LOCATION, AND BRIEF DESCRIPTION 4
2. SITE HISTORY AND ENFORCEMENT ACTIVITIES 4
2.1 Site History 4
2.2 Actions to Date . 4
2.3 Investigation History 5
2.4 Enforcement History 5
3. COMMUNITY PARTICIPATION 5
4. SCOPE AND ROLE OF RESPONSE ACTION 6
5. SITE CHARACTERISTICS 7
5.1 Conceptual Site Model 7
5.2 Upland Unit 9
5.2.1 Upland Overview 9
5.2.2 Upland Sources of Contamination : 9
5.2.3 Upland Sampling Strategy 10
5.2.4 Upland Nature and Extent of Contamination 11
5.3 Marine Sediments Unit 12
5.3.1 Marine Sediments Unit Overview 12
5.3.2 Marine Sediments Unit Sources of Contamination , 12
5.3.3 Marine Sediments Unit Sampling Strategy 13
5.3.4 Marine Sediments Unit Nature and Extent of Contamination 14
6. CURRENT AND POTENTIAL FUTURE SITE AND RESOURCE USES 16
6.1 Land Use 16
6.2 Groundwater Use 16
6.3 Surface Water Use . 16
7. SUMMARY OF SITE RISKS 17
7.1 Upland Unit Human Health Risks . 17
7.2 Marine Sediments Unit Human Health Risks 17
7.2.1 Identification of Chemicals of Concern 18
7.2.2 Exposure Assessment 18
7.2.3 Toxicity Assessment 19
7.2.4 Risk Characterization 19
7.2.5 Cancer Risks 21
7.2.6 Non-Cancer Risks 21
in
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
TABLE OF CONTENTS (Continued)
Section Pase
7.2.7 Discussion of Residual Risk Calculations 21
7.2.8 Uncertainties 21
7.3 Marine Sediments Unit Ecological Risks 22'
7.3.1 Identification of Chemicals of Concern... 22
7.3.2 Exposure Assessment 22
7.3.3 Ecological Effects Assessment 23
7.3.4 Risk Characterization 23
7.3.5 Uncertainties 24
7.4 Basis for Response Action 24
8. REMEDIATION OBJECTIVES 25
8.1 Upland Unit -. 25
8.2 Marine Sediments Unit 25
8.3 -Key Applicable or Relevant and Appropriate Requirements 26
8.3.1 Upland Unit 26
8.3.2 Marine Sediments Unit 27
9. DESCRIPTION OF ALTERNATIVES 28
9.1 Upland Unit 29
9.1.1 Completed Early Actions 29
9.1.2 Requirements to Ensure Upland Unit Actions Remain Protective 29
9.2 Marine Sediments Unit 30
9.2.1 Estimated Cleanup Areas and Volumes 30
9.2.2 Common Components of Alternatives 31
9.2.3 Disposal Sites 34
9.2.4 Description of the Alternatives 37
10. COMPARATIVE ANALYSIS OF ALTERNATIVES 42
10.1 Overall Protection of Human Health and the Environment 42
10.2 Compliance with Applicable or Relevant and Appropriate Requirements
(ARARs) 43
10.3 Long-Term Effectiveness and Permanence 43
10.4 Reduction in Toxicity, Mobility and Volume Through Treatment 43
10.5 Short-term Effectiveness 43
10.6 Implementability 44
10.7 Cost 44
10.8 State Acceptance 45
10.9 Community Acceptance 45
11. SELECTED REMEDY 45
11.1 Upland Unit 45
IV
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
TABLE OF CONTENTS (Continued)
Section Page
11.2 Marine Sediments Unit 46
11.3 Issues to be Addressed During the Design Phase of the Selected Remedy 47
11.4 Estimated Outcomes of the Selected Remedy 48
12. STATUTORY DETERMINATIONS 48
12.1 Protection of Human Health and the Environment: 48
12.2 Compliance with Applicable or Relevant and Appropriate Requirements
(ARARs) 49
12.2.1 Upland Unit ARARs 49
12.2.2 Marine Sediments Unit ARARs 49
12.3 Cost-Effectiveness.... 51
12.4 Utilization of Permanent Solutions and Alternative Treatment (or Resource
Recovery) Technologies to the Maximum Extent Practicable 52
12.5 Preference for Treatment as a Principal Element 52
12.6 Five-Year Review Requirements 52
12.7 Documentation of Significant Changes from Preferred Alternative of Proposed
Plan 52
PART 3: RESPONSIVENESS SUMMARY
-------
Pacific Sound Resources Superfund Site: Record of Decision
'000
LIST OF FIGURES
1 PSR Upland and Marine Sediments Unit Location Map
2 PSR Upland and Marine Sediments Unit Site Features
3 PSR Conceptual Model of Receptors and Exposure Pathways in the Marine Sediments
Unit Post-Upland Cleanup
4 PSR Marine Sediments Unit Shoreline Cap Area
5 PSR Marine Sediments Unit Phase 1, 2, and 3 Surface Sediment Chemical and Biological
Sampling Locations
6 PSR Marine Sediments Unit Phase 2 Subsurface Sediment Sampling Locations
7 PSR Marine Sediments Unit Surface Sediment Background Chemical and Triad
Sampling Locations
8 PSR Marine Sediments Unit Site and Background Fish Sampling Transects
9 PSR Marine Sediments Unit Surface Sediment PAH Exceedance Areas and Fill Contours
10 Approximate Location of Saltwater-Freshwater Interface PSR Superfund Site
11 PSR Marine Sediments Unit Modified Alternative 3b - Capping to CSLs
LIST OF TABLES
1 Summary of Surface Sediment Chemical and Biological Analyses
2 Summary of Shallow Subsurface Sediment Compositing Scheme and Chemical Analyses
3 Summary of Deep Subsurface Sediment Field and Laboratory Analyses
4 Summary of Clam and Fish Tissue Chemical Analyses
5 SMS and AET Chemical Screening Criteria for Sediment COCs
6 Surface Sediment Background Concentrations for Selected Contaminants
7 Summary Statistics for Surface Sediment COCs
8 Summary Statistics for Shallow Subsurface (0 to 20 feet bgs) Sediment COCs
9 Summary of Human Health Chemicals of Concern and Fish Tissue Exposure Point
Concentrations
VI
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
LIST OF TABLES (Continued)
10 Summary of Human Health Chemicals of Concern and Shellfish Tissue Exposure Point
Concentrations
11 Human Health Cancer Toxicity Data Summary
12 Human Health Non-Cancer Toxicity Data Summary
13 Risk Parameters
14 Human Health Risk Characterization Summary - Carcinogens
15 Human Health Risk Characterization Summary - Non-Carcinogens
16 Ecological Exposure Pathways of Concern
17 Occurrence, Distribution and Selection of Ecological Chemicals of Concern in Sediment
18 Occurrence, Distribution and Selection of Ecological Chemicals of Concern in Shellfish
19 Occurrence, Distribution and Selection of Ecological Chemicals of Concern in Fish
20 Alternate Concentration Limits
21 Alternative Summary
22 Comparison of Dredge Equipment
23 Estimated Schedule of Available Capping Material
24 Items To Be ConsideredPSR Site Sediment Remediation
25 Revised Costs Summary for MSU Remedial Alternatives
26 Cost Estimate Summary of Alternative 2 - Dredging to CSLs
27 Cost Estimate Summary of Alternative 3a - Capping to SQS
28 Modified Alternative 3b - Capping to CSLs - Capital Cost
29 Cost Estimate Summary of Alternative 3b - Capping to CSLs
30 Cost Estimate Summary of Alternative 4a - Fill Removal to SQS and Cap
31 Cost Estimate Summary of Alternative 4b - Fill Removal to CSLs and Cap
32 Cost Estimation for Groundwater Monitoring and DNAPL Collection
vn
-------
Pacific Sound Resources Superfund Site: Record of Decision
September 1999
LIST OF ACRONYMS AND ABBREVIATIONS
ACL Alternate Concentration Limit
AET ' Apparent Effects Threshold
ARAR Applicable or Relevant and Appropriate Requirement
AWQC Ambient Water Quality Criteria
B(a)P Benzo(a)pyrene
CAD Confined Aquatic Disposal
GDI Chronic Daily Intake
CERCLA Comprehensive Environmental Response Compensation and
Liability Act
CFR Code of Federal Regulation
CMS Crowley Marine Services
CND Confined Nearshore Disposal
COC Chemical of Concern
CSF Cancer Slope Factor
CSL Cleanup Screening Level
CSO Combined Sewer Overflow
CWA Clean Water Act
cy cubic yards
DMMP Dredged Material Management Program
DNAPL Dense Non-Aqueous Phase Liquid
DNR Washington State Department of Natural Resources
DRET Dredge Elutriate Test
Ecology Washington State Department of Ecology
EP Eddy Pump
EPA U.S. Environmental Protection Agency
ETI Environmental Toxicology International
FS Feasibility Study
HI Hazard Index
HP AH High Molecular Weight Polycyclic Aromatic Hydrocarbon
HQ Hazard Quotient
I&M Inspection and Maintenance
IRIS Integrated Risk Information System
LAET Lowest Apparent Effects Threshold
2LAET Second-Lowest Apparent Effects Threshold
LNAPL Light Non-Aqueous Phase Liquid
vin
-------
Pacific Sound Resources Superfund Site: Record of Decision
September 1999
LIST OF ACRONYMS AND ABBREVIATIONS
(Continued)
LPAH Low Molecular Weight Polycyclic Aromatic Hydrocarbon
MCL Maximum Contaminant Level
MCUL Minimum Cleanup Standard
MET Modified Elutriate Test
MLLW Mean Lower Low Water
MTCA Model Toxics Control Act
NAPL Non-Aqueous Phase Liquid
NCP National Contingency Plan
NOAA National Oceanic and Atmospheric Administration
NPDES National Pollution Discharge Elimination System
O&M Operation and Maintenance
OU Operable Unit
PAH Polycyclic Aromatic Hydrocarbon
PCB Polychlorinated Biphenyl
PCP Pentachlorophenol
PSDDA Puget Sound Dredged Disposal Analysis
PSR Pacific Sound Resources
PSR MSU Pacific Sound Resources Marine Sediments Unit
RAO Remedial Action Objective
RCRA Resource Conservation and Recovery Act
RETEC Remediation Technologies, Inc.
RfD Reference Dose
RI Remedial Investigation
RME Reasonable Maximally Exposed
ROD Record of Decision
ROV Remotely Operated Vehicle
SMS Sediment Management Standards
SQS Sediment Quality Standard
SVPS Sediment Vertical Profiling System
TCDD 2,3,7,8-tetrachlorodibenzo-p-dioxin
TCDF 2,3,7,8-tetrachlorodibenzo-furan
TEF Toxicity Equivalency Factor
TMDL Total Maximum Daily Load
TOC Total Organic Carbon
TSDF Treatment, Storage, and Disposal Facility
IX
-------
Pacific Sound Resources Super/and Site: Record of Decision September 1999
LIST OF ACRONYMS AND ABBREVIATIONS w
(Continued)
USGS U.S. Geological Survey
WES Waterway Experiment Station
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
PART 1: THE DECLARATION
Site Name and Location
The Pacific Sound Resources (PSR) facility, formerly known as the Wyckoff West
Seattle Wood Treating facility, was located on the south shore of Elliott Bay in Puget Sound at
2801 S.W. Florida Street, Seattle, Washington. The Environmental Protection Agency (EPA)
identification number is WAD009248287.
The site was divided into two operable units for investigation purposes; the Upland Unit
and the Marine Sediments Unit. This Record of Decision (ROD) addresses both Units.
The upland property was purchased by the Port of Seattle (Port) and included in their
redevelopment and expansion of an intermodal container terminal facility. The early actions
conducted under removal authority were implemented to control the site and prepare it for reuse.
The upland site is currently being utilized as part of the Port's intermodal yard.
Statement of Basis and Purpose
This decision document presents the Selected Remedy for the PSR site, which was
chosen in accordance with Comprehensive Environmental Response Compensation and Liability
Act (CERCLA), as amended, and to the extent practicable, the National Contingency Plan
(NCP). This decision is based on the Administrative Record file for this site.
The State of Washington Department of Ecology concurs with the Selected Remedy.
Assessment of Site
The response action selected in this ROD is necessary to protect the public health and
welfare, and the environment from imminent and substantial endangerment from actual or
threatened releases of hazardous substances into the environment.
Description of Selected Remedy
Upland Unit
The cleanup actions that have been completed to date include demolition of all on-site
structures, source material removal (highly contaminated soil and sludge), non-aqueous phase
liquid (NAPL) collection and disposal, and isolation of remaining contaminated soil and
groundwater with a low-permeability surface cap and subsurface slurry wall. These cleanup
actions have addressed the contaminated soil and on-going sources to the off-shore marine
environment. What was selected as early action is final action with the addition of the following:
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
Inspection and Maintenance (I&M) of the surface cap
Monitoring groundwater and collection of NAPL
Institutional controls for prohibiting groundwater use and restricting land use
Marine Sediments Unit
The Selected Remedy for the Marine Sediments Unit is:
Confinement through capping of contaminated marine sediments
Five feet of clean cap material will be placed in the intertidal area
Dredging of approximately 3,500 cubic yards of contaminated sediment to maintain
navigational access
Unused pilings will be removed
Institutional controls to prohibit large anchor use in capped area
Monitoring cap placement and cap performance
Statutory Determinations
The Selected Remedy is protective of human health and the environment, complies with
Federal and State requirements that are applicable or relevant and appropriate to the remedial
action, and is cost-effective. Treatment was evaluated for sediment cleanup, however was not
considered further for the following reasons: 1) there are currently no effective in situ treatments
(i.e., treating in place) for sediments covering a large area and subjected to significant flushing,
and 2) any ex situ treatment would require significant material handling (excavation, de-
watering, transport, and processing) and extreme cost (estimated at $40 million excluding
material handling). Thus, the Selected Remedy does not satisfy the statutory preference for
treatment as a principal element. Because this remedy will result in hazardous substances
remaining on-site above levels that allow for unlimited use and unrestricted exposure, a review
will be conducted within five years after initiation of remedial action to ensure that the remedy
continues to provide adequate protection of human health and the environment.
Data Certification Checklist
The following information is included in the Decision Summary section of this ROD.
Additional information can be found in the Administrative Record file for this site.
Chemicals of concern and their respective concentrations (see Tables 7 and 8)
Baseline risk represented by the chemicals of concern (see Section 7.2.4, Human Health
Risk Characterization)
Cleanup levels established for chemicals of concern and basis for the levels (see Table 5)
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
How source materials constituting principal threats are addressed (see Section 9.1.1,
Completed Early Actions)
Current and reasonable anticipated future land use assumptions and current and potential
future beneficial uses of groundwater used in the baseline risk assessment and ROD (see
Section 6, Current and Potential Future Site and Resource Uses)
Potential land and groundwater use that will be available at the site as a result of the
Selected Remedy (see Section 11.1, Upland Unit Selected Remedy)
Estimated capital, annual operation and maintenance (O&M), and total present worth costs;
discount rate; and the number of years over which the remedy cost estimates are projected
(see Tables 28 and 29 )
Key factors that led to selecting the remedy (see Section 10, Comparative Analysis of
Alternatives)
Authorizing Signature
Chuck Clarke Date
Regional Administrator
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
PART 2: THE DECISION SUMMARY
1. SITE NAME, LOCATION, AND BRIEF DESCRIPTION
The Pacific Sound Resources (PSR) facility, formerly known as the Wyckoff West
Seattle Wood Treating facility, was located on the south shore of Elliott Bay in Puget Sound at
2801 S.W. Florida Street, Seattle, Washington (see Figure 1). Wood-treating operations were
conducted at the site from 1909 to 1994. The wood-treating facility occupied approximately 25
upland acres. The southern portion of the facility (10 acres) was used primarily for treated wood
storage, and the northern portion of the facility (15 acres) was used for processing. All retorts,
product storage tanks and piping were located on the northern portion of the facility. The wood-
treating chemicals used at the PSR site included creosote, pentachlorophenol, and various
metals-based solutions. Soil, groundwater and off-shore marine sediments have all been
impacted by the facility's operation.
EPA is the lead agency for this site and the Washington State Department of Ecology
(Ecology) is the support agency involved. There are two sources of funding for cleanup of this
site; one is monies from a settlement involving the shareholders of the PSR Company (referred
to hereafter as the Company) in which an environmental trust was created to dedicate all the
assets of PSR at the time of the settlement to cleanup costs, and the other source is the
Superfund.
2. SITE HISTORY AND ENFORCEMENT ACTIVITIES
2.1 Site History
The wood-treating plant started as a pile-supported facility over the Duwamish River
estuary. The shoreline and intertidal area was filled in at various times throughout the last 100
years, and the facility was eventually entirely located on fill material that created an upland.
This in-filling resulted in the border between the upland and off-shore area being a steep riprap
bank. The site is located in an industrial area on the south shore of Elliott Bay.
2.2 Actions to Date
EPA conducted two phases of early cleanup actions on the upland portion of the site.
The first phase focused on site stabilization and demolition of on-site structures. The second
phase focused on controlling on going sources to Elliott Bay, addressing contaminated soil, and
preparing the site for reuse by the Port of Seattle (Port). During the first phase, in 1995, the
entire wood treatment facility was demolished and approximately 4,000 cubic yards of highly
contaminated soil and process sludge were removed from the site. During the second phase,
which began in 1996, a subsurface physical containment barrier (slurry wall) was installed to
prevent light non-aqueous phase liquid (LNAPL) migration to Elliott Bay, and to reduce the
influence of tidal fluctuation at the site. The slurry wall is 1,200 feet in length and it extends
from the ground surface to a depth that averages 40 feet below ground surface. An LNAPL
recovery trench was installed in conjunction with the barrier wall to intercept any LNAPL. In
-------
Pacific Sound Resources Superfund Site: Record of Decision . September 1999
addition, a low-permeability asphalt cap was constructed over a layer of clean fill placed at the
site. This cap was designed to prevent direct soil exposure to on-site workers, prevent runoff of
contaminated soil to Elliott Bay, and minimize infiltration of storm water to groundwater. The
cap was completed in 1998.
Other early actions taken at the site include clean out of the Longfellow Creek overflow
channel and marine outfall (along the western border of the site - see Figure 2), and collection
and disposal of the dense non-aqueous phase liquid (DNAPL) that accumulates in on-site
monitoring wells. Twenty-five cubic yards of PCB contaminated sediments were removed from
the Longfellow Creek outfall area by the Port as part of their terminal development work, and
approximately 1,500 gallons of DNAPL has been recovered from on-site wells and treated
through incineration over the last three years.
2.3 Investigation History
Numerous investigations were conducted at this site prior to the initiation of the RI/FS.
The Wyckoff Company, EPA, and Ecology all investigated various aspects of the site between
1983 and 1992 under regulatory authority other than Comprehensive Environmental Response
Compensation and Liability Act (CERCLA). While work was conducted under Resource
Recovery and Conservation Act (RCRA) authority, the site was not considered a treatment,
storage and disposal facility (TSDF). Company relations with EPA and Ecology were
contentious through the 1980s, and included a federal criminal prosecution for violations of the
Clean Water Act and RCRA.
The Upland Unit RI/FS began in 1994 and focused on groundwater, including non-
aqueous phase liquid (NAPL) contamination. The Marine Sediments Unit RI/FS began in 1996
and focused on marine sediment contamination. Human health and ecological risk assessments
were conducted for both the upland and off-shore areas.
2.4 Enforcement History
The PSR site was added to the National Priorities List in May 1994. A settlement with
the Company was embodied in a Consent Decree entered in Federal District Court in August
1994. The Decree creates the PSR Environmental Trust into which the heirs of the Wyckoff
Company founders, owners and operators placed all ownership rights and shares in the Company
to allow the Trust to maximize liquidation of all company assets, including nonwood-treating
holdings, for the benefit of the environment. The beneficiaries of the Trust are the United States
Department of Interior, National Oceanic and Atmospheric Administration (NOAA) of the
Department of Commerce, and the Suquamish and Muckleshoot Tribes, as Natural Resource
Trustees, as well as EPA for reimbursement of CERCLA remedial costs.
3. COMMUNITY PARTICIPATION
EPA, Ecology, and the Port have kept the public aware and updated with respect to
cleanup and redevelopment progress at the site. Community participation in this process has
included personal interviews, public signs, fact sheets, newspaper notices, and pubic comment on
-------
Pacific Sound Resources Super/and Site: Record of Decision September 1999
previous cleanup actions. In addition, the Port has worked extensively with the local community
regarding its redevelopment project to address traffic, lighting, noise, and public access concerns.
The RI/FS reports and Proposed Plan for the PSR site were made available to the public
in April 1999. They can be found in the Administrative Record file that is maintained at the U.S.
EPA Records Center on the seventh floor of 1200 Sixth Avenue in Seattle. The notice of the
availability of these two documents was published in the Seattle Times on April 21, 1999. A
public comment period was held from April 15 to May 15, 1999. EPA's response to comments
received during this period is included in the Responsiveness Summary, which is part of this
Record of Decision (ROD).
4. SCOPE AND ROLE OF RESPONSE ACTION
The cleanup actions previously completed at this site removed the ongoing source of
subsurface contamination and the highly contaminated material (soil and sludge) above the water
table that was the source of increasing contaminant volume in the subsurface and the primary
driver for contaminant migration. These actions also eliminated the threat of contact with
contaminated soil through construction of a barrier, and reduced contaminated groundwater
impacts to Elliott Bay through placement of a subsurface wall. While contamination will remain
on-site, its potential to adversely impact human health and the environment has been mitigated
by isolating it and stopping its continued migration.
The PSR facility did not identify itself as a Treatment, Storage and Disposal Facility
(TSDF) pursuant to the RCRA procedures while it was operating. No determination was made
through a compliance action that the wood-treating operation was a TSDF. As such, the facility
was not subject to RCRA storage closure requirements. However, the facility was identified as a
hazardous waste generator (Resource Conservation and Recovery Identification System number
WAD009248287), and wastes taken from the site as part of the removal actions were sent to a
RCRA-permitted land disposal facility. The Land Disposal Restriction treatment standards had
not been established for wood-treating waste at the time the removal actions were conducted.
The groundwater investigation indicates that groundwater does contain site-related
contaminants, however the concentration in groundwater at the point where it enters Elliott Bay
(the sediment/surface water interface or "mudline") is so low that it is not a source of
contamination to either the bay (surface water) or the marine sediment. While this ROD requires
ongoing monitoring of groundwater, inspection and maintenance of the upland cap, and
institutional controls for the Upland Unit to assure the efficacy and integrity of previously
implemented removals, the Selected Remedy contained herein focuses on contaminated marine
sediment.
The Marine Sediments Unit encompasses both intertidal and subtidal areas. The
intertidal area is approximately two acres in size and is only emergent during lower tides.
Specifically, the subtidal area consists of two beach areas that emerge between the piers. These
small beaches are referred to as pocket beaches. In addition, the intertidal area includes a thin
beach along the toe of the riprap bank at extremely low tides. The subtidal area ranges in depth
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
from intertidal to greater than 200 feet, with approximately 35 percent of the area having a slope
of 18 to 21 percent.
This ROD contains the final cleanup actions for this site.
5. SITE CHARACTERISTICS
This section summarizes information obtained as part of RI/FS activities at the site. It
includes a description of the conceptual site model on which all investigations, the risk
assessment, and response actions are based. In addition, this section presents sources of
contamination, subsequent sampling strategies, and documented types of contamination and
affected media. The conceptual site model is presented for the entire site; all other information is
presented by operable unit. Figure 2 depicts current site features.
5.1 Conceptual Site Model
The Conceptual Site Model depicting contaminant migration for the Upland Unit and
Marine Sediments Unit of the PSR site is presented in Figure 3. The primary source of
contamination in the Upland Unit (soil and groundwater) was the daily operation of the wood-
treating facility including spills, leaks and storage of wood-treatment products. Based on soil
borings taken from the Upland Unit, it appears that releases of wood-treatment products occurred
throughout the facility's lifetime. Borings reveal layers of contamination that indicate releases
occurred both before and after the various filling episodes that turned the originally pile-
supported facility into an upland area. Due to the nature of the material (primarily creosote and
an oil carrier containing other wood-treatment chemicals), the volume of released material
increased with time and seeped down into the soil, encountered groundwater, and separated into
a light and dense phase. The lighter phase floats on the groundwater and the denser (or heavier)
phase sinks through the soil formation. The floating material is referred to as light non-aqueous
phase liquid (LNAPL) and the sinking material is referred to as dense non-aqueous phase liquid
(DNAPL). The NAPL associated with the PSR site is detected in the environment as polycyclic
aromatic hydrocarbons (PAHs). Creosote is primarily made up of PAHs.
The LNAPL followed the flow pathway of the groundwater (i.e., discharged to Elliott
Bay). Prior to the placement of the slurry wall, LNAPL was seen as oily seepage at the shoreline
of the facility. DNAPL followed the path of least resistance (which is downward, due to gravity;
however, the path has a lateral component due to grain size variation). Free-phase NAPL (both
light or dense) is mobile and able to flow. Residual NAPL is the material that is left behind after
the free-phase NAPL (either light or dense) has moved through (i.e., NAPL caught in the soil
pore spaces). NAPL stringers result when the majority of the mass of NAPL had been spent and
the remainder continues to "trickle" through the formation. Residual NAPL will often be
detected in the form of stingers, indicating that a larger NAPL mass exists in the area.
Consequently, in addition to the layers of contamination created by releases to the soil surface
both before and after the filling in of the upland area, upland soil borings indicate NAPL
contamination as deep as the deepest borings taken (100 feet below ground surface).
-------
Pacific Sound Resources Svperfund Site: Record of Decision September 1999
Passive NAPL collection trials were conducted during the Upland Unit RI and
determined that free-phase NAPL recharge volumes (i.e., how much material flowed back into a
well after collection) decreased at all collection locations over time. Since the collection
locations were chosen based on soil borings and subsurface detection methods indicating higher
concentrations of NAPL, it is determined that free-phase NAPL exists in thin layers or stringers
at this site, rather than pools.
Of primary concern when initiating the RI/FS for this site, was whether the contamination
associated with the upland facility was the source of the contamination in the marine sediment.
Specifically, if the upland facility were the primary source, eliminating or controlling that source
would be necessary prior to active sediment remediation. As the RI results indicated and Figure
3 depicts, the source of contamination to the marine sediment is not the upland NAPL, rather it
was surface releases of wood-treatment contaminants to the off-shore environment. Off-shore
sediment borings indicate a clear demarcation between native material (i.e., a clean estuarine
formation) and the contaminated material above it. To distinguish between the native and
contaminated material, the contaminated material is referred to as the Marine Sediments Unit Fill
Area throughout this ROD. While the borings reveal a surface source of contamination to the
Marine Sediments Unit rather than a lateral source, they also reveal stringers of NAPL far below
the sediment surface.
Current sediment contamination is the primary result of the following historical releases:
Releases of used or waste creosote and associated wood preservative carrier oil to surface
water from the wood-treatment operations. This release pathway contaminated sediments
in the southwestern portion of Elliott Bay and represents the primary source of
contamination to the Marine Sediments Unit.
Releases of process wastewater and contaminated stormwater from the Upland Unit to
Elliott Bay. These releases contributed to sediment contamination as a result of the
partitioning of dissolved contaminants to sediment.
Erosion of contaminated soil by surface water runoff to Elliott Bay. This pathway
contributed minor amounts of contamination to the marine sediments.
Historical downward and lateral migration of free-phase creosote and oil via preferential
flow pathways (e.g., sand layers in subsurface sediment) towards Elliott Bay. While
NAPL migration has been effectively stopped through implementation of early actions,
the NAPL that remains in place continues to dissolve into groundwater.
Transport of contaminated groundwater from the Upland Unit to Elliott Bay is an
ongoing process, however the concentration of contaminants in groundwater is not resulting in
injury to Elliott Bay (i.e., surface water is not being impacted). Installation of the slurry wall
near the shoreline has nearly eliminated migration of contaminated shallow groundwater (less
than 40 feet below ground surface) to Elliott Bay and completely stopped LNAPL seepage at the
shoreline. However, modeling suggests that deeper groundwater may contribute to sediment
contamination via dissolved contaminant advection and dispersion (i.e., the slow dissolution of
NAPL into groundwater and the consequent movement of groundwater to the sediments of
Elliott Bay). Based on modeling results, this could result in recontamination in a specific area of
-------
Pacific Sound Resources Superfitnd Site: Record of Decision September 1999
the Marine Sediments Unit referred to as the Intermediate Groundwater Discharge Zone (see
Figure 4). It is important to note that this potential for recontamination is based on modeling that
used conservative assumptions and overestimates the amount of contamination that would
dissolve in groundwater and later be bound to sediments.
The conceptual site model is primarily based on the interaction of wood-treatment
chemicals in the environment. However, the Marine Sediments Unit RJ also found PCB
contamination from and in the local vicinity of the Longfellow Creek outfall (not from the PSR
site). Historically, Longfellow Creek flowed along the western boundary of the site, but was
rerouted to discharge to the West Waterway of the Duwamish River. The original creek bed was
piped and serves as a stormwater and creek overflow channel. The Longfellow Creek overflow
discharges just west of the Upland Unit into the Marine Sediments Unit.
5.2 Upland Unit
5.2.1 Upland Overview
The Upland Unit, consisting of the former wood-treating facility, occupies approximately
25 acres. The Upland Unit is bounded to the north by Elliott Bay and by the Port of Seattle's
newly constructed intermodal rail yard and container shipping terminal on all other sides. The
West Waterway of the Duwamish River, which discharges to Elliott Bay, borders the terminal to
the east. An active bulk materials shipping facility [Crowley Marine Services (CMS)], lies
directly west of the container terminal (and the former PSR Upland Unit).
The wood-treating plant evolved over time from a pile-supported facility over water to a
facility constructed on fill. The upland site is currently situated on approximately 20 to 45 feet
of fill material that was intermittently placed over a 50-year span on what was the Duwamish
River estuary. Fill materials generally consist of dredged sediments or excavated soils, sawdust,
and construction debris. Wood and concrete bulkheads constructed to contain the fill material, as
well as control erosion and protect equipment from marine tides, are still buried beneath the site.
No surface water bodies are located within the Upland Unit, although localized flooding had
been documented during periods of heavy rainfall at the wood-treating facility.
Currently, the Upland Unit is covered with a low-permeability asphalt cap that includes
an underground storm drainage and utility system, railroad tracks, and a maintenance and repair
building associated with the intermodal rail yard. The northern-most shoreline was developed as
a public viewing area and consists of lawns, landscaping, playscapes, concrete pathways, public
rest rooms and outdoor showers, a viewing tower and public access pier. Fencing and fishing
exclusion screens border the shoreline and pier and restrict access to the intertidal area..
5.2.2 Upland Sources of Contamination
Early actions at the site removed much of the process-related source materials including
leaking storage tanks and 3,840 tons of process sludges and creosote-saturated soils. Material
remaining on-site includes contaminated soil and groundwater, limited LNAPL, and widespread
DNAPL. Additional actions at the site have contained the majority of the on-site contaminated
-------
Pacific Sound Resources Superfitnd Site: Record of Decision September 1999
media. DNAPL occurs on the site in both free (i.e., mobile) and residual phases. The free-phase
DNAPL appears to be distributed throughout the site rather than in discreet accumulations or
pools.
Some DNAPL'has been measured in the shoreline wells on the western portion of the
site. However, continued monitoring of those wells and pumping of all on-site wells containing
measurable quantities of NAPL has reduced the occurrence and volume of DNAPL in these
wells. DNAPL was also detected at some of the deepest stations sampled under the upland
process area (i.e., 100 feet below ground surface) and extends as stringers downward and toward
Elliott Bay.
Evaluations made during the RI concluded that the stringers of creosote extending
underneath Elliott Bay (approximately 80 feet below the sediment surface) are highly unlikely to
seep up and out of the sediment and into Elliott Bay. This conclusion was based, in part, on the
characteristics of the underlying stratigraphy (layers of estuarine sediment parallel the sloping
bottom surface), and continued gravitational pull (DNAPL does not flow uphill). However, the
residual or free-phase DNAPL will contribute to dissolved groundwater contamination as
groundwater moves past the DNAPL mass.
The majority of the contamination associated with the Upland Unit has been contained
behind and below the barrier wall and cap. The relatively small percentage of NAPL that has not
been isolated by the wall and cap can act as a source to groundwater contamination.
5.2.3 Upland Sampling Strategy
The Upland Unit RI/FS began in 1994 and focused on establishing the nature and extent
of soil and groundwater contamination and the distribution of non-aqueous phase liquids
(NAPLs). Evidence of staining and chemical analyses of soil from over 215 borings were used
to establish the extent of contamination in soil and confirm the presence of NAPLs. Numerous
groundwater samples were analyzed for chemicals of concern and measurements of NAPL
thickness and recovery were made in all affected wells. Tidal studies were conducted to examine
the effectiveness of the subsurface wall in minimizing the influence marine water of Elliott Bay
on groundwater flows at the site. Geological investigations examined the subsurface stratigraphy
and a laser-induced fluorescence sampling device was used to establish areas of free-phase or
recoverable DNAPL in the northern portion of the site.
Based on the results of subsurface investigations, recovery wells were installed in the
areas of free-phase NAPL accumulations. A test was conducted to determine how much NAPL
could be collected by encouraging flow into on-site wells through varying the interval between
collection events. In situ flushing and biological treatability studies for groundwater were also
conducted to determine their effectiveness at the PSR site. In addition, the upland investigation
included an assessment of the performance of the barrier wall.
10
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
5.2.4 Upland Nature and Extent of Contamination
As stated previously, wood-treating chemicals used at the facility included creosote
(primarily composed of PAHs), pentachlorophenol (PCP), and various metal (arsenic, chromium,
copper and zinc)-based solutions. Facility operations, including spills, leaks, and storage of
wood-treatment products, were primarily responsible for upland soil and groundwater
contamination. Based on work prior to the RI (RETEC et al., 1994, Current Conditions
Report), it was established that the majority of the contamination occurred in the northern
portion of the site in areas associated with the wood-processing and treated wood storage areas.
During the RI and prior to placement of the subsurface wall, PAHs were detected in the
majority of the wells sampled, including shoreline wells. DNAPLs were found in several wells,
including two shoreline well clusters along the western shoreline. The mass of NAPL that may
be present beneath the site in both soils and groundwater is estimated at over 12.2 million
pounds. About 550,000 Ibs. is estimated to be present as free-phase NAPL; the remainder exists
as residual NAPL. The majority of the NAPLs occur at depths greater than 8 ft below ground
surface (where the groundwater table occurs). The Upland RI/FS estimates that 96 percent of the
NAPL associated with the PSR site is either behind or below the subsurface slurry wall.
Groundwater Contamination
The hydrogeology of the Upland Unit is characterized by a single unconfined shallow
aquifer within the fill and alluvium. This aquifer, which is contaminated by significant
concentrations of creosote constituents in both dissolved and DNAPL forms, has been
determined to be non-potable by the Washington State Department of Ecology. EPA's
groundwater classification evaluation has resulted in this aquifer being classified as both Class
lib and Class III (see following discussion under Key Applicable or Relevant and Appropriate
Requirements).
Groundwater recharge in the area occurs as a result of stormwater infiltration from the
site, as well as from upland areas to the south. However, onsite stormwater infiltration has been
precluded by the construction of the asphalt cap covering the upland site. Groundwater below
the Upland Unit is influenced by infiltration and tidal fluctuation of estuarine waters from Elliott
Bay, but these influences have been significantly reduced by the slurry wall.
The overall movement of groundwater in the vicinity of the site is in a northerly direction
toward Elliott Bay. Groundwater discharge to the bay occurs via shoreline diffuse flow through
nearshore sediments. To evaluate the potential impact of groundwater transport on sediment
quality in the Marine Sediments Unit, groundwater fate and transport modeling was conducted as
part of both the Upland and Marine Sediments Unit remedial investigations. The results of the
upland modeling effort, which focused on water quality at the potential point of discharge,
indicates that groundwater meets cleanup goals at the mudline (i.e., the point where groundwater
enters Elliott Bay).
For the Marine Sediments Unit modeling effort, BIOSCREEN (an EPA fate and transport
model) was used to determine whether the existing groundwater quality conditions have the
II
-------
Pacific Sound Resources Super/and Site: Record of Decision September 1999
potential to contaminate a clean sediment cap following site remediation (i.e., following
placement of a 3-foot thick cap over existing contaminated sediment). The BIOSCREEN model
results predicted that sediment concentrations for two individual PAHs would exceed 2LAET
values after 10 years in the intermediate groundwater discharge zone (-25 to -50 feet MLLW
along the west-central'shoreline). It was determined that this potential for sediment
recontamination is primarily associated with groundwater flowing from the west-central portion
of the upland site. However, assumptions used in the model were very conservative and did not
account for any natural attenuation that may occur and assumed 100 percent of the contaminant
mass transported by groundwater would be retained in the sediments.
5.3 Marine Sediments Unit
53.1 Marine Sediments Unit Overview
The investigation of the Marine Sediments Unit encompassed approximately 200 acres of
Elliott Bay and 1,600 feet of shoreline adjacent to and offshore of the Upland Unit. The
shoreline consists primarily of rock and riprap. Three wooden piers, which form the Main and
West slips, extend into the central and western portions of the Marine Sediments Unit. As part
of the Port's redevelopment of the site, the western-most pier has been repaired for use as a
public viewing platform. The two remaining piers will be removed to facilitate cleanup of the
Marine Sediments Unit. Two small pocket beaches exist between the piers and adjacent to
Crowley Marine Services; a thin band of a muddy sand beach forms along the toe of the
riprapped banks on more extreme tides.
Bottom depths within the Marine Sediments Unit vary from intertidal to over 200 feet
deep, with a generally steeply sloped configuration ranging from 6 to 20 (or greater) percent
slope. The steepest slopes are nearshore, and slopes gradually decrease with increasing distance
offshore.
5.3.2 Marine Sediments Unit Sources of Contamination
Sediment contamination in the Marine Sediments Unit is the result of releases of wood-
treating preservatives during the treatment and storage process, or release of process wastewater,
from the Upland Unit to Elliott Bay. Downward and lateral migration of free-phase NAPLs,
transport of contaminated groundwater, and erosion of contaminated soils by stormwater runoff
from the Upland Unit represent other historical sources and transport pathways to the Marine
Sediments Unit. In addition, the Longfellow Creek outfall contributed PCB contamination to the
Marine Sediments Unit, and mercury contamination appears to have migrated from a source to
the east of the site.
As a result of cleanup actions in the Upland Unit, there are only three likely contaminant
migration pathways remaining: transport of dissolved contaminants via groundwater with
subsequent partitioning to sediment, dissolution of sediment-bound contaminants to the waters of
Elliott Bay, and longshore or downslope migration of contaminated surface sediment in the
Marine Sediments Unit. The transport of free- and dissolved-phase NAPL in shallow
groundwater to Elliott Bay has been inhibited by the slurry wall and LNAPL recovery trench that
12
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
were constructed as part of the upland source control activities. However, some DNAPL is
present seaward of and deeper than the slurry wall, constituting an ongoing, however minor
source to the bay. Modeling conducted as part of the Marine Sediments Unit RI suggested that
deep groundwater discharging from the western portion of the site may have the potential to
recontaminate sediment in the intermediate groundwater discharge zone offshore of Crowley
Marine Services. However, assumptions used in the model were very conservative, did not
account for any natural attenuation that may occur, and assumed 100 percent of the contaminant
mass transported by groundwater would be retained in the sediments.
5.3.3 Marine Sediments Unit Sampling Strategy
The RI sampling activities in the Marine Sediments Unit were conducted in three phases
that extended from April 1996 to July 1997 and included the following:
Subtidal surface and subsurface sediment sampling and chemical and physical analysis to
determine the nature and extent of contamination. A limited number of subsurface
samples were also analyzed for various engineering parameters to support future design
evaluations.
Fish and shellfish tissue sampling and chemical and physical analysis to evaluate
biological uptake and potential fish and human health risks.
Laboratory bioassays to evaluate potential acute biological effects of the observed
contamination on marine invertebrates.
Benthic community evaluations to assess potential chronic biological effects
The RI surface (0 to 10 cm) sediment sampling was conducted during three phases from
April 1996 to July 1997. Each successive phase was required to fully delineate the outermost
boundaries of Marine Sediments Unit surface sediment contamination. In addition to submitting
samples for laboratory chemical and physical analyses, field immunoassays and visual
observations were conducted at selected locations to assist in the delineation of contaminant
extent. In total, 109 of 161 stations sampled are represented by laboratory data, which were
subsequently compared with the sediment effects-based (or background) screening values.
Figure 5 depicts the surface sediment sampling locations and Table 1 summarizes the sample
analyses.
Subsurface sediment sampling was conducted during the second phase of the RI sampling
activities, from September through November 1996. Shallow subsurface (0 to 20 feet below
mudline) sediment cores were collected from 17 stations and generally composited in 4-foot
intervals. Of the 77 resulting core samples (including duplicates), 65 were submitted for
physical and chemical analyses, including PAHs. Select shallow core intervals were also
composited and submitted for modified elutriate testing (MET) and dredge elutriate testing
(DRET), to initially determine remedial design options. The deep subsurface (0 to 96 feet below
mudline) sediment cores were collected from three locations and were continuously sampled for
stratigraphic interpretations at 2-foot intervals. Select intervals were also subjected to field
analyses, which including long-wave UV screening and immunoassays, or were submitted for
laboratory physical testing (e.g., engineering parameters). Figure 6 depicts the subsurface
13
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
sediment sampling locations and tables 2 and 3 summarize the shallow and deep-core sample
analyses, respectively.
The biological sampling conducted in support of the human health and ecological risk
assessments occurred during the second phase of the RI. Surface sediment from nine Marine
Sediments Unit and two Elliott Bay background stations were collected for laboratory acute
bioassays (using amphipods and sand dollar larvae), benthic community enumeration and
identification, a laboratory bioaccumulation test (using the clam Macoma nasuta), and chemical
and physical analyses (see Figures 5 and 7 ). In addition, fish (English sole) tissues were
sampled from two transects offshore of the MSU and two background transects in Elliott Bay
(see Figure 8). The clam tissues were analyzed for bioaccumulative Chemicals of Concern
(COCs), including PAHs and dioxins and furans. The fish tissues were also analyzed for these
contaminants, with the exception of PAHs, which are readily metabolized by these receptors and
were thus not likely to be detected. Table 4 provides a summary of the clam and fish tissue
sample analyses.
5.3.4 Marine Sediments Unit Nature and Extent of Contamination
Sediment Contamination
Sediment problem areas and chemicals were determined based on exceedances of
available effects-based screening values, or, where not available, Elliott Bay background
concentrations established as part of the RI sampling program. Specifically, sediment chemical
data were compared with effects-based Washington State Sediment Management Standards
(SMS; WAC 173-204) or Puget Sound Apparent Effects Threshold (AET) values (see Table 5).
The Washington State Sediment Management Standards provides two sets of effects-
based chemical criteria for Puget Sound sediment. Sediment Quality Standards (SQS),
established as long-term cleanup goals, correspond to a sediment quality below which no adverse
effects on biological resources will result. Cleanup Screening Levels (CSL) are less stringent
standards that correspond to minor adverse effects thresholds for biological resources; they are
typically used to determine if remediation is required in a specific area. Sediment chemical data
were compared to both of these criteria.
For comparisons to the SMS, all nonionic/nonpolar organic chemicals were normalized to
percent total organic carbon (TOC) content. However, if station-specific TOC content was
outside of the range considered appropriate for normalization, (i.e., less than 0.5 or greater that
4.0 percent), then the nonionic/nonpolar organics chemical results were compared with Puget
Sound AETs. The AETs represent the chemical concentrations above which deleterious
biological effects have been demonstrated to always occur. The lowest AET (LAET) was used
as the equivalent of the SQS, and the second-lowest AET (2LAET) was used in place of the CSL
where TOC exceeded Ecology guidelines.
Because no sediment criteria for the protection of human health have been promulgated
to date, delineation of those areas of concern for human health was based on the SMS chemical
criteria. Within those areas defined by the SQS or CSL, standard risk assessment techniques
14
-------
Pacific Sound Resources Super fund Site: Record of Decision September 1999
were used to evaluate threats to peopJe eating seafood caught from the site (see Section 7,
Summary of Site Risks).
In addition, regulatory sediment effects-based screening values were not available for
dioxins and furans. The extent of contamination by these compounds was therefore evaluated by
comparison to Elliott Bay background concentrations that were established as part of the RI
sampling program (see Table 6).
Chemicals found to exceed effects-based or background screening values in surface and
subsurface sediment included low molecular weight PAHs (LPAHs), high molecular weight
PAHs (HPAHs), phenolic compounds, dibenzofuran, dioxins and furans, PCBs, and mercury.
Tables 7 and 8 summarize the frequency of detection, minimum and maximum values and
number of exceedances of criteria for surface and subsurface samples. Of the chemicals
exceeding screening values, PAHs were identified as of primary concern based on their
widespread distribution and magnitude of exceedance. Of the more than 100 samples analyzed,
concentrations of total LPAHs exceeded SQS or LAET screening values in nearly 60 percent of
the surface samples and approximately half of the subsurface samples. The CSL or 2LAET
screening criteria for total LPAHs were also exceeded in nearly one-third of the surface samples
and nearly 40 percent of the subsurface samples. Two individual LPAHs, acenaphthene and
fluorene, exceeded their respective criteria even more frequently in both surface and subsurface
samples. Concentrations of individual HPAHs and total HPAHs were typically lower than
LPAHs, relative to their respective screening criteria (i.e., fewer HP AH screening criteria
exceedances were observed, compared to the LPAHs). In general, concentrations of PAHs
tended to decrease with distance offshore of the Upland Unit.
The depth of contamination is not homogeneous in the Marine Sediments Unit. PAHs
tended to have a subsurface maxima within the top 4 feet of sediment, although concentrations in
excess of screening criteria were found up to 20 ft below mudline. A study of substrate
characteristics conducted by the U.S. Geological Survey (USGS) mapped areas of significant
accumulation of non-native sediment or fill materials using side-scan sonar techniques. These
fill areas correlated well with occurrences of subsurface contamination measured during the RI.
According to the USGS, these fill materials range from about 20 feet thick near the shoreline to
about 3 feet thick at the furthest boundary of the fill footprint (approximately 700 feet north of
the main pier). However, the depth of contamination is not well correlated with distance from
shore, possibly reflecting separate release events from the facility.
Other contaminants of concern, including phenolic compounds, dibenzofuran, and
dioxins and furans, tended to occur with PAHs and were similarly present at highest
concentrations at nearshore locations. Elevated concentrations of mercury and PCBs (relative to
SMS screening criteria) appeared to be more localized and not related to sources from the
Upland Unit, as they occurred primarily east (mercury) and west (PCBs) of the Upland Unit.
Because PAHs represent the primary contaminant of concern in the surface sediment, the
results of the comparisons of these surface sediment data with SMS and AET screening values
were used to define the areal extent of contamination in the Marine Sediments Unit (see
Figure 9). Overall, approximately 100 acres and 1,000,000 cubic yards of sediment are
15
-------
Pacific Sound Resources Superfund Site: Record of Decision September J999
contaminated with PAHs at concentrations in excess of the lower (SQS/LAET) sediment
screening values. When compared with the upper sediment screening value (CSL/2LAET), this
area is reduced to approximately 50 acres and 500,000 cubic yards of contaminated material.
The results of the laboratory toxicity tests and the benthic community evaluations are
discussed in Section 7 of this ROD under Ecological Risk Assessment, while the fish and clam
tissue results are discussed in Section 7 under Human Health Risk Assessment.
6. CURRENT AND POTENTIAL FUTURE SITE AND RESOURCE USES
6.1 Land Use
The current and future land use associated with the upland portion of the site is use as
part of the Port of Seattle's intermodal terminal. As such, the site will primarily be used as an
industrial property. The Port has leased the property to a container transport company (a 30-year
lease), and it is anticipated this property will continue to be used for container storage and
transfer into the foreseeable future. The property located to the south and east of the site is also
part of the intermodal yard. The property to the west of the PSR site is utilized as a barge
transport facility for bulk materials, and the site is bordered to the north by Elliott Bay. A small
portion of the upland area of the site immediately adjacent to the shoreline has been developed
for public use, which includes an observation tower and a scenic public walkway. Access to the
shoreline itself has been prohibited and is physically inaccessible from the Upland Unit through
the use of fencing.
6.2 Groundwater Use
The groundwater associated with this site is not currently being utilized, nor should it be
utilized for any purpose in the future. The State Department of Ecology has made a
determination that groundwater beneath the PSR site is not suitable as a potable water supply,
and no wells will be permitted. EPA's groundwater classification evaluation concurs with this
determination. Further, EPA has determined that the groundwater associated with PSR meets the
criteria necessary to set alternate concentration limits for the site-related contaminants of
concern.
6.3 Surface Water Use
The PSR site is located in the southwestern portion of Elliott Bay, a deep, cold-water
embayment located in east-central Puget Sound. Elliott Bay has been extensively developed for
urban, port, and industrial land uses. While the intertidal/shoreline area is not accessible from
the PSR site, there are a couple of beach areas exposed during low tides, and include mud- and
sand-flats, as well as pilings and riprap. The Marine Sediments Unit is located in a transition
zone between the estuarine environment of the Duwamish River and marine environment of
Elliott Bay; the substrates and waters adjacent to the site contain habitat characteristics common
to both environments. Currently, the usual and accustomed fishing grounds of the Suquamish
and Muckleshoot Tribes include the site and adjacent areas, and impacts to potential tribal
shellfish collection from the beach areas must be minimized to the greatest extent practicable.
16
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
1. SUMMARY OF SITE RISKS
Human health and ecological risk assessments were conducted for both the Upland Unit
and the Marine Sediments Unit to evaluate the potential for current and future impacts of site-
related contaminants on receptors inhabiting or visiting the PSR site. The references cited in the
following section are listed at the end of the Section.
7.1 Upland Unit Human Health Risks
In 1990, Environmental Toxicology International (ETI) evaluated the potential risks to
the health of aquatic and human receptors. Only those chemicals associated with wood
preservatives and representing the greatest risk were evaluated and included selected PAH and
metals, PCP and dioxins and furans. This risk assessment was designed to support interim
response actions and determine the need for further investigations. Only limited data were
available for the evaluation of Upland Unit site risks.
Several human health risk scenarios were examined based on future land use options.
Risks of an industrial worker getting cancer from ingestion of soil and inhalation of vapors
ranged as high as 1 in a 100 (1E-02), primarily from high molecular weight PAHs, arsenic,
dioxins and furans. Cancer risks under a residential scenario were higher (1 in 10 to 1 in a 100;
1E-01 to 1E-02), using only a soil ingestion pathway. Risks of contracting cancer for a
recreational user of the site were one to two orders of magnitude lower (1 in a hundred to I in
10,000; 1E-02 to 1E-04). All of these risks are greater than the acceptable risk ranges
established by the NCP and the Washington State Model Toxics Control Act (MTCA) and
establish the need for further action.
Early actions performed in the Upland Unit eliminated the risks associated with site
exposure associated with current and expected future land use. Specifically, capping the upland
area eliminated any risk associated with direct contact with contaminated soil, and because
groundwater in the immediate vicinity of the Upland Unit is saline and not considered potable,
no risks to upland receptors based on exposure to contaminated groundwater exist. Groundwater
monitoring data and modeling results indicate that groundwater is currently meeting regulatory
requirements at the point of discharge to Elliott Bay. The excess lifetime risk associated with the
upland portion of the site (i.e., soil and groundwater) has been addressed. Furthermore, the
current and long-term use of the upland property as an intermodal rail yard and container storage
eliminates any future risks to human health or the environment associated with the Upland Unit.
Given that the only remaining risks at the PSR site are associated with the Marine Sediments
Unit, only those risks are described in detail in this ROD.
7.2 Marine Sediments Unit Human Health Risks
The human health risk assessment evaluated potential cancer and non-cancer risks to
subsistence fishers, as represented by tribal fishers, who may consume above-average amounts of
fish and shellfish from the site. Two types of risk were assessed: residual risks, or the risks
remaining after a given area of the contaminated sediment is remediated; and baseline risks, or
17
-------
Pacific Sound Resources Super/and Site: Record of Decision September 1999
those risks that currently exist at the Marine Sediments Unit. The former type of risk was
calculated to determine reductions in risk for several cleanup scenarios.
7.2.1 Identification of Chemicals of Concern
Contaminants evaluated in the human health risk assessment included those chemicals
that exceeded SMS criteria, were known to bioaccumulate, were widespread throughout the site,
exceeded risk-based screening values or exceeded Elliott Bay background concentrations, if
screening values were not available. Overall, individual PAHs, PCBs, and dioxins and furans
were retained for the risk assessment. Mercury was initially evaluated, but was not detected in
fish or shellfish tissue, and was eliminated from further study.
7.2.2 Exposure Assessment
The objective of the exposure assessment was to identify potential exposure scenarios by
which contaminants of concern in site media could contact humans and to quantify the intensity
and extent of that exposure. The conceptual site model depicting potential receptors and
exposure pathways were presented in Section 5 (see Figure 3).
The exposure assessment focused on exposure of tribal fishers to site contaminants
through consumption offish and shellfish from the Marine Sediments Unit. Fish were chosen as
a medium of concern because they were found to contain contaminants that were also detected in
sediment collected from the Marine Sediments Unit which were associated with historical site
activities. English sole were used as surrogate species to represent bottom fish because of their
abundance at the site, extensive contact with sediment, and limited home range. Shellfish were
also evaluated because edible shellfish (primarily crab and shrimp) are found in the Marine
Sediments Unit. Clams were used as a surrogate species for all shellfish because of their close
association with sediment and potential for human consumption. However, most shellfish
consumption related to the Marine Sediments Unit is expected to come from shrimp and crab
because of the limited intertidal habitat available for clamming and restricted access to the
shoreline. Tables 9 and 10 identify the fish and shellfish exposure point concentrations for the
chemicals of concern.
Both an average tribal fisher scenario and a reasonably maximally exposed (RME) tribal
fisher scenario were evaluated to show the range of potential risks at the site. Consumption rates
for fish and shellfish, as presented in a seafood consumption survey of the Tulalip and Squaxin
Island Tribes of Puget Sound (Toy et al. 1996), were used as the data representing Native
American fish and shellfish consumption patterns specific to the Puget Sound area. Data from
this study, as well as Liao and Pblissar (1996), which provided a more detailed analysis of the
Toy et al. (1996) shellfish consumption data, were also used to modify the portions of consumed
fish and shellfish that were considered likely to come from the MSU. Exposure point
concentrations for consumers offish and shellfish under current conditions and various cleanup
scenarios were determined using a linear sediment to biota transfer model because fish tissue
data were limited.
18
-------
Pacific Sound Resources Super/and Site: Record of Decision September 1999
7.2.3 Toxicity Assessment
The human health toxicity assessment quantified the relationship between estimated
exposure (dose) to a contaminants of concern and the increased likelihood of adverse effects.
Risks of contracting cancer due to site exposure are evaluated based on toxicity factors (cancer
slope factors or CSFs) promulgated by EPA (see Table 11). Quantification of non-cancer
injuries relies on published reference doses (RfDs) (see Table 12).
CSFs are used to estimate the probability that a person would develop cancer given
exposure to site-specific contaminants. This site-specific risk is in addition to the risk of
developing cancer due to other causes over a lifetime. Consequently, the risk estimates
generated in risk assessments are frequently referred to as "incremental" or "excess lifetime"
cancer risks.
RfDs represent a daily contaminant intake below which no adverse human health effects
are expected to occur. To evaluate noncarcinogenic health effects, the human health impact of
contaminants is approximated using a hazard quotient (HQ). Hazard quotients are calculated by
comparing the estimates of site-specific human exposure doses with RfDs. Values greater than
1.0 are considered to represent a potential risk.
Of the site-related contaminants of concern in fish and shellfish that potentially impact
human health, only dioxins and some PAHs are considered to be carcinogenic. The potential
cancer risks posed by these compounds were evaluated using EPA's toxicity equivalency factor
(TEF) approach.
For PAHs, this approach assigned toxicity potency factors to carcinogenic PAHs relative
to the toxicity of benzo(a)pyrene [B(a)P]. A total B(a)P equivalent concentration was derived by
multiplying each individual carcinogenic PAH concentration by its equivalency factor and
summing the results. Carcinogenic PAHs were combined and referred to as total B(a)P
equivalents. Carcinogenicity from B(a)P equivalents was evaluated using the CSF for
benzo(a)pyrene identified in the Integrated Risk Information System (IRIS; EPA 1997) (see
Table 11).
Dioxin and furan compounds were also evaluated using a TEF approach, by which
2,3,7,8-TCDD equivalents were derived by multiplying each individual dioxin and furan
congener by its equivalency factor and summing the results. A CSF for dioxin from the Health
Effects Assessment Summary Tables was used (see Table 11).
A non-cancer RfD was identified for only one non-carcinogenic PAH (pyrene; see Table
12). No RfDs were available for dioxin, benzo(a)pyrene or its equivalents, or
benzo(g,h,i)perylene or phenanthrene.
7.2.4 Risk Characterization
For carcinogens, risks are generally expressed as the incremental probability of an
individual's developing cancer over a lifetime as a result of exposure to the carcinogen. This
"excess lifetime cancer risk" is calculated from the following equation:
19
-------
Pacific Sound Resources Super/and Site: Record of Decision September 1999
Risk = GDI x CSF
where: risk = a unitless probability (e.g., 2 x 10"5 or 2E-5) of an individual's developing
cancer
GDI = chronic daily intake averaged over 70 years (mg/kg-day)
CSF = slope factor, expressed as (mg/kg-day)-1.
(See Table 13 for a summary of the input parameters used in risk calculations.)
Risks are probabilities that usually are expressed in scientific notation (e.g., IxlO'6 or
1E-6). An excess lifetime cancer risk of 1E-6 indicates that an individual experiencing the
reasonable maximum exposure estimate has a 1 in 1,000,000 chance of developing cancer as a
result of site-related exposure. This is referred to as an excess lifetime cancer risk because it
would be in addition to the risks of cancer individuals face from other causes such as smoking or
exposure to too much sun. The chance of an individual developing cancer from all other causes
has been estimated to be as high as 1 in 3. EPA's generally acceptable risk range for site-related
exposures is 1E-4 to 1E-6. Washington State Model Toxics Control Act (MTCA) rule is similar,
but with the acceptable lower risk range of 1E-5.
The potential for noncarcinogenic effects is evaluated by comparing an exposure level
over a specified time period (e.g., lifetime) with an RfD derived for a similar exposure period.
An RfD represents the level that an individual may be exposed to a given chemical that is not
expected to cause any deleterious effect. The ratio of exposure to toxicity is called a hazard
quotient (HQ). An HQ less than 1 indicates that an individual's dose of a single contaminant is
less than the RfD, and that toxic effects from the chemical are unlikely. The Hazard Index (HI)
is generated by adding the HQs for all chemicals of concern that affect the same target organ
(e.g., liver) or that act through the same mechanism of action within a medium or across all
media to which a given individual may reasonably be exposed. An HI less than 1 indicates that,
based on the sum of all HQ's from different contaminants and exposure routes, toxic
noncarcinogenic effects from all contaminants are unlikely. An HI greater than 1 indicates that
site-related exposures may present a risk to human health.
The HQ is calculated as follows:
Non-cancer HQ = CDI/RfD
where:
GDI = Chronic daily intake
RfD = reference dose.
GDI and RfD are expressed in the same units and represent the same exposure period (i.e.,
chronic, subchronic, or short-term).
20
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
7.2.5 Cancer Risks
The results of the human health risk characterization indicated that cancer risks to
subsistence fishers are the primary concern under current conditions. Cancer risks represent an
individual's chance of developing cancer due to ingestion of seafood from the Marine Sediments
Unit, over and above those exposures associated with general activities in a lifetime. Under
current conditions, total cancer risks for the RJME individual (high-end tribal fisher) are 5.2 in
10,000 (5E-4), when both PAHs and PCBs are considered (see Table 14). Given the
uncertainties associated with estimating risks, this probability is considered accurate within an
order of magnitude. Thus site risks under current conditions exceed the NCP risk ranges of 1E-6
to 1E-4. MTCA risk ranges do not apply directly to sediment; however, MTCA risk ranges
would also be exceeded under current conditions.
7.2.6 Non-Cancer Risks
Under current conditions, non-cancer hazard indices to RME individuals based on
exposure to PAHs are less than 1.0, indicating that non-cancer effects for these chemicals are
likely minimal for the site. Inclusion of PCBs in the non-cancer risk assessment suggests that
significant impacts to human health may occur from eating contaminated seafood (HI = 4) (see
Table 15).
7.2.7 Discussion of Residual Risk Calculations
Residual risks (i.e., risk remaining after cleanup) for human consumers of seafood were
calculated to allow comparisons among the alternatives. Individual sample data collected as part
of the RI were replaced with the SQS, CSL or background chemical concentrations, depending
on the configuration of the remedy. It was assumed that dredging would achieve the selected
standard (either the SQS or CSL), while capping would achieve the Elliott Bay background
concentration. Once the sample concentrations were replaced with the post-remedial action
predicted sediment concentrations for the chemicals of concern, clam and fish tissue
concentrations were estimated using a biota-sediment accumulation factor for each sample
location. The 90th percentile of the resulting tissue concentrations was then used as the exposure
point concentration in the human health risk assessment. The calculated residual risk for each
alternative is listed in the Description of Alternatives Section.
7.2.8 Uncertainties
Risks to human health may be over- or underestimated based on the appropriateness of
the assumptions regarding exposure, the availability and assumptions associated with the
derivation of toxicity factors, and the use of a bioaccumulation model to represent exposure point
concentrations. These inherent uncertainties were accounted for by making assumptions that
tended to overestimate risk. For example, when calculating residual risk for a capping scenario,
it is understood that some volume of capping material will be deposited in non-target areas (i.e.,
areas not in exceedance of the cleanup goals). The residual risk calculations do not reflect this
additional risk reduction. However, the uncertainties in any risk assessment affect the
21
-------
Pacific Sound Resources Super/and Site: Record of Decision September 1999
estimations of risk such that EPA believes that the estimates are only accurate to within an order mljk
of magnitude. ^^
7.3 Marine Sediments Unit Ecological Risks
The ecological risk assessment evaluated the health of benthic invertebrate communities
and bottom fish populations. The benthic community evaluation was based on multiple effects
measures, including sediment toxicity bioassays, in situ benthic community structure, and clam
tissue bioaccumulation data. The bottom fish evaluation was based on fish tissue
bioaccumulation data and the use of a simple linear model to estimate the transfer of
bioaccumulative contaminants from a fish to its eggs.
7.3.1 Identification of Chemicals of Concern
Similar to the human health risk assessment approach, contaminants evaluated in the
ecological risk assessment included those chemicals that exceeded SMS criteria, were known to
bioaccumulate, were widespread throughout the site, and exceeded Elliott Bay background
concentrations. Overall, individual PAHs, PCB, and dioxins and furans were retained for the
risk assessment. Mercury was not evaluated because it was not detected in fish or shellfish
tissue.
7.3.2 Exposure Assessment
Ecological Setting
The Marine Sediments Unit consists primarily of deep subtidal habitat, as nearly all
intertidal wetlands and shallow subtidal aquatic habitats in the vicinity have been eliminated as a
result of urban development. Intertidal habitat does exists within the Marine Sediments Unit, but
is limited to two pocket beaches at the head of the West and Main Slips and as thin bands of
muddy sand beach along the toe of the riprapped banks. Because the Marine Sediments Unit is
located in a transition zone between the estuarine environment of the Duwamish River and the
marine environment of Elliott Bay, the substrates and waters adjacent to the site contain habitat
characteristics common to both environments.
Biota utilizing the habitat within the Marine Sediments Unit include a variety of marine
invertebrates, estuarine and marine fishes (including salmonids), birds, and marine mammals.
Some of these species have been classified by the State of Washington and federal government
as species of special concern (i.e., requiring protective measures for their perpetuation due to
their population status, sensitivity to habitat alteration, and/or recreational, commercial, or tribal
importance). Table 16 presents the ecological receptors and exposure pathways of concern for
the site. In addition, Chinook salmon and Bull trout have been listed on the federal Endangered
Species List.
Exposure Point Concentrations
Exposure point concentrations were derived for sediment, benthic infauna, clams, fish,
and fish eggs. Contaminant-specific exposure point concentrations for surface sediment were
22
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
represented on a station-by-station basis (rather than combined for the area) because the
receptors within the benthic community are expected to have limited movement and are more
likely to spend their entire lives at single, defined locations within the sediment environment.
Sediment exposure point concentrations were represented by the laboratory results for PAHs and
dioxins and furans, with TOC normalization of PAHs (where appropriate) and conversion of
dioxin and furan congener-specific data to 2,3,7,8-TCDD equivalents (see Table 17).
Benthic exposures were also evaluated on a station-by-station basis and were represented
by measures (averages) of major taxonomic group (i.e., crustacean, mollusc, and polychaete) and
species-level abundance and richness. The average values for these endpoints were calculated
from the replicate samples collected at each station.
Contaminant exposure to clams inhabiting the Marine Sediments Unit was estimated by
directly measuring the concentrations of contaminants of concern in unpurged, whole body bent-
nose clam (Macoma nasuta) tissues exposed to site sediments in a laboratory test (see Table 18).
Similarly, contaminant exposure based on bioaccumulation in English sole was estimated by
directly measuring 2,3,7,8-TCDD in whole body adult tissues offish collected from the site (see
Table 19). A maternal-egg transfer approach was used to model 2,3,7,8-TCDD exposures to fish
eggs. Studies from Nimi (1983) and EPA (1993) were used as the basis for assessing the
maternal transfer of TCDD.
7.3.3 Ecological Effects Assessment
Several different criteria were used to evaluate potential toxicity to a range of ecological
receptors at the site. Effects-based criteria (i.e., SMS and AET chemical screening values) were
used to evaluate toxicity to benthic organisms exposed to contaminated sediment. These criteria
represent chemical-specific threshold concentrations above which adverse ecological impacts to
the benthic community would be expected. Site-specific toxicological impacts from combined
chemical contamination were also evaluated by comparing growth and mortality responses of
organisms exposed to sediment collected from the site to responses of organisms in clean control
sediments. These toxicological tests included amphipod, echinoderm embryo, and clam
bioassays and comparisons with SMS biological criteria (or criteria modeled after SMS). Site-
specific toxicological impacts from combined chemical contamination were also evaluated by
comparing site-collected benthic infaunal community data, including measures of abundance and
diversity, to similar samples collected from Elliott Bay (background).
Chemical-specific toxicity evaluations were conducted for measured concentrations of
Contaminant of concern in fish collected from the site and in clams exposed to site-collected
sediment. Estimates of fish egg concentrations were made based on a simple maternal transfer
model. Toxicity to fish and eggs was also evaluated using literature-based effects concentrations
of chemicals in fish tissues and background concentrations of chemicals in clam tissue.
7.3.4 Risk Characterization
Results of the ecological risk assessment showed that existing sediment contamination
has low to moderate impacts on benthic invertebrate communities residing in the Marine
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
Sediments Unit. No risks were calculated for clams because of a lack of effects data in the
literature. However, clams are exposed to site-related contaminants at levels exceeding Elliott
Bay background concentrations, indicating the possibility that deleterious impacts could occur to
this receptor. No risks to fish or fish eggs based on exposure to bioaccumulative contaminants in
sediment were identified for the existing conditions in the Marine Sediments Unit. However,
risks to fish from PAH exposures were not evaluated because tissue concentrations were
considered a poor representation of exposure and potential effects, due to the metabolic
breakdown of PAHs in vertebrates. As part of the review of the Feasibility Study, CERCLA
Natural Resource Trustees (NOAA, Interior, Ecology, and the Suquamish and Muckleshoot
Tribes) provided EPA with a restoration goal for the site, based on effects to flatfish. The
restoration goal is 2,000 ug/kg (measured on a dry weight basis) total PAHs in sediments and is
based on a sum of the concentrations of selected PAHs. Elliott Bay background concentrations
currently exceed the restoration goal, as does the site, indicating that flatfish populations may be
at risk throughout Elliott Bay.
7.3.5 Uncertainties
Risks to ecological receptors may be over- or underestimated based on the
appropriateness of the background benthic area selected for comparison with Marine Sediments
Unit data, the accuracy of the laboratory bioassays in predicting impacts to in situ receptors, the
assumptions regarding the site-specific bioavailability of contaminants, the accuracy of the
predictions of exposure to clams and fish that were based on average tissue concentrations and
chemical detection limits, the use of a model to predict chemical concentrations in fish eggs, and
the assumptions associated with effects levels for fish. However, similar to the approach used
for conducting the human health risk assessment, these inherent uncertainties were accounted for
by making assumptions that generally overestimate risk. The exception to the general
overestimation is associated with the impact of PAHs on flatfish, as there is no standard
methodology to evaluate this pathway.
7.4 Basis for Response Action
Contaminated sediment in the Marine Sediments Unit represents a threat to aquatic
receptors (primarily fish and higher order receptors) and people consuming seafood from the site.
The response action selected in this ROD is necessary to protect the public health and welfare
and the environment from hazardous substances that occur in the surface sediments of the
Marine Sediments Unit.
Wood-processing and related industrial chemicals released from the PSR Upland Unit or
discharged from the Longfellow Creek overflow channel have been retained in the sediments
composing the PSR Marine Sediments Unit. The chance of a tribal fisher developing cancer or
other non-carcinogenic effects related to consumption of site-contaminated seafood exceeds the
acceptable risk range identified in the NCP.
Aquatic invertebrates may be harmed by ingestion or exposure to contaminated
sediments, depending on the sensitivity to PAHs exhibited by a species (i.e., not all species may
be affected). However, recent work by the National Marine Fisheries Service (Homess et al.
24
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
1998) suggests that flatfish (or other fish in direct contact with sediments) may be at risk for
impaired growth or reproduction or suppressed immune responses, not only at the site but
throughout Elliott Bay.
References for Section 7
EPA. 1997. IRIS Online Database.
EPA. 1995. HEAST Online Database.
EPA. 1993. Interim Report on Data and Methods for Assessment of 2,3,7,8-
Tetrachlorodibenzo-p-dioxin Risks to Aquatic Life and Associated Wildlife. U.S. EPA Office of
Research and Development, Washington, D.C. EPA/600/R-93/055.
Horness, B.H., D.P. Lomax, L.L. Johnson, M.S. Meyers, S.M. Pierce, and T.K. Collier. 1998.
Sediment Quality Thresholds: Estimates from Hockey Stick Regression of Liver Lesion
Prevalence in English Sole (Pleuronectes vetulus).
Liao, Shiquan, and Nayak Polissar. 1996. Results of Re-Analysis of the Tulalip and Squaxin
Island Fish Consumption Data. Technical Memorandum. 30 September 1996.
Nimi, A.J. 1983. Biological and Toxicological Effects of Environmental Contaminants in Fish
and Their Eggs. Department of Fisheries and Oceans, Canada Centre for Inland Waters,
Burlington, Ontario. L7R 4A6. Can J. Fish Aquat. Sci. 40:306-312
Toy, K.A., N.L. Polissar, S. Liao, and G.D. Mittelstaedt. 1996. A Fish Consumption Survey of
the Tulalip and Squaxin Island Tribes of the Puget Sound Region. Tulalip Tribes, Department of
Environment, Marysville, WA.
8. REMEDIATION OBJECTIVES
8.1 Upland Unit
The remedial action objectives for the groundwater pathway are: 1) Protection of aquatic
life in surface water and sediments form exposure to contaminants of concern above protective
levels, and 2) protection of humans from exposure to groundwater containing contaminants of
concern above protective levels. These objectives are currently being met through the
implementation of the early actions. Additional remedial measures will ensure that the early
actions remain protective.
8.2 Marine Sediments Unit
The remedial action objectives for sediments associated with this site are: 1) to minimize
human exposure through seafood consumption and 2) minimize benthic community exposure to
site contaminants. These objectives will be met through remediation of the sediments exceeding
the following State standards: 1) the minimum cleanup standard (CSL) under the State Sediment
Management Standards for sediments contaminated with PAHs (creosote related contamination),
25
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
and 2) the State's sediment quality standard (SQS) for sediments contaminated with PCBs in the
near shore environment. PCB cleanup can be easily addressed during PAH cleanup and may
increase the overall health of Elliott Bay. A more stringent cleanup goal was chosen for PCBs
due to their potential for bioaccumulation in the food chain. These cleanup levels will result in
approximately 50 acres of contaminated sediments being actively remediated. Human exposure
to contaminated seafood and benthic exposure to contaminated sediment associated with this site
will be nearly eliminated in the capped areas, as the fish, shellfish, and benthic community will
no longer be exposed to the contaminated sediment. Rather they will exposed to the clean
sediment imported for capping material.
8.3 Key Applicable or Relevant and Appropriate Requirements
The key Applicable or Relevant and Appropriate Requirements (ARARs) for PSR
include the Alternative Cleanup Levels (ACLs) and the State Model Toxics Control Act
(MTCA) for groundwater, and the Washington Sediment Management standards for the marine
sediments, as described below.
8.3.1 Upland Unit
Alternate Concentration Limits for Groundwater
Usable groundwater should be returned to beneficial uses wherever practicable within a
reasonable restoration time frame (40 CFR 300.430(a)(iii)(F)). If groundwater is a current or
potential future source of drinking water, remedial actions must reduce contaminant
concentrations to or below nonzero maximum contaminant level goals (MCLGs) or maximum
contaminant levels (MCLs) established under Safe Drinking Water Act regulations (40CFR
300.430(e)(i)(B). However, under the following circumstances, alternate concentration limits
(ACLs) in accordance with CERCLA Section 121(d)(2)(B)(ii) may be used (40 CFR
300.430(e)(i)(F):
The groundwater must have a known or projected point of entry to surface water
Measurements or projections must show that there is or will be no statistically significant
increase of such constituents in the surface water at the point of entry or at any point
where accumulation of constituents may occur downstream
The remedial action must include enforceable measures that will preclude human
exposure to the contaminated groundwater at any point between the facility boundary and
all known and projected points of groundwater entry into surface water
MTCA (WAC 173-340-720(l)(c)) lists parallel requirements, and the PSR site meets the criteria
as follows:
Groundwater from the PSR site discharges directly into Elliott Bay at known or projected
points (see Figure 10).
Uplands RI/FS calculations of constituent concentrations from shoreline monitoring well
data project that there will be no statistically significant increase in contaminants in Elliott
Bay, after groundwater contaminant concentrations are attenuated between the shoreline
26
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
wells and the marine water/sediment interface (i.e., the mudline). Under the MTCA, the
shoreline wells would be considered an alternate point of compliance, as they will be used
to predict the contaminant concentration at the mudline.
Enforceable institutional controls outlined in this ROD will preclude human exposure to
on-site groundwater and any groundwater between the site and Elliott Bay.
Both Class II and Class III groundwater exist at PSR (see Figure 10). Class III
groundwater occurs where saltwater intrusion (i.e., the saltwater wedge) raises total dissolved
solids concentrations above 10,000 mg/L. Class II groundwater occurs above and upgradient of
the 10,000 mg/L boundary. The assignment of Class II to this groundwater is consistent with
EPA's definition of a potential source of drinking water (i.e., one available in sufficient quantity
to meet the needs of an average household.)
Restoration of Class II groundwater at PSR is impracticable. DNAPL at PSR represents
a long-term continuing source of contamination to groundwater. The DNAPL is widespread and
the distribution is complex as a result of the interbedding of coarse and fine-grained soil layers in
the aquifer (Sections 4.2.2, 4.2.3 and 9.1.4 of the Upland RI/FS). Currently available remedial
technologies cannot restore the aquifer to drinking water standards.
Based on the groundwater classification at PSR, the impracticability of restoration, and
the impracticability of the site meeting the statutory requirements, use of ACLs at PSR is
appropriate. The ACLs for the PSR site are the maximum allowable source concentrations. A
fate and transport analysis was conducted using the Domenico Solution to determine allowable
source concentrations at shoreline monitoring wells that ensure protection of receptors at the
mudline. The mechanisms modeled between the shoreline wells and the mudline were
dispersion, sorption, diffusion and tidal dilution. The contribution of biodegradation was not
included due to a lack of site-specific degradation data.
Alternate concentration limits were calculated for each of the shoreline well-sets that
span shallow (9 to -6 feet MLLW), intermediate (-20 to -40 feet MLLW) and deep (-75 to -85
feet MLLW) screen intervals. For each set, the maximum allowable source concentrations are
based on the minimum estimated travel distance between the well-screen and the mudline. As
shown in Table 20, many of the calculated ACLs exceeded individual compound solubilities
which are the maximum dissolved concentrations possible at equilibrium (i.e., compound is not
predicted to dissolve at a high enough rate to exceed the ACL). Compliance with ACLs will be
confirmed by groundwater monitoring in shoreline wells.
8.3.2 Marine Sediments Unit
Washington Sediment Management Standards (WAC 173-204)
The Washington Sediment Management Standards (SMS) have been identified as one
key ARAR for all Marine Sediments Unit actions. The SMS establish a narrative standard with
specific biological effects criteria and numerical chemical concentrations for Puget Sound
sediment. Under the SMS, the cleanup of a site should result in the elimination of adverse
effects on biological resources and health threats to humans. The Sediment Quality Standards
27
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
(SQS) correspond to this narrative goal for ecological effects. Site-specific cleanup standards are
established from a range of concentrations; they are to be as close as practicable to the SQS and
no greater than the minimum cleanup levels (MCUL; equivalent to the CSL), based on
environmental effects, .feasibility, and cost.
Given site-specific factors, the CSL for PAHs has been selected as the trigger for active
remediation of sediments throughout the PSR Marine Sediments Unit and the SQS for PCBs has
been selected as the trigger for active remediation of sediments in the nearshore environment
(i.e., sediments shallower than -10 feet MLLW). Table 20 summarizes these values.
The justification for the selection of the CSL for PAHs is as follows:
The CSL is protective of benthic communities (as determined by biological sampling).
Human health risks fall within the risk range required by the NCP.
Cleanup costs to achieve the SQS across the entire site were greater than 190 percent of
the cost to achieve CSLs (greater than 110 percent is considered significant under the
SMS guidance).
Cleanup to the CSL addresses the areas of contaminated sediment accumulations, which
contain the greatest mass of contaminants.
The majority of the unremediated sediments that will remain following cleanup are in
deep (greater than 100 feet) water, providing minimal exposure potential to fishers and
recreational users of the bay.
The justification for the selection of the SQS for PCBs in the nearshore environment is as
follows:
The nearshore environment provides critical habitat for juvenile salmonids and their prey.
The CSL for PCBs does not provide the same degree of protection as other chemicals
because it does not address bioaccumulative effects.
Cleanup of PCBs to SQS ensures that the Trustees' restoration goal for PAHs is met in the
shallow, nearshore critical habitat area (some nearshore areas were PCBs exceed the SQS
also include PAH contamination that exceeds the SQS).
9. DESCRIPTION OF ALTERNATIVES
The Upland Unit and Marine Sediments Unit remedial alternative descriptions are
presented separately. The completed and on-going Upland Unit actions and the selected Marine
Sediments Unit alternative, in combination, constitute the PSR site-wide remedy.
28
-------
Pacific Sound Resources Superfund Site: Record of Decision - ' September 1999'
9.1 Upland Unit
9.1.1 Completed Early Actions
Early cleanup actions were completed to address threats posed by contaminated soil and
groundwater and shallow NAPL in the Upland Unit. Included in these actions were the
installation of a subsurface containment wall and LNAPL collection trench along the northern
site perimeter and the placement of a low-permeability surface cap over the Upland Unit. The
subsurface slurry wall was designed to minimize flow of contaminated groundwater and LNAPL
to Elliott Bay and reduce tidal influence on contaminant movement below ground surface. The
selection of this particular containment option is discussed below. The purpose of the cap was to
isolate contaminated soil and reduce groundwater recharge (and associated contaminant
mobilization). Early actions were completed prior to the RI/FS process.
Two general response actions were considered for subsurface containment: hydraulic
containment and physical containment. Physical containment was selected primarily because
LNAPL seeps to Elliott Bay could be prevented. Three types of physical containment
technologies were evaluated: sheetpiles, slurry walls, and grout curtains. Grout curtains were
eliminated based on technical feasibility concerns; the integrity of curtains in heterogeneous fill
conditions and high groundwater tables is uncertain. Slurry wall technology was selected rather
than sheet pile technology due to its lower cost. The final remedial action selected was the
implementation of an upland hanging slurry wall.
PSR groundwater meets cleanup requirements under the NCP and threshold requirements
for cleanup actions under MTCA without implementation of additional engineered remedial
measures. What was selected as an early action is the final action, and the development and
detailed evaluation of a series of cleanup alternatives was not required for the Upland Unit.
9.1.2 Requirements to Ensure Upland Unit Actions Remain Protective
Engineering Controls
A Inspection and Maintenance (I&M) program was developed to ensure the long-term
structural integrity of the cap installed over the Upland Unit. The program consists of scheduled
visual cap inspections and specific repair and maintenance protocols. Additionally, every five
years the Port will evaluate the need to resurface the Upper two inches of the asphalt and
determine if reapplication of the cap seal coat is warranted.
Institutional Controls
Institutional controls are the use of legal or administrative systems to reduce the potential
for human exposure to contaminated soil and groundwater in the Upland Unit. As described in
Section 6, the current and projected future land use of the Upland Unit is primarily industrial
(i.e., use as a paved intermodal rail yard) and the groundwater beneath the PSR site will not be
used as a potable water supply. The institutional controls necessary to ensure the continued
protection provided by the early actions are actions that will assure the current land use is
maintained and the aquifer remains unused.
29
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
Monitoring
Confirmational monitoring is a routine requirement under CERCLA, as well as one of the
threshold requirements for cleanup actions under MTCA and is the central purpose of the plan.
Monitoring is intended to confirm the long-term effectiveness of the early actions.
Monitoring of the Upland Unit will consist of two components. The first component is
the monitoring of groundwater quality to ensure compliance levels continue to be met (i.e.,
concentrations of contaminants of concern do not exceed cleanup levels at the mudline).
Because the direct measurement of water quality at the mudline is impracticable, monitoring
wells located in the shoreline area are utilized to evaluate compliance. These wells allow for
monitoring of groundwater quality at two depths outside the containment wall and along the
shoreline.
The second component is designed to monitor DNAPL attenuation. This monitoring is
required to confirm the conclusion in the RI that the volume of mobile, free-phase DNAPL
beneath the site is very limited, and to provide a warning in the case of an unexpected change in
conditions. This component consists of gauging DNAPL thickness in wells and removing
DNAPL from wells.
9.2 Marine Sediments Unit
Six candidate alternatives were identified in the Marine Sediments Unit FS:
1. No Action
2. Removal (via dredging and disposal) of sediment exceeding the CSL
3a. Capping of sediment exceeding SQS
3b. Capping of sediment exceeding CSL
4a. Fill Area Removal (via dredging and disposal) of sediment exceeding the SQS and then
capping the remaining non-Fill Area sediment exceeding SQS
4b. Fill Area Removal (via dredging and disposal) of sediment exceeding the CSL and then
capping the remaining non-Fill Area sediment exceeding CSL.
9.2.1 Estimated Cleanup Areas and Volumes
The numeric cleanup goals to attain the Marine Sediments Unit Remedial Action
Objectives (RAOs) are the SMS criteria. The PSR cleanup levels are CSLs for PAHs
(throughout the Marine Sediments Unit) and SQS for PCBs (in less the -10 feet MLLW). See
Table 5 for a summary of these levels. The areas with surface sediment exceeding SQS or CSL
criteria for PAHs are depicted in Figure 9. The SQS exceedance area represents about 96 acres
and 970,000 cubic yards of contaminated material; within that area, 47 acres or approximately
470,000 cubic yards of sediment also exceed CSLs. Nearly all sediment volume exceeding CSL
30
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
and SQS criteria (90 and 85 percent, respectively) is located at depths of less than -200 feet
MLLW.
The majority of the contaminant mass exists in the Fill Area. The Fill Area sediment
contains approximately 96 percent of the mass of contaminants exceeding the SQS criteria, while
comprising only 39 percent of the total volume of SQS-contaminated sediment, and contains
approximately 98 percent of the mass of contaminants exceeding the CSL criteria, while
comprising only 70 percent of the total volume of CSL-contaminated sediment.
9.2.2 Common Components of Alternatives
With the exception of the No Action alternative, each of the sediment remedial
alternatives for Marine Sediments Unit share certain components, such as institutional controls
and short- and long-term monitoring. For dredging and disposal, additional common elements
include methods of sediment removal and transport, and potential disposal site options. For
capping, additional common components include cap material availability, methods of material
transport and placement, and navigational constraints. Table 21 provides a summary of Marine
Sediments Unit remedial alternatives and summarizes which common elements are associated
with each alternative. Brief discussions of the common alternative components are provided
below.
Another common element to the Marine Sediments Unit remedial alternatives is that they
all include the requirements to ensure the Upland Unit actions remain protective (described in
Section 9.1.2) to comprise the site-wide remedial alternative for PSR.
Institutional Controls
Currently, the Upland Unit shoreline is fenced to prevent access to the shoreline (by land)
and fishing exclusion devices are installed along the viewing pier.
For alternatives with capping components, institutional controls to maintain cap
performance will be required. These controls will include administrative measures or regulatory
actions to prevent maintenance dredging and large ship anchorage in capped areas. A no-anchor
zone is proposed for all alternatives in areas that would be capped. The extent of the zone would
depend upon the size of the area capped for the alternative (see Table 21). For the alternatives
consisting primarily of capping (Alternatives 3a and 3b), the no-anchor zone would be
approximately 96 or 47 acres in size, respectively, representing about 4 or 2 percent of the total
anchorage area available in Elliott Bay (approximately 2,000 acres are designated for anchorage
within Elliott Bay). This institutional control is included to prevent damage to the cap from
commercial vessels using large whale-type anchors. Currently, the Marine Sediments Unit is
used only for barge moorage at fixed anchor buoys. This type of moorage will not be restricted.
In addition, this restriction would not affect net fishers because small boat anchors and net lead-
lines would not damage the cap.
31
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
Monitoring
Site monitoring will be conducted for all alternatives. Although specific monitoring
requirements vary depending upon the alternative, it is assumed that three types of monitoring
will be carried out. Short-term monitoring will be performed during remedial action
implementation to ensure compliance with water quality requirements, confirmational
monitoring will be implemented immediately following the action to ensure the actions was
implemented as designed, and long-term monitoring will be performed to ensure the
performance of the remedy. Specific monitoring programs will be developed for the site during
remedial design.
Dredging and Transport
Two general types of dredges, clamshell (or bucket) and hydraulic, were evaluated during
the FS as applicable to potential sediment removal actions. The dredging-specific methods
evaluated were closed clamshell dredge, cutterhead section dredge, high-energy vortex dredge,
and a limited-access hydraulic dredge, which represent the most widely used classes of dredges
available. Each of these dredges has different attributes with respect to excavation capacity,
depth limitations, sediment loss or expansion (bulking), and production rates of dredge material
(see Table 22). Comparisons among these dredges indicated that the majority of the sediments
from the Marine Sediments Unit could be removed using either a clamshell dredge or large
hydraulic dredge. For the purposes of the cost estimates, it was generally assumed that a
clamshell dredge would be used in nearshore areas and the high-energy vortex dredge in deeper,
offshore areas.
Two methods are used to transport dredged material: pipeline and barge. The actual
sediment transport method selected depends primarily on the dredging method and the distance
to the disposal site. Pipeline transport was generally assumed for cost estimate purposes, based
on the selected dredging method. However, final transport methods would be determined during
remedial design when the final dredge equipment and disposal sites are selected.
Crowley Marine Terminal Dredging
All alternatives include dredging in the area of the Crowley Marine Services (CMS)
terminal, a barge terminal at Pier 2 (just west of PSR) in order to maintain adequate depths for
maneuvering and moorage of barges. Dredging is employed to remove contaminated sediments
from the pier area, while maintaining current depths (to accommodate vessel depth requirements)
after capping. The disposal method for dredged material varies, depending on the alternative.
Capping
Capping as a remedial technology involves placement of clean substrate (typically sand)
to some specified depth over the contaminated sediments. Typical placement methods includes
controlled dumping from a split-hulled barge, hydraulic washing of capping material off a flat-
decked barge, distribution via a submerged diffhser, and clamshell placement. Requirements for
capping material depend upon site-specific characteristics, including water depth, bathymetry,
32
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
currents, and chemical and physical characteristics of the area to be capped, and are typically
determined during design. Site-specific physical constraints that affect capping include currents,
wave action, prppeller wash, slope, and depth.
For the purposes of evaluating the capping alternatives and estimating costs in the FS, a
3-foot layer of silty sand was assumed to chemically and physically confine the majority of the
Marine Sediments Unit sediments exceeding SQS or CSL criteria. Actual cap thickness
requirements are determined during design. As the accuracy of cap placement and the capability
of monitoring cap thickness is reduced with increasing water depth, it was further assumed that
an average cap thickness of 5 feet would be needed to ensure a minimum cap thickness of 3 feet
at depths greater than 200 feet MLLW. Because of the potential for resuspension of fine-
grained contaminated sediment during cap placement, it was assumed that less dynamic or
disruptive methods of sediment placement would be used in the offshore area, such as hydraulic
washing. Nearshore area placement techniques were assumed to rely on clamshell placement to
obtain desired placement accuracy.
The source of capping material was assumed to be from maintenance dredging projects
performed for navigational purposes by the U.S. Army Corps of Engineers (Corps). Table 23
presents the capping material source locations and projected availability schedules. Information
provided by the Corps indicates that the two largest sources of sediment suitable for capping are
the Snohomish and Duwamish rivers. Dredged material from these projects is anticipated to be
predominantly sand materials. Given the demands for capping material throughout Puget Sound,
coordination with the Puget Sound Dredge Materials Management Program to develop priorities
and schedules for the beneficial reuse of clean dredge material will be needed.
In addition to navigational dredging projects, the dredging of clean sediments in other
areas was considered as an alternative capping material source and deemed inappropriate. The
mining of clean sediment could have a deleterious effect on the benthos if large areas were
mined in order to get the quantity of sediment needed quickly and is difficult to get permitted. In
addition, capping the sediment over several years (as necessitated by the projected availability
capping material from maintenance dredging projects) will allow the benthic community to re-
establish itself between capping events such that a large area is not disrupted at one time.
Another benefit of capping over several years is that it allows the effectiveness of capping at
depth and over steep slopes to be better established through monitoring to perfect the operation
from one year to the next.
Ground-water Discharge Zone Capping
The intermediate groundwater discharge zone, located in the west-central portion of the
Marine Sediments Unit, has been identified as an area susceptible to recontamination (due to
predicted groundwater contaminant transport in this area). To achieve cleanup goals and long-
term protectiveness, a three-foot cap would be placed in the intermediate groundwater discharge
zone for all alternatives. In alternatives where dredging is performed first, capping would
follow.
33
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
9.2.3 Disposal Sites
Disposal options for contaminated dredged sediment consist of confined nearshore
disposal (CND), confined aquatic disposal (CAD), or upland disposal. During the FS, the CND
option was identified as preferable for alternatives involving the disposal of relatively large
volumes of dredged sediment (i.e., Alternative 2, 4a, and 4b).
Confined Nearshore Disposal
A CND facility is typically constructed adjacent to an upland area such that the site can
be used as an extension of the upland when the site is filled with sediment. Potential nearshore
disposal sites were identified based on several selection criteria. To qualify as a potential
nearshore disposal site, the area had to be located in Elliott Bay. In addition, the geomorphology
of the site had to be stable enough to allow the construction of a retaining berm. Location of
nearshore disposal facilities could not conflict with current land or shoreline uses or tribal fishing
activities. The site could not be located in high-value aquatic habitat areas or habitat restoration
or enhancement areas. Ten sites were evaluated according to these criteria. Of the 10 sites
evaluated, only the nearshore areas associated with PSR and the former Lockheed Shipyard #2
which is adjacent to PSR, is currently available for use as a disposal site for dredged material
from PSR. In general, CND facilities can be constructed as an extension to the upland, or at
intertidal and/or subtidal elevations. Although evaluated, an intertidal CND site was not selected
for further consideration due to inadequate capacity.
The construction of a CND site has been proposed for the above-mentioned Lockheed
facility by Ecology. The CND facility is proposed to be constructed off the north shore of the
Lockheed site extending eastward from the PSR site to the West Waterway. The facility consists
predominantly of an intertidal disposal area supported by a constructed subtidal area. Site
capacity would be filled by the Lockheed site cleanup in the current site configuration.
However, if the CND at Lockheed was reconfigured to result in a final elevation equivalent to
the current upland, the facility could accommodate PSR sediments. Integration of the PSR
nearshore disposal site with the Lockheed intertidal disposal site would consist of constructing
the Lockheed site such that it abuts the east side of the PSR disposal site and the utilization of the
east side of the PSR berm for confinement. Two nearshore disposal site configurations were
retained as CND facility options with capacities of 350,000 cubic yards to 480,000 cubic yards.
The CND facility berm could consist of riprap with sand infill to act as a barrier to
sediment migration through any gaps in the riprap. Dredge water from inside the disposal area
could be released through a notch in the top of the berm. Modified elutriate tests (METs) were
performed to predict the effluent quality from nearshore dewatering operations. The test results
indicate that the discharge of separable dredge water could result in exceedances of federal
marine acute ambient water quality criteria (AWQC) for two LPAHs (phenanthrene and
naphthalene). To protect water quality during the dewatering of dredged sediment, the separable
dredge water would be detained using an oil boom and/or activated carbon filter and treated prior
to discharge. Water quality sampling would be performed to ensure contaminant levels were
acceptable.
34
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
To maintain slope stability, dredging of contaminated sediments would not be conducted
adjacent to the riprap containment berm. Capping of the sediments adjacent to the CND would
be the preferred option.
For cost estimation purposes, it was assumed that vortex hydraulic dredging would be
used to minimize solids resuspension, and the hydraulically dredged solids would be pumped via
floating pipeline. The area within the berm would be filled with contaminated sediment to an
elevation of approximately 10 feet MLLW to ensure that the sediments remain saturated. The
remaining three to five feet would be filled with clean material to serve as a cap.
To incorporate habitat into the PSR nearshore disposal facility design, the outer perimeter
of the berm should be covered with fine substrate conducive to benthic habitat. This would
create a 5-acre intertidal area extending outward from the top of the berm to a distance of
approximately 150 feet at a 3:1 slope. It would range in elevation from -35 feet MLLW to 15
feet MLLW.
Confined Aquatic Disposal
A CAD facility would consist of consolidating the contaminated dredged sediment on a
minimally sloping section of Elliott Bay and covering it with clean sand. Potential CAD sites
were identified based on several criteria, including proximity to PSR, physical dimensions of the
site, neighboring activities, and ecological importance of the site. Specifically, only sites located
in Elliott Bay were considered. In addition, sites had to be located at depths between -80 and -
200 feet MLLW and have a slope of 6 percent or less. The final consideration was that the site
could not be located in high-value aquatic habitat areas or designated mitigation areas. Based on
these criteria, two potential CAD sites were identified.
CAD Site 1 is located approximately 0.5 miles northeast of the PSR upland site and lies adjacent
the PSDDA disposal site boundary. CAD Site 2 is located in the northwest portion of Elliott Bay
near Terminal 91 and the Elliott Bay Marina. This site is approximately 3 miles north-northeast
of the PSR upland site.
To minimize water quality impacts at the CAD disposal site, contaminated sediments
should have high density for faster settling and less spreading upon placement into the CAD.
Therefore, to implement the CAD disposal option, it would be necessary to dredge Marine
Sediments Unit sediments with a closed clamshell dredge to maintain greater than 60 percent of
the in situ sediment density. (Note: descriptions and evaluations of alternatives assume the use
of a vortex hydraulic dredge).
The native sediments in the area of the CAD sites would be dredged to form a depression
in which to place the contaminated sediment. This depression, in conjunction with capping,
would confine the contaminated sediment. The clean dredged material could be temporarily
placed adjacent to the selected CAD site for capping material. Alternately, a berm could be
constructed and the dredged sediment placed within this bermed area. The estimated capacity of
each site assumes the site is dredged 15 feet deep with side slopes of 10H: 1V.
35
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
The volume of clean material required to cap the CAD site was determined using a target
thickness of 6 feet (5 feet plus 20 percent material loss) to ensure a 3-foot minimum thickness
was achieved over the dredged material. The capping material should be composed primarily of
sand to minimize material losses of finer-grained materials.
Upland Disposal
Upland disposal consist of dewatenng sediment and disposing of the de watered sediment
in an existing landfill or a newly constructed upland facility. Based on the maximum
concentration of contaminants reported in the RI, it is assumed that the sediments would not be
considered a Dangerous Waste as defined in Washington State Regulation, and could be
disposed of as a solid waste. In addition, pursuant to RCRA (40 CFR Part 261.4(g)), because
this dredged material will be subject to the requirements of Section 404 of the Clean Water Act,
this material is not a RCRA hazardous waste.
Twelve areas were recommended by the Corps as potential sites for the construction of
new upland disposal facility. These sites were evaluated based on current land use and site
characteristics. Ten sites were eliminated from further consideration based on current land use
(i.e., golf course, park, or watershed buffer zone). Of the two remaining sites, the first is owned
by the City of Kent and consists of approximately 152 acres zoned for industrial use. This
undeveloped property is located south of South 212th Street and east of the Green River. The
eastern portion of the site (approximately 30 acres) is located within the 100-year floodplain.
The site is flat and the depth to groundwater is approximately 10 to 15 feet bgs. This site is
located approximately 18 miles (via Interstate 5) from PSR. The second site is owned by the
City of Renton and consists of approximately 73 acres zoned for industrial use. This
undeveloped property is located south of Southwest 27th Street, and east and west of Long Acres
Parkway, within 0.5 mile (east) of the Green River. The site is flat and the depth to groundwater
is approximately 10 to 15 feet bgs. This site is located approximately 16 miles from PSR via
Interstate 5 and SR-405.
For the remedial alternatives it is assumed that vortex hydraulic dredging would be used
to remove the contaminated sediments from the Marine Sediments Unit. The hydraulically
dredged sediments would be transported to a dewatering system consisting of two 2-to 3-acre
dewatenng cells (site is currently undetermined, but would need to be in close proximity). After
dewatering, the sediments would be transported to the upland disposal site via trucks (rail access
is not available for either of the two potential disposal sites).
Construction of a lined landfill would be needed to contain the dredged sediments.
Washington State Code requires at least 10 feet between the bottom of a landfill and the seasonal
high water elevation; therefore, the landfill would need to be constructed above the ground
surface. Assuming the dredged material was placed with a 10-foot average fill thickness, a
minimum of 35 acres would be needed to contain 480,000 cubic yards (Alternatives 2 and 4a),
and a minimum of 25 acres would be needed to contain the 315,000 cubic yards (Alternative 4b)
of dredged material. Due to shallow groundwater at the potential disposal sites, sufficient
capping material may not be available from landfill construction. Capping material would need
to be imported or obtained from other portions of these sites not used for the landfill.
36
-------
Pacific Sound Resources Superfurid Site: Record of Decision .- September 1999
Alternatively, an established landfill could be used. Sediment dewatering could be
performed using dewatering cells near the point of dredging (as suggested above). The sediment
may also require stabilization to ensure no free water was present prior to transport, potentially
necessitating the addition of 10 to 50 percent stabilizing agent by volume. Alternatively,
sediment could be pumped to intermodal containers (if rail cars are to be used for transport) and
dewatered in place using a vacuum system. The dewatered sediment could be loaded into trucks
or transported by rail to an appropriate existing landfill.
9.2.4 Description of the Alternatives
Each candidate alternative represents a combination of the major elements described
above. This section presents summarized alternative descriptions. Detailed descriptions are
presented in the Marine Sediments Unit FS; however, several modifications have been made to
the alternatives since the FS report. These changes include: 1) capping the nearshore areas with
5 feet of material, rather than 3 feet of material, to preserve tribal fishing rights, 2) disposing of
sediment dredged at the CMS Terminal in an existing upland disposal facility, rather than
placing it off-shore under a cap, and 3) implementing mitigation actions with nearshore sediment
disposal. Therefore, alternative costs and capping material volumes presented herein differ
slightly from those provided in the FS.
Alternative I No Action
The No Action alternative represents a baseline against which the effectiveness of other
sediment remedial alternatives can be compared. Under the No Action alternative, no removal or
isolation of the contaminated sediment would occur, and no engineering or administrative
controls would be implemented to prevent exposure of contaminants to human or ecological
receptors. Potential impacts of the No Action alternative include the following:
Continued potential for human health effects associated with consumption of
contaminated fish and shellfish
Continued bioaccumulation of chemicals of concern in the aquatic food chain
Continued low- to moderate-level impacts to the benthic communities (reducing the value
of contaminated areas as habitat for fishery resources)
Continued loss of contaminants to the water column (i.e., via dissolution)
Continued acute and chronic toxicity to marine organisms associated with Marine
Sediments Unit sediment
Potential off-site transport of contaminated sediments to other areas within Elliott Bay
Under the No Action alternative, the human health risks associated with site-related
contaminants would remain at their current level of approximately 5 in 10,000 with a non-cancer
Hazard Index of 4.
37
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
Alternative 2 - Removal to the CSL
Alternative 2 consists of dredging the majority of sediments from the Marine Sediments
Unit that exceed CSL criteria, disposing of the dredged sediment in a nearshore disposal site, and
capping isolated areas for which dredging is not a feasible alternative due to concerns regarding
slope stability, recontamination, or dredging impracticability. Dredging and disposal of all
sediment that exceeds SQS criteria was not considered for detailed evaluation under this
alternative for several reasons. First, it would be technically very difficult, as removal would be
required beyond the practical depth limitations for dredging of 200 feet. Second, no local
disposal sites were identified that could accommodate 970,000 cubic yards of dredge material,
thereby limiting sediment disposal options. Finally, it was determined that other, less-expensive
technologies (e.g., capping) could provide the same level of protectiveness at a cost substantially
less than the $60 million estimated for nearshore disposal of sediment dredged to the SQS.
Dredging of sediment exceeding CSL criteria would be conducted from the nearshore
area to a maximum depth of-200 feet MLLW (the assumed practical limits for dredging).
Approximately 33 acres of the Marine Sediments Unit would be dredged to depths ranging from
approximately 4 to 16 feet below mudline, resulting in the removal of approximately 372,000
cubic yards of sediment. Dredged sediments would be transported directly to a CND site.
Assuming a 15 percent bulking factor, the disposal facility would require a storage capacity of
approximately 428,000 cubic yards. If a CND site is not feasible, the dredged sediment would
be disposed in a CAD facility or dewatered and placed in a newly constructed upland disposal
facility.
Under this alternative, capping would also be conducted in three areas: along the
shoreline, within the intermediate groundwater discharge zone west of the Main Slip, and in
offshore areas with CSL exceedances that are at depths greater than -200 feet MLLW. Sediment
in these areas would be isolated by 3-foot caps (excluding intertidal areas which are covered with
a 5-foot cap) requiring a total volume of approximately 115,000 cubic yards of clean sediment
and covering a total estimated area of 14.3 acres. This alternative requires an implementation
period of approximately 2.7 years, depending upon the availability of capping material.
Under this alternative, the residual human health risks associated with site-related
contaminants left in place would be approximately 1 in 10,000. The resulting non-cancer Hazard
Index associated with the site would be less than 1.0.
The total cost of this alternative is approximately $22,388,000 using the nearshore
disposal option, $13,714,000 using the CAD disposal option, and $25,270,000 using a newly
constructed upland disposal facility option. The following cost table summarizes the dredging
costs (see Table 26 for cost estimation assumptions):
Capitol Cost Annual O&M Total Present Worth
34,806.000 $79,860 $6,010,000
38
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
The estimated cost of Alternative 2 is as follows:
Total Present Worth: 6,010,000
+ CND Disposal: 11,128,000
+ Mitigation: 5,250,000
= Total Cost: $22,388,000
Alternative 3a - Capping to SQS
Alternative 3a consists of capping all sediments that exceed the SQS except where
capping would interfere with navigation at the CMS terminal. In this area, limited dredging
would be performed prior to capping. Approximately 3,500 cubic yards of sediment would be
dredged from this area (to a depth of approximately 3 feet below mudline), dewatered and placed
in an existing upland disposal facility.
Placement of a 3-foot cap over all sediments contaminated with PAHs at concentrations
greater than SQS criteria and placement of 5 feet of material in the intertidal areas would require
a total of approximately 786,000 cubic yards of sediment, isolating an estimated 96 acres of
offshore, shoreline, and groundwater discharge zone contaminated sediments. Based on the
limited annual availability of capping material, the cap would be constructed in stages over a
five-year span.
Residual human health risks associated with site-related contaminants would be
approximately 3 in 100,000. The resulting non-cancer Hazard Index associated with the site
would be less than 1.
The total cost of this alternative is approximately $13,139,000, including the costs
for the disposal of dredged sediment in an existing upland facility. The following table
summarizes the capping costs (see Table 27 for cost estimation assumptions):
Capitol Cost Annual O&M Total Present Worth
$9,613,000 $191,400 $12,520,000
The estimated cost of Alternative 3a is as follows:
Total Present Worth: 12,520,000
+ Existing Upland Disposal: 619,000
* Mitigation: N/A
= Total Cost: $13,139,000
39
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
Alternative 3b - Capping to CSL
Alternative 3b consists of capping all sediment that exceeds the CSL-based cleanup goals
for PAHs and those nearshore areas (less than -10 feet MLLW) that exceed the SQS for PCBs.
In addition, the shoreline area will be capped with five feet of material. Like Alternative 3a,
limited dredging would be performed prior to capping at the CMS terminal and the dredged
sediment would be dewatered and placed in an existing upland disposal facility.
Placement of a 3-foot cap over all sediments contaminated with PAHs at concentrations
greater than CSL criteria, and placement of 5 feet of material in the intertidal areas would require
a total of approximately 371,000 cubic yards of sediment, isolating an estimated 47 acres of
offshore, nearshore, and groundwater discharge zone contaminated sediments. As with
Alternative 3b, capping would be conducted in stages over an approximate 4-year span based on
the availability of Puget Sound maintenance dredge material.
Residual human health risks associated with site-related contaminants after capping to
CSLs would be approximately 4 in 100,000. The resulting non-cancer Hazard Index associated
with the site would be less than 1.
The total cost of this alternative is approximately $7,059,000, including the costs for
the disposal of dredged sediment in an existing upland facility. The following table
summarizes capping costs (see Table 28 for cost estimation assumptions):
Capitol Cost Annual O&M Total Present Worth
$4,930,000 $105,285 $6,440,000
The estimated cost of Alternative 3b is as follows:
Total Present Worth: 6,440,000
+ Existing Upland Disposal: 619,000
+ Mitigation: N/A
= Total Cost: $7,059,000
Alternative 4a Fill Area Removal to SQS and Capping
Alternative 4a consists of dredging the fill area to depths that achieve SQS criteria
(thereby removing 96 percent of the mass of contaminants exceeding SQS criteria) and capping
all remaining sediment (outside of the fill area) that exceeds these criteria. In addition, similar to
Alternatives 2, 3a and 3b, limited dredging would be performed at the CMS terminal prior to
capping.
A total of approximately 381,500 cubic yards of material would be dredged from the 24-
acre Fill Area, the 4-acre groundwater discharge zone, and the 4-acre CMS Terminal area.
40
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
Sediment removed from the CMS Terminal would be placed outward of the CMS where capping
would occur in conjunction with the rest of the Marine Sediments Unit, The remaining dredged
sediments would require disposal in a facility with a storage capacity of approximately 439,000
cubic yards (assuming a 15 percent bulking factor). Dredged sediments would be transported
directly to a CND site: If a CND site is not feasible, the dredged sediment would be disposed in
a CAD facility or dewatered and placed in a newly constructed upland disposal facility. This
decision would be made during remedial design.
A 3-foot cap would be placed over the remaining 70 acres of sediment exceeding SQS
chemical criteria, extending from near the shoreline to a depth of approximately 240 feet
MLLW. Approximately 577,000 cubic yards of capping material would be required to ensure
adequate containment. An additional 8,000 cubic yards of sediment would be required to
establish a 5-foot cap over the intertidal areas. As with Alternatives 3a and 3b, capping would be
done in stages over an approximate 5-year span based on the availability of clean, Puget Sound
maintenance dredge material.
For fill removal and capping to SQS, the residual human health risks associated with the
remediated site would be approximately 7 in 100,000. The resulting non-cancer Hazard Index
associated with the site would be less than 1.
The total cost of this alternative is approximately $29,094,000 using the nearshore
disposal option, $20,332,000 using the CAD disposal option, and $32,185,000 using a newly
constructed upland disposal facility option. The following cost table summarizes the dredging
and capping costs (see Table 30 for cost estimation assumptions):
Capitol Cost Annual O&M Total Present Worth
$10,024,000 $159,200 $12,430,000
The estimated cost of Alternative 4a is as follows:
Total Present Worth: 12,430,000
+ CND Disposal: 11.414,000
+ Mitigation: 5.250,000
= Total Cost: $29,094,000
Alternative 4b Fill Area Removal to CSL and Capping
Alternative 4b consists of dredging the fill area to depths that achieve CSL criteria
(thereby removing 98 percent of the mass of contaminants exceeding CSL criteria) and capping
all remaining sediment (outside of the fill area) that exceeds these criteria. As with Alternative
4a, limited dredging would also be performed in the groundwater discharge zone and at the CMS
terminal prior to capping.
41
-------
Pacific Sound Resources Superfand Site: Record of Decision September 1999
A total of approximately 273,500 cubic yards of material would be dredged from the fill
area and the CMS terminal area. Dredged sediments would be transported directly to a confined
nearshore disposal (CND) site. If a CND site is not feasible, the dredged sediment would be
disposed in a CAD facility or dewatered and placed in a newly constructed upland disposal
facility. This decision would be made during remedial design.
A 3-foot cap would be placed over the approximately 24 acres of sediment exceeding
CSL chemical criteria, requiring approximately 154,000 cubic yards of capping material. An
additional 8,000 cubic yards of sediment would be required to establish a 5-foot cap over the
intertidal areas. As with Alternatives 3a and 3b, capping would be done in stages over an
approximate 3-year span based on the availability of clean, Puget Sound maintenance dredge
material.
For fill area removal and capping to CSLs, the residual human health risks associated
with the remediated site would be approximately in 2 in 10,000. The resulting non-cancer
Hazard Index associated with the site would be 4.
The total cost of this alternative is approximately $18,040,000 using the nearshore
disposal option, $11,170,000 using the CAD disposal option, and $19,675,000 using a newly
constructed upland disposal facility option. The following cost table summarizes the dredging
and capping costs (see Table 31 for cost estimation assumptions):
Capitol Cost Annual O&M Total Present Worth
$4,585.000 $60,870 $5,500,000
The estimated cost of Alternative 4b is as follows:
Total Present Worth: 5,500,000
+ CND Disposal: 8,190,000
-t- Mitigation: 4,350,000
= Total Cost: $18,040,000
10. COMPARATIVE ANALYSIS OF ALTERNATIVES
This analysis addresses the Marine Sediments Unit alternatives.
10.1 Overall Protection of Human Health and the Environment
This criterion evaluates whether an alternative achieves and maintains adequate
protection of human health and the environment. All of the alternatives except the "No Action"
alternative would provide adequate protection by eliminating, reducing, or controlling risk
through removal or containment, or a combination of the two. The relative degree of
protectiveness has been determined by how clean the remaining surface sediment will be
42
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
following cleanup. The assumption that lower contaminant concentrations result in higher
sediment quality was used to rank the alternatives for overall protection. The lowest degree of
remaining surficial sediment contamination would be achieved through capping because clean
sediment would be used. While dredging would remove any sediment that exceeded the cleanup
goal, it would not remove all contaminated sediment down to the "native" or background level
(i.e., the remaining sediment would not be as clean as what would be brought in for capping).
The highest degree of protectiveness is provided by capping the contaminated sediment with
clean sediment.
10.2 Compliance with Applicable or Relevant and Appropriate Requirements (ARARs)
This criterion evaluates how each alternative complies with Federal and State statutes
and regulations that pertain to the site. All alternatives, with the exception of the "No Action"
alternative, comply with ARARs.
10.3 Long-Term Effectiveness and Permanence
This criterion evaluates the ability of an alternative to maintain protection of human health and
the environment over time. Long-term effectiveness factors in the reliability of the remediation
alternative and the degree of monitoring and maintenance that will be required. While all
remediation alternatives, except the "No Action" alternative, provide long-term effectiveness and
permanence (assuming current conditions), removing contaminated sediment and consolidating it
in a disposal facility is more reliable than capping in place because removal and placement
results in a smaller and more controlled area of contaminated sediment. In addition, an
engineered disposal facility (specifically a nearshore fill or upland disposal site) is easier to
inspect, monitor and maintain than a larger capped area in the aquatic environment. Alternatives
with comparatively more dredging than capping rate higher under this criterion.
10.4 Reduction in Toxicity, Mobility and Volume Through Treatment
This criterion evaluates an alternative's use of treatment to reduce the harmful effects of
principal contaminants, their ability to move in the environment, and the amount of
contamination present. None of the alternatives reduce toxicity, mobility or volume through
treatment. Treatment was evaluated for sediment cleanup, however was screened out of further
consideration for the following reasons: 1) there are currently no effective in situ treatments (i.e.,
treating in place) for sediments covering a large area or subjected to significant flushing, and 2)
any ex situ treatment would require significant material handling (excavation, de-watering,
transport, and processing) and extreme cost (estimated at $40 million excluding material
handling).
10.5 Short-term Effectiveness
This criterion evaluates the length of time needed to implement an alternative and the
risks the alternative poses to workers, residents, and the environment during implementation.
Short-term environmental impacts include water quality impacts, biota exposure and habitat loss
(i.e., fisheries impacts) during the implementation of the remedial alternative. Dredging
43
-------
Pacific Sound Resources Super/and Site: Record of Decision September 1999
alternatives would result in 1) greater water quality and fisheries impacts due to the disturbing
and suspending of contaminated sediment, 2) greater worker exposure to contaminants due to the
comparatively greater contaminated material handling, and 3) a slightly greater potential for
worker injury resulting from the use of dredging machinery (more mechanically complex than
capping equipment). Capping alternatives that would result in short-term loss of aquatic habitat
due to covering the existing benthic community. Capping may also suspend contaminated
sediment. It is important to note that much of the short-term risk associated with both dredging
and capping can be significantly reduced by carefully choosing methodology and monitoring
techniques. The duration of these short-term effects is generally proportional to an alternative's
implementation period, including disruption of fisheries activities or other water-dependent uses.
Capping generally has greater short-term effectiveness than dredging because it can be
implemented more quickly. Alternative 3b for example, which is primarily capping, has an in-
water implementation period of 11 months Alternative 4b, which combines more dredging with
capping has an in-water implementation period of 15 months. And, Alternative 2, which is
primarily dredging has an in-water implementation period of 14 months. The time required to
site and build a disposal facility to accommodate the larger volumes of dredge material is not
included in the in-water estimates.
10.6 Implementabiliry
This criterion evaluates the technical and administrative feasibility of implementing the
alternative. Implementability includes the ease of construction, the availability and capacity of
materials and/or facilities, and logistical and/or administrative practicability. Ease of
construction is similar for dredging and capping. There are uncertainties associated with both
technologies (i.e., for capping; material placement difficulties on slopes and at depth, and for
dredging; material control concerns regarding dewatering and resuspension). Capping requires a
volume of material that won't be available immediately and will require several years of
maintenance dredging to procure. Similarly, dredging requires that a disposal facility be sited,
which is a'time-consuming and politically very difficult process. Placement of a cap would
require moorage restrictions to ensure that anchors do not harm the cap and expose/distribute
contaminated sediment. Due to the historically extreme difficulty in siting a disposal facility, the
capping alternatives have an ultimately higher degree of implementability than dredging
alternatives.
10.7 Cost
This criterion includes estimated capital and operation and maintenance costs as well as
present worth costs. Cost estimates are expected to be accurate within a range of +50 to -30
percent. Current estimates indicate that capping is the least costly alternative, and dredging with
its associated disposal costs is the most costly. See Table 25 for a summary of all the
alternative's costs.
44
-------
Pacific Sound'Resources Super fund Site: Record of Decision September 1999
10.8 State Acceptance
This criterion evaluates whether the State of Washington agrees with the U.S. EPA 's
analyses and recommendations of the RI/FS and the Proposed Plan. The Washington State
Department of Ecology concurs with EPA's Selected Remedy.
10.9 Community Acceptance
This criterion evaluates whether the local community agrees with U.S. EPA 's analyses
and preferred alternative. One phone call was received regarding the Proposed Plan for the PSR
site. The caller left a message in support of the Preferred Alternative (and now the Selected
Remedy). Many comments were received from State and Federal departments and agencies.
Those comment and EPA's responses are included as Part 3, the Responsiveness Summary of
this ROD.
11. SELECTED REMEDY
The Selected Remedy for the PSR site addresses both the Upland Unit and Marine
Sediments Unit.
11.1 Upland Unit
Early cleanup actions were completed to address threats posed by contaminated soil and
groundwater and shallow NAPL in the Upland Unit. Included in these actions were the
installation of a subsurface containment wall and placement of a low-permeability surface cap
over the Upland Unit. The t-arly actions for soils and groundwater removed the most
contaminated source material, eliminated direct contact with soils, eliminated soil transport to
Elliott Bay, eliminated leaching of surface soil contaminants to groundwater, minimized
potential future direct contact with subsurface soils, eliminated LNAPL discharges to Elliott Bay,
minimized discharge of contaminated groundwater and DNAPL to Elliott Bay and significantly
reduced the influence of tidal fluctuations at the site. The risk posed by exposure to contaminated
soil has been eliminated, and groundwater meets cleanup requirements under the NCP and
threshold requirements for cleanup actions under MTCA without implementation of additional
engineered remedial measures. What was implemented as early action is final action for the
Upland Unit. The Selected Remedy for the Upland Unit is:
Inspection and Maintenance (I&M) of the surface cap; on both the Port of Seattle's
intermodal yard working surface and the public access area. These actions will be in
accordance with the I&M plans established during the early actions and contained in the
Administrative Record.
Monitoring groundwater contaminant concentrations and DNAPL volume trends.
Alternate concentration limits have been established for PSR groundwater. These limits
apply at the shoreline monitoring wells (see Table 20 for list of PSR ACLs). Groundwater
will not impact Elliott Bay waters or sediment as long as these limits are met. EPA will
evaluate additional remedial measures if groundwater monitoring trend analysis indicates
these limits are being or will be exceeded. In addition, NAPL will continue to be
45
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
collected from on-site wells and disposed of in accordance with the RCRA Land Disposal
Restriction treatment standards (i.e., incineration). A groundwater monitoring plan will be
created and available for review prior to implementation. The estimated costs for Upland
groundwater monitoring and NAPL collection are listed in Table 32.
Institutional Controls for prohibiting groundwater use and restricting land use. The early
actions will remain protective as long as the I&M plans are implemented and land and
groundwater use are unchanged. Current land use is industrial with some controlled
public access, and groundwater is not used at all. Record notification of these restrictions
will be recorded against the property deed, and restrictive covenants ensuring conforming
use will be required of any subsequent purchasers. The State has declared the
groundwater to be non-potable; no drinking water wells will be permitted.
11.2 Marine Sediments Unit
The Selected Remedy for the Marine Sediments Unit is:
Confinement (through capping) of contaminated marine sediments that exceed the CSL
for PAHs or the SQS for PCBs (criteria are listed in Table 5). The SQS for PCB will be
used to trigger cleanup for sediment at depths equal to or shallower than -10 feet MLLW.
The capped area will encompass approximately 50 acres of contaminated sediment. The
cap will physically isolate the contaminated marine sediment from the biological receptors
(i.e., the benthic community, fish and humans), stabilize the sediment within the capped
area to the extent practicable, and ensure that contaminant migration through the cap is
effectively eliminated.
The thickness of the cap will be determined through design studies (see following design
discussion), however no less than 5 feet of clean material will be placed over the intertidal
area.
Dredging of approximately 3,500 cubic yards of contaminated sediment from the area to
the north of Crowley Marine Services. The purpose of dredging this material is to
maintain current navigational depths and access to Crowley Marine Services. The
dredged material will be disposed of in an established upland solid waste landfill.
Unused pilings throughout the Marine Sediments Unit will be removed prior to capping.
The pilings will be cut at the mudline and clean cap material placed over the portion
remaining in the sediment.
The clean capping material used will be at least as clean or cleaner than the SQS and will
be obtained from routine maintenance dredge projects in local rivers. In addition, capping
material will be selected and placed in such a way as to provide appropriate habitat for the
marine organisms natural to this area.
Cap placement techniques will be determined during design (see following design
discussion).
The entire capped area will be designated as a "no-anchor" zone. The no-anchor
designation will apply to commercial vessels using the large "whale-tail" type anchors
that have the capacity to break through the cap and expose contaminated sediment. This
46
-------
Pacific Sound Resources Superfitnd Site: Record of Decision September 1999
institutional control will be implemented through Federal rule-making by the U.S. Coast
Guard and the Corps in consultation with the State Department of Natural Resources. The
rule-making will be subject to public comment. MTCA Institutional Controls
requirements will be met.
Both a short- and long-term monitoring or management plan will be developed to ensure
that the cap is placed as intended and is performing the basic confinement functions.
Specific monitoring requirements will be included to address the intermediate
groundwater discharge zone. The durations of the specific monitoring requirements will
be addressed in the monitoring plan. In addition, this plan will address the monitoring
approach to be implemented following any unusually significant seismic or storm event in
the Elliott Bay area. The monitoring/management plan will also address data
management, and contingency plans in the event the cap is not meeting the remedial
objectives. These monitoring plans will be available for Natural Resource Agency's
review prior to implementation.
11.3 Issues to be Addressed During the Design Phase of the Selected Remedy
As discussed above, several elements of the remedy will be evaluated during design:
Cap thickness will be designed to physically isolate, stabilize and chemically isolate the
contaminated marine sediments. This will be completed in accordance with the Guidance
for In Situ Subaqueous Capping of Contaminated Sediments (EPA 905-B96-004). In
addition, a determination will be made regarding whether additional engineered features
are necessary to maintain the thicker cap in the nearshore area. If it is determined to be
necessary, the remedial design will include these features.
Cap placement techniques will be evaluated (and pilot test(s) conducted) to determine an
optimized construction procedure (i.e., most efficient and least environmentally
impacting) for placing clean material over the contaminated marine sediment to achieve
the basic functions. The optimized construction procedure will take into account the
geotechnical properties of both the in situ sediment and capping material, as well as the
bathymetric configuration of the contaminated sediment (i.e., slope).
Figure 11 depicts the proposed marine sediments capping area, and capping cost
estimation details are listed in tables 28 and 29.
The Total Present Worth Cost of the Selected Remedy is $7,600,000.00. (This cost
includes upland monitoring and marine capping. It does not include Upland I&M because those
costs are anticipated to be borne by the Port of Seattle as part of their ongoing operation of the
intermodal facility.)
The Selected Remedy will meet environmental and human heath protection goals through
controlled containment (i.e., capping) while leaving contamination in place. The decision to cap
contaminated marine sediment is based in significant part on a cap's ability to meet the remedial
action objectives at a lower cost than dredging and disposal alternatives. While capping will
raise short-term water quality concerns, the potential for impacts is much lower than for
alternatives that involve dredging large volumes of contaminated material. Another significant
47
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
factor against dredging large volumes of contaminated material is the historically extremely
controversial and time-consuming process of siting an aquatic or nearshore disposal facility. The
selected alternative does include dredging a small volume of contaminated sediment in order to
maintain navigation, however this material can be disposed of in an established upland solid
waste landfill. While the volume of material necessary to cap the contaminated sediment in the
Marine Sediments Unit will not be available to allow the action to be completed in one season,
this is less of a detriment than it might seem. Working with smaller portions of capping material
over time will allow for trials of various placement techniques including an evaluation of
comparative capping efficacy and durability.
11.4 Estimated Outcomes of the Selected Remedy
The Selected Remedy will greatly reduce the environmental impacts associated with the
current sediment contamination because the material used for capping will have contaminant
concentrations equivalent to or lower than background Elliott Bay concentrations. Human health
risk will be reduced by an order of magnitude. This alternative has relatively minimal impacts to
fisheries and other water-dependant industries because it can be completed without extended
periods of in water work, and without reduction of the fishery area. The implementation period
for this alternative is nearly 4 years due to limited capping material available each year, however
the short-term impacts are minimal and do not persist through the entire period (i.e., only during
intermittent capping phases).
12. STATUTORY DETERMINATIONS
Based on information currently available, EPA and Ecology believe the Selected Remedy
provides the best balance of tradeoffs among the alternatives with respect to the evaluation
criteria. The EPA expects the Preferred Alternative to satisfy the statutory requirement in
CERCLA section 121(b) to: 1) be protective of human health and the environment; 2) comply
with ARARs; 3) be cost-effective; 4) utilize permanent solutions and alternative treatment
technologies or resource recovery technologies to the maximum extent practicable; and 5) satisfy
the preference for treatment as a principal element.
Under CERCLA Section 121 and the NCP, the lead agency must select remedies that are
protective of human health and the environment, comply with applicable or relevant and
appropriate requirements, are cost-effective, and utilize permanent solutions and alternative
treatment technologies or resource recovery technologies to the maximum extent practicable. In
addition, CERCLA includes a preference for remedies that employ treatment that permanently
and significantly reduces the volume, toxicity, or mobility or hazardous wastes as a principal
element and a bias against off-site disposal of untreated wastes. The following sections discuss
how the Selected Remedy meets these statutory requirements.
12.1 Protection of Human Health and the Environment:
The Selected Remedy will be protective of human health and the environment.
Implementation of the I&M plans, monitoring plans and institutional controls for the Upland
Unit will ensure that the protection provided by the early actions is maintained. Placement of
48
-------
Pacific Sound Resources Super/and Site: Record of Decision - September 1999
clean cap material over the contaminated sediments will isolate the contaminants from the
environment. The benthic community will have clean substrate to colonize, and fish and
shellfish (the route to human exposure) will no longer be subjected to contaminated sediment in
the area of the cap. In addition, bottom fish and anadromous fish will benefit from improved
habitat in the nearshore area. Human health risk will be reduced by an order of magnitude (from
4.5E-04 to 4.2E-05 for the reasonable maximally exposed individual). The background risk
calculated for Elliott Bay is 2.9E-05, so the Selected Remedy will reduce the risk associated with
the site to essentially urban background levels. Implementation of this remedy may create some
short-term risk to the environment through resuspension of contaminated sediment, however
design studies as well as practice with various placement techniques will be utilized to minimize
any short term impacts.
12.2 Compliance with Applicable or Relevant and Appropriate Requirements (ARARs)
The Selected Remedy will comply with all applicable or relevant and appropriate
requirements as follows:
12.2.1 Upland Unit ARARs
State Model Toxics Control Act
(WAC 173-340-720(1)(C)) This is applicable to establishing cleanup levels for
groundwater.
(WAC 173-340-440) This is applicable to establishing institutional controls.
(WAC 173-340-730(3)) This is applicable to establishing cleanup standards for
surface water. (These standards are currently being met.)
(WAC 173-340-360(4),(6)) This is applicable to cleanup technologies and restoration
timeframes.
(WAC 173-340-704 -706) This is applicable to the use of Method A, B, and C.
12.2.2 Marine Sediments Unit ARARs
State Model Toxics Control Act
(WAC 173-340-440) This is applicable to establishing institutional controls.
Federal Water Pollution Control Act/Clean Water Act (33 USC 1251-1376; 40 CFR 100-149)
Acute marine criteria are anticipated to be relevant and appropriate requirements for
discharge to marine surface water during cap placement and sediment dredging.
49
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
Washington State Water Quality Standards for Surface Waters (WAC 173-201 A)
Standards for the protection of surface water quality have been established in Washington
state. The standards for marine waters will be applicable to discharges to surface water during
cap placement and sediment dredging.
Washington Sediment Management Standards (WAC 173-204)
Chemical concentration and biological effects criteria are established for Puget Sound
sediment and are applicable to PSR sediment cleanup. Sediment cleanup standards are
established on a site-specific basis from a range of concentrations.
State Water Pollution Control Act (RCW 90.48)/Water Resources Act (RCW90.54)
Requirements for the use of all known, available and reasonable technologies for treating
wastewater prior to discharge to state waters are applicable to any dewatering of marine sediment
prior to upland disposal. Section 401 requires certification for activities conducted under 404
authorities. The substantive requirements of a certification determination are applicable.
Construction in State Waters, Hydraulic Code Rules (RCW 75.20; WAC 220-110)
Hydraulic project approval and associated requirements for construction projects in state
waters have been established for the protection offish and shellfish. Substantive permit
requirements are applicable to cap placement. The technical provisions and timing restrictions of
the Hydraulic Code Rules are applicable to cap placement and dredging.
State Discharge Permit Program/NPDES Program (WAC 173-216, -220)
The Washington state NPDES program provides conditions for authorizing direct
discharges to surface waters and specifies point source standards for such discharges. These
standards are applicable to discharges to surface waters resulting from sediment dewatering
operations during dredging/disposal work.
Federal Clean Water Act Dredge and Fill Requirements; Sections 401 and 404 (33 USC 401 et
seq. 33 USC 1251-1316: 33 USC 1413; 40 CFR 230, 231; 33 CFR 320-330)
These regulations provide requirements for the discharge of dredged or fill material to
waters of the U.S. and are applicable to any in-water work. The 404 evaluation is complete and
is included in the Administrative Record for the PSR site. The Finding was that this project
complies with the requirements.
Federal Endangered Species Act of 1973 (16 USC 1531 et seq., 50 CFR Part 200, 402)
This regulation is applicable to any remedial actions performed at this site as this area is
potential habitat for threatened and/or endangered species.
50
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
Rivers and Harbors Appropriations Act (33 USC 403, 33 CFR 322)
Section 10 of this act establishes permit requirements for activities that may obstruct or
alter a navigable waterway; activities that could impede navigation and commerce are prohibited.
These substantive permit requirements are anticipated to be applicable to remedial actions, such
as dredging and capping, which may affect the navigable portions of the harbor.
U.S. Fish and Wildlife Coordination Act (16 USC 661 et seq.)
Elliott Bay shorelines provide potential habitat for bald eagles and other avian species,
and Marine Sediments Unit surface water is used as a salmonid migratory route. This act
prohibits water pollution with any substance deleterious to fish, plant life, or bird life, and
requires consultation with the U.S. Fish and Wildlife Service and appropriate state agencies.
Criteria are established regarding site selection, navigational impacts, and habitat remediation.
The act also requires that fill material on aquatic lands be stabilized to prevent washout. These
requirements are anticipated to be relevant and appropriate for remedial activities on the site.
Resource Conservation and Recovery Act (40CFR Part 261.4(g)
This regulation is an exemption determining dredged contaminated sediments that are
subject to the requirements of Section 404 of the Clean Water Act are not RCRA hazardous
waste.
Shoreline Management Act (RCW90.58, WAC 173-14); Coastal Zone Management Act (16 USC
1451 et seq., 15 CFR 923)
This statute is relevant and appropriate for capping activities in the shoreline area..
State Aquatic Lands Management Laws (RCW 79.90-79.96, WAC 332-30)
The final remedy must be consistent with state laws that promote environmental
protection, public access, water dependent uses, and uses of renewable resources and that
generate revenue to the state in a manner consistent with these management goals.
To Be Considered (TBCs)
TBC items are state and local ordinances, advisories, guidance documents or other
requirements that, although not ARARs, may be used in determining the appropriate extent and
manner of cleanup. Generally, TBC requirements are used when no federal or state requirements
exist for a particular situation. A list of TBCs for PSR Marine Sediments Unit remediation is
presented in Table 24.
12.3 Cost-Effectiveness
In EPA's judgment, the Selected Remedy is cost effective and represents a reasonable
value for the money to be spent. In making this determination, the following definition was
51
-------
Pacific Sound Resources Superfund Site: Record of Decision _____ September 1999
used: "A remedy shall be cost-effective if its costs are proportional to its overall effectiveness".
(NCP 300.430(f)(ii)(D)). Alternative 3 provides greater protection of human health and the
environment than the other alternatives that meet the same cleanup goal, at a lower cost. The
relationship of the overall effectiveness of this remedial alternative was determined to be
proportional to its costs and hence this alternative represents a reasonable value for the money to
be spent.
12.4 Utilization of Permanent Solutions and Alternative Treatment (or Resource
Recovery) Technologies to the Maximum Extent Practicable
EPA has determined that the Selected Remedy represents the maximum extent to which
permanent solutions and treatment technologies can be utilized in a practicable manner at this
site. The Selected Remedy treats the upland source materials constituting principal threats at the
site, achieving reduction in NAPL volume in soil and groundwater. NAPL will be targeted for
collection as a component of the on-going monitoring of this site. All NAPL collected will be
incinerated. Approximately 1,500 gallons of NAPL has been collected and incinerated to date.
12.5 Preference for Treatment as a Principal Element
Treatment of contaminated sediment to reduce toxicity or mobility of contaminants is not
considered feasible. As stated previously, treatment was evaluated for sediment cleanup,
however was not considered further for the following reasons: 1) there are currently no effective
in situ treatments (i.e., treating in place) for sediments covering a large area and subjected to
significant flushing, and 2) any ex situ treatment would require significant material handling
(excavation, de-watering, transport, and processing) and extreme cost (estimated at $40 million
excluding material handling).
12.6 Five-Year Review Requirements
Because this remedy will result in hazardous substances, pollutants, or contaminants
remaining on-site above levels that allow for unlimited use and unrestricted exposure, a statutory
review will be conducted within five years after initiation of remedial action to ensure that the
remedy is, or will be, protective of human health and the environment.
12.7 Documentation of Significant Changes from Preferred Alternative of Proposed Plan
The Proposed Plan was released for public comment in April 1999. It identified
Alternative 3b, placement of a marine cap, as the Preferred Alternative for sediment remediation.
The Preferred Alternative specified that a small volume of material would be dredged to allow
for continued navigational access to Crowley Marine Services, and the dredged material would
be placed within the area to be capped, then capped with the rest of the contaminated sediment.
Comment was received urging the use of an upland disposal site rather than replacement of the
dredged material back into the marine environment. EPA made this change in the Selected
Remedy. In addition, the Preferred Remedy as described in the Proposed Plan specified that
institutional controls would be implemented in the nearshore area to restrict shellfish harvesting.
The beach area that could be utilized for shellfish harvest is only available about 70 days of the
52
-------
Pacific Sound Resources Superfund Site: Record of Decision September 1999
year (i.e. at low tides) and access to the beach is very limited (its only accessible by boat).
Public comment indicated that institutional controls of this nature would impact tribal treaty
rights. EPA has revised the Selected Remedy to include placement of additional clean material
in the nearshore area (no less than 5 feet) which will allow for unrestricted harvest of shellfish.
These changes could have been reasonably anticipated based on the information in the
Proposed Plan. Therefore, the procedural requirement is met by discussing these changes in this
ROD.
53
-------
-------
FIGURES
-------
-------
Washington
ELLIOTT
BAY
Duwamish Head
. 0 1000 2000
Scale in Feet
PSR Upland and
Marine Sediments Unit
Location Map
Figure
1
99-0391 Fig1 fh8
-------
>*
BASEmP tXPHHATIOM
(HUES
1) UnrtfcJJ ditum ii- H«BtJ
Mnn Lawtr Low WMr (M.LW).
2) CjllmmlllL Oia MUCK NOAA. 1970 5 199S-
3) Unttoiu ol Mgny w«. LMAPL trwidi.
*) Aim not aafti «»i IBM" «! bi
omnd witt don til nd Undtaprng.
tna (poddt MvliBS) difncd
by-1 mMU.Wamtour(m)titx*m).
: UMPLFtocontyTnoeh
i A/ LocthMddMnui*cll«i
i linbiouixte
APPROVED BY:.
PSR Upland and Marine
Sediments Unit Site
Features
^_
"SI!
-------
Upland Unit
Marine Sediments Unit
Contaminated
Vadose Zone
Soils
Mean Lower Low
Water Level
Containment
LNAPL Wall
Recovery-\ \
Trench \. \
Ingestion of
Fish/Shellfish
Surface Sediment Contamination
Dermal contact, ingestion,
respiration of contaminated
interstitial water by
benthic organisms
Dissolved Chemicals
Elliott Bay
Bottom Profile
Ingestion of and dermal contact
with contaminated sediment by
benthic organisms
Ingestion of contaminated
benthic organisms by
epibenthic and pelagic
organism
Sinking Liquid
(DNAPL)
EXPLANATION
DMOMO PMM NAH.
PSR Conceptual Site Model
of Receptors and Exposure Pathways in the
Marine Sediments Unit Post-Upland Cleanup
U
-------
i
inttrnwdMt onunchntvr
(fluhir^ zon» M Mdttod with
WM*«»ntri( tfantn* w»flt
eonWnlrgDKAPL.
1
i
w^m^B£^^
2'
JlPfl ROVED BVs
8H m
GO 0 » 100 1SC 200
<^
PSR SIM
NOTES
j
i
L
PSR Marine Sediments Unit
Shoreline Cap Area
FKSUSE :
4
-------
V i
O13*'
o"1
If
4 IBM
.55- '
grain
CokcM tor AmUi. (n .
- ChmMiy Or* (n - 7)
Bfcrauyi, BMm. Sutao
(0 to 1 0 ClwrriMy (n . 9)
Pt»»»2SurI.o.(Oto10-S51
Ptwn t Suite* (OK> 10 on) Sediment
Sample - Chnmtatiy Only (n - 45)
GN UN
fsy
100 0 ICQ 20O SOU 400
1] Se« figure 2 (cc aw ignn
21 Rita 2 Btcoti. iMora EB1 1 1 and EB 1 12
an tocDMiwffmst ol EBttO.
3) Strtonj EB1 15 imt EB092 kxalM nttin ttit
LoddlMd dunup action ofan txiundaiy.
PSR Marine Sediments Unit
Phase 1, 2, and 3 Surface
Sediment Chemical and Biologi
Sampling Locations
-------
HDIES
1) S» Rgm 2 fer«B fnlure
O Snlow(Olo20f!)Sub«urtE«
S»*r«n1Co(f>.17)
» OOTp(OtoKft)SubB«tan
SadCnmlCora(n-31
ncountBnd it four stMotis
itfaitowt:
EB072: 19 flbtlow
ED113: 7 n betow muflirxi
DATE; a«etanitMr2S.l«M3^al>U
JOI UUUteR; 12}4««O-001-O134
vnw nut «MUT«J.IH..
APPROVED BY:_
PSR Marine Sediments Unit
Phase 2 Subsurface Sediment
Sampling Locations
"S
-------
.BK001
BK001D
X
Magnolia
\ Magr
Nx Bluff
TerminaJJSI
Smith |
Cove
JU^
Elliott Bay
BK002"
BK003,,
Duwamish Head
/ Alki X;
s
/ )
/ I
.BK004
N^1/> PSR
BASEMAP EXPLANATION
I
i
i
I
' / '
NQIES
11 Can Inlet reference station not siwwn. ,
600 0 500 1000 1600 2000
T 29.19M 3:25 P
23*0-O«-OOl-O1
VIEW PILE: t*ptMm«fc.»ww
CHECKED BY;
APPROVED BY:
;PSR Marine Sediments Unit
; Surface Sediment Background
i Chemical and Triad Sampling
Locations 7
-------
MAGNOLIA
Duwamish Head
!-
^
scAifizmo psHsit8
600 0 600 1000 1800 XXO
Fact
DATE S«eiwnbM2S.1fi993.2fiPU
JOBWJMBEP I
VIEW RLE. t
APPROVED 8Y:_
PSR Marine Sediments Unit
Site and Background Fish
Sampling Transects
-------
|! i '. BBtowTOCNSOSOflAET
,._.
-' / , Exlrapotelod FH Boundary
ji !" ABowTOCNSOSorLAET
I! :' - -
: g| Abov«TOCNCa.Of2LAET
!; > * Impermeable Cap
SwFigur«2forS!(» fealuf e notes andgtobafff^txjte
1) ExCMdancas based on tmividuel or group
totals for FAHt.
; 2) HI cofitoura Irom USGSsub-oottomproliling
"ijPSR Marine Sediment" Unit
JjSurface Sediment PAH Exceedance'
iiAreas and Fill Contours1
CHECKED BY: .
APPROVED BY:
Figure
9
-------
APPROXIMA1E HORIZONTAL SCAlt IN FEET
VERTICAL SCALE: 1* - 40'
1. SCALE AND ELEVATIONS ARE APPROXIMATE. HIGH AND LOW TIDE LEVELS AND
SURFACE RELIEF ARE ESTIMATED.
2. OUTSIDE THE CONTAINMENT WALL. SALT WATER is EXPECTED DUE TO TIDAL
FLUCTUATIONS THAT WILL OVERWHELM ANY FRESHWATER FLOW.
MLLW
GROUNOWATER FLOW DIRECTION
MEAN LOWER LOW WATCR
Souice: P^ii ol Seallle: Pacilic Sound Resources
RA4SWhP(3-l335-3G-«)
Approximate Location of Saltwater-Freshwater Interface
Pacific Sound Resources-Superfund Site
Figui«
10
99-0391 FirjtO.ai
-------
Shonliiw Cmn
Cap
C«p [ntitmtdlat* grgundwattf
dKcharge zone auocljtao with
WMt-cenlral sftcrelin* wflta
contilnlna DNAPL
See Figure 2 tor site features notes.
60 0 SO 100 160 W» PS ft gits
i
VM^ugfl §^7*
APPROVED BY;
j- - . ,
| j
PSR Marine Sediments Unit
Modified Alternative 3b
Capping to CSLs ng«
11
-------
-------
TABLES
-------
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 1Summary of Surface Sediment Chemical and Biological Analyses
Sample Number
Weston ID
EPA ID
Field Analysis*
Immunoassay
Physical and Chemical Analysis"
TOC | Grain Size | % Moisture
PAHs*
PCBS* IPCDD/PCDFI Metals'
Biological Analysis0
Bioassavs"
Bioaccum
Benthos
PSR Marine Sediments Unit
SD1-EB01-0000
SD1-EB02-0000
SD1-EB03-0000
SD1-EB04-0000
SD1-EB05-0000
SD1-EB06-0000
SD1-EB07-0000
SD1-EB08-0000
SD1-EB09-0000
SD1-EB10-0000
SD1-EB1 1-0000
SD1-EB12-0000
SD1-EB13-0000
SD1-EB14-0000
SD1-EB1 5-0000
SD1-EB16-0000
SD1-EB17-0000
SD1-EB1 8-0000
SD1-EB1 9-0000
SD1-EB20-0000
SD1-EB20-1000
SD1-EB21-0000
SD1-EB22-0000
SD1-EB23-0000
SD1-EB24-0000
SD1-EB25-0000
SD1-EB26-0000
SD1-EB27-0000
SD1-EB28-0000
SD1-EB29-0000
SD1-EB30-0000
SD1-EB31-0000
SD1-EB32-0000
SD1-EB33-0000
96162600
96162601
96162602
96162603
96162604
96162605
96162606
96162607
96162608
96162609
96162610
96162611
96162612
96162613
96162614
96162615
96162616
96162617
96162618
96162619
96162620
96162621
96162622
96162623
96162624
96162625
96162626
96162627
96162628
96162629
96162630
96162631
96162632
96162633
-.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-
X
-
-
X
X
X
X
-
X
X
X
-
X
X
X
X
-
-
_
_
_
X
X
-
X
X
X
X
X
X
X
X
-
X
-
-
X
-
X
-
-
X
-
X
X
X
X
X
-
_
_
X
X
X
MA
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-
-
-
-
-
-
-
-
-
-
-
_
_
_
_
_
_
_
_
_
_
_
_
_
-
_
_
_
_
_
-
-
-
-
-
-
-
-
-
-
-
- _
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
-
_
_
_
_
-
-
-
-
-
-
-
-
-
_
_
-
_
_
_
_
-
_
_
_
_
-
_
-
_
_
_
_
-
'«-()J18axls I
Page 1 of 5
9/28/1999
-------
Pacific Sound Resources Record of Decision-Marine Sediments Unit
Table 1-Summary of Surface Sediment Chemical and Blologica. Analyses
ample Nu
Weston ID
D1-EB34-OOOg
D1-EB35-0000
Physical and Chemical Analysis
Grain Size '/.Moisture
96162634
96162635
D1-EB36-OOgg
P1-EB37-OOOQ
SD1-EB3B-0000
96162636
96162637
96162639
96162639
96162640
SD1-EB39-100Q
m-EB40.QOOO
SD1-EB41-0000
5D1-EB42-0000
SD1-EB43-OOOQ
SD1-EB44-OOOQ
1D1.EB45-OOOQ
SD2-EB46-OOod
SD2-EB47-OOOQ
SD2-EB4a-OQOQ
SD2-EB49-0000
SP2-EB50-0000
SD2-EB51-0000
D2-EB52-OOOg
'SD2-EBS3-OOOQ
ISD2-E854-0000
P2-EB54-100g
[SD2-EB55-0000
96162641
96162642
96162643
96162648
96162649
96382524
96382526
96382S27
96382525
96392701
96382528
SD2-EB57-0000
D2-EB5B-OOOQ
SD2-EBS9-OOOQ
ISD2-EB60-OOOD
D2-EB61-OOQg
ISD2.EB62-OQOO
D2-ES63-OOOg
JSD2-EB64-0000
D2-EB65-0000
D2-EB66-0000
W-CUI8a.xls!
Page 2 of5
9/28/1
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 1Summary of Surface Sediment Chemical and Biological Analyses
Sample Number
Weston ID
SD2-EB67-0000
SD2-EB68-0000
SD2-EB69-0000
SD2-EB70-0000
SD2-EB71-0000
SD2-EB72-0000
SD2-EB73-0000
SD2-E874-0000
S02-EB75-0000
SD2-EB76-0000
SD2-EB77-0000
SD2-EB78-0000
SD2-EB79-0000
SD2-EB80-0000
SD2-EB81-0000
SD2-EB82-0000
SD2-EB83-0000
SD2-EB84-0000
SD2-EB85-0000
SD2-EB86-0000
SD2-EB87-0000
SD2-EB88-0000
SD2-EB89-0000
SD2-EB90-0000
SD2-EB91-0000
SD2-EB92-0000
SD2-EB93-0000
SD2-EB94-0000
SD2-EB95-0000
SD2-EB96-0000
SD2-EB97-0000
SD2-EB98-0000
SD2-EB99-0000
SD2-EB1 00-0000
SD2-EB101-0000
EPA ID
96382531
-
-
-
-
96382532
96392703
-
-
-
96382533
-
-
96382534
-
96392704
-.
96392705
96382535
96382536
96382537
96392706
96364552
-
96382538
-
-
96364554
96364553
96374565
96382539
96374566
96374567
96382540
96374568
Field Analysis'
Immunoassay
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
TOC
X
-
-
-
-
X
X
-
' -
-
X
-
-
X
-.
X
-
X
X
X
X
X
X
-
X
-
-
X
X
X
X
X
X
X
X
Grain Size
X
-
-
-
-
X
-
-
-
-
X
-
-
X
-
~
-
-
X
X
X
-
-
-
X
-
-
-
-
-
X
-
-
X
-
Physical and Chemical Analysis"
% Moisture
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- "
_
-
-
-
-
-
-
_
-
-
-
-
PAHs"
X
-
-
-
-
X
X
-
-
-
X
-
-
X
-
X
X
X
X
X
X
X
X
-
X
X
X
X
X
X
X
X
PCBs*
X
- -
-
-
-
-
-
-
-
-
X
-
-
X
-
_
X
X
_
_
_
_
~
_
_
_
_
-
PCDD/PCDF
X
-
-
-
-
-
-
-
- .
-
X
-
-
X
-
_
_
X
_
X
_
_
_
_
_
_
_
_
_
_
_
-
Metals'
Xh
_
-
-
-
_
-
-
X"
X"
_
_
_
*
X"
_
_
_
_
_
_
_
_
_
_
_
_
-
Biological Analysis0
Bioassavs8
X
_
.
_
-
_
X
_
X
_
_
_
_
X
_
X
_
_
_
_
_
_
_
_
_
_
_
_
-
Bioaccum
X
_
_
_
_ '
_
_
_
_
X
_
-_
X
_
_
_
_
X
_
X
_
_
_
_
..
..
H
_
_
_
.
..
_
-
Benthos
X
_
_
_
_
_
_
_
_
_
X
_
_
X
_
_
_
_
X
X
_
»
«.
_
.
«
_
«
_
_
..
-
W-03l8a\ls I
Page 3 of 5
9/28/I999
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 1Summary of Surface Sediment Chemical and Biological Analyses
Sample Number
Weslon ID
SD2-EB102-0000
SD2-EB103-0000
SD2-EB104-0000
SO2-EB105-0000
SD2-EB106-OQOO
SD2-EB1 07-0000
SD2-EB10B-0000
SD2-EB1D9-0000
SD2-EB1 10-0000
SD2-EB11 1-0000
SD2-EB1 12-0000
SD3-EB1 15-0000
SD3-EB1 16-0000
SD3-EB117-0000
SD3-EB1 18-0000
SD3-EB1 19-0000
SD3-EB120-0000
SD3-EB121-0000
SD3-EB122-0000
SD3-EB1 23-0000
SD3-EB1 24-0000
SD3-EB1 25-0000
SD3-EB1 26-0000
SD3-EB127-0000
SD3-EB1 28-0000
SD3-EB129-0000
SD3-EB1 30-0000
SD3-EB131-0000
SD3-EB132-0000
SD3-EB1 33-0000
SD3-EB134-0000
SD3-EB135-0000
SD3-EB1 36-0000
SD3-EB 137-0000
SD3-EB1 38-0000
EPA ID
96374569
96374570
96382541
96382542
96382543
96382544
96382547
96382546
96382549
96382550
96382551
97312350
97312351
97312352
97312353
97312354
97312355
97312356
97312357
97312358
97312359
97312360
97312361
97312362
97312363
97312364
97312365
97312366
97312367
97312368
97312369
97312370
97312371
97312372
97312373
Field Analysis'
Immunoassay
X
X
-
-
-
_
-
_
_
-
-
_
_
-
-
_
_
-
-
-
_
_
_
_
-
_
_
_
_
_
_
_
_
_
-
Physical and Chemical Analysis"
TOC
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
A
X
X
X
A
Grain Size | % Moisture
-
-
X
X
X
X
X
X
A
A
A
-
-
-
-
_
_
-
-
-
.-
_
_
-
-
-
_
_
_
_
_
-
_
_
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
_
_
-
-
-
_
_
-
PAHs"
X
X
X
X
X
X
X
X
A
A
A
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
A
X
X
X
A
PCBS' IPCDD/PCDFI Meiais'
-
-
X
-
X
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
_
-
-
-
-
-
-
X
-
X
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
X"
-
X"
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Biological Analysis'
Bioassavs0 1 Btoaecum | Benthos
-
-
X
-
X
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
X
-
X
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
X
-
X
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
W-ll.)!8a,\ls I
Page 4 of 5
9/28/1999
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 1Summary of Surface Sediment Chemical and Biological Analyses
Sample Number
Weston ID
SD3-EB1 39-0000
SD3-EB140-0000
SD3-EB141-0000
SD3-EB142-0000
SD3-EB 143-0000
SD3-EB 144-0000
SD3-EB145-0000
EPA ID
97312374
97312375
97312376
97312377
97312378
97312379
97312380
Field Analysis1
Immunoassay
-
-
-
-
_
-
~
Physical and Chemical Analysis"
TOC
A
A
A
A
A
X
A
Grain Size | % Moisture | PAHS"
-
-
-
-
-
-
. -
-
-
-
-
-
-
-
A
A
A
A
A
X
A
PCBS* IPCDD/PCDFI Metaisf
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Biological Analysis0
Bioassavs"
-
~
-
_
-
-
Bioaccum
_
-
-
-
_
-
Benthos
_
-
_
-
_
-
_
Background Areas
SD1-BK01-0000
SD1-BK01D-0000
SD1-BK02-0000
SD1-BK03-0000
SD2-BK01-0000
SD2-BK04-0000
SD2-CARR-0000
96162644
96162645
96162646
96162647
96382545
96382546
-
-
-
-
-
-
-
.
X
X
X
X
X
X
-
X
X
X
X
X
X
X1
X
X
X
X
-
-
.
X
X
X
X
X
X
-
X
X
X
X
X
X
-
X
X
X
X
X
X
-
X
X
X
X
X"
X"
-
-
-
-
-
X
X
X
-
-
-
X
X
-
-
-
-
_
X
X
-
"Rapid immunoassay methods for carcinogenic PAHs were specified in the Draft Phase 2 SAP Addendum (WESTON, 1996c); sediment collected at each of
the immunoassay stations was also archived for potential future laboratory analyses.
"Analytical methods were specified in Section 6 of the Phase 1 SAP (WESTON, 1996b).
"Biological testing methods were specified in the Phase 2 SAP Addendum (WESTON, 1996c, 1996d).
"All Phase 1 samples (indicated by WESTON Sample ID prefix "SD1") also analyzed for phenolic compounds and dibenzofuran.
'Aroclors only.
'Metals analyses were limited to aluminum, arsenic, cadmium, copper, iron, lead, mercury, nickel, and zinc.
"Amphipod (Ampelisca abdita) and echinoderm (Dendrastor oxcentricus) acute toxicity tests.
"Mercury only.
'Grain size data consist only of a field screening measurement (of 49% fines).
X: Analyzed.
-: Not analyzed.
A: Sample archived and not analyzed for the Rl.
NA: Apparent gross contamination; sample not analyzed for the Rl based on assumption that PAH contamination would drive cleanup.
Metal, PAH, and PCB analyses performed by EPA Manchester Lab.
PCDD/PCDF analyses performed by Maxim Technologies, Inc.
TOC analyses performed by ARI, Inc.
Grain Size analyses performed by Soil Technology.
Bioassays conducted by Parametrix, Inc.
Benthic enumeration and taxonomic identification performed by Marine Taxonomic Services.
W-OilRaxIs 1
Page 5 of 5
9/28/l9')9
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 2Summary of Shallow Subsurface Sediment
Compositing Scheme and Chemical Analyses
Station
=B03
=B12
EB13
=B16
:B27
sB31
EB32
;B34
=B41
Depth Interval (ft bgs)
Proposed
0-4
0-4
4-8
4-8
8-12
8-12
12-16
12-16
16-20
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
Actual
0-4
0-4
4-8
4.8
8-12
8-12
12-16
12-16
16-20
16-20
0-4
4-8 '
8-12
NR
NR
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
WESTON Sampl*
Number
SD2-EB03-OOOOA
SD2-EB03-1000A
S02-EB03-0040
SD2-EBQ3-1040
SD2-EB03-0080
SD2-EB03-1080
SD2-EB03-0120
SD2-EB03-1120
SD2-£B03-0160
SD2-EB03-1160
SD2-EB1 2-0000 A
SD2-EB12-0040
SD2-EB12-O080
NR
NR
SD2-EB13-OOOOA
SD2-EB13-0040
SD2-EB1 3-0080
SD2-E813-0120
SD2-EB13-0160
SO2-EB15-OOOOA
SD2-EB15-0040
SD2-EB15-0080
SD2-EB1S-0120
SD2-EB1S-0160
SD2-EB27-OOOOA
SD2-EB27-0040
SD2-E827-0080
SO2-EB27-0120
SD2-EB27-0160
S02-EB31-OOOOA
SD2-EB31-0040
S02-EB31-0080
SD2-EB31-0120
SD2-EB31-0160
SD2-EB32-OOOOA
SD2-EB32-0040
SD2-EB32-0080
SD2-EB32-O120
SD2-EB32-0160
SD2-EB34-OaOOA
SO2-EB34-0040
SD2-EB34-0080
SD2-6B34-0120
SO2-EB34-0160
SO2-6B41-OOOOA
SD2-EB41-O040
SD2-EB41-O080
SO2-EB41-0120
SD2-EB41-0160
EPA Sample
Number
96392707
96392708
96392709
96392710
96392711
96392712
96392719
96392720
96392721
96392722
96404900
96404901
96404902
NR
NR
96404905
96404906
96404907
96404908
96404909
96392723
96392724
96392725
96392726
96392727
96392734
96392735
96392736
96392737
96392738
96404910
96404911
96404912
96404913
96404914
96404915
96404916
96404917
96404918
96404919
96404920
96404921
96404922
96404923
96404924
96404925
96404926
96404927
96404928
96404929
Analysis*
£
X
X
X
X
X
X
X
X
X
X
X
X
X
NR
NR
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
A
X
X
X
X
X
X
X
X
A
A
X
X
X
X
X
I Phenols
-
-
-
_
-
_
-
-
-
-
_
-
-
-
-
X
X
X
X
X
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
_
_
-
-
-
-
_
-
-
X
X
X
X
X
Dibenzofufan
-
-
-
-
-
-
-
-
-
-
-
-'
-
-
-
X
X
X
X
X
-
-
-
-
-
-
-
-
-
-
-
-
_
-
-
-
_
_
-
-
-
-
-
-
-
X
X
X
X
X
I
-
-
-
-
-
-
-
-
-
-
-
-
-
-
X
X
X
X
X
-
-
_
-
-
-
-
-
-
-
-
-
-
-
-
-
_
_
-
-
-
-
-
-
-
X
X
X
X
X
M
-
-
-
-
-
-
-
-
-
-
_
-
-
-
-
X
X
X
X
X
-
-
-
-
-
-
-
_
-
-
-
-
-
-
-
-
-
-
-
_
-
-
-
-
-
X
X
X
X
X
8
X
X
X
X
X
X
X
X
X
X
X
X
X
NR
NR
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
A
X
X
X
X
X
X
X
X
A
A
X
X
X
X
X
Grain Size
-
-
-
_
-
-
-
-
-
-
_
-
-
-
-
X
X
X
X
X
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
X
X
X
X
X
t
£
-
-
-
_
-
-
-
-
_
_
(X(G2)]
(X(G2)J
_
-
-
(X(G2)]
(X(G2)]
-
-
-
[X(G1)J
fX(G1))
-
-
-
|X(G1)]
(X(G1)]
-
-
-
(X (G2)J
(X(G2)|
-
-
-
fX(G2)|
(X(G2)1
-
-
-
(X(G2)]
(X(G2)]
-
-
-
(X
-------
1
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 2Summary of Shallow Subsurface Sediment
Compositing Scheme and Chemical Analyses
Station
EB42
B49
B66
=B72
B78
EB87
B104
£113
Group 1
Group 2
Depth Interval (ft bgs)
Proposed
0-4
4-8
8-12
12-16
16-20
0-4
4-8 .
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-6
8-12
12-16
16-20
4-8
8-12
4-8
8-12
Actual
0-4
4-8
NR
NR
NR
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-18.7
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-8
8-12
12-16
16-20
0-4
4-7
NR
NR
NR
4-8
8-12
4-8
8-12
WESTON Sample
Number
S02-EB42-OOOOA
SD2-EB42-0040
NR
NR
NR
SD2-EB49-OOOOA
SO2-CB49-0040
SD2-EB49-0080
SD2-GB49-0120
SD2-EB49-0160
SD2-EB66-OOOOA
SD2-EB66-0040
SD2-EB66-0080
SD2-E866-0120
SD2-EB66-0160
SO2-EB72-OOOOA
SD2-EB72-0040
SO2-EB72-0060
SO2-EB72-0120
SD2-EB72-0160
SD2-EB78-OOOOA
SO2-EB78-0040
SD2-eB78-0080
SO2-EB78-0120
SD2-EB78-0160
SD2-EB87-OOOOA
SD2-EB87-0040
SD2-EB87-0080
SD2-EB87-0120
SD2-EB87-0160
SO2-EB104-OOOOA
SD2-EB104-0040
SD2-EB104-0080
SD2-EB1 04-0120
SD2-EB1 044)160
SO2-EB113-OOOOA
SD2-EB1 13-0040
NR
NR
NR
SD2-EBC01-0040
SO2-EBC01-O080
SD2-EBC02-0040
SD2-EBC02-0080
EPA Sample
Number
96404930
96404931
NR
NR
NR
96392728
96392729
96392731
96392732
96392733
96404935
96404936
96404937
96404938
96404939
96404940
96404941
96404942
96404943
96404944
96404945
96404946
96404947
96404948
96404949
964O49SO
96404951
96404952
96404953
96404954
96404955
96404956
96404957
96404958
96404959
96404960
96404961
NR
NR
NR
96392739
9640496S
96404966
96404967
Analysis*
vt
I
X
X
NR
NR
NR
X
X
X
X
X
X
X
X
X
X
X
X
X
A
A
X
X
A
A
A
X
X
X
X
A
X
X
A
A
A
X
X
NR
NR
NR
_
_
Phenols
_
_
-
-
_
-
-
_
_
-
-
-
-
-
-
-
-
-
-
_
-
_
_
-
-
-
_
-
-
-
_
_
_
_
-
_
_
_
-
-
_
_
Dibenzofuran
_
-
-
-
-
_
_
_
_
-
-
-
-
-
-
-
-
-
_
_
-
_
_
_
-
-
_
_
_
-
_
_
_
_
-
_
_
_
-
-
_
_
J2
a
£
-
-
-
-
-
_
_
_
-
-
-
-
-
-
,_
_
-
_
_
_
_
_
_
_
-
-
_
_
-
_
_
_
_
-
_
_
_
-
-
_
_
&
1
_
-
-
-
-
-
_
_
_
-
_
_
-
_
_
_
-
_
_
_
_
_
_
-
_
_
_
-
_
_
_
_
_
_
_
-
-
_
_
g
X
X
NR
NR
NR
X
X
X
X
X
X
X
X
X
X
X
X
X
A
A
X
X
A
A
A
X
X
X
X
A
X
X
A
A
A
X
X
NR
NR
NR
_
_
Grain Size
_
_
-
--
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
-
_
_
_
_
_
_
_
_
-
-
_
_
I
_
[X (G2)l
-
-
_
-
[X(G1)]
[X(G1)]
_
_
_
IX(G2)]
{X]
_
_
PC (G2)]
(X (G2)]
_
_
_
(X(G2)]
fX(G2)]
_
_
_
PC (G2)]
PC(G2)]
_
_
_
(X(G2)]
PC
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 3Summary of Deep Subsurface Sediment Field and Laboratory Analyses
Station
EB14
EB16
Depth Interval
(ftbgs) "
0-3
3-6
8-10
12-14
20-22
22-24
24-26
26-28
28-30
30-32
32-34
42-44
60-62
62-64
64-66
66-68
68-70
70-72
72-74
74-76
76-78
78-80
8C--82
82-84
84-85
0-3
3-6
12-14
20-22
22-24
24-26
26-28
28-30
30-32
32-34
52-54
60-62
62-64
64-66
66-68
68-70
70-72
72-74
74-76
76-78
78-80
80-82
82-84
84-85
WESTON Sampte
Number
SDEB14-OOOO
SDEB14-0030
SD2-EB14-0080
SD2-EB14-0120
SD2-EB14-0200
SD2-EB14-0220
SD2-EB1 4-0240
SD2-EB14-0260
SD2-EB14-0280
SD2-EB1 4-0300
SD2-EB14-0320
SD2-EB14-0420
SD2-EB1 40600
SD2-EB14-O620
S02-EB14-0640
SD2-EB14-O660
S02-EB14-0680
SD2-EB1 4-0700
SD2-E81 4-0720
S02-E814-0740
SD2-EB1 4-0760
SD2-EB14-0780
SD2-EB14-O800
SD2-EB1 4-0820
SD2-EB1 4-0840
SDEB16-0000
SOEB1 6-0030
SD2-EB16-O120
SD2-EB16-O2OO
SD2-EB1 6-0220
SD2-EB16-0240
SD2-EB1 6-0260
S02-EB1 6-0280
SD2-EB16-0300
SD2-EB1 6-0320
SD2-EB1 6-0520
SD2-EB16-0600
SD2-EB16-0620
SD2-EB1 6-0640
SD2-EB16-0660
SD2-EB16-0680
SD2-EB16-0700
SD2-EB16-0720
SD2-EB1 6-0740
SD2-EB16-0760
SD2-EB1 6-0780
SD2-EB1 6-0800
SD2-EB16-0820
SD2-EB1 6-0840
EPA Sample
Number
-
-
-
-
96464640
-
-
96464641
-
-
-
-
-
-
-
-
-
96464647
-
-
-
-
-
-
96464648
-
-
-
-
-
-
Field Analysis"
UV
-
-
-
-
X
-
X
X
X
X
X
-
X
-
X
-
X
X
-
-
-
X
X
-
X
-
X
-
-
X
-
X '
. -
X
-
X
-
X
-
-
-
-
Immuno-
assay
-
-
-
-
-
-
-
X
-
-
X
X
X
X
X
X
-
-
-
-
-
-
-
-
-
-
-
X
-
X
X
X
X
X
X
X
X
X
X
X
X
X
Laboratory Analysis"
Eng.
Param.c
X
X
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
X
X
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
PAHs
-
-
-
-
A
A
A
A
A
A
A
_
A
A
A
-
A
A
A
-
A
A
A
A
A
-
-
A
A
A
A
A
A
-
-
-
A
A
A
A
A
A
A
A
A
A
A
A
A
TOG
-
-
A
A
-
-
-
A
-
-
X
A
-
-
-
A
-
X
-
A
-
-
-
-
-
-
A
-
-
-
-
A
-
X
A
-
A
-
-
-
-
X
-
-
-
-
-
-
Grain
Size
-
-
A
A
-
-
-
A
-
-
X
A
-
-
A
-
X
-
A
-
-
-
-
-
.-
-
A
-
-
-
-
A
-
X
A
-
A
-
-
-
-
X
-
- '
-
-
-
-
99-031S».x)s3
Page 1 of2
-------
1
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 3Summary of Deep Subsurface Sediment Field and Laboratory Analyses
"Analytical methods were discussed in the revised Phase 2 SAP Addendum (WESTON. 1996d).
Analytical methods were specified in the Phase 1 SAP (WESTON, 19966).
'Engineering parameters consisted of Atterburg limits, engineering classification, specific gravity, grain size, percent
moisture, triaxial shear (consolidated and unconsolidated), consolidation tests, and unconfined compressive strength
X: Analyzed.
: Not analyzed.
A: Archived; not analyzed for the Rl.
99-0318a.xIj3
Page 2 of2
9/28/I999
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 4Summary of Clam and Fish Tissue Chemical Analyses
Sample Number
Weston ID
EPA ID
Media
Chemical Analysis
Lipid
>SR Marine Sediments Unit
CTI-EB49-0000
CTI-EB60-0000
CTI-EB67-OQOO
CTI-EB77-0000
CTI-EB80-0000
CTl-EBSS^XXJO
CTI-EB87-0000
CTI-EB1 04-0000
CTI-EB106-0000
FT2-WEST-ES-WB-R2
FT2-WEST-ES-WB-R4
FT2-WEST-ES-WB-R5
FT2-NORTH-ES-WB-R1
FT2-NORTH-ES-WB-R2
FT2-NORTH-ES-WB-R3
FT2-WEST-ES-FT-R1
FT2-WEST-ES-FT-R3
T2-WEST-ES-FT-R4
=T2-NORTH-ES-FT-R1
FT2-NORTH-ES-FT-R2
FT2-NORTH-ES-FT-R3
96454330
96454332
96454333
96454334
96454335
96454336
96454337
96454338
96454339
96382503
96382504
96382505
96382509
96382510
96382511
96382500
96382501
96382502
96382506
96382507
96382508
Background Areas
CTI-BK01-0000
CTI-BK04-0000
FT2-ALKI-ES-WB-R1
FT2-ALKI-ES-WB-R2
FT2-ALKI-ES-WB-R3
FT2-MAGL-ES-WB-R1
FT2-MAGL-ES-WB-R2
FT2-MAGL-ES-WB-R3
FT2-ALKJ-ES-FT-R1
FT2-ALKI-ES-FT-R2
FT2-ALW-ES-FT-R3
FT2-MAGL-ES-FT-R1
FT2-MAGL-ES-FT-R2
FT2-MAGL-ES-FT-R3
96454340
96454341
96382521
96382522
96382523
96382515
96382S16
96382S17
96382518
96382S19
96382520
96382512
96382513
96382514
Clam Whole Body6
Clam Whole Body*
Clam Whole Bod/
Clam Whole Bodyc
Clam Whole Bod/
Clam Whole Bod/
Clam Whole Bod/
Clam Whole Bod/
Clam Whole Bod/
Fish Whole Bod/
Fish Whole Bod/
Fish Whole Bod/
Fish Whole Bod/
Fish Whole Bod/
Fish Whole Bod/
Fish Fillet"
Fish Fillet"
Fish Fillet"
Fish Fillet"
Fish Fillet"
Fish FHIet"
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
PAHs
X
X
X
X
X
X
X
X
X
-
-
-
-
. -
-
-
-
-
-
-
-
Clam Whole Bod/
Clam Whole Bod/
Fish Whole Bod/
Fish Whole Bod/
Fish Whole Bod/
Fish Whole Bod/
Fish Whole Bod/
Fish Whole Bod/
Fish Fillet"
Fish Fillet"
Fish Fillet"
Fish Fillet"
Fish Fillet"
Fish Fillet"
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-
-
-
-
-
-
-
-
-
-
-
-
PCBs°
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Diox/Fur
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Mercury
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Analytical methods were specified in Ihe Phase 1 SAP (WESTON, 1996b) and Draft Phase 2 SAP Addendum
(WESTON. 1996c).
bAroclors only.
'Macoma nasuta exposed in laboratory to site-collected sediment.
"English sole collected from the site,
X: Analyzed.
-: Not analyzed.
Lipid, PAH. PCB, and Mercury analyses performed by EPA Manchester Lab.
Dioxin/Furan analyses performed by Maxim Technologies, Inc.
99-03 ISa.xfa 4
Page 1 of 1
9/2 & 1999
-------
1
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 5SMS and AET Chemical Screening Criteria for Sediment COCs
Chemical
Sediment Management
Standards8
SQSD
CSL/MCULC
Apparent Effects Threshold"
LAET
2LAET1
Organics (ug/kg)
Acenaphthylene
Acenaphthene
Anthracene
Benz(a)anthracene
Benzo(a)pyrene
Total Benzofiuoranthenes8
Benzo(g,h,i)perylene
Chrysene
Dibenz(a,h)anthracene
Dibenzofuran
2 ,4-Dimethylphenol
Fluoranthene
Fluorene
Total HPAH
lndeno(1 ,2,3-cd)pyrene
Total LPAH
2-Methylna phthalene
2-Methylpheno!
4-Methylphenol
Naphthalene
Total RGBs'
Pentachlorophenol
Phenanthrene
Phenol
Pyrene
66.000e
16,000'
220,000"
110,000"
99,000°
230,000°
31.000°
110,000°
12.000°
15,000°
29h
160.000°
23,000°
960.000°"'
34,000°
370,000d'°
38,000°
63h
670h
99.000°
12,000°
360h
100,000°
420h
1,000,000°
66,000°
57,000°
1,200,000°
270,000°
210,000°
450.000°
78,000°
460,000°
33,000°
58,000°
29h
1,200.000°
79,000°
5,300,000°-'
88,000°
780,000d'°
64,000°
63h
670h
170,000°
65.000°
690h
480.000°
1,200h
1,400,000°
1,300h
500h
960h
1,300"
1,600h
3.200h
670h
1,400h
230h
540"
29h
1,700h
540"
12,000"
600h
5200h
670h
63h
670h
2,100h
130"
360h
1,500h
420h
2,600h
1,300h
730h
4,400h
1,600h
3,000h
3,600h
720h
2,800h
540h
700"
72h
2,500h
1,000h
17,000"
690"
13,000h
1,400"
72"
1,800"
2,400h
1,000"
690"
5,400"
1,200"
3,300h
Inorganics (mg/kg)
Arsenic
Cadmium
Chromium (total)
Copper
57h
5.1h
260h
390h
93h
6.7h
270h
390h
57h
5.1h
260h
390h
93"
6.7"
270"
530h
99-0318a.xls
Page 1 of2
9/28/I90Q
-------
1
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 5SMS and AET Chemical Screening Criteria for Sediment COCs
iment Management
Standards8
Apparent Effects Threshold1"
CSL/MCUL
=
530h
m^B^n.
0.59h
960
'Chapter 1 73-204 WAC.
bSediment Quality Standards.
"Cleanup Screening Levels and Minimum Cleanup Levels.
°"he (°"°Wi"9 """PO""*- naphthalene. acsnaphlhytene. aceoapMhsne
represent me
m'hrace"e: lhe LPAH
'Normalized to total organic carbon content.
'This value represents the sum of the following compounds: fluoranthene. pyrene, benz(a)anthracene
chrysene. total benzofluoranthenes. benzo(a)Pyrene. indeno(1,2.3 cd)pyrene. diben2(a.h)anthracene'
and benzo(g,h,i)perylene; the HPAH criterion does not represent the sum of the criteria values for the
individual compounds.
"Sum of the concentrations of the "b," "j." and "k" isomers.
"Dry-weight basis.
'Lowest Apparent Effects Threshold.
'Second-lowest Apparent Effects Threshold.
"Barricketal., 1988.
*This value represents the sum of detected Arodors.
99-03l8axls
Page 2 of2
9/28/I999
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 6Surface Sediment Background Concentrations for Selected Contaminants"
Compound
2,3,7, 8-TCDD Eqiv. (ng/kg DW)
2,3,7,8-TCDD Eqiv. (ng/kg TOCN)
Total LPAHs (ug/kg DW)_
Total LPAHs (ug/kg TOCN)
Total HPAHs {ug/kg DW)
Total HPAHs (ug/kg TOCN)
Total PAHs (ug/kg DW)
Total PCBs (ug/kg DW)
Total PCBs (ug/kg TOCN)
Concentration
Phase 1
BK01
0.619
82.5
3,463
461,733
14,969
1,995,867
15,007
5.8
773
BK01D" | BK02
0.518
55.1
1,008
107,191
3,173
337,511
3,485
10.7
1,138
4.029
366.3
286
25,991
1,528
138,891
1,252
50.0
4,545
BK03
0.184
NA
36
-
38
-
38
2.3
-
Phase 2
BK01
0.290
12.100
847
35,292
3,608
150,312
3,554
23 U
23 U
BKD4
0.670
95.700
644
91,957
1,331
190,114
1,714
199.0
28,429
Average
1.052
122.340
1,044
144,433
4,104
562,539
1,052
46
6,979
See Figure 7 for background locations.
"Methods used for deriving and summing 2,3,7,8-TCDD equivalents are described in Rl Appendix F (WESTON 1998).
"Field replicate at Station BK01.
DW- Dry-weight.
TOCN: Normalized to total organic carbon (TOC) content.
NA: Normalization not appropriate; TOC content less than 0.5 percent.
Page I of I
-------
Paclnc Sound Rtsourns Record of DectelonMarfnt Sedlmonla Unit
Tabto 7Simimiry Statbtkt for Surftc* Sediment COCj
CWMHusnl
BenzolrapMlHlene
OTHER SVOC.ftjg/k,)
S££" ,
lot
SliUoni
Anllyud
106
IOC
106
106
106
*ol
OMKttd
VoVoi
ioe
ioe
106
106
106
106
106
IDS
106
106
106
106
30
46
42
Frequency of
O«lKI»n(K)
5s
100
99
100
100
100
too
100
100
100
100
100
100
93
59
70
is
68
100
90
100
100
100
100
Minimum
38
10
20
21
96
42
248
164
61
100
177
M
45
4.2
1B
T!Z
158
31
115
24 f
Tg? ]
DIY.W.W.
Midnum
15.700
5.3SO
397.000
211.000
549.000
1.750.000
2.M8.080
2,060.000
1.140.000
392,000
520.000
302.900
114.000
34,400
10,700
29.600
<. 590.600
1,310
601
6.770
380
3,980
62,«00
<143
3.090
4,570
635
1.340
156
Minimum
EB09
EB13
EB13
EBI3
EB09 "~
EBO»
EB02
EBB7
EB06 1
~i^~T
MJnimuni
1 3.324
676
1,448
2.133
4.552
21.990
19.09$
16,048
11.714
16.236
27,333
12.657
6.180
1.029
5,239
117.257
1,119
1,895
3.923 1
102
TOC-Nomubod
I 2.610.162
62.174
766.234
760.000
3.488.750
1.900.000
6.868.052
__8,695,652
6.9S6.522
1.891,304
1.860.870
1.743.476
726,067
215,658
177.826
22.346.522
| 646.753 1
800.000
78.162
11.819
EB27
E805
EBI9
EB05
ED27
EB27
EB27
EB27
EB27
EB27
EB27
EB27
6B27
EB27 .
EBO* I
EBOS -
»o(Enfc»
Scmnli
59
4
aa
74
64
17
59
17
26
32
lExCMdng
ngCritKlt
38
4
36
17
36
13
Figqoancy of EicaftJanc*
-------
Pacific Sound Resources Record of Decision-Marine Sediments Unit
Table 7Summary Statistics for Surface Sediment COCs
-: Not applicable.
<. Not detected at dry-weight detection limit shown.
ER = E,
-------
Pacific Sound Rtsourc«s Rocord of DtetttonMario* Std»m9nt» Unit
Tabl« 8Summ«ry SUIIiUca for Shtllow Subttuftc* (0 to 20 tot bfli) Stdtminl COCs
CWUMIMM
'AHaluoftq)
1jj>hmaiei»
teenapMhYtena
Kcenaphlharw
luoren*
Ptwianthrvno
Anthracene
Foul LPAH
Fluoranlherw
Pyreno
Befttofajanihracena
Chiysono
Total Benzofluwanttienas
Banzofajpyrena
lndeno(1.2.3.cd)pyrone
Dit»nz|a.hjanttiraceno
Benzofg.h.ijperytene
ran HPAH
Mitelnylnaphlhaleiw
OTHER SVOCi Ivg/ko)
!.4.0«iiBthylpheiio(
2-Melhylf)henal
4-Methytplwnol
'entacWOfoplwnd
Dtianol
2-CMoronHphthaleno
Relon.
>CBi liig/kg)
rolal PCBj
(otCon
Inlxvai]
Analpad
U
OS
85
85
OS
65
05
15
65
03
es
OS
65
OS
65
es
65
65
10
10
10
10
10
10
49
49
39
At
10
lot
OOKUd
Valuta
M
39
54
51
eo
01
03
57
02
45
40
51
40
43
34
42
62
61
2
0
3
0
0
8
1
30
57
49
Fnqgoncyof
D.1«C*0(S]
19
00
13
Tl
92
94
97
BS
95
19
75
70
02
00
52
05
95
94
20
0
30
0
0
80
2
61
97
100
DetKMCVKHlnecm
Dry-VWgN
Mrimm
40
14
21
50
42
1.2
12
7.0
4.0
4,7
2.0
36
0-1
2.7
1.7
2.9
4.0
1.2
316
<9.1
107
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 8-Summary Statistics for Shallow Subsurface (0 to 20 feet bgs) Sediment COCs
'Average ERs catenated using only thoss individual ER« >1.0.
Frequonaei basad on lol«l nimbw ol «l«llon« mnynd.
^M *"''"* ""n>Km *"'"*' "" ram|Mred "*> "*r' ""«" TOC conlM M5M. ih. rano, dewmlMd » b. .ppmpn.1. tbr nom,ate,lion
Page 2 of 2
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 3Summary of Human Health Chemicals of Concern and Fish Tissue Exposure Point Concentrations
Scenario Tlmo(ram»: Current (Baseline)
Modlum: Fish Tissue
Exposure Modlum: Fish Fillet Tissue
Exposure
Point
Ingeslion of
Fish Fillets
Chemical of
Concern
Aroclor 1242
Aroclor 1254
Aroclor 1260
Total PCB
Total 2.3.7.8-TCDD (Equiv.)
Concentration Detected'
Minimum
13
SA
51
105
0.00007
Maximum
52
330
140
492
0.00031
Units
ug/kg-WW
ugfcg-WW
ug/kg-WW
ug/Xg-WW
ug/kg:WW
Frequency ol
Detection
- 316
em
616
616
2/3
Exposure Point
Concentration"
553
672
297
1329
0.0521
Exposure Point
Concentration Units
ug/kg-WW
ug/Kg-WW
ug/kg-WW
ug/Kg-WW
ug/kg-WW
Statistical
Measure
90th Percentila
90th Percentile
90th Percentile
901h Percentile
90lh Percentile
"Based on 6 composite fish samples collected from the site.
"Site-wide exposure concentration estimated (ram surface sediment concentrations using a biota-sediment accumulation factor.
WW: Wet-weight.
'W-03l8b.xls')
Page 1 of 1
-------
r^!"C.?°"nl?lS.°Urces Record °f Decision-Marine Sedim,
Table 10Summary of Human Health Chemicals of Con&
ients Unit
ern and Shellfish Tissue Exposure Point Concentrations
Scanarlo Tlmeframe: Current (Baseline)
Exposure Medium: Clam Whole Body Tissue
|Based on 9 composite clam samples from laboratory bioaccumulatkm study
~^
Page I of I
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 11Human Health Cancer Toxicity Data Summary
Pathway: Ingestion of Fish and/or Shellfish
Chemical of
Concern
Carto azote
Total cPAHs (BaP cquiv )
Total PCBs
2.3.7,8-TCDO (Equiv.)
Oral Cancer
Slope Factor
2.00E-02
7.30E+00
2.00E*00
1.56E+05
Slope Factor
Units
(mg/kgl/day
(mg/kgVday
(mg/kg)/day
(mg/kgVday
Weight of Evidence/
Cancer Guideline Description
B2
B2
B2
B2
Source
HEAST
IRIS
IRIS
HEAST
Date
1997
1997
1997
1995
IRIS; Integrated Risk Information System, U.S. EPA.
HEAST: Health Effects Assessment Summary Tables.
82: Probabte human carcinogen - Indicates sufficient evidence in animals and inadequate or no evidence in humans.
Page I of 1
-------
Pacific Sound Resources Record of Decision-Marine Sediments Unit
Table 12-Human Health Non-Cancer Toxicity Data Summary
Pathway: Ingestion of Fish and/or Shellfish
^Uncertainty factor; Modifying factor = Nona; Confidence in value * Low
Fluorantfiene and fluorene used as surrogate for naphthalene.
IRIS: Integrated Risk Information System, U.S. EPA,
W-03l8h
-------
Pacific Sound Resource! Record of DecisionMarina Sediments Unit
Table 13Rlik Parametirt
Ish ind Shrill) sn Consumption Exposure Scenario Piramittre
Parameter
elfish)
IR
EF
ED
(IPS)
f{spectes)
Kulil'ianon)
BW
ATcancer
ATnoncancei
RlOo
CSFo
HQ
CR
THQ
TCR
CF1
CF2
CF3
PwamiterDesertptxxi
concentration ol contaminant in fish (ug/xg)
human daily ingeittm rale 01 fish (g/dty)
human exposure frequency lo scenario Involving consumption o( (i sh (dayiryr)
human exposure duration lo scenario kiroMng consumption of (ish (yews)
fraction ol fish consumed that are obtained from Puget Sound (unttless)
fraction ol types fislvsheilfHh species consumed Hut am available at the silo (unites!)
Iraction the site represents ot total sites utilized by Individuals in Pugel Sound lo han/esl
Hih/shelinsh (unities!)
body weight ol person (kg)
averaging lime over which umnogonic exposure should be consMend-utuany considered
as a lifetime (years)
averaging lime over which noncarcinogenlc exposure should be considered-usuaily
considered as equal lo the exposure duration (years)
oral noncancer reference dose considered an exposure threshold (ms/kg-day)
oral cancer slope factor expressing carcinogenic toxicity of contaminant (kg-day/mg)
hazard quotient expressing a ratio of exposure to the reference dose (unldojs)
incremental cancer risk expressing probability of developing cancer over a lifetime from given
exposure (unilless)
target hazard quotient-predetermined value not lo be exceeded (unitless)
target cancer risk-predetermined value not to be exceeded (unities!)
converts chem cone In fish from ug lo mg (mgrug)
converts mgeslion rale Iron g lo kg (kg/g)
converts avg time from years lo days (days/yr)
Exposure via Fish Coraumptxm
AduKRME
MultCTE
CMdflME
CMdCTE
Exposure via ShtCfuh Coruumplxm
AduHRME
Adult CTE
CriWRME | ChMCTE
Chemtcal Specific
1596
175
24
0.21
1
1
TO
70
24
105
175
24
0.21
1
1
70
70
24
0495
175
6
021
1
1
15
NA
S
04S5
175
6
021
1
1
15
NA
e
91.56
175
24
0.«7
0.48
1
70
70
24
805
175
25
067
0.34
1
70
70
24
881
175
8
087
049
1
15
NA
a
018
175
8
007
034
1
15
NA
8
Chemical Specific
Chemical Specific
Chemical Specific
Chemical Specific
1
1.00E-08
1.00E-03
1.00E-03
385
1
1.00E-06
1.00E-03
1.00E-03
365
1
1.00E-06
1.00E-03
1.0aE-03
365
1
1.00E-06
1.00E-03
1.00E-03
385
1
1.00E-06
0.001
0.001
365
1
1.00E-06
0.001
0.001
305
1
1.00E-06
0.001
0.001
385
1
1 OOE-06
0.001
0.001
365
Sediment/Tissue Concentration Parameter!
Parameter I Parameter Descrlpllon
c(sedimenl)
c(fish)
Wipid)
BSAF
foe
concentration of contaminant In sediment (ug/kg-DW)
concentration of contaminant in fish (ug/kg)
fraction of lipid in fish (unitless)
biota sedimenl accumulation factor [(ug-contam/g-lipld)/(ug-contiim/g-OC)] for transfer of
contaminant from sediment to fish
traction of organic carbon in the sediment (unitless)
FUh Value
chem spec
chem spec
0.017
chem spec
0.0183
Shellfish
Value
chem spec
chem spec
0.0026
chem spec
0.0183
Page I of2
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 13Risk Parameters
Equations tor calculating risk
HQ = __ c(fish) x IR » EF x ED X (|PS) x flspedea) x f(ulfa) x CF1 x CF2
BW x ATnoncancer x CF3 x RfDo
CR - c(lish) x IRrwa x EF «(EDatEDc) x r(PS) x flspecies) x (jullte) x CF1 x CF2 x CSFo
BWtwa x ATcancer x CF3
c(lish) =
C[«d)xf(llpld)»BSAF
IDC
Equations tor calculating risk-based concentrations
RBC(fish) = THQxBW x ATnoneancef X CF3 x RfDo
RBC(fish) =
RBC(sed) =
IR x EF x ED x f(PS) x HSpedes) x f(utllz) x CF1 X CF2
TCR x BWIwa X ATcancer X CF3
IRtwa x EF x (EDctEDa) x t(PS) x f(spedM) x ((ulllz) x CF1 x CF2 x CSFo
focxRBC(fiah)
l(lipld)xBSAF
Time-waighted average values over total svposuw duration
IRlwa = QRaduli x EDaault) t (iRchlM x EDcliild)
(EDclilld * EOadull)
jBWadull x EDadull) > (BWchild x EDchild)
SUMMARY INTAKE FACTORS
RME
CTE
Cancer
941E-09
682E-10
Fish
Adull
Noncancer
2.30E-08
1.51E-09
Child
Noncancer
3.12E-09
3.12E-09
Shellfish
Cancer
8.57E-08
5.32E-09
Adull
Noncancer
2.06E-07
1 31E-08
Child
Noncancer
903E-oa
1 31E-09
RBC(l\sh>*(THQ'R
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 14Human Health Risk Characterization Summary - Carcinogens
Scenario TImeframe Current (Baseline)
Receptor Population: Tribal Fisher (RME)
Medium
Fish
Shellfish
attS.
Shellfish
Exposure
Medium
Fish Fillet
Clam Whole
Body
Fish Fillet &
Clam Whole
Body
Exposure
Point
Ingestion
Ingestion
Ingestion
Chemical of
Concern
Benzo(g,h.i)perylene
Phenanthrene
Pyrene
Total (BaP) Equivalent
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fiuoranthene
Benzo(a)pyrene
ndeno(1 ,2,3-cd)pyrene
Dibenz(a,h)anthracerte
Total PCBs
Total 2.3.7.8-TCDO (Equiv.)
Benzo(g,h,l)perylene
Phenanthrene
Pyrene
Total (BaP) Equivalent
3enzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
BenzoOOfluorantnene
3enzo(a)pyrene
ndeno(1 ,2,3-cd)pyrene
3ibenz(a,h)anthracene
Total PCBs
Total 2.3,7.8-TCOD (Equiv.)
Benz
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 15Human Health Risk Characterization Summary - Non-Carcinogens
Scenario Timefracne: Current (Baseline)
Receptor Population: Tribal Fisher
Receptor Age: Adult and Child
Medium
Shellfish
Fish 4
Shellfish
Exposure
Medium
Clam Whole
Body
Fish Fillet &
Clam Whote
Body
Exposure
Point
Ingestion
Engestion
Chemical of
Concern
Phenanthrene
Pyrene
Total (BaP) Equivalent
Benzo{a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
lndeno(1.2,3-cd)pyrene
Oibenz(a,h)anthr3cene
Total PCBs
Total 2.3,7.8-TCDD (Equiv.)
Benzo(g.h,i)perylene
Phenanthrene
Pyrene
Total (BaP) Equivalent
Benzo(a)anthracene
Chrysene
Benzc(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
lndeno(1,2,3-cd)pyrene
Oibenz(a,h)anthracene
Total PCBs
Total 2,3,7,8-TCDD (Equiv.)
Primary Targe
Kidney
Kidney
Shellfish Total Risks
Benzo(g,h,i)perylene
Phenanthrene
Pyrene
Total (BaP) Equivalent
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)nuoranthene
Bert20(a)pyrene
ndeno<1 ,2,3-cd)pyrene
Dibenz{a.h)anthracene
Fotal PCBs
Total 2.3.7.8-TCDD (Equiv,)
Kidney
Fish and Shellfish Total Risks
Non-Carcinoaenic Hazard Quotient
MA
NA
NA
NA
NA
NA
NA
NA
NA
MA
NA
1.5
NA
NA
NA
0.0
NA
NA
NA
NA
NA
NA
NA
NA
2.1
NA
2
MA
NA
0.0
NA
NA
NA
NA
NA
NA
NA
NA
3.6
NA
4
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
0.2
NA
NA
NA
0.0
NA
NA
NA
NA
i(A
NA
NA
NA.
0.9
NA
1
NA
NA
0.0
NA
NA
NA
NA
NA
NA
NA
NA
1.1
NA
NA: Not available.
99-0318b.xls IS
Page 1 of 1
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 16Ecological Exposure Pathways of Concern
Exposure
Medium
Sediment
Sensitive
Environment
Flag (V or N)
N
Receptor
Benthic
Organisms
Shellfish
Flat Fish
Endangered/
Threatened Species
Flag (Y or N)
N
N
N
Exposure
Routes
Sediment digestion,
respiration, direct contact
with chemicals in
sediment
Ingestion of contaminated
sediment and prey,
respiration, direct contact
with chemicals in
sediment
Ingestion o( contaminated
sediment and prey,
respiration, direct contact
with chemicals in
sediment
Assessment
Endpoinls
Benthic invertebrate
health
Shellfish population
health
Fish population health
Measurement
Endpomts
- Abundance and richness of
individual species, major taxonomlc
groups (crustaceans, molluscs.
porychaeles), and total organisms
- Community structure evaluation
Swarte's Domininance Index
- Toxlcity of sediment to amphipods
(AmpeliscB ebdila )
- Toxlcity of sediment to echinodemn
embryos (Dandraslar oxcen(ricus)
- Toxlcity of sediment to clams
(Macomanasuta)
Chemical concentrations of
bloaccumulative COCs in whole
body clam tissues
- Chemical concentrations of
bloaccumulative COCs In whole
body English sole tissues
- Malernatfegg TCDD transfer model
1«MO I Kb \l» 16
Page 1 of 1
9/28/1999
-------
T h, <7 n PacifIcSoundRe80urees Record of Decision-Marine Sediments Unit
Table 17-Occurrence, Distribution and Seiect.on of Ecoiogica, Chemica,, oftoncL in Sediment
Exposure Medium: Sediment (Benthic Invertebrates)
naximum detected concentration above the sample quantitation limit (SQL)
alized to total organic carbon (TOC) content.
^Based on average of detected values only.
"Hazard quotient (HQ) is defined as Maximum Concentration/Screening Toxlcily Valua
ppb: part-per-billion (ug/kg).
NA: Not available.
SMS SQS: Sediment Management Standards Sediment Quality Standard.
17 Page 1 of 1
W28/I9W
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 18Occurrence, Distribution and Selection of Ecological Chemicals of Concern In Shellnsh
Exposure Medium: Clam Whole Body Tissue
Chemical of
Potential Concern
Mercury
AcenapMhyJene"
"icenaphlheno"
Anthracene0
Benzofa)anlhracene°
Benzo(a}pyrene"
Benzo[b)fluoranlhene°
Benzolg.h.ijperylene"
Benzo(k)nuoranttiene°
2-Chloronaphthalene°
Chrysene"
Dibenz(a,h)anthracene°
Tluoranlhene°
-luorene"
lndeno(1 ,2,3-cd)pyrenet'
2-Methylnaphthalene°
Naphthalene"
Phenanthrene"
Pyrene'
Total Benzofluoranlhenes°
Total HPAH°
Total LPAH"
2,3.7,8-TCDD (Equiv.)°
Total PCBs
Minimum
Cone, (ppb)-
NO
1,043
1.161
6,478
9.481
30.130
46.957
B.778
19,000
ND
15.222
1.913
11,870
1,710
8,696
4,222
2,593
4,783
51,304
65.957
217,348
12,304
0.00069
4,815
Maximum
Cone, (ppb)'
NO
1.680
2.080
562,963
79.355
81.935
147,200
17.645
54,839
ND
96,296
5,671
295,926
17,370
19,935
4,222
5,556
37.037
437,037
200.000
1,145,111
625,963
0.243
18,710
Mean
Cone, (ppb)
-
1,311
1.698
74.405
34.504
53,702
90.604
12,301
35.331
-
41,782
3,123
99.135
6,314
12,717
4,222
3,609
10.024
177,850
125,935
557.217
90,024
0.123
9,301
Background
Cone. (ppb)v
-
13,842
13,842
1.947
13.842
5,605
7,816
3,053
2,526
-
4,711
13,842
7.790
13.842
3,000
13,842
13,842
3.789
10,790
9.079
41,079
4,763
0.0237
6,842
Screening Toxictly
Value (ppb)
-
13.842
13,842
1.947
13,842
5.685
7.816
3.053
2,526
_
4,711
13,842
7,790
13,842
3,000
13.842
13,842
3,789
10,790
9,079
41.079
4,763
0.0237
6,842
Screening Toxiclty
Value Source
-
Background
Background
Background
Background
Background
Background
Background
Background
Background
Background
Background
Background
Background
Background
Background
Background
Background
Background
Background
Background
Background
Background
Background
HQ
Value-
-
<1
<1
269
5.73
14.4
18.6
5.78
21.7
-
20.4.
<1
38.0
1.25
6.65
<1
<1
9.77
40.5
22.0
27.9
131
10.3
2.73
COC Flag
(YorN)
N
N
N
Y
Y
Y
Y
Y
Y
N
Y
N
Y
Y
Y
N
N
Y
Y
Y
Y
Y
Y
Y
'Minimum/maximum detected concentration above the sample quantltatlon limit (SQL).
"Data normalized to lipid content.
'Based on average of detected values only.
'Hazard quotient (HQ) is defined as Maximum Concentration/Screening Toxlcity Value.
ppb: part-per-billion (ug/kg).
ND: Not detected above SQL.
Page I of 1
-------
Tahio 1Q_r>PaClfiC S°U R!sources Record o'Decision-Marine Sediments Unit
Table 19-Occurrence, Distribution and Selection of Ecological Chemicals of Concern in Fish
Exposure Medium: Fish Whole Body Tissue
Minimum/maximum detecled concentration above the sample quantitation limit (SQL)
Data normalized to lipid content.
'Based on average.
"Hazam quotient (HQ) is defined as Maximum Concentration/Screening Toxiclty Value
ppb: part-per-billion (ug/kg).
ND: Not detected of SQL.
W-UJlKlixIs I'J
Page I of I
9/28/19'W
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 20Alternate Concentration Limits
Constituents of Concern
Naphthalene
Acenaphthylene
Acenaphthene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
lndeno(1 ,2,3-cd)pyrene
Dibenzo(a,h)anthracene
Benzo(g.h,i)perylene
Dibenzofuran
Pentachlorophenol
Zinc
ACLs (pg/L)
Shallow
Wells
(9 to -6 ft MLLW)
>S
3,300
>S
930
>S
>S
>S
>S
>s
>s
>s
14
>S
0.47
>S
0.09
880
2.300
36,000
Intermediate
Wells
(-20 to -40 ft MLLW)
7,700
700
>S
200
400
900
100
>S
3.0
3.0
>S
3.0
3.0
0.1
>S
0.016
190
490
7,700
Deep
Wells
(-75 to -85 ft MLLW)
30,000
2,700
>S
790
1,000
>s
>s
>s
>s
>s
>s
12
>S
0.39
>S
0.06
750
1,900
30,000
Note:
The calculated concentrations reported in the table do not result in cleanup levels being
exceeded at the mudline. Values correspond to the shortest distance to the mudline for the
shallow, intermediate and deep zones. "S* indicates that concentrations in excess of the
individual constituent solubility level in water are required to exceed cleanup levels at the mudline.
99-0318 tbl
Page 1 of 1
28 September 1999
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 21Alternative Summary
'Disposal methods and capping volumes have been modified slightly from those provided in the FS
NA: Not Applicable '
GDZ: Groundwater Discharge Zone
CMS: Crowley Marine Services
See Figure 4 for depiction of GDZ. CMS and shoreline areas
Alternative
Alternative 1
No Action
Alternative 2
Dredging
Alternative 3a
Capping
Alternative 3b
Capping
Alternative 4a
Fill Area
Removal and
Capping
Alternative 4b
Fill Area
Removal and
Capping
1 15% hlillrinn farfnr
Cleanup
Goal
NA
CSL
SQS
CSL
SQS
CSL
Institutional
Controls
No
Yes
Yes
Yes
Yes
Yes
Monitoring
No
Yes
Yes
Yes
Yes
Yes
Cap Material
Required2
(cubic yards)
0
Offshore: 7 1.000
Shoreline: 24,000
GDZ: 20,000
Total: 115,000
Offshore: 740,000
Shoreline: 26,000
GDZ: 20,000
Total: 786,000
Offshore: 328,000
Shoreline: 23,000
GDZ: 20,000
Total: 371,000
Offshore: 531 ,000
Shoreline: 26,000
GDZ: 20,000
Total: 577,000
Offshore: 119,000
Shoreline: 23,000
GDZ: 20,000
Total: 162,000
Capping Area
(square yards)
0
Offshore: 34,000
Shoreline: 16,000
GDZ: 20,000
Total: 70,000
Offshore: 426,000
Shoreline: 18,000
GDZ: 20,000
Total: 464,000
Offshore: 193,000
Shoreline: 15,000
GDZ: 20,000
Total: 228,000
Offshore: 318,000
Shoreline: 18,000
GDZ: 20,000
Total: 356,000
Offshore: 82.000
Shoreline: 15,000
GDZ: 20,000
Total: 117,000
Dredged Volume
(cubic yards)
0
Offshore: 313,000
CMS: 9000
GDZ: 50,000
Total: 372,000
Offshore: 0
CMS: 3,500
GDZ:0
Total: 3,500
Offshore: 0
CMS: 3,500
GDZ:0
Total: 3,500
Offshore: 328,000
CMS: 3,500
GDZ: 50,000
Total: 381 ,500
Offshore: 220,000
CMS: 3,500
GDZ: 50.000
Total: 273,500
Disposal Capacity
Needed1'2
(cubic yards)
0
428,000
4,025
4,025
439,000
315,000
Disposal Facility2
NA
Nearshore, CAD
or newly
constructed
upland facility
Existing upland
facility.
Existing upland
facility.
Nearshore, CAD
or newly
constructed
upland facility
Nearshore, CAD
or newly
constructed
upland facility
'W-().M8lhl
Page 1 of 1
28 September 1999
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 22Comparison of Dredge Equipment
Dredge Type
Closed Clamshell
Cutterhead
Suction
High Energy
Vortex (Eddy
Pump)
Limited Access
Hydraulic
Depth Range
(feet) '
0-200
. 3-90
3-200
0-60
Production Rate per
24-hour day
500 - 3,500 CY
3,000-1 5,000 CY
4,000-1 8,000 CY
500-1.500CY
% Solids by
Weight
> 60%
10 to 20%
50 to 60%
10 to 20%
Resuspension
Potential
Moderate to high
Low to moderate
Low
Low to moderate
Material
Transport Method
Barge
Pipeline
Pipeline
Pipeline
Volume Increase
at Disposal Point
15-25%
15-25%
15-25%
15-25%
CY = Cubic Yards
W-0318 ihl
Page lof 1
^t 1
28 September 19'
999
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 23Estimated Schedule of Available Capping Material
Source Location
Duwamish River:
Upstream of
Settling Basin
Duwamish River:
Lower Reach
Snohomish River:
Upper Reach
Snohomish River:
Lower Reach
Everett Home
Port
Percent
Sand
70-90%
<50%
90%
70%
70%
(est.)
Annual Volume of Sandy
Material (excludes lower
Duwamish River)
Annual Total Volume
Cumulative Volume of Sandy
Material (excludes lower
Duwamish River
Cumulative Total Volume
1999
40,000 CY
1 00,000 CY
0
0
0
40,000 CY
140,000 CY
40,000 CY
140,000 CY
2000
0
0
0
0
1 50,000 CY
1 50,000 CY
1 50,000 CY
1 90,000 CY
290,000 CY
2001
40,000 CY
1 00,000 CY
0
240,000 CY
0
280,000 CY
380,000 CY
470,000 CY
670,000 CY
2002
0
0
240,000 CY
0
0
240,000 CY
240,000 CY
71 0,000 CY
91 0,000 CY
2003
40,000 CY
1 00,000 CY
0
240,000 CY
o
280,000 CY
380,000 CY
890,000 CY
1 ,290.000 CY
2004
0
0
0
0
o
0
0
890,000 CY
1, 290,000 CY
I d
2005
40,000 CY
100.000CY
240,000 CY
240,000 CY
320,000 CY
420,000 CY
1,210,000 CY
1,710,000 CY
CY = Cubic Yard.
Dredge Material from Upper Snohomish River may not be available until 2002 due to existing commitments
Available quantities are variable depending on runoff and dredging requirements.
99-03l8.lbl
Page 1 of 1
28 September 1999
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 24Items To Be ConsideredPSR Site Sediment Remediation
Federal, State, and Local Criteria, Advisories and Procedures
Guidelines developed by the Elliott Bay/Duwamish
Restoration Panel
Puget Sound Water Quality Management Plan
Standards for Confined Disposal of Contaminated Sediments,
Washington Department of Ecology (January 1990)
Federal and State Water Quality Guidance Documents
Area of Contamination Interprogram Policy, developed by
Washington Department of Ecology
Sediment Cleanup Standards Users Manual, Washington
State Department of Ecology (December, 1991)
Sediment Source Control Standards Users Manual,
Washington State Department of Ecology (June, 1993)
Local Shoreline Master Program
Sediment Quality Criteria for the Protection of Human Health
Comments
Guidelines for habitat restoration
Defines objectives for standards
regarding the confined disposal of
contaminated sediment
Guidelines for assessing the suitability of
dredged material for unconfined disposal
relevant to cap material specifications
Contains policy and technical data
reviewed and/or used in the development
of state sediment management
standards
Guidelines for the management of
dredged sediment meeting the criteria as
a state dangerous waste
Guidance for implementing the sediment
cleanup decision process for
contaminated sediments in Washington
State
Guidance for implementing the Sediment
Source Control Standards
Guidelines for managed development of
shorelines to preserve natural resources
while protecting public access and
navigation.
Proposes draft sediment quality
standards based on risks to humans
99-0318 tbl
Page 1 of 1
29 September 1999
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 25Revised Costs Summary for MSU Remedial Alternatives
Alternative
2-Dredge to CSLs
3a-Cap to SQS
3b-Cap to CSLs
4a-Dredge/Cap to SQS
4b-Dredge/Cap to CSL
Cost
$6,010,000
$6,010,000
$12,520,000
$6,440,000
$12,430,000
$12,430,000
$12,430,000
$5,500,000
$5,500,000
$5,500,000
Disposal Method
Nearshore
CAD
Constructed Upland
Established Upland
Established Upland
Nearshore
CAD
Constructed Upland
Nearshore
CAD
Constructed Upland
Disposal
Cost*
$11,128,000
$7,704,000
$19,260,000
$619,000
$619,000
$11,414,000
$7,902,000
$19,755,000
$8,190.000
$5,670,000
$14,175,000
Mitigation
Cost"
$5,250.000
_
_
$5,250,000
$4.350,000
_.
Revised Cost
$22,388,000
$13,714,000
$25,270,000
$13,139.000
$7,059,000
$29,094,000
$20,332,000
$32,185,000
$18,040.000
$11,170,000
CAD and Nearshore costs from FS. Established upland facility costs have been revised.
" Mitigation costs from PSR Responsiveness Summary. Does not include cost of DNR land use.
99-0318c.xls 25
Page 1 of 1
9/29/1999
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 26Cost Estimate Summary of Alternative 2 - Dredging to CSLs
Year
0
1
2
3
4
5
6
7
e
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Capital Cost
4,806.000
O&M Cost
Cap
Mahiananoa
42,600
42.600
42,600
42,600
42.600
42.600
42.600
42,600
42,600
42.600
42.600
42.600
42,600
42.600
42.600
42.600
42.600
42.600
42.600
42.600
42.600
42.600
42.600
42.600
42.600
42.600
42.600
42.600
42.600
42.600
dp
Monitoring
-
56,700
.
56,700
.
56,700
-
56,700
-
56.700
-
56.700
-
56.700
.
56,700
-
56.700
.
56.700
-
56,700
-
56.700
.
56.700
-
56,700
-
56.700
Dredge Area
Monitoring
44,550
44,550
44,550
44,550
44,550
44.550
Discount Factor
5%
0.952
0.907
0.864
0.823
0.784
0.746
0.711
0.677
0.645
0.614
0.585
0.557
0.530
0.505
0.481
0.458
0.436
0.416
0.396
0.377
0.359
0.342
0.326
0.310
0.295
0.281
0.268
0.255
0.243
0.231
Present Worth
Cap
Maintenance
40.571
38.639
36,799
35,047
33.378
31.789
30.275
28.833
27,460
26.153
24.907
23.721
22.592
21,516
20.491
19.516
18.586
17,701
16.858
16.055
15,291
14,563
13.869
13.209
12.580
11.981
11,410
10,867
10,350
9,857
Cap
Monitoring
51,429
-
46.647
-
42,310
-
38.377
34.809
-
31,573
-
28,637
-
25,975
-
23.560
-
21,370
-
19,383
-
17,581
-
15.946
-
14,464
-
13,119
Dredge Ana
Monitoring
-
-
-
-
34,906
-
-
-
-
27,350
-
-
-
-
21,429
-
-
-
-
16,790
-
-
-
-
13,156
-
-
-
-
10.308
Total Present
Worth
4.806.000
40.571
90,068
36,799
81.694
68,284
74.099
30.275
67,210
27.460
88.311
24,907
55.294
22.592
50,153
41.921
45,490
18,586
41.261
16.858
54.216
15.291
33.946
13,869
30,790
25,736
27,927
11,410
25.331
10.350
33.284
Total Present Worth Cost 6,010,000
»9-0)IX<:xll26
Page 1 of 1
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 27Cost Estimate Summary of Alternative 3a - Capping to SQS
Year
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Capital Cost
9,613,000
O&M Cost
Cap Maintenance
87,000
87,000
87,000
87,000
87.000
87,000
87,000
87,000
87,000
87.000
87.000
87,000
87,000
87,000
87,000
87.000
87,000
87,000
87,000
87,000
87,000
87,000
87,000
87,000
87,000
87,000
87,000
87.000
87.000
87,000
Cap Monitoring
-
208,800
.
208,800
-
208,800
-
208,800
-
208,800
-
208,800
-
208,800
-
208,800
r
208,800
-
208,800
-
208,800
-
208,800
-
208,800
.
208,800
-
208.800
Discount Factor
5%
0.952
; 0.907
0.864
0.823
0.784
0.746
0.711
0.677
0.645
0.614
0.585
0.557
0.530
0.505
0.481
0.458
0.436
0.416
0.396
0.377
0.359
0.342
0.326
0.310
0.295
0.281
0.268
0.255
0.243
0.231
Present Worth
Cap Maintenance
82,857
78.912
75,154
' 71,575
68,167
64,921
61,829
58,885
56,081
53,410
50.867
48,445
46,138
43,941
41,848
39,856
37,958
36,150
34,429
32.789
31.228
29.741
28,325
26,976
25,691
24,468
23.303
22,193
21.136
20,130
Monitoring
-
189,388
171,780
'
155,810
-
141.324
.
128,185
-
116,268
-
105.458
95.654
-
86.761
-
78,695
-
71,378
"
64,742
-
58,723
-
53,264
-
48,312
Total Present
Worth
9,613,000
82,857
268,299
75,154
243,355
68,167
220,731
61,829
200.209
56.081
181,596
50,867
164,713
46,138
149.399
41,848
135,509
37,958
122,91 1
34,429
111,484
31,228
101,119
28,325
91,718
25,691
83,191
23,303
75,457
21.136
68.441
Total Present Worth Cost 1 2.520,000
99-03l8c.xls 27
Page I of I
9,79,1999
-------
Paciflc Sound Resources Record of DecisionMarine Sediments Unit
Table 28Modified Alternative 3b - Capping to CSLs
Capital Cost
Unit | Quantity j
Crowley Marine Terminal Dredging
Dredge Mobilization
Dredging w/Clamshell
Short Term Monitoring
3. Groundwater Discharge Area Ca
Transport and Placement
B. Short-term Monitoring - Capping
Water Quality Monitorin
3,720.00
11.700.00
Bathymetric/Sed. Profile Surveys
. Shoreline Area Capping
Transport and Placement
3. Short-term Monitoring - Capping
Water Quality Monitorin
Bathymetric/Sed. Profile Surveys
. Non-shoreline Area Capping
Transport and Placement
B. Short-term Monitoring - C
Water Quality Monitorin
$61.258
$11,700
Bathymetric/Sed. Profile Surv
Subtotal Capital Costs
$3,288.146
$328.815
dministrative Cost
% SUBTOTAL
Engineering Expenses
% SUBTOTAL
'ontingency Allowances
Total Capital Costs
99-0318c xls 28
Page 1 of 1
9/29/1999
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 29Cost Estimate Summary of Alternative 3b - Capping to CSLs
Year
0
1
2
3
4
5
6
7
8
9
10
1.1
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Capital Cost
4,930,000
O&M Cost
Cap Maintenance
41,985
41,985
41.985
41.985
41,985
41,985
41,985
41.985
41.985
41,985
41,985
41,985
41,985
41,985
41,985
41 ,985
41,985
41,985
41.985
41.985
41,985
41.985
41,985
41 .985
41,985
41.985
41.985
41,985
41,985
41,985
Monitoring
-
114.600
-
114.600
-
114,600
.
114.600
-
114,600
.
114,600
.
114,600
-
114,600
- -
114,600
-
114.600
-
114.600
-
114,600
-
114.600
-
114,600
-
114,600
Discount Factor
5%
0.952
0.907
0.864
0.823
0.784
0.746
0.711
. 0.677
0.645
0.614
0.585
0.557
0.530
0.505
0.481
0.458
0.436
0.416
0.396
0.377
0.359
0.342
0.326
0.310
0.295
0.281
0.268
0.255
0.243
0.231
Present Worth
Cap Maintenance
39,986
38,082
36,268
34,541
32,896
31,330
29,838
28.417
27,064
25,775
24,548
23,379
22,266
21.205
20,196
19,234
18,318
17,446
16,615
15,824
15,070
14,353
13,669
13,018
12.398
11.808
11.246
10,710
10,200
9,714
Monitoring
-
103,946
-
94,282
-
85,516
-
77,566
-
70.354
.
63,814
-
57,881
-
52,500
-
47,619
-
43.192
-
39.176
-
35.534
-
32,230
-
29.234
-
26.516
Total Present
Worth
4,930,000
39,986
142.027
36,268
128.823
32.896
116,846
29,838
105,983
27.064
96,130
24,548
87.192
22,266
79,086
20,196
71,733
18,318
65,064
16,615
59.015
15,070
53,529
13,669
48,552
12,398
44,038
11,246
39,944
10,200
36,230
Total Present Worth Cost 6,440.000
99-03l8c«Js29
Page I of t
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 30Cost Estimate Summary of Alternative 4a - Fill Removal to SQS and Cap
Year
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Capital Cost
10.024.000
O&M Cost
C«P
Maintenance
64.600
64.600
64.600
64.600
64.600
64.600
64.600
64.600
64.600
64.600
64.600
64.600
64.600
64.600
64,600
64.600
64.600
64,600
64.600
.64.600
64.600
64.600
64.600
64.600
64.600
64.600
64,600
64,600
64.600
64.600
Cap
Monitoring
-
174.000
-
174.000
-
174,000
-
174,000
-
174,000
-
174.000
-
174.000
-
174.000
-
174.000
174.000
-
174.000
-
174,000
-
174.000
-
174,000.
-
174,000
Dredge Ana
Monitoring
38,000
38,000
38,000
38.000
38,000
38.000
Discount Factor
5%
0.952
0.907
0.864
0.823
0.784
0.746
0.711
0.677
0.645
0.614
0.585
0.557
0.530
0.505
0.481
0.458
0.436
0.416
0.396
0.377
0.359
0.342
0.326
0.310
0.295
0.281
0.268
0.255
0.243
0.231
Present Worth
Cap
Maintenance
61,524
58.594
55.804
53.147
50.616
48.206
45,910
43,724
41.642
39,659
37,770
35,972
34,259
32,627
31.074
29.594
28.185
26.843
25,564
24,347
23.188
22.084
21,032
20,030
19.077
18.168
17.303
16,479
15.694
14,947
Cap
Monitoring
-
157,823
-
143,150
-
129,841
-
117,770
-
106,821
-
96.890
-
87,882
-
79,711
-
72,301
,
65,579
.
59.482
-
53.952
-
48,936
-
44,386
-
40.260
Dredge Area
Monitoring
.
-
-
.
29,774
-
-
.
.
23.329
-
-
-
-
18,279
-
. .
.
.
14.322
.
.
.
.
11,222
-
.
.
-
8.792
Total Present
Worth
10,024,000
61,524
216,417
55.804
196,297
80.390
178.047
45.910
161.494
41.642
169.808
37.770
132,861
34.259
120.509
49,352
109,305
28,185
99.143
25.564
104.248
23.188
81,565
21,032
73.982
30.298
67,104
17,303
60,865
15,694
63,999
Total Present Worth Cost 12.430,000
Page 1 of I
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Table 31Cost Estimate Summary of Alternative 4b - Fill Removal to CSLs and Cap
Year
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Capital Cost
4,585.000
Cap
Maintenance
19,300
19,300
19,300
19.300
19,300
19,300
19,300
19,300
19,300
19,300
19,300
19,300
19.300
19,300
19,300
19,300
19,300
19,300
19,300
19,300
19,300
19.300
19,300
19,300
19.300
19,300
19,300
19,300
19.300
19,300
Cap
Monitoring
-
67.500
67.500
-
67.500
-
67,500
-
67,500
-
67,500
- '
67,500
-
67.500
-
67,500
-
67,500
-
67.500
-
67.500
-
67,500
-
67,500
-
67.500
Dredge Area
Monitoring
39.100
39,100
39,100
39.100
39.100
39,100
Discount Factor
S*
0.952
0.907
0.864
0.823
0.784
0.746
0.711
0.677
0.645
0.614
0.585
0.557
0.530
0.505
0.481
0.458
0.436
0.416
0.396
0.377
0.359
0.342
0.326
0.310
0.295
0.281
0.268
0.255
0.243
0.231
Present Worth
Cap
Maintenance
18.381
17.506
16,672
15,878
15,122
14,402
13,716
13,063
12.441
11.849
11,284
10,747
10,235
9.748
9.284
8.842
8.421
8.020
7.638
7.274
6.928
6.598
6.284
5.984
5.699
5.428
5,169
4,923
4.689
4.466
Cap
Monitoring
-
61.224
.
55.532
-
50.370
.
45,687
-
41,439
.
37,587
-
34.092
-
30,923
.
28,048
-
25,440
-
23,075
.
20,930
-
18,984
-
17,219
-
15.618
Dredge Area
Monitoring
.
_
.
30.636
.
.
.
-
24,004
.
.
_
.
18.808
.
.
.
.
14,736
-
-
-
.
11.546
.
.
_
9.047
Total Present
Worth
4,585,000
18.381
78.730
16,672
71.411
45,758
64,771
13.716
58,750
12.441
77.292
11,284
48,333
10.235
43.840
28,091
39,764
8.421
36.067
7,638
47,450
6,928
29.673
6.284
26,914
17,246
24.412
5.169
22,142
4,689
29.130
Total Present Worth Cost 5 500 000
Page i of I
-------
Table 32: Cost Estimation for Groundwater Monitoring and DNAPL Collection
(Pacific Sound Resources: Record of Decsion)
h*m - Description
Capital Cojts
Recovery Well Upgrades new monuments for 7 wells (installed
Monitoring Well Construction MW-16S; 2"- SS cuing with sump
MW-16I; 2"-SS caring with sump
MW- 1 12: 2"-SS casing with sump
Equipment Shed Metal shed on concerte slab w/ garage
doors, heating, ventilation, lighting
Service Vehicle 3/4-ton pick-up with end lift
Miscellaneous Equipment pumps, secondary containment, tools
health and safety, decontamination, e
Subtotal Capita] Cost
Engineering design, overhead and administration
Deed restrictions attorney's fees
Total Capital Cost
Atuuul Operation tnd Mainteiuuut Cat
Groundwater Monitoring - Analytical Costs (12-welt network -i- 20% for QA/QC)
Annual costs years 1-5 (quarterly) subcontract laboratory
Annual costs years 6-10 (scmiannually) subcontract laboratory
Annual costs years 1 1-30 (annually) subcontract laboratory
Groundwater Monitoring - Labor Costs
Annual costs years 1-5 (quarterly) sampling and reporting
Annual costs yean 6-10 (semiannually) sampling and reporting
Annual costs years 1 1-30 (annually) sampling and reporting
Expendible Materials and Fuel PPE, sampling, decontamination
Well. Equipment and Facility Maintenance
DNAPL-to-Energy Recovery Facility manifesting, shipping and disposal
PPE and Miscellaneous Waste Disposal manifesting, shipping and disposal
Present Worth of O&M Cost 8% discount rate
General Project Administration and Overhead (5% of subtotal)
Contingency (10% of subtotal)
'otal Present Worth Cost
Quantity
7
22
54
54
500
1
1
tc.
1
1
58
29
15
Units
each
foot
foot
foot
square foot
lump sum
lump sum
lump sum
lump sum
each
each
each
lump sum
lump sum
lump sum
lump sum
lump sum
tump sum
lump sum
Unit
Cost(S)
1. 000
too
100
100
40
15.000
10.000
50000
5.000
300 '
300 '
300 '
24.000 i
12.000 '
6.000 l
1.500
5.000
4,000
2,000
Total
Cost
$7.000
$2.200
$5.400
S5.400
$20.000
$15.000
$10.000
$65.000
$5flioOO
$5.000
$115,000
$17.400
$8.700
$4,500
$24.000
$12.000
$6.000
SI. 500
$5.000
$4,000
$2.000
$370.000
$18.500
$37.000
$541,000
NOTES:
1 Unit costs for PAH and diberizoruran by EPA Method 8310 is $200.
Unit costs for PCP by EPA Method 8040 is $ 100.
1 Labor costs for a single sampling round are as follows:
Held Technician
Chemist (data QA/QC)
Staff Hydrogeologist
CAD Operator
Supervisor
24
8
60
6
S
hours
hours
hours
hours
hours
45
58
58
45
88
$1.080
$464
$3.480
S270
S704
Total
$6.000
-------
PACIFIC SOUND RESOURCES (PSR)
SUPERFUND SITE
SEATTLE, WASHINGTON
RECORD OF DECISION:
PART 3: RESPONSIVENESS SUMMARY
September 1999
-------
-------
Pacific Sound Resources Record of Decision: Responsiveness Summary September 1999
TABLE OF CONTENTS
Section - page
1. POTENTIAL IMPACTS TO TREATY RIGHTS 1
2. POTENTIAL IMPACTS TO LAND USE 3
3. RISK .....r...3
4. ARARs 4
5. CLEANUP LEVEL SELECTION . 5
6. DESIGN ISSUES ... 6
6.1 Capping at Depth 6
6.2 Geotechnical 9
6.3 Cap Thickness....... 11
6.4 Cap Source Material 13
6.5 Cap Placement 14
6.6 Life/Duration 15
6.7 General Issues......................................... ......... 15
7. COST EFFECTIVENESS 16
8. SOURCE CONTROL AND POTENTIAL FOR RECONTAMINATION 16
9. NATURAL RECOVERY 17
10. RAOs/EVALUATION CRITERIA 17
11. MONITORING 19
12. DISPOSAL/SITING 20
13. RESTORATION GOALS 20
14. EDITORIAL COMMENTS 21
-------
1
Pacific Sound R^^ Record of Decision: Responsiveness Summan, _ _ Berber ,999
TABLE OF CONTENTS (CONTINUED)
°N THE «* MARINE SEDIMENTS UNIT
PSR UPLAND GROUNDWATER RI/FS
ATTACHMENT 1-REVISED RISK CALCULATIONS
DATA FROM THREE BORINGS
PUMP DEMONSTRATION PERFORMANCE DATA
LIST OF TABLES
I Sediment Cap Input Data
2 Modified Costs Incorporating Revised Assumptions for Long-term Monitoring
LIST OF FIGURES
1 PSR Marine Sediments Unit NO AA Total PAH
IV
-------
\
PACIFIC SOUND RESOURCES (PSR)
SUPERFUND SITE
SEATTLE, WASHINGTON
RECORD OF DECISION:
RESPONSIVENESS SUMMARY
This is the Responsiveness Summary for comments received regarding the draft Upland
Groundwater Remedial Investigation/Feasibility Study, the draft Marine Sediments Unit
Feasibility Study and the Proposed Plan for cleanup of the Pacific Sound Resources Superfund
site. The first two sections of this Responsiveness Summary address the comments received
regarding the draft Marine Sediments Unit Feasibility Study and the Proposed Plan. Several
reviewers provided similar comments on these documents; responses and discussions are
organized by general topic and EPA's responses are presented in the first section of this
Responsiveness Summary. The second section includes a copy of all original comments
received on the Marine Sediments Unit Feasibility Study and Proposed Plan and responds to
issues that were not addressed in the first section. The third section of this Responsiveness
Summary presents the comments received, and EPA's responses to the draft Upland
Groundwater RI/FS.
1. POTENTIALIMPACTS TO TREATY RIGHTS
The primary concern raised by the tribes focused on the impact of the selected remedy relative to
treaty-protected rights of net fishing and shellfish gathering in Elliott Bay. More specifically,
reviewers were concerned that disposal options or institutional controls may preclude these
activities. In addition, the tribes have requested that any aspect of a cleanup that would impact
tribal activities should be coordinated with the Tribes.
EPA has modified the Proposed Plan such that treaty rights will not be impacted. The cleanup
alternative selected by EPA for the PSR Marine Sediments Unit is a modification of Alternative
3b that was presented in the Feasibility Study Report (WESTON1998). This remedy relies
primarily upon capping (a small area will be dredged near Crowley Marine to maintain
navigational depths) to confine contaminated sediments. The alternative was modified to include
additional capping in the nearshore and intertidal environments to protect human health and
natural resources that may be impacted by contaminants (specifically PCBs) that were released
from the old Seattle Landfill and were discharged to Elliott Bay via Longfellow Creek overflow.
Currently, small pocket beaches exist on either side of the peninsula that now contains the public
viewing tower; these beaches are connected by a strip of beach that formed at the toe of the
riprap bank. The total area is about 2 acres and is exposed during daylight hours between 0 (the
approximate toe of the constructed bank) and -4 MLLWfor approximately 72 days per year for
an average of 2.6 hours a day (assuming at least an hour would be required to harvest shellfish).
-------
Pacific Sound Resources Record of Decision: Responsiveness Summary September 1999
°CCeSSible *y ld*« ^fencing
Restrictions on shellfish gathering (i.e., institutional controls) were proposed for the minimal
internal area that is available in order to maximize ^^ttJ^^therem^fyA- IfL
capias proposed in the internal areas and it was assumed that institutional controls would be
necessary because a cap this thick could potentially be penetrated while digging for shellfish In
response to Tribal concerns, EPA will place a thicker cap (5-foot deep) ^alongt^Ki^
and internal areas that will allow far unrestricted harvesting ofshetyish fc £ fsitu'onal
controls regarding shellfish gathering will be included in the ROD). institutional
capping approach was reviewed to determine how the thicker cap would
Qdditi0nal CQP material' * * determined the
r u '
thicker p wuld need to be expanded out to a depth of approximately -8.0 MLLW (100 to
150 feet offshore) in the shoreline southeast of the piers. The remaining shoreline could
SST A r additi°nfal Capplns material within the exiting footprint of the shoreline cap The
thicker shoreline cap footprint is shown in Figure 4 of the Record of Decision.
Placement of additional cap material to support shellfishing in the intertidal areas of the site is
estimated to require an additional 8,000 cubic yards of cap material. This
to about -10 feet MLLW) represents a potentially higher energy environment. During desisn the
Situated Sneered features to maintain a thicker cap in the shoreline will be
^ iS f ° Pr°POSed "* Part °fthis remedy- This titutional control
anrhn Th "^ *° ** Capfrom comtner^ ^els using large whale-tail type
would no^da T" l ^ affe? netfisherS ln that Sma" b°at anch and < ^Ls
would not damage the cap A no-anchor zone must be implemented by a Rule-making through
£ , 7* * ^ Army CorpS °fEnSi^ers, in consultation with the Department of
Natural Resources. The Rule-making would be subject to public review. ePanm( <>J
* "°te, th0t, EPA HaS consistently coordinated with the Muckleshoot and
throughout the cleanup process at the PSR site and will continue to do so
Specifically, comments were solicited from the tribes as part of the technical review of the
^hn^, mv,esp^ation scoping memorandum and work plan, the sampling and analysis plan
draft rimed' I < '" ***"* "* ^^ *""* ^ «ofo«fcfl/ ^ assessment, "the '
^ftreme dial invesU ga tion report, the feasibility study technical memoranda, and the draft FS
report Several stakeholder meetings were held to receive input and inform Trustees and
regulators of the status of the project during the RI scoping phase, at the conclusion of the RI
field sampling phases, and during the development of the alternatives to be evaluated in the FS.
-------
Pacific Sound Resources Record of Decision: Responsiveness Summary September 1999
2. POTENTIAL IMPACTS TO LAND USE
Because capping is the remedy proposed for the site, a number of reviewers expressed a concern
that capping would impact future use within the Harbor Area, particularly if deepening in the
nearshore would be a component of future use; A second concern was that the associated no-
anchor zone over the cap would limit navigation and other marine activities such as laying cable
in and around the Harbor Area.
The selected remedy (modified Alternative 3b)for the site relies upon a cap to confine
contaminated sediments. A small area will be dredged near Crowley Marine prior to capping to
maintain current navigational depths. The Port of Seattle does not have a need for deep-draft
capabilities in this area of the harbor, at this time (Doug Hotchkiss, pers. comm.). Other
development plans for areas adjacent to the site may also affect future development as a deep
draft facility. Ecology has proposed construction of a nearshore CAD facility as part of the
remediation of the adjacent Lockheed Shipyard. The eastern portion of the PSR MSU has also
been considered as an expansion site if the Lockheed nearshore CAD were to be developed as a
Multi-User Disposal Site. If the use of the PSR MSU should change in the future, additional
dredging could be performed but would require disposal or treatment of contaminated sediments
that would be removed.
A no-anchor zone over the cap is also proposed as part of this remedy. The no-anchor zone
would be approximately 47 acres in size and would represent about 2 percent of the total
anchorage area available in Elliott Bay (approximately 2,000 acres are designated for
anchorage within Elliott Bay). This institutional control was included to prevent damage to the
cap from commercial vessels using large whale-tail type anchors. Currently, this area is used
only for barge moorage affixed anchor buoys. This type of moorage is not expected to be
restricted. Other marine activities, such as cable laying, would have to be evaluated on a case-
by-case basis. Large marine cable is typically buried a meter below the mudline (or has the
capacity to self-bury to that depth); smaller cables cause less disturbance of the bottom.
Accidental damage to the cap would be assessed as part of the long-term operations and
maintenance plan for the remedy.
3. RISK
Multiple issues were raised by reviewers regarding the assessment of risk associated with the
remedy. Many reviewers felt that the proposed remedy did not fall within the MTCA risk range
and would not be as protective as a cleanup under the State's process. Reviewers took specific
exception to the use of the Sediment Management Standards for evaluating bioaccumulative
contaminants, interpretation of the risk calculations, and development and use of background
contaminant levels.
EPA believes that the risks remaining following cleanup will be protective of human health and
ecological receptors. Ecological risks were evaluated for bioaccumulative contaminants as part
of the original risk assessment. The risk evaluation indicated that protecting human health
-------
1
Pacific Sound Resources Record of Decision: Responsiveness Summary September 1999
would also protect ecological receptors because (for the endpoints evaluated) the human health
response was more sensitive to the contaminants associated with this site; therefore, all risk
evaluations during the FS were based on human health. As part of the modifications to
Alternative 3b, EPA re-evaluated the residual risks to human receptors under a post-cleanup
scenario. As part of this re-evaluation, post-cleanup risks were recalculated by assuming that
all nearshore areas (less than -10ft MLLW) were capped along with all other areas with PAHs
greater than the CSL. The resulting post-cleanup risks to human health fall within the range of 1
in 100,000 (1E-5). Residual risks for consumption offish and mobile shellfish (i e shrimp and
crab) from the site over a lifetime for the RME receptor was 4.2E-5. The uncertainties in any
risk assessment affect the estimations of risk such that the estimates are only accurate to within
an order of magnitude; thus 4.2E-05 represents a risk of the same order of magnitude as IE-OS
Revised risk calculations are provided in Attachment 1.
The proposed remedy for the Marine Sediments Unit relies upon capping to confine the
contaminated sediments and prevent exposure of human and ecological receptors. Although the
area to be capped is primarily defined by the SMS CSL, the resulting sediment quality within the
capped area will be at least as clean as the SQS (a requirement for selection of capping
material). In calculating the risks remaining following cleanup, average background
concentrations from Elliott Bay were used to estimate sediment quality in areas to be capped
(i.e., background values were substituted for those samples representing the area to be capped).
Use of background concentrations to estimate surface sediment concentrations on the cap was '
considered reasonable because sediments would tend to equilibrate with the existing conditions
over time. Average background concentrations (based on RI samples) fall below the SMS
sediment quality standards and fall within the MTCA risk range oflE-05. Because Elliott Bay
background samples tended to have chemical concentrations less than the SQS, risks are lower
under a capping scenario compared to dredging to the standard.
4. ARARs
Several reviewers felt that the alternatives evaluated in the FS did not meet risk ARARs;
specifically, it was thought that several alternatives (including the proposed remedy) did not
comply with MTCA risk ranges.
The Model Toxics Control Act does not address acceptable risk ranges associated with cleanup
of sediments; MTCA references the Sediment Management Standards. The SMS do not have a
numeric risk goal for the protection of human health. MTCA is not an ARARfor sediment
cleanups. Nevertheless, the alternative proposed for implementation at the site (cap with limited
dredging to maintain navigational depths) will result in a risk equivalent to 1 in 100,000 and
thus would meet MTCA risk goals.
The Corps suggested that additional ARARs be considered; the Washington Hydraulic Code,
Tribal Government to Government Presidential Memorandum, and the National Historic
Preservation Act.
-------
Pacific Sound Resources Record of Decision: Responsiveness Summary September 1999
The Washington Hydraulic Code is included as an ARARfor the site. The cited Presidential
Memorandum does not include specific substantive environmental or facility siting requirements
and as such is not an ARAR. The Port of Seattle addressed the National Historic Preservation
Act as part of the Southwest Harbor Project EIS. Therefore, no modifications will be made to
the evaluation ofARARs, based on these comments.
5. CLEANUP LEVEL SELECTION
Several reviewers are concerned that selection of the CSLs as the cleanup level for PAHs is not
protective of human or ecological health.
As part of the initial risk assessment, preliminary remediation goals were calculated separately
for human and several ecological receptors. Human cancer risk was shown to be the most
sensitive endpoint and was used as a surrogate for all other receptors. Human health effects
were used to identify the areas of highest risk at the site, which were coincident with the CSL
boundary. As discussed in Section 3 of these responses, the resulting sediment quality following
cleanup of the area defined by CSL exceedances will be protective of human health in that risks
fall within the range ofl in 100,000. The CSL boundary also encompasses the area identified by
the subbottom profiling and subsurface sampling data as potential fill north of the upland facility
and a secondary discharge/disposal area north of Crowley Marine Services (i.e., this is the area
where there are significant accumulations of contamination up to 96 percent of the total
contaminant mass).
Under the Sediment Management Standards, the cleanup of a site should result in an elimination
of adverse effects on biological resources and significant health threats to humans. The SQSare
considered the numerical values that correspond to the narrative goal. A site-specific cleanup
standard is to be as close as practicable to the SQS, given consideration of environmental
effects, feasibility and cost. Given site-specific factors, the minimum cleanup standard (MCUL)
for PAHs has been selected as the trigger for active remediation of sediments within the PSR
MSU because this level represents the minor adverse effects threshold for benthic organisms. In
addition, capping in the CSL exceedance area results in a significant reduction in risks to human
health such that the NCP requirements regarding risks are met (the MTCA risk ranges that apply
to soil and groundwater would also be met). An exception to the use of the minimum cleanup
level (MCUL; equivalent to the CSL) is in the cleanup ofPCBs in the nearshore environment. At
those locations, PCB sediment concentrations exceeding the Sediment Quality Standard (SQS)
will be included in the area to be remediated.
The justification for selection of the MCUL for PAHs is as follows:
the MCUL is protective of benthic communities at this site. No benthic failures occurred at
the biological sampling stations within the MCUL boundary. Bioassay failures were noted,
but were generally in the minor adverse effects range. Given that minor adverse impacts
occurred in samples collected from the MCUL/CSL exceedance area where more severe
effects were anticipated, based on chemical concentrations, only minor to minimal adverse
impacts would be predicted in remaining areas with sediment concentrations between the
SQS and the MCUL/CSL.
-------
Pacific Sound Resources Record of Decision: Responsiveness Summary
IQQQ
human health risks fall with the risk range required by the NCP (and would also meet
MTCA ranges).
cleanup costs to achieve the SQS across the entire site were greater than 190 percent of the
costs to achieve CSL (greater than II 0 percent is considered significant under the SMS
guidance)
cleanup to the MCUL/CSL addresses the areas of contaminated sediment accumulation
which contains the greatest mass of contaminants
the majority of the sediments that exceed the SQS and will remain following cleanup are in
deep (>100ft) water, and provide minimal exposure potential to fishers and recreational
users of the bay. Achieving cap performance goals in deeper areas is less certain and
would require significant additional capping material, possibly greater engineering of the
cap, and longer duration of the cleanup.
Justification for selection of the SQSforPCBs in the nearshore environment is:
the nearshore environment provides critical habitat for juvenile salmonids and their prey.
the MCULfor PCBs does not provide the same degree of protection as other chemicals
because it does not address bioaccumulative effects (invertebrates are relatively insensitive
to bioaccumulative chemicals because they are short-lived and lack some of the key
enzyme systems that contribute to the production of cancer).
ensures that the Trustees restoration goal for PAHs is met in the shallow, nearshore
critical habitat area.
Confinement through capping provides additional protection of resources (including fish) in that
capping material must meet the SQS. Thus 47 acres of the site will be at or below the SQS and
the remaining area will be between the SQS and the CSL. It is likely that there will be additional
benefit from capping in the SQS exceedance areas as cap material is lost during placement in
deeper water or material migrates from the CSL boundary areas (see Sections 9 and 13 of these
responses for further discussion).
6. DESIGN ISSUES
Reviewers raised a number of issues relative to the design of the remedy. Design issues and
discussions are presented by subtopic below.
6.1 Capping at Depth
had conflicting comments regarding the feasibility of placing a cap at depths greater
than 200 feet and ensuring the performance criterion of obtaining a minimum 3-foot thickness
The Corps felt that capping at depth was feasible based on a recent demonstration capping
project at the PSDDA site in Elliott Bay. Ecology felt that the issue still needed further
investigation during the design phase.
-------
Pacific Sound Resources Record of Decision: Responsiveness Summary - September 1999
Achieving Cap Thickness Performance CriterionAchieving the required thickness of the
placed material could be accomplished in a manner similar to that used at Eagle Harbor.
Monitoring the volume of material being placed and accurately recording the placement
locations would allow the average cap thickness to be indirectly calculated as the project
proceeded. However, precisely controlling the placement of material in water depths of 30 feet
to 200 feet probably isn 't warranted. Controlling the placement of material in a marine
environment presents additional challenges, not generally encountered in placing a layer of
asphalt on a road or covering a landfill. There is no method to "grade " the finished surface to
the tolerances usually associated with terrestrial construction (0.1 ft), nor is there any way to
directly inspect the completed project to assure that the design tolerances have been met. The
inability to "see or feel" the capping site directly introduces an-additional uncertainty into the
design. Adjusting construction methods and tolerances to meet the design objectives in the most
economical manner possible is often the best way to accommodate this uncertainty. A large
tolerance in cap thickness would allow the use of readily available construction equipment, and
uncomplicated placement methods. For this reason, a relatively simple placement design that
requires a large volume of capping material may be less costly than a complicated design that
requires the precise placement of a minimum volume of capping material.
Significant variations in the cap thickness should be anticipated in the design of the project. A
design thickness of 5 feet to 6 feet maybe required to assure that a minimum cap thickness of
3 feet has been achieved. A 15 percent contingency for loss during placement may be
appropriate for estimating capping material with a very low percent of fines, but sufficient
quantities of this type of dredged material may not be readily available. Estimating capping
material needs based on loss of 25 percent or higher would allow for the placement of dredged
material from a wider range of sources. Assuming an average cap thickness of 5 feet and loss of
25 percent at all water depths results in a capping volume of about 500,000 cubic yards (cy).
This estimate assumes 25 percent of the capping material is fine-grained (clay and silt) that
settles so slowly that it will be carried off site regardless of the water depth. This estimate differs
from that presented in the FS (363,000 cy), because the estimate in the FS assumed only material
sufficient for a 3-foot cap with a potential loss of 15 percent would occur when capping in water
depths less than 60 feet. Assumptions when estimating the volume required for capping at
greater than 60 feet were the same as presented here. The target cap thickness of 5 feet is a
conservative "first cut" and represents an average thickness that should assure a minimum
thickness of 3 feet has been achieved throughout the cleanup area. And from another
perspective, any "loss "from the target area (i.e., CSL exceedance area) will likely contribute to
enhanced natural recovery in the SQS exceedance area.
Monitoring Cap ThicknessMeasuring the cap thickness directly will be difficult. The expected
accuracy for bathymetric surveys is about 1 to 2 percent of the water depth. In 200 feet of water
this is 2 to 4 feet, assuming aflat bottom surface. The steep bottom slope at the PSR site will
compromise the survey data even further, so using standard bathymetric surveying techniques
would not be an effective tool to measure cap performance (i.e., assuring a cap thickness of
3 feet).
However, Sediment Vertical Profiling System (SVPS) photos could accurately establish the
placement boundary, and direct observations by a Remotely Operated Vehicle (ROV) should
-------
Pacific Sound Resources Record of Decision: Responsiveness Summary September 1999
provide assurance that a relatively uniform layer of material has been placed. The remotely-
operated SVPS drives a prism into the bottom and takes a photograph of up to a 20-cm-high
cross section of the sediment-water interface, depending on sediment characteristics. Where the
cap thickness becomes, less than approximately 20 cm, a distinct layer of capping material
overlying the native sediment is visible. The sampling locations where the cap thickness is found
to be less than 20 cm could serve to delineate the cap boundary. The SVPS was used
successfully to monitor the extent of newly placed material at PSDDA disposal sites at Port
Gardner and Elliott Bay, and at the Superfund site in Eagle Harbor. An RO V was used in Eagle
Harbor to provide video coverage of large areas of the site to visually confirm that the newly
placed material was not being recontaminated by creosote seeping out of bottom sediments. In
addition, the ROY was used to monitoring the cap during construction to detect any problems in
the placement process (such as the disposal of large individual mounds of capping material or
debris). A ROVcould be used in a similar manner at the PSR site. Sediment cores and sub-
bottom profiling can also be used to provide additional information.
The best assurance that an adequate cap thickness can be obtained is the fact that there is an
ongoing supply of nearby capping material from the federal channel in the Duwamish River.
After an initial cap is laid down, it may be possible to achieve additional cap thickness by
allowing disposal of PSDDA materials by bottom dump barge over time. Since the haul distance
to the PSR site appears to be essentially the same as to the PSDDA site, the additional "capping"
could be accomplished at no additional cost (over that of maintenance dredging), and could
continue until all parties were satisfied with the results. However, it should be noted that this
clean material may be needed for beneficial reuse at other contaminated sites and its use would
be prioritized based on a number of considerations, including the potential benefits to the
environment at potentially competing locations.
Monitoring Cap EffectivenessMonitoring of capping projects has included various
techniques, some of which are described in this paragraph. Bathymetric surveys are used to
determine cap thickness as well as changes in thickness. Sub-bottom profilers have been used to
determine the extent to which compaction and subsidence contribute to apparent loss of material
from the cap. These profilers have also been used to assist in evaluating biological activity such
as epifauna in the image area, organism tube density and types, thickness of fecal pellets, and
successional stages (recolonization). Sediment cores obtained through the cap have been used
for a variety of purposes such as determining cap thickness, contaminant migration into the cap,
and depth of biological activity.
Most monitoring has been conducted at capping sites in less than 40 meters of water. Chemical
analyses of sediment cores obtained from sites in Puget Sound and New England have not shown
chemical migration into the cap material. The longest monitoring in Puget Sound has been
11 years at the U.S. Army Corps of Engineers (USAGE) West Waterway CAD site. The interface
between contaminated material disposed at the site and capping sand remained a sharp interface
after 11 years with no indication of contaminants moving into the cap. This same observation
has been made at the St. Paul cap, a shallow water, higher energy site near the Puyallup River
in Commencement Bay, where monitoring has been conducted over the last 10 years. The
USACE New England Division has about 19 years of monitoring data of capped contaminated
material. Results of this monitoring data have shown sharp concentration shifts at the interface
-------
1
Pacific Sound Resources Record of Decision: Responsiveness Summary September 1999
between the caps and contaminated layers, strongly suggesting minimal long-term transport of
contaminants into the caps. However, possible surface contamination of the Eagle Harbor cap
in Puget Sound has recently been identified. To determine whether recontamination is from
surface sources or from the capped contaminated sediments, chemical evaluation of core
sediments is currently being conducted. Monitoring results following a hurricane at a capped
site in the Northeast showed that some erosion of the cap material had occurred. Based on these
monitoring data, additional capping material was placed at the site as a precaution even though
contaminated sediments were not exposed on the surface. This experience demonstrates the
importance of monitoring and managing capped sites.
Recently, contaminated sediment was successfully capped in 74 meters of water. The tools
described above were effectively employed at this site to determine that a cap of the required
thickness was placed over the entire site. Long-term monitoring data have not been obtained
because of the relatively recent establishment of this cap. However, there is every reason to
assume that a cap at this depth, once successfully placed, would be as effective in isolating
contaminated sediments as caps placed in shallower water.
Although steep slopes have not been a factor, PSDDA site monitoring has demonstrated
successful prediction of the bottom footprint for disposal of material in greater than 200 feet of
water. The Corps has experimented with capping contaminated material in 200 feet of water in
Elliott Bay at an old (1976) Waterways Experiment Station site. The site was used to dispose of
PCB-contaminated sediments to monitor open water disposal. The site was capped with
approximately a dozen bargeloads of Upper Duwamish River sand in two cycles of maintenance
dredging (2 dozen loads). Between the first and second cycle, surface grab samples were
collected and evaluated for chemistry. The samples indicated contaminants were below state
clean-up standards (SQS). There are plans to take SVPSphotographs during the next Elliott Bay
PSDDA site monitoring (the site is located partially within the PSDDA site bottom boundary).
This will provide information on the mixing and spread of capping sand being dumped in
200 feet of water. Short-term fate modeling indicated little off-site movement would occur and
the SVPS data will be used to confirm that prediction.
6.2 Geotechnical
Reviewers were primarily concerned that the potential for failure of a cap has not be adequately
evaluated in the FS. There was a specific concern that the conditions assumed in the FS stability
analysis did not account for more catastrophic ground motion. Several agency reviewers were
concerned about the ability to cap on steep slopes or in sloped areas with a finer substrate and
requested that a slope stability analysis or more detailed field investigation of the potential for
cap failure on a slope be performed during the design phase.
Seismic Considerations in Cap DesignSeismic considerations can be factored into the slope
stability programs to produce projected seismic/stability conditions at the site. Any significant
seismic event would tend to flatten the existing slopes to a more stable condition. As a result,
localized areas could experience sloughing and/or thinning of the cap materials. To remedy the
conditions, additional capping materials would need to be deposited at these localized areas. At
a minimum, periodic monitoring of the site would be required with additional monitoring after
-------
Pacific Sound Resources Record of Decision: Responsiveness Summary _ Se tembef /ppp
any significant seismic event. Rehabilitation of the site would require placement of additional
capping materials. Any design cannot protect totally from seismic events the solution i 7 ,
minimize the effects and maintain containment. °" " to tty tO
Two possible solutions to minimizing the effects of seismic events pertaining to cover and
contamment Would be to flatten slopes to maintain integrity and to buiMcLtainment di
prevent migration of materials. However, the latter method would ale
WOUldneed<° be ^^accordingly (i.e..
It would be very difficult to predict the potential sloughing and/or thinning of the cap materials
Capping on Steep (>18 %) Slopes to Ensure Stability-The site shall be evaluated durtnr
design for slope stability for both misting in-situ colons and the capdes^ Characferistic
hasfteslin^ mtatefials.^he loc"ld disP1^ areas may be required based on design
phase testing. Momtonng will be conducted in the short term to evaluate the effectivenes
capping operation and to determine the extent of any downslope migratonofta , SS
1
10
-------
1
Pacific Sound Resources Record of Decision: Responsiveness Summary September 1999
6.3 Cap Thickness
Several reviewers questioned how cap thickness will be determined given the need for chemical
isolation of creosote-eontaminated sediments with a potential groundwater transport pathway and
the potential for bioturbation.
Cap Design Considerations to Achieve Physical, Chemical, and Biological Isolation and
ContainmentThe 3-foot cap thickness utilized in the FS is based on a screening analysis in the
RI Report. The total flux into offshore surficial sediments was calculated, assuming that all
contaminant mass was retained in a hypothetical 1-meter sediment thickness, with no discharge
of contaminants into the Sound, and no degradation of contaminants in the top layer of surface
sediments (i.e.. upper 10-15 cm). This approach identified critical COC's and sediment zones for
recontamination by groundwater, but found that the groundwater contribution is minor
compared to the existing mass in sediments. No assumptions of grain-size or TOC were required
because of the conservative assumption that all contamination would be retained in the cap
material.
During Remedial Design, the cap thickness will be evaluated by methods consistent with
guidance in EPA 905-B96-004, Guidance for In-Situ Subaqueous Capping of Contaminated
Sediments. This manual recommends that recontamination by three primary groundwater
mechanisms be addressed:
A. Expressed porewater from consolidation of underlying contaminated sediments.
B. Diffusion of contaminants from underlying contaminated sediments (for projects
without active groundwater discharge).
C. Discharge of contaminated groundwater through the cap. The contaminated
groundwater may originate from:
1) Dissolved flux from contaminated upland areas.
2) Partitioning from underlying sediments into discharging groundwater.
For Mechanism A, two processes are at work: I) the cap materials consolidate to express
porewater and 2) the underlying sediments/soils consolidate from the weight of the cap materials
and thus express porewater along with any contamination associated with it. Expression of
porewater is dependent on the porosity of the materials and the consolidation of the materials in
both the cap materials and the underlying sediments. Basic soil testing (consolidation and
porosity/permeability) as well as computer modeling can be used to evaluate expressed
porewater during consolidation. Samples of both the cap materials and the sediments are
obtained to conduct this type of testing. If the information is not available, then additional
sampling and testing would be required. Sampling and testing in the RI does not address these
issues and therefore there is not enough information to begin to evaluate whether porewater can
and will be expressed both through the capping materials and the underlying sediments. Further
studies/sampling and testing will be conducted during design to evaluate this potentiality.
Mechanism B can be ignored, since diffusion will be negligible compared to advective transport
associated with groundwater discharge.
11
-------
Pacific Sound Resources Record of Decision: Responsiveness Summary
September 1999
According to the EPA guidance, Mechanism C should be evaluated by an analytical
one-dimensional transport model, to estimate breakthrough times for different cap materials and
thicknesses, based on advection of discharging groundwater with longitudinal dispersion and
partitioning in the cap. The model can also be made to incorporate reasonable decay in the
upper, aerobic portion of the cap. Analytical solutions provided by Ogata and Banks (1961) or
Van Genuchten andAlves (1982) may be used; both are available in EXCEL or MathCAD
format. Mechanisms C. 1 and C.2 both need to be examined by this procedure, because the
sediments underlying the cap may actually release porewater concentrations higher than
groundwater concentrations originating in the uplands OU.
The analytical transport model described above would simulate only the cap material, and
would be in addition to modeling already performed at the PSR site. The BIOSCREEN model
described in the RI Report can be used to provide groundwater discharge rates and
concentrations for input to the sediment cap model. Input data required for the sediment cap
model is shown in Table I.
Table iSediment Cap Input Data
Model Input Data
Cap material gradation
Cap material TOC
Cap material density
Cap material porosity
Groundwater discharge rates
Groundwater contaminant concentrations
Sediment contaminant concentrations
Sediment Kd's
Contaminant Koc's
Contaminant solubilities
Contaminant decay (degradation) rates
Data Source
Test data from anticipated sources
Test data from anticipated sources
Test data from anticipated sources
Test data from anticipated sources
BIOSCREEN model
BIOSCREEN model
RI Report
RI Report
RI Report
RI Report
Published data
The sediment cap design thickness will be adjusted to ensure that contaminant breakthrough
does not occur within the specified service lifetime of the cap. Conservative results may be
obtained by neglecting contaminant degradation in the cap; however, some representative
degradation rates may be obtained from literature sources, or from studies at other projects such
as Eagle Harbor.
12
-------
Pacific Sound Resources Record of Decision: Responsiveness Summary September 1999
Subtidal benthic communities inhabiting Elliott Bay exhibit higher abundance and species
richness in shallower environments. Word et. al. 19841, in a study in Elliott Bay found a
decrease in numbers and abundance of benthic taxa with increasing depth. Therefore cap
thickness in the shallower nearshore areas (< 100 feet), should provide a thickness sufficient to
provide a chemical and biological barrier to recolonizing benthos (3 feet), including
bioturbating species such as Molpadia intermedia (infaunal holothurian) and Callianassa spp.
(burrowing shrimp) known to inhabit Elliott Bay. The Denny Way CSO capping project
documented Callianassa spp. densities of8-10/m2 within six months of capping and densities of
38-66/m2 within eighteen months of capping in water depths from 20 to 60 feet. Densities of
Callianassa spp. observed at eighteen months at the Denny Way CSO are capable of effectively
turning over up to 1.2-5.4 kg/m^day2 of sediment. Other taxa such as Molpadia spp. can also
cause significant biogenesis and vertical transport of sediment (as a conveyor belt species)
through their feeding activities (Rhoads and Young 19713; Lee and Swarz 1980)4.
6.4 Cap Source Material
Reviewers raised several pertinent issues regarding the source of the capping material and the
timing of the placement. Most reviewers were looking for options that minimized the material
costs by timing the cleanup to coincide with the availability of maintenance dredged materials.
The proximity of the Federal project in the Duwamish River makes Corps' maintenance
dredging material the most logical source of capping material. If cap placement methods
utilized readily available dredging equipment, (similar to the placement methods used in Eagle
Harbor), only minor modifications to routine maintenance dredging contracts would be
required, and capping cost would be minimal. The PSR Superfund Project would have to pick up
only the incremental increase in the disposal cost over open water disposal at the Elliott Bay
PSDDA site. For this reason, every effort should be made to adjust the "estimated time to
cleanup " to the Duwamish maintenance dredging volumes and schedule.
Maintenance dredged material from the Federal channel in the Snohomish River is an
alternative source of capping material, but at an increased cost. Obtaining capping material
from a marine borrow source is not recommended due to adverse environmental impacts. A
1 Word, J. Q., et. al., 1984. Subtidal Benthic Ecology. Final Report. Vol. V, Section 6. In: Q. J. Stober and K. K.
Chew, Principallnvestigators. Renton Sewage Treatment Plan Project: Seahurst Baseline Study. University of
Washington Fisheries Research Institute.
Lee and Swarz (1980) estimated Callianassa californiensis can individually rework sediment at a rate of 33 to
82.5 g/individual/day down to a sediment depth of 76 cm (see citation below at 4).
3 Rhoads, D. C. and D. K. Young. 1971. Animal-sediment relations in Cape Cod Bay. Massachusetts. II.
Reworking by Molpadia oolitica (Holothuroidea). Marine Biology. 11: 255-261.
Lee. H. and R. C. Swarz. 1980. Chapter 29. Biological processes affecting the distribution of pollutants in marine
sediments. Part II. Biodeposition and Bioturbation. In: Contaminants and Sediments. Volume 2. edited R. A.
Baker, pp. 555-606.
13
-------
1
Pacific Sound Resources Record of Decision: Responsiveness Summary
1090
viable borrow source probably would have to be located in water depths of -20 to -40 feet
MLLW. Assuming a borrow volume of 8 50,000 cubic yards and a dredge cut of 10 feet the
borrow site w.ould remove all benthic organisms from approximately 52 acres of bottom lands
bet\veen-20to-40feetMLLW.
The use of an upland source for capping material would increase capping costs by more than an
order of magnitude, clearly less desirable.from an economic standpoint. In 1994 the Corps of
Engineers estimated the cost of placing additional capping material at Eagle Harbor. The cost
for sand, obtained from an upland source, and placed hydraulically, was $11/cubic yard. In
November 1994, the Corps placed approximately 5,000 cubic yards of sand and gravel at
Seattle's Lincoln Park as part of a beach nourishment project. This material cost $24/cubic
yard. The cost for the initial placement of the capping material (by washqff) at Eagle Harbor
was $2.42/cubicyard, including a 60-mile round trip haul from the Snohomish River The cost
of capping with material obtained from an upland source appears to be between 4.5 to 10 times
the cost of material obtained from maintenance dredging.
6.5 Cap Placement
Reviewers provided technical information about possible methods of cap placement that need to
be further evaluated during design. Some methods will require field tests prior to selection
which would .need to be incorporated into the design schedule.
Placing a cap of clean material over contaminated bottom sediments at the PSR Superfund site
does not appear to be technically difficult. Placement methods previously utilized in Puget
Sound. (Denny Way CSO and Eagle Harbor) have demonstrated that a relatively uniform layer
of dredged material can be gently placed over large areas of contaminated sediments While the
PSR site is in much deeper water, 200 feet versus 30 to 60 feet, the quiet, low energy nature of
the PSR site should result in only an extended settling time for the capping material The
greatest challenge may be in developing a placement plan that most economically utilizes the
available capping resources.
Hydraulic placement methods could be used to gently place a layer of dredged material in a
relatively shallow portion of the area to be capped. This area could then serve as a disposal site
within which the standard bottom dump barge disposal method is utilized. Material placed by
this method would flow down the steep bottom slope and cover the deeper contaminated
sediments. Since the haul distance to the PSR site and the existing PSDDA site are essentially
the same, the construction cost for a significant portion of the PSR capping project could
potentially be eliminated.
A numerical model developed at the Waterways Experiment Station, STFATE, is used to predict
the short-term fate of dredged material disposed in open water. This model does have the
capability to represent the effects of the bottom slope. It may be possible to "verify " the model
by comparing model results with monitoring data from the Elliott Bay PSDDA site. However a
pilot test is probably the only "sure" way to determine if standard the bottom dump procedure
will produce satisfactory results.
14
-------
1
Pacific Sound Resources Record of Decision: Responsiveness Summary September 1999
The following Elliott Bay capping projects have successfully placed material on slopes by slowly
releasing (sprinkling) from bottom dump barges at about 27 cubic yards/minute.
Project Average Slope Maximum Slope
Denny Way CSO 13% 29%
Piers 53-55 Cap 15% 33%
Pier 64 Cap 20% 50%
By comparison, the PSR MSU has an average slope of 5.1 percent, with a maximum slope of
21 percent.
6.6 Life/Duration
Several reviewers were concerned that the design life evaluated in the FS didn't realistically
address the actual longevity needed for the remedy.
While the FS utilized 30 years for cost evaluation and alternative comparison purposes, the
actual life of a sediment cap can be indefinite if properly designed and managed. The following
bullets discuss some of the major elements of a long-term site management program.
Development of an effective monitoring program. Implementation of monitoring during
and after construction to insure that the cap is placed as intended and that the cap is
performing the basic functions (physical isolation, sediment stabilization, and chemical
isolation) as required to meet the remedial objectives. It is important to insure
implementation of the monitoring program after major events such as unusually strong
storms and earthquakes.
Long-term management of data with reporting of conditions and results. This is crucial
since the site manager may change over an extended period of time.
Designation of contingency plans if monitoring indicates that the cap is not meeting the
remedial objectives. These may include, but not be limited to, placement of additional
capping material or modifications to the cap design including placement techniques.
Identification of additional capping material source(s). Coordination between the site
manager and the source of cap material should also be conducted.
6.7 General Issues
Reviewers raised a number of other issues that may affect the design of the remedy. Issues
included the need to confirm the potential contaminant mounds on the bottom and incorporation
of that information in the design of the cap, capping in the higher energy nearshore areas,
impacts of capping on local current movement and sediment transport, capping phasing and
duration, compatibility of the grainsize of the capping material with underlying sediments or as
benthic habitat, evaluation of innovative engineering techniques for construction of a cap on a
slope, and effectiveness of new dredging technologies.
15
-------
Pacific Sound Resources Record of Decision: Responsiveness Summary
'.ptember 1999
EPA recognizes that more information will be needed to design and implement the remedy at the
site and anticipates an additional data gathering or testing phase at the beginning of the design
process. EPA believes that there are adequate data available to provide reasonable confidence
that a cap will be effective in addressing site risks. However, as with all technologies, there are
uncertainties associated with certain performance functions of the cap. EPA will evaluate the
need for a capping test prior to design to provide data to resolve the uncertainties with a
proposed cap.
7. COST EFFECTIVENESS
Reviewers questioned how costs were integrated into the selection of the proposed remedy In
addition, questions were raised regarding how costs were compared among the alternatives
There was also some confusion because cleanup and disposal costs were presented separately.
Cost information in the FS is used as one criterion in selecting the preferred alternative Cost is
factored into the alternative evaluation with the other evaluation parameters as set forth in the
NCP. Overall Protection of Human Health and the Environment and Compliance with ARARs
must be met; all other criteria (including Cost) are balancing criteria, after the first two are
achieved. In the FS, each alternative was ranked based on a cumulative ranking of? of the 9
CERCLA criteria (State and Public Acceptance were not considered), in order to frame how the
criteria may affect a remedy. No single criterion was used to select the preferred alternative.
Generally, an alternative is cost effective if it provides a similar or greater level of protection
other alternatives at a similar or lower cost. Additionally, an alternative is cost effective if,
increase in cost returns an equal or greater increase in benefit compared to the other
alternatives.
as
an
There are no specific criteria under CERCLA that indicate when an alternative is not cost
effective. Ecology's cleanup guidance suggests that costs that deviate more than 10 percent are
significant. Costs for the proposed cleanup alternatives ranged from $5.5 to $12.4 million; with
disposal (assuming construction of a near shore disposal facility) costs ranging from $8.2 to
$11.4 million. These costs are within the range of cleanup costs at other sites within Puget
Sound; all alternatives considered for detailed evaluation in the FS have some degree of cost
effectiveness.
Costs for removal or capping were considered separately in the FS because of the difficulty in
siting an in-water disposal facility or upland dewatering facility. However, all information was
presented such that different cleanup alternatives could be considered with each disposal option.
8. SOURCE CONTROL AND POTENTIAL FOR RECONTAMINATION
Overall, reviewers were concerned that all source control measures are in place prior to
implementation of the remedy. Specifically, they were interested in what source control actions
will address the potential releases from Longfellow Creek, the uplands, the groundwater
16
-------
Pacific Sound Resources Record of Decision: Responsiveness Summary September 1999
discharge zone, and the Lockheed and Crowley Marine Services facilities. Reviewers also
requested clarification of the contingency planning process if recontamination does occur.
Source control has been accomplished to the extent practicable for this site. Numerous actions
have been taken to control releases from the Upland Unit of the site. The wood treating facility
has been demolished and source material (sludge and highly contaminated soil) has been
removed. A subsurface wall around the north end of the Upland Unit prevents the migration of
shallow (less than 45ft below ground surface) groundwater, DNAPL andLNAPL to Elliott Bay.
DNAPL has been pumped from all wells where it has been detected and has shown a significant
reduction in volume over time. An impermeable cap is in place over the entire 25 acre site. In
addition, the Port of Seattle cleaned out the Longfellow Creek overflow pipe and dredged a small
volume of sediment at the mouth of the outfall to remove contaminated sediments.
The MSU RI evaluated the potential for groundwater to transport dissolved constituents from
NAPL in the Upland Unit to the sediments. The model indicated that an area near Crowley
Marine has the potential to be recontaminated at low levels over time for selected PAHs.
However, the model assumptions used were very conservative and did not account for all
processes that could serve to retain or degrade PAHs in groundwater prior to reaching surface
sediments. While the potential for recontamination of a clean cap in that area from groundwater
discharged to the marine environment is unlikely, it cannot be ruled out entirely. Long-term
monitoring will be designed to detect recontamination, if it should occur. If the remedy for any
reason, should prove deficient, action plans will be developed with input from the trustees and
agencies to remedy any such contingency.
9. NATURAL RECOVERY
Several reviewers felt that natural recovery should be evaluated as part of the remedy.
Specifically, they were interested in whether the areas currently above the SQS would fall below
the SQS within a 10-year time frame.
EPA completed a preliminary evaluation of the potential for natural recovery of the PSR MSU
based on data collected as part of the Harbor Island Remedial Investigation, and the Seattle
Waterfront Recontamination Study. Sedimentation rates in the southwestern portion of Elliott
Bay are unlikely to be sufficient to achieve natural recovery at the site. Accordingly, active
remediation rather than natural recovery is the main component of the proposed remedy. EPA
has discussed the potential for enhanced natural recovery in the areas bordering the cap area
with a number of Trustee and regulatory reviewers. It is anticipated that there will be some
amount of transport of capping materials to non-target areas due to the inaccuracies inherent in
cap placement at depth or on steep slopes. It is difficult to estimate the amount of area that may
undergo "enhanced natural recovery" via this process.
10. RAOs/EVALUATION CRITERIA
The primary concern expressed by the reviewers was whether the RAOs selected for the MSU
were sufficiently protective of human and fish health. Another concern raised was how the
17
-------
inCOrp°rated in
-------
1
Pacific Sound Resources Record of Decision: Responsiveness Summary September 1999
result in a human health excess cancer risk of less than 1 in 10,000 and a noncancer
hazard index of less than 1.0 (Overall Protection of Human Health and the Environment,
Compliance with ARARs)
A numerical ranking was used to summarize the evaluation of the alternatives. This approach
allows for a less subjective understanding of how one alternative compares to another. The
evaluation text alone is adequate for selection of an alternative, however, EPA felt it would be
beneficial to provide the numerical ranking to let the reader know how each compared to the
others. Overall Protection of Human Health and the Environment and Compliance with ARARs
are two criteria that must be met; all other criteria are considered balancing criteria, when the
first two are achieved. In the FS, each alternative was ranked based on a cumulative rank of 7
of the 9 criteria (State and Public Acceptance were not considered). Rankings were assigned a
value of I through 5 (there were Jive alternatives evaluated other than No Action). An
alternative was ranked based on the information provided in the text (if one alternative better
met the criterion under evaluation, it was given a higher rank; those with similar effectiveness
shared ranks). See Appendix G of the FS for specific rankings.
11. MONITORING
Reviewers were concerned that the monitoring cost estimates were not reasonable for a site this
deep. This concern was raised in part based on the Corps' experience with the Eagle Harbor
capping project. Most reviewers also felt that a greater level of effort and longer duration would
be required for the actual long-term monitoring program.
EPA believes that FS monitoring costs are adequate for the purpose of proposing a remedy. The
estimate based on the monitoring scheme presented in the FS was not intended to serve as the
final monitoring plan for the site. Rather, the monitoring scheme was intended to provide some
basic monitoring elements to allow comparisons among alternatives. The actual monitoring
program will be developed during design and will be available for review prior to
implementation. It is likely that actual long-term monitoring will occur on a more frequent basis
or with greater level of effort per event, depending on the final characteristics of the remedy and
monitoring techniques that will be most effective.
EPA understands that the cap or disposal site may need monitoring beyond a period of 30 years.
However, EPA guidance recommends use of 30 years for comparative purposes.
If costs were modified to address reviewers comments (see example below), the impacts to costs
across alternatives would be similar (i.e., relationships among alternatives would stay the same).
The following assumptions were used to create the recosted example.
Monitoring occurs for 100 years on the following years: 1, 2, 3, 5, 7, 10, and every 5 years
thereafter out to 100 years.
The cost for a single monitoring event is double that in the FS. The following table shows
the recalculated monitoring cost versus the FS cost.
19
-------
Pacific Sound Resources Record of Decision: Responsiveness Summ^,
Table 2-Modified Costs .ncorporating Revised Assumptions for Long-term Monitoring
im^*rcp""*"*^^^^»gg=-^»^~^'i'*-^^^-^--, i i
12. DISPOSAL/SITING
\
13. RESTORATION GOALS
20
-------
Pacific Sound Resources Record of Decision: Responsiveness Summary September 1999
sufficient protection offish resources. During a subsequent meeting with EPA, the Trustees
further clarified that this goal applied to any depth (i.e., not just the nearshore) and should be met
on a point-by-point basis, as opposed to an area weighted average. In addition, their goals
included removal of all pilings from the nearshore area and no net loss of habitat.
EPA has evaluated how to achieve the Trustee PAH restoration goal for the PSR MSU.
Immediately following capping, total PAHs will likely be at or below the restoration goal over
47 acres of the site. Additional areas near the boundary of the capped area may also meet the
goal due to loss (estimated 25% of total cap volume) and migration of clean capping material
during placement in deep water or along steep slopes. Modeling can be performed during the
design phase to estimate which areas may be positively affected; however, this benefit cannot be
confirmed until post-remediation monitoring takes place. Areas outside of the capped area will
likely have total PAH concentrations above the restoration goal but below the CSLfor individual
PAHs based on current conditions (see Figure I).
With respect to the remaining restorations goals, the proposed remedy will not result in loss of
any aquatic habitat, and all pilings that are not in use will be removed from the marine
environment.
14. EDITORIAL COMMENTS
The following editorial comments were provided to EPA; however, the Feasibility Study and the
Proposed Plan documents will not be revised. The Record of Decision and responsiveness
summary will incorporate editorial comments, where specific materials (tables, figures or
appendices) are included.
D3a. DNR would like to request that the products being offered for public review and
comment clearly identify the public-aquatic lands within the site boundaries. It is critical
for the public to understand that the decisions being made at the site have specific
implications for the citizens of this state.
A2. Suggest removing any "recommendations" that specify and/or constrain the methods of
sediment cap placement sequencing or details of construction methods, unless they have
a sound engineering or environmental basis. See related specific comments below.
A3. Suggest that a list of all the acronyms appearing in this document be prepared and placed
in the front, following the table of contents.
A50. Page 1-1, second paragraph, first sentence. "The purpose of this report is to provide
EPA, other interested agencies...." The FS should be by EPA, not directed to EPA.
WESTON may have prepared it, but under the direction of EPA, making it EPA's report.
T6. Page 1-2, first paragraph. The phrase "to the extent practicable" should be changed to
"to the maximum extent practicable" to conform to the Model Toxics Control Act
(MTCA) cleanup regulation language (Chapter 173-340, WAC).
21
-------
1
Pacific Sound Resources Record of Decision: Responsiveness Summary September 1999
A52. Page 1-3, Section 1.3, first paragraph, numerous citations of WESTON documents.
Are these EPA documents or WESTON documents? If they are WESTON documents,
what role does WESTON play in the decision making process? Likewise, all of the
RETEC citations should be 'Port of Seattle.' It is my understanding that all of these
reports were prepared for and under the control of a government entity. It is the
government entity that takes responsibility for the report, and therefore, should be listed
as the source of the report.
T8. Page 1-4, Section 1.3.2, third paragraph. Please change the phrase "treaty rights to
gather shellfish" to "treaty rights to gather other fish and shellfish." Also, please delete
the last sentence in the paragraph, and the associated Figures 1-7 and 1-8. The figures are
inaccurate and the previous sentences in the paragraph adequately state that the Tribes
fish in the area.
T10. Page 1-8, Section 1.4.6, second paragraph, fourth line. Please change the first word in
this line from "estuary" to "Waterway."
A53. Page 1-12, Section 1.5.2 (Biota), first paragraph, second sentence. 'Some of these
species....' EPA should provide a list or a table of those species of concern and their
status (Federal or State listings).
Ml9. Page 1-12, last paragraph. Chinook have now been listed, and various references to it
throughout the report should be updated.
T13. Page 2-2, first full paragraph. This paragraph should clearly state that the SQS and
CSLs are Washington State-derived numbers. The term "biological resources" should
also be replaced with "benthic infauna."
E15. Page 2-2 Section 2.2.1.1, second paragraph. Insert as second sentence "However, the
SMS does have a narrative standard for human health of no significant health risk to
humans."
T14. Page 2-2, Section 2.2.1.1, second paragraph. Insert the following as a second sentence:
"However, the SMS does have a narrative standard for human health of no significant
health risk to humans."
E16. Page 2-2 Section 2.2.1.1, third paragraph. The wording discussing the difference
between CSL and AETs is too confusing. Simply put, the only difference is that SQS and
CSL are TOC normalized, AETs are dry weight normalized.
A7. Page 2-4, Section 2.3.1, last paragraph, third sentence. Data generated from the clam
bioaccumulation and fish tissue study used to support the human health risk assessment
should be summarized and provided in an appendix to this report.
A55. Page 2-10, Section 2.4.3.1. Change the last sentence to read 'EPA consults with
Department of Interior on remedial actions to assure appropriate consideration of
threatened and endangered species.'
22
-------
Pacific Sound Resources Record of Decision: Responsiveness Summary September 1999
T18. Page 2-10, Section 2.43.1, last sentence. Please replace the phrase "from the
Department of the Interior" to "from the Department of Interior and/or the Department of
Commerce, acting through the U.S. Fish and Wildlife Service and the National Marine
Fisheries Service, respectively."
T19. Page 2-10, Section 2.43.3, Title. Please remove "U.S." from Fish andWildlife
Coordination Act.
A57. Page 2-12, Section 2.6, last paragraph. Change 1st sentence reference from 'WESTON'
to 'EPA.'
M27. Page 3-1, bullet. This paragraph should be rephrased so that it does not state that "no
action/institutional controls" will meet the project RAOs.
A8. Page 3-3, first paragraph, fourth sentence. Strike "on" between "CAD sites" and
"with greater., in situ."
121. Page 3-3, first paragraph, fifth line. Please change the sentence that starts with "Some
CAD sites on with" to "Some CAD sites with."
A9. Page 3-4, fifth paragraph, first sentence. "Institutional Contracts" should be changed
to "Institutional Controls".
A58. Page 3-4, Section 3.2.3. This appears to be an alternative, not a technology. I would be
careful here to not start mixing a technology evaluation with an alternatives analysis. I
recommend moving this entire section to Section 5.
A12. Page 3-7, paragraph 3.3.3.2, next to last sentence. Figure 4-12 should be referenced in
text to denote location of two CAD sites.
A59. Pages 4-1, Section 4.1.1. This is good detail on dredging but we believe a summary
would work fine in this section, with the details put into an appendix (Sections 4.1.1 to
4.1.1.5). This would make the document a bit more readable by the general public.
)
A14. Page 4-2, third paragraph. In the last sentence, should replace "a barge" with "one or
more barges".
M28. Page 4-5, first paragraph. The prevailing winds may be from the southwest, but the
winter storms that generate the most wave action are typically from the north.
T22. Page 4-5, Section 4.1.2. second paragraph, last sentence. Due to the explanation
immediately preceding this sentence, the last sentence should read "Most slopes within
theMSU...."
A21. Page 4-6, Section 4.1.2.2, last two sentences. The basis for these statements is unclear.
I believe that specifying and/or constraining the sequence or details of the method of
placement may be premature. I suggest that these two sentences be removed.
23
-------
Pacific Sound Resources Record of Decision: Responsiveness Summary September 1999
A24. Page 4-7, last paragraph, first sentence. I suggest that this sentence be revised from
shoreline would require.... to read shoreline may require
A28. Page 4-8, first paragraph. See Comment A21 above.
A61. Page 4-8, Section 4.1.2.3 (Capping Summary), second paragraph, second sentence
Change dredge spoils to dredge materials.
T24. Page 4-11, Section 4.1.5.1, last paragraph. On the second line, please change the
beginning of the third sentence to "If conditions allow, sampling frequency would then be
decreased..."
A32. Page 4-13, last paragraph, last sentence: I believe that specifying and/or constraining
the sequence or details of the method of placement may be premature. I suggest this
sentence be removed. See General Comment A2.
T26a. Page 4-17, Section 4.2, second paragraph. Remove sentence four, since it is debatable
that other less-expensive technologies would provide the same level of
protectiveness..." (emphasis added).
T27. Page 4-18, Section 4.2.2, third sentence. Include a statement that allows for dredging of
shoreline or areas close to shore in which shore protectiveness and slope instability are
not issues.
A37. Page 4-20 to 4-22. Figures 4-7, 4-8, and 4-10 do not clearly elucidate the demarcations
for the capping sequences. The line symbols used (at least in my copy) were
indistinguishable between phase 1 and phase 2.
A38. Page 4-22, third paragraph, last sentence. Add "foot depths" between " 150" and
'offshore".
A45. Figure 4-12 should also note the location of the WES experimental dump site relative to
the PSDDA site and potential CAD site 1 boundaries.
A63. Page 5-1, Section 5. I recommend using the language directly from 40 CFR 300 to
present the purpose of the alternative analysis. For example:
'This section contains a detailed analysis of viable approaches (as
identified in Section 4) to the remedial action at the PSR MSU.
The detailed analysis consists of an assessment of individual
alternatives against each of the nine evaluation criteria (listed
below) and a comparative analysis that focuses upon the relative
performance of each alternative against those criteria.'
A65. Page 5-1, Section 5.2 (Analysis Criteria). I recommend changing this to 'Evaluation
Criteria' to be consistent with the 40 CFR 300.
24
-------
Pacific Sound Resources Record of Decision: Responsiveness Summary September 1999
A66. Page 5-1, Section 5.2. I recommend explaining all nine criteria, then note that EPA will
evaluate the last two upon their selection of the preferred alternative. I also recommend a
short paragraph on how EPA considers the nine criteria (threshold, balancing,
modifying).
A41. Page 5-12, Section 5.3.3.5. Discuss seismic failure risk further in this section.
T39. Page 5-14, Section 5.3.4.2, first paragraph, fourth line. Please change "CLS" to
"CSL." (typographical error).
A84. Page 5-18 through 5-29, Section 5.4. I believe that it confuses the record to treat these
as actual separate alternatives (See Comment A71). Instead of providing a page by page
review of these alternatives, I believe all of the detailed comments for the previous
alternatives are applicable to these sections.
T40. Page 5-23, first paragraph. The Trustees suggest deleting the sentence that states, "The
area lost, however, is currently highly contaminated, providing low-quality habitat for
fish." This sentence is not needed in the paragraph, and is not necessarily accurate. This
paragraph should also note that habitat mitigation would likely be a requirement of this
disposal alternative.
T41. Page 5-25, first full paragraph. The Trustees suggest deleting the following from the
paragraph: "that now provide low quality habitat for native marine communities. The
present ecological values of these sites are limited by existing contamination." See the
explanation in the previous comment.
T42. Page 5-25, Section 5.4.2.6, third paragraph, sixth line. Please delete the following:
"The area lost, however, is currently contaminated and provides low-quality habitat for
fish. In addition,". See the explanation in the two previous comments.
25
-------
-------
FIGURES
-------
-------
f/,'iv(i=:',
,*. v; i
'\ ;' ' "
'- -."%, -^1
: '\ ,;: i
i
""*" i1*'"" CHECKED BY:
Cotactod far AntW (nTil)
O Ph*M 3 EurteOA S«dlrnam CoRectad tor
« PhM*2SurfK»(Olaiacni)S«dlnwm
StMkxi -Ownlniyonv nwT]
(0 l?mcm> OwnlMy (n - 9)
Pr»»28urta»(Ota10cm)S«ftn*nt
SOUan -CtwinMiyand/vFMi
lmmi,giomay« (n - 261
A Ph«M2Surho*n)Sadim«nt
StaUan - FWd hnmunouny
OnV(n-25)
x PtwMlSurfm(Olii10cm)SwJ)menl
Simple - Ctombtiy Only (n - 45)
44MO1-013*
w
APPROVED BY-
G
SC
100 0
-
X MK
V
ALEI.i.00
00 200 300 40
3HW=MBB
Rwl
<^
0 PSRSIft
nans i
DCooamnliontiionMludtyweloM. i
2) Surface Sediment '
PSR Marine Sediments Unit
NOAA Total PAH |
i
Tl
-------
-------
RESPONSES TO SPECIFIC COMMENTS
ON THE PSR MARINE SEDIMENTS UNIT FS AND PROPOSED PLAN
-------
-------
DEPARTMENT OF THE ARMY
SEATTLE DISTRICT, CORPS OF ENGINEERS
P.O. BOX 3755
SEATTLE, WASHINGTON 98124-3755
REPLY TO
ATTENTION OF
May 13, 1999
Environmental Management Branch
Ms. Sally Thomas
U.S. EPA, Region 10
1200 Sixth Avenue
Seattle, Washington 98101
SUBJECT: Review Comments for Draft Feasibility Study (Nov 98) and Proposed Plan (Apr 99), Pacific
Sound Resources Superfund Site, Elliot Bay, Washington
Dear Ms. Thomas:
Submitted with this letter are the Seattle District, U.S. Army Corps of Engineers comments on
the Draft Feasibility Study (November 1998) and the Proposed Plan (April 1999). The comments were
focused on identifying issues related to: 1) Alternatives Analysis and Clean Water Act Section 404(bX 1)
Evaluation and 2) Engineering considerations for future remedial design/remedial action (RD/RA). I
look forward to meeting with you to discuss these comments.
If you have any questions, please call me at telephone (206) 764-6682.
Sincerely,
Ralph J. Totorica
Project Manager
Enclosure
-------
-------
U.S. Army Corps of Engineers Comments
Draft Feasibility Study (November 1998)
Pacific Sound Resources Marine Sediment Unit
I. Engineering Considerations for RD/RA:
General Comments:
Al. The following general comments are submitted regarding the cap thickness and
recontamination issues discussed on p. 4-15. This may not require resolution for the FS,
but is worth bringing up for consideration by EPA:
The 3-foot cap assumption is probably good for the purposes of the FS alternative
evaluation, however the actual thickness should be evaluated during the design analysis
per guidance in EPA 905-B96-004. This manual recommends that recontamination by 3
primary groundwater mechanisms be addressed:
1. Expressed porewater from consolidation of underlying contaminated sediments.
2. Diffusion of contaminants from underlying contaminated sediments (for projects
without active groundwater discharge).
3. Discharge of contaminated groundwater through the cap. The contaminated
groundwater may originate from:
a) Dissolved flux from contaminated upland areas.
b) Partitioning from underlying sediments into discharging groundwater.
Modeling in the RI appears to addresses only mechanism 3b). The total flux into offshore
surficial sediments was calculated, assuming that all contaminant mass was retained in a
hypothetical 1-meter sediment thickness, with no discharge of contaminants into the
Sound, and no degradation of contaminants in the top layer of surface sediments (i.e.
upper 1(M5 cm). This approach identified critical COC's and sediment zones for
recontamination by groundwater, but noted that the groundwater contribution is minor
compared to the existing mass in sediments.
According to the EPA guidance, mechanism 3) should be evaluated by an analytical ID
transport model, which would estimate breakthrough times for different cap materials and
thicknesses, based on advection of discharging groundwater, with longitudinal dispersion
and partitioning into the cap. The model can also be made to incorporate reasonable
decay in the upper, aerobic portion of the cap. Both 3a) and 3b) need to be looked at by
this procedure, because the sediments underlying the cap may actually release porewater
concentrations higher than groundwater concentrations originating in the uplands OU.
-------
The results of analyses for 3a) and 3b) will determine cap thickness required to prevent
recontamination.
See Section 6.3 (Design IssuesCap Thickness) of the Responsiveness Summary.
A2. Suggest removing any "recommendations" that specify and/or constrain the methods of
sediment cap placement sequencing or details of construction methods, unless they have a
sound engineering or environmental basis. See related specific comments below.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A3. Suggest that a list of all theacronyms appearing in this document be prepared and placed
in the front, following the table of contents.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A4. The FS lacks a discussion of natural recovery processes as they might attenuate sediments
in SQS contaminated areas, which are outside the proposed active remediation footprints
for alternatives 2, 3b, and 4b. The FS should summarize the results of a "natural
recovery" analysis (e.g., "WASP" modeling) relative to achieving natural attenuation
(sedimentation) of PAH contaminated sediments below SQS levels and the potential
timeline for achieving SQS. For the "no action alternative, the FS text @ page 5-4 (last
sentence) and top of page 5-5, acknowledges that natural recovery processes are possible,
but does not quantify how effective this process may be as an adjunct to active
remediation of the CSL contaminated sediments (e.g., alternatives 2, 3b, and 4b) to
achieve the ultimate cleanup goal of SQS. Also, explicit monitoring of the SQS
contaminated areas needs to be part of the long term monitoring plan to monitor the
natural attenuation progress following cap placement.
See Section 9 (Natural Recovery) of the Responsiveness Summary.
A5. Monitoring costs for the cap appear to be low for a site this deep. For example,
monitoring of the Eagle Harbor cap, at a depth of 40 feet, is estimated to cost L5 million
dollars over a ten year period. In addition, extensive monitoring was required during cap
placement. Since PSR is much deeper, monitoring is more difficult and expensive.
Monitoring data and cost data are available concerning the Elliott Bay PSDDA site which
is 300 ft. In fact, data from the PSDDA site could provide valuable information
concerning the behavior of dredged material at deep sites.
See Section 11 (Monitoring) of the Responsiveness Summary.
A6. The New England District of the Corps of Engineers recently conducted a capping
demonstration at a 200 ft site. The project included the formation of a mound using fine
grained material and capping the mound with coarse material. They have been
monitoring the site since the disposal activity. Results demonstrate that a successful cap
was placed over the fine grained material. Extensive monitoring including bathymetry,
side-scan sonar, sediment profiling camera, as well as grab and core sampling was
-------
conducted. This project would be an excellent source of information relevant to the PSR
project.
See Sections 6.2 (Design IssuesGeotechnical) and 6.3 (Design IssuesCap Thickness) of the
Responsiveness Summary.
Specific Comments:
A7. Page 2-4, paragraph 2.3.1, last paragraph, third sentence. Data generated from the clam
bioaccumulation and fish tissue study used to support the human health risk assessment
should be summarized and provided in an appendix to this report.
Clam and fish tissue data were provided as part of Appendix K in the RI report.
A8. Page 3-3, first paragraph, fourth sentence. Strike "on" between "CAD sites" and "with
greater., in situ."
See Section 14 (Editorial Comments) of the Responsiveness Summary,
A9. Page 3-4, fifth paragraph, first sentence. "Institutional Contracts" should be changed to
"Institutional Controls".
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A10. Page 3-6, third paragraph. More information should be provided on the Eddie Pump
high energy Vortex dredge, which should include a schematic or figure showing what it
looks like in an appendix to assist the reader in evaluating this particular type of dredge,
particularly since there is a lack of experience in the use of this dredge in the northwest
and its use to dredge deeper than 50 feet MLLW (historical dredging depth limit) down to
200 feet MLLW.
See Attachment 3 and response to Comment A18.
Al 1. Page 3-^_3ri Paragraph. It is stated that the Eddie Pump can be equipped to dredge at
depths of 150 to 200 feet. Please indicate where it has been demonstrated successful at
these depths.
See Attachment 3 and response to Comment A18.
A12. Page 3-7, paragraph 3.3.3.2, next to last sentence. Figure 4-12 should be referenced in
text to denote location of two CAD sites.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A13. Page 3-8, first paragraph, last sentence. The $ 110 per cubic yard cost quoted for
Roosevelt Landfill seems way out of line, especially since the Bellingham Pilot Study
-------
1
of S3° percuwc *"" fr°m "
This estimate is an all inclusive estimate thai includes devote, handling ,hinnin<, j
h°Uld rep'aCe "a bar«e" wi"> "o- or more
Section 14 (Editorial Comment) of the Responsiveness Summary.
5-ee &*/«, 5. 7 H ««- es) of the Responsiveness Summary.
- Differential global positioning system (DGPS) units
5ee Section (J.7
are
o/rte Responsiveness Summary.
"
^
dredges for remediation of the Palos Verdes shelf in southern CaliZ ia The
-------
Performance data from a recent small test dredge is provided in Attachment 3.
Operation of the EDDY PUMP dredge at depths off 200 feet has not been demonstrated.
However, because the EDDY PUMP is suspended on the end of a cable, it has much deeper
capabilities compared to ladder type cutter head dredges. Factors limiting the depth of the
EDDY PUMP dredge are the length of the cable and the pumping capabilities of the pump. The
manufacturer has indicated that their pumps can produce up to 400 feet of head -which would
allow dredging at depths of 200 feet. A booster pump may be needed to pump the sediment once
it reaches the surface to the disposal site.
Steve Scott at WES just witnessed a test dredge with the EDDY PUMP. Steve indicated that he
thinks the pump will pump up to 40% solids. He feels the EDDY PUMP has a lot of potential but
has not seen any pump curves or other documentation that shows the pump has enough head to
move the material from a depth of 100 to 200 feet to a distant disposal site. He also said he
believes the output of the pump may be a little exaggerated. He did say however, that the setup
of the EDDY PUMP has no depth limitations assuming there is adequate head to move the
dredged material. That is, it's only depth limitation is the length of cable on the dredge crane.
See Section 6.7 (Design IssuesGeneral Issues) of the Responsiveness Summary.
A19. Page 4-5, third paragraph. The text should also note that additional cover in nearshore
areas out to 100 foot depths will be needed to insure a final cap thickness of 3 feet, and
not just in proposed capping areas deeper than 100 feet. Concerns about bioturbation by
deep burrowing organisms are generally more significant in the shallower areas less than
100 feet, where contamination levels are greater and natural resource concentrations are
generally higher.
See Sections 6.2 (Design IssuesGeotechnical) and 6.3 (Design IssuesCap Thickness) of the
Responsiveness Summary.
A20. Page 4-5, Section 4.1.2.1. It should be noted that the Snohomish and Duwamish sources
have been successfully used in the past and provide controllable sand gradations.
See Section 6.4 (Design IssuesCap Source Material) of the Responsiveness Summary.
A21. Pg. 4-6, para. 4.1.2.2, last two sentences: The basis for these statements is unclear. I
believe that specifying and/or constraining the sequence or details of the method of
placement may be premature. I suggest that these two sentences be removed.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A22. Page 4-6, Section 4.1.2.2, Cap Placement. Since the sediment cap should be placed in
layers, may want to consider placing material from upslope to down slope in lanes
parallel to shore so that material tending to spread laterally downslope will cover the
. down slope areas and not be wasted. If a current exists, you want to place material up
current.
-------
See Section 6.5 (Design Issues-Cap Placement) of the Responsiveness Summary.
A23. Page 4-6, Section 4. 1.2.2, Cap Placement. Snohomish and Duwamish bedload have
See Section 6.5 (Design Issues-Cap Placement) of the Responsiveness Summary.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
"'
See Section 6.5 (Design Issues-Cap Placement) of the Responsiveness Summary.
"*
See Section 6.5 (Design Issues-Cap Placement) of the Responsiveness Summary
" """-«" "r-* »*-« "
A28. Page 4-8, first paragraph. See comment A2 1 above.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
-------
A30. Page 4-13, Section 4.1.6. How vulnerable is the proposed cap to a modest seismic event
in this relatively steep area? A seismic evaluation should be performed for this site. The
proposed cap sands are uniformly graded. Is liquefaction a concern?
See Section 6.2 (Design IssuesGeotechnical) of the Responsiveness Summary.
A31. Page 4-13, Section 4.1.6.1, 3rd Paragraph. It should be noted that the capping sands will
not settle much as they are uniformly graded. Only in situ material will settle.
See Section 6.2 (Design IssuesGeotechnical) of the Responsiveness Summary.
A32. Page 4-13, last paragraph, last sentence: I believe that specifying and/or constraining the
sequence or details of the method of placement may be premature. I suggest this sentence
be removed. See General Comment A2.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A33. Page 4-17, Section 4.2. Do the areas of SQS exceedance (96 acres) and CSL exceedance
(47 acres) take into consideration the slope? If not, volume adjustments may be
necessary to account for the slope. This comment applies to area and volume estimates
throughout the report.
Yes, the areas calculated accounted for slope.
A34. Page 4-19, Section 4.2.2.2. As a critical element of this alternative, disposal of dredged
material should be discussed in this section.
See Section 12 (Disposal/Siting) of the Responsiveness Summary.
A35. Page 4-19, Section 4.2.2.3. Do the volume estimates for capping material reflect the fact
that approximately 5 feet of capping material will be required to end up with a final cap
thickness of 3 feet? This comment applies to volume estimates for capping material
throughout the report.
In the calculation of capping volumes, the additional material that was necessary to provide for
inaccuracies of cap thickness and losses was accounted for. Generally speaking, a 5 foot
equivalent thickness plus losses of 25% was used to determine the potential volume of sand
needed for the deeper (> 100 feet) capping areas.
A36. Page 4-20, last Paragraph. This section describes capping the nearshore area first. This
appears to be in conflict with Section 4.1.2.2, which discusses beginning the capping at
the bottom of the slope and working towards shore.
See Sections 6.2 (Design IssuesGeotechnical) and 6.3 (Design IssuesCap Thickness) of (he
Responsiveness Summary.
-------
A37. Page 4-20 to 4-22. Figures 4-7,4-8, and 4-10 do not clearly elucidate the demarcations
for the capping sequences. The line symbols used (at least in my copy) were
indistinguishable between phase 1 and phase 2.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A38. Page 4-22, third paragraph, last sentence. Add "foot depths" between " 150" and
"offshore".
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A39. Page 4-25, next to last paragraph, second sentence. The mechanics of how the native
sediments would be dredged and stockpiled adjacent to the CAD sites needs more detail.
CAD Site 1 is immediately adjacent to an old Waterways Experiment Station (USCOE)
experimental PCB dump site and the lateral extent of the PCS contamination within the
proposed CAD site would need to be established before the dredging at this location is
accomplished. Also, as noted in appendix A (sheet 2 of 3) barge disposal in 200 feet of
water would likely result in displacement of contaminated material outside the CAD
depression. The mechanics of how the contaminated sediments could be placed in the
CAD depression needs more discussion. Use of geotextile fabric bags, which are capable
of holding up to 400-800 metric meters of dredged material, for disposal would be one
means of potentially minimizing water column impacts and the bottom footprint of the
contaminated material (see EPA Contaminated Sediments News, Number 22 Fall 1998
page 2).
See Section 6.7 (Design IssuesGeneral Issues) of the Responsiveness Summary.
A40. Page 5-12, third paragraph. Given that 28 % of the SQS contaminated sediments and 35%
of the CSL contaminated sediments are on slopes of 18 to 21 %, a "slope stability
analysis" should be conducted as part of the preremedial design for the selected capoine
alternative. rr &
See Section 6.2 (Design IssuesGeotechnical) of the Responsiveness Summary.
A41. Page 5-fZ, Section 5.3.3.5. Discuss seismic failure risk further in this section.
See Section 6.2 (Design IssuesGeotechnical) of the Responsiveness Summary.
A42. Page 5-18, fourth paragraph, last sentence. The frequency of environmental monitoring
of the cap after placement should be greater at the front end out to five years. If the
monitoring confirms cap integrity (evaluating cap stability in high slope areas,
bioturbation, etc.), the monitoring frequency may then be reduced out to 30 ye'ars (e g
years I, 2, 3, 5, 7, 10, 15, 20,25,30).
See Section 11 (Monitoring) of the Responsiveness Summary.
-------
A43. Page 5-20, second paragraph. As noted in comment A39 above, the potential use of
geotextile fabric bags as a method of placing the contaminated sediments in the dredged
depressions at CAD sites 1 and 2 should also be considered/assessed. This method could
significantly reduce water column impacts and also minimize the contaminated sediments
footprint on the bottom.
See Section 6.7 (Design IssuesGeneral Issues) of the Responsiveness Summary.
A44. Page 5-22, fourth paragraph. Monitoring at a CAD site should also consider the use of
the SVPS camera, as noted previously in comment A29 above.
See Section 6.1 (Design IssuesCapping at Depth) and Section 11 (Monitoring) of the
Responsiveness Summary.
A45. Figure 4-12 should also note the location of the WES experimental dump site relative to
the PSDDA site and potential CAD site 1 boundaries.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A46. Appendix C. More discussion of risk and modes of failure needed, particularly risk of
cap loss in seismic event due to steep slopes. Risk assessment should be performed.
See Section 6.2 (Design IssuesGeotechnical) of the Responsiveness Summary.
-------
1
II. Alternatives Analysis and Section 404(b)(l) Evaluation:
General Comments:
A47. There appears to be no purpose for the development of the site-specific criteria in Section
1.2. I believe it would have been effective for EPA to incorporate the criteria as specific
elements to determine compliance with the 9 CERCLA criteria. Although I believe the
site-specific criteria give important information regarding EPA's decision making
process, they are only referred to again in the discussion under the preferred alternative. I
also believe that they could be used effectively within this document, but it would take
some effort to re-write many of the sections. Unless EPA can clearly define the use and
intent of these specific criteria, I recommend that they be removed from the document.
See Section 10 (RAOs /Evaluation Criteria) of the Responsiveness Summary.
A48. I recommend that the dredging alternatives include all of the disposal options (i.e.,
Alternatives 2a, 2b, 2c). This is because the biggest problem with the dredging
alternatives is finding a disposal site that is available, cost effective and environmentally
acceptable. However, the document provides a favorable analysis of, for example,
Alternative 2 without mentioning that there will likely be a major problem finding a
suitable disposal site. This concept needs more development or discussion so that the
reader understands that the dredging alternatives must be evaluated in light of the disposal
options.
See Section 12 (Disposal/Siting) of the Responsiveness Summary.
A49. The document's reference to the CERCLA criteria "Reduction of Toxicity, Mobility, and
Volume" is very confusing. I understand this to be an evaluation of the efficacy of
treatment alternatives. However, the way it is used in this document makes it redundant
with CERCLA criterion 1 (overall protection....). I believe the correct interpretation is
eventually discussed in Section 6 (there are no treatment alternatives at PSR MSU).
Unfortunately, the Section 5 interpretation is not consistent with how EPA discusses the
criterion in Section 4. This should be clarified or corrected throughout the document.
See Section 10 (RAOs /Evaluation Criteria) of the Responsiveness Summary.
Specific Comments:
A50. Page 1-1. Second Paragraph, 1st sentence. "The purpose of this report is to provide EPA,
other interested agencies...." The FS should be by EPA, not directed to EPA. Weston
may have prepared it, but under the direction of EPA, making it EPA's report.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
10
-------
A51. Page 1-2. Last paragraph (criteria bullets). I like the criteria, but EPA may want to
reconsider the 'complete actions within an acceptable time frame (less than 3 years).'
This may unduly restrict the evaluation of potential disposal options. I recommend that
EPA drop the modifier of 'less than 3 years' and let the design details determine what is
an 'acceptable' time frame.
EPA used a target time frame for which the alternatives could be evaluated. For the purpose of
this FS, EPA chose 3 years. An alternative that requires longer than 3 years would not
necessarily be eliminated; however, the additional duration would be factored into the cost and
implementability evaluation of the alternative.
A52. Page 1-3, Section 1.3, 1st paragraph, numerous citations of Weston documents. Are these
EPA documents or Weston documents? If they are Weston documents, what role does
Weston play in the decision making process? Likewise, all of the RETEC citations
should be 'Port of Seattle.' It is my understanding that all of these reports were prepared
for and under the control of a government entity. It, is the government entity that takes
responsibility for the report, and therefore, should be listed as the source of the report.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A53. Page 1-12, Section 1.5.2 (Biota), 1st paragraph, 2nd sentence - 'Some of these species....'
EPA should provide a list or a table of those species of concern and their status (Federal
or State listings).
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A54. Page 2-1. Section 2. EPA should explain how the RAOs and the site-specific criteria
listed in Section 1.2 relate. It appears that the RAOs are the human and environmental
health criteria for the alternatives analysis. Indeed, the first RAO in Section 2.5 says the
same thing as the last site-specific criteria. If that is the case, then I think that both of the
' RAOs should be listed as site-specific criteria.
See Section 10 (RAOs /Evaluation Criteria) of the Responsiveness Summary.
A55. Page 2-ltT 2.4.3.1. Change the last sentence to read 'EPA consults with Department of
Interior on remedial actions to assure appropriate consideration of threatened and
endangered species.'
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A56. Page 2-10. 2.4.3. Location-Specific ARARS. Also include the following as ARARs:
a. Washington State Hydraulic Code (RCW 75.20.100-160). The Hydraulic Code
regulates construction and other work that uses, diverts, obstructs, or changes the
natural flow or bed of fresh or salt waters of the state through the issuance of a
Hydraulic Project Approval (HPA). Although an HPA will not be issued for this
11
-------
1
project, the Hydraulic Code requirements are potentially relevant and appropriate
for dredging and capping activities.
b. Tribal Government to Government Presidential Memorandum of April 29, 1994.
This Order requires consultation with tribal governments on Federal actions that
may affect their lands, interests, and/or resources.
See Section 4 (ARARs) of the Responsiveness Summary.
A57. Page 2-12, Section 2.6, last paragraph. Change 1st sentence reference from 'WESTON'
to 'EPA.'
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A58. Page 3-4, Section 3.2.3. This appears to be an alternative, not a technology. I would be
careful here to not start mixing a technology evaluation with an alternatives analysis. I
recommend moving this entire section to Section 5.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A59. Pages 4-1, Section 4.1.1. This is good detail on dredging but we believe a summary
would work fine in this section, with the details put into an appendix (Sections 4.1.1 to
4.1.1.5). This would make the document a bit more readable by the general public.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A60. Page 4-5, Section 4.1.2.1, second paragraph, last sentence ('Mining/borrowing of marine
sediments....). I recommend this sentence be deleted or contain a warning. Sediment
mining would be highly controversial, involve a extended review process, and require
multiple permits.
See Section 6.4 (Design IssuesCap Source Material) of the Responsiveness Summary.
A61. Page 4-8, Section 4.1.2.3 (Capping Summary), paragraph 2, second sentence. Change
dredge spoils to dredge materials.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A62. Page 4-8, Section 4.1.2.3. I would also include a short discussion on the availability of
dredged materials - that is, the entire amount may not be available at the time of
construction. This is likely to be a major issue in design, so it is worth putting forward
for discussion here.
Proposed navigational dredging projects and the availability of capping material was presented
in Table 4-2 and discussed in Section 4.1.2.1 of the FS.
A63.' Page 5-1, Section 5. I recommend using the language directly from 40 CFR 300 to
present the purpose of the alternative analysis. For example:
12
-------
'This section contains a detailed analysis of viable approaches (as identified in
Section 4) to the remedial action at the PSR MSU. The detailed analysis consists
of an assessment of individual alternatives against each of the nine evaluation
criteria (listed below) and a comparative analysis that focuses upon the relative
performance of each alternative against those criteria.'
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A64. Page 5-1, Section 5. There is no mention regarding the site-specific criteria developed in
Section 1.2. How do they relate to the CERCLA criteria, in what capacity are they
intended to be used, how does this all relate to the RAOs?
See Section 10 (RAOs /Evaluation Criteria) of the Responsiveness Summary.
A65. Page 5-1, Section 5.2 (Analysis Criteria). I recommend changing this to 'Evaluation
Criteria' to be consistent with the 40 CFR 300.
A66. Page 5-1, Section 5.2. I recommend explaining all nine criteria, then note that EPA will
evaluate the last two upon their selection of the preferred alternative. I also recommend a
short paragraph on how EPA considers the nine criteria (threshold, balancing, modifying).
See Section 10 (RAOs /Evaluation Criteria) of the Responsiveness Summary.
A67. Page 5-1, Section 5.2.1. Overall Protection of Human Health and the Environment. I
recommend that this paragraph include some specific standards or concepts that EPA
used to determine a given alternative performance for this site under this criterion. Is
there any standard or level of protection that an alternative must reach to be considered by
EPA to be suitable for consideration at PSR (what is the bottom line?)? Is this where
EPA uses the RAOs to determine overall protection?
See Section 10 (RAOs /Evaluation Criteria) of the Responsiveness Summary.
A68. Page 5-1, Section 5.2.2. (Compliance with ARARs), 2nd paragraph. This paragraph
seems out of context. It is not clear how residual human health risks are associated with
ARARsrThis paragraph maybe more appropriate for Section 5.2.1.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A69. Page 5-1, Section 5.2.3 (Reduction of Toxicity, Mobility or Volume). This criterion, as
written, appears to be redundant with Section 5.2.1. The regulations (40 CFR 300) call
this 'Reduction.... through treatment.' I maybe misunderstanding the terminology, but
the range of alternatives for PSR do not include treatment. Rather, they are removal or
isolation technologies. There should be some connection made with the actual Superfund
criterion in the regulations.
See Section 10 (RAOs /Evaluation Criteria) of the Responsiveness Summary.
13
-------
1
fnle CERCLAl 7' "?* ^ " t0 h°W EPA aCtUaHy USCS ** cost -a
V; ^ , A , f IS1°n makmg prOC6SS- A "COSt eff^veness" discussion would
be helpful here to clarify how each alternative "ranks" relative to others in terms
C ne
neSS< f T7l6' EPA ^ fmd Aat a 8iven «*a~ Prides only
increased level of protection at an order of magnitude greater cost than another
a e d t^ deTine ^ ^ bCnefitS aCCmS " r°P^c
hllnT H T 7^ ^ excePtionally h*r costs. This type of discussion would
help the reader (and decision maker) to understand the tradeoffs
See Section 7 (Cost Effectiveness) of the Responsiveness Summary.
A71. Page 5-5, Section 5.3.2 (Alternative 2). Alternative 2 cannot stand alone in evaluation
because a critical factor for this alternative is the ability to dispose of 372 000 ctblcyard
of contaminated matenais. For example, I am not sure dredging with neaishorrd
****** bK6CaUSe °f SUbStantfaI -d --ersib'efmpac "to aqultic
H
a, 2b, and 2c) and their evaluation under the criteria.
See Sec/zow 12 (Disposal/Siting) of the Responsiveness Summary.
A72. Page 5-5 Section 5.3.2.1. This is where is would be helpfiil to the reader if EPA
discussed the merits overall protection' of Alternative 2 compared to some
isk and the hazard index? Does Alternative
See Section 10 (RAOs /Evaluation Criteria) of the Responsiveness Summary.
A73. Page 5.5, Section 5.3.2.2. Recommend that this section be re-written as follows:
^=£^^^^
evaluation upon determination of the preferred alternative'.
ARARs would include:
a. Substantive compliance with Washington State Sediment Management Standards.
b. Substantive compliance with Washington State Water Quality Standards both
during and post project construction (Section 401 of the Clean Water Act)
dc^^^
14
-------
c. Substantive compliance with Section 404 of the Clean Water Act and Section 10
of the Rivers and Harbors Act.
d. Substantive compliance with Washington State Hydraulic Code.
e. Substantive compliance with Washington State Shorelines Management Act (and
Coastal Zone Management Act).
f. Coordination with National Marine Fisheries Service and the U.S. Fish and
Wildlife Service consistent with Section 7 of the Endangered Species Act.
g. Consultation with the Muckleshoot Indian Tribe and the Suquamish Indian Tribe.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A74. Page 5-6, Section 5.3.2.3. See Comment A69.
See Section JO (RAOs /Evaluation Criteria) of the Responsiveness Summary.
A75. Page 5-9, Section 5.3.3.1. See Comment A72. What is the significance of the risk
reduction estimates? Do both 3a and 3b meet this threshold criterion?
See Section 3 (Risk) and Section 10 (RAOs / Evaluation Criteria) of the Responsiveness
Summary.
A76. Page 5-10, Section 5.3.3.2. See Comment A73. It is inappropriate at this level of review
to determine ARAR compliance. However, it is appropriate to point out where there may
be difficulty achieving compliance (for example, see Footnote 1).
See Section 14 (Editorial Comments) of the Responsiveness Summary.
All. Page 5-10, Section 5.3.3.3. See Comment A69.
See Section 10 (RAOs /Evaluation Criteria) of the Responsiveness Summary.
A78. Page 5-lT, Section 5.3.3.7 (Cost). See Comment A70. This would be a good place to
discuss the relative merits (if there are any) of the substantially higher costs of alternative
3a. In other words, is alternative 3a a cost-effective alternative?
See Section 7 (Cost Effectiveness) of the Responsiveness Summary.
A79. Page 5-14, Section 5.3.4 (Alternative 4). As with Alternative 2, Alternatives 4a and 4b
have a significant disposal problem that should be evaluated as a complete alternative
(see Comment A71).
See Section 12 (Disposal/Siting) of the Responsiveness Summary.
15
-------
A8°-
See Section 10 (RAOs /Evasion Criteria) of, he Responsiveness Summary.
s
be difficu,* aching ^f?* ""' """ """
See Section 14 (Editorial Catena) of, he Responsiveness S»mmary.
A82. Page 5-15, Section 5.3.4.3. See Comment A69.
See Section W(RAOs /Evolution Criteria) oftke Responsiveness Sun.n.ary.
A83. Page 5-18, Section 5.3.4.7. See Comment A70.
See Section 7 (Cost Effectiveness) of the Responsiveness Summary.
aone
review of these alternatives, I belie^t of ^.e i^?? " f8 " page by pa8e
alternatives are appiicable ,o lie sections C°mme'"S f°r 'he previous
&. &c«on 14 (Editorial Comments) of the Responsiveness Summary.
A85-
explanation how this process was used for r dedston
/OM /O (RAOs , Evasion Criteria) of, He Responsiveness Summary.
A86. Page 5-30, Section 5.5. 1. Do aU of the Alternatives mee, this threshold criterion?
See Section WfRAOs /Evaluation Criteria) of, he Responsiveness Summary.
"'
See Section 10 (RAOs /Evaluation Criteria) of the Responsiveness Summary.
~
16
-------
See Section 10 (RAOs / Evaluation Criteria) of the Responsiveness Summary.
A89. Page 5-33, Section 5.5.7 (Cost). Are all of these costs considered cost effective
(acceptable) for this project purpose (see Comment A70)?
See Section 7 (Cost Effectiveness) of the Responsiveness Summary.
A90. Page 5-34, Section 5.6.2. This is not what is said in the ranking analysis, which stated
that all alternatives complied with ARARs. I agree with this statement and would add
that the nearshore and deeper CAD alternatives are likely to have an extremely hard time
passing the various ESA and 404 criteria and coming into compliance with both sets of
regulations.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
A91. Page 5-34, Section 5.6.3. See comment for Page 5-31, Section 5.5.3.
See Section 10 (RAOs / Evaluation Criteria) of the Responsiveness Summary.
A92. Section 5-37, Section 5.7. How do the numerical rankings relate to the criterion? How
do they relate to the RAOs? Are all of the alternatives equally viable? Do any of the
alternatives fail to meet the threshold Criteria (the nearshore/CAD disposal alternatives
are somewhat up in the air for ARAR compliance)? I would add some discussion
regarding what EPA thinks about the results of the numerical rankings and their
interpretation of compliance with the Criteria. This would make a better introduction to
the selection of the preferred alternative.
See Section 10 (RAOs /Evaluation Criteria) of the Responsiveness Summary.
A93. Page 6-2, Section 6.3. I recommend that EPA explain the performance criteria and their
purpose at this stage of the document. What would have happened if the preferred
alternative failed any of the performance criteria? They seem unnecessary and redundant
at this stage. My recommendation is to incorporate the performance criteria into the
Superfund criteria for the alternatives analysis. They could be considered site specific
considerations for the evaluation of the threshold and balancing criteria. A suggested
format is as follows:
a. The project must provide for the overall protection of human health and the
environment.
1) The project must result in a human health excess cancer risk of less than I
in 10,000 and a non-cancerous hazard index of less than 1.0.
2) The project must prevent marine organisms from contacting sediments that
exceed the SMS chemical criteria to reduce potential unacceptable impacts
to the benthic community.
17
-------
1
b. Compliance with ARARs
3) more?
c. Reduction of toxicity, mobility or volume through treatment.
1) N/A (no treatment)
d- Short term effectiveness
envtal
2) minimize risks to worker safety during implementation
3) minimize impacts to current water dependent industries
4) minimize impacts to tribal, recreational, and/or commercial fisheries.
5) maintain the physical integrity of in-water constructed features
e. Long-term effectiveness
1) The project must provide a minimum design life of 30 years ffor
engineered components)
2) The project must maintain geotechnical stability of shoreline
f. Impleraentability
1 ) The project must be constructive at this site.
2) The project must be technically feasible for this site.
3) The project actions must be completed within an acceptable time-frame..
g. Cost
1 ) must provide tangible benefits for money spent.
See Section 10 (RAOs / Evaluation Criteria) of the Responsiveness Summary.
18
-------
U.S. Army Corps of Engineers Comments
Proposed Plan (April 1999)
Pacific Sound Resources Superfund Site
I. Engineering Considerations for RD/RA:
General Comments:
A94. The proximity of the Federal project in the Duwamish River makes Corps' maintenance
dredging material the most logical source of capping material. If cap placement methods
utilized readily available dredging equipment, (similar to the placement methods used in
Eagle Harbor), only minor modifications to routine maintenance dredging contracts
would be required, and capping cost would be minimal. The PSR Superfund Project
would have to pick up only the incremental increase in the disposal cost over open water
disposal at the Elliott Bay PSDDA site. For this reason, every effort should be made to
adjust the "estimated time to cleanup" to the Duwamish maintenance dredging volumes
and schedule.
See Section 6.4 (Design IssuesCap Source Material) of the Responsiveness Summary.
A95. The combination of readily available maintenance dredged material and the steep bottom
slopes of the PSR site may offer a particularly attractive option for construction of the
Alternative 3 cap. Hydraulic placement methods could be used to gently place a layer of
dredged material in a relatively shallow portion of the area to be capped. This area could
then serve as a disposal site within which the standard bottom dump barge disposal
method was allowed. Material placed by this method would flow down the steep bottom
slope and cover the deeper contaminated sediments. Since the haul distance to the PSR
site and the existing PSDDA site are essentially the same, the construction cost for a
significant portion of the PSR capping project could conceivably be eliminated.
See Section 6.5 (Design IssuesCap Placement) of the Responsiveness Summary.
A96. Maintenance dredged material from the Federal channel in the Snohomish River is an
alternative source of capping material, but at an increased cost. Obtaining capping
material from a marine borrow source is so unlikely that it should be dismissed outright
due to adverse environmental impacts. The use of an upland source for capping material
would increase capping costs by more than an order of magnitude and does not make
sense from an economic standpoint.
See Section 6.4 (Design IssuesCap Source Material) of the Responsiveness Summary.
A97. See FS General Comment A4 above regarding discussion of natural recovery processes as
they might attenuate sediments in SQS contaminated areas.
See Section 9 (Natural Recovery) of the Responsiveness Summary.
19
-------
Specific Comments:
A98. Pg. 9, Alternative 2 and Alternatives. Can the dredging and capping costs be broken out
as separate items?
The requested information is provided below:
Alternative 2:
Dredging costs are $3,248,000
Cappings costs are $1,413,000
Alternative 3
Dredging costs are $585,000
Capping costs are $4,261,000
A99. Page 2, fourth paragraph. A slope stability analysis should be accomplished during pre-
remedial design to assess the stability of capping on slopes ranging from 18 to 21%.
See Section 6.2 (Design IssuesGeotechnical) of the Responsiveness Summary.
20
-------
WASHINGTON STATE DEPARTMENT OF
Natural Resources
May 14, 1999
Ms. Sally Thomas, Project Manager
Office of Environmental Cleanup
US EPA Region 10
1200 Sixth Avenue, MS ECL- 111
Seattle, WA 98101
Subject: Comments on the Pacific Sound Resources Superfund Site Proposed Plan, April 1999
and the Draft Feasibility Study, Pacific Sound Resources, Marine Sediments Unit,
Seattle, Washington, November 1998
Dear Ms. Thomas:
Enclosed please find comments regarding the aforementioned documents. The comments have been
prepared on behalf of the Washington State Department of Natural Resources (DNR) and are based
on summary reviews of the documents. DNR review and comments concentrate on the marine
sediment unit at the site. The information discussed herein represents DNR's comments on the
specific documents noted and should not necessarily be viewed as DNR's final determinations for
this site.
As land manager for the state-owned aquatic lands at the site, DNR is concerned about cleanup,
appropriate land use, and risk and responsibility management. As natural resource trustee, DNR
seeks to protect, restore and sustain natural resources. In general, DNR finds the analysis for the
PSR site inadequate to fully evaluate a preferred alternative for the marine sediment unit. DNR
therefore believes that additional analysis is necessary before limiting options for the site. The
following discussion identifies a number of issues that DNR believes require additional
consideration.
Dla. Baywide Context
Throughout much of the proceeding discussion, a number of issues will be discussed that
relate to the concept of scale in decision-making. As DNR has stated during review of
Feasibility Study (FS) technical memoranda, storage of contaminated sediment on state-
owned aquatic lands must be based on a baywide planning effort that shows this use, to be
in the best interest of the resources and the public. Such a context will facilitate decisions
that help return resource function and ensure resource protection and sustainability for the
long-term benefit of the resources and the public. Evaluation points associated with these
1111 WASHINGTON ST SE PO BOX 47000 OLYMPIA. WA 98504-7000
FAX. (360)902-1775 7TY. (360)902-1125 TEL: (360)902-1000
-------
Ms. Sally Thomas
Page 2
May 14, 1999
decisions include: 1. Consistency with the department's state land use plans; 2. A clear net
gain in habitat area and Function; 3. Protection and creation of critical habitats for listed or
candidate threatened or endangered species; 4. Efficient use of state-owned aquatic land
material for beneficial uses as defined in the Puget Sound Dredged Disposal Analysis
guidelines; 5. Disposal alternatives that prepare for rebuilding large blocks of habitat areas;
6. Disposal alternatives that provide for acquisition and/or development of strategic habitat
areas; 7. Avoidance and minimization of impacts and compensatory mitigation measures;
and 8. The best rate of return on the investment of state natural resources.
It is EPA 's understanding, based on discussions with DNR staff, that the baywide context being
referred to would require preparation of some type of management plan for Elliott Bay, Currently
this does not exist and delay of the cleanup to accommodate development and adoption of such a
plan would be inappropriate.
Dlb. In addition, from a cleanup perspective, site-specific decisions that do not adequately
consider cleanup issues at adjoining or area-wide sites may result in options being precluded
for a number of these sites and potential efficiencies being lost.
See Section 12 (Disposal/Siting) of the Responsiveness Summary.
Die. DNR would like to encourage EPA to pursue decision-making from a baywide scale. This
approach is being utilized at other cleanup sites in Puget Sound and is consistent with a
number of initiatives, including EPA's Aquatic Ecosystem Protection, Achieving
Environmental Results in EPA Region 10, three year action plan.
Please see response to Dla.
D2. Protectiveness
DNR does not believe that capping to cleanup screening levels is protective of natural
resources. It also is inconsistent with prioritization of restoration at this site. The Proposed
Plan states that EPA has considered in its decision the recent information provided by the
National Oceanographic and Atmospheric Administration demonstrating adverse effects to
bottom fish at polycyclic aromatic hydrocarbons (PAH) concentrations much lower than
current regulatory levels of concern. However, it is unclear how the analysis summarized
in the Proposed Plan includes consideration of this new information. Also, although the draft
is preliminary, it is important to note that the proposed changes to a number of the chemical
criteria for PAHs in the Washington State Sediment Management Standards reflect adverse
effects at much lower concentrations.
See Section 13 (Restoration Goals) of the Responsiveness Summary.
-------
Ms. Sally Thomas
PageS
May 14, 1999
D3. Site Identification and Description
D3a. DNR would like to request that the products being offered for public review and comment
clearly identify the public-aquatic lands within the site boundaries. It is critical for the public
to understand that the decisions being made at the site have specific implications for the
citizens of this state.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
D3b. In a related matter, DNR would like to suggest that in the FS, the applicable or relevant and
appropriate requirements discussion regarding the State Aquatic Lands Management Laws
and Public Trust Doctrine be revised because both are inaccurately summarized. The statutes
constituting the Aquatic Lands Acts are RCW 79.90 through 79.96. Of particular importance
are the statutes on Harbor Areas (RCW 79.92) and Bedlands (RCW 79.95). These, as well
as Aquatic Land Management, Chapter 332-30 WAC, should be appropriately summarized.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
D3c. The Public Trust Doctrine should be summarized separately from the State Aquatic Lands
Act and related WACs. The clear purpose of the public trust doctrine as held by the US
Supreme Court is to preserve and continuously assure the public's ability to fully use and
enjoy public trust lands, waters, and resources for certain public uses (Slade et. al., Putting
the Public Trust Doctrine to Work, Second Edition, June 1997. Page 3).
See Section 4 (ARARs) of the Responsiveness Summary.
D4. Land Use
D4a. A numbsF-of land use issues need additional consideration. Many are associated with the fact
that the marine sediment unit is within a state Harbor Area that is reserved to facilitate land-
water transfer of goods. The Harbor Area will be significantly and permanently altered under
the preferred alternative, and there is no contingency for future land use decisions beyond the
statement in the Proposed Plan that the State and/or the Port may want to alter the depth at
some future time which EPA believes can be accommodated without compromise to the
proposed remedy. It is unclear what analysis was completed by EPA to reach such a
conclusion, and it appears as though the lost navigational capacity in the state Harbor Area
may represent a permanent loss of water dependent commerce potential. In analyzing the
appropriateness of fill in a harbor area, the facilitation of land-water transfer must be
considered. For example, from a harbor area land use perspective, a fill for 62 acres of
container storage is less problematic than a 62 acre fill for contaminant containment or
habitat restoration.
-------
Ms. Sally Thomas
Page 4
May 14, 1999
The Port of Seattle and DNR may need to develop recommendations to the Harbor Line
Commission on the reconfiguration of the Harbor Area. All such recommendations must be
consistent with: 1. maintaining or enhancing the type and amount of harbor area needed to
meet long-term needs of water dependent commerce; 2. maintaining adequate space for
navigation beyond the outer harbor line; and 3. any other relevant harbor area studies,
regulations, or policies.
Please see Section 2 (Potential Impacts to Land Use) of the Responsiveness Summary.
D4b. Also, the institutional controls mentioned in the documents are not sufficiently defined to
evaluate the impacts of a navigational encumbrance. It is unclear if EPA is proposing a no-
anchor zone/regulated navigation area that will prohibit cap disturbance from activities such
as anchoring, prop wash, or laying cable. Any no anchor zone/regulated navigation area will
have additional navigational impacts throughout the Harbor Area. And, finally, it is not clear
if EPA has made provisions for vessel loss of control and emergency anchoring adjacent to
the federal navigation channel.
Please see Section 2 (Potential Impacts to Land Use) of the Responsiveness Summary.
D4c. In a related matter, given that this is a federally funded and federally approved project, it is
unclear if a Section 106, National Historic Preservation Act evaluation has been or needs to
be completed at the site.
See Section 4 (ARARs) of the Responsiveness Summary.
D5. Source Control
DNR believes that additional clarification of source control information is necessary, both
for on-ske and off-site sources.
D5a. On-site
DNR is concerned about the potential for recontamination in the intermediate groundwater
discharge zone and generally does not support cleanup without source control first being
completely addressed. It is also unclear if all other mechanisms for transport from the upland
portion of the site to the offshore have been controlled. For example, the FS states that the
Longfellow Creek overflow potentially receives groundwater from the site.
See Section 8 (Source Control and Potential for Recontamination) of the Responsiveness
Summary.
-------
Ms. Sally Thomas
PageS
May 14, 1999
D5b. Off-Site
There is preliminary discussion of other potential off-site sources provided in the documents.
However, it is unclear if a thorough analysis has been completed to evaluate the potential for
these off-site sources to impact the site and the proposed remedy. For example, although it
is noted that the stormwater discharge from the Longfellow Creek overflow is permitted,
information regarding the potential for the discharge to impact the cap is not provided.
Transport of material from the Lockheed site and sources associated with operations at
Crowley Marine Services are also uncertain.
See Section 8 (Source Control and Potential for Recontamination) of the Responsiveness
Summary.
D5c. Sediment Total Maximum Daily Load (TMDL)
It is unclear if the proposed cleanup constitutes an EPA-approved sediment TMDL. However,
the apparent lack of clarity in source analysis, as well as a number of other factors, seems to
suggest it does not.
The Proposed Plan and the Record of Decision do not constitute a TMDL for Elliott Bay.
D6. Preliminary Cap Design
DNR is concerned about the placement and long-term stability of a cap because of the
significant slopes at the site, the characteristics of the contaminated sediments, and the
uneven distribution of the contaminated materials (i.e., the mounds of contaminated
materials). EPA recognizes that it has similar concerns but, through consultation with the
US Army Corps of Engineers, has determined that these issues can be adequately addressed
during the design and placement of the cap. This discussion needs to be significantly
substantiated. Without substantiation, it is unclear if the proposed remedy meets the
selection criteria.
DNR is also concerned about the proposed depth of the cap. The cap needs to effectively
isolate and provide unimpacted sediment of appropriate characteristics to achieve sustainable
biological function. Finally, the analysis of potential disturbances to the cap, especially in
the vicinity of Crowley Marine Services and in other nearshore areas, seems too cursory in
both documents.
See Sections 6.2 (Design IssuesGeotechnical) and 6.3 (Design IssuesCap Thickness) of the
Responsiveness Summary.
-------
Ms. Sally Thomas
Page 6
May 14, 1999
D7.
D7a.
*:/, - *.- «**» «»*
(capping, nearshore contaem facil de water LTT contarai"a»< Ca
and that long-term effectiveness fa aTure7bvT f "? aqUat'C disposal> * 30 1*
design life. measured by the facilrty performance during this 30
D7b-
in this appendix are
ofO.l g. This level of ground moti
years using fte resuto ff Ae U S
for areas encompassing the Port
buildings be desired to a 10%Tn 50
Washington State Department of ^
municipal solid waste SfflU are
of Ecology regulation" o
30
8r°Xmd motion ^PP1"*
! P^n"y reiluires *at "e *
; J design level is "^ ^ «*
h* "pT. gh"ay Constn"='io°- AU
" " "" ^^ StaK
to
much longer.
a 30 year time peri
more realistic, project lifetime
motions.
^
°[ ^ e fac""'es' «*<<* «H undoubtedly be
" Pef »« ( d over
?* P'^ A ta*r' **
leveb of seismic ground
See Section 6.6 (Design ^Ues-Life/Duralion) ofthe g^^^ ^^
D7c. It i '
considered. . ..^ .UMUwiug J5 a paniai list c
been adequately addressed in the draft FS
isoiation
, earth1uake
*" '°
motions are
lhat ha- »
-------
Ms. Sally Thomas
Page?
May 14, 1999
1) Section 4.1.7.2 suggests that dredging to a 3:1 slope (slope angle of 18°) will remain
stable. On page 4-5, the angle of repose of sand used in capping is estimated at 20°,
and is the maximum slope on which capping can occur. Consequently, capping on
any slope dredged to 3:1 will be marginally stable and would undoubtedly be
unstable under reasonable seismic loading. The likelihood of instability will be
greatly increased if the capping material is liquefiable and can fail as a flow slide.
Liquefaction-induced flow slides of capping material placed on shallower slopes has
also not been evaluated for realistic earthquake ground motions. Consequently, long-
term performance of this contaminant isolation action is uncertain and may in fact not
be feasible for certain areas of the marine sediment unit.
2) Stability analyses presented in Appendix C for the nearshore containment berm
evaluate conditions for a very low level of earthquake ground motion. The
evaluations presented in this appendix ignore soil liquefaction and its potential
impact on the foundation conditions of the containment berm. Likewise, the
potential for a global slope instability (one that encompasses the entire delta slope)
is not considered in Appendix C. Consequently, long-term performance of this
contaminant isolation action is uncertain, and may in fact not be a feasible option.
See Section 6.2 (Design IssuesGeotechnical) of the Responsiveness Summary.
Did. EPA provides a preferred alternative for cleanup of the marine sediment unit that is based
in part on ranking of the long-term effectiveness of the various mitigation options. The
present FS fails to adequately evaluate the potential impact of realistic earthquake ground
motion on long-term performance of the various options. As a result, EPA is not certain that
the preferred alternative can be implemented. This uncertainty is addressed in section 4.1.6
with the closing statement:
"If an alternative is selected that includes capping or a nearshore disposal facility, the
supporting geotechnical analysis necessary to implement this approach would be
performed during remedial design."
This statement makes the presumption that the supporting geotechnical analysis will
demonstrate the feasibility of implementation of the chosen alternatives. The FS should
outline the actions that would be taken if the supporting geotechnical analysis demonstrates
that the chosen alternative is not feasible.
-------
Ms. Sally Thomas
Page8
May 14, 1999
If during the design process, the proposed alternative is shown to be infeasible, EPA will evaluate
other alternatives.
D8. Long-term Evaluation
As discussed in the preceding section in relation to stability/earthquake issues, the evaluation
of long-term implications associated with the proposed remedy is inadequate The design
life of 30 years does not represent the life of the containment facility on state-owned aquatic
lands, and it does not represent a timeframe for long-term trust management at the site For
these reasons, the analysis provided does not adequately address long-term risks and
responsibilities that will fall to the citizens of the State after 30 years. There is also
uncertainty regarding the long-term risks and responsibility for the groundwater
contamination and its potential impact to the offshore, as well as for assuring the long-term
viability of the slurry wall. The completed remedial actions on the uplands and the proposed
remedy for the marine sediment unit are not permanent solutions, and limiting the analysis
to a 30-year timeframe does not provide an adequate basis for decision-making At a
minimum, a discussion should be provided regarding projected contaminant levels at the end
of the design life.
See Section 6.6 (Design IssuesLife/Duration) of the Responsiveness Summary.
D9. Cost Analysis
DNR appreciates the inclusion in the Proposed Plan of valuation issues associated with the
use of state-owned aquatic lands and will be sending within the next several weeks updated
information regarding the valuation of state-owned aquatic lands. However, the cost
analysis provided appears to exclude a number of cost considerations in addition to the
recognized valuation issues. For example, potential restoration and mitigation costs are not
mcludedr Also, there appears to be uncertainty in some of the cost estimates used in the
analysis. For example, the cost of $110 per cubic yard for disposal at an existing upland
landfill does not appear to be consistent with the cost range provided in the Draft Puget
Sound Confined Disposal Site Study, Programmatic Environmental Impact Statement
February 1999. And, finally, the decision process for eliminating potential remedies based
primarily on cost-effectiveness needs to be better defined throughout the documents (i.e., the
factors evaluated in determining cost-effectiveness).
Please see responses to Comments Trustees-3. Army Corps of Engineers-13, and
Section 7Cost Effectiveness.
-------
Ms. Sally Thomas
Page 9
May 14, 1999
DIOa. Other Initiatives
DNR would like to encourage EPA to evaluate its analysis of a preferred alternative in the
context of other applicable initiatives such as EPA's Aquatic Ecosystem Protection,
Achieving Environmental Results in EPA Region 10 and EPA's Contaminated Sediment
Management Strategy. The principals and goals provided in these documents should be used
in evaluating approaches for this site (e.g., watershed context, reduction in volume of
existing contaminated sediment, and development of scientifically sound sediment
management tools).
The approach used to define the problem and select a remedy for the PSR MSU is in keeping with
EPA 's Contaminated Sediment Management Strategy. Scientific methodologies developed under
the Puget Sound Estuaries Program and updated as part of the SMS and the DMMP were employed
on this project. Extensive coordination with and review by regulatory and Trustee agencies further
refined the decision-making process implemented at this site.
DIOb. Also, because of the number of difficult technical issues at this site, DNR would like to
encourage EPA to continue to evaluate innovative technologies as potential components of
a solution for the marine sediment unit (e.g., it has been suggested that geotextile tubes be
used as containment for the contaminated sediment and that the filled tubes be used as
stabilizing devices in the offshore).
See Sections 6.2 (Design IssuesGeotechnical) and 6.3 (Design IssuesCap Thickness) of the
Responsiveness Summary.
DNR looks forward to continuing discussions regarding these issues and would like to suggest that
a meeting be scheduled. Please contact me at 360-902-1068 or at tamara.allen@wadnr.gov with
information regarding the possibility of a meeting or with any questions you might have. Thank you
for the opporturnTy to provide input.
Sincerely,
Tamara Allen, Environmental Specialist
Aquatic Resources Division
PO Box 47027
Olympia, WA 98504-7027
c: Paul Silver, Deputy Supervisor, DNR
Craig Partridge, DNR
-------
1
Ms. Sally Thomas
Page 10
May 14, 1999
Maria Victoria Peeler, Division Manager, DNR Aquatics
Mike Palko, ADM, DNR Aquatics
Tim Goodman, DNR Aquatics
Carol Lee Roalkvam, DNR Aquatics
Don Olmsted, DNR Aquatics
Bill Graeber, DNR Aquatics
Cathy Carruthers, DNR Aquatics
Steve Palmer, DNR Geology
Christa Thompson, AGO
Michelle Wilcox, Ecology, SMU
Pete Adolphson, Ecology, TCP NWRO
-------
STATE OF WASHINGTON
DEPARTMENT OF ECOLOGY
Northwest Regional Office, 3190 - 160th Ave S.E. # BeUevue, Washington 98008-5452 # (425) 649-7000
May 14, 1999
Ms. Sally Thomas
EPA Region 10 - Superfund
1200 Sixth Avenue ECL- 111
Seattle, WA 98101
RE: Proposed Plan for Cleanup of the Pacific Sound Resources (PSR) Superfund Site
(EPA dated April 1999)
Dear Sally:
The Department of Ecology received the above document on April 15, 1999, and have
completed our .review. The attached comments mostly focus on the Draft Feasibility
Study for the Offshore Unit, since agency comments were to be formally submitted
during the comment period for the Proposed Plan. The comments were prepared by
Glynis Carrosino, Ecology Project Manager, and Peter Adolphson, Ecology Sediment
Cleanup Specialist.
The Proposed Plan identifies the Preferred Cleanup Alternative for addressing soil,
groundwater and marine sediments at the PSR site. The focus of this Proposal is on the
contaminated sediments associated with the marine sediment unit, as EPA believes that
the risks due to soil contamination have been controlled through early actions. The
Preferred Alternative presented in this Plan proposes leaving contamination in place and
meeting environmental and human health protection goals through controlled
containment (capping in place). At this point in time, Ecology is supportive of the
proposed remedy, though we do have critical opinions on the Feasibility Study and have
identified issues we expect to be addressed during design, prior to cap placement.
Ecology would expect other cleanup options to be considered, should predesign not
support the cap alternative and Ecology's concerns (re attached comments).
EPA, in consultation with the Washington State Department of Ecology, will select a
final remedy for the site after reviewing and considering all information submitted during
the 30-day public comment period on this Proposed Plan. We look forward to upcoming
project discussions.
-------
Ms. Sally Thomas
May 14, 1999
Page 2
If you should have any questions regarding these comments, please contact me at 425-
649-7263, or Peter Adolphson at 425-649-7257.
Sincerely,
Glynis A. Carrosino, Project Manager
Toxics Cleanup Program
cc: Peter Adolphson, Ecology NWRO
Steve Alexander, Ecology NWRO
Kathy Gerla, Office of the Attorney General
-------
1
May 14, 1999
Ecology Comments re Pacific Sound Resources Draft FS/Proposed Cleanup Plan:
Glynis Carrosino (WA Dept. of Ecology - NWRO)
Peter Adolphson (WA Dept. of Ecology - NWRO)
General Comments:
E1. The Preferred Alternative selected from the Draft Feasibility Study and presented in the
Proposed Plan proposes leaving contamination in place and meeting environmental and
human health protection goals through controlled containment (capping in place). The
preference for capping contaminated marine sediments at PSR is primarily based on
difficulties associated with other alternatives. Also, reflective of the specific issues
associated with this site was that the human health risk goal also had to account for
background levels already present in Elliott Bay.
E1 a. Ecology continues to have concerns about placement of a cap where the slope has been
documented as being very steep (up to 21 percent). A cap placed on an area with a steep
slope has the potential for slump and containment failure. The sediments in this unit are
also soft and highly contaminated, and placement of capping material onto the soft
sediment has the potential to resuspend the contaminated sediment into the water column.
See Section 6.2 (Design IssuesGeotechnical) of the Responsiveness Summary.
Elb. Depth is also an issue (the deep area has been documented to be greater than 200 feet) to
ensure the minimum 3 foot capping thickness can be maintained. These issues must be
addressed during design, prior to cap placement.
See Section 6.1 (Design IssuesCapping at Depth) of the Responsiveness Summary.
E2. There are significant misinterpretations throughout the Draft Feasibility Study Report
with respect to the risk calculations. Section 4 contains values which are clearly above the
NCP risk value l.OE-4 (e.g. 1.3E-4). This interpretive error is presented consistently
throughOTtthe report and will have a significant impact upon selection of preferred
alternatives. Similar misinterpretation also exists with respect to these values (e.g.
Section 5.3.4.1 designates 5.7E-05 as equivalent to 1: 100,000. The value 5.7E-05 is
equivalent to 1: 17,544. See also 5.5.3.1 etc. The values calculated above and those
cited in the proposed plan exceed Ecology's acceptable risk values for significant human
health effects. There appears to be confusion with respect to interpretation of risk values
throughout the report as well as the proposed plan.
See Section 3 (Risk) of the Responsiveness Summary.
E3. Comments submitted to EPA by Ecology, 11/3/97, (Teresa Michelsen, Laura Weiss)
concerning cleanup areas also referenced Ecology ARARs: "Since this site will require
state concurrence, please recognize and discuss the MTCA risk ranges that will need to be
-------
adhered to ^IXIO"4 for individual chemical and <1X10'5 for overall)." "Given the
±Temen for State concurrence at this site, and for Superfund to meet State ARARs it
wou d s^em appropriate for the risk assessment results to be reviewed in light of MTCA
Tcceptable risk ranges, as well as EPA's risk management range. It is inexplicable to
Ecote why we have'to keep making this basic request atsite ^^^ °f
quartile approach is inappropriate for areas exceeding ARARs (CSLs or 1x10 nsk),
any such area must be actively remediated."
See Section 4 (ARARs) of the Responsiveness Summary.
Specific Comments:
E4 231- Reference to data and methods for Ecological risk and Human health risk including
' theElliot Bay Background cancer risk level section should be cited.
The risk assessment approach was detailed in the Section 4.5.4 of the RI work plan (WESTON
^996) DaT^e presented and evaluated (with a further discussion of guidance used) in
Appendix K of the RI report (WESTON 1998)
F5 oe 3-5- Please include the citations for the conclusion that in areas that are thin-layer
capped bicSrbation will result in a reduction of the sediment contaminant concentrations
by 50%.
h d an assumption that if thin layer clean cap material was placed at a
IMS estimate LA- /5 m) complete mixing within the bioturbation zone
iESSH^
than the original sediment contaminant concentrations.
E6. For purposes of cap placement on slopes exceeding 15%, how is "base" of slope defined?
j tt,aJi,tnrtri> -{fa base Of fa slope did not include the distance where a slope runs out to avoia
obtaining less of a slope than really exists.
P7* 4123- Please cite the data (e.g. in situ pre-tests) which support the conclusion that a
3 foot l'ayer^f s'lty sld will clinically and physically confine sediment, exceeding the
or greater slope?
be determined in design.
-------
E7b. Seismic considerations remain largely unaddressed with respect to the proposed plan,
particularly in areas with slopes greater than 15%. And these areas constitute
approximately 35% of the CSL area and significant SQS contaminated areas as well.
See Section 6.2 (Design IssuesGeotechnical) of the Responsiveness Summary.
E8. pg. 4-8: The proposed plan requires capping of CSL areas only. Due to depth, slope and
fine-grained unconsolidated nature of these contaminated sediments, a significant
amount of sediment resuspension and migration can be expected resulting in potential
expansion of the CSL areas currently categorized as SQS. How will potentially
recontaminated areas be addressed in this scenario?
See Section 11 (Monitoring) of the Responsiveness Summary.
E9. 4.3.2: The text states that one criteria for sijing a CND was that it could not be located in
habitat restoration or enhancement areas. It appears that this criteria automatically
precludes combined CND habitat enhancement areas, however one usage does not
necessarily preclude the other. Siting criteria may need modification.
See Section 12 (Disposal/Siting) of the Responsiveness Summary.
E10. 5.2.7: Cost: It does not appear that costs for the implementation of the preferred
alternative of leaving contaminated sediment on state lands and implementing capping
were included in cost estimates. Does EPA have any current information from DNR?
There is currently no agreement with respect to costs associated with capping of state owned
aquatic lands.
Ell. Has a model been performed which predicts recovery of the areas currently above SQS to
levels not exceeding the SQS if the CSL areas are capped?
See Section 9 (Natural Recovery) of the Responsiveness Summary.
E12. Pg. 6.3: The Human Health risk presented in the text of 6.6E-05 does not meet Ecology's
"no significant human health risk" criteria of 1 .OE-05 to 1 .OE-06.
See Section 3 (Risk) of the Responsiveness Summary.
El3. In areas which remain uncapped, will the biologically active zone fall below SQS within
the specified 10 year recovery period?
See Section 9 (Natural Recovery) of the Responsiveness Summary.
E14. pg. 1-15: Ecology has discussed with EPA contingency plans and actions to respond and
meet original cleanup goals should recontamination occur at the site.
-------
yes. EPA will continue to coordinate with Ecology throughout design and implementation of the
remedy. In addition, Ecology will be the key reviewer of the long-term operations and
maintenance plan, where the contingency planning process will be defined.
E15. pg. 2-2 section 2.2.1.1: second paragraph Insert as second sentence "However, the SMS
does have a narrative standard for human health of no significant health risk to humans."
See Section 14 (Editorial Comments) of the Responsiveness Summary.
E16. pg. 2-2 section 2.2.1.1: third paragraph The wording discussing the difference between
CSL and AETs is too confusing. Simply put, the only difference is that SQS and CSL are
TOC normalized, AETs are dry weight normalized.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
Predesign/Contingency Considerations:
El7. There are several "combination" alternatives (i.e. decontamination technologies, partial
removal of CSL/CND with habitat development, capping to SQS) which have not been
proposed or investigated for this site. Integration of adjacent NPL sites (Harbor Island)
should also be investigated when discussing a potential MUDs facility. This may
significantly reduce cost and implementability especially considering potential Lockheed
involvement/at both sites.
See Section 12 (Disposal/Siting) of the Responsiveness Summary.
E18. Additional geological data may be necessary to establish potential volume and/or
construction design modification for a CND facility. This would likely affect cost and
therefore consideration of alternative ranking.
See Section 6.7 (Design IssuesGeneral Issues) of the Responsiveness Summary.
El9. As identified in previous discussions between Ecology and EPA, a pilot scale cap should
be implemented prior to final alternative selection in order to determine if a cap
alternative is viable and to determine potential final costs of this preferred alternative.
See Section 6.7 (Design IssuesGeneral Issues) of the Responsiveness Summary.
E20. It is also imperative to perform highly detailed investigation of the slope and slump
potential. In areas of soft highly contaminated substrate, is a 20 percent slope a
conservative number of slump/containment failure or is this slope based upon "moderate"
substrate material?
See Section 6.2 (Design IssuesGeotechnical) of the Responsiveness Summary.
E2I. The rationale for removal of intertidal CND as a possible alternative were 1) "...it would
be difficult to construct a facility using dredged sediment of the type and contaminant
-------
level this is characteristic of the PSR sediment." and 2)" An intertidal disposal site may
lack capacity to accommodate both PSR and the Lockheed sediment." Additional data,
and/or rationale which substantially supports this conclusion should be presented. It can
be argued that with potential modification in construction and design this alternative is
still viable. In addition, potential solutions to the potential individual hurdles (e.g.
settling rates/consolidation/dewatering) to this alternative should be presented for further
consideration.
See Section 12 (Disposal/Siting) of the Responsiveness Summary.
E22. A significant degree of speculation has been offered with respect to water quality impacts,
settling, dredged sediment behavioral characteristics, consolidation periods etc. Without
further investigation, data, and potential modeling based upon this data, an intertidal
CND alternative should not be dismissed as a potential preferred remedy.
See Section 12 (Disposal/Siting) of the Responsiveness Summary.
E23. Alternative construction techniques should also be explored which will allow efficient
dewatering to occur. This could potentially include increased berm elevation, alternative
construction material, and tide gates to prevent excessive tidal influence. Potential
alternative construction options should also be explored such as extending the eastern and
western berm sides, in order to maximize capacity.
See Section 6.7 (Design IssuesGeneral Issues) of the Responsiveness Summary.
E24. It is unclear how contaminated "mound" areas will be addressed in the capping
alternative.
See Sections 6.1 (Design IssuesCapping at Depth), 6.2 (Design IssuesGeotechnical), and 6.3
(Design IssuesCap Thickness) of the Responsiveness Summary.
-------
FISHERIES DEPARTMENT
Area Code (360)
598-3311
Fax 598-4666
THE SUQUAMISH TRIBE
P.O. Box 498 Suquamish, Washington 98392
May 14, 1999
Sally Thomas
Project Manager
1200 6th Avenue ECL-111
Seattle, WA 98101
Re: Pacific Sound Resources Superfund Site Proposed Plan
Dear Ms. Thomas:
SI. Elliot Bay lies within the Suquamish Tribe's treaty defined Usual and Accustomed
Hunting and Fishing Area (U&A). Within this area, the Tribe holds treaty rights to
natural resources that are impacted by contamination from this and other sites. The Tribe
is an active participant in the Elliot Bay/Duwamish Natural Resource Trustee group, and
incorporates by reference the detailed comments and restoration goals submitted by the
trustees. The Tribe advocates a long-term solution to contaminated marine sediments
throughout the U&A. For this site, EPA's preferred alternative is capping the existing
contaminated marine sediment in place to prevent human and ecological contact. Since
this action does not eliminate existing contamination, the proposed plan is not a
permanent solution. In addition, the proposed plan does not adequately address Treaty
fishing access issues and human health concerns.
See Section 1 (Potential Impacts to Treaty Rights) and Section 13 (Restoration Goals) of the
Responsiveness Summary.
S2. The Suquamish Tribe supports permanent clean up of contaminated sites that will protect
and support harvestable treaty-reserved resources for future generations. In the
evaluation of alternatives, the proposed plan states "the least degree of long-term
effectiveness is provided by capping due to more complex monitoring requirements." If
capping is implemented as proposed, it must be done with the understanding that
permanent removal of contaminants may be necessary in the future. The Tribe
encourages serious consideration of other alternatives that will achieve long-term
effectiveness and permanence.
See Sections 6.6 (Design IssuesLife/Duration) and 11 (Monitoring) of the Responsiveness
Summary.
S3. The plan states that if dredging is chosen as the preferred cleanup alternative, nearshore
disposal would be the preferred disposal option. The Tribe does not consider nearshore
-------
1
disposal an acceptable alternative. Upland disposal is the only method currently beine
considered that would minimize adverse impacts to treaty-reserved resources The
cumulative impact of shoreline development has resulted in a significant loss of
nearshore habitat in Puget Sound. Further fill and subsequent development of nearshore
r and the
See Section 12 (Disposal/Siting) of the Responsiveness Summary.
S4. The proposed plan states that Crowley Marine Services will require dredging of 3 500
cubic yards prior to cap placement. The preferred alternative proposes to move th'is
contaminated dredged material deeper within the off-shore contaminated area prior to
capping The Tnbe recommends that this limited amount of dredged material be
disposed upland or treated prior to replacing it in the aquatic environment.
EPA agrees that upland disposal of the material to be dredged off of Crowley Marine Services
mil be included m the final design. However, there is limited land available for dewateHnzhis
matenal Assuming clamshell dredging, dewatering in 25-cubic-yard containers that can be
transported via truck to a non-hazardous waste landfill will add $688,000 in cleanup costs to the
remedy. Dlfferent methodsfor dewatering (e.g., barge, railcar) will be evaluated prior to finaf
S5. Treaty fishing access issues and human health concerns are not adequately addressed in
the proposed plan. At a minimum, the Suquamish Tribe believes that EPA should
observe MTCA standards for the protection of human health.
See Sections 3 (Risk) and 4 (ARARs) of the Responsiveness Summary.
S6. The proposed plan indicates that all alternatives would entail the establishment of a no
shelifishmg zone through shoreline restrictions for "intrusive recreational activities such
as clamdiggmg ...» Benefits cited in the text of the draft feasibility study include
minimizing the potential for human dermal contact and ingestion of sediments and
reducing the potential for disturbance and resuspension of contaminated sediments
However, the impact on Tribal treaty fishing rights is not addressed, and the text implies
an indefinite foreclosing of shellfishing opportunities. P
See Section I (Potential Impacts to Treaty Rights) of the Responsiveness Summary.
S7. The proposed plan refers to a "no anchor zone" without specifying location and duration
and remains silent concerning potential impacts on Tribal treaty fishing activities This '
aZteTesaddreSSed " ^ ** ** **""* ^ "" * *«d *
-------
fishing opportunity in terms of treaty fishing, it also prolongs injury to trust resources
along with continued adverse human health impacts. We maintain that the emphasis
should be on restoration and clean-up, and that costs entailed in securing clean sediment
from other than the Duwamish River must be calculated and incorporated into the final
clean-up plan.
The duration estimated in the FS is based on the assumption that capping material will be
derived from navigational dredging projects throughout Puget Sound, not just the Duwamish
River. Other sources were considered such as dredging clean sediments in other areas.
However, mining of clean sediment is extremely difficult to get permitted and could also have a
deleterious effect on the benthos if large areas were mined in order to get the quantity of
sediment needed quickly. In addition, capping the sediment over several years will allow the
benthic community to re-establish itself between capping events such that a large area is not
disrupted at one time. Another benefit of capping over several years is that it allows the
effectiveness of capping at depth and over steep slopes to be better established through
monitoring to perfect the operation from one year to the next.
The Suquamish Tribe looks forward to further dialogue concerning habitat and treaty fishing
access issues as EPA works toward the development of a final plan and Record of Decision.
Sincerely,
Randy Hatch
Fisheries Director
-------
MUCKLESHOOT INDIAN TRIBE
'FISHERIES DEPARTMENT
12 May 1999
Ms. Sally Thomas
Remedial Project Manager
U.S. EPA-Superfund
1200 Sixth Ave.,HW-l 13
Seattle, WA 98101
Re: Comments on the following two reports:
1) Pacific Sound Resources Superfund Site Proposed Plan (April 1999);
2) Draft Feasibility Study, Pacific Sound Resource Marine Sediments
Unit, Seattle, Washington (November 1998).
Dear Ms. Thomas,
The Environmental Division of the Muckleshoot Indian Tribe's Fisheries Department has
reviewed the above-referenced documents. As you are aware, the aquatic area that comprises the
PSR Marine Sediments Unit is a very important portion of the Tribe's Usual and Accustomed
Fishing Area. Hence, this area is a location where the Tribe exercises its federally-adjudicated
fishing rights. Adequate cleanup of this area is a necessary step for the protection of the health of
tribal fishers exercising their treaty rights in this area and for the protection of the aquatic
ecosystem which contributes to the health of the fishery itself.
Attached is a summary of general and page-specific comments on the above-referenced
documents. You will find from these comments that the Tribe has substantial concerns about the
adequacy of the cleanup proposed to protect either human health or fish. The Tribe reserves the
right to comment on additional environmental or human health concerns about this cleanup in the
future. -
Thank you for the opportunity to comment on this very important activity. Please feel
free to contact me at (253) 931-0652, extension 130, with any questions or concerns.
Sincerely,
Glen R. St. Amant
Senior Sediment Specialist
Cc: Elliott Bay Natural Resource Trustees
John Malek, EPA
-------
1
' ' '"" I T \A->,, IQQQ
And Draft Feasibility Study
Page 2
12 Mav 1999
Comments on:
Pacific Sound Resources Superfund Site Proposed Plan
General Comments-
M1 a The preferred alternative, identified as capping to CSL, is neither protective of human
health nor protective of impacts to fish from polycyclic aromatic hydrocarbons (PAHs).
Alternative 2 should be screened out by EPA during threshold evaluation, since nsks to
human health exceeding IxlO"4 would remain. As you are aware, this risk level is clearly
inconsistent with EPA's site-specific criteria, remedial action objectives for PSR,
CERCLA guidance, the acceptable risk range identified in MTCA (an ARAR), and the
human health protection afforded by the Washington State Sediment Management
Standards (another ARAR).
See Section 3 (Risk) of the Responsiveness Summary.
M1 b In addition, cleanup of only CSL contaminated sediments at the site does not adequately
protect fish and potentially other aquatic organisms which must rely on this area as
habitat. EPA has received information from the Elliott Bay Natural Resource Trustees on
a PAH level that should be used to define and cleanup the site for restoration purposes.
The level proposed is based upon information about impacts to fish and other aquatic
resources riot addressed in your ecological risk assessment.
See Section 13 (Restoration Goals) of the Responsiveness Summary.
M2 The preferred alternative must be designed in such a way as to allow tribal fishing and
shellfishing activities once the area has been remediated. No institutional controls should
be implemented that would interfere with such activities, as these are protected treaty
rights of the Tribe.
See Section 1 (Potential Impacts to Treaty Rights) of the Responsiveness Summary.
Page-Specific Comments-
M3 Page 1, Bullets. These bullets give the public the mistaken impression that EPA is
proposing to cap all offshore areas that present a risk to human health and the
environment. The first bullet should be rewritten to indicate that the preferred alternative
proposes to cap less than half the area that presents a risk to human health and fish.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
M4 Page 6, last paragraph. This paragraph also gives the mistaken impression that all
' migration from uplands has been eliminated, yet the paragraph above acknowledges that
there is one area where migration from uplands continues to impact sediments and the
aquatic environment. Potential source controls for this area should be included and
evaluated in the Feasibility Study and included, in the Proposed Plan.
-------
Comments on PSR Proposed Plan page 3
And Draft Feasibility Study 12 May 1999
See Section 8 (Source Control and Potential for Recontamination) of the Responsiveness
Summary.
M5. Page 7, last paragraph. There is no evidence whatsoever that EPA considered the
information provided by NOAA on potential risks to fish. The issue is neither discussed
in the risk assessments (except for a sentence or two in the final summary) nor
incorporated into the feasibility study, and apparently had no effect on selection of the
remediation area boundaries. It is not accurate to state that risks to fish from PAHs
cannot be quantified simply because PAHs are metabolized. Other methods of assessing
risks and establishing safe concentrations are available that do not depend on fish tissue
concentrations, and have been provided to EPA by the Elliott Bay Natural Resource
Trustees.
See Section 13 (Restoration Goals) of the Responsiveness Summary.
M6. Page 8, Remediation Objectives. The remediation objectives for human health should
be clearly identified here, as they are in the FS. It should also be stated that the preferred
alternative does not meet EPA's stated human health risk objectives (IxlO"4).
See Section 3 (Risk) of the Responsiveness Summary.
M7. Page 8, Summary of Alternatives. This section again fails to acknowledge the source
area that is affecting sediments west of the former process area.
See Section 8 (Source Control and Potential for Recontamination) of the Responsiveness
Summary,
M8. Page 12, Evaluation of Cleanup Alternatives. Please see detailed comments on the
Feasibility Study.
-------
Comments on PSR Proposed Plan Page 4 1
And Draft Feasibility Study 12 May 1999 '
Comments on:
Draft Feasibility Study
Pacific Sound Resources, Marine Sediments Unit
Seattle, Washington
General Comments-
M9. Human Health. According to the FS, none of the alternatives meets state standards for
protection of human health. In addition, Alternative 2 exceeds even EPA's risk range,
and for this reason should be immediately screened out from consideration. Yet the
feasibility study repeatedly states that all alternatives (except no action) comply with
ARARs.
See Section 4 (ARARs) of the Responsiveness Summary.
M10. Protection of Fish. The remedial action objectives are not protective of the possible
effects of PAHs on fish, which should be a key consideration at this site. There is no
consideration given to this issue in the FS and very little in the supporting risk
assessments. However, it is stated that the levels that would be protective of fish would
be lower than any of the existing alternatives supports.
See Section 13 (Restoration Goals) of the Responsiveness Summary.
Mil. Adequacy of Alternatives. The remedial action objectives should be revised downward,
and additional alternatives should be developed to protect human health and fish, as
discussed above.
See Section 5 (Cleanup Level Selection) and Section 13 (Restoration Goals) of the
Responsiveness Summary.
Ml2. Interference with Tribal Fishing and Shellfish Collection. The submerged nearshore
disposal facility contemplated in the Lockheed FS has been elevated to upland fill in this
FS, and it is not clear that this is necessary to meet project objectives. Such a design
would clearly have the potential to impact tribal treaty fishing access. In addition, all
alternatives state that no shellfish collection and no anchoring of vessels would be
allowed along the shorelines, to protect the integrity of the cap. The cap and fill designs
should be modified to allow Tribal collection offish and shellfish in the area, once
restored, since this should be one of the primary objectives of the cleanup.
See Section 1 (Potential Impacts to Treaty Rights) of the Responsiveness Summary.
M13. Bathymetric Modifications. Some of the alternatives involving dredging result in
unrealistic modifications to bottom depths, including 20-foot discontinuities where
capping and dredging areas meet. There is no discussion of the potential slope stability
problems or habitat alterations that these modifications might create. These alternatives
should be redesigned in a more realistic manner.
-------
Comments on PSR Proposed Plan Page 5
And Draft Feasibility Study 12 May 1999
No bathymetric discontinuities would be allowed in the project design. The FS alternatives were
conceptual in nature and were only intended to be sufficient to select a preferred alternative.
Ml 4. Design Life. The engineering design life of the alternatives is only 30 years, hardly
sufficient to be. protective over the long-term. The design life should be increased to a
much longer timeframe, and provisions made for monitoring and maintenance of any in-
water engineered structures in perpetuity.
See Section 6.6 (Design IssuesLife/Duration) of the Responsiveness Summary.
Ml 5. Comparative Evaluation of Alternatives. The comparative evaluation of the
alternatives overstates feasibility issues of large caps (especially if thin-layer caps are
considered), and downplays much more significant issues associated with dredging and
confined disposal facilities. In addition, it does not give enough emphasis to the lack of
protectiveness and effectiveness of the CSL alternatives over large areas of the site. As
threshold criteria, protection of human health and the environment and compliance with
ARARs should be given more weight than the balancing criteria, and any alternatives not
meeting these thresholds should be screened out altogether.
Under CERCLA, threshold criteria are given more weight in that they must be met for an
alternative to be considered. EPA believes that all alternatives evaluated met the threshold
criteria of Overall Protection of Human Health and the Environment and Compliance wit
ARARs.
Page-Specific Comments-
M16. Page 1-2, last bullet. The design life is too short. Engineered components of the remedy
should be designed to be as permanent as possible. To be protective of human health and
the environment for as long as possible, and to be in better conformance with State land
management planning horizons, a design life of 100-200 years would seem more
appropriate. This is particularly important for engineered facilities such as nearshore
confined disposal, where failure could result in catastrophic contamination of large areas.
See Section 6.6 (Design IssuesLife/Duration) of the Responsiveness Summary.
Ml7. Page 1-3, last bullet. The paragraph on the previous page states that remedial action
goals were developed in consultation with the Washington Department of Ecology, yet
the remedial action goal in this bullet calls for a level of protection of human health of
only 1 in 10,000. This is higher than the maximum legally allowable under the
Washington Model Toxics Control Act, which is 1 in 1,000,000 for individual chemicals
and 1 in 100,000 for cumulative risks. These are numeric ARARs that must be met under
Superfund. Information in the Feasibility Study and its appendices does not support the
claim that the risk level or the preferred alternative is in compliance with applicable laws.
If the EPA continues to make such claims, the Tribe requests a detailed explanation on
how all aspects of MTCA and SMS are addressed by the proposed approach.
See Section 4 (ARARs) of the Responsiveness Summary.
-------
Comments on PSR Proposed Plan Pa 6 f
And Draft Feasibility Study 12 May 1999
M18. Page 1-7, third paragraph. The text states that no seepage of oil has been observed
along the shoreline since the slurry wall was installed, but does not describe whether or
how often the shoreline has been monitored for seepage, and whether the monitoring
included very low tides when such seepage would be most likely to be evident.
These observations are based on casual observations made during other work in the shoreline
(including low tide period) (Brian Stone, pers. com. with Larry Vanselow-WESTON 8/2/99).
Currently, no formal inspection of the shoreline is included in the Upland Unit long-term
monitoring plan. See response to T-9.
M19. Page 1-12, last paragraph. Chinook have now been listed, and various references to it
throughout the report should be updated.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
M20. Page 2-2, Chemical Screening Criteria. The phrase "biological resources" in the first
paragraph should be replaced by "benthic infauna". The SMS chemical criteria are
designed to be protective only of benthic organisms and do not necessarily provide
protection offish, shellfish, birds, mammals, or other biological resources in Elliott Bay.
In the second paragraph, SMS chemical criteria cannot be used to assess protection of
human health. Ecology and the PSDDA agencies (including EPA Region 10) have been
very clear that this in an inappropriate use of AETs. In human health guidance
documents published by Ecology and WDOH (1995, 1996), it was established that
protective sediment concentrations for some of the bioaccumulative contaminants at the
site (e.g., PCBs, dioxins/furans) would be lower than values protective of benthic
organisms (in part because benthic organisms lack the receptors that mediate toxicity of
these compounds).
Separate screening values should be developed for each of these other types of receptors
using appropriate risk- or effects-based values provided in the literature and/or developed
for other sites.
See Section 5 (Cleanup Level Selection) of the Responsiveness Summary.
M21. Page 2-Vlast paragraph. Background concentrations should be taken from approved
Puget Sound reference areas; such values for bioaccumulative compounds can be found
in DOH (1995), Appendix A, and PSEP (I991a,b). Elliott Bay concentrations should be
considered "ambient" or some other phrase that does not imply a lack of contamination.
Station BK02 is suspect, as its concentration was markedly higher than other stations in
Elliott Bay. If these values are used for screening dioxin/furan concentrations, BK02
should be removed as an outlier and the remaining stations averaged, as inclusion of this
station is currently resulting in an "average" concentration well above that in most areas
of Elliott Bay.
Background sample locations (i.e., Duwamish Head, Magnolia Bluff, and Myrtle Edwards Park)
were selected to represent conditions in Elliott Bay outside the influence of PSR. Data from
these locations were used in their entirety; however, comparisons to background were not used
-------
Comments on PSR Proposed Plan
And Draft Feasibility Study 12 May UK*
to establish risks. Rather body burdens associated with deleterious effects (derived from the
literature) were used as the comparison endpoint to quantify ecological risks. See also Section 3
(Risk) of the Responsiveness Summary.
M22a. Page 2-5, last paragraph, and page 2-6. It is not acceptable to ignore potential effects
to fish from PAHs at the site, since PAHs are the primary contaminant of concern, fish
listed under ESA are present at the site, and the literature that is available on effects of
PAHs to fish is specific to fish that are abundant near the site (English sole). The ESA
listing necessitates an approach somewhat more protective than might otherwise be
employed at a Superfund site. This characterization of the results of the ecological risk
assessment is incomplete and leaves out one of its key conclusions, as stated in the
executive summary to Appendix K of the RI Report: "... significant deleterious impacts
can occur at PAH concentrations several times to an order of magnitude lower than the
concentrations that cause effects in benthic invertebrates. Given that this range of
concentrations is similar to the levels in sediment that would be protective of people
eating shellfish, cleanup decisions based on human health issues will likely protect fish."
See Section 5 (Cleanup Level Selection) and Section 13 (Restoration Goals) of the
Responsiveness Summary.
M22b. No remedial action objectives have been proposed that are protective of either human
health or fish at the site, and no remedial alternatives have been developed that would
reduce these risks to acceptable levels. Protectiveness of the remedy to fish, shellfish,
and tribal members fishing for and consuming these resources is of primary concern to
the Tribe, and the FS should be rewritten to include and evaluate alternatives that are
protective of these resources, in conformance with federal and state law.
See Section 4 (ARARs) of the Responsiveness Summary.
M23. Page 2-7,2.4.1.2 Washington State Water Quality Standards. The water quality
standards also include other requirements, such as no visible sheen, that are likely to be
applicable to this site both during and after active remediation. In addition, the water
quality standards set out specific characteristic uses for each water body that must be
maintained, including protection of fish and shellfish, and fisheries based on these
resourcesr The remedial action objectives should be designed to ensure that these uses of
the water body are protected.
See Section 10 (RAOs /Evaluation Criteria) of the Responsiveness Summary.
M24. Page 2-7, 2.4.1.2 Washington Sediment Management Standards. This section
misinterprets the narrative definitions within the SMS. Again, "biological resources"
should be replaced with "benthic organisms". The definition of SQS provided in WAC
173-204-100 is a narrative definition of the SQS, intended to guide site-specific
development of numeric RAOs. It is not meant to imply that the numeric criteria that
have been promulgated for the protection of benthic organisms are also protective of
human health or other higher trophic level receptors. Numeric criteria protective of
human health have been reserved, and site managers are expected to develop such criteria
-------
Comments on PSR Proposed Plan p g
And Draft Feasibility Study 12 May ,|99
on a site-specific basis (WAC 173-204-320(4)). Ecology and DOH guidance (DOH,
1995) on the protection of human health clearly indicates that there are a number of'
bioaccumulative chemicals for which the benthic criteria will not be protective of human
health (or other higher trophic level receptors). A maximum cumulative risk level of
1x10- has been selected by Ecology as corresponding to the CSL, while a cumulative risk
level of 1 x 10 has been selected as a human health risk level corresponding to the SQS
(see draft rule language). These risk levels are consistent with MTCA.
See Section 3 (Risk) of the Responsiveness Summary.
M25. Page 2-7, Section 2.4.1.4. The numeric human health risk levels included in MTCA
should be referenced, as they are ARARs applicable to Superfund sites.
See Section 4 (ARARs) of the Responsiveness Summary.
M26a. Page 2-12, bullets. Neither of these RAOs is adequate to protect human health and the
environment at the site. The human health risk level does not comply with MTCA risk
levels or draft SMS human health risk levels. The SQS/CSL chemical criteria are as
much as an order of magnitude higher than levels protective of impacts to fish from
PAHs present at the site.
See Section 4 (ARARs) of the Responsiveness Summary.
M26b Alternative RAOs should be developed that better reflect state and federal regulations and
risks to humans and fisheries resources, and the areas and volumes used to design the
remedial alternatives should be adjusted accordingly. Regardless of the remedial action
ultimately selected, the FS should be more forthright about the risks that are present and
the areas that exceed these risks.
See Section 10 (RAOs /Evaluation Criteria) of the Responsiveness Summary.
M27. Page 3-1, bullet. This paragraph should be rephrased so that it does not state that "no
action/institutional controls" will meet the project RAOs.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
M28. Page 4-5, first paragraph. The prevailing winds may be from the southwest, but the
winter storms that generate the most wave action are typically from the north.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
M29. Page 4-5, Capping Material Availability. It would be easier to put this discussion in
context if it was stated how much capping material was projected to be needed for the
various alternatives.
The alternatives with a significant capping element as part of the remedial approach would
require befiveen 363,000 to 778,000 cubic yards of capping material depending on which
alternative was selected.
-------
Comments on PSR Proposed Plan Page 9 I
And Draft Feasibility Study 12 May } 999 *
M30. Page 4-6, first full paragraph. Rejection of the lower Duwamish material because it is
siltier does not make sense - earlier in the test it stated that sillier material would be
better at containing contaminants. Because of its higher organic matter content, it
typically also provides a better substrate for recolonization by benthic organisms. Clean,
silty sands may therefore be a better capping material than sand alone. However, a good
reason to reject lower Duwamish material would be if it had higher levels of
contamination than other sources of capping material.
See Section 6.4 (Design IssuesCap Source Material) of the Responsiveness Summary.
M31. Page 4-6, Cap Placement. There's no particular reason why capping could not be
considered for areas > 200 ft. deep - a demonstration capping project was recently
completed on the margins of the PSDDA site in Elliott Bay, which is substantially deeper
than 200 ft. In particular, thin-layer capping could be conducted in almost any depth of
water, since it does not require that an evenly thick cap be placed.
See Section 6.1 (Design IssuesCapping at Depth) of the Responsiveness Summary.
M32. Page 4-10, Institutional Controls. Any caps along the shoreline should be sufficiently
adequate to allow tribal collection of shellfish resources, including clams, once the site is
cleaned up, since one of the primary reasons to conduct the cleanup is to protect and
restore fisheries resources and better support Tribal treaty rights to gather fish and
shellfish in the area. Cleanup should also be adequate to support the use of the area as a
Tribal net fishery, which could include use of anchors with nets
See Section I (Potential Impacts to Treaty Rights) of the Responsiveness Summary.
M33. Page 4-12, Long-Term Capped Area Monitoring. The cap should maintain its
integrity for more than 30 years. Provisions should be made for inspections and cap
maintenance over the long term. If, during the first 30 years, any problems are identified
with cap integrity, a more permanent solution or an ongoing (permanent) maintenance
program should be established.
See Sections 6.6 (Design IssuesLife/Duration) and II (Monitoring) of the Responsiveness
Summary. *-.
M34. Page 4-13, first full paragraph. The ability of the cap to withstand storms and waves
may depend on whether the elevation of the bottom is being changed. Placement of the
cap in a manner that increases bottom elevations may make it more exposed to wind
waves, wakes, and storm events.
See Section 6.5 (Design IssuesCap Placement) of the Responsiveness Summary.
M35. Page 4-15, Potential for Recontaminarion. It is really not clear that the measures
proposed will prevent eventual recontamination of this area. The design modification of
using a sandy cap is particularly troubling because it implies that, rather than allowing the
PAHs to sorb onto the cap materials, they will be allowed to pass through and be released
-------
Comments on PSR Proposed Plan Page 10
And Draft Feasibility Study 12 May 1999
into the water column. It does not seem like this approach would reduce exposure to the
receptors of concern (e.g., English sole and juvenile salmonids). Source control is
generally considered a more appropriate and effective approach to recontamination
concerns than engineering modifications to the receiving environment. To ensure that the
potential for recontamination is minimized, source removal, DNAPL pumping, and/or
further migration barriers along the shoreline should be considered as part of the cleanup
alternatives.
See Section 8 (Source Control and Potential for Recontamination) of the Responsiveness
Summary.
M36. Page 4-18, Removal to CSL. This alternative would raise the elevation in intertidal
areas by as much as three feet, while dredging in adjacent nearshore areas to as much as
16 feet. Since no backfill of dredged areas are proposed, a bathymetric discontinuity of
up to 20 feet could be created. The slopes in this area are already steep. The engineering
feasibility of this approach should be discussed, and provision made for a method to leave
a reasonable slope in this area. For this and all alternatives that change bottom elevations
in nearshore areas, the impact of these changes on habitat and fisheries resources should
be discussed.
The alternatives presented in FS were conceptual and were not intended in include the level of
detail discussed in this comment. No bathymetric discontinuities would be allowed in the actual
design.
M37. Page 4-20, Capping to SQS. All other constituents in the capping material should also
be less than the SQS (not just PAHs).
Chemical concentrations in potential capping material must meet the SMS for all constituents for
which there are standards.
M38. Page 5-5, Compliance with ARARs. Alternative 2 does not comply with ARARs,
particularly SMS human health guidance or promulgated MTCA human health risk
limits, both of which require that cumulative human health risks be reduced below IxlO"5.
The residual risks of this alternative are even above EPA's acceptable risk range (upper
limit of txlO^1). Alternative 2 entails substantial modification of bathymetric contours in
shallow subtidal areas if no clean backfill is proposed, which may or may not comply
with the Washington Hydraulics Code.
See Section 4 (ARARs) of the Responsiveness Summary.
M39. Page 5-10, Compliance with ARARs. Alternative 3a begins to get close to SMS/MTCA
required risk ranges, but Alternative 3b is well above the acceptable risk limit. It is not
clear why Alternative 3b is expected to have lower risks than Alternative 2, when both
address the same area (sediments > CSL). The same comments apply to Alternatives 4a
and 4b, on Page 5-14.
See Section 3 (Risk) of the Responsiveness Summary.
-------
Comments on PSR Proposed Plan Page 11
And Draft Feasibility Study 12 May 1999
M40a. Page 5-18, fourth paragraph. Here and in other places throughout the FS, a better
explanation should be provided of why it would be so difficult to inspect and monitor the
cap or CAD site. The PSDDA site is in deeper water and it has been very effectively
monitored over the years, for relatively low cost.
See Section 11 (Monitoring) of the Responsiveness Summary.
M40b. Page 5-18, fourth paragraph. How likely is anchor drag or other damage to the CAD
surface in these relatively deep waters?
See Section 6.3 (Design IssuesCap Thickness) of the Responsiveness Summary.
M41. Page 5-20, second paragraph. A tremie pipe could be used to place these contaminated
sediments in deep water, limiting losses to the water column and allowing better
placement of materials.
See Section 6.5 (Design IssuesCap Placement) of the Responsiveness Summary.
M42. Page 5-30, last paragraph. As noted above, none of the existing alternatives meets State
ARARs for protection of human health.
See Section 4 (ARARs) of the Responsiveness Summary.
M43. Page 5-32, Long-Term Effectiveness and Permanence. For the same reason that the
no-action alternative provides the least long-term effectiveness, alternatives that clean up
only to the CSL will have lower long-term effectiveness than those that clean up to the
SQS, since CSL alternatives take no action over large areas that exceed risk levels for
human health and the environment.
See Section 3 (Risk) of the Responsiveness Summary.
M44. Table 5-6. Because none of the alternatives is fully protective of human health or meets
State ARARs, the alternatives should receive different scores for this criterion based on
whether they come close to achieving the human health ARAR or not. On this basis,
Alternatives 3a and 4a would receive higher scores than the others. Similarly, these
alternatives should receive a higher score in reduction of mobility, since they will
effectively contain a much larger percentage of the sediments that pose a risk to human
health and fish.
EPA believes that all alternatives evaluated meet ARARs with respect to protection of human
health. Please see EPA's responses to Section 3Risk. Reduction in contaminant mobility is
evaluated for treatment options only and does not apply to remedies based on confinement.
References
Ecology. 1997. Developing Health-Based Sediment Quality Criteria for Cleanup Sites: A Case
Study Report. Washington Department of Ecology, Olympia, WA.
-------
Comments on PSR Proposed Plan page 12
And Draft Feasibility Study 12 May 1999
EPA. 1993. Interim Report on Data and Methods for Assessment of 2,3,7,8-
Tetrachlorodibenzo-p-dioxin Risks to Aquatic Life and Associated Wildlife. Office of Research
and Development, Washington DC. EPA/600/R-93/055.
Homess, BH, DP Lomax, LL Johnson, MS Myers, SM Pierce, and TK Collier. 1998. Sediment
Quality Thresholds: Estimates from Hockey Stick Regression of Liver Lesion Prevalence in
English Sole. Environmental Toxicology and Chemistry 17(5):872-882.
PSEP. 199 la. Pollutants of Concern in Puget Sound. Puget Sound Estuary Program. EPA
910/9-91-003.
PSEP. 1991b. Reference Area Performance Standards for Puget Sound. Puget Sound Estuary
Program. EPA 910/9-91 -041.
WDOH. 1995. Tier I Report, Development of Sediment Quality Criteria for the Protection of
Human Health. Washington Department of Health, Olympia, WA.
WDOH. 1996. Tier n Report, Development of Sediment Quality Criteria for the Protection of
Human Health. Washington Department of Health, Olympia, WA.
-------
MUCKLESHOOT INDIAN TRIBE
FISHERIES DEPARTMENT
13 May 1999
Ms. Sally Thomas
Remedial Project Manager
U.S. EPA - Super-fund
1200 Sixth Ave., HW-113
Seattle, WA 98101
Re: I) Elliott Bay/Duwamish River Natural Resource Trustee joint
comments on the PSR draft Feasibility Study and Proposed Plan.
2) Transmission of Trustee Restoration Goals for the PSR Site.
Dear Ms. Thomas,
On behalf of the Elliott Bay/Duwamish River Natural Resource Trustees
(Trustees), please find the attached joint comments on the draft Feasibility Study and the
Trustee Restoration Goals for the PSR Site. As warranted, individual Trustees will be
corresponding with you directly with any additional comments they may wish to provide
you on the PSR reports. The Trustees have not provided separate joint comments on
EPA's Proposed Plan for the PSR Site, although comments on the draft Feasibility Study
should be addressed in the Proposed Plan, as appropriate. The Restoration Goals are
provided to EPA to better ensure that the selection and design of remedial actions at the
PSR site are consistent with these goals.
Thank you for the opportunity to comment and coordinate on this very important
activity. Please feel free to contact me at (253) 931-0652, extension 130, with any
questions or^oncerns.
Sincerely,
Glen R. St. Amant
Senior Sediment Specialist
Cc: Elliott Bay/Duwamish River Natural Resource Trustees
39015 172nd Avenue Southeast Auburn, Washington 98092 (253)931-0652 FAX (253) 931-0752
-------
-------
August 4, 1999
General Comments on the Draft Feasibility Report-
Tl. The Trustees do not agree that the proposed preferred alternative, capping to the Cleanup
Screening Level (CSL), should be selected for the PSR site. The Trustees believe that
cleanup at the site should incorporate the attached Restoration Goals, including the
identified sediment cleanup goal of 2,000 parts per billion dry weight for total polycyclic
aromatic hydrocarbons.
See Section 13 (Restoration Goals) of the Responsiveness Summary.
T2. Long-term effectiveness of the proposed remedy is very important. Source control must
be implemented concurrent to remediation to better assure the long-term success of
cleanup. The draft Feasibility Study predicts recontamination of a portion of the capped
sediments within 10 years, due to uncontrolled migration of contaminants through
groundwater. This is inconsistent with the Sediment Management Standards ARAR
(WAC 173-204-570) and permissible cleanup standards. The Trustees do not consider
reducing the organic carbon content of the cap material to be an appropriate measure for
addressing this problem. Other measures to prevent recontamination should be identified,
and the ROD should include a specific commitment to address the recontamination of
sediments should it occur.
See Section 8 (Source Control and Potential for Recontamination) of the Responsiveness
Summary.
T3. The cost analysis of the proposed remedial and disposal options (Section 5) are currently
misleading and should include estimates for mitigation and/or access and easement costs
when applicable. These additional estimates would allow a more readily comparable
cost-benefit ratio of the proposed cleanup and disposal alternatives.
\
The estimates have been revised to include mitigation. No estimate ofDNR land use costs can be
made at this time. The revised estimate for each of the alternatives are provided below. The first
table gives the oestsfor habitat mitigation, based on mitigation cost estimates from
Commencement Bay projects. Because the nearshore disposal sites are predominantly subtidal,
a habitat mitigation ration of 1:1 was used. No mitigation was assumed to be necessary for a
CAD; capping was assumed to be "self-mitigating. " The second table provides the cost of all
the alternatives including habitat mitigation costs.
Page 1
-------
Mitigation Cost Estimates
Alternative
2 - Dredge to CSLs
2 - Dredge to CSLs
3a - Cap to SQS
3b - Cap to CSLs
4a - Dredge/Cap to SQS
4a - Dredge/Cap to SQS
4b - Dredge/Cap to CSLs
4b - Dredge/Cap to CSLs
Disposal
Method
CAD
Nearshore
Cap
Cap
CAD
Nearshore
CAD
Nearshore
Land
Use
(Acres)
16
17.5
96
47
16
17.5
12.5
14.5
DNR Use
Cost per
Acre ($)
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Land Use
Cost ($)
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Mitigation
Area
(Acres)
N/A
17.5
N/A
N/A
N/A
17.5
N/A
14.5
Mitigation
Cost per
Acre ($)
.
300,000
-
-
-
300,000
-
300.000
Mitigation
.
5.250,000
.
_
_
5,250,000
4,350,000
Alternative Estimates (includes mitigation costs)
Alternative
2 - Dredge to CSLs
2 - Dredge to CSLs
2 - Dredge to CSLs
3a - Cap to SQS
3b - Cap to CSLs
4a - Dredge/Cap to
SQS
4a - Dredge/Cap to
SQS
4a - Dredge/Cap to
SQS
4b - Dredge/Cap to
CSLs
4b - Dredge/Cap to
CSLs
4b - Dredge/Cap to
CSLs
Disposal
Method
CAD
Nearshore
Constructed
Upland
Established
Upland
Established
Upland
CAD
Nearshore
Constructed
Upland
CAD
Nearshore
Constructed
Upland
Remediation
Cost
6,010.000
6.010,000
6.010,000
12,520.000
6.440.000
12.430.000
12.430.000
12.430.000
5,500.000
5,500.000
5,500.000
CAD
Disposal
Cost ($)
7,704,000
-
-
«
-
7.902,000
-
-
5,670,000
-
-
Nearshore
Disposal
Cost ($)
.-
11,128,000
-
11.414,000
-
8.190.000
Upland
Disposal
Cost ($)
19,260,000
619,000
619.000
19,755.000
14,175,000
Habitat
Mitigation
Cost ($)
-
5.250.000
-
-
-
5.250,000
-
4,350,000
Total Cost ($)
13.714,000
22.388,000
25.270,000
13.139,000
7,059,000
20.332.000
29,094,000
32,185.000
11,170,000
18,040,000
19,675,000
T4a. Several aspects of the capping scenarios discussed for the site need clarification and
additional discussion. Portions of the site with very steep slopes (i.e., greater than 18 to
20%) present serious challenges for proper cap placement and cap stability. More
Page 2
-------
thorough discussion of the feasibility of placing and maintaining a cap in these areas is
warranted.
See Section 6.2 (Design IssuesGeotechnical) of the Responsiveness Summary.
T4b. In addition, statements are made about the selection of the proper capping material grain
size and coarseness for maintenance of cap integrity. Cap design should also address the
potential to integrate similar grain size fractions to the existing bottom, to help promote
biological colonization and recolonization of species that will be displaced by the cap.
See Sections 6.1 (Design IssuesCapping at Depth) and 6.3 (Design IssuesCap Thickness) of
the Responsiveness Summary.
T4c. Finally, any discussion of cap design should also address the following functions:
physical isolation, stabilization of sediment, and reduction in flux, (i.e., chemical
isolation).
See Section 6.3 (Design IssuesCap Thickness) of the Responsiveness Summary.
T5. The Trustees are interested in participating in the remedial design process that evaluates
and selects the specific remediation activities ultimately employed at the site. For
example, issues such as the type of dredge bucket selected and timing of the proposed
action may have important recontamination or other environmental implications. At the
time that these issues are being discussed, please notify the Trustees, in advance, so that
we may be able to coordinate with EPA on these issues.
During design, EPA will provide design documents and monitoring plans to the Trustee and
regulatory agencies. As with the RI/FS process, EPA may hold technical meetings in advance of
the preparation ofdeliverables to solicit ideas from reviewing agencies to assure that issues
have been identified and discussed early on.
Page-Specific Comments on the Draft Feasibility Report-
Id. Page 1-2, First Paragraph, The phrase "to the extent practicable" should be changed to
"to the maximum extent practicable" to conform to the Model Toxics Control Act
(MTCA) cleanup regulation language (Chapter 173-340, WAC).
See Section 14 (Editorial Comments) of the Responsiveness Summary.
T7. Page 1-3, Fourth Bullet. The PSR Site Criteria of a human health excess cancer risk of
less than I in 10,000 is inappropriate. ARARs for the site include MTCA and the
Washington State Sediment Quality Standards. MTCA allows for a maximum of 1 x 10~5
cancer risk for multiple chemical exposure (MTCA Cleanup Regulation, WAC 172-340-
708). This comment significantly affects other sections of the document, which should be
revised accordingly.
See Section 4 (ARARs) of the Responsiveness Summary.
Page 3
-------
T8. Page 1-4, Section L3.2, Third Paragraph. Please change the phrase "treaty rights to
gather shellfish" to "treaty rights to gather other fish and shellfish." Also, please delete
the last sentence in the paragraph, and the associated Figures 1-7 and 1-8. The figures are
inaccurate and the previous sentences in the paragraph adequately state that the Tribes
fish in the area.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
19. Page 1-4, Section 1.3.3.1, Last Paragraph. Please explain why no LNAPL has been
collected in the recovery trench. Is this expected or is the product migrating somewhere
else?
During the remedial investigation of the Upland Unit, LNAPL was found to be very localized and
occurrence was sporadic. However, there was some uncertainty regarding the volume of LNAPL
that may be present, so a collection trench was added on the upgradient side of the wall to
collect any LNAPL that may be floating on groundwater towards Elliott Bay. Since completion
of the wall and trench, no LNAPL has been observed, confirming the suspicion that LNAPL was
minimal at the site. The lack of LNAPL may be due, in part, to the limited use of
pentachlorophenol (PCP) as a wood preservative at the PSR site. LNAPLs at this site would
primarily be generated from the carrier oils used to apply PCP.
T10. Page 1-8, Section 1.4.6, Second Paragraph, Fourth Line. Please change the first word
in this line from "estuary" to "Waterway."
See Section 14 (Editorial Comments) of the Responsiveness Summary.
Til. Page 1-13, First Full Paragraph. Some mention should be given to include the pocket
beaches at or near the site as additional habitat potentially used by the great blue heron.
// MT recognized that piscivorous birds may utilize the site. It should be also noted that exposed
beach is limited to 72 days per year and provides only a fraction of the total fishing area that
may be utilized by a heron.
T12. Pages 1-14 and 1-15. This paragraph mentions the potential recontamination of a portion
of the M6U by naphthalene and fluorene. How does EPA plan to handle cleanup
situations where recontamination does occur? EPA should elaborate on further actions or
contingency plans for handling ongoing sources of DNAPL as well as deep groundwater
contamination in this section and throughout the document.
See Section 8 (Source Control and Potential for Recontamination) of the Responsiveness
Summary.
Tl 3. Page 2-2, First Full Paragraph. This paragraph should clearly state that the SQSs and
CSLs are Washington State-derived numbers. The term "biological resources" should
also be replaced with "benthic infauna."
See Section 14 (Editorial Comments) of the Responsiveness Summary.
Page 4
-------
1
T14. Page 2-2, Section 2.2.1.1, Second Paragraph. Insert the following as a second sentence:
"However, the SMS does have a narrative standard for human health of no significant
health risk to humans."
See Section 14 (Editorial Comments) of the Responsiveness Summary.
T15. Page 2-3, Section 2.2.1.2, Second to the last sentence. Please explain why only detected
values were used to calculate 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalents as
opposed to also utilizing some value for the samples that were below detection limits.
This method of summing dioxins is similar to the method used under the SMS for creating
composite chemical concentrations (e.g., total benzqfluoranthenes, total LPAHs, total PCBs, etc).
This approach was considered reasonable by WESTON's risk assessors and was used for the PSR
MSU evaluations.
Tl 6. Page 2-3, Section 2.2.2, Second Paragraph. Please specify types (i.e., congener-specific
or total families) of compounds found to exceed screening levels. For example,
dibenzofuran is a specific type of furan, so "total" dioxins/furans were found, as well as
the specific furan, to exceed screening levels. Also, when referring to PCBs, please state
"total" PCBs, if that is what is meant here and throughout the document.
Individual congeners were analyzed; a total TCDD/TCDF concentration was created by
applying toxicity equivalency factors to each group and then summing. Please see the RI risk
assessment for further details regarding treatment of dioxins andfurans. Total PCBs refers to
the sum of detected Aroclors reported for each sample.
T17. Page 2-7, Section 2.4.1.3, Second Paragraph. This paragraph is an inaccurate
interpretation of the SMS rule. The SQS numeric criteria do not necessarily protect
human health. They are developed by the State to protect the benthic community. The
level of protection needed to meet the SQS narrative standard for human health must be
determined on a site-specific basis.
See Section 3 (Risk) of the Responsiveness Summary.
T18. Page 2-M, Section 2.4.3.1, Last Sentence. Please replace the phrase "from the
Department of the Interior" to "from the Department of Interior and/or the Department of
Commerce, acting through the U.S. Fish and Wildlife Service and the National Marine
Fisheries Service, respectively."
See Section 14 (Editorial Comments) of the Responsiveness Summary.
T19. Page 2-10, Section 2.4.3.3, Title. Please remove "U.S." from Fish and Wildlife
Coordination Act.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
Page5
-------
See Section 4 (ARAKs) of the Responsiveness Surnrna^,.
See Section 14 (Editorial Counts) of the Responsiveness Summary.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
T23< i^^^^^^rS"8 -* capped *
the long-term success of the remedial act^ A?' " f ^ inadequate to detene
would be included for anal^s s EPA shlld indud^ ^ IS .""^ ^ °nly P ^
PCBs, in the monitoring prograir Tto i £^ ^12°* *""* of ana1^, especially
the remedial action. For exaSS reconZTnl ^f ^ Iong-term efficacy °f
resulting in non-PAH »««2iSSS^^ All S^Prn "^ ^^"^
be congener-based, rather than Aroclor based for h » PCB analysis should
significance. 5aSed' for better interpretation of toxicological
See Section 11 (Monitoring) of the Responsiveness Summary.
^^
"Jnoraons allow, sampling frequency would then be
See Section 14 (Edilorial Commen,s) of, he Responsiveness Sumntary,
contro1 is
example given in «himg±h ^eHtaf/ ^Slora?wl Goals)' ° Argument and
attained concurrent to ? """ SOUrCe COntrol needs to be
attained concurrent to remea! actton
4
-------
See Section 14 (Editorial Comments) of the Responsiveness Summary.
T26b. Also, the Trustees believe that alternatives such as dredging to SQS or dredging to CSL
and then capping to SQS as well as other cleansing/bioremedial technologies need to be
reexamined at this point in the feasibility study.
A number of alternatives were screened as part of the FS process and were summarized in the FS
report; the screening technical memorandum was reviewed by Trustee and regulatory agencies.
Dredging to the SQS was not considered feasible due to the technical difficulties associated with
dredging at depths greater than -200 feet MLLW, volumes generated (970,000 cubic yards) and
the resulting cost of disposal ($60,000,000, assuming construction of a nearshore disposal
facility) and was therefore not carried forward in the FS. Various treatment technologies were
evaluated during the screening process. None are currently available as a cost-effective remedy
at this time. Should a long-term, regional facility be developed, treatment may become a viable
remedial technology for the Puget Sound region. The Superfund process recognizes that new,
more cost-effective technologies may be developed over time. This is one of the reasons
remedies are only costedfor a 30-year life.
121. Page 4-18, Section 4.2.2, Third Sentence. Include a statement that allows for dredging
of shoreline or areas close to shore in which shore protectiveness and slope instability are
not issues.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
T28. Page 4-18, Section 4.2.2.2, Second Paragraph, Last Sentence. Since PCBs are also of
concern in certain areas of the site, include a statement which encompasses the idea that
PCBs will also be dredged to appropriate levels in those areas.
See Section 5 (Cleanup Level Selection) of the Responsiveness Summary.
T29. Pages 4-20 through 4-22, Section 4.2.3. Add a discussion in this section to address
hydrology and changes in hydrology to the area after placement of a large cap (i.e.,
explain how wave, currents, and wind impacts will change). Also, add a discussion
section on any alternatives that could be employed to complete capping over a faster
duration Than proposed.
See Sections 6.2 (Design IssuesGeotechnical) and 6.3 (Design IssuesCap Thickness) of the
Responsiveness Summary.
T30. Page 4-20, Section 4.2.3.1, First Paragraph, Last Sentence. Please revise the PAH
chemical concentration of the capping material to be consistent with the Trustees'
primary restoration goal of less than or equal to 2,000 parts per billion dry weight.
See Section 3 (Risk) and Section 13 (Restoration Goals) of the Responsiveness Summary.
Page?
-------
T31. Page 4-20, Section 4.2.3.1, Third Paragraph. Is wave or wind energy a concern for the
stability of the shoreline cap? Please explain. This comment also applies to Section
4.2.3.2, Second Paragraph.
See Sections 6.2 (Design IssuesGeotechnical) and 6.3 (Design IssuesCap Thickness) of the
Responsiveness Summary.
T32. Page 4-26, Section 4.3.2, First and Second Paragraphs. The first paragraph states that
CND sites cannot conflict with tribal fishing activities. However, the nearshore areas
retained for consideration are within Tribal fishing areas. These two statements
contradict one another and should be rewritten.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
T33. Page 5-5, Section 5.3.2.2, First Paragraph. The risk levels obtained by this alternative
are not consistent with ARARs. Please refer to comments on pages 1-3 and 2-7.
See Section 4 (ARARs) of the Responsiveness Summary.
T34. Page 5-6, Section 5.3.2.2, First Paragraph. This paragraph mentions that the alternative
would comply with all appropriate dredge requirements under the Clean Water Act.
However, no mention is made of the ultimate disposal method being proposed for the
dredged material. Please discuss the proposed disposal method, location, and any
associated environmental impact issues.
See Section 12 (Disposal/Siting) of the Responsiveness Summary.
T35. Page 5-9, Section 5.3.2.7, Last Sentence. It seems that some form of cost estimate for
disposal should be applied in this section, since the alternative could not be accomplished
without disposal.
See Section 12 (Disposal/Siting) of the Responsiveness Summary.
T36. Page 5-10, Section 3.3.2, First Paragraph. The risk levels associated with Alternative
3b are net consistent with ARARs. Please refer to comments on pages 1-3 and 2-7.
See Section 4 (ARARs) of the Responsiveness Summary.
T37. Page 5-11, Section 5.3.3.4, Third Paragraph, Last Sentence. The Trustees encourage
EPA to evaluate the upland disposal of the 3,500 cubic yards of dredged materials, since
upland disposal would lessen the environmental impacts associated with moving them to
another location in deeper water at a minimal cost.
The ROD will include upland disposal of the material dredged near Crowley-Marine at a cost of
$688,000.
PageS
-------
T38. Page 5-13. Fourth Full Paragraph, Second Sentence. In circumstances where remedial
activities may impact Tribal fishing, EPA should coordinate directly with the Tribes.
This comment applies to all areas in the report that discuss potential impacts to Tribal
fishing.
See Section I (Potential Impacts to Treaty Rights) of the Responsiveness Summary.
T39. Page 5-14, Section 5.3.4.2, First Paragraph, Fourth Line. Please change "CLS" to
"CSL." (typographical error).
See Section 14 (Editorial Comments) of the Responsiveness Summary.
T40. Page 5-23, First Paragraph. The Trustees suggest deleting the sentence that states, "The
area lost, however, is currently highly contaminated, providing low-quality habitat for
fish." This sentence is not needed in the paragraph, and is not necessarily accurate. This
paragraph should also note that habitat mitigation would likely be a requirement of this
disposal alternative.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
T41. Page 5-25, First Full Paragraph. The Trustees suggest deleting the following from the
paragraph: "that now provide low quality habitat for native marine communities. The
present ecological values of these sites are limited by existing contamination." See the
explanation in the previous comment.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
T42. Page 5-25, Section 5.4.2.6, Third Paragraph, Sixth Line. Please delete the following:
"The area lost, however, is currently contaminated and provides low-quality habitat for
fish. In addition,". See the explanation in the two previous comments.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
T43. Page 5-25, Section 5.4.2.6, Fourth Paragraph. This paragraph states that the CND
would have no long-ranging impacts on water-dependent industries. However, this CND
eliminates an area used for Tribal Fishing. Please rewrite.
See Section 14 (Editorial Comments) of the Responsiveness Summary.
T44. Page 5-26, Section 5.4.2.7. The cost estimate for this alternative does not include habitat
mitigation costs. These costs should be included, since they could be significant, and
since habitat mitigation will likely be required. This cost estimate should also be
included in section 5.6.7.
The estimates will be revised to include habitat mitigation costs. Please see response to
comment T3, above.
Page 9
-------
T45. Page 6-2, Section 6.2, Second Paragraph. This paragraph states that, "With appropriate
monitoring and maintenance, capping provides long-term isolation of contaminants."
Before it can be concluded that the preferred alternatives meets the SARA mandate for
permanence, the Trustees believe that specific commitments to address predicted
recontamination of the cap need to be included, above and beyond standard provisions for
long-term monitoring and maintenance.
See Section 11 (Monitoring) of the Responsiveness Summary.
T46. Page 6-3, Section 6.4, Last Paragraph. This paragraph states that the long-term
effectiveness of the cap is "uncertain due to static stability issues." This section should
be expanded to address the potential of recontamination through groundwater migration.
According to the model results presented on page 1-15, the capped sediment areas are
predicted to exceed the 2LAET after 10 years. Does the long-term monitoring and
maintenance envisioned for the preferred alternative include a requirement that
recontaminated areas be remediated again? If so, how? Are there no other source control
activities envisioned that would reduce the likelihood of recontamination?
See Section 8 (Source Control and Potential for Recontamination) of the Responsiveness
Summary.
T47. Table 2-2. Footnote a. Correct the reference to Appendix F. Appendix F does not
include TEQ information.
TEQ information is presented in Appendix K of the RI report.
Page 10
-------
RESPONSES TO THE PSR UPLAND GROUNDWATER RI/FS
-------
-------
ADDENDUM TO THE PSR UPLAND GROUNDWATER RI/FS
RESPONSES TO COMMENTS
This addendum to the PSR Upland Groundwater Remedial Investigation and Feasibility Study
Report (RI/FS) presents comments on the draft RI/FS that were received from the U.S. Army
Corps of Engineers, the Washington Department of Natural Resources, and the Washington
Department of Ecology. EPA responses are also included. Agency comments are provided in a
regular typeface and EPA's responses to those comments are presented in an italicized typeface.
The text of the RI/FS was modified in response to the comments.
U.S. Army Corps of Engineers, Seattle District Comments
In summary, the report concludes the following:
DNAPL at the site has spread laterally along numerous thin coarse-grained soil layers.
Relative saturations have reached residual levels at most locations; therefore most of the
DNAPL migration has already occurred and the remaining DNAPL is mostly immobile
(P-5-9).
Sandy beds, 2 to 3 inches thick, are saturated with DNAPL as far as 200 feet seaward of
the shoreline, but it is not known if the DNAPL layers extend to the mudline (p. 5-9).
Shoreline NAPL seeps have been detected in the Central Shoreline Area and Tank Area 1.
Buried riprap could act as a preferential migration pathway (p. 4-9).
Groundwater modeling indicates that groundwater exiting the site into Elliott bay will be
protective of water quality (p. 9-15). The model did not incorporate biodegradation.
Localized groundwater impacts occur near the thin DNAPL layers (p. 9-6).
The slurry wall prevents migration of LNAPL to Elliott Bay, prevents migration of
DNAPL to Elliott Bay above -25 feet MLLW, and substantially decreases flow of
contaminated groundwater to Elliott Bay above -25 feet MLLW (p. 10-2).
These findings support the comments submitted by this office on the PSR Offshore Unit Phase 2
Technical Memorandum, May 23, 1997:
A-1 Remediation of offshore sediments could be hampered by seepage of NAPL or
contaminated groundwater into the bay. Although the slurry wall should
prevent further NAPL migration above -25 MLLW, some NAPL probably
remains between the wall and the shoreline, and seepage above -25 MLLW
could continue for perhaps several years. Thin layers of DNAPL intersecting
the shoreline and bay floor below -25 MLLW could also recontaminate
remediated sediments.
Response. As mentioned in the Corp's comment, the slurry wall prevents NAPL migration above
-25 MLLW from sources upland of the wall. In addition, the wall has eliminated the main
driving force for DNAPL between the wall and the shoreline. In other words, gravitational
-------
Pacific Sound Resources Record of Decision: Responses to Comments Addendum September 1999
forces associated with the thickness of the DNAPL source body caused seaward migration of
DNAPL in more permeable layers extending from the source area. The slurry wall isolated the
material seaward of the wall from the source area that drove its migration. Without connection
to the source mass, continued migration of stringers located seaward of the slurry wall is
unlikely.
EPA acknowledges that some DNAPL exists between the wall and the shoreline and that there is
some potential for direct impact to sediments from this material. It is important to note that no
NAPL sheens have been observed along the shoreline since construction of the wall. Further,
free-phase DNAPL diminished from 1.8 feet in MW-5S to an unmeasurable thickness the first
year after the containment wall was installed. These observations support EPA's position that
the driving force for migration has been eliminated, that existing NAPL contamination of
sediments is historic, and that any further migration is likely to be very localized and limited in
extent. Monitoring, and maintenance and inspection is required as a part of remedial actions at
the site to ensure that site conditions do not change.
The potential for continued direct NAPL impacts to sediments generally diminishes with depth as
the travel distance between the upland and mudline increases. Again, although the potential for
recontamination of remediated sediments cannot be fully discounted, evidence collected during
the uplands and sediment RI's indicate that direct DNAPL impacts are likely to be very localized
and limited in extent.
A-2 Additional work is needed to establish continuity of geology and extent of
contamination between the Offshore and the Uplands Units. The RI/FS report
contains sufficient uplands boring data'to allow construction of geologic
sections through each of the three offshore deep-core borings, showing
geologic correlations and possible offshore migration paths.
Response. Please see response to the third comment, below.
A-3 As discussed in our comments on May 23, 1997, additional offshore borings
are necessary to allow extension of geologic sections under Elliott Bay. In
addition, alternative methods for locating offshore seepage and evaluating
offshore contaminant flux rates need to be evaluated before proceeding with
the RI.
Response. The idea of developing geologic correlations and possible offshore migration paths,
although ideal, is improbable at this site given the complex stratigraphy described in Section 3 of
the Upland Unit RI/FS. The available data suggest that narrow fingers (or stringers) of DNAPL
are dispersed within the interbedded sand and sandy gravel lenses. The geologic and DNAPL
distribution data, as presented in the site conceptual model (Section 9), do not support the idea
of finding large preferential pathways through which DNAPL migrates to sediments and on
which remedial actions and be focused.
-------
Pacific Sound Resources Record of Decision: Responses to Comments Addendum September 1999
Washington State Department of Natural Resources (DNR) Comments
B-1 Section 1.3.1, Wood Treating Operation, Page 1-5. The ownership of the site as
presented in this text section and summarized in Table 1-2 needs clarification. Although
the majority of state-owned aquatic lands associated with the site are being addressed in the
offshore unit investigations, the filled tidelands in the harbor area which have been included
in the upland investigations are state-owned. This portion of the upland site has been
managed by DNR in the past and is part of the area that will be managed by the Port of
Seattle upon completion of negotiations associated with its port management agreement.
Response. Figure 1-6, Table 1-2, and the first paragraph of Section 1.3.1 were modified to
highlight the fact of DNR ownership for filled tidelands seaward of the Inner Harbor Line.
B-2 Section 4.2.3, DNAPL Distribution and Sources, Seaward Locations, Page 4-6. The
discussion is confusing. Characterizations of several different depths, as well as
presentation of different hypotheses regarding contributing activities, are unclearly
intermingled. It may be more effective to discuss each depth and associated hypotheses to
completion before addressing other depths.
Response: This paragraph was reorganized to improve clarity.
B-3 Other Areas, Page 4-7. The discussion of the origin of DNAPL in the final paragraph is
unclear. The points of consideration associated with each alternative should be more
separate and distinct.
Response: This paragraph was split into two separate paragraphs and edited to improve clarity.
B-4 DNAPL distribution in the Vicinity of Elliott Bay, Page 4-8. The text statement
regarding the removal of substantially all unsaturated-zone source material in the vicinity of
Tank Area 1 does not seem to be consistent with Tank Area 1 as it is illustrated in Figures
4-3 and others; the graphics show residual NAPL at the surface in this area. To the extent
practicable, removal of residual product from the unsaturated zone on state-owned land
would have been preferential to DNR.
Response: Deposits of DNAPL-saturated material were excavated from Tank Area 1 as part of
the Early Actions. Some residual DNAPL-impacted soil remains in this area. Shading in
Figure 4-3 is meant to reflect this condition.
B-5 Figure 5-3, Potential Migration Pathways. I found this diagram confusing and difficult to
interpret.
Response: The figure is based on an ASTM standard and is commonly used in describing site
impacts. The figure was modified slightly to add product storage and piping/distribution of
primary sources.
-------
forth0" ^ MKdJa °5C°ncern' Pa*e 7-1- It would be more accurate to state that no
further act.on, beyond cap maintenance, is expected with respect to contaminated so?..
Response: The narrative was modified as suggested.
B'7 aquatic
c
A » u AC) have been CIted as Potential location-specific
SWork P.' ,7Apn? atuhC PSR Sit£ (reference DNR co« on the DraftS/FS
Study Work Plan and SAP for the PSR Sediment Unit, February 1996) Given that
the uplands addressed in this RI^S are within a harbor area aJd a«- ^erefore state
' especially those spedfic to
^p^e. Table 8-2 Was modified to cite WAC 332-30 as a potential location-specific ARAR.
B^ Table 8-1 Potential Chemical-Specific ARARs at the PSR Site, Page 8-9 The
entry m the Comments column should read: "Groundwater cleanup levelTL
sediments are reported in Table 8-5," rather than Table 8-2. P
Response: The reference was changed from Table 8-2 to Table 8-5.
B-9 Section 10.1.4 , Conformation^ Monitoring Plan, Page 10-5. DNR would like to
contmue o evaluate potential impacts to state-owned laLs at the site bTrtiewbg the
conformation^ momtonng information as it becomes available. In addLniSer issues
regarding sources to the marine environment are identified during the offshore
investigations, we would like the opportunity to evaluate this new Information.
Department of Ecol°^ Northwest Regional Office
General Comments
'
s^
-------
Pacific Sound Resources Record of Decision: Responses to Comments Addendum September 1999
2. It also appears that NAPL migration and groundwater impacts may be greater along the
western shoreline (RW-1 to MW-3) than in the areas to the north (where most of the
modeling effort and text discussion is focused). The potential for surface water impacts from
NAPL and dissolved groundwater constituents in this area needs to be more clearly and
directly discussed. The model needs to be adjusted to place the source term at the shoreline
in areas with residual NAPL saturation (e.g., areas where seeps have been observed).
Ecology will withhold judgement on the need for further source control in these shoreline
areas until these comments and modifications have been addressed.
Response: The text was revised to provide additional clarity on these issues. See responses to
the relevant specific comments below.
Specific Comments
C-1 Page 2-17, first paragraph. How was it determined that 50 percent fluorescence intensity
corresponds to free-phase DNAPL? Especially since free NAPL samples and not soil
samples were used to calibrate the method. Ecology does not have a copy of the
completion report to review the referenced discussion.
Response: A copy of the referenced Completion report was submitted to Ecology and other
relevant agencies. The assumption of 50 percent fluorescence intensity as an indicator of free-
phase DNAPL is based on the technology supplier's experience. Recovery well data showed that
50 percent intensity is a conservative assumption of free-phase DNAPL (i.e., 50 percent intensity
did not result in significant DNAPL collection).
C-2 Page 2-17, fourth paragraph. Why was DNAPL not recovered from RW-1D, in which 10
to 15 feet of product accumulated? Since this is a shoreline well, this would seem to be an
area of concern. Same question on page 2-19, Analysis of DNAPL Samples, second
paragraph.
Response: Monitoring Well RW-ID was installed at the site in August of 1996. The DNAPL
recovery testing described on page 2-17 occurred during the first half of 1996 (i.e., before
installation of RW-ID). Well RW-ID was one of several wells from which routine DNAPL
removal began in August of 1996 and is ongoing. Refer to Section 4.3.1 for updated removal
volumes and other relevant information.
C-3 Page 3-17, second paragraph. The hypotheses that DO is low in shoreline wells due to
biodegradation seems less likely to Teresa Michelsen than other alternatives. If complete
mixing were occurring between surface water and shallow groundwater twice daily, it does
not seem possible that biodegradation alone could reduce the DO from 7 to less than 2. DO
may be low in shoreline wells due to original concentrations of DO in groundwater and lack
of mixing with seawater. This possibility seems borne out by the discussion of salinity for
Round 3 data, showing that salinity (and DO) in shoreline wells was still similar to that in
inland wells. These data strongly suggest that, prior to wall installation, there was not
significant mixing between migrating groundwater and surface waters in the shallow
nearshore areas of the site. Conditions predicted by the model for post-wall installation
-------
Pacific Sound Resources Record of Decision: Responses to Comments Addendum September 1999
will need to be verified by an increase in DO and salinity in the final round of groundwater
monitoring.
Response: The concept of tidal mixing and the effects of such mixing on groundwater chemistry
are central to the subsequent fate and transport modeling presented later in the report
(Section 9). Therefore, a clear and thorough treatment of tidal mixing, which was absent from
the original narrative, is needed in the latter portion of Section 3. Section 3.4.7 is now divided
into two subsections entitled "Groundwater Flow" and "Tidal Mixing, " the latter of which is
new material.
The conceptual model of tidal mixing at PSR is not inconsistent with the salinity and DO data
presented earlier in Section 3. The zone where most of the tidal mixing occurs is very close to
the mudline and is difficult to measure. The shoreline monitoring wells are, for the most part,
completed further upland where most of the mixing is due to dispersion of marine water into the
aquifer. This is a slow process and changes towards a new geochemical distribution will occur
slowly over time in response to construction of the containment wall. Consequently, existing
data on DO, salinity and other parameters, obtained from the shoreline wells are not good
indicators of the effects of tidal mixing.
C-4 Page 3-24, last paragraph. It is not clear to Ecology that all of the water flowing in during
a tidal cycle actually mixes with the groundwater flowing out (the surface water may simply
"bank" above the groundwater table and flow out again on a low tide). If full mixing
occurred, the DO and salinity anomalies identified in the previous comment would not
exist. If complete mixing were occurring every tidal cycle, 6 months should have been
plenty of time for the surface water outside the wall to equilibrate. Furthermore, there
should have been just as much mixing previous to installation of the wall, and there should
not have been a need for "equilibration;" the water in the surface wells would already have
been similar to marine water (especially at 12,000:1 dilution).
The model used may predict changes in head very accurately without indicating whether
mixing is actually occurring. The model should determine the values of salinity and DO
that would be expected as a result of such mixing and, if not verified by site monitoring
data, the mixing predicted by the model should be adjusted accordingly. Since this is the
least well-understood process modeled, only mixing that can actually be verified based on
site data should be used in predicting groundwater concentrations at the point of discharge.
A final round of monitoring results should be conducted well after installation of the site
cap to accurately reflect post-upland cleanup conditions and conduct the final evaluation of
source control.
Response. Please see response to comment on Page 3-17, second paragraph, above.
C-5 Page 4-4, DNAPL occurrence. The text minimizes the estimate that there is over 500 tons
of DNAPL outside the containment wall in the shallow soil layers (an unknown amount of
which is mobile). Plans should be developed to manage, pump, or contain this DNAPL,
particularly along the central (western) shoreline near the old process area, and possibly in
other areas (north-northwest of Tank Farm 1).
-------
1
Pacific Sound Resources Record of Decision: Responses to Comments Addendum September 1999
Response: The text of this and subsequent portions of Section 4 describe estimated volumes and
the distribution of DNAPL at the site based on interpretation of soil boring data, ROSTdata, and
DNAPL observations in completed wells. These interpretations and the subsequent estimates are
subject to uncertainty-r-a common feature of such estimates at all DNAPL sites.
The comment that "...plans should be developed to manage, pump or contain DNAPL near the
shoreline... " is acknowledged by EPA as an appropriate consideration for any DNAPL site.
However, Section 4 is devoted to presentation of the nature and extent of contamination.
Discussion of remedial objectives, a site conceptual model, and cleanup options are covered in
Sections 8, 9 and 10 of the report. In particular, Section 10 describes DNAPL monitoring and
removal as an element of compliance monitoring.
C-6 Figure 4-6. Since there are no data waterward of the impacted wells along the shoreline,
there is no evidence one way or the other whether free-phase NAPL is reaching the water in
this western shoreline area. Question marks or some other method of noting uncertainties
in the shoreward boundaries should be added to the figure. The proximity of impacted
wells to the shoreline in this area suggests it is highly likely that impacts are reaching
surface water.
Response: The figure was revised. Impacts to surface water are addressed in Section 9.
C-7 Figure 4-12. It seems unlikely that the outmost contours would parallel the western
shoreline at 60 to 100 feet in depth. Where there is no available data to predict the actual
extent of contamination, use questions marks or other notation to show uncertainty in the
boundaries.
Response: The figure was revised.
C-8 Page 5-8, last paragraph. The statement earlier on this page that "there are no pools of
DNAPL" may not be true in the vicinity of RW-l, based on the accumulation of DNAPL
seen hi that well. The occurrence of the sandy/gravelly lenses in this area, and along the
western shoreline in general, needs to be better discussed, since it appears this is the one
potential for DNAPL to be reaching the shoreline in quantity. This should also be
highlighted in Section 5.4.2.
Response: Page 4-7 in Section 4.2.3 contains a detailed discussion of subsurface conditions and
release scenarios that could explain DNAPL accumulations at depth in the west-central
shoreline area (i.e., near RW-ID). Reference to the discussion of DNAPL presence at depth
near RW-l was added to the last paragraph of page 5-8.
C-9 Page 5-10, second paragraph. Based on the comments above regarding tidal mixing, we
suggest deleting the fifth sentence until it can be confirmed by groundwater monitoring
results.
-------
Pacific Sound Resources Record of Decision: Responses to Comments Addendum September 1999
Response: Clarifications to the tidal mixing discussion in Section 3.4.7 describe the nature of
mixing (both bulk and dispersive) that occurs as a result of tidal cycling. The groundwater
modeling and conceptual hydrodynamic modeling support the conclusion that dissolved-phase
contamination in groundwater strongly attenuates on approach to the shoreline. No change was
made to the text in Section 5.
C-10 Page 5-10, last paragraph. Along the western shoreline near the process area, it appears
that there is sufficient free-phase and residual NAPL in soils right at the shoreline that
little attenuation, retardation, or degradation would occur before .groundwater reaches
surface water.
Response: EPA acknowledges the western shoreline near the former process area poses the
greatest potential risk of DNAPL impacts to sediment, groundwater, and surface water quality.
The presence and possible remedial measures for any DNAPL located at the mudline is
inherently a sediment issue, whereas the DNAPL source and any consideration of source control
measures is an uplands issue. EPA contends that the likelihood of significant continued DNAPL
movement towards the mudline is slim and that aggressive source removal measures near the
former process area are not beneficial. Note: this is referred to in the Marine Sediments Unit RI
as the intermediate groundwater discharge zone, and will be monitored carefully after
remediation to ensure the remedy remains protective.
C-11 Page 7-1, second paragraph. Based on the conceptual site model shown in Figure 5-3
and data presented in the RI, the possibility exists that DNAPL along the western shoreline
is reaching surface waters, and the possibility also exists that DNAPL in soils outside the
containment wall is affecting groundwater quality near the shoreline. The medium of
concern is stated as "groundwater," however, it should be clarified that NAPL is included.
Response: EPA contends that DNAPL and DNAPL-impacted soil are sources of contamination
to groundwater and that it is confusing to consider DNAPL as a medium of concern. Measures
for DNAPL and groundwater control must nevertheless be considered in the context of meeting
the remedial action objectives set forth in Section 7.2. The first sentence of this paragraph now
reads, "Groundwater is the medium of concern addressed in this FS and DNAPL is the primary
source of contamination to groundwater. "
C-12 Page 8-1, bullets. Zinc levels are also quite high in wells along the western shoreline, and
should be included in the ARARs analysis and in Table 8-5.
Response: Section 8 was revised to include zinc as a constituent of concern. Specifically, a
bullet for zinc was added to the list in Section 8.2, numeric cleanup levels for zinc were added to
Table 8-5, and supporting narrative was added to Section 8.5.
C-13 Page 8-6, Cleanup Levels and Points of Compliance. In addition to numeric cleanup
levels, the state and federal requirement of "no visible sheen" is also an important ARAR
for this site.
-------
1
Pacific Sound Resources Record of Decision: Responses to Comments Addendum September 1999
Response: A note was added to Section 8.5 identifying the requirement for "no visible sheen " on
surface water.
C-14 Page 8-7, partitioning equation. Pentachlorophenol is ionizable in water, and its
sediment cleanup standards are not organic-carbon normalized, nor is its partitioning
expected to be dominated by organic carbon (and hence, KOC). Please explain how the
water values for pentachlorophenol were derived and/or revise them if they were based on
incorrect assumptions.
Response: Ecology was concerned with the method used to calculate PCP partitioning to
sediments in the RI/FS. Specifically, the concern related to the validity of using a Kx value for
predicting aqueous PCP concentrations at the higher pH and ionization strengths of marine
water. In addition, Ecology pointed out that Sediment Management Standard cleanup levels for
PCP are not organic carbon normalized as reported in Table 8-6 of the FS.
EPA contends that using a Kx value to predict aqueous PCP concentrations in marine waters is
appropriate as long as pH and solution ionic strength effects are taken into consideration. The
use of KOC for conditions found at PSR is supported by the literature (Lee et al, 1990). Lee
reported that a modified partitioning relationship to account for pHeffects adequately described
the sorption of PCP to soil. In addition, Lee reported that the degree to which PCP sorbs to
solid matrices increases with increasing solution ionic strength. For pH greater than 7, PCP
sorption to soil increased by a factor of 6 when the ionic strength of a solution varied two orders
of magnitude from 0.01 to 1.4 (seawater has an ionic strength of approximately 0.7).
The KOC value used in the original FS calculations did not account for the elevated pH and ionic
strength of seawater. The EPA has published K^ values for ionizing organics as a function ofpH
in the document entitled "Soil Screening Guidance: User's Guide" (EPA/540/R-96/018). The
reported value for PCP in a solution ofpHS.O, the approximate pH of seawater, is 410 (L/kg).
Using a K^ of 410 L/kg and a sediment organic carbon content of 1 percent results in calculated
pore-water concentrations for protection of sediments at 88 ng/L and 168 pg/Lfor the Sediment
Quality Standards and Screening Levels, respectively. Reducing these concentrations by a factor
of 6 to account for the effects of solution ionic strength still results in concentrations below the
selected PCP cleanup level of 4.9 ng/L (MTCA Method B Surface Water Standards). Therefore,
the conclusions of the RI/FS with respect to PCP do not change based on the above calculations.
Tables 8-5 and 8-6 and the narrative of Section 8.5 were modified per the above discussion.
Table 8-6 was revised to show PCP cleanup levels with the appropriate units (i.e., fig/kg dry
weight of sediment).
C-15 Page 9-4, equations. Again, it is not clear that actual dilution occurs in either zone, to the
extent implied by these equations. Site monitoring data do not support this conclusion.
This whole section needs to be revised accordingly.
Response: The revised conceptual model language for tidal mixing presented in Section 3.4.7
makes clear the nature of both the bulk and dispersive mixing occurring at the site. The
equations, as presented, on page 9-4, are basic mass balance equations and are essentially
-------
Pacific Sound Resources Record of Decision: Responses to Comments Addendum September 1999
independent of the mixing mechanisms involved. EPA believes that existing site monitoring data
do not conflict with the conceptual model of groundwater movement and tidal mixing.
C-16 Page 9-5, third paragraph. The extensive accumulation of NAPL in RW-1I and RW-ID
should be discussed somewhere in this section. Various figures on this page are
inconsistent with those presented earlier in the chapter. Here it is stated that 200 tons of
NAPL are present in Zone A; Figure 4-3 shows 514 tons. 514 tons of DNAPL times 3%
mobile DNAPL is still over 15 tons of free-phase creosote right along the shoreline. This
is not insignificant, though the text uses words such as "minimal" to describe it. The next
paragraph says that free-phase DNAPL is an average of 6% of the total, yet, in Chapter 4, a
figure of 4% was used. Which is correct?
Response: EPA agrees that some of the narrative in this section of the report was confusing.
This is particularly true of the DNAPL percentages cited for the various zones of contamination.
The figures were not in error but were difficult to reconcile with information presented in Figure
9-1 and other portions of the report.
DNAPL masses and percentages cited on Page 9-5 are now more clearly stated and are readily
matched with information presented in Figure 9-1. Figures on dissolved-phase PAH masses were
removed from Figure 9-1 to focus the discussion on DNAPL as was originally intended. Similar
changes were made to Figure 4-3 and page 4-4.
A reference to an earlier section of the report (Section 4.3.1) was added to the narrative on page
9-5. The referenced section describes DNAPL accumulation and removal information for wells
RW-ll. RW-ID, andMW-51.
C-17 Page 9-6, third paragraph. Here, and in many other places in the report, PCP is referred
to as a "DNAPL constituent." It is not. It is another wood treating chemical, and its
presence with creosote is largely coincidental. It ionizes in groundwater, and thus would
not behave much of anything like a heavy DNAPL constituent PAH compound.
Response: EPA recognizes that PCP is not a constituent of creosote, the source of DNAPL at the
site. The first sentence of this paragraph now reads, "Other constituents of concern, such as
dibenzofuran (Figure 4-13) and PCP (Figure 4-14).... " A similar change was made to other
portions of the document where reference is made to PCP as a DNAPL constituent.
C-18 Page 9-6, fourth paragraph. This description of DNAPL outside the wall is occurring
largely in thin stringers is descriptive primarily of the northern areas, and is not really a
good description of what is going on to the west of the process area.
Response: EPA believes that the conceptual model set forth for DNAPL occurrence at the site is
accurate. At the same time, EPA acknowledges that the density or concentration of DNAPL
varies near the shoreline depending on the original source volume and location, distance to the
shoreline, and structure of the complexly interbedded deposits described in Section 3.3.2.
10
-------
Pacific Sound Resources Record of Decision: Responses to Comments Addendum September 1999
The greatest potential for source material to occur near the mudline is in the shallow west-
central shoreline area as discussed in Section 4.2.3. Here, buried riprap may have acted as a
preferential DNAPL migration pathway at shallow depths. Further, any spills from former
product off-loading in. this area would have resulted in a concentrated source of DNAPL very
close to the shoreline.
The RI revealed no evidence of large amounts of free-phase DNAPL in the shallow nearshore
areas of the west-central shoreline. Only modest amounts of DNAPL were removed from MW-5I
and DNAPL removal from MW-5I was negligible. Currently, sheens are not observed at the
shoreline. Therefore, while there are indications ofNAPL occurrence, there is also evidence that
the NAPL mass is immobile and limited in volume.
The last sentence of the paragraph was modified and additional language included as follows.
"... These fingers produce small, localized impacts to groundwater because the volume of free-
phase DNAPL contributing to these fingers is small and because the fingers are limited spatially.
This model of DNAPL contributions to groundwater contamination may not fully explain
conditions along the west-central shoreline. Here, historic spills from product off-loading
operations could have produced direct nearshore impacts. In addition, a former riprap shoreline
that is upland of the existing shoreline could be a preferential route for DNAPL movement.
Currently, there are no product sheens along the shoreline and very limited amounts of DNAPL
have been removed from shallow nearshore wells. "
C-19 Page 9-7, last full paragraph. This may not be a conservative approach in areas where
the bulk of DNAPL transport is though to have occurred in gravelly lenses with higher
hydraulic conductivity than the average aquifer (e.g., west of the process areas).
Response: Data collected during the RI do not suggest the presence of large, continuous'
gravelly-sand lenses at PSR. Instead, the evidence suggests that gravelly-sand layers are
infrequent, discontinuous and unlikely to represent significant preferential migration pathways.
C-20 Page 9-10, Distance to Receptor. As noted above, in some areas DNAPL (both residual
and free) may extend beyond the shoreline monitoring wells to the shoreline. Any areas
where seeps were previously observed will certainly have at least residual saturation of
NAPL that can act as a source to the groundwater, and some free NAPL is predicted by the
report (15+ tons) in these shoreline areas. Anywhere where residual saturation extends to
the shoreline (or where the extent of NAPL has not been fully defined by the
soil/groundwater samples), the source term should be placed at the shoreline (distance =
0), rather than set back the distance from the nearest well to the shoreline. In addition, the
distance to the shoreline should be the shortest distance from a given well to the shoreline,
not the average distance. The point of compliance is the entire mudline, including those
shallower points closest to the well. Seeps have been observed well in-shore of the point
of compliance shown on Figure 9-5, highlighting the need for this requirement.
Response: EPA believes that the fate and transport analysis, including estimates of distance to
receptors, is generally representative of site conditions. Simultaneously, EPA recognizes that
there is some potential for residual DNAPL existing at locations seaward of the shoreline wells.
11
-------
Pacific Sound Resources Record of Decision: Responses to Comments Addendum
September 1999
The greatest risk for such an occurrence is at shallow depths (i.e.. Zone A) along the west-central
shoreline area between boring BH-4 and Wells RW-l. Treating operations were closest to the
shoreline in this area and NAPL sheens were observed on surface water before the containment
wall was installed. No sheens were observed after wall construction.
The sensitivity of the fate and transport assessment to the possibility ofnearshore source
material was evaluated for this revision of the RI/FS. New material describing the sensitivity
evaluation was added to Section 9.2.3. In general, compliance with cleanup levels is still
predicted for most COCs even if NAPL exists at or very close to the mudline. The calculations
assumed the conservative tidal mixing factor of 100. Near the water surface, groundwater
modeling predicts that tidal mixing factors are several fold higher.
The assumed travel distances for the base-case fate and transport modeling were not adjusted as
recommended in Ecology's comment. EPA believes that a 10- to 100-fold increase in the
assumed tidal mixing factor of 100 would be necessary if the shortest distance between shoreline
wells and the mudline were selected as the travel distance. These changes would neither add
value to the overall fate and transport assessment nor change the ultimate conclusions.
C-21 Page 9-13, last paragraph. There are various statements in this section about how long it
would take certain chemicals to migrate to the shoreline. These statements assume that
there is no NAPL shoreward of the monitoring wells that could act as a closer source of
these chemicals to surface water, which is unlikely to be true in some areas.
Response: References to constituent travel times add little value to the discussion of predicted
groundwater quality at the point of compliance. These references were removed from the
narrative and from Tables 9-1, 9-2, and 9-3.
C-22 Page 9-15, last paragraph. These findings need to be reevaluated in light of the above
comments on dilution and on location of the source term. It seems likely that the analysis
holds for most areas. However, in certain areas where DNAPL (free or residual) extends
to the shoreline, or may extend to the shoreline, but existing data are inadequate to
determine this (west of the process area), the model may need to be modified. The
dilution term also needs to be field-tested or verified in some way with site-specific data,
since it drives the outcome of the model. Ecology will withhold judgement on the need for
further source control in these shoreline areas until these comments and modifications
have been addressed.
Response: As discussed above for the comment on Page 9-10, the sensitivity of the fate and
transport assessment to the possibility ofnearshore source material was evaluated for this
revision of the RI/FS. New material describing the sensitivity evaluation was added to Section
y*j*tj*
The tidal mixing factors presented in this section of the RI/FS were derived from modeling that
was calibrated with site-specific data. As such, EPA does not believe that further verification or
field-testing of tidal mixing is necessary.
12
-------
Pacific Sound Resources Record of Decision: Responses to Comments Addendum September 1999
C-23 Chapter 10. Comments will be provided on this chapter following modifications to
address the above comments.
Response: Comment noted.
13
-------
-------
ATTACHMENT 1
REVISED RISK CALCULATIONS
-------
-------
Pacific Sound Resources Record of DecisionMarine Sediments Unit
Residual Risks from Reasonable Maximum Exposure Fish and Shellfish Consumption
Chemical
RTDo (mg/kg-
day)
Polycyclic Aromatic Hydrocarbons
Benzofg .h.i)perylene
Phenanlhrene
Pyrene
Total B(a)P equivalent
Benzo(a)anthr3ccne
Chrysene
Benzo(b)fluoranthene
Bemolkifluoranthcnt
Bemo(a)pyrcne
lndeno(1, 2. 3-cdjpynene
Dibemfa, h)anlhracene
Polychlorlnated Blphtnylf
Total PCB
Dlo«lns/Fur>ni
Total 2.3.7.8-TCDD(Equlv)
TOTAL PCB RISKS
TOTAL DIOXIN RISKS
TOTAL RISKS
TOTAL RISKS W/OUT PCBS
3 OOE-02
2.00E-05
CSFo (kg-
day/mg)
7.30E+00
7.30E-01
7.30E-03
7.30E-01
7 30E-02
7 30E+00
730E-01
7306*00
2.00E»00
1.56E»05
Residual risk following cleanup
Residual Concentrations
(ug"
-------
-------
ATTACHMENT 2
GEOTECHNICAL DATA FROM THREE BORINGS
EB-14
EB-16
EB-114
-------
-------
1
LETTER OF TRANSMITTAL
TECHNOLOGY INC
SPECIALIZING IN PHYSICAL SOCt. TESTING
TO:
ATTENTION:
SUBJECT:
RE:
Roy F. Weston, Inc.
700 Fifth Avenue, Suite 5700
Seattle. WA 98104
Larry Vanslow
PSR
Lab Servies Agreement No. LL-2373-G6
Work Order No. 04000-027-001-2031-01
Sample ID No.'s EB-14, EB-114 and EB16
Date: January 27,1997
Job No.: J-1014
We are sending the following items:
Date
-20-97
-20-97
-20-97
-20-97
-20-97
-20-97
Copies
2
2
2
2
2
1
Description
Friaxial Shear UU, CU and QU (Figures 1 through 16) w/summary tables
Consolidation (4 Plots)
Werberg Limits (1 Plasticity Chart)
3article Size Distributions (6 Plots)
Case Narrative
Copy of invoice No. 1409
These are transmitted for your use,
Remarks: Samples were tested in general accordance with ASTM D-422, D-4318, D-854. D2850.
D-4767, D-2166. D-2974, D-2453 and general laboratory procedures. Please call if you have any
questions regarding this submrttal or presentation of the data. Thank you.
Best Regards,
SOIL TECHNOLOGY, INC.
Richard G. Sheets,
Vice President
JAN 2 9 837
-------
JOOO
«
0- 2000
in
V)
. deg
TAN d
* ,
...
. . _^-
-
-,
\ ' "
....
t
- .
,
....
..:;..
... ...
.....
y^1^ *^
s ~^. / \
/ I I I
10OO 2OOO 300O 4OOO 5OOO 6OOO
Normal Stress, psf
- -
-
. . .
...
/
. J.,.^
&
' ~ ' S
/
jS
JF
'/X-^
.
-
s' ' '
^-r-
s.
/
...... ..
-
S
- -
^^--*"^
' r-
....
. .
5 5 1O 15 2O
Ax ia 1 St ra i n , %
TYPE OF TEST:
Unconsol idated Undrained
SAMPLE TYPE: She by Tube
DESCRIPTION: Silt at top. then
sandy si t. then si t bottom
SPECIFIC GRAVITY- 2.69
REMARKS; Sample 1 O.2-0.7'
Sample 2 O.8-T.3'
Sample 3 2.5-3.0'
Fig NO , ; 1
SAMPLE NO. : 1 2 3
\
_i r
i5 \
H >
5 ;
^ <
j
~~
<
WATER CONTENT , % 49 . 9 46 . 2 40 . 4
3RY DENSITY, pcf 69.8 73.7 78.2
SATURATION. % 95.7 97.4 94.6
*/OID RATIO 1 . 4O4 1 . 278 1 . 1 49
3IAMETER, in 2.83 2.88 2.84
^IGHT. in 6.05 6.03 6.03
WATER CONTENT . % 48 . 8 45 . 1 40 . 0
3RY DENSITY, pcf 69.8 73.7 78.2
SATURATION. % 93.5 95. O 93.6
VOID. RATIO 1.4O4 1.278 1.149
DIAMETER, in 2.83 2.88 2.84
HEIGHT, in 6.05 6.03 6.03
Strain rate, in/mi n o.oeoo o.oeoo o..oeoo
BACK PRESSURE, psf O 0 O
CELL PRESSURE, psf 288O 720 504O
FAIL. STRESS, psf 275 458 ("6315^
ULT. STRESS, psf 275 458 635
-------
Roy F. Weston
Puget Sound Resources
Consolidation Test Results
Stress Tons/ft5
o.oooc
0.050C
0.1 OOC
1
CO
Is
0.1500
0.2000
0.2500
0.
)
) -
-
-
01
-
0.1 1 10
K
0.01
0.00 + , ,
mO.50 -
-£1.00 -
>1.50 -
o
2.00
: ^
p^
^
k
s
N
X
X
\
"\
«-,
\
\
^k
\
"" -.
s,
^,
\
\
\
\
r^^^^
's
\
\
\
^
,
~
*
--
;
i
1
|
1
1
°-1 1 10
H3-
~c:u- ~
n
_1
--,
Stress Tons/ft*
*~ V| _n
n
Number
EB-14
Number
0-3'
ft
1.3-1.5'
Moisture Content %
Before
57
After
48
Atterberg Limits
LL
33
PL
31
PI
2
Wet Density
pcf
Description
Soil Technology, Inc.
J-1014
-------
Roy F. Weston
Puget Sound Resources
Consol Summary
Job#
Exploration #
Sample ID #
Sample Depth {ft)
Type of Test
Date
Test by
Initial Length (in xKT1)
Area (ft**2)
J-1014
EB-14
0-3'
1.3-1.5'
CONSOL
1/7/97
HB
10000
0.03409
dO
2
20
81
190.0
364.0
602.0
945.0
1340.0
1780.0
2118.0
2068.0
1960.0
d90
13
70
170
336.0
563.0
880.0
1230.0
1660.0
2102.0
2090.0
1990.0
1820.0
d100
14.2
75.6
179.9
352.2
585.1
910.9
1261.7
1695.6
2137.8
2086.9
1981.0
1804.4
df
16
77
180
357.0
590.0
927.0
1275.0
1710.0
2148.0
2085.0
1970.0
1802.0
190
1.3
3
3
3.2
2
2
1.15
1.1
1
0.5
0.8
4
I
9991.0
9951.5
9869.5
9726.5
9523.0
9235.5
8890.0
8475.0
8036.0
7898.5
7981.0
8119.0
Cv
ffVday
1.63
0.70
0.69
0.63
0.96
0.90
1.46
1.38
1.37
2.65
1.69
0.35
Load
tsf
0.0156
0.03125
0.0625
0.125
0.25
0.5
1
2
4
1
0.25
0.0625
Strain
Ratio
0.0016
0.0077
0.0180
0.0357
0.0590
0.0927
0.1275
0.1710
-0.2148
0.2085
0.1970
0.1802
Soil Technology, Inc.
J-1014
-------
a.
LL
z
LL
H-
U
a
cr
ai
O.
o
100
90
80
70
60
50
40
30
20
10
0
PARTICLE SIZE DISTRIBUTION TEST REPORT
s
s ssSsl'l o s o o 8 S 8
o .i ,. a S 5 j ; K IS558
i U
t
i
i
! !
.
i
;
200 100 10
% COBBLES
SIEVE
nchej
««
3/8"
^xr
Deo o
D30 0
°10 0
^>
Y
\
\
,
\
M
^
S
tw Q^
GRAIN SIZE - mm
%SILT
57
SIEVE
numbflr
tin
#4
#10
#20
#40
#60
#140
#200
O Source: EB140-3'
SOIL TECHNOLOGY, INC.
%CLAY
6
PERCENT FINER
O
too
100
100
too
99
81
63
uses
ML
-*
k_
^
;
-------
9OOO
tfl
0. 6000
in
V
tn
\_
g 30OO
c.
t/i
O
c
900O
7500
£ 600O
(3
S 450O
(Jn
o 300O
0
| 1500
O
(
RESULTS
C. psf
4> . cleg
TAN ***~
T ' ' *
s
f
'
..:....__..
^-^
. , : ...
S*- '
- -
......
*~^~
...
3 5 10 15 2O
Ax ia I St ra i n , %
TYPE OF TEST:
Unconsol ! da ted Undrained
SAMPLE TYPE: She by Tube
DESCRIPTION: Gray silty sand
SPECIFIC GRAVITY= 2.64
REMARKS; Sample 1 4.3-4.8'
Sample 2 4. 8-5. 3 '
Sample 3 5.5-6.0'
Fig No 2
SAMPLE NO. : \ 2 3
a
§
-
ii
^
WATER CONTENT. 75 35.5 33.6 31.9
DRY DENSITY, pcf 84.9 86.8 89.6
SATURATION. % 99.7 98.5 10O. 3
VOID RATIO 0.940 0.90O 0.839
DIAMETER., in 2.86 2.84 2.80
^IGHT. in 6.04 6.04 5.99
WATER CONTENT .7. 34.8 32.8 31.6
DRY DENSITY, pcf 84.9 86.8 89.6
SATURATION. % 97.6 96.3 99.3
VOID RATIO 0 . 940 0 . 9OO 0 . 839
DIAMETER, in 2.86 2.84 2.80
HEIGHT, in 6.O4 6.O4 5.99
Strain rate, in/min o.oeoo o.oeoo o.oeoo
BACK PRESSURE, psf 0 O O
CELL PRESSURE, psf 1 44O 432O 720O
FAIL. STRESS, psf 1551 5554 7693
ULT. STRESS, psf 1551 5554 7693
<7, FAILURE, psf 2991 9874 14893
<73 FAILURE, psf 144O 4320 72OC
CLIENT: Roy F. Weston
PROJECT: Puget Sound Resources
i
SAMPLE LOCATION: EB-14 3 . O-6 . 0
PROJ. NO.: J-1O14 DATE: 1/8/97
TRIAXIAL SHEAR TEST REPORT
SOIL TECHNOLOGY, INC.
-------
Roy F. Weston
Puget Sound Resources
Consolidation Test Results
Stress Tons/ft2
1
100
Exploration Sample
Number | Number
EB-14
Moisture Content % | Atterberg Limits
Soil Technology, Inc.
J-1014
-------
Roy F. Weston
Puget Sound Resources
Consol Summary
Job#
Exploration #
Sample ID #
Sample Depth (ft)
Type of Test
Date
Test by
Initial Length (in x 10^
Area (ft**2)
J-1014
EB-114
0-3'
1.8-2.0'
CONSOL
1/8/97
HB/RS
10000
0.03409
dO
3
45
114
275.0
470.0
907.0
1335.0
1740.0
2205.0
2626.5
2592.0
2496.0
d90
39
108
254
425.0
859.0
1280.5
1697.5
2156.0
2563.0
2607.5
2518.0
2402.0
d100
43.0
115.0
269.6
441.7
902.2
1322.0
1737.8
2202.2
2602.8
2605.4
2509.8
2391.6
df
44
115
270
470.0
903.0
1330.0
1740.0
2205.0
2633.0
2601.0
2500.0
2390.0
t90
27
23
23
12.5
20
15
8
6
3
0.6
3.5
14
I
9976.5
9920.0
9808.0
9627.5
9313.5
8881.5
8462.5
8027.5
7581.0
7386.3
7454.0
7557.0
Cv
frVdav
0.08
0.09
0.09
0.16
0.09
0.11
0.19
0.23
0.41
1.93
0.34
0.09
Load
tsf
0.01563
0.03125
0.0625
0.125
0.25
0.5
1
2
4
1
0.25
0.0625
Strain
Ratio
0.0022
0.0083
0.0227
0.0414
0.0836
0.1249
0.1641
0.2081
0.2534
0.2520
0.2434
0.2390
Soil Technology, Inc.
J-1014
-------
Roy F. Weston
Puget Sound Resources
Consol Summary
Strain
Ratio
3.00Q4
0.0014
0.0043
J-1014
EB-14
i
3-6'
5.3-5.5
CONSOL
1/8/97
!!
HB
10000
). 03409
14
43
85.0
144.0
22.0
21.0
455.0
633.0
845.0
1109.0
1063.0
004.0
929.0
875.0
33
-""«
3.Q
130.0
202.0
298.0
425.0
40.8
»«
7Q.7
41.1
217.6
318.0
452.8
625.2
9962.0
99210
9863.0
9788.0
9690.5
9560.0
392.0
9187.5
8924.5
934.8
8991.5
9058.5
9110.0
0.0144
0.0222
0.032
0.0455
0.0633
0.0845
X1109
0.1063
0.1004
0.0929
.0875
621.0
837.0
1093.0
065.0
004
933
885
80.0
042.0
1067.5
1013
954
905
1098.7
064.7
003.C
930.7
882
Soil Technology, Inc.
J-1014
-------
PARTICLE SIZE DISTRIBUTION TEST REPORT
i £ ! 5 X 5 S z 2 8 I 1 I I !
100
90
80
70
] 60
Z 50
11
3
-------
5000
H-
o. 4000
in
, deg 37.8
TAN ,
. . .^
s-
r\ -70
v^ . v O
^ /_
' f
*
' «
f : - -
..../
1
's
/'
s
s- -
~^-
s
S
^~^
s
V '
\
. \
-\
/ ....
's*
' S ...
s
^\
\
\
"\
t -
) 2OOO 4000 6000 8000 1 0000 1 2000
Total Normal Stress, psf
£f feet i ve Norma 1 Stress.psf
/
/
/
I
"
s/
. . .
/^
....
r~
.
. . .
-
5 10 15 20
Ax i a 1 S t ra i n , %
TYPE OF TEST:
CU with Pore Pressures
SAMPLE TYPE: Shelby Tube
DESCRIPTION: Silt with sand
LL= .36 PL= 54 PI= 2
SPECIFIC GRAVITY= 2 . 66
REMARKS: Samole Depth O.S-1.31
Fig. No 3
SAMPLE NO. : ]
WATER CONTENT. % 48.3
^ DRY DENSITY, pcf 73.7
H SATURATION, % 102.5
H VOID RATIO 1 .253
* DIAMETER . i' n 2.83
HEIGHT, in 5.95
WATER CONTENT. % 38.5
^ DRY DENSZTY, pcf 85.7
Ld SATURATION . % 1 09 . 3
*" VOID RATIO O.937
% DIAMETER, in 2.67
HEIGHT, in 5.76
Strc
BACK
CELL
FAIL
TO
TO
O) F>
Cj F/
in rate, in/min Q.OOJO
PRESSURE, psf 7200
. PRESSURE, psf 10O8O
. STRESS, psf 4511
TAL PORE PR., psf 8654
STRESS, psf 451 l
TAL PORE PR., psf 8654
MLURE. psf 5937
MLURE .psf 1 426
CLIENT: Roy F. Weston i
PROJECT. Puget So-jnd "-^sources
SAMPLE LOCATION: EB- 1 6 O-3'
PROJ . NO. J-IO 4 DATE: 12/18/96
TPIAXIAL SHEAR TEST REPORT
SOIL TECHNOLOGY, INC.
-------
n r -o O
- o -i -
- n o -
- It 3
- n r>
PI 0 "
CO 3
- 73
<7, t) O
O Hi C <
CD CD uO
i n> "n
a
i/) 5
0 (6
c ui
i a o
O. 3
TJ ' -0
o y
._ o
a, c
z "
o
<_
i
o
-^
...
UJ
7
O
f.
q, psf Total Pore Pressure
Deviotor Stress
psf
o K M A en en
2 o o o o o
.-, o S O O 0 O
^ 0 0 0 0 0 0 0 0 0
rr
H1
U1
T)
0
/-* o
u) o.
H
O
-
~ S
o
o
m
~" ' ijt
fli O
rr K) O
0)
1
I
0
n o
13 O
a
+
o
o
o
01
o
o
\
\
\
.\
\
\
\
\
\
\
\
X
x
r " -~ "
t , 1
\
\'
/ . t -
\
^
/ ^ S ^
0
3
8 9 0
II II II _
-i T
o 2
o £
~ w
n
o 01 M n 5
O -* "* r*
m yi i. 5
Co O ft
t> 0
a vi t
£>*-
*T~^
- \
V
o
M
10
c3
!
,
(
Total Pore Pressure
*
0 to A
S 00
0 00
o 0 o o o
u
!
IO > Ol CD
o o o o
o o o o
o o o o o o
0
N)
o
S!
**
o
to
Q
1
\
\
\
\
A
\
psf
01 m o
0 0 O
o o o
0 0 O
^
O W ^
2 oo
2 oo
o o o o o
^
0
*'
o
«
w
o
\ ~"
1
1
1
1
1
1
1
O) CD O
0 0 0
O o O
O O O
K)
-------
90Q
«
a 6OO
«
«
41
\_
*j
V)
»_
S 300
c
c/1
0
c
1200
1000
m aoo
6OO
i.
u 7OO
o
1
TOTAL EFFECTIVE ' ' - - - .
c , psf o .'';-
f, aeg 41.3
TAN
. . .
' s
r ~
. ? . ..
S . .: .
'
r
/ -
| 0.88
f
i>
/
-£. L
f
~ 1
. I
/
s
t
r ' "
300
^^
....
s
f. .
s
s
t
....
f
6OO
Total »>
Ef feet i ve
.
....
0 .5 10 15 2O
Axial Strain, Z
TYPE OF TEST:
CU with Pore Pressures
SAMPLE TYPE : She 1 by Tube
DESCRIPTION : Silt with sand
LL= 42 PL= 32 PI= 10
SPECIFIC GRAVITY= 2.51
REMARKS: Sample Depth 1.3-1 8'
F 1 a No . 5
...
; ; ; ; ;
». ^, '~r- - > -^%. .
: ^^^.: :::. - :>x '
S *. X
/.:. .\: ..." .:: \ :
/ . . \ \ " ""
\T:...:-,.^. .::...- V
:.:: :::: " ":- :::: : m
-- : i - - \-
" -I'- ! \-\-\ 1 1 1--1
900 1200 T500 1800
Norma 1 Stress, psf
SAMPLE NO. :
WATER CONTENT. % 111.5
^ DRY DENSITY, pcf 42.9
H SATURATION, z 105.4
H VOID RATIO 2.656
g DIAMETER, in 2.88
HEIGHT , i n 6.14
WATER CONTENT. 7. 89.6
£ DRY DENSITY, pcf 50 . 7
UJ SATURATION. 7, 107.4
VOID RATIO 2.093
^ DIAMETER, in 2.73
HEIGHT , i n 5.79
S t ro in rate, i n/m t n o oo3a
BACK PRESSURE, psf 576O
CELL PRESSURE, psf 648O
FAIL. STRESS, psf 1007
TOTAL PORE PR., psf 6221
ULT. STRESS, psf 1O07
TOTAL PORE PR., psf 6221
" C7i FAILURE, psf 1266
Oj FAILURE, psf 259
CLIENT: Roy F-. Weston j!
|
PROJECT: Puget Sound Resources I
SAMPLE LOCATION: E8- 1 6 O-3' .' '
PROJ NO.- J-1O14 - DATE: 12/18/96 :
TRIAXIAL SHEAR TEST REPORT
SOIL TECHNOLOGY. INC.
-------
i
V t
<- s
3 (
M i
t
oc
*^
o
M
a.
o-
7500
60OO
n
' 4500
1 w
a
5 3000
*
3
>
} 1500
0
o
75OO
6000
4500
*-
) o
a
3000
,
1500
0
0
600
300
0
C
jj
/"""
-
-
K 10% 20%
^
S 10% 20%
o
tan o
Peok
Tota
o=
< =
* *
S
f
Strength
1 Effect
O.OO F
33.2 d
O.66
. . . .
,"
sf
eg
-
. ^'
I
\ '
i
\
i
7500
6QOO
450O
3000
15OO
0
O
750O
600O
450O
3OOO
150O
0
O
2
%
4
1 0% 20%
%
.
1 O% 20%
" X
) 3OO 600 900
P. psf
Stress Paths: Tota Effective. --
1200 15OO 1800
- - End +
Client, Roy F, Weston
Project- Puqet Sound Resources
Location, £8-16 O-.3 '
Fil« EB1653 Project No : j-1014 Fig rjo . 6
-------
PARTICLE SIZE DISTRIBUTION TEST REPORT
'1 5 £ i i I I I i I S fill!
1 PERCENT FINER
o
a
100
90
80
70
60
SO
«0
30
20
10
a
i
i
i
i
i
j
'! 1
1
i
I
200 100
% COBBLE
1
I
"T"""
"^"~~^";"
i
H
^-
x
h
-
[
\ \
\\
\
\
i
V
N
I j
\
A
i
;
i
\
>H
v
MM .
i * i i
i
1
y
I
1
1
1
!
i
!
t
10 1 0;1 0.01 0001
GRAIN SIZE -mm
% GRAVEL % SAND % SILT
18 66
17 73
%CLAY
15
10
SIEVE
tenet
size
3/8"
JX^
Deo
030
OIQ
^x^
cc
PERCENT FINER
O
100
a
100
GRAIN SIZE
0.0449
0.0165
0.0024
0.0593
0.0222
0.0048
COEFFICIENTS
2.50
18.56
1.75
12.48
SIEVE PERCENT FINER
number Q
#4 99
#10 97
#20 95
#40 94
#60 92
#140 87
#200 81
D
100
100
100
100
100
95
83
USCS AASHTO
OL
ML
PL LL
32 42
34 36
SOIL DESCRIPTION
O Silt with sand
D Silt with sand
O
D
0 Source: EB 16 0-3' Sample No.: 1 .3-1.8' Elev./Depth.
C Source: EB 16 0-3' Sample No.: 0.8- 1.3' Elev./Depth:
1
j
3OIL TECHNOLOGY, INC.
Client Roy F. Weston '
Project. Puget Sound Resources
Proiect No J-IOI4 Plate 3
-------
150O
CO
a 1000
en
sn
V
in
\_
S 50O
c.
\|\.-. ; :
s. \.
;..- :i: ;:.. \\
v \
V \
: : . . . : : i V .
:\ \ .
. i l . .
i t
DO 200O 250O 3000
o ( St ress . psf
SAMPLE NO. : 1
fi
1
£
LiJ
Ij
WATER CONTENT. % 51 .O
DRY DENSITY, pcf 7O.2
SATURATION, 7. !' 97.8
VOID RATIO 1 . 42O
DIAMETER , i n 2.85
HEIGHT, in 5 . 5O
WATER CONTENT. 7. 41.2
DRY DENSITY, pcf 79.0
SATURATION , % 97.5
VOID RATIO 1 . 1 49
DIAMETER .in 2 . 72
^IGHT, in 5.38
Strain rate, in/min O.QOJO
BACK PRESSURE, psf 576O
CELL PRESSURE, psf 648O
FAIL. STRESS, psf 1337
TOTAL PORE PR., psf 5S46
ULT. STRESS, psf 1792
TOTAL PORE PR., psf 5861
0, FAILURE, psf 247O
Oj FAILURE, psf 634
JCLIENT: Roy F. Weston
SAMPLE LOCATION: EB- 1 6 3-6'
PKUJ . NU . : J-IUI4 DA ft: ll/^O/yo
TRIAXIAL, SHEAR TEST REPORT
SOIL TECHNOLOGY, INC.
-------
Pore Pressure
o
o
H-
1
I
1
1
0) It
>- t
3 4
(ft ..
0 (/
Q- i
4) <
^ <
i£ ':
<
o
+->
o
t-
VI
a
cr
7500
6OOO
n
J 4500
T «
a
j 3000
3
5 1500
0
O
75OO
i
i 4500
1 Ul
a
5 30OO
j
3
>
^ 1500
0
0
8OO
40O
O
(
1
^
7,
3
j--
^
10% 20%
%
-
10% 20%
C
tan c
Peak
Tote
o =
x =
'
,''
3
5t
C 1 i en t : Roy F .
Pro j ec t ; Puge t
Location: EB-16
File EB16CU50
S t reng th
1 Effect
O.OO p
32. 1 c
0.63
, '
-" /
s' 1
\
1
1
i
1
i ve
)Sf
eg
^
-
-;''-'
7500
60OO
4500
3000
15OO
O
0
7500
6000
4500
3000
15OO
O
0
2
»
10% 20%
±J
-
%
-
1 0% 2O%
^-
4OO 800 1 2OO
P. psf
ress Paths: Total Effective-
Wes ton
Sound Resources . .
3-6'
Project No : J-1014
-
i
1
16OO 2OOO 24OO
- - End +
F.i g No . : 8
-------
3OOO
01
o- 2000
tn
tn
t
\_
^
V)
g 1000
t/t
0
C
60OO
5000
\ 4000
tn
S 3000
X.
w
o 2000
o
>
^ 1OOO
0
TOTAL EFFECTIVE
C. psf 0
£, deg 61 O
TAN 4
/
Tt
>l '
/*',
1 SO
/
/
7
V >
/ ''"
,'/'
T ~
/
-
-
.
- - -.,
/
/'
f ' '
/*
/
1 000 2000 30
Total Normal
Ef f ect i ve Norm
. . .
''''/*
. i .
r '
i ,
. .
'^*\
....
^
..... 1
....
-^~
.....
0 5 1O 15 20
Axial Strain, 55
TYPE OF TEST:
CU with Pore Pressures
SAMPLE TYPE: Shelby Tube
DESCRIPTION :
SPECIFIC GRAVITY= 2 . 7
REMARKS Samole Depth 5 5-6. O'
= i ,J >io 9
-.'.'''
^^~ T~-^,^. . . ...
s .: : : :::. ^N ':. . -':
\: -...:..:..: \.. ..
\ ^
^, -: ^
- - . . i y - -
, .... ,,,j... ...,\ ...
"i . ., \ . .
. . .'. i - -
i i
OO 4000 5000 6000
a 1 St ress , psf
5AMPLE NO. : 1
_i
5
i
t,
u
<
WATER CONTENT, % 164.6
DRY DENSITY, pcf 28.2
SATURATION . % 89.2
VOID RATIO 4.981
DIAMETER, In 2.86
HEIGHT, in 6.08
WATER CONTENT . 7. 112.2
DRY DENSITY, pcf 38.5
SATURATION .7. 89 . 8
VOID RATIO 3.373
DIAMETER , i n 2 . 45
HEIGHT in 6.O7
Strain rate, in/min 0.0020
BACK PRESSURE, psf 72OO
CELL PRESSURE, psf 936O
FAIL. STRESS, psf 3418
TOTAL PORE PR., psf 9115
ULf. STRESS, psf 3418
TOTAL PORE PR., psf 9115
Oi FAILURE, psf 3663
03 FAILURE, psf 245
CLIENT: Roy F. Weston
PROJECT: Puget Sound Resources ',
SAMPLE LOCATION: EB-16 3-6'
PROJ . NO.: J-1014 DATE: 11/26/96
TRIAXIAL SHEAR TEST REPORT
SOIL TECHNOLOGY. INC.
-------
Client: Roy F" . Wes ton
Project' Puget Sound Resources
Location. EB-16 3-6'
File. EB1655 Project Mo J-1OI4 Fig No 10
q'_ psf Total Pore PressL
Deviator Stre
psf
- M N) * O
o o o o c
0 0 0 0 C
o o o 0 o o . . o c
(T*
(/I
1)1
TJ
a
r* O
J O
ut o
-1
o
rf
0 ro
O
O
n
O
r, Ul O
1
1
o
n o
3 O
a
Ul
o
o
o
i
\
^
\
N
\
\
\
\
~- - ' ~ "
\
\
\
\
i-r
0
3
Q 9 o
11 " " ^ TJ
r»
o * o n to
_i . »> _
CO O -» 3
vj ro o »
o
ri Tt r»
* . (6 01 -
\
s
\ .
\
\
to
o
°c
o
N)
O
il
re
OQ
o
0
) O
Total Pore Pressi
Dev i at or St r«
psf
O ro *. o
O O O C
o o o c
o 0 o o o c
O)
(sj fk O CD
o o o o
o o o o
3 O O O O
o
ro
o
0
a
*
O
ro
0
V
Y
\'
\
\
jre
1 CD 0
> ° 8
> o . o
) O °
\
"~"
\
>
\
\
1
1
1
1
to * en co o
8 88 8§
3 O O 0 O 0
M
-------
8O.O
"^ 60 .0
a
ui
1/1
W
U)
01
U
O.
1 20. 0
O
. o.o
c
UNCONFINED COMPRESSION TEST
/
1
1
.
^\:
) 4 8 1
Ax i a 1 St ra in , %
SAMPLE NO . :
Unconfined strength, psf
Undrained shear strength, psf
-------
Roy F. Western
Puget Sound Resources
0.0000
0.0500
0.1000
c
fi
w
0.1500
I 0.2000
0.2500
0.01
Consolidation Test Results
Stress Tons/ft2
0.1
X
\
T
\
s
v
10
0.1
10
">;
yl.OO
3/-UU
3 00 -
3
3-
~-o-
C
»-
(
J^
\t
?
J'uu Stress Tons/ft"
Exploration
Number
EB-16
Sample
Number
3-6'
Depth
ft
4.6-4.8
Moisture Content %
Before
171
After
75
Atterberg Limits
LL
41
PL
31
PI
10
Wet Density
pcf
86
Description
Silt
Soil Technology, Inc.
J-1014
-------
Roy F. Weston
Puget Sound Resources
Consol Summary
Job#
Exploration #
Sample ID #
Sample Depth (ft)
Type of Test
Date
Test by
Initial Length (in x 10"*)
Area (ft**2)
1014
EB-16
3-6'
4.6-4.8
CONSOL
11/26/96
HB
10000
0.03409
dO
3
82
290
570.0
960.0
1480.0
1985.0
2308.0
2252.0
2146.0
d90
46
202
464
840.0
1295.0
1816.0
2265.0
2285.0
2168.0
2033.0
d100
50.8
215.3
483.3
870.0
1332.2
1853.3
2296.1
2282.4
2158.7
2020.4
df
50
217
490
883.0
1355.0
1863.0
2314.0
2280.0
2154.0
2012.0
190
5.5
4
2
1.05
1
1
0.5
0.5
1
2
I
9973.5
9850.5
9610.0
9273.5
8842.5
8328.5
7850.5
7706.0
7797.0
7921.0
Cv
fftday
0.38
0.51
0.98
1.74
1.66
1.47
2.61
2.52
1.29
0.67
Load
tsf
0.03125
0.0625
0.125
0.25
0.5
1
2
0.5
0.125
6.03125
Strain
Ratio
0.0028
0.0185
0.0447
0.0827
0.1288
0.1782
0.2215
0.2156
0.2055
0.1931
Soil Technology, Inc.
J-1014
-------
1
PARTICLESIZE
c
S£ S C
- . s 5 O t T
0 « e* - .- ft A Z
\00
SO
80
70
J 60
i 5°
111
J
] 40
Q.
30
20
10
0
j- ;
, '
DISTRIBUTION TEST REPORT
O 0 0 0 8 § 8
200 100 10
% COBBLES
O
% GRAVEL
%SAND
15
SIEVE
indies
size
3/8"
^x^
D6o c
030 o
°10 G
^x^
Cc
<=u
PERCENT FINER
O
100
GRAIN SIZE
.0501
.0217
.0040
COEFFICIENTS
2.38
12.66
V
^.i
i \
[
\
\
\
\
\
~\\
GRAIN SIZE - mm
%SILT
74
%CLAY
11
uses
ML
SIEVE
number
size
#4
#10
#20
#40
#60
#140
#200
0 Source: EB 16 3-6'
SOIL TECHNOLOGY, INC.
PERCENT FINER
O
too
100
100
100
100
95
85
v
X
s
X>
0
0.01 0.001
AASHTO
PL
31
LL
41
SOIL DESCRIPTIOr.
OS
ill
REMARKS:
O
Sample No.: 5.0-5.5' E!ev./Depth:
Client Roy F. Weston
Project. Puget Sound Resources
Protect No.: J-IOI4
Plate 4
-------
PARTICLE SIZE
s s | s s * .
100
90
80
70
I 60
Z 50
u
J
3 _
^
01
GRAIN SIZE - mm
%SILT
15
%CLAY
6
uses
SM
T
-c
r
K>.
*~0
0.01 0.001
AASHTO
PL
LL
SIEVE
number
size
#4
#10
#20
#40
#60
#140
#200
O Source: EB 114 0-3'
SOIL TECHNOLOGY, INC.
PERCENT FINER
O
100
100
100
99
93
35
21
SOIL DESCRIPTION
O Silty sand
REMARKS:
O
Sample No.: 2.5-3.0 Elev7Depth: '
Client: Roy F. Weston
Project: P ..,U Cc-'nd Resources
Proiecl No J-1014
Plate 5
-------
TYPE CF TEST .
(Jnconsol idated Und ro i ned
SAMPLE TYPE : She I by Tube
DESCRIPTION: Too-Clov w/oraanic
.
;ct cpprcx 2.2' becomes ccr.d
SPECIFIC GRAVITY= 2.61
REMARKS: Sample 1 1.3-1.8'
Scrr.p ! s 2 2 C 2 5 '
Sample 3 2.5-3.O'
F i g . No 1 2
il TRIAXIAL SHEAR TEST REPOPT
I! SOIL TECHNOLOGY, INC.
CLIENT: Roy F. Weston ;
PROJECT. P.^gef Sou«d Resources j
i
SAMPLE LOCATION: EB-114 O.O-3.O' |
1
IHKUJ . NU, : J-1U14 DATE: 1/9/y? i
Oj FAILURE, psf 144O 36OO 576O
Deviotor Stress, psf
tn c> 01 O en c
0 0 0 0 0 C
o o o o o o c
" JV : ' ' :::.-:
x vx, - - ..;...
r Ul ' T^S.
" c ' " ... ^ .',..'.. ~
o V
3 : :' ' - ' \
_ ' 'v -
5* ...
.... \. .
.c
C, c -t| o m w
-' r > m > r*
» M r- f> -i
ain rate, in/min o.oeoo o.oeoo o.osoo
K PRESSURE, psf 00 0
.L PRESSURE, psf 144O 3600 5760
i_. STRESS, psf 143 547 7O44
.STRESS, psf 143 547 7O44
FAILURE, psf 1533 4147 1 2SG4
AT TEST
m HO > 5 >
2132^
in 3) O 3J
H H 35 > rn
- m > H 2 n
3 - - Z
0
ro
01 to t0 -^ Co
. ro vt to tn
O 00 t£>
Ul M 0> Oi -^ 0>
01 to O xl >
"^ Ol xj Oi
O 03 -
A - IO .
tn o ^ o CD 01
INITIAL
m H o > 3> >
H > H -H -< H
o z o c m
I m 3) O 3)
H -i 3) > m
- rn > H 2 o
3 O Z H H
- < n
o
to
01 N to 4., 03
to vl IO fll
O CD tO
tn to oo us * to
01 ro o vi 4»
O 03 -
A -* " 03 (O Ol
0^ fo O 10 01
. M tn o to
O 03 (O
tn o -f» o< oo o
1
1>
r'
m
z
O
to
Ol
>
>
) C
o
Ul
o
o
o
01
o
o
o
z
0
I/I ID
~ o
i O
H O
M
u)
T)
Ul
10
8
o
en
8
o
CO
o
o
o
5heor Stress, psf
(M Oi
0 0
0 C'
3 o o
) 1 .'
, , . .
....
y.^
....
>\
:/
,/,,,
Y
/
....
-H
"r
O
o
0
-e-
Q.
CO
-------
9QOO
«
o. 6000
m
t>
g 300O
c
O
c
12000
10000
£ 8000
n
S 6000
in
o 400O
0
>
g 2OOO
O
C
TOTAL EFFECTIVE
C, psf 0
+ . deg 39.4
TAN 5 1O 15 2O
Ax ia 1 St ro i n , %
TYPE CF TEST.
CU with Pore Pressures
SAMPLE TYPE: She 1 by Tube
DESCRIPTION: Silty sand
LL- 43 PL= 3 1 PI= 2
SPECIFIC GRAVITr= 2 . 7
REMARKS. Sample Death 4.9-5.4'
Fia No 13
.'.:'.'.'.'''.'' : \
N." ^'V,
- - A - - - \ -
- - - - - \ - - - - -
\ \
\ \
\ "1
t 1
00 120OO 1500O 18000
al Stress, psf
SAMPLE NO. : I
WATER CONTENT. 7. 43.3
J DRY DENSITY, pcf 76.9
H SATURATION. % 98.0
H VOID RATIO 1 . 193
g DIAMETER, in 2.82
HEIGHT, in 6.10
WATER CONTENT. % 32.4
£ DRY DENSITY, pcf 92.7
u SATURATION. % 1O7.1
*~ VOID RATIO 0.818
^ DIAMETER , i n 2 . 6O
HEIGHT .in 5.92
Strain rate, in/min 0.00*0
BACK PRESSURE, psf 5760
CELL PRESSURE, psf 10800
FAIL. STRESS, psf 9197
TOTAL FORE PR., psf 8150
ULT. STRESS, psf 9197
TOTAL PORE PR., psf 815O
<7l FAILURE, psf 1 1847
O3 FAILURE, psf 2650
CLIENT: Roy F. West on i
. i
PPQ.JECT: Puget So>j"d Resources j
!
SAMPLE LOCATION: EB- 1 1 4 3-6' '
PKUJ . NO.: J-1U14 UATt : ll/^to/yt j
TRIAXIAL SHEAR TEST REPORT
SOIL TECHNOLOGY, INC.
-------
Roy F. Weston
Puget Sound Resources
0.01
0.01
0.00 -
? 0.10 -
Q 0.20 -
£ 0.30
£ 0.40 -
0.50 J
t
Consolidation Test Results
Stress Tons/ft2
Soil Technology, Inc.
J-1014
-------
Client: Roy F. West on
Project- Puqet Sound Resources
Location. £8-114. 3-6'
File- £611-149 Pr0)ecc No : J-101* Fig. No : 14
q> psf Total Pore Pressu
Deviotor Sire
psf
M * M * Ol
8 8 8 . 8 §
o o o noooo
w °
n
n!
U)
HI
T)
to 10
in O
1
0
Q ^
O
0
O
m
-> - a\
0) O
n t> o
rt U> O
iti
i
i
1 CD
m o
3 0
a
4-
0
o
c
c
i o
\
V
\
\
\
\
\
\
/*
V.
\
s \
"\
Peok Strength
Tota 1 Effect i v«
a= 0.00 psf
ex = 32.9 deg
tan ex = O.65
V,
....
'
\
\
- - i
4
to
D
0<
O
M
M
O
re
Oa
O
0
o
Total Pore Pressure
Devigtor Stress
psf
O M * 01 03 0
§00000
o o o o o
0 _ 0 0 0 0 0 0
I S3 it 1 1 n 1 1 1
01
M A °> O"
8888
D0 0 00
;. .
o
£
*w^-^«^^
^-v
\
\
^ "^
1
1
1
1
t
1
. 1
I \
1 \
I
o io > a; oo c
o o o o o c
0 0 0 O 0 C
o^o o o o o o
*
':
i-J
o
M
o
N>
j
1
-------
. deg 37.1
TAN 4 0 . 76
'x
X
X
X
.
. .
X
V
X , .
- 1
i
J
*'* /
x / /.
if
V:
^
x
x
X
X '
2OOO 40OO
Tote! f
Ef r'ect i v<
./
/
i- '
/
/ '"
:':':
) 1O 2U 30 40
Axiat Strain , %
lire, or i c_i i .
Cu wt C h Pore P
SAMPLE TYPE : She
DESCRIPTION: Si 1
LL= 39 PL= .
SPECIFIC GRAVITY
REMARKS Gamp 1 e
Fig fio 1 5
ressures
by Tube
tv sand
50 PI= 9
= 2 . 67
3ecth 5.5-6 OJ
^ . . i
x
.xl ...
X
X .
X
X ......
" . ,; . :; . ' ;
^"^Nx :: .':.'. '.':.. '.': ..'
:::: ::.. ^;:': "::. : . '
\\
n
H
6OOO 8000 1 0000 1 2000
i Normal Stress, psf
SAMPuE NO . : 1
WATER CONTENT. 7. 36.9
^ DRY DENSITY, pcf 81.2
H SATURATION . % 93.7
H VOID RATIO 1 .052
g DIAMETER, in 2.89
HEIGHT, in 6.O7
WATER CONTENT . % 29 . 9
£ DRY DENSITY, pcf 91.0
LJ SATURATION, % 95.8
H VOID RATIO 0.833
£ DIAMETER, in 2.75
HEIGHT, in 5.97
Strain rate, in/min 00040
BACK PRESSURE, psf 72OO
CELL PRESSURE, psf 9360
FAIL. STRESS, psf 59S9
TOTAL PORE PR., psf 7416
ULT. STRESS, pst syey
TOTAL PORE PR., psf 7416
Ot FAILURE, psf 7913
Oj FAILURE, psf 1944
CLIENT: Roy F. Weston j
PROJECT: Puge*. . Sou"d Peso _-<:
-------
n r T> r>
O n
-no--
*& 0 - O
- .
0 (I
C Ul
U 3 i-
i a o
^t o
"^ " n?
° 8
(t E;
" n
ft
2!
o
i
o
4k
vO
0
_
0)
q, psf Total Pore Pressure
Deviator Stress
psf
rl S (0 * 0) CO
2 S o o o o
° S O O 0 0
o ° o oooooo
r*
(D
in
Tl
a -
^» 0
J 0
M °
H
o
r+
Q ix)
- o
o
0
n
-D
rti O
ft T) O
rr U O
(6
1
m o
3 0
a
+
Ul
0
at
O
\
\
\
\.
. \
\
\
\
\
V
/
i
*
t i >
;
\ .
\ - '
\\
xs\
o
9 P o
' H J
" Q
0 ^
l/l
D
o GJ o n .a
0) O -* -T
- o> o «
o
a T> «
(t 01 -
A
: \\
**
»
. : ; ,\
....
.til.
i
' i
\ '-.
\
\
- \
\x
... ..
N
O
to
Q
'"
Total Pore Pressure
Deviator Stress
psf
9 M A O> 00 C
o o o o o o
S o o o o o
ooo o o o o o
Li
i
(0 £ 0> CO
O 0 0 O
o o o o
o o o o o
M
-^
o
ro
-
M
o
NJ
o
^
1
.
\
\
*
.
1
\
V
\
\
\
\
,
1
/
1
1
1
1
"\ -
1
I
;
*
'
;
o M ji a> oo o
o o o o o o
o D a o o o
ooo o o o o o
*
:
O
^
I
o
M
o
w
-------
PARTICLE SIZE DISTRIBUTION TEST REPORT
E
1 « * i ' £ g s * a, J| 1 I 1 « = e
100
90
80
70
J 60
E 5°
LJ
30
20
10
0
i
. i
.
^S
J
t
r
. s=^
i
i
S
i
ir)
"i
i
1 ;
\
\
1
! ;
\ i i
\i
; ^
; 'I
-
1
i
.1
N-,
IP
c
y,
H
;T^,
^
j!1 !
i i
:-;j
, i i
Ml j
!j
i
Nk
Ti
! i
'
.
'
i
^
IE
f"
200 100 10 1 0.1 0.01
GRAIN SIZE - mm
% COBBLES
O
a
% GRAVEL
2
% SAND % SILT
58 36
63 28
%CLAY
4
9
SIEVE
incm*
see
3/8"
^xd
°60
030 (
°ia (
^xC^
cc
PERCENT FINER
O
IOO
a
100
GRAIN SIZE
0.161
).0652
).0t29
0.160
0.0421
0.0055
COEFFICIENTS
2.03
2.47
2.03
29.35
SIEVE
number
size
#4
#10
#20
#40
#60
#140
#200
PERCENT FINER
0
98
98
98
95
77
49
40
a
too
100
98
94
76
46
37
USCS AASHTO
SM
SM
§QIL DESCRIPTION
OJ
iltysand
1
i
1
i
1
3-o^s
PL
31
30
0.001
LL
43
39
Q Silty sand
O
0
0 Source: EB 1 14 3-6' Sample No.: 4.9-5.4' Elev./Oepth:
Q Source: EB 1 14 3-6' Sample No.: 5.5-6.0' Elev./Depth:
jChent Rov F. Weston
SOIL TECHNOLOGY, INC. Pro|ectpugets°lurwjrces
ProiectNo J-1014 Plate
tl
-------
Roy F. Weston
Puget Sound Resources
Table 1: Soil Parameters
Boring Number
EB14
EB14
EB16
EB16
EB16
EB16
EB114
EB114
EB114
Boring Depth
feet
0-3
3-6
0-3
0-3
3-6
3-6
0-3
3-6
3-6
Sample Depth
feet
0.2 - 0.7
4.3-4.8
0.8-1.3
1.3-1.8
4.0 - 4.5
5.0-5.5
1.8-2.0
4.9 - 5.4
5.5 - 6.0
Specific Gravity1
2.69
2.64
2.66
2.51
NA
2.72
2.61
2.70
2.67
Total Volatile
Solids2
%
2.8
2.5
4.0
20.3
39.9
NA
5.1
3.8
2.4
' Specific Gravity determined foOowmg ASTM D-854 methodology.
3 Total Volatile Solids determined following ASTM D-2974 Method C.
NA" Not analyzed.
Soil Technology, Inc.
J-1014
-------
Plasticity Chart
Roy F. Weston
Puget Sound Resources
70
60
50
40
CH
X
-------
1
Roy F. Weston
Puget Sound Resources
Case Narrative
When interpreting results it is necessary to give careful attention to the depths of each sample taken from within
the shelby tube. In some instances the sample type within a tube varied significantly from the top to the
bottom. When Atterberg Limits, specific gravity, grain size and total volatile solids are not reported for each
individual sample, that indicates that the material changed type within the tube and that data was not generated
for each sample type.
-------
ATTACHMENT 3
EDDIE PUMP DEMONSTRATION PERFORMANCE DATA
-------
-------
RESULTS FROM THE EDDY PUMP
DEMONSTRATION AT SANTEE CALIFORNIA
JUNE 21 - JUNE 24,1999
US ACOE WATERWAYS EXPERIMENT STATION
STEVE SCOTT
BACKGROUND
The Eddy Pump dredge was demonstrated in Santee California during the week of
June 21, 1999, at an abandoned 19-acre gravel pit. The dredge pumping plant consists of
a 10-inch Eddy Pump powered by a 400-horsepower motor. The pump is attached to the
dredge frame by a steel ladder, with the discharge line running along the ladder, under the
dredge frame, and out the back of the dredge. The dredge is designed to operate as either
a stationary platform or advance through a cut much like a conventional cutterhead
dredge. A spud carriage is used to advance the dredge forward through the cut. A
traditional dredge ladder is rotated through the cut radius using winches. The Eddy Pump
dredge utilizes powered wheels attached to the pump infrastructure which are assisted by
water pump thrusters to swing the ladder and pump.
SITE CONDITIONS
The sediments in the abandoned gravel pit consisted of a layer of fine silt
overlaying sand. Sediment analysis at the Engineering Research and Design Center
(ERDC) indicated that the sand is a narrowly graded medium sand with a median particle
size of about 0.45 mm and an in-place saturated density of 1.89 g/cm3. The pit also
contained large rocks and scrap metal.
ACQUIRED DATA
During the tests, the following data were logged: pump discharge pressure,
flowrate, percent solids by in situ volume, electric motor amperage, spud advance, depth,
turbidity, and heading. Data were acquired every five seconds.
RESULTS
Data were acquired while the dredge advanced through a cut. The data were
analyzed for dredge productivity and pump efficiency. Figures 1 - 5 depict the slurry
velocity, slurry specific gravity, pump efficiency, dredge production, and turbidity
generated for a 27-minute test. The pump ingested a large piece of scrap metal which
locked up the pump, therefore further testing was halted.
\\FSSEAO 1 \DATA\PRODUCTN\RFW\99-0318.at3
-------
Pump Efficiency -
U> '
ft
a
H
3
fl
f
I
en
T3
n>
CTQ
i
I ;!
Slurry SO
era
GO
JL
o"
o
S
5'
f
i
I
a
Slurry Velocity - ft/s
-------
0.14
0.28
0.42
Time - hrs
Figure 4. Eddy Pump dredge production
Z
J2
'E
0.00
0.14
0.28
0.42
Time - hrs
Figure 5. Turbidity measured just above the pump
During the test, the pump speed was a constant 1200 revolutions per minute. The
discharge pipeline consisted of 55 feet of 10 inch pipe, 320 feet of 8 inch plastic pipe, and
a 28 foot piece of 8 inch pipe used as a discharge manifold for evenly distributing the
slurry in the disposal pit. The digging depth ranged from 20 to 30 feet. The flow rate at
1200 rpm ranged from approximately 3300 gallons per minute (gpm) when pumping
water to approximately 3100 gpm when loaded with slurry. This represents a velocity
range of approximately 13.5-12.5 feet per second in the 10 inch pipeline (Figure 1).
The critical carrying velocity for a medium sand in the 10 inch pipeline is approximately
10 feet per second. The discharge pressure head ranged from 45 to 50 psi (104 - 116 feet
of fresh water) during the test.
The density data (Figure 2) was characteristic of data from nuclear density
gauges. It consists of data spikes that result from slugs of sediment passing through the
gauge measurement field. The average of the data represents the solids delivery to the
disposal site. Because the data record is so short, and the dredge did not advance, the
data will not be analyzed for cycle efficiency or average interval productivity. The
average specific gravity delivered to disposal was approximately 1.15, which represents
17 percent of insitu solids, or 21 percent solids by weight. The maximum average
specific gravity attained during the test was approximately 1.3, which represents 34
percent of insitu solids, or 37 percent solids by weight. This record occurred during the
last 2-5 minutes of the test. Appendix A contains formulas for computing the percent
solids by insitu volume, percent solids by true volume, and percent solids by weight.
-------
1
The average dredge production over the test was approximately 159 cubic yards
per hour. The maximum production was approximately 306 cubic yards per hour. The
average pump efficiency over the test duration was approximately 60'percent.
The turbidity measurement was made just above the pump. The measurements
were in units of Nephelometric Turbidity Units (NTU), which are a measurement of the
scattering of light passing through a column of water. This scattering effect increases as
the particle concentration increases in the water column. This is a qualitative rather than
quantitative method of describing turbidity due to suspended solids. Figure 5 presents the
turbidity data. The data indicates that when the dredge had riot fully engaged the material
(0 - 0.23 hour of the data record), the turbidity was on the average 44 NTU. When the
suction head was engaging the material, the turbidity measurement increase to an average
of 66 NTU (0.23 - 0.45 hour of the data record). This represents an increase of
approximately 50 percent. As you can see from Figure 5, the turbidity scale begins at
about 15 NTU, so it is questionable whether the sensor was calibrated before the test.
Regardless of the calibration, the 50 percent increase in turbidity due to the Eddy Pump
engaging the material is representative. I attribute the turbidity to the very fine layer of
sediments on the gravel pit bed. This can better be quantified in the future if suspended
sediment samples are taken along with the turbidity measurements.
DISCUSSION
The test was of too short duration to draw any conclusions about overall dredge
performance. Data should be taken over numerous dredge advance cycles to evaluate
cycle efficiency as well as dredge productivity. The productivity of an advancing dredge
such as a conventional cutterhead dredge or the Eddy Pump dredge design is dependent
on the solids available to the suction line, not pump performance. Both the Eddy Pump
dredge and a conventional dredge can pump the solids if they are available. The
maximum concentration of saturated sand that can be pumped over a sustained interval is
approximately 50 percent of insitu solids volume (53 percent solids by weight), assuming
a saturated sand density of 2.0 g/cm3. Concentrations as high as 60 percent of insitu
volume (60 percent solids by weight) have been pumped, but not over any appreciable
length of time because of the possibility of plugging the pipe. Attached are density and
production records from submersible centrifugal pumps that were used in sand by-
passing tests (Appendix B). The pumps are manufactured by Toyo and H&H, with
discharge pipe diameters of 10.0 and 8.0 inches respectively. The slurry specific gravity
was measured by both a differential pressure gauge and a density gauge for comparison
purposes. The production and percent solids by weight data are for the density gauge
record. The pumps achieved up to 50 percent solids by weight, but could not sustain it
because of pipe plugging. No hydraulic pumping system can pump saturated sands at
insitu densities (70-80 percent solids by weight).
The cut face that the dredge is working in limits the amount of solids that can be
entrained, as well as the method of dredge advance. The lower the cut face, the more
water that will be entrained into the suction line. The spud carriage is the most efficient
niethod of advance. Conventional spuds on which the dredge pivots during the advance
-------
keep the dredge in the material approximately 50 percent of the time. The spud carriage.
because of its forward movement, is more efficient, and can raise the cycle efficiency to
75 percent These are only approximate cycle efficiencies, and may vary substantially
due to operator expertise. Therefore, the solids delivered to disposal are dependent on
cutface height and on the advance (cycle) efficiency. For example, if the cut face is
substantial (the suction line buried in the material), the maximum average slurry specific
gravity pumped could be 1.4. The slurry specific gravity delivered to disposal is reduced
because of the advance efficiency. Assuming a 75 percent cycle efficiency results in a
slurry specific gravity delivered to disposal of l+(,75*.4) = 1.3. Very rarely is there
sufficient material to obtain the maximum solids flow rate. The cut face height and
terrain will vary, as well as the operator expertise. The suction head will not remain
buried in the sediment 100% of the time. Therefore, the average solids pumped while the
head is engaging sediment will be lower than the maximum possible. The cycle
efficiency will also vary substantially due to operator expertise.
The efficiency of the 10 inch Eddy Pump was only evaluated at one speed (1200
RPM), and resistance (pressure head condition). The efficiency will change as a function
of rotor size, rotor speed, and resistance.
CONCLUSIONS
The productivity of the Eddy Pump dredge can only be properly evaluated over a
lengthy dredging project. Based on my observations, and experience in evaluating
hydraulic dredging production data, I believe that the Eddy Pump dredge can pick up and
transport an average slurry specific gravity of approximately 1.3 (30 percent insitu solids,
40 percent solids by weight) when engaging the cutface. This is assuming an insitu sand
density of 2.0 g/cm3 and the dredge is maintenance dredging (going through the advance
and swing cycle). Assuming a 75 percent cycle efficiency, the slurry specific gravity
delivered to disposal will be further reduced to 1+(.75*.30) = 1.22. This represents 22
percent insitu solids or approximately 29 percent solids by weight. The production at a
1.22 specific gravity and a nominal flow rate of 12.0 ft/s in the 10 inch pipeline would be
192 cubic yards per hour. This assumes an experienced operator. The productivity can
be higher or lower depending on conditions, but overall, I feel that this is what can be
expected in normal maintenance dredging conditions. For hard packed sediments, the
Eddy Pump dredge may not be effective in entraining solids unless some method is used
to break up the sediment.
The solids content of the slurry will vary with the insitu density. Assuming that
the dredge will entrain, on the average, 30 percent of the insitu solids, Table 1 presented
below presents estimated slurry concentrations for sand, silty sand, and silt sediments.
Table 2 presents the amount of water that must be transported to the disposal site per yard
of insitu sediment and per yard of solids only
-------
Sediment
Sand
Silty Sand
Silt
Insitu SG
2X)
- 1.7
1.4
Cutface SG
1.30
1.21
1.12
Delivered SG
1.22
1.16
1.09
% Insitu Vol
22
22
22
% Solids Wt
29
22
13
Table 2. Water delivered to disposal per yard of sediment dredged
Sediment
Sand
Silty Sand
Silt
Delivered SG
1.22
1.16
1.09
Yards of Water
Per Insitu Yard
3.5
3.5
3.5
Yards of Water Per
Yard of Solids Only
6.5
9.0
18.0
Test data for two other Eddy Pump Demonstrations were examined The Eddy
Pump was used to dredge sands at Cresta Reservoir in California and silty sands for Fina
Oil in Texas For the Cresta reservoir work, it was reported by Harrison and Weinrib that
a 10.0 inch diameter Eddy Pump averaged approximately 300 cubic yards per hour This
represents a slurry specific gravity of approximately 1.34 at a velocity of approximately
12.0 ft/s. At the Fma Oil demonstration site, the Eddy Pump was working in silty sands
The average specific gravity pumped was 1.16, with an estimated insitu sediment specific
gravity of 1.6. The scaled slurry density for sand sediments with an insitu specific
gravity of 2.0 g/cm for the Fina test would be approximately 1.27. Table 3 compares the
estimated slurry solids transport to that measured during the Fina and Cresta Reservoir
tests.
Table 3. Estimated and measured average sand slurry solids concentration
Source | Avg Delivered SG I % By Insitu Vnhimp I «
% By Weight
Estimated
1.22
1.34
22.
29.0
Cr
esta Reservoir
Fina Oil
34.0
41.0
1.27
27.0
34.0
Because the three dredge designs that were used for the Santee, Cresta Reservoir
and Fina Oil demonstrations were different, the method of advance probably varied thus
the ability of the pump to pick up and transport the solids may have affected the numo
performance. r v
In a static application, where advance is not a concern, and the suction line of the
pump can be totally embedded in the sediments, the pump can potentially maximize
production (approach 50 percent sand insitu solids) only if the pump can provide the
necessary power to overcome friction losses in the line, and sustain the critical flow
-------
velocity so the solids do not settle out and plug the pipe. Because pump curves are not
available for the Eddy Purnp, this capability cannot be confirmed at this time.
For static applications in viscous materials such as sludges, the Eddy Pump may
be effective. Sludges containing sewage wastes and fine clays can have very high
viscosities and yield stress when found in high concentrations. The yield stress results
from chemical and electrical forces that bind the particles together. When subjected to
agitation, or shearing action, the bonds are broken, and the material becomes easy to
pump. These materials are referred to as shear thinning. The effect of the Eddy Pump
vortex impinging on the material would tend to agitate the surface, breaking the particle
attractions, and thus entraining the sediments. Once subjected to the agitation of the
rotor, and pumped in turbulent flow, the friction losses of these materials becomes
approximately that of water only in the pipe. Additionally, because the fine particles
commonly found in sludges have very low settling velocities, the critical settling velocity
is not a concern, therefore these materials can be pumped significant distances with low
power requirements.
-------
1
APPENDIX A
SLURRY CONCENTRATION CALCULATIONS
Percent Solids By True Volume: This represents the percent solids by volume in the
slurry. This is the solids volume without the pore volume
Cvt = ((SGs - SGw)/(SGm - SGw)) * 100
With SGs = The slurry specific gravity (measured by the density gauge)
SGw = The water specific gravity (1.0 for fresh water, 1.025 for salt water)
SGm = The mineral specific gravity (-2.65 for quartz)
Percent Solids By Insitu Volume: This represents the percent solids by insitu volume in
the slurry. This is the volume of solids plus the pore volume between the sediment
grains.
Cvi = ((SGs - SGw) / (SGi - SGw)) * 100
With SGi = The insitu sediment specific gravity (-2.0 for sand)
Percent Solids By Weight: This represents the percent solids in the slurry by weight.
= ((Cvt*SGm)/(l+((SGm-l)*Cvt)))*IOO
-------
1
APPENDIX B
RESULTS FROM THE TOYO AND H&H SUBMERSIBLE PUMPS
-------
-------
1
Slurry Specific Gravity
TOYO Submersible Pump
Clean Sand Test 1
SG Density Meter
SG Pressure Difference
0.75
Plate B71
-------
1
Test Results TOYO Submersible Pump
Clean Sand Test 1
800 i 1 70
5,0
"r~
<2 o>
OJ 3
OC co
£0.
>» (Q
*
700
600
500
400
300
200
100
0
0
-% Solids By Weight
-Velocity
-Hourly Production Rate
-Booster Pump Pressure
60
10 15 20
Time (min)
Plate B39
-------
1
0.75
Slurry Specific Gravity
TOYO Submersible Pump
Clean Sand Test 2
SG Density Meter
SG Pressure Difference
15
Time (min)
Plate B73
-------
1
1
800
700
F JL 600
aTm 500
ml
EC to
_ M
J5| 400
1ft
o E
££ 300
^
11 2»
100
0
c
"est Results TOYO Submersible Pump
Clean Sand Test 2
% Solids By Weight A/
Velocity /"
Hourly Production Rate V
... Booster Pump Pressure .
J' If L i
- ---.. |
> 5 10 15 20 25 3
Time (min)
°oS8£S8a!
Percent Solid By Weight (%)
Velocity (ft/sec)
Plate B40
-------
R
i
8
fi
0.75
0
Slurry Specific Gravity
H & H Submersible Pump
Clean Sand Test 1
-SG Density Meter
-SG Pressure Difference
10
15
Time (min)
20
25
30
Plate B64
-------
800
Test Results H & H Submersible Pump
Clean Sand Test 1
70
% Solids By Weight
Velocity
Hourly Production Rate
Booster Pump Pressure
10 15 20
Time (min)
Plate B31
-------
1
Slurry Specific Gravity
H & H Submersible Pump
Clean Sand Test 2
^
-SG Density Meter
SG Pressure Difference
15 20
Time (min)
25
30
Plate B65
-------
Test Results H & H Submersible Pump
Clean Sand Test 2
800
700
% SOlids By Weight
Velocity
Hourly Production Rate
... Booster Pump Pressure
0
10 15 20
Time (min)
25
\
70
60
50 g
x:
40
CO
30
20 9>
10
£L
0
30
Plate B32
-------
-------
-------
Reproduced by NTIS
£ o"o
*fc§>
0) fl^£^"»
v ^ 0>O
o o o
T C
> c
o o Q)
£ 0) o
££u
E03
fl) O O
Zo.!2,£
National Technical Information Service
Springfield, VA 22161
77f/s report was printed specifically for your order
from nearly 3 million titles available in our collection.
For economy and efficiency, NTIS does not maintain stock of its vast
collection of technical reports. Rather, most documents are printed for
each order. Documents that are not in electronic format are reproduced
from master archival copies and are the best possible reproductions
available. If you have any questions concerning this document or any
order you have placed with NTIS, please call our Customer Service
Department at (703) 605-6050.
About NTIS
NTIS collects scientific, technical, engineering, and business related
information then organizes, maintains, and disseminates that
information in a variety of formats from microfiche to online services.
The NTIS collection of nearly 3 million titles includes reports describing
research conducted or sponsored by federal agencies and their
contractors; statistical and business information; U.S. military
publications; multimedia/training products; computer software and
electronic databases developed by federal agencies; training tools; and
technical reports prepared by research organizations worldwide.
Approximately 100,000 new titles are added and indexed into the NTIS
collection annually.
For more information about NTIS products and services, call NTIS
at 1-800-553-NTIS (6847) or (703) 605-6000 and request the free
NTIS Products Catalog, PR-827LPG, or visit the NTIS Web site
http://www.ntis.gov.
NTIS
Your indispensable resource for government-sponsored
informationU.S. and worldwide
-------
-------
| |