Puget Sound Estu
ELLIOTT BAY ACTION PROGRAM:
¦¦ V
The Relationship Between Source
Control and Recovery of Contaminated
Sediments in Two Problem Areas
TC-3338-23
FINAL REPORT
June 1988
Prepared for
U.S. Environmental Protection Agency
Region X - Office of Puget Sound
Seattle, Washington
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TC 3338-23
Final Report
ELLIOTT BAY ACTION PROGRAM:
THE RELATIONSHIP BETWEEN SOURCE CONTROL AND RECOVERY
OF CONTAMINATED SEDIMENTS IN TWO PROBLEM AREAS
Prepared by
Tetra Tech, Inc.
for
U.S. Environmental Protection Agency
Region X - Office of Puget Sound
Seattle, WA
June 1988
Tetra Tech, Inc.
11820 Northup Way, Suite 100
Bellevue, Washington 98005
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PREFACE
This document was prepared by Tetra Tech, Inc. for the U.S. Environmen-
tal Protection Agency (EPA) Region X, Office of Puget Sound under the
Elliott Bay Action Program work assignment of U.S. EPA Contract No. 68-02-
4341. The primary objective of the Elliott Bay Action Program is to
identify toxic contamination and appropriate corrective actions in Elliott
Bay and the lower Duwamish River. Corrective actions include source
controls and sediment remedial actions. An Interagency Work Group (IAWG),
comprising representatives from the U.S. EPA, Washington Department of
Ecology (Ecology), and other resource management agencies, provides
technical oversight for all work conducted under this work assignment.
In this report, the relationship between source control and mitigation
of contaminated sediments is evaluated in two problem areas in Elliott Bay.
In a subsequent report, preferred alternatives for remediation of con-
taminated sediments in two Elliott Bay problem areas will be identified.
The following reports are in or have been drafted under the Elliott Bay
Action Program:
¦ Analysis of toxic problem areas (PTI and Tetra Tech 1988)
¦ Evaluation of potential contaminant sources (Tetra Tech
1988a)
¦ Development of a revised action plan (PTI and Tetra Tech in
preparation)
¦ Evaluation of the relationship between source control and
recovery of contaminated sediments (this report)
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Development of a storm drain monitoring approach (Tetra Tech
1988d)
Evaluation of sediment remedial alternatives (Tetra Tech
1988b)
Development of a monitoring approach (EVS and Tetra Tech in
preparation).
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CONTENTS
Paoe
LIST OF FIGURES v1
LIST OF TABLES viii
EXECUTIVE SUMMARY xi
1.0 INTRODUCTION 1
1.1 OBJECTIVES 1
1.2 OVERVIEW OF STUDY 1
1.3 STUDY AREA 2
1.3.1 Denny Way CSO Site 4
1.3.2 Duwamish River Slip 4 4
2.0 TECHNICAL APPROACH 7
2.1 IDENTIFICATION OF CLEANUP GOALS 7
2.2 IDENTIFICATION OF PROBLEM CHEMICALS 9
2.3 IDENTIFICATION OF SOURCES 14
2.4 FORMULATION OF THE SEDIMENT RECOVERY MODEL 16
2.5 PARAMETER IDENTIFICATION 20
2.5.1 Sediment Accumulation 21
2.5.2 Surface Mixed Layer 22
2.5.3 Chemical Persistence 23
2.5.4 Incoming Contaminant Concentration 25
3.0 APPLICATION 28
3.1 MODEL APPLICATION ASSUMPTIONS 30
3.2 DENNY WAY CSO 31
3.2.1 Source Summary 31
3.2.2 Identification of Indicator Chemicals 34
3.2.3 Identification of a Sediment Accumulation Rate 37
3.2.4 Sediment Recovery Scenarios 46
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3.3 DUWAMISH RIVER SLIP 4 50
3.3.1 Source Summary 50
3.3.2 Identification of Indicator Chemicals 54
3.3.3 Sediment Accumulation Rate 54
3.3.4 Sediment Recovery Results 61
4.0 MODEL LIMITATIONS AND RECOMMENDATIONS 66
REFERENCES 70
APPENDICES
A. Sediment Contaminant Data, Denny Way CSO Problem Area A-l
B. Sediment Contaminant Data, Duwamish River Slip 4 Problem
Area B-l
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FIGURES
Number Page
1 Project Location: Elliott Bay and the lower Duwamish River 3
2 Problem area locations: Denny Way CSO and Slip 4 5
3 Flow chart for the development of sediment recovery scenarios 8
4 Flow chart for the identification of indicator chemicals 15
5 Schematic of processes controlling chemical concentrations
in surface sediments 19
6 Schematic of hypothetical sediment recovery modeling results 29
7 Sampling station locations in Metro's Denny Way CSO source
toxicant investigation 33
8 Sampling station locations in the Denny Way CSO problem area 38
9 Areal distribution of mercury concentrations in Denny Way
surficial sediments, corrected for background concentration
and normalized to the target cleanup goal 39
10 Areal distribution of zinc concentrations in Denny Way
surficial sediments, corrected for background concentration
and normalized to the target cleanup goal. 40
11 Areal distribution of fluoranthene concentrations in Denny Way
surficial sediments, normalized to the target cleanup goal 41
12 Areal distribution of chrysene concentrations in Denny Way
surficial sediments, normalized to the target cleanup goal 42
13 Areal distribution of butyl benzyl phthalate concentrations
in Denny Way surficial sediments, normalized to the target
cleanup goal 43
14 Areal distribution of bis(2-ethylhexyl)phthalate concen-
trations in Denny Way surficial sediments, normalized to the
target cleanup goal 44
15 Areal distribution of total PCB concentrations in Denny Way
surficial sediments, normalized to the target cleanup goal 45
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16 Sediment recovery model results for the Denny Way problem
area: enrichment ratios based on maximum concentrations vs.
sediment recovery time given 100 percent source control for
sedimentation rates of 0.2 cm/yr (a) and 0.7 cm/yr (b)
17 Sediment recovery model results using five concentrations of
butyl benzyl phthalate found in the Denny Way problem area:
enrichment ratio vs. sediment recovery time given 100 percent
source control for sedimentation rates of 0.2 cm/yr (a) and
0.7 cm/yr (b).
18 Summary of PCB data for Slip 4 drains
19 Location of sampling stations in Slip 4
20 Areal distribution of total PCB concentrations in Slip 4
sediments, normalized to the target cleanup goal
21 Areal distribution of chromium concentrations in Slip 4
sediments, normalized to the target cleanup goal
22 Areal distribution of fluoranthene concentrations Slip 4
sediments, normalized to the target cleanup goal
23 Areal distribution of 4,4'-DDD concentrations in Slip 4
sediments, normalized to the target cleanup goal
24 Sediment recovery model results for Slip 4: enrichment
ratios based on maximum concentration vs. sediment recovery
time given 100 percent source control for sedimentation
rates of 0.8 cm/yr (a) and 2.0 cm/yr (b).
25 Sediment recovery model results for Slip 4: enrichment ratio
vs. sediment recovery time for all concentrations of PCBs
observed given 100 percent source control for sedimentation
rates of 0.8 cm/yr (a) and 2.0 cm/yr (b).
48
49
51
56
57
58
59
60
63
65
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TABLES
Number Paoe
1 Puget Sound AET values 10
2 Identification of indicator chemicals in Denny Way CSO
offshore sediments 35
3 Description of drains discharging into Slip 4 52
4 Identification of indicator chemicals in Duwamish River
Slip 4 sediments 55
viii
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ACKNOWLEDGMENTS
This document was prepared by Tetra Tech, Inc., under the direction of
Dr. Jean M. Jacoby, for the U.S. Environmental Protection Agency in partial
fulfillment of Contract No. 68-02-4341.
This project was funded through the National Estuary Program under the
authorities of the Clean Water Act as amended. Funding was approved by the
U.S. EPA Office of Marine and Estuarine Protection. Dr. Jack Gakstatter and
Ms. Clare Ryan served as U.S. EPA Project Officers, and Dr. Don Wilson
served as the Tetra Tech Program Manager.
The primary authors of this report are Ms. Lynne Kilpatrick-Howard, Dr.
Jean Jacoby, and Dr. William Brownlie of Tetra Tech. Dr. Don Wilson assisted
in modification of the model formulation and provided critical technical
review of this document. Ms. Marcy Brooks-McAuliffe of Tetra Tech performed
technical editing and supervised report production. The approach presented
in this document is based on work conducted for the Commencement Bay
Nearshore/Tideflats Feasibility Study by Tetra Tech for Ecology and U.S.
EPA. Mr. G. Patrick Romberg of Municipality of Metropolitan Seattle (Metro)
and Dr. Lucinda Jacobs of PTI Environmental Services provided technical
guidance on various aspects of this report. Evaluation of sources of
contaminants in the study areas was performed by Ms. Beth Schmoyer of Tetra
Tech. Ms. Stacey Vineberg of Tetra Tech provided data management support
and assisted in the model execution.
The Elliott Bay Toxics Action Program has benefited from the participa-
tion of IAWG and a Citizen's Advisory Committee (CAC). Duties of the IAWG
and CAC members included 1) reviewing program documents, agency policies,
and proposed actions; 2) providing data reports and other technical
information to U.S. EPA; and 3) disseminating action program information to
respective interest groups or constituencies. We thank the IAWG and CAC
members for their past and continuing efforts. We are especially grateful
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to Ms. Joan Thomas, Mr. Gary Brugger, and Mr. Dan Cargill for chairing the
IAWG, and to Mr. David Schneidler and Ms. Janet Anderson for co-chairing the
CAC.
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EXECUTIVE SUMMARY
The goal of the Elliott Bay Action Program is to identify toxic
contamination and appropriate corrective actions to mitigate contamination
in Elliott Bay and the lower Duwamish River. Under this program, federal,
state, and local agencies cooperate to respond to toxic contamination
problems. One component of this program involves predicting the natural
recovery of contaminated sediments in areas undergoing source control
actions.
This study was undertaken to evaluate the relationship between source
control and mitigation of sediment contamination in two high-priority
problem areas in Elliott Bay, Seattle, Washington. An Interagency Work
Group, comprising representatives from the U.S. EPA, Ecology, and other
resource management agencies, selected the Denny Way and Slip 4 problem
areas based on chemical contamination in offshore sediments. The time
necessary for sediment concentrations to be reduced to the target cleanup
goal after complete source elimination is estimated for each problem area
through the application of the Sediment Contamination Assessment Model
(SEDCAM), which was developed during the Commencement Bay Nearshore/Tideflats
Feasibility Study (Tetra Tech 1987a). In addition, the fraction of source
control required to maintain sediment concentrations at the level of the
target cleanup goal is predicted for each problem area. The target cleanup
goals are based on the "apparent effects threshold" (AET) approach (Tetra
Tech 1986). The focus of the AET approach is to identify concentrations of
contaminants in sediments that are associated with statistically significant
biological effects (relative to reference conditions). The results of this
study are intended to provide guidance for Ecology and U.S. EPA in the use
of sediment contamination data and sediment criteria in toxic source control
activities.
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The formulation of the relationship between source loading and sediment
accumulation of problem chemicals is essential to the development of
sediment recovery scenarios. Variables that are important in understanding
the sediment accumulation process include:
¦ The concentration of problem chemicals in recently deposited
material and surface sediments
¦ Sedimentation rate
¦ Mixed layer depth
¦ The rate at which problem chemicals are lost due to biodegra-
dation and diffusion across the sediment water interface.
SEDCAM is a mass balance equation that utilizes these variables to predict
contaminant concentrations in surficial sediments as a function of time.
The mass balance allows the change in concentration of a contaminant to be
expressed as a function of contaminant input by accumulation and contaminant
losses by burial and decay.
The rate at which sediments accumulate and the extent of their mixing
in surficial layers are processes that influence the ability of the
environment to dilute and attenuate contaminant input. Therefore, informa-
tion on sediment accumulation and mixing processes in a given problem area
is essential to adequately predict how concentrations of chemicals found in
the surface mixed layer vary over time.
Very few core samples have been collected in either the Denny Way or
Slip 4 problem areas that allow accurate characterization of the sedimenta-
tion rate and mixed layer depth over the spatial area of contamination. The
depositional parameters in the Denny Way problem area were estimated based
on studies performed by Romberg et al. (1987) in the vicinity of the outfall
and by Carpenter et al. (1985) in shallow central Puget Sound bays. Two
sedimentation rates (0.7 and 0.2 cm/yr) were selected for the model based on
xii
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the above studies to provide a range in sediment recovery scenarios in this
area.
Depositional patterns in riverine systems are not well characterized
and sedimentation rates in these systems are expected to be highly variable.
Therefore, sedimentation rates of 0.8 cm/yr and 2.0 cm/yr were estimated for
the Duwamish River Slip 4 problem area. The rate, 0.8 cm/yr, is expected
to be a minimum rate resulting in longer sediment recovery times than those
estimated using a sedimentation rate of 2.0 cm/yr. In addition to sedimen-
tation rates, mixing depth, chemical persistence (i.e., decay rate),
concentration of contaminants in the surface mixed layer, and the concen-
tration of the incoming contaminants are important processes controlling the
concentration of contaminants in surface sediments.
A mixed layer depth of 10 cm was estimated for both problem areas and
is based on work by Carpenter et al. (1985) as well as the Commencement Bay
Feasibility Study (Tetra Tech 1987b). Decay rates for problem chemicals
were estimated during the Commencement Bay Feasibility Study (Tetra Tech
1987b) and were negligible for most chemicals. The concentration of a
contaminant in the surface mixed layer was estimated to be the maximum
concentration of the chemical observed in the problem area. This estimation
is expected to be the most environmentally protective and thus the predicted
recovery times are a maximum. The concentration of an incoming contaminant
was estimated as a function of the concentration in the mixed layer and the
degree of source control applied.
The sediment recovery results predicted by SEDCAM are based on four
assumptions. First, the relationship between source loading and sediment
accumulation prior to source control is assumed to be constant over time.
This is the steady-state assumption. If source loading has increased or
decreased recently the steady-state assumption will either over estimate or
under estimate the recovery time of sediments. Second, the recommended
sediment cleanup goals, which are based on Apparent Effects Threshold (AET)
values, are assumed to be appropriate. Third, the implementation of source
xiii
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control measures is assumed to be feasible. And fourth, the model assumes
that mixing in the surface mixed layer occurs instantaneously.
Mercury, fluoranthene, chrysene, butyl benzyl phthalate, bis(2-ethyl-
hexyl)phthalate, 4,4'-DDT, and total PCBs were selected as indicator
chemicals for the development of sediment recovery scenarios in the Denny
Way CSO problem area. In addition, for the purpose of evaluating the
sediment recovery time for a metal other than mercury, sediment recovery
scenarios were also developed for zinc. The predicted effect of complete
source elimination on the recovery time of the indicator chemicals is based
on the maximum concentration observed in the surface sediments for each
indicator chemical. At a sedimentation rate of 0.2 cm/yr, it was estimated
that acceptable surface sediment concentrations (i.e., less than the
sediment cleanup goals) of mercury will not be achieved in the problem area
before 90 yr after loading has been eliminated. Zinc concentrations, on the
other hand, could reach the cleanup goal in approximately 40 yr. Acceptable
surface sediment concentrations of fluoranthene, chrysene, butyl benzyl
phthalate, bis(2-ethylhexyl)phthalate, and 4,4'-DDT will be achieved between
135 and 180 yr. In contrast, at a sedimentation rate of 0.7 cm/yr, sediment
concentrations of mercury are expected to be reduced to an acceptable level
in approximately 27 yr. At this sedimentation rate, zinc is predicted to
recover in 12 yr, while acceptable concentrations of the additional indicator
chemicals are expected to be achieved between 37 and 52 yr.
The predicted effect of completely eliminating source input to Slip 4
on the recovery time of sediments contaminated with chromium, fluoranthene,
PCBs, and 4,4'-DDD is based on the maximum concentration observed for these
chemicals in the problem area. At a sedimentation rate of 0.8 cm/yr, the
model predicts that concentrations of chromium and fluoranthene will reach
acceptable levels between 11 and 15 yr. Acceptable concentrations of
4,4'-DDD are expected to be achieved in approximately 37 yr, while PCB
concentrations are not predicted to recover for 48 yr. In contrast, at a
sedimentation rate of 2.0 cm/yr, it is estimated that acceptable levels of
PCBs in Slip 4 could be achieved 19 yr after loading has been eliminated.
At this sedimentation rate, acceptable surface sediment concentrations of
xiv
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chromium, fluoranthene, and 4,4'-DDD are predicted to be achieved between 5
and 15 yr after 100 percent source control has been implemented.
There are several factors that limit the ability of the model to
precisely reproduce real-world conditions. Some of the limitations are
inherent in the formulation of the model while others are based on the lack
of available data. The most significant limitations of the model include
the following:
¦ The availability of accurate sediment accumulation rates
¦ The accurate quantification of chemical-specific decay rates
¦ The assumption that mixing in the surface mixed layer occurs
instantaneously
¦ The availability of source loading and ancillary data
¦ The appropriateness of the steady-state assumption.
However, SEDCAM can be a useful tool to assess the relationship between
source control and the recovery of contaminated sediments despite its
limitations. Several factors have been identified that would facilitate the
refinement of the model:
¦ Improved contaminant loading data
¦ Well-characterized sediment accumulation rates and sediment
depositional patterns
¦ Applicable chemical-specific decay rates due to biodegradation
and diffusion
¦ Validation of sediment recovery predictions through monitor-
ing.
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Based on the application of SEDCAM to the two high-priority probl
in Elliott Bay the following conclusions can be drawn:
¦ Source elimination alone is not expected to result in
sediment recovery in either the Denny Way CSO problem area or
Slip 4 within a reasonable timeframe because of the current
level of contamination
¦ Following sediment remediation, source control levels of
94 percent or greater in the Denny Way CSO and 98 percent or
greater in Slip 4 will be required to maintain acceptable
sediment quality in each problem area.
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1.0 INTRODUCTION
1.1 OBJECTIVES
This study was undertaken to evaluate the relationship between source
control and mitigation of sediment contamination in two high-priority
problem areas in Elliott Bay, Seattle, Washington. The degree of source
control required to attain acceptable sediment concentrations in a reasonable
timeframe and in the long term is estimated. The feasibility of attaining
acceptable levels in a reasonable timeframe will help determine appropriate
corrective actions, including sediment remedial measures.
This document provides guidance for Ecology and U.S. EPA in the use of
sediment contamination data and sediment criteria in toxic source control
activities. The approach presented in this document is based on work
conducted for the Commencement Bay Nearshore/Tideflats Feasibility Study
(Tetra Tech 1987a). In that study, sediment recovery was predicted through
application of the SEDCAM. The appropriateness of SEDCAM for use in Elliott
Bay and Duwamish River habitats is evaluated in this document. The model is
then applied to estimate natural sediment recovery in two problem areas
within Elliott Bay.
1.2 OVERVIEW OF STUDY
Evaluation of the relationship between source control and sediment
recovery is based on data collected and compiled In support of the Elliott
Bay Action Program to identify and rank problem areas, chemicals, and
contaminant sources (PTI and Tetra Tech 1988; Tetra Tech 1988a). This
evaluation consists of three major components: 1) technical approach,
2) model application, and 3) limitations and recommendations.
Section 2.0 provides a description of the technical approach. In this
section, sources of contaminants, cleanup goals, and problem chemicals are
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identified. In addition, the relationship between contaminant sources and
sediment accumulation is formulated and model parameters are identified.
In Section 3.0, results of the model as applied to the two selected problem
areas are presented. Potential limitations and recommended modifications of
the model are discussed in Section 4.0.
1.3 STUDY AREA
Elliott Bay is a small embayment (21 km^) located on the eastern shore
of Puget Sound approximately midway between Admiralty Inlet and the Tacoma
Narrows (Figure 1). The bay lies adjacent to the City of Seattle (estimated
population of 488,200). The inner bay receives fresh water from the Duwamish
River, a salt-wedge estuary whose mean runoff varies from approximately
12 m^/sec in August to approximately 82 m^/sec in January (Baker et al.
1983). The nearshore areas of Elliott Bay, as well as the lower reaches of
the Duwamish River, have been significantly altered from their natural
states. The lower 6 mi of the once-meandering river is now a straightened
navigational channel, and the formerly expansive Seattle mudflats are now the
equally vast industrial areas of the city.
Two problem areas were selected by the IAWG to evaluate the relationship
between source control and recovery of contaminated sediments. One of the
two problem areas selected by the work group was the Denny Way combined
sewer overflow (CSO) and its associated receiving environment. This site
was selected because sediments are highly contaminated and because ancillary
source and offshore data from previous studies are available (PTI and Tetra
Tech 1988). The work group recommended that the Denny Way CSO site also be
used to evaluate sediment remedial alternatives under a separate task of the
Elliott Bay Action Program (Tetra Tech 1988b). The second site selected by
the work group was Slip 4 in the Duwamish River. Polychlorinated biphenyl
(PCB) contamination in storm drain and offshore sediments prompted selection
of this site. It was also selected to allow evaluation of the SEDCAM
approach in a riverine environment. The selected sites are described below.
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PORT ANGELES
. Port
Gardner
EVERETT
BREMERTON
Commtnc*m»nl
Bay
v ---^TACOMA
SHELTON
10
wmmd mile»
kilometers
Figure 1. Project location: Elliott Bay and the lower Duwamish River.
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1.3.1 Penny Wav CSQ Site
The Denny Way CSO, located along the northern shore of Elliott Bay
(Figure 2), is the largest CSO discharging untreated wastewater into
Elliott Bay. It discharged a total average volume of 500 Mgal/yr from
approximately 30 to 60 events during wet years 1981-1983 when trunk lines
leading to the municipal wastewater treatment plant overflowed (Romberg
et al. 1987). These are referred to as overflow events. The service area
consists of approximately 1,900 ac of mixed residential and commercial land.
Although toxicant loading from this CSO has been decreasing in recent years,
the Denny Way CSO has been identified as a major contributor of toxicants to
bottom sediments near the site (Romberg et al. 1987; PTI and Tetra Tech
1988). Elevated concentrations of organic toxicants and heavy metals are
present in bottom sediments near the outfall (Tomlinson et al. 1980; Malins
et al. 1980; Romberg et al. 1984; Romberg et al. 1987; PTI and Tetra Tech
1988). In addition, altered benthic communities have been observed
concomitant with elevated chemical concentrations in the vicinity of the
outfall (Armstrong et al. 1978; Cominskey et al. 1984; Chapman et al. 1982).
Recent source control efforts by Metro have reduced toxicant loading to the
CSO (Romberg et al. 1987). However, sediment remedial actions may be
required to improve environmental conditions in offshore sediments (Romberg
and Sumeri 1988). Extensive spatial coverage of contaminant concentrations
in the vicinity of the outfall facilitated identification of problem
chemicals at this site.
1.3.2 Duwamish River Slip 4
Slip 4 is a riverine slip in the Duwamish River (Figure 2). The slip is
an area of concern because highly elevated concentrations of PCBs have been
measured in surficial sediments (summarized in Appendix B of Tetra Tech
1988d). High levels of PCBs have also been measured in sediments from three
of the four storm drains that discharge to the slip. It is not known
whether there is an ongoing source of PCBs in this drainage basin. A more
detailed discussion of the source status of Slip 4 1s presented in Sec-
tion 3.3.
4
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WEST POINT
PIER9CV91
DENNY WAY CSO
FORMER PIER 71
MAGNOLIA
BLUFF
ELLIOTT
BAY
DUWAMISH
HEAD
HARBOR
&CJSLAND
ALKI
POINT
KQA.OQQ
ISLAND
SLIP 4
Figure 2. Problem area locations: Denny Way CSO and Slip 4.
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The SEDCAM approach was not developed for use in a riverine habitat,
and lack of available data on sedimentation rates and contaminant loading
estimates may limit its application in the Duwamish River. The compounding
effects of dredging, navigation, river currents and variable sedimentation
rates in the Duwamish River may also limit its application.
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2.0 TECHNICAL APPROACH
There are six components of the approach leading to the development of
sediment recovery scenarios (Figure 3):
¦ Identification of cleanup goals
¦ Identification of problem areas and problem chemicals
¦ Identification of sources
¦ Formulation of an analytical approach to examine the
relationship between source loading and sediment accumulation
of problem chemicals
¦ Identification of key parameters
¦ Evaluation of the predicted response of sediments to source
control.
Each component is detailed in the following sections.
2.1 IDENTIFICATION OF CLEANUP GOALS
A working definition of acceptable chemical concentration is required
prior to assessing whether sediments will recovery in a reasonable timeframe.
Because criteria for sediments are not yet available, target cleanup goals
are based on the AET approach (Tetra Tech 1986). The focus of the AET
approach is to identify concentrations of contaminants in sediments that are
associated with statistically significant biological effects (relative to
reference conditions). Biological indicators used to develop AET values
include benthic infauna abundance and toxicity bioassays (i.e., amphipod
mortality, oyster larvae abnormality, and Microtox bioluminescence). For a
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SOURCE(S)
ONGOING ?
NO
YES
SEDIMENT PROFILES
DEFINE RELATIONSHIP BETWEEN SOURCE
LOADING AND SEDIMENT ACCUMULATION
LOADING DATA
INPUT IS DECREASING
OVER TIME OR CICO
FORMULATE CI AS A FUNCTION OF CO
DETERMINE FUTURE STEADY-STATE
CONCENTRATION
DETERMINE RECOVERY TIME FOR CONDITIONS OF COMPLETE SOURCE ELIMINATION
DETERMINE WHAT REDUCTION WILL EFFECT RECOVERY IN A REASONABLE TIME
FRAME (RECOVERY MAY NOT BE POSSIBLE EVEN AT 100% REDUCTION)
STEADY-STATE
MODEL SEDIMENT RECOVERY
WITH NO ACTION
IDENTIFY TARGET
CLEANUP GOALS
IDENTIFY INDICATOR
CHEMICAL(S) IN EACH GROUP
DEFINE INPUT PATHWAY
- Pipe Discharge
- Groundwater Infiltration
- Runoff
- Other
DETERMINE REDUCTION REQUIRED TO EFFECT AN ACCEPTABLE FUTURE
STEADY-STATE CONCENTRATION
Figure 3. Flow chart for the development of sediment recovery
scenarios.
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given chemical and a specific biological indicator, the AET is the concen-
tration above which statistically significant biological effects occurred in
all samples of sediments analyzed. AET values have been proposed for
64 organic and inorganic toxic chemicals using synoptic chemical and
biological data from 200 stations in Puget Sound (Tetra Tech 1987b). For
each chemical, a separate AET was developed for each biological indicator,
resulting in four sets of AET values. A list of the highest and lowest AET
for each chemical is provided in Table 1. Target cleanup goals are based on
the lowest AET value for problem chemicals.
AET values for iron, manganese, nickel, antimony, and chromium were not
used as cleanup goals or to identify chemicals. Iron and manganese are not
normally considered toxic chemicals. The AET values for antimony and
chromium were not used because of the likelihood that analytical methods
used to generate the AET for these chemicals are not directly comparable to
the methods used in all historical studies. The AET value for nickel was
not used because the range of nickel concentrations in the database used to
generate Puget Sound AET values is relatively limited (PT1 and Tetra Tech
1988).
The use of the lowest AET as the target cleanup goal is considered to
yield criteria with a high degree of environmental protectiveness and thus
leads to the development of "worst-case" sediment recovery scenarios.
Because the model is sensitive to the value of the target cleanup goal,
confidence in the estimated recovery times depends in part on the uncertainty
inherent in the AET values. For some contaminants (e.g., total PCBs) the
most sensitive biological indicator results in a target cleanup goal that is
significantly lower than that produced by any of the other indicators.
2.2 IDENTIFICATION OF PROBLEM CHEMICALS
Problem chemicals were assigned priority based on the relative number of
stations in each study area where concentrations exceeded the target cleanup
goal. Chemistry data compiled from the following references were utilized
to identify the problem chemicals in each of the study areas:
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TABLE 1. PU6ET SOUND AET VALUES
(ug/kg dry weight = ppb for organic compounds;
mg/kg dry weight = ppm for metals)
Lowest AETa Highest AET
LPAHb
5,200
6,100
Naphthalene
2,100
2,400
Acenaphthylene
560
640
Acenaphthene
500
980
Fluorene
540
1,800
Phenanthrene
1,500
5,400
Anthracene
960
1,900
HPAHC
12,000
38,000
Fluoranthene
1,700
9,800
Pyrene
2,600
11,000
Benzo(a)anthracene
1,300
4,500
Chrysene
1,400
6,700
Benzof1uoranthenes
3,200
8,000
Benzo(a)pyrene
1,600
6,800
Indeno(1,2,3-c,d)pyrene
600
880
Dibenzo(a.h)anthracene
230
1,200
Benzo(g,h,i)perylene
670
5,400
Total PCBs
130
2,500
Total Chlorinated Benzenes
170
680
1,3-Dichlorobenzene
1,4-Dichlorobenzene
110
260
1,2-Dichlorobenzene
35
50
1,2,4-Tri chlorobenzene
31
64
Hexachlorobenzene
70
230
Total Phthalates
3,300
3,400
Dimethyl phthalate
71
160
Diethyl phthalate
200
200
Di-n-butyl phthalate
1,400
1,400
Butyl benzyl phthalate
63
470
Bis(2-ethylhexyl) phthalate
1,900
1,900
10
-------
TABLE 1. (Continued)
Lowest AETa Highest AET
Pesticides
4,4'-DDE
9
15
4,4'-DDD
2
43
4,4'-DDT
3.9
11
Phenols
Phenol
420
1,200
2-Methylphenol
63
63
4-Methylphenol
670
1,200
2,4-Dimethyl phenol
29
29
Pentachlorophenol
—
—
2-Methoxyphenol
930
930
Miscellaneous Extractables
Hexachlorobutadiene
120
290
1-Methylphenanthrene
310
370
2-Methylnaphthalene
670
670
Bi phenyl
260
270
Dibenzothiophene
240
250
Dibenzofuran
540
540
Benzyl alcohol
57
73
Benzoic acid
650
650
n-Ni trosodi phenyl ami ne
40
220
Volatile Oraanic Compounds
Tetrachloroethene
140
140
Ethyl benzene
33
37
Total xylenes
100
120
Metals
Antimony
3.2
26
Arsenic
85
700
Cadmium
5.8
9
Copper
310
800
Lead
300
700
Mercury
0.41
2
Nickel
28
49
Silver
5.2
5
Zinc
260
1,600
11
-------
TABLE 1. (Continued)
a By definition, the lowest AET is the sediment cleanup goal,
b LPAH = Low molecular weight polynuclear aromatic hydrocarbons.
c HPAH = High molecular weight polynuclear aromatic hydrocarbons.
Reference: Tetra Tech (1987b).
1Z
-------
¦ Denny Way CSO
Mai ins et al. (1980)
Romberg et al. (1984)
Romberg et al. (1987)
PTI and Tetra Tech (1988)
¦ Duwamish River Slip 4
U.S. EPA (1982-1983)
Schlender, M. (16 April 1985, personal communication)
Sample, T. (23 October 1987, personal communication)
PTI and Tetra Tech (1988).
These data are presented in Appendices A and B.
For chemicals that were measured at multiple stations within a problem
area, a high priority was assigned if the compound was detected at a
concentration greater than the target cleanup level in at least 40 percent
of the samples. A low priority was assigned to chemicals that were detected
at a frequency of 40 percent or less. In addition, a low priority was
assigned to contaminants which were analyzed for at only one station within
a problem area.
In each problem area, indicator chemicals were identified. Indicator
chemicals are those chemicals that are expected to drive sediment recovery
scenarios and dictate sediment remedial action. In general, these indicator
chemicals were selected from those classified as high priority. If no more
than two compounds within each chemical compound class (e.g., metals, LPAH,
HPAH) were assigned a high priority, each chemical was identified as an
13
-------
indicator chemical. If more than two compounds within a chemical class were
designated as high priority then the entire class of compounds was considered
a potential problem. Indicator chemicals within the problem class were
selected based on the following criteria:
¦ Frequency of target cleanup goal exceedances
¦ Spatial distribution of concentrations exceeding the cleanup
goals
¦ Magnitude of cleanup goal exceedance
¦ Resistance to degradation.
A schematic of the process used to identify high priority, low priority, and
indicator chemicals is presented in Figure 4. For each problem area, the
SEDCAM approach was used to estimate the changes in concentrations over time
of indicator chemicals in the surface sediments in each problem area.
2.3 IDENTIFICATION OF SOURCES
The status of contaminant sources is a critical element in the
development of sediment recovery scenarios. Sources can be classified
either as ongoing or historical. In addition to active industries, ongoing
sources include industries that have ceased activities but whose property
contains contaminants that can still be transported to the marine environ-
ment. Historical sources consist of industries that have ceased activities
and whose property no longer contains contaminants that can be transported
to the marine environment. Historical sources require no further charac-
terization. Thus, sediment recovery scenarios can be developed with the
assumption that input from historical sources is negligible.
Ongoing sources require further characterization before sediment
recovery scenarios can be developed. Characterization of ongoing sources
should include the following factors:
14
-------
NO
WAS THE CHEMICAL
ANALYZED MORE THAN ONCE?
YES
WAS THE CONCENTRATION
GREATER THAN THE TARGET
CLEANUP GOAL AT LEAST
40 PERCENT OF THE TIME?
NO
LOW PRIORITY
CHEMICAL
YES
IDENTIFY CHEMICAL
AS AN INDIVIDUAL
INDICATOR CHEMICAL
NO
YES
ENTIRE COMPOUND CLASS IS A POTENTIAL PROBLEM.
THEREFORE. SELECT INDICATOR CHEMICAL(S) BASED ON:
FREQUENCEY OF TARGET CLEANUP GOAL EXCEEDANCES
SPATIAL DISTRIBUTION OF CONCENTRATIONS EXCEEDING
TARGET CLEANUP GOAL
MAGNITUDE OF TARGET CLEANUP GOAL EXCEEDANCE
RESISTANCE TO DEGRADATION
LOW PRIORITY
CHEMICAL
HIGH PRIORITY
CHEMICAL
IDENTIFY THE CLASS OF
COMPOUNDS IN WHICH
THIS COMPOUND LIES
ARE THERE MORE THAN TWO CHEMICALS
WITHIN THIS COMPOUND CLASS WHICH
EXCEED THE TARGET CLEANUP GOAL
AT LEAST 40 PERCENT OF THE TIME?
Figure 4. Flow chart for the identification of indicator chemicals.
15
-------
¦ Transport pathway to the marine environment (e.g., groundwater
infiltration, storm drain, ditch, process effluent pipe)
¦ Temporal trends in source loading
¦ Short-term variability in source loading.
The transport pathway will determine the type of source control technologies
that can be applied, which in turn will determine the extent to which
sources can be controlled. These facets of source control are not discussed
in this document, but are relevant to the future assessment of remedial
alternatives. Loading rates may vary significantly with time, especially
in cases where loading is dependent on precipitation (e.g., storm drains) or
sporadic disposal events (e.g., spills).
Source identifications for problem chemicals in the study areas was
complicated by a lack of source loading data. Major sources of problem
chemicals in the two study areas were identified under the Elliott Bay
Action Program (Tetra Tech 1988a) on the basis of one or more of the
following factors: proximity to areas of sediment contamination, known use
or disposal of a characteristic problem chemical, and measured loading of
problem chemicals. Major sources of problem chemicals detected in the
surficial sediment offshore of the Denny Way CSO were identified by Romberg
et al. (1987) and are summarized in Section 3.2.1. Information on sources
of contaminants to Slip 4 was compiled from a variety of studies and is
presented in Section 3.3.1.
2.4 FORMULATION OF THE SEDIMENT RECOVERY MODEL
The formulation of the relationship between source loading and sediment
accumulation of problem chemicals is essential to the development of
sediment recovery scenarios. Processes that influence the sediment concen-
tration of contaminants include 1) temporal changes in source input, 2)
sediment accumulation and mixing, 3) biodegradation, and 4) diffusive losses
across the sediment-water interface. An exact mathematical representation of
these processes would be extremely complex and would require an extensive
16
-------
amount of data, much of which are unavailable. SEDCAM is a mass balance
equation that attempts to predict the sediment concentration of contaminants
in relation to source loading, sedimentation rates, mixing, biodegradation,
and loss across the sediment-water interface. The model was developed for
and applied to the waterways of Commencement Bay (Tetra Tech 1987a) and is
evaluated here for application to two problem areas in Elliott Bay. SEDCAM
estimates the time required for concentrations of contaminants in sediments
to decrease to levels that are considered acceptable and is used to assess
the potential success of source control.
The simplicity of the model limits its ability to precisely reproduce
real-world conditions, but in the absence of more detailed knowledge of
processes and parameters affecting sediment contamination and recovery, the
model allows some predictions to be made.
The rate at which sediments accumulate and the extent of their mixing in
surficial layers are processes that influence the ability of the environ-
ment to dilute and attenuate contaminant input. Therefore, information on
sediment accumulation and mixing processes in a given problem area is
essential to adequately predict how concentrations of chemicals found in the
surface mixed layer vary over time.
Total sediment accumulation comprises both natural "background"
particulates and particulates deriving from contaminated sources. In the
absence of contaminant input, the accumulation of natural sediments buries
contaminated surface sediments, effectively decreasing the toxicity of
surface sediments. However, sediment mixing attenuates this effect by
mixing the deeper contaminated sediments upward to the surface. The
following variables are important in understanding the sediment accumulation
process:
¦ Concentration of problem chemicals in recently deposited
materi al
m Concentration of problem chemicals in surface sediments
17
-------
¦ Sedimentation rate
¦ Depth of the surface mixed layer
¦ Rate at which problem chemicals are lost because of biodegra-
dation and diffusion.
The sediment recovery model utilizes the above variables to predict
contaminant concentrations in surficial sediments as a function of time.
The link between contaminant source and sink is illustrated schem-
atically in Figure 5. The variation in chemical concentration (C) in the
surface mixed layer with time (t) is derived from a mass balance and is
described by the differential equation:
& ¦ C' * S . £-i-S . k * c (l)
dt D D Kc L I1'
change in concentration = accumulation - burial - decay over time
where:
C = Chemical concentration in the surface mixed layer (mg/g)
Cj = Concentration of contaminant in recently deposited material
after source control (mg/g)
S 3 Rate of accumulation of solid material in the sediments (cm/yr)
D = Depth of sediments in the surface mixed layer (cm)
kc » Combined first-order rate constant for contaminant loss by in situ
degradation and diffusive loss (1/yr).
The solution to this equation is:
-(kcD+S)t -(kcD+S)t
C • TS^MT * Ci * 1 - • D ~ Co * e D (2)
where:
18
-------
ACCUMULATION
SEAWATER
O
MIXED
LAYER
DECAY
SEDIMENTS
BURIAL
C| - CHEMICAL CONCENTRATION IN RECENTLY DEPOSITED SEDIMENT (mg/g)
C - CHEMICAL CONCENTRATION IN SURFACE MIXED LAYER (mg/g)
S - SEDIMENT ACCUMULATION RATE (cm/yr)
D - DEPTH OF THE MIXED LAYER (cm)
k<. - FIRST ORDER DECAY CONSTANT (1/yr)
Figure 5. Schematic of processes controlling chemical concentra-
tions in surface sediments.
19
-------
t = time (yr)
C0 = Concentration of contaminant in the surface mixed layer at t = 0
(mg/g).
The analytical solution assumes the following conditions:
¦ CJ, S, D, and kc are constant after source control implemen-
tation
¦ The sediment that constitutes the mixed layer is well mixed
¦ Cj represents the concentration of contaminant in recently
deposited material that settles (or is deposited) beyond the
sediment-water interface.
The parameter C0 is the initial concentration of a chemical contaminant
in surface sediments. The distribution of problem chemical concentrations
in Elliott Bay sediments were determined as part of the Elliott Bay Action
Program (PTI and Tetra Tech 1988) and related studies. The maximum
concentration of a problem chemical in surface sediments of a problem area
was used in this report to calculate sediment recovery time. The maximum
concentration of nearly all metals and organic compounds was observed at the
stations located closest to the outfalls. If dredging is conducted, C0 must
be represented by the contaminant concentration in the sediment horizon
exposed by dredging activity. The determination of other parameters (i.e.,
sedimentation rate, mixing depth, and decay constant) is more complex, and
is described 1n the following section.
2.5 PARAMETER IDENTIFICATION
Sedimentation rate, mixing depth, chemical persistence (I.e., decay
constant), and chemical loading are important processes controlling the
concentration of contaminants 1n surface sediments. Sedimentation rate and
mixing depth were not determined as part of the Elliott Bay Action Plan, and
are estimated from other studies conducted in Puget Sound and in similar
20
-------
environments (Carpenter et al. 1985; Lavelle et al. 1986; Tetra Tech 1987a).
Chemical persistence was evaluated for selected chemicals during the
Commencement Bay Feasibility Study (Tetra Tech 1987a). The approach and
decay constants determined as part of that study are described here. In
addition, any simplifying assumptions that eliminate the need to specify all
parameters which compose Ci will be presented.
2.5.1 Sediment Accumulation
Sediment accumulation rates are necessary to determine the time that
will elapse between controlling sources of contamination and reducing
surficial sediment concentrations (i.e., the response time). The sedimen-
tation rate (S) (cm/yr) is related to the mass accumulation rate (R)
(mg/cm^ yr) by the following expression:
R = S (1 - p)d (3)
where:
p ¦ porosity of sediments (unitless)
d = dry density of sediment (mg/cm^).
Sediment rates determined for the waterways within Commencement Bay were
derived from the analysis of excess Pb-210 and ranged from 0.14 cm/yr to
1.77 cm/yr (Tetra Tech 1987a). Recent Pb-210-derived mass accumulation
rates estimated by Carpenter et al. (1985) for shallow bays in the central
Puget Sound region range from 110 to 260 mg/cm2 yr and result in sedimenta-
tion rates of 0.22-0.66 cm/yr for sediment porosity equal to zero.
The technique of measuring changes in excess Pb-210 activity with depth
is often used in nearshore sediments because lead has a strong affinity for
particles. In addition, the half-life of the Isotope (22 yr) is appropriate
to the time scale of sediment accumulation. However, the accuracy of the
technique depends in part on constant sedimentation and Pb-210 accumulation
rates. Factors unique to the environmental setting of the two selected
problem areas complicate the application of this technique. These factors
include dredging activities, shipping traffic, bluff erosion, and temporal
21
-------
changes in deposition rates influenced by anthropogenic activities.
Because of these complications, a successful application of the excess
Pb-210 technique to the sediments offshore from the Denny Way CSO and in the
Duwamish riverine slip would not be anticipated. Alternative methods that
may be used to estimate the rate of sediment accumulation are described in
Tetra Tech (1987a) and include the following:
¦ Evaluation of sediment core discontinuities
¦ Evaluation of dredging records
¦ Review of bathymetric records
¦ Assessment of particulate loading from point sources.
The method used to estimate the sediment accumulation rate in the absence of
Pb-210 data in each problem area is described in more detail in Sec-
tions 3.2.2 and 3.3.2.
2.5.2 Surface Mixed Laver
Mixing of near-surface deposits occurs as a result of several factors
including the activity of benthic organisms. The mixing layer depth can
have a major influence on the response time of contaminant concentrations in
sediments after sources have been controlled. The value of the depth of the
surface mixed layer is important to the application of SEDCAM because it
effectively defines the size of the reservoir that will attenuate concentra-
tion changes brought on by source control. This is illustrated by consider-
ing the hypothetical case where the mixed layer depth is measured to be
zero. In terms of the model, this means that any change in the concentration
of a contaminant in incoming sediments 1s instantly registered in the
concentration of the surface sediments. Carpenter et al. (1985) observed
surface mixed layer depths ranging from 7.3 to 11 cm in central Puget Sound
shallow bays. The depths of the mixed layer determined for the Commencement
Bay waterways during the Commencement Bay Nearshore/Tideflats Feasibility
Study were derived from the analysis of excess Pb-210 and ranged from 0 to
22
-------
20 cm (Tetra Tech 1987a). A mixed layer depth of 10 cm was assumed to best
represent the average mixed layer depth in the Elliott Bay problem areas.
2.5.3 Chemical Persistence
SEDCAM incorporates a chemical-specific first-order rate constant, kc,
to represent the rate of total loss of contaminants from sediments that is
not accounted for by burial. The formulation of loss as first-order decay
assumes that loss is only a function of chemical concentration. The
processes considered most likely to cause contaminant losses from sediments
are microbial degradation and diffusion into the overlying water column. In
situ degradation and diffusion can effectively reduce sediment contaminant
concentrations over time, and thus are important considerations when
estimating recovery times. Microbially mediated degradation may also be
formulated as a zero- or second-order equation. The assumption of first-
order decay represents a generalized simplification of the degradation
process. Losses due to diffusion and biodegradation can be represented by
the following differential equation:
d£ = kc * C = kbi0 * C + kdif * C (4)
dt
where:
C ¦ Contaminant concentration in sediment at time t (mg/g)
kc = Combined first-order decay constant (1/yr)
kbio ~ Biodegradation component of decay constant (1/yr)
kdif = Diffusive component of decay constant (1/yr).
The approach used in the Commencement Bay Nearshore/Tideflats Feasi-
bility Study (Tetra Tech 1987a) and applied to the Elliott Bay problem areas
was to select the lowest, most environmentally protective decay rate values.
Such k values will result in upper estimates of recovery times for problem
areas. Even relatively small decay rate constants have a marked effect on
estimates of C (final sediment concentration at a given time). For example,
if sedimentation rate and total sediment depth in the mixed layer are
typically 1 cm/yr and 14 cm, respectively, and a value of kc » 0.07/yr
23
-------
(equivalent to a half-life of 9.9 yr, if half life = 0.693/kc) is assumed,
the expression in the exponential term of the solution to the model
(Equation 2) is as follows:
kcD + S = (0.07*14) + 1 B 0.98 + 1
D 14 14 (5)
Under the environmental conditions described above, a first-order decay
constant of 0.07/yr has an effect on recovery times similar to doubling the
sedimentation rate. As the decay rate constant decreases, its effect on the
recovery time of sediments diminishes. At a very small k, the recovery
time is dependent primarily on the sedimentation rate and the mixed layer
depth.
Microbial degradation incorporates most chemical processes that could
be expected to degrade compounds (e.g., oxidation, reduction, hydrolysis)
and is typically more efficient than abiotic chemical degradation processes
because of enzymatic catalysis (see Vogel et al. 1985). Also, the eventual
mineralization of organic compounds (i.e., degradation to inorganic constitu-
ents, such as CO2 and H2O) has been attributed almost entirely to biodegra-
dation (Lyman et al. 1982).
Losses associated with diffusion across the sediment-water interface
were incorporated into k values only for compounds for which mobility was
expected to be significant (based on octanol-water partition coefficients,
or k0W( which are indices of mobility of nonpolar organic compounds in
sediment/water systems). Diffusion was considered negligible for organic
compounds with log kow values >4 for reasons described in Commencement Bay
Nearshore/Tideflats Feasibility Study (Tetra Tech 1987a). Diffusive losses
would be expected to be minor for the nonpolar organic contaminants (e.g.,
PCBs) with high kQW values and correspondingly low aqueous solubilities.
The relative contributions of blodegradatlon and diffusion to the
combined first-order decay constant determined 1n the Commencement Bay
Nearshore/Tideflats Feasibility Study (Tetra Tech 1987a) for metals, PCBs,
polyaromatic hydrocarbons, chlorinated benzenes, trichloroethene (TCE),
24
-------
tetrachloroethene (TECE), and 4-methylphenol were applied to the model for
both Elliott Bay problem areas. The lowest values were chosen to estimate
first-order decay constants when possible. For all chemicals except TCE,
TECE, and 4-methylphenol, a value of 0/yr was assigned. A value of 0.69/yr
(i.e., half-life of 1 yr) was selected to represent potential diffusive loss
for TCE, TECE, and 4-methylphenol. These values should be refined if and
when empirical data become available.
2.5.4 Incoming Contaminant Concentration
The parameter Cj is the concentration of a problem chemical in recently
deposited sediments after source control. SEDCAM is used to evaluate
sediment recovery through the reduction of Cj. Because the value of Cj is
difficult to determine, the formulation of the parameter depends on the
amount of information available and the applicability of the simplifying
assumptions. Ci can be formulated as a function of the following variables:
¦ Source loading prior to source control
¦ Fraction reduction in loading due to source control measures
¦ Fraction of contaminant lost in transit between the point of
discharge and the point of deposition
¦ Depositional area
¦ Sedimentation rate.
However, simplifying assumptions that eliminate the need to specify all of
the parameters noted are desirable.
In many cases, a steady-state assumption can be applied (I.e., that
the system was in steady-state prior to implementation of source control
measures). This simply means that the input rate equals the removal rate,
so that the concentration of the contaminant 1n the well-mixed box (see
Figure 5) does not vary over time. The steady-state assumption is a useful
25
-------
simplification because the incoming contaminant concentration (Cj) does not
have to be quantified and can be represented by the equation:
Ci = C0 * fL * S * kcD
S
(6)
For the cases where kc - 0, Cj can be directly determined from C0 and the
degree of source control, f^ Thus, Equation 6 becomes:
Estimating Cj from source loading data was not practical in the
application of SEDCAM to either the area offshore from the Denny Way CSO or
the Duwamish River Slip 4. Source loading data are only available for
selected chemicals in the Denny Way CSO. Source loading of contaminants to
Slip 4 has not been determined to date. Therefore, the steady-state
assumptions were applied and Cj was formulated as a function of C0, as in
Equation 6.
In general, there are three cases that represent the relationship
between source loading and sediment accumulation prior to source control:
¦ Source loading is increasing over time, or surficial sediment
concentrations have not yet increased to levels supported by
accumulating contaminated particles
¦ Source loading is decreasing over time, or surficial sediment
concentrations have not yet adjusted to recent decreases in
contaminant loading
¦ Source loading is in steady-state with sediment accumulation.
Temporal trends in loading may be derived from source loading data, disposal
chronologies, and sediment profiles of problem chemicals. If source loading
has either increased or decreased recently, the steady-state approximation
ci = c0 * fL
(7)
26
-------
(i.e., Cj = C0) will underestimate or overestimate the concentration in
recently deposited sediments.
27
-------
3.0 APPLICATION
In this section, sediment recovery scenarios are developed using SEDCAM
for two selected problem areas in Elliott Bay. Several important pieces of
information are derived from the sediment recovery scenarios:
¦ Recovery times if sources of contamination are completely
eliminated
¦ Degree of source control required to effect sediment recovery
in the long term
¦ Long-term effect of not controlling sources.
Recovery times predicted for complete source elimination provide a
framework for evaluating the effectiveness of source control and the
relative severity of contamination by different problem chemicals. The
degree of source control required to effect sediment recovery in a reasonable
timeframe will be greater than that required for long-term recovery; mixing
of the surface sediments delays recovery, and the added time constraint must
be compensated for by more extreme source control measures. In many cases,
recovery in a reasonable timeframe may not be possible even with complete
source elimination because chemical concentrations in sediments are too high
or the sediment accumulation rate of clean material is too low. The long-
term effects of not controlling sources is only of interest for chemicals
associated with sources that are not in steady-state with sediment accumu-
lation (i.e., sources that are relatively new, or have displayed pronounced
increases or decreases in loading rates).
Results from the application of SEDCAM are presented in the format
shown in Figure 6. For complete source elimination, estimated recovery time
varies logarithmically with the ratio of contaminant concentration in
surface sediments to its respective cleanup goal (C0/Cq) (the enrichment
28
-------
0
10
20
30
40
SEDIMENT RECOVERY TIME (yr)
LEGEND
SLOPE DETERMINED BY SEDIMENTATION RATE
AND MIXED LAYER DEPTH (ASSUMES FIRST
ORDER DECAY RATE CONSTANT EQUALS ZERO)
SLOPE DETERMINED BY SEDIENTATION RATE.
MIXED LAYER DEPTH, AND FIRST ORDER DECAY
6. Schematic of hypothetical sediment recovery modeling
results.
29
-------
ratio). The slope of the line is determined by the sedimentation rate and
mixing depth specific to each problem area. For chemicals that are
degradable, the first-order decay constant may significantly influence the
slope of the line. The influence some of hypothetical first-order decay on
the recovery time of chemical A is shown in Figure 6 (dotted line) as a
decrease in recovery time from 36 to 14 yr. Uncertainty in values assigned
to depth of the mixed layer, sedimentation rate, and decay constant
influences the uncertainty in the estimated recovery time. The hatched area
around the solid line in Figure 6 represents an estimated uncertainty of
20 percent.
For certain problem chemicals, the enrichment ratio on the y-axis is
corrected for background concentrations. For example, all metals have
naturally occurring sediment concentrations. These concentrations become
important if they approach the value designated as cleanup goal. In Puget
Sound, for enrichment ratios exceeding 1, corrections greater than 10 percent
are only required for the metals zinc, mercury, and copper. The corrected
enrichment ratio is defined by:
- c°- cb (8)
CS CG- CB
where Cg is the background concentration and Cq is the target cleanup goal.
3.1 MODEL APPLICATION ASSUMPTIONS
The results from the application of the SEDCAM model to the two problem
areas in Elliott Bay are based on the following assumptions:
¦ The relationship between source loading and sediment
accumulation is constant over time (steady-state assumption)
¦ The recommended target cleanup goals are appropriate
30
-------
¦ The implementation of source control measures is feasible
¦ Mixing in the surface mixed layer occurs instantaneously.
Given the dynamic nature of the environmental setting of both problem
areas, the steady-state assumption is not expected to represent the true
relationship between source loading and sediment accumulation. However, the
assumption simplifies the application of the model when little or no source
loading data are available.
The recommended cleanup goals are based on the most sensitive of a
range of biological indicators. However, alternative goals may be based on
a narrower range of biological indicators and less conservative sediment
recovery scenarios may result.
The feasibility of source control depends on the ability to positively
identify source inputs and pathways and therefore varies with each problem
area.
The assumption that mixing in the surface mixed layer occurs instan-
taneously simply allows an analytical solution to the differential equation
(Equation 1) that describes the variation in contaminant concentration in
the mixed layer with time.
3.2 DENNY WAY CSO
3.2.1 Source Summary
The Denny Way CSO is the largest discharger to Elliott Bay and most
frequent overflow point in Metro's combined sewer system. The Denny Way CSO
discharges into Elliott Bay north of the Seattle downtown area at Denny Way.
It produced a total average overflow volume of 500 Mgal/yr from approximately
30-60 overflow events during wet years 1981-1983 when trunk lines leading to
the municipal wastewater treatment plant overflowed (Romberg et al. 1987).
The service area consists of almost 1,900 ac of mixed residential and
31
-------
commercial land. In previous studies, contaminated sediments and altered
benthic communities have been found offshore from the Denny Way CSO.
In 1986, Metro conducted a trial study in the Denny Way CSO drainage
basin to determine if toxicant sources could be identified and reduced,
pending a structural solution to eliminate CSO discharges (Romberg et al.
1987). As part of the investigation, Metro developed an inventory of
530 potential sources in the drainage basin based on Standard Industrial
Codes (SIC) and addresses from tax records. A questionnaire on wastewater
discharges and chemical use was sent to each company identified as a
potential source. Fifty-four percent of the businesses contacted responded
to the questionnaire. Those businesses that failed to respond were visited
or contacted by phone. Ninety-six potential sources were visited by Metro
inspectors to confirm the questionnaire survey information and collect
information to help develop practical source control strategies. In
addition, sediment and wastewater samples were collected at key points within
the CSO system (Figure 7) and analyzed for metals and organic toxicants.
Wastewater samples were collected for two different events at most stations
and sediment samples were collected once at each station (Romberg et al.
1987).
The highest metals concentrations in both wastewater and sediment
samples were measured in stations downstream of two industrial laundries
that discharge wastewater to the Denny Way CSO. In addition, a large volume
of accumulated sediments in one part of the CSO system (Lake Union Tunnel),
located downstream of both laundries, was found to have high metals
concentrations. Both laundries installed new pretreatment equipment in 1986
to reduce the toxicant loadings in their discharges. Based on preliminary
data, metals loadings in sediments and wastewater were estimated to have
been reduced by 50 percent for copper, 77 percent for lead, and 24 percent
for zinc after the pretreatment systems were installed (Romberg et al.
1987).
High concentrations of chromium and mercury in in-line discharge
samples were traced to a movie film developing facility. The facility has
been directed to use proper disposal practices, and as a result, the
32
-------
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Denny Local
~rilnag*
Elliott and
Harrison
W
Minor and
John
'Melrose
and Olive
w
Westlake
and Denny
LAKE UNION
TUNNEL
DENNY WAY
REGULATOR STATION
ELLIOTT BAY r~
INTERCEPTOn1_
ELUOTT BAY
CSO
OUTFALL
R«f*renc«: 1967.
Figure 7. Sampling station locations in Metro's Denny Way
CSO source toxicant investigation.
33
-------
toxicant input from this source is expected to be eliminated or greatly
reduced (Romberg et al. 1987).
Analyses of organic compounds were generally not as effective in
tracing contaminant sources as analyses of metals because of large variations
in organic compound concentrations among different sampling events at one
station. However, concentrations of toluene, tetrachloroethane, and ethyl
benzene were typically highest (range of 50-200 ug/L) in the wastewater
samples collected downstream of the two industrial laundries (Romberg et al.
1987). These three volatile organic compounds were also present at
relatively high concentrations (300-800 ug/kg wet weight) in sediment
samples collected immediately downstream of the laundries. In addition,
naphthalene appeared to be associated with the industrial laundries because
it was present (8.5-170 ug/L) only in wastewater samples collected downstream
of these two industrial laundries.
Metro is currently evaluating removal of the contaminated sediments to
prevent them from being flushed into Elliott Bay. In addition, improvements
in the stormwater routing program to enhance in-line storage, and a
notification and control system to reduce source toxicant discharges when
overflows occur are under consideration (Romberg et al. 1987). Projected
source control measures are anticipated to reduce the number of CS0 events
from 50 events/yr to approximately 10 events/yr (Romberg and Sumeri 1988).
Projected stormwater separation measures are anticipated to reduce the
number of CS0 events to approximately 10 events/yr by the mid-1990s (Romberg
and Sumeri 1988).
3-2-2 Identification of Indicator Chemicals
Mercury, f 1 uoranthene, chrysene, butyl benzyl phthalate,
bis(2-ethylhexyl)phthalate, 4,4'-DDT, and total PCBs were selected as
indicator chemicals for the development of sediment recovery scenarios in
the Denny Way CS0 problem area. In addition, for the purpose of examining
sediment recovery times for a metal other than mercury, sediment recovery
scenarios were also developed for zinc. Table 2 identifies all of the
compounds determined to have an enrichment ratio greater than 1 for at least
34
-------
TABLE 2. IDENTIFICATION OF INDICATOR CHEMICALS IN DENNY UAY CSO OFFSHORE SEDIMENTS
Number of
Mumber of PTI
Largest
Historical
and Tetra Tech (1988)
Total No. of
~limber
Percent of
Enrichment
Analyses with
Analyses with
Analyses with
of Samples
Samples with
Ccnpound
Ratio
Ratio >1
Ratio >1
Ratio >1
Analyzed
Ratio >1
Metals
Cadniim
1.1
2
0
2
35
6
Lead
1.8
6
0
6
42
14
Silver
1.6
1
1
2
7
29
Zinc
2.1
14
0
14
42
33
Mercury
6.4
32
1
33
36
92
LPAH
Phenanthrene
66
8
0
8
24
33
Anthracene
42
6
0
6
25
24
Fluorene
58
4
0
4
21
19
Acenaphthene
26
1
0
1
21
5
Total LPAH
36
3
0
3
21
14
HP AH
Fluoranthene
36
10
0
10
25
40
Pyrene
14
6
0
6
25
24
BenzcK a)anthracene
8.2
8
0
8
23
35
Chrysene
19
10
0
10
23
43
Benzo(a)pyrene
4.7
6
0
6
23
26
Indeno(1,2,3-cd)pyrene
2.2
8
0
8
23
35
BenzcK g,h,i)perylene
2.1
7
0
7
22
32
Benzo AETa
••
1
--
1f2-dichlorobenzene
-»
0
DL > AET
--
1
--
1,2,4-trichlorobenzene
--
0
DL > AET
--
1
--
hexachIorobenzene
0
DL > AET
1
Fti thai ates
Butylbenzylphthalate
29
17
0
17
21
81
di-n-butyl phthalate
1.2
2
0
2
22
9
Dinethylphthalate
2.5
1
0
1
22
5
Bis (2-ethylhexyl) phthalate
28
13
0
13
20
65
Total phthalates
17
13
0
13
21
62
-------
TABLE 2. (Continued)
Pesticides/PCBs
4,4'-DDE 2 1
4,4'-DDD 6 1
4,4'-DOT 24 1
Total PCBs 20 27
Phenols
Phenol 4.5 4
Pentachlorophenol 5.6 2
0 1 2 50
DL > A£T 1 2 50
DL > AET 1 2 50
DL > AET 27 33 82
0 4 21 19
0 2 21 10
3 Method detection liait exceeded cleanup goal.
GJ
-------
one of the 42 stations. In addition, several chlorinated benzene compounds
are listed. A determination of whether concentrations of the chlorinated
benzenes exceeded the cleanup level could not be made. The only analysis
for these compounds resulted in a detection limit that exceed the cleanup
goal. Locations of the 42 sampling stations are presented in Figure 8.
Areal distributions of the indicator chemicals (except 4,4'-DDT) are pre-
sented in Figures 9-15. The contaminant 4,4'-DDT was measured at only
2 stations [NS-01 (PTI and Tetra Tech 1988) and S0032 (Romberg et al. 1984)].
An enrichment ratio of 24 was determined at Station S0032 but a ratio at
Station NS-01 could not be calculated because the method detection limit
exceeded the target cleanup level. Appendix A summarizes the data evaluated
to identify the indicator chemicals in the Denny Way CSO problem area.
3.2.3 Identification of a Sediment Accumulation Rate
Application of the Pb-210 age-dating method to samples collected in the
area offshore from the Denny Way CSO provided inconclusive results (Romberg
et al. 1987). However, Romberg et al. (1987) estimated a sediment accumula-
tion rate of 0.7 cm/yr by observation of a distinctive feature in a core
sample collected at Station 7 (see Figure 8). At Station 19, the closest
Metro station to the outfall, a sedimentation rate of 1.4 cm/yr was
determined by the same method. These estimated rates may have been
influenced by recent excavation and building activities in the area.
Therefore, the measured rates are assumed to be greater than those that
might have been obtained if the setting had been undisturbed (Romberg, P.,
7 March 1988, personal communication).
After implementation of source control, the sediment deposition rate
around the CSO would be expected to decrease and would depend on the degree
of source control applied. In the absence of CSO discharges, the Duwamish
River, whose thin lens surface plume clings to the eastern shore of Elliott
Bay, may become the primary source of particulates to the area. However, a
recent study indicated that directly beyond the sources, most (i.e.,
90 percent) of the suspended particulate matter from the Duwamish River
remains in suspension and is transported to the main basin of Puget Sound
within 5 days (Curl et al. 1987).
37
-------
meters
DENNY WAY
CSO OUTFALL
r.NS-01
•10041
•1603
• 22
•30A
•1606
•AO 60
• S
FORMER PIER 71
•C060 *1810
• 1612
Figure 8. Sampling station locations in the Denny Way CSO
problem area.
38
-------
600
feet
31 meters
100
200
n
• 2.0 \:,
• *2 4
•1.8
• 1.6
• 3.1
• 1.2
•0.45
• 1.2
• 1.5
• 2.7 *9.2 #1 9 Vl.O
•1-® *3'4 .2.6 .6,4 \
• *3.4 #64
•1.8 *2.8 #3.i £
•1.0 *1.1 #1.5 #49\.
•3.4
DENNY WAY
CSO OUTFALL
• 2.8
• 1.9
• 2.1
• 2.7
v ¦ \ FORMER PIER 71
Figure 9. Areal distribution of mercury concentrations in Denny Way
surficial sediments, corrected for background concentration
and normalized to the target cleanup goal (Cq/Cq).
39
-------
600
feet
meters
n
•o.64\;.
10.19 *0.87
• 0.72
• 0.86
>0.18
,0.44
0 22
~ 0.41
• 0.52
• 1.1 «0.90#19 lfc.0.48
•1'2 #V1 .1-1 .2,1
• 0.47 *1.0 90.94
*0.59 #1 2
0*3 o*55 #1"3 *10
•0 82 .1.9
•1-1 *1.0
DENNY WAY
CSO OUTFALL
• 0.28
• 0.75
• 1.6
>0.99
• 0.39
• 0.66
FORMER PIER 71
• 0.60
• 0.29
• 0.27
Figure 10. Areal distribution of zinc concentrations in Denny Way
surficiat sediments, corrected for background concentra-
tion and normalized to the target cleanup goal (Co /Cq').
40
-------
feet
H meters
• 5.9
•0.53
• 0.25 X-
•0.18
• 1.0
1.3 *4.0 #36 ljr.0.26
•0.27 •
19 *4.0 \:
• • *2.8
• *0.85 #1.1
• *0.14 •
0.41 V-.
•0.52
•0.39 si 5
• 0.04
•0.94
FORMER PIER 71
• 0.29
DENNY WAY
CSO OUTFALL
•0.36
Figure 11. Areal distribution of fluoranthene concentrations in Denny
Way surficial sediments, normalized to the target cleanup
goal (Qj/Qs).
41
-------
600
feet
1 meters
100
200
n
• 6.4 •
• 0.81
• 0.26
10.26
• 0.42
~ 0.36
• 0.85
•1.7 *3.6 #19
•0 M * *2.0 .2,9
• *2.9
• *1-0 *1.1
• *0.2 •
DENNY WAY
CSO OUTFALL
••<002
•0 34 V.
•0.86
• 0.49 #2.2
•0.09
FORMER PIER 71
Figure 12. Areal distribution of chrysene concentrations in Denny
Way surficial sediments, normalized to the target
cleanup goal (Cq/Cg).
42
-------
meters
DENNY WAY
CSO OUTFALL
FORMER PIER 71
Figure 13. Areal distribution of butyl benzyl phthaiate concentrations
in Denny Way surficial sediments, normalized to the
target cleanup goal (Cq/Cq).
43
-------
feet
meters
200
• •
• 0.57
• 0.71
• 4.6 N<;.
• 6.4
• 28 •
• 12
• 8.2 »19 #0.63
•6.5 »0.21
* «9.6
• *021 *11
• *0.42 •
DENNY WAY
CSO OUTFALL
• 2.3
•1.2
•0.26 * C18
•0.1
FORMER PIER 71
Figure 14. Areal distribution of bis(2-ethylhexyl)phthalate concen-
tration in Denny Way surficial sediments, normalized to
the target cleanup goal (Cq/Cg).
44
-------
600
feet
55) meters
100
200
• 13
n
• 11 •
• 3.2
• 2.0
• 1.2
• 1.3 %
11.2
•2.2
#5.9 #2.3 02 3
*3-9 #3'0« .82
• 15 • •<0.23
• •~•5 »0.92
• #1.7
DENNY WAY
CSO OUTFALL
3.0
• 20
• 1.3
•<0.23\V.'.
• 5.2
•16
>7.2 •^
• 0.06
• 3.9
• 3.7
FORMER PIER 71
• 0.02
>5.7
l 8.5
Figure 15. Areal distribution of total PCB concentrations in Denny
Way surficial sediments, normalized to the target
cleanup goal (C^/Cq).
45
-------
Background deposition rates in the area directly offshore from the
Denny Way CSO are not available. However, sedimentation rates derived from
excess Pb-210 in sediment cores collected from central Puget Sound shallow
bays ranged from 0.22 to 0.66 cm/yr (Carpenter et al. 1985). Because of the
inability to accurately predict a sedimentation rate in the area after
source control, sedimentation rates of 0.2 and 0.7 cm/yr were used in the
application of SEDCAM. Use of two sedimentation rates was expected to
provide a range of sediment recovery scenarios in this area. The lower rate
is conservative and results in the longest sediment recovery time estimates.
If source control measures substantially reduce the sediment discharged from
the Denny Way CSO, the lower sedimentation rate may reflect the deposition
process more closely than the higher rate. However, if the implementation
of source control reduces the contaminant load to the offshore sediments but
does not reduce the amount of particulate discharged than the higher
sedimentation rate may be appropriate.
3.2.4 Sediment Recovery Scenarios
Sedimentation rates of 0.2 cm/yr and 0.7 cm/yr and a mixing depth of 10
cm were selected for the model. The relationship between source control and
sediment recovery was evaluated for mercury, fluoranthene, chrysene, butyl
benzyl phthalate, bis(2-ethylhexyl)phthalate, 4,4'-DDT, and total PCBs.
These chemicals had the greatest enrichment ratios over the greatest area
for their respective chemical groups. Source loading and sediment accumula-
tion are assumed to be in steady-state. None of the indicator chemicals was
expected to display losses due to biodegradation or diffusion.
3.2.4.1 Effect of No Source Control--
Evaluation of the effect of not controlling sources is only meaningful
for ongoing sources where the relationship between source loading and
sediment accumulation is not in steady-state. For sources where the
relationship is in steady-state, as was assumed for the Denny Way CSO, the
absence of source control will result in no change in the level of problem
chemicals in surface sediments.
46
-------
3.2.4.2 Effect of Complete Source Elimination--
The predicted effect of complete source elimination on the recovery
time of the indicator chemicals is based on a single enrichment ratio for
each indicator chemical (Figure 16). Each enrichment ratio used to project
a recovery time in Figure 16 is based on the maximum concentration observed
in the surface sediments for the specific indicator chemical. At a
sedimentation rate of 0.2 cm/yr, it is estimated that acceptable surface
sediment concentrations of mercury will not be achieved before 90 yr after
loading has been eliminated (100 percent source control implementation).
Zinc on the other hand could recover in approximately 40 yr. Based on the
maximum concentrations observed for each of the other indicator chemicals,
it is also predicted that acceptable surface sediment concentrations of
these chemicals will be achieved between 135 and 180 yr (Figure 16). In
contrast, given 100 percent source control and a sedimentation rate of
0.7 cm/yr, acceptable surface sediment concentrations of mercury are
expected to be achieved in approximately 27 years (Figure 16). Zinc could
recover in 12 yr. At this sedimentation rate concentrations of the other
indicator chemicals are predicted to be at acceptable levels between 37 and
52 yr.
Projection of sediment recovery scenarios using enrichment ratios based
on the maximum concentration is conservative and results in maximum recovery
time estimates. In some cases, the maximum concentration occurs at a hot-
spot in the problem area. That is, the maximum concentration is signifi-
cantly greater than the concentrations observed at surrounding stations.
Therefore, it can be informative to develop recovery time scenarios using
enrichment ratios that may be more representative of the overall contamina-
tion in the area. Butyl benzyl phthalate displayed the greatest enrichment
ratio over the greatest area in the Denny Way CS0 problem area. Sediment
recovery times at 100 percent source control were estimated for butyl benzyl
phthalate using the five largest enrichment ratios observed in the problem
area. These recovery times are presented in Figure 17 and suggest that in
the absence of sediment remediation, sediment contamination will persist
over a large area for decades.
47
-------
a.)
c5?
5
H
<
CC
H
Z
LU
s
X
o
£
z
LU
100-1
SEDIMENTATION RATE = 0.2 cm/yr
10-
MERCURY
b.)
100
SEDIMENTATION RATE = 0.7 cm/yr
10-
FUJORANTHENE
BUTYL BENZYL PHTHALATE
TOTAL PCBs
CHRYSENE
BIS(2-ETHYLHEXYL)PHTHALATE
. 4,4-DDT
FLUORANTHENE
BUTYL BENZYL PHTHALATE
TOTAL PCB>
CHRYSENE
BIS(2-ETHYLHEXYL)PHTHALATE
20 30 40
SEDIMENT RECOVERY TIME (YR)
* Mercury and zinc enrichment ratios - C0'/Cq.
Figure 16. Sediment recovery model results for the Denny Way problem area:
enrichment ratio based on maximum concentration vs. sediment
recovery given 100 percent source control for sedimentation rates
of 0.2 cm/yr (a) and 0.7 cm/yr (b).
48
-------
a.)
DC
o
UL
H
<
cc
H
Z
UJ
2
z
o
E
z
tii
cJ?
UJ
H
<
_l
<
X
H
Z
Q.
>
N
Z
Ui
03
>¦
h-
3
CD
100-1
SEDIMENTATION RATE = 0.2 cm/yr
10-
b.)
100-,
: SEDIMENTATION RATE = 0.7 cm/yr
10-
STATION 28
STATION 27
STATION 17
STATION 20
STATION 19
STATION 28
STATION 27
STATION 17
STATION 20
STATION 19
SEDIMENT RECOVERY TIME (YR)
Figure 17. Sediment recovery model results using five concentrations of butyl benzyl
phthalate found in the Denny Way problem area: enrichment ratio vs.
sediment recovery time given 100 percent source control for sedimentation
rates of 0.2 cm/yr (a) and 0.7 cm/yr (b).
49
-------
3.2.4.3 Source Control Required for Long-Term Sediment Recovery--
The degree of source control required for long-term sediment recovery
is directly proportional to the enrichment ratio for sources that are in
steady-state. The relationship between source loading and sediment
accumulation is assumed to be in steady-state. Thus, regardless of
sedimentation rate, 84 percent of the mercury and more than 94 percent of
the total PCBs, fluoranthene, butyl benzyl phthalate, bis(2-ethylhexyl)phtha-
late, and chrysene presently being supplied to the Denny Way CSO problem
area would have to be eliminated to maintain acceptable sediment concentra-
tions after sediment remediation. These predictions are based on each
contaminant's level of exceedance of the target cleanup goal, and therefore
do not take into account any recent reduction in contaminant loading to the
area.
3.3 DUWAMISH RIVER SLIP 4
3.3.1 Source Summary
Elevated concentrations of PCBs have been measured in the surficial
sediments in Slip 4 (Figure 18). Samples collected by U.S. EPA from the
head of Slip 4 in 1982 and 1983 exhibited PCB concentrations between 1,600
and 5,600 ug/kg. Five drains discharge into Slip 4 [1-5 storm drain (SD),
Slip 4 CSO/SD #117, Slip 4 SD, Georgetown Flume, and East Marginal Pump
Station CSO W043]. Descriptions of each drain are presented in Table 3. In
1984, Metro collected sediment samples from the four storm drains discharging
into Slip 4 to determine the source of the PCB contamination in offshore
sediments (Sample, T., 23 October 1987, personal communication). The
results indicated that three of the four storm drains (i.e., Georgetown
Flume, Slip 4 CSO/SD #117, and Slip 4 SD) were contaminated with PCBs
(Figure 18). PCB levels were measured at 17,900-160,000 ug/kg in the
Georgetown Flume, 103,000 ug/kg in Slip 4 CSO/SD, and 19,500 ug/kg in Slip 4
SD. These concentrations exceed the average level reported for urban street
dust from eight cities in the U.S. (770 ug/kg; Galvin and Moore 1982) by 2-3
orders of magnitude. PCB concentrations in the sediments collected from the
50
-------
South Warsaw Street
;90*0'^
UPS™™*
SJrW*"0*
sjii
-------
TABLE 3. DESCRIPTION OF DRAINS
DISCHARGING INTO SLIP 4
Outfall
Name Diameter (in)
Drainage
Basin Area
(ac)
Description of
Service Area
1-5 SDa
66
30
Drains approximately 1.5
mi of 1-5 between S.
Dawson and S. Myrtle
Streets and part of
Georgetown area.
Georgetown Flume
60
Open wood flume originally
installed to discharge
cooling water from Seattle
City Light's Georgetown
Steam Plant. Exact
service area unknown.
Numerous other side
connections have been
identified. All side
connections have been
plugged by Seattle City
Light.
Slip 4 CSOb/SD #117
24
150 (SD)
74.6 (CSO)
Drains the north end of
King County Airport (i.e.,
Boeing Field).
Slip 4 SD
60
170
Serves portions of King
County Airport.
East Marginal Pump
Station CSO W043
36
318
Emergency sewer overflow
for Metro pump station.
a SD - Storm drain,
b CSO - Combined sewer overflow.
52
-------
1-5 SD were 2-3 orders of magnitude lower than the concentrations measured
for the other three storm drains, and did not exceed levels reported for
urban street dust. Therefore, 1-5 SD has not been considered a source of
PCBs to Slip 4.
Seattle City Light (City Light) collected sediment samples in 1984 from
various locations along the Georgetown Flume to trace contamination
(Figure 18). The highest PCB concentration (1,800 ug/kg) was found in
sediments collected from the downstream side of the tunnel in the flume
(Figure 18) (Geissinger, L., 9 December 1987, personal communication). PCB
contamination was subsequently traced to a City Light property at the head
of the flume where soil contained PCBs in concentrations as high as
91,000,000 ug/kg. These soils were excavated to depths of 4-6 ft to attain
cleanup levels of 150-200 ug/kg (Geissinger, L., 9 December 1987, personal
communication) and contaminated sediment deposits were removed from the
flume. City Light has plugged all side connections to the flume to prevent
future contamination, and sediment traps were installed in the flume to
collect sediments prior to discharge to Slip 4. City Light plans to fill
the flume to prevent its use in the future (Geissinger, L., 9 December 1987,
personal communication).
The source of PCBs in Slip 4 CSO/SD #117 has not been identified to
date. During cleanup activities in Georgetown Flume, City Light collected
sediment samples from Slip 4 CSO/SD and found PCB concentrations as high as
10,000 ug/kg (Smukowski, D.# 14 December 1987, personal communication).
The Boeing Company worked with Metro to trace contamination in this storm
drain line, which crosses their property. However, they were not able to
locate a PCB source in the area. In 1985, Boeing removed contaminated
sediments from the Slip 4 CSO/SD. This drain has since been rerouted to the
pump station on the Slip 4 SD system and discharges to Slip 4 via this 60-in
line (Smukowski, D., 14 December 1987, personal communication).
PCB contamination has not been fully investigated in the Slip 4 SD
system to date. Consequently, it is not known whether there is an ongoing
source of PCBs in this drainage basin.
53
-------
3.3.2 Identification of Indicator Chemicals
Chromium, fluoranthene, PCBs, and 4,4'-DDD were selected as indicator
chemicals to develop sediment recovery scenarios in the Duwamish River Slip
4. Compounds with enrichment ratios greater than 1, based on maximum
concentrations, are presented in Table 4. Compounds that had a method
detection limit greater than the target cleanup goal are also identified.
Locations of the sampling stations in the slip are shown in Figure 19.
Areal distributions of the indicator chemicals are presented in Figures 20-
23. Data were not available for all indicator chemicals at all sampling
stations.
3.3.3 Sediment Accumulation Rate
Determination of a sediment accumulation rate for Slip 4 was difficult
because of lack of available sediment core data and the complexity of the
deposition process in riverine systems. Measurement of sedimentation rates
through Pb-210 dating in the Duwamish River has not been performed to date.
The use of alternative methods to estimate sedimentation rates (i.e., core
discontinuities, dredging records, bathymetric records) also proved to be
unsuccessful primarily because of insufficient information. A rough
estimate of the sediment accumulation rate was determined using unpublished
sediment core data collected by Ecology in 1985 (Schlender, M., 16 April
1985, personal communication). Three sediment samples were collected in the
slip at low tide to depths of 6, 12, and 18 in (Brugger, G., 15 March 1988,
personal communication). One sample (#102) was taken directly off of the
Georgetown Flume outfall, a second sample (#109) was collected on a sandbar
approximately 20 ft off of the flume outfall, and the third sample (#105)
was taken approximately 20 ft from the Slip 4 CS0/SD #117 outfall. The data
from the analysis of the top 6 in of these samples for PCBs are presented in
Table B-l. PCB concentrations in all three samples increased with depth,
with the maximum concentration occurring at 18 in.
One technique used to calculate a sediment deposition rate entailed
dividing 18 in (PCB contamination known to be present at this depth) by the
number of years that elapsed between the time the samples were collected and
54
-------
TABLE 4. IDENTIFICATION OF INDICATOR CHEMICALS IN DUWANISH RIVER SLIP 4 SEDIMENTS
Nuiter of
Number of
Largest
Historical
Tetra Tech
Total No. of
Nunber
Percent of
Enrichment
Analyses with
Analyses with
Analyses with
of Samples
Sanples with
Compound
Ratio
Ratio >1
Ratio >1
Ratio >1
Analyzed
Ratio >1
METALS
Chrtniua
3.2
4
1
5
6
83
Zinc
1.7
2
1
3
e
50
Lead
3.0
1
0
1
6
17
Mercury
1.5
0
1
1
6
17
LPAH
Acenaphthene
2.0
1
0
1
3
33
Phenanthrene
1.5
1
0
1
3
33
Anthracene
1.0
2
0
2
3
67
HPAH
Fluor ant bene
2.5
2
0
2
3
67
Pyrene
1.5
1
0
1
3
33
Chrysene
1.4
2
0
2
3
67
Indeno(1,2,3-cdJpyrene
1.8
0
1
1
3
33
Dibenzo(a,h)anthracene
1.2
0
1
1
3
33
Phthalates
Butyl benzylphthalate
4.6
0
Lh
1
3
33
Bis(2-ethylhexyl)phthalate
2.1
1
**0
1
2
50
Miscellaneous
Pentachlorophenol
—
—
OL > LAET*
—
1
—
Benzyl Alcotol
—
—
DL > LAET
—
1
—
1,2-dichlorobenzene
—
DL > LAET
OL > LAET
—
3
—
1,2,4-tHchlorobenzene
—
DL > LAET
DL > LAET
—
3
--
Hexachlorabenzene
—
0L » LAET
OL > LAET
—
3
—
Pesticides/PCBs
4,4"-DOE
6
0
1
1
3
33
4.4'-0DD
19
0
1
1
3
33
4,4'-00T
—
DL > LAET
OL > LAET
—
3
—
Total PCBs
46
5
1
6
6
100
a Method detection limit exceeded cleanup 90a!.
k Data rejected.
-------
VACATED S. FONTANELLE STREET
SL-01
DR-08
SL-02
E19A#
Figure 19. Location of sampling stations in Slip 4.
56
-------
VACATED S. FONTANELLE STREET
12(1962)
43(1963)
VACATED S. WEBSTER STREET
Figure 20. Areal distribution of total PCB concentrations in Slip 4
sediments, normalized to the target cleanup goal (C0/CG).
57
-------
VACATED S. FONTANELLE STREET
VACATED S. WEBSTER STREET
Figure 21. Areal distribution of chromium concentrations in Slip 4
sediments, normalized to the target cleanup goal (Cq/Cg).
58
-------
VACATED S. FONTANELLE STREET
VACATED S. WEBSTER STREET
Figure 22. Areal distribution of fluoranthene concentrations in Slip 4
sediments, normalized to the target cleanup goal (C0/CG).
59
-------
VACATED S. FONTANELIE STREET
VACATED S. WEBSTER STREET
DL>LAET
(1963)
DL>LAET
Figure 23. Areal distribution of 4,4'-DDD concentrations in Slip 4
sediments, normalized to the target cleanup goal (Cq/Cg).
60
-------
the year established as being the earliest possible date that PCBs could
have been handled in the vicinity of Slip 4. The marketing of PCBs under the
tradename Aroclor began in 1930 (Erickson 1986). Therefore, one estimated
sedimentation rate in Slip 4 is 0.8 cm/yr. If PCBs were not handled in or
around Slip 4 until some time after 1930, the estimated deposition rate of
0.8 cm/yr is an underestimate. In addition, if PCB contamination is present
at a depth greater than 18 in (which is possible since the maximum PCB
concentration was observed at 18 in), then the estimated rate of accumulation
is also an underestimate. Dredging is not known to have been conducted at
the locations where the three samples were collected based on available
dredging permits (Tetra Tech 1988a). However, at least one dredging
operation has occurred in the slip since 1930 (Tetra Tech 1988a), which
could have influenced the deposition process. The estimated sedimentation
rate of 0.8 cm/yr represents a minimum accumulation rate. If the sediments
accumulate at a faster rate, the sediments are expected to recover in a
shorter time period than is predicted. In addition, a sedimentation rate of
2.0 cm/yr was applied to the Slip 4 problem area to illustrate the model's
sensitivity to this parameter.
3.3.4 Sediment Recovery Scenarios
Sedimentation rates of 0.8 and 2.0 cm/yr and a mixing depth of 10 cm
were selected to represent the problem area. Chromium, fluoranthene, PCBs,
and 4,4'-ODD where chosen as indicator chemicals and the maximum concentra-
tion of each contaminant observed in the problem area was applied in the
development of the sediment recovery scenarios. Chromium, fluoranthene, and
PCBs where selected because they displayed the greatest enrichment ratios
over the greatest area. The contaminant 4,4'-DDD was selected as an
indicator chemical even though two of the three analyses resulted in a method
detection limit greater than the target cleanup goal. None of the chemicals
were assumed to display losses due to biodegradation or diffusion. The
steady-state approximation was used to characterize the relationship between
source loading of chromium, fluoranthene, PCBs, and 4,4'-DDD and sediment
accumulation.
61
-------
3.3.4.1 Effect of No Source Control--
An evaluation of the effect of not controlling sources is only
meaningful for ongoing sources where the relationship between source loading
and sediment accumulation is not in steady-state. For sources where the
relationship is in steady-state, as was assumed for Slip 4 sources, the
absence of source control will result in no change in the concentration of
problem chemicals in surface sediments.
3.3.4.2 Effect of Complete Source Elimination--
The predicted effect of completely eliminating source input to Slip 4
on the recovery time of sediments contaminated with chromium, fluoranthene,
PCBs, and 4,4'-DDD is based on a single enrichment ratio for each of these
indicator chemicals (Figure 24). Each enrichment ratio used to project a
recovery time in Figure 24 is based on the maximum concentration of the
specific indicator chemical observed in the surface sediments. At a
sedimentation rate of 0.8 cm/yr and 100 percent source control, the model
predicts that the concentration of chromium and fluoranthene will reach
acceptable levels between 11 and 15 yr (Figure 24a). Based on the only
enrichment ratio available for 4,4'-DDD, the concentration of 4,4'-DDD will
reach an acceptable level in approximately 37 yr at a sedimentation rate of
0.8 cm. However, given the level of PCB contamination in the area, without
sediment remedial actions, acceptable levels of PCBs in Slip 4 are not
expected to be achieved for 48 yr (Figure 24a). In contrast, at a sedimen-
tation rate of 2.0 cm/yr, it is estimated that acceptable surface sediment
concentrations of PCBs could be achieved 19 yr after loading has been
eliminated (Figure 24b). Based on the maximum concentrations observed for
each of the other indicator chemicals, it is predicted that acceptable
surface concentrations of these chemicals will be achieved between 5 and 15
yr.
Projecting sediment recovery scenarios using enrichment ratios based on
the maximum concentration is conservative and results in maximum recovery
time estimates. In some cases, the maximum concentration of an indicator
chemical occurs at a hotspot 1n the area. That is, the maximum concentra-
62
-------
cF
<
cc
LU
2
X
o
DC
z
LU
a.)
100 —,
10-
SEDIMENTATION RATE = 0.8 cm/yr
R-OURANTHENE
4.4--DDD
-TOTAL PCBs
b.)
1001 SEDIMENTATION RATE = 2.0 cm/yr
10-
- TOTAL PCBs
FLOURANTHENE
4.4'-ODD
h CHROMIUM
SEDIMENT RECOVERY TIME (YR)
Figure 24. Sediment recovery model results for Slip 4: enrichment ratios
based on maximum concentrations vs. sediment recovery time
given100 percent source control for sedimentation rates of
0.8 cm/yr (a) and 2.0 cm/yr (b).
63
-------
tion is significantly greater at one station than at adjacent stations.
Therefore, it can be informative to develop recovery time scenarios using
enrichment ratios that may be more representative of the overall contamina-
tion in the area. PCBs displayed the greatest enrichment ratio over the
greatest area in Slip 4. Sediment recovery times at 100 percent source
control were estimated for PCBs using the enrichment ratios from all five
stations in Slip 4 for sedimentation rates of 0.8 cm/yr and 2.0 cm/yr.
These estimated recovery times are presented in Figure 25.
3.3.4.3 Source Control Required for Long-Term Sediment Recovery--
The degree of source control required for long-term sediment recovery
is directly proportional to the enrichment ratios for sources that are in
steady-state. The relationship between source loading and sediment
accumulation is assumed to be in steady-state. Therefore, to maintain
acceptable sediment concentration of these chemicals after sediment
remediation, 98 percent of the PCBs, 95 percent of the 4,4'-DDD, 69 percent
of the chromium, and 60 percent of the fluoranthene presently supplied to
the slip must be eliminated.
64
-------
a.)
100 1
SEDIMENTATION RATE = 0.8 cm/yr
-------
4.0 MODEL LIMITATIONS AND RECOMMENDATIONS
SEDCAM uses a mass balance equation to predict the sediment concentra-
tion of contaminants in relation to source loading, sedimentation rate,
mixing, biodegradation, and diffusive loss across the sediment-water
interface. Several factors limit the model's ability to precisely reproduce
real-world conditions. Some of the limitations are inherent in the
formulation of the model while others are based on the lack of available
data. The most significant limitations of the model include the following:
¦ Difficulty in evaluating recent sediment accumulation rates
¦ Accurate quantification of chemical-specific decay rates due
to biodegradation and diffusion
¦ Assumption that mixing in the surface mixed layer occurs
instantaneously
¦ Availability of source loading and ancillary data
¦ Appropriateness of the steady-state assumption.
Depositional patterns and accumulation rates of sediments in embayments
and riverine slips vary in time and by location. The rate of sediment
deposition in the Denny Way CSO problem area may be substantially reduced by
the implementation of source control measures. Sedimentation in Slip 4 is
expected to occur in irregular intervals with the majority of sediment being
deposited during storm events. The application of SEDCAM 1s more appro-
priate in areas where sedimentation rates are more uniform. However, the
average rates used in this analysis provide some useful indications of the
potential for sediment recovery.
66
-------
In situ degradation and diffusion, like sediment dilution and the
mixing process, can effectively reduce sediment contaminant concentrations
over time, and thus are important when estimating recovery times. However,
data that accurately quantify chemical-specific decay rates due to biodegra-
dation and diffusion are not readily available. The combined first-order
decay rate constants selected resulted in upper estimates of recovery
times. Because the successful application of SEDCAM depends, in part, on
decay rate constants that reflect the real decay process as closely as
possible, the values assigned should be revised if and when empirical data
become available.
The formulation of the model is based on the assumption that mixing in
the surface mixed layer occurs instantaneously. This assumption is a
simplification that allows for an analytical solution to the differential
equation describing the variation in contaminant concentration in the mixed
layer with time.
Characterization of the volumes of contaminants supplied by different
sources is required to accurately predict sediment recovery scenarios. Few
detailed assessments of toxicant loading from sources have been attempted
primarily because chemistry data from a large number of CSO events would be
required to generate a representative average concentration for each
contaminant. The concentration of a problem chemical in recently deposited
sediments following source control is difficult to determine. The informa-
tion necessary to determine the concentration is not always available. The
steady-state assumption (i.e., that the input rate of the contaminant
equals the removal rate of the contaminant prior to source control) is a
simplification that eliminates the need to specify information that is not
available. However, this assumption may not reflect the true process and
may result in an underestimate or overestimate of the concentration in
recently deposited sediments, depending on whether source loading has
increased or decreased recently. The steady-state assumption is probably
most questionable when applied to environmental settings, such as Slip 4,
where the bulk of the sediment accumulated yearly can be deposited in a
matter of days.
67
-------
During the Commencement Bay Nearshore/Tideflats Feasibility Study
(Tetra Tech in preparation), a sensitivity analysis was performed to
evaluate the effect of changing the depth of the mixed layer used in the
sediment recovery time calculations. A mixed layer depth of 20 cm was used
in the sensitivity analysis, representing the maximum value of all mixed
layer measurements. Increasing the mixing depth from 10 to 20 cm has the
same effect as reducing the sedimentation rate used by 50 percent.
Increasing the mixed layer depth or decreasing the sedimentation rate would
lengthen the recovery time of the sediments. Similarly, decreasing the
mixed layer depth or increasing the sedimentation rate would reduce the
length of time required for contaminant concentrations in surficial sediments
to be reduced to an acceptable level (i.e., the target cleanup goal).
SEDCAM is a useful tool to assess the relationship between source
control and the recovery of contaminated sediments. Several factors have
been identified that would facilitate the refinement of the model:
¦ Improved contaminant loading data
¦ Well-characterized sediment accumulation rates and sediment
depositional patterns
¦ Applicable chemical-specific decay rates due to biodegradation
and diffusion
¦ Validation of sediment recovery predictions through monitor-
ing.
In spite of the limitations associated with the formulation and
application of SEDCAM, the following conclusions can be drawn:
¦ Source elimination alone is not expected to result in
sediment recovery in either the Denny Way CSO problem area or
Slip 4 within a reasonable timeframe because of the current
level of contamination
68
-------
¦ Following sediment remediation, source control levels of 94
percent or greater in the Denny Way CSO and 98 percent or
greater in Slip 4 will be required to maintain acceptable
sediment quality in each problem area.
69
-------
REFERENCES
Armstrong, J.W., R.H. Thorn, K.K. Chew, B. Arpke, R. Bohn, J. Glock, R.
Hieronymus, E. Hurlbert, K. Johnson, B. Mayer, B. Stevens, S. Tettlebach,
and P. Waterstrat. 1978. The impact of the Denny Way combined sewer
overflow on the adjacent flora and fauna in Elliott Bay, Puget Sound,
Washington. Municipality of Metropolitan Seattle, Seattle, WA. 102 pp.
Baker, E.T., G.A. Cannon, and H.C. Curl, Jr. 1983. Particle transport
processes in a small marine bay. J. Geophys. Res. 88:9661-9669.
Brugger, G. 15 March 1988. Personal Communication (phone by Ms. Lynne M.
Kilpatrick-Howard). Klienfelder and Associates, Bellevue, WA.
Carpenter, R., M.L. Peterson, and J.T. Bennet. 1985. Pb-derived sediment
accumulation and mixing rates for the greater Puget Sound Region. Mar.
Geol. 64:291-312.
Chapman, P.M., G.A. Vigers, M.A. Farrell, R.N. Dexter, E.A. Quinlan, R.M.
Kocan, and M.L. Landolt. 1982. Survey of biological effects of toxicants
upon Puget Sound Biota. I: Broad scale toxicity survey. NOAA Technical
Memorandum 0MPA-25. National Oceanic and Atmospheric Administration,
Boulder, CO. 98 pp.
Comiskey, C.E., T.A. Farmer, C.C. Brandt, and G.P. Romberg. 1984. Toxicant
Pretreatment Planning Study Technical Report C2: Puget Sound benthic
studies and ecoogical implications. Municipality of Metropolitan Seattle,
Seattle, WA. 373 pp.
Crecelius, E. 7 January 1988. Personal Communication (letter to Mr. Ted
Turk.) Battelle Marine Research Laboratory, Pacific Northwest Division,
Sequim, WA.
Curl, H.C., E.T. Baker, T.S. Bates, G.A. Cannon, R.A. Feely, T.L. Geiselman,
M.F. Lamb, P.P. Murphy, D.J. Pashinski, A.J. Paulson, and D.A. Tennant.
1987. Contaminant transport from Elliott and Commencement Bays. Final
Report. Prepared for U.S. Environmental Protection Agency Region X, Puget
Sound Estuary Program. NOAA/Pacific Marine Environmental Laboratory,
Seattle, WA.
Erickson, M.D. 1986. Analytical chemistry of PCBs. Butterworth Publishers,
Stoneham, MA.
EVS and Tetra Tech. In preparation. Elliott Bay Action Program: develop-
ment of a monitoring approach. EVS Consultants, Vancouver, BC and Tetra
Tech, Inc., Bellevue, WA.
Galvin, D.V. and R.K. Moore. 1982. Toxicants in urban runoff. Metro
Toxicant Program Report No. 1. Municipality of Metropolitan Seattle,
Seattle, WA. 160 pp.
70
-------
Geissinger, L. 9 December 1987. Personal Communication (phone by Ms. Beth
Schmoyer). Seattle City Light, Seattle, WA.
Lavelle, J.W. 6.J. Massoth, and E.A. Crecelius. 1986. Accumulation rates
of recent sediments in Puget Sound, Washington. Mar. Geol. 72:59-70.
Lyman, W.J., W.F. Reehl, and D.H. Rosenblatt. 1982. Handbook of chemical
property estimation methods. McGraw-Hill Book Company, New York, NY.
Malins, D.C., B.B. McCain, D.W. Brown, A.K. Sparks, and H.O. Hodgins. 1980.
Chemical contaminants and biological abnormalities in central and southern
Puget Sound. NOAA Technical Memorandum OMPA-2. National Oceanic and
Atmospheric Administration, Boulder, CO. 295 pp.
PTI and Tetra Tech. 1988. Elliott Bay Action Program: analysis of toxic
problem areas. Draft Report. Prepared for the Puget Sound Estuary Program.
PTI Environmental Services, Bellevue, WA and Tetra Tech, Inc., Bellevue, WA.
PTI and Tetra Tech. In preparation. Elliott Bay Action Program: develop-
ment of a revised action plan. PTI Environmental Services, Bellevue, WA and
Tetra Tech, Inc., Bellevue, WA.
Romberg, G.P., S.P. Pavlou, R.F. Shokes, W. Horn, E.A. Crecelius, P. Hamilton,
J.T. Gunn, R.D. Muench, and J. Vinelli. 1984. TPPS Technical Report CI:
Presence, distribution, and fate of toxicants in Puget Sound and Lake
Washington. Toxicant Pretreatment Planning Study. METRO Toxicant Program
Report No. 6A. Water Quality Division. 231 pp.
Romberg, G.P., D. Healy, and K. Lund. 1987. Toxicant reduction in the
Denny Way combined sewer system. Municipality of Metropolitan Seattle,
Seattle, WA.
Romberg, P. 7 March 1988. Personal Communication (phone by Dr. Jean
Jacobyj. Municipality of Metropolitan Seattle, Seattle, WA.
Romberg, P., and A. Sumeri. 1988. Sediment capping at the Denny Way CSO.
Presented at the First Annual Meeting on Puget Sound Research, 18-19 March
1988, Puget Sound Water Quality Authority, Seattle, WA.
Sample, T. 23 October 1987. Personal Communication (data from Duwamish
industrial nonpoint source investigation provided to Tetra Tech, Inc.,
Bellevue, WA). Municipality of Metropolitan Seattle, Seattle, WA.
Schlender, M. 16 April 1985. Personal Communication (memorandum to Mr. G.
Brugger, Washington Department of Ecology, Redmond, WA). Washington
Department of Ecology, Olympia, WA.
Smukowski, D. 14 December 1987. Personal Communication (phone by Ms. Beth
Schmoyer). Boeing Company, Seattle, WA.
71
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Tetra Tech. In preparation. Commencement Bay Nearshore/Tideflats Feasi-
bility Study. Tetra Tech, Inc., Bellevue, WA.
Tetra Tech. 1986. Development of sediment quality values for Puget Sound.
Final Report. Prepared for Resource Planning Associates and U.S. Army
Corps of Engineers, Seattle District, for the Puget Sound Dredge Disposal
Analysis and Puget Sound Estuary Programs. September 1986. 128 pp. +
appendices.
Tetra Tech. 1987a. Commencement Bay Nearshore/Tideflats Feasibility
Study: assessment of the potential success of source control. Draft
Report. Prepared for the Washington State Department of Ecology. Tetra
Tech, Inc., Bellevue, WA.
Tetra Tech. 1987b. Commencement Bay Nearshore/Tideflats Feasibility
Study: development of sediment criteria. Final Draft Report. Prepared for
the Washington State Department of Ecology and U.S. Environmental Protection
Agency. Tetra Tech, Inc., Bellevue, WA.
Tetra Tech. 1988a. Elliott Bay Action Program: evaluation of potential
contaminant sources. Draft Report. Prepared for the Puget Sound Estuary
Program. Tetra Tech, Inc., Bellevue, WA.
Tetra Tech. 1988b. Elliott Bay Action Program: evaluation of sediment
remedial alternatives. Draft Report. Prepared for the Puget Sound Estuary
Program. Tetra Tech, Inc., Bellevue, WA.
Tetra Tech. 1988c. Elliott Bay Action Program: the relationship between
source control and recovery of contaminated sediments in two problem areas.
Prepared for U.S. Environmental Protection Agency Region X, Office of Puget
Sound, Seattle, WA. Tetra Tech, Inc., Bellevue, WA.
Tetra Tech. 1988d. Elliott Bay revised action program: development of a
storm drain monitoring approach. Draft report. Prepared for the Puget
Sound Estuary Program. Tetra Tech, Inc., Bellevue, WA. 93 pp. + appendices.
Tomlinson, R.D., B.N. Bebee, A.A. Heyward, S.G. Murger, R.G. Swartz, S.
Lazoff, D.E. Spyridakis, M.F. Shepard, R.M. Thorn, K.K. Chew, and R.R.
Whitney. 1980. Fate and effects of particulates discharged by combined
sewers and storm drains. U.S. Environmental Protection Agency, Washington,
DC.
U.S. Environmental Protection Agency. 1982-1983. Organic Analyses for
Duwamish River Surveys. Unpublished data.
Vogel, T.M., and P.L. McCarty. 1985. Biotransformation of tetrachloro-
ethylene to trichloroethylene, dichloroethylene, vinyl chloride, and carbon
dioxide under methanogenic conditions. Appl. Environ. Microbiol. 49: 1080-
1083.
72
-------
APPENDIX A
DENNY WAY CSO PROBLEM AREA
SEDIMENT CONTAMINANT DATA
-------
TABLE A-l. CONCENTRATION OF INORGANICS IN DENNY WAY CSO OFFSHORE SEDIMENTS
(mg/kg DRY WEISHT = ppm)
Survey Station Sample Rep Antimony Arsenic Beryllium Cadmium Chromium Copper Iron
PTI and
Tetra Tech
1988 NS-01 NS-01
Mai Ins et
al. 1980 10041 10041
Romberg
et al.
1984
23.9
4.9
1.14
6.5
El 04
251
58.8
29000
1406
1406
11.9
108.5
1512
1512
12.5
53.5
1603
1603
16.7
113
1606
1606
10.6
45.5
1612
1612
15
58
1706
1706
12.3
52
1810
1810
11.5
70
A060
A060
0.87
0.5
0.79
2.8
39
94
11000
B060
B060
1.3
12
1.1
1.5
50
140
32000
C060
C060
U0.03
44
0.89
1.5
51
61
24000
S0032
S0032
0.45
9.3
0.33
0.86
52
49
18000
Romberg
et al .
1987
BC-09
1
0.2
35
BC-33
2
0.6
60
BC-26
3
1.0
68
BC-19
4
1.1
73
BD-17
5
2.4
72
BC-25
6
1.1
72
BC-30
7
2.4
102
BC-22
8
2.0
109
BC-18
9
1.7
101
BC-16
10
2.3
92
BD-13
11
1.6
70
B0-10
12
1.9
86
BC-28
13
0.5
58
BC-32
14A
0.6
55
BC-23
15
0.5
42
BC-29
16
1.7
116
BC-21
17
2.6
132
BC-17
18
3.2
140
BD-15
19
01
2.8
212
BD-15
19
02
3.4
147
B0-15
19
Mean
3.1
179
B0-12
20
2.7
162
BD-09
21
2.3
112
BD-08
22
2.4
106
BD-07
23
2.3
94
BC-Z4
24
1.9
70
BC-31
25A
1.6
90
BC-27
26A
0.8
609
BD-16
27
3.2
264
BD-14
28
6.1
302
BO-18
30A
1.8
87
A-l
-------
TABLE A-l. (Continued)
Survey
Station Sample Rep
Lead
Manganese
Nickel
Selenium
Silver
Thai 11 un
Zinc
Mercury
PTI and
Tetra Tech
1988
NS-01
NS-01
217
E525
43.5
U0.11
E8.27
E158
E0.405
Mai 1ns
1980
10041
10041
74.3
3.8
97.8
1.1
Romberg
et al.
1984
1406
1406
149.5
155
1512
1512
74
105
1603
1603
530
433.3
1606
1606
68.5
118
1612
1612
94
115
1706
1706
115
193.3
1810
1810
101
120
A060
A060
220
220
54
0.07
0.72
U0.007
210
0.71
8060
B060
120
280
58
0.65
1.2
U0.015
140
U0.012
C060
C060
110
290
63
0.02
0.89
U0.01
180
U0.007
S0032
S0032
120
200
38
U0.2
1.9
U0.1
100
0.06
Romberg
et al.
1987
BC-09
1
48
150
0.49
BC-33
2
78
232
0.59
BC-26
3
111
205
0.66
BC-19
4
147
179
0.69
80-17
5
176
376
0.76
BC-25
6
136
234
0.88
8C-30
7
256
271
0.97
BC-22
8
246
271
1.2
BC-18
9
199
260
1.2
BC-16
10
196
294
1.0
B0-13
11
124
319
0.58
80-10
12
193
224
1.2
BC-28
13
84
187
0.42
BC-32
14A
97
143
0.47
BC-23
15
95
165
0.23
BC-29
16
241
241
0.57
BC-21
17
398
273
1.8
BC-17
18
398
374
0.99
BD-15
19
01
340
248
2.2
BD-15
19
02
407
307
1.1
BD-15
19
Mean
373
277
1.7
B0-12
20
267
257
1.1
BD-09
21
304
268
1.7
BD-08
22
148
262
1.1
BD-07
23
260
258
0.98
BC-24
24
149
188
0.74
BC-31
25A
178
295
0.72
BC-27
26A
109
170
0.44
BD-16
27
350
445
0.70
BD-14
28
478
472
2.2
B0-18
30A
186
272
1.0
Data Qualifiers:
U ¦ Substance undetected at the method detection limit shown.
E ¦ quantity listed 1s an estimated value.
A-2
-------
TABLE A-2. CONCENTRATION OF LOW MOLECULAR WEIGHT
AROMATIC HYDROCARBONS IN DENNY WAY CSO OFFSHORE SEDIMENTS
(ug/kg DRY WEIGHT - ppb)
Naphth-
Acenaph-
Acenaph-
Phenan-
Anthra-
Survey
Station Sample
alene
thyl ene
thene
Fluorene
threne
cene
PTI and
Tetra Tech
1988
NS-01
NS-01
U36
El.7
E29
E15
E230
E50
Mai 1ns
1980
10041
10041
220
20
50
60
400
230
Romberg
et al.
1984
A060
A060
E17
E17
S0032
S0032
560
E51
430
5400
£2100
Romberg
et al.
1987
BC-33
2
U80
U180
U100
U100
U270
UlOO
BC-26
3
120
U180
U100
U100
580
210
BD-17
5
140
U180
UlOO
130
1050
360
BC-30
7
500
U180
120
C80
1900
580
BC-16
10
170
U180
140
130
1200
400
BD-10
12
no
U180
U100
UlOO
550
250
BC-32
14A
110
U180
U100
U100
400
UlOO
BC-23
15
U80
U180
U100
UlOO
450
240
BC-29
16
130
U160
120
1500
1220
240
BC-21
17
170
U180
200
UlOO
4400
1170
BC-17
18
140
U180
U100
300
2280
1170
BD-15
19
250
U180
170
640
3700
260
BO-12
20
150
U180
130
150
1470
250
B0-09
21
U80
U180
U100
160
800
210
BD-08
22
120
U180
120
260
1810
2260
CC-31
25A
U80
U180
140
UlOO
350
UlOO
BC-27
26A
U80
U180
U100
UlOO
240
UlOO
BO-16
27
1340
U180
12800
31500
98600
40700
BD-14
28
350
U180
410
900
6400
3510
BD-18
30A
U80
U180
U100
UlOO
550
200
Data Qualifiers:
U - Substance undetected at the method detection limit shown.
E ¦ Quantity listed Is an estimated value.
A-3
-------
TABLE A-3. CONCENTRATION OF HIGH MOLECULAR WEIGHT AROMATIC
HYDROCARBONS IN DENNY WAY CSO OFFSHORE SEDIMENTS
(ug/kg DRY WEIGHT = ppb)
Survey Station Sample
Fluor-
anthene
Pyrene
Dlbenzo- Total
Berizo(b)- Benzo(k)- Indeno- (a,h)- Benzo- Benzo-
Berizo(a)- fluor- fluor- Benzo(a)- (1,2,3-cd)- anthra- (g.h,i)- fluoran-
anthracene Chrysene anthene anthene pyrene pyrene cene perylene thenes
PTI and
Tetra Tech
1988 NS-01
Romberg
et al.
1984
Romberg
et al.
1987
NS-01
Mai ins et
al. 1980 10041 10041
A060
B060
S0032
AO 60
B060
S0032
E440
490
72
E610
10000
E370 U2.1 U2.4 E94
E140
U2.6 U2.8 U4.3 U2.5
640
53
E610
12000
310
5400
360
8900
Data Qual ifiers:
U » Substance undetected at the method detection limit shown.
E ¦ Quantity listed 1s an estimated value.
260
E610
1300
150
640
720
BC-33
2
250
2620
190
360
360
U500
U500
U500
480
BC-26
3
900
1000
610
1130
850
560
U500
720
1200
B0-17
5
1590
1600
1070
U130
Ul 30
610
U500
710
2400
BC-30
7
2170
2020
1730
2400
1700
U500
U500
740
2400
BC-16
10
1460
1830
1060
1400
1060
560
U500
U500
1680
BD-I0
12
880
890
1100
1200
850
610
U500
680
1500
BC-32
14A
300
260
250
510
340
U500
U500
U500
520
BC-23
15
430
370
370
590
780
U500
U500
U500
950
BC-29
16
1730
1450
1060
1190
950
790
U500
620
1530
BC-21
17
6800
5200
4000
5000
2400
1300
U500
1400
4500
BC-17
18
3230
2750
2180
2860
1760
800
U500
800
2700
BD-15
19
4800
4000
3200
4000
1740
700
U500
U500
3500
B0-12
20
1900
2000
1200
1530
820
U500
U500
U500
1980
BD-09
21
690
640
830
470
560
U500
U500
700
1120
BD-08
22
2500
1840
2720
3140
870
800
U500
U500
2370
BC-31
25A
460
440
290
480
280
U500
U500
U500
540
BC-27
26A
240
240
150
280
170
U500
U500
U500
350
BD-16
27
61500
36200
10700
26500
7500
U500
U500
U500
16400
BD-14
28
6730
5000
3140
4000
1900
U500
U500
U500
3300
BD-18
30A
660
630
390
680
490
U500
U500
930
A-4
-------
TABLE A-4. CONCENTRATION OF PHENOLS IN DENNY WAY CSO OFFSHORE SEDIMENTS
(ug/kg DRY WEIGHT - ppb)
2,4-
2-Methyl- 4-Methyl- Dimethyl -
Survey Station Sample Phenol phenol phenol phenol
PTI and
Tetra T©ch
1988 NS-01 NS-Q1 U6.0 U13 E37 U17
Romberg
et al.
BC-33
2
U80
BC-26
3
U80
BD-17
5
90
BC-30
7
U80
BC-1B
10
U80
BD-10
12
U80
BC-32
14A
100
BC-23
15
UBO
BC-29
16
580
BC-21
17
140
BC-17
18
U80
BD-15
19
190
BD-12
20
240
BO-09
21
130
BD-08
22
860
BC-31
25A
100
BC-27
26A
U80
BD-16
27
900
BO-14
28
1900
BD-18
30A
220
Data Qualifiers:
U • Substance undetected at the method detection limit shown.
E ¦ Quantity listed Is an estimated value.
A-5
-------
TABLE A-5. CONCENTRATION OF SUBSTITUTED PHENOLS IN
DENNY WAY CSO OFFSHORE SEDIMENTS
(ug/kg DRY WEIGHT = ppb)
2,4- 4-Chloro- 2,4,6- 2,4,5- Penta-
2-Chloro- Dlchloro- 3-methyl- Trichloro- Trichloro- chloro- 2-N1tro-
Survey Station Sample phenol phenol phenol phenol phenol phenol phenol
PTI and
Tetra Tech
1988 NS-01 NS-01 U12 U33 U16 U31 U35 U2200
Romberg
et al.
BC-33
2
U180
U120
BC-26
3
U180
U120
BO-17
5
790
380
BC-30
7
U180
BD-08
22
S60
Data qualifiers:
U » Substance undetected at the method detection limit shown.
A-6
-------
TABLE A-6. CONCENTRATION OF CHLORINATED AROMATIC HYDROCARBONS
IN DENNY WAY CSO OFFSHORE SEDIMENTS
(ug/kg DRY WEIGHT » ppb)
1.3- 1,4- 1.2- 1,2,4- 2-Chloro- Hexa-
Dlchloro- Dlchloro- Dlchloro- Trlchloro- naphtha- chloro-
Survey Station Sample benzene benzene benzene benzene lene benzene
PTI and
Tetra Tech
1988 NS-01 NS-01 U110 U110 U110 U180 U14 U93
Malins et
al. 1980 10041 10041 0.3
Data Qual 1f1ers:
U • Substance undetected at the method detection limit shown.
A-7
-------
TABLE A-7. CONCENTRATION OF CHLORINATED ALIPHATIC HYOROCARBONS
IN DENNY WAY CSO OFFSHORE SEDIMENTS
(ug/kg DRY WT = ppb)
Hexachl oro'
Survey Station Sample butadiene
PTI and
Tetra Tech
1988 NS-01 NS-01 U2200
Romberg
et al.
1984 S0032 S0032 5.1
Data Qualifiers:
U » Substance undetected at the method detection limit shown.
A-8
-------
TABLE A-8. CONCENTRATION OF PHTHALATES IN
DENNY WAY CSO OFFSHORE SEDIMENTS
(ug/kg DRY WEIGHT = ppb)
81s-
D1-n- Butyl (2-ethyl- D1-n-
Dlmethyl- butyl- benzyl hexyl)- octyl-
Survey Station Sample phthalate phthalate phthalate phthalate phthalate
PTI and
Tetra Tech
1988 NS-01
Romberg
et al.
1984
Romberg
et al.
1987
A060
8050
S0032
NS-01
A060
B060
S0032
E17
E17
U2.3
770
111. 4
520
23000
13000
BC-33
2
U80
U130
U130
1340
U130
BC-26
3
U80
1670
220
1090
250
B0-17
5
U80
1420
380
17300
1160
BC-30
7
U80
790
650
15600
U130
BC-16
10
U80
1000
500
400
U130
B0-10
12
U80
700
250
2240
450
BC-32
14A
U80
U130
U130
12100
U130
BC-23
15
U80
U130
710
8800
U130
BC-29
16
U80
400
410
22500
U130
BC-21
17
U80
940
870
37000
U130
BC-17
18
U80
1030
310
12400
U130
BD-15
19
100
1020
680
18200
U130
BD-12
20
U80
810
810
20800
U130
BD-09
21
U80
590
230
4300
U130
BD-08
22
U80
610
540
34100
U130
BC-31
25A
U80
910
160
53700
U130
BC-27
26A
U80
U130
U130
800
U130
BD-16
27
180
340
1100
1200
U130
BO-14
28
120
280
1830
400
U130
BD-18
30A
U80
U130
520
500
U130
Data qualifiers:
U » Substance undetected at the method detection limit shown,
E - Quantity listed Is an estimated value.
A-9
-------
TABLE A-9. CONCENTRATION OF MISCELLANEOUS OXYGENATED COMPOUNDS
IN DENNY WAY CSO OFFSHORE SEDIMENTS
(ug/kg DRY WEIGHT - ppb)
Benzyl Benzoic Dlbenzo- 2-Methyl-
Survey Station Sample Isophorone alcohol acid furan naphthalene
PTI and
Tetra Tech
1988 NS-01 NS-01 U22 U310 U110 E18 E7
Mai 1ns et
al. 1980 10041 10041 90
Data Qualifiers:
U - Substance undetected at the method detection 11m1t shown.
E - Quantity listed Is an estimated value.
A-10
-------
TABLE A-10. CONCENTRATION OF PESTICIDES AND PCBS IN OENNY WAY CSO OFFSHORE SEDIMENTS
(ug/kg ORY WEIGHT =» ppb)
Survey
Station Sample
4,4'-D0E 4,4'-DOD 4,4'-0DT
Aldrln
DleldHn
Alpha-
BHC
Beta-
BHC
Ganrna-
Delta- BHC
BHC (lindane)
PTI and
Tetra Tech
1988 NS-01 NS-01
U4.8 U5.9
U5.3
U4.4
U4.1
U2.7
U6.0
U3.3 U3.1
Romberg
et al.
1984
S0032 S0032
21 12
95
Endrln- Hepta- Total
Survey Station Sample Chlordane Endrln aldehyde chlor PCBs
PTI and
Tetra Tech
1988 NS-01
NS-01
Mai 1ns et
al. 1980
Romberg
et al.
1984
10041 10041
1406 1406
1512 1512
1603 1603
1606 1606
1612 1612
1706 1706
1810 1310
A060 A060
B060 B060
C060 C060
S0032 S0032
Romberg
et al.
1987
BC-33
BC-26
BD-17
BC-30
BC-16
BD-10
BC-32
BC-23
BC-29
BC-21
BC-17
BO-15
BD-12
BO-09
BO-08
BC-31
BC-27
BO-16
BD-14
BO-18
2
3
5
7
10
12
14A
15
16
17
18
19
20
21
22
25A
26A
27
28
30A
U72
U5.5
U7.2
U4.1
U390
158
1930
1712
2145
2624
1111
479
742
8.1
170
2.3
1448
260
410
510
770
580
670
160
170
290
300
490
30
120
30
1510
510
220
300
1060
930
Data Qualifiers:
U - Substance undetected at the method detection limit shown.
A-ll
-------
TABLE A-ll. CONVENTIONAL PARAMETERS IN DENNY WAY CSO OFFSHORE SEDIMENTS
Percent
Total
Survey Station Sample Rep Sol Ids
Percent
Percent Total Oil and
Volatile Organic Percent Grease Sulfide
Solids Carbon Nitrogen (ppm) (ppm)
PTI and
Tetra Tech
1988 NS-01
Romberg
et al.
1987 BC-09
BC-33
BC-26
BC-19
BD-17
BC-25
BC-30
BC-22
BC-18
BC-16
BD-13
BD-10
BC-28
BC-32
BC-23
BC-29
BC-29
BC-21
BC-17
BO-15
BD-15
BD-15
BO-12
BD-09
B0-08
BD-07
BC-24
BC-31
BC-27
BO-16
BD-14
BO-18
NS-01
1
2
3
4
5
6
7
8
9
10
11
12
13
14A
15
16
16
17
18
19
01
19
02
19
Mean
20
21
22
23
24
25A
26A
27
28
30A
83.03 2.18
56.17 3.99
51.95 5.23
52.35 5.72
55.42 5.53
49.43 6.60
48.33 7.78
48.88 8.33
56.04 5.18
49.14 7.22
50.40 6.83
57.94 5.47
49.88 6.08
27.81 13.1
40.15 8.27
62.77 5.13
57.52 7.52
57.52 7.52
59.27 9.63
54.83 8.81
50.83 9.48
48.36 11.2
49.59 10.3
51.02 7.41
48.91 9.35
54.53 7.38
49.95 7.13
54.86 5.90
43.39 7.91
59.57 4.57
70.86 3.84
41.02 14.5
38.61 8.63
E0.43 0.034
790 66
Data Qualifiers:
E » quantity listed Is an estimated value.
A-12
-------
APPENDIX B
DUVIAMISH RIVER SLIP 4 PROBLEM AREA
SEDIMENT CONTAMINANT DATA
-------
TABLE B-l. CONCENTRATIONS OF INORGANICS IN DUUAMISH RIVER SLIP 4 SEDIMENTS
(rag/kg DRY WEI6HT = ppm)
Survey
Station
Sample
Antimony
Arsenic
Cachiun
Chrnmi urn
CoDDer
Iron
Lead
PTI and
Tetra Tech 1988
DR-08
DR-08
33.2
16.1
4.15
E86
126
53200
257
EPA 1982. 1983
E19
E19(1982)
U0.1
15.0
3.3
E19
E31
19900
218
E19
E19(1983)
U0.1
16.0
2.3
53
150
44700
298
E19A
E19A
U0.1
12.0
1.1
28
92
36000
115
Sanple 1987b
SL-Ol
8431
—
E21
E4.3
E62
El 20
—
E890
SL-02
8432
--
E12
E0.29
E46
E290
—
E92
Hanaanese
Nickel
Seleniun
Silver
Zinc
Mercury
E569
36.8
0.39
El.58
E315
E0.605
137
15
—
2.0
251
0.4a
290
40
0.2
0.42
293
0.211?
262
23
0.1
0.12
187
0.12?
~
E45
—
—
E450
E0.094
—
E38
—
—
E130
E0.28
Data Qualifers:
U «= Substance undetected at the method detection limit.
E » Quantity listed is an estimated value.
a Value reported in ag/kg Met weight.
b Sanple. T., 23 October 1987. personal conaunication.
-------
TABLE B-2. CONCENTRATIONS OF EXTRACTABLE 0R6ANIC COMPOUNDS IN DUWAMISH RIVER SLIP 4 SEDIMENTS
(ug/kg DRY WEIGHT = ppb)
PHENOLS AND SUBSTITUTED PHENOLS
Survey Station Sarale
PTI and
Tetra Tech 1988
EPA 1982-1983
DR-08
E19
E19
E19A
DR-08
E19(1982)
E19(1983)
E19A
E19
E19
E19A
E19(1982)
E19(1983)
E19A
Survey
PTI and
Tetra Tech 1988
EPA 1982-1983
Station
DR-08
E19
E19
E19A
Sarole
DR-08
E19(1982)
E19(1983)
E19A
Phenol
E78
U200
U50
4-chloro-
3-methyl
Phenol
U9
LOW MOLECULAR WEI6HT AROMATIC HYDROCARBONS
Naph-
IMlSOS
El 70
U100
U100
2-methvl phenol
U5.0
2.4.6-tri
chloro-
Phenol
U15
Acenaph-
ltU£l£3£
E52
U100
U100
4-methvlphenol
E60
USO
U50
2,4,5-tri-
chloro-
phenol
U39
Acenaph-
thene
El 10
1000
U100
2.4-di methvlphenol
U4.6
U50
U50
Penta-
chloro-
phenol
U150
U50
U50
Fluorene
E150
U100
U100
2-chlorophenol
U4.2
Phenanthrene
E970
2300
1100
2.4-dichlorophenol
U16
Anthracene
E250
1000
990
HIGH MOLECULAR WEIGHT AROMATIC HYDROCARBONS
Survey Station
Sarnie Fluoranthene
PTI and
Tetra Tech 1988
EPA 1982-1983
Survey
PTI and
Tetra Tech 1988
EPA 1982-1983
DR-08
E19
E19
E19A
Station
DR-08
E19
E19
E19A
DR-08
E19(1982)
E19 (1983)
E19A
Saazls
DR-08
E19(1982)
E19(1983)
E19A
El 500
4300
2300
Indeno-
(1,2,3-cd)-
ovrene
El 100
U100
U100
Pvrene
El 100
3900
2200
Dibenzo-
(a.h)anthracene
E270
U100
U100
Benzo(a)
anthracene
E820
1200
900
Benzo-
(g.h.i)-
pervlene
E660
U100
U100
Chrvsene
E930
1900
1400
Total Benzo-
f1uoranthene
IE59
2200
1640
Benzo(b)-
fluoranthene
E48
1110
920
Benzo(a)-
pvrene
E760
900
Benzo(k)-
fl uoranthene
E550
1100
720
-------
TABLE B-2. (Continued)
CHLORINATED AROMATIC HYDROCARBONS
1,3-dichloro- 1.4-dichloro- 1.2-dichloro- 1,2,4-trichloro- 2-chloro- Hexachloro-
Survev Station Sample benzene benzene benzene benzene naphthalene benzene
PT1 and
Tetra Tech 1988 DR-08 DR-08 U100 U100 U67 U95 U7.3 Ufil
EPA 1982-1983 E19 E19 (1982)
E19 E19 (1983) U100 U100 U100 U100 - uiOO
E19A E19A UIOO U100 UIOO U100 - UIOO
PHTHALATES
00
1
u>
Total Pentachloro-
butadienes
fi of isomers)
U260
Dinethyl- Butyl benzyl - Dl-n-octyl- Bis(2-ethylhexyl)- Diethyl- Di-n-butyl
Survey Station Sarnie phthalate phthalate phthalate phthalate phthalate phthalatP
PTI and
Tetra Tech 1988 DR-08 DR-08 E50 E290 E120
EPA 1982-1983 E19 E19 (1982)
E19 El9 (1983) UIOO UIOO UIOO UIOO UIOO UIOO
E19A E19A UIOO UIOO UIOO 4000 UIOO UIOO
MISCELLANEOUS COMPOUNDS
Survey StrtlOT
PTI and
Tetra Tech 1988
EPA 1982-1983
DR-08
E19
E19
E19A
Isoohorone Benzvl alcohol
DR-08
E19(1982)
E19(1983)
E19A
U7.9
U300
UIOO
UIOO
Benzoic acid
U62
U50
Dibenzofuran
E120
UIOO
U50
UIOO
2-wethvlnaphtha!ene
E72
UIOO
UIOO
-------
TABLE B-2. (Continued)
PESTICIDES AND PCBs
Survey
Station
Sarnie
4.4'-DDE
M'-ppp
4.4'-DDT
Aldrin
Dieldrin
Alpha-BHC
PTI and
Tetra Tech 1988
DR-08
DR-08
52
38
U15
U13
U12
U7.9
EPA 1982-1983
E19
E19 (1982)
—
—
—
—
E19
E19 (1983)
U10
U100
U100
U10
U10
U10
E19A
E19A
U100
U100
U1000
U100
U10
U100
Beta-BHC
Delte-BHC
BHC(Lindane)
Chiordane
Endrin
Endrinaldehvde
U17
U9.5
U9.1
U210
U16
68
E19
E19 (1982)
—
—
—
—
E19
E19 (1983)
U10
U10
U10
U100
U10
E19A
E19A
U10
U10
U10
U100
U10
—
CD
I
Survey
PTI and
Tetra Tech 1988
EPA 1982-1983
Sample 1987s
Schlender 1985b
E19
E19
E19A
Station
E19 (1982)
E19 (1983)
E19A
U12
U10
U100
Sample Total PCBs
DR-08
DR-08
E5800
E19
E19(1982)
11600
E19
E19(1983)
15600
E19A
E19A
11600
SL-01
8431
6000
SL-02
8432
4000
102
E7250
105
E5200
109
E6700
Data Qualifiers:
U = Substance undetected at the method of detection limit shown.
E s Quantity listed is an estimated value.
I = Incomplete sun. Data for one or more component compounds are missing.
a Sanple, T., 23 October 1987, personal ccnmunication.
''Schlender, M., 16 April 1985. personal ccnaunication.
------- |