COMMENCEMENT BAY NEARSHORE/TIDEFLATS
SUPERFUND SITE, TACOMA, WASHINGTON
REMEDIAL INVESTIGATIONS
DECISIONMAKING FRAMEWORK FOR
MANAGEMENT OF DREDGED MATERIAL;
APPLICATION TO
COMMENCEMENT BAY, WASHINGTON
PREPARED FOR:
WASHINGTON STATE
DEPARTMENT OF ECOLOGY
JULY 1985
PREPARED BY:
US Army Corps
of Engineers
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NOTICE
Throughout the text, tentative decisions by local authorities for the
Commencement Bay area are presented. For the Commencement Bay area, the
Washington Department of Ecology (WDOE) Superfund Project Manager, other WDOE
staff, the Seattle District Corps of Engineers staff, EPA Region X staff, and
other local agencies represent involved local authorities.
The tentative decisions are given only for the purpose of presenting
concepts on possible methods of quantifying the issues involved for ease of
decisionmaking. No consensus has been reached by Commencement Bay area
authorities on either the approach or the numerical guidance given, and the
workability of the system has not been tested.
The intent of the sections involving local authority tentative decisions,
and of the document as a whole, is to provide a valuable first step in
arriving at a decisionmaking framework with the full knowledge of the need for
further refinement prior to actual implementation.
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EXECUTIVE SUMMARY
The State of Washington Department of Ecology (WDOE) has entered into a
cooperative agreement with the US Environmental Protection Agency (EPA) to act
as lead agency in the implementation of Phase I Remedial Investigations for the
Commencement Bay Nearshore/Tideflats Superfund Site, Washington. Superfund
remedial action may involve removing and handling contaminated sediments found
in the bay. In addition, ongoing and proposed navigation activities in Com-
mencement Bay require dredging and disposal of contaminated sediments located
in the nearshore areas. As a result, Superfund site investigations and plan-
ning of navigation projects require identification and evaluation of alterna-
tive methods for dredging and disposal of contaminated sediments.
By agreement with WDOE, the Seattle District, US Army Corps of Engineers,
has requested the Environmental Laboratory, US Army Engineer Waterways Experi-
ment Station (WES), to develop a decisionmaking framework for dredged material
management that is based on the results of technically sound test protocols.
The decisionmaking framework considers sediment chemistry, physicochemical
nature of disposal site environments, and biological effects of sediment con-
taminants and compares test results from sediments to be dredged with test
results from reference sediments and with established criteria. Test protocols
are discussed that consider the physicochemical conditions posed by aquatic
open-water and confined nearshore and upland disposal environments. Discrip-
tions of the physicochemical conditions at each disposal environment are pro-
vided as well as descriptions and citations of the test methods to be conducted.
In addition, examples of test results obtained from recent test applications
at other Corps dredging projects are discussed. Test results are used to
formulate management strategies regarding placement of dredged material in
specific physicochemical disposal environments and to determine what treatment
and control methods are warranted to dispose of one or more contaminated sedi-
ments in an environmentally acceptable manner.
The decisionmaking framework is illustrated by applying it to specific
sediments from Commencement Bay in the form of case studies at the end of
this rei/uit ;-'r.t.r th* L. •', s tic inilirl devr-lopment of. n clecj.sionmcil>'ing lror
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PREFACE
This report presents a decisionmaking framework based on a management
strategy for dredged material that incorporates results of a suite of test
protocols to assess the effects of physicochemical changes on contaminant
mobility from dredged material placed in aquatic, wetland, and upland disposal
environments.
This study was conducted^at the US Army Engineer Waterways Experiment
Station (WES) during the period October 1983 through January 1985 by Drs. C. R.
Lee, R. K. Peddicord, and M. R. Palermo, and Mr. N. R. Francinques under the
general supervision of Mr. D. L. Robey, Chief, Ecosystem Research and Simula-
tion Division; Mr. A. J. Green, (deceased), formerly Chief, Environmental
Engineering Division; and Dr. John Harrison, Chief, Environmental Laboratory.
Technical contributions in the form of examples of test protocol re-
sults and preparation of Appendix C tables were received from the following:
Dr. B. L. Folsom, Jr., for the plant uptake/bioassay tests; Dr. J. W. Simmers,
Dr. S. Kay, and Mr. R. G. Rhett for the earthworm bioassay test; Dr. J. M.
Brannon, and Mr. N. R. Francingues for the leachate tests; Dr. M. R. Palermo
for the effluent tests; Drs. T. M. Dillon and H. E. Tatem and Mr. V. A.
McFarland for the aquatic and benthic bioassay tests; and Mr. J. G. Skogerboe
for the surface runoff tests.
Review and constructive comments were received on 17 May 1984 from a
working group of that included Dr. R. Chaney, US Department of Agriculture—
Agriculture Research Service, Dr. J. Anderson, Battelle Northwest Laboratories;
Dr. W. Adams, Monsanto Co.; Mr. N. Rubenstein, US Environmental Protection
Agency (EPA), Dr. J. O'Connor, New York University; Dr. W. Peltier, EPA;
Dr. W. Pequegnat, Consulant, College Station, Texas; Dr. J. Rogers, North
Texas State University; Dr. J. Skelly, Pennsylvania State University; Mr. K.
Phillips, Seattle District, US Army Corps of Engineers; and Mr. J. Krull,
Washington Department of Ecology.
Additional comments were received on 6-10 August 1984 from members of the
WES Plant and Animal Working Groups that included the following: Dr. W. Berry,
University of California, Los Angeles; Dr. N. Beyer, US Fish and Wildlife Ser-
vice; Dr. F. Bingham, University of California, Riverside; Dr. G. Bryan, Marine
Biological Society, United Kingdom; Dr. R. Chaney, US Department of Agricul-
ture (USDA); Dr. B. Davies, University College of Wales, United Kingdom;
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Dr. C. Edwards, Rothamsted Experimental Station, United Kingdom; Dr. C. Foy»
USDA; Dr. Ad H. L. Huiskes, Delta Institute of Hydrobiological Research, The
Netherlands; Dr. M. Ireland, University College of Wales, United Kingdom;
Dr. M. Johnson, University of Liverpool, United Kingdom; Dr. R. H. D. Lambeck,
Delta Institute of Hydrobiological Research, The Netherlands; Dr. J. Marquenie,
Technology for Society, TNO, The Netherlands; Dr. E. Neuhauser, Cornell Univer-
sity; Dr. W. Patrick, Jr., Louisiana State University (LSU); Dr. P. Peterson,
University of London, United Kingdom; Dr. B. Pierce, Office, Chief of Engi-
neers; Dr. F. Prosi, University of Heidelberg, FRG; Dr. W. Stickle, LSU;
Dr. W. van Driel, Institute of Soil Fertility, The Netherlands; Dr. B. Walton,
Oak Ridge National Laboratory; Dr. G. Wilhelm, Morton Arboretum; Dr. N. Page,
Clemson University; Mr. B. Hunter, University of Essex, United Kingdom; Mr. J.
Mansky, New York District; Mr. J. Nieuwenhuize, Delta Institute for Hydrobio-
logical Research, The Netherlands; Mr. A. Palazzo, Cold Regions Research and
Engineering Laboratory, CE; Mr. N. Rubenstein, EPA; Ms. N. Houghton, University
College of Wales, United Kingdom; and Ms. A. Mudroch, National Water Research
Institute, Canada.
The Commanders and Directors of WES during the study and the preparation
of this report were COL Tilford C. Creel, CE, and COL Robert C. Lee, CE.
Technical Director was Mr. F. R. Brown.
This report should be cited as follows:
Lee, C. R., et al. 1985. "Decisionmaking Framework for Man-
agement of Dredged Material: Application to Commencement Bay,
Washington," Miscellaneous Paper D-85- , US Army Engineer
Waterways Experiment Station, Vicksburg, Miss.
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CONTENTS
EXECUTIVE SUMMARY 1
PREFACE 2
LIST OF FIGURES 8
LIST OF TABLES 8
CONVERSION FACTORS, NON-SI TO SI (METRIC) UNITS OF MEASUREMENT .... 13
PART I: INTRODUCTION 14
Background 14
Purpose and Scope ....... 16
PART II: EVALUATION AND MANAGEMENT OF DREDGED MATERIAL DISPOSAL ... 19
Management Strategy 19
Initial evaluation 19
Consideration of aquatic disposal 23
Aquatic disposal with restrictions . . 24
Consideration of upland disposal 24
Upland disposal with restrictions . 25
Description of Test Procedures 25
Aquatic disposal 25
Physicochemical conditions 25
Evaluation of aquatic impacts 26
Aquatic bioassay and bioaccumulation 26
Water column 28
Chemical evaluation 29
Biological evaluation 29
Mixing 29
Benthic 34
Upland disposal 36
Physicochemical conditions 35
Contaminant mobility determination 37
Effluent quality 37
Surface runoff quality 40
Leachate quality 41
Plant uptake 43
Animal uptake 45
Cost of conducting test protocols 46
Contaminant detection limits 47
Decisionmaking Framework 47
Responsibility for local authority decisions 48
Initial evaluation of contaminants . 49
Decision of no contamination 51
Decision of sediment contamination 51
Aquatic disposal with restrictions 53
Submerged discharge ......... 53
Subaqueous confinement 53
Capping 54
Chemical/physical/biological treatment 54
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Upland disposal with restrictions 55
Site selection and design 55
Available options 56
Design considerations ... 57
Restrictions 57
Effluent controls 58
Runoff controls 58
Leachate controls .... 58
Control of contaminant uptake 59
Controls of atmospheric contaminants 59
PART III: EXAMPLE APPLICATION OF FRAMEWORK AND INTERPRETATION OF
TEST RESULTS 60
Disposal Site Description 60
Aquatic environment 60
Upland environment 60
Nearshore environment 61
Sediment Description 64
Example Interpretation of Results 65
Approach 65
Discussion of possible Commencement Bay area local
authority decisions 65
Example Interpretation of Results—Sediment A 66
Aquatic disposal-sediment A 67
Water column evaluation 67
Chemical evaluations 67
Chemical evaluation of contaminants for which acute
water-quality criteria exist 67
Chemical evaluation of contaminants for which acute
water-quality criteria do not exist 69
Biological evaluation . . . 69
Mass loading assessment 69
Benthic evaluation 70
Chemistry and toxicity evaluations 70
Mass loading assessment 70
Overall conclusion 72
Upland disposal-sediment A 72
Effluent evaluation 72
Chemical evaluations 72
Chemical evaluation of contaminants for which acute
water-quality criteria exist 72
Mass loading assessment 72
Surface runoff evaluation 74
Chemical evaluations 74
Chemical evaluation of contaminants for which acute
water-quality criteria exist 74
Mass loading assessment 74
Leachate quality evaluation 76
Plant uptake evaluation 75
Animal uptake evaluation 76
Human exposure evaluations 77
Nearshore disposal—sediment A 77
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Example Interpretation of Results—Sediment B 78
Aquatic disposal-sediment A 78
Water column evaluation 78
Chemical evaluations 78
Biological evaluations 78
Benthic evaluation ..... 78
Chemical and toxicity evaluation 78
Bioaccumulation evaluation 79
Overall conclusion 79
Upland disposal-sediment B 79
Effluent evaluation . 79
Chemical evaluation 79
Biological evaluation 79
Surface runoff evaluation 80
Chemical evaluations 80
Chemical evaluation of contaminants for which acute
water-quality criteria exist 80
Chemical evaluation of contaminants for which acute
water-quality criteria do not exist 81
Leachate quality evaluation 82
Plant uptake evaluation 82
Animal uptake evaluation 83
Human exposure evaluation 83
Nearshore disposal-sediment B 83
Example Interpretation of Results—Sediment C 84
Aquatic disposal-sediment C 84
Water column evaluation 84
Chemical evaluation 84
Chemical evaluation of contaminants for which acute
water-quality criteria exist 84
Chemical evaluation of contaminants for which acute
water-quality criteria do not exist 84
Biological evaluation 84
Benthic evaluation 84
Chemistry and toxicity evaluation 84
Bioaccumulation evaluation 85
Overall conclusion 85
Upland disposal-sediment C 85
Effluent evaluation 85
Chemical evaluation 85
Chemical evaluation of contaminants for which acute
water-quality criteria exist 85
Chemical evaluation of contaminants for which acute
water-quality criteria do not exist 86
Biological evaluation 86
Surface runoff evaluation 87
Chemical evaluations 87
Chemical evaluation of contaminants for which acute
water-quality criteria exist 87
Chemical evaluation of contaminants for which acute
water-quality criteria do not exist 87'
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Page
Leachate quality evaluation 87
Plant uptake evaluations 87
Animal uptake evaluation 88
Human exposure evaluation 88
Nearshore disposal—sediment C &8
PART IV: SUMMARY 90
PART V: RECOMMENDATIONS 91
REFERENCES 94
TABLES 1-22
APPENDIX A: DECISIONMAKING FRAMEWORK FOR AQUATIC DISPOSAL Al
APPENDIX B: DECISIONMAKING PRAMEWORK FOR UPLAND DISPOSAL Bl
APPENDIX C: RELATED INFORMATION AND DATA TABLES Cl
APPENDIX D: MIXING ZONE PROCEDURES Dl
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LIST OF FIGURES
No. Pagf
1 Management strategy flowchart . 20
2 Modified elutriate test procedure 38
3 Effluent quality predictive technique 39
4 Flowchart for initial decisions for using framework 50
5 Nearshore disposal: filling of Milwaukee Waterway 63
6 Flowchart for Seattle decisionmaking for aquatic disposal .... 68
7 Flowchart for decisionmaking for aquatic disposal benthic
impacts with a mass loading assessment 71
8 Flowchart for decisionmaking for unfiltered effluent water
quality with mass loading assessment 73
9 Flowchart for decisionmaking for unfiltered surface runoff
water quality with mass loading assessment 75
LIST OF TABLES
No.
1 Relative Time and Cost Estimates for Conducting Test Protocols
2 Detection Limits for a Preliminary List of Contaminants of Potential
Concern in Commencement Bay
3 Hypothetical Example of Concentrations of Dissolved Contaminants in
Standard Elutriates of Three Puget Sound Sediments
4 Hypothetical Example of Toxicity of Elutriates of Three Puget Sound
Sediments
5 Hypothetical Example of Toxicity of Elutriates of Three Puget Sound
Sediments to Oyster Larvae (Crassostrea gigas)
6 Hypothetical Example of Toxicity of Deposits of Four Puget Sound
Sediments to Amphipods Grandifoxus grandis
1 Hypothetical Example of Toxicity of Deposits of Four Puget Sound
Sediments to Four Benthic or Epibenthic Species
8 Hypothetical Example of Contaminant Concentrations in Tissues of
the Clam Maaoma balthica Exposed to Deposits of Four Puget Sound
Sediments for 30 Days
9 Hypothetical Example of Contaminant Concentrations in Tissues of the
Shrimp Pandalus borealis Exposed to Deposits of Four Puget Sound
Sediments for 30 Days
10 Hypothetical Example of Contaminant Concentrations in Tissues of the
Polychaete Worm Neanthes arenaoeodentata Exposed to Deposits of Four
Puget Sound Sediments for 30 Days
11 Hypothetical Example of Contaminant Concentrations in Tissues of the
Juvenile English Sole Parophrys vetulus Exposed to Deposits of Four
Puget Sound Sediments for 30 Days
12 Hypothetical Example of Concentrations of Dissolved Contaminants in
Effluents of Confined Disposal Areas Containing Three Puget Sound
Sediments
13 Hypothetical Example of Concentrations of Dissolved Contaminants in
Surface Water Runoff of Confined Disposal Areas Containing Three
Puget Sound Sediments
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No.
14 Hypothetical Example of Total or Bulk Contaminant Concentration in
Four Puget Sound Sediments
15 Hypothetical Example of Concentrations of Dissolved Contaminants in
Leachate of Confined Disposal Areas Containing Three Puget Sound
Sediments
16 Hypothetical Example of DTPA-Extractable Metals from Four Puget Sound
Sediments
17 Hypothetical Example of Plant Growth, Tissue Content, and Total Uptake
of Contaminants for Yellow Nutsedge, Cyperus esoulentus, Grown in
Four Puget Sound Sediments
18 Hypothetical Example of Toxicity of Four Puget Sound Sediments to
Earthworms, Eisenia foetida
19 Hypothetical Example of Animal Growth, Tissue Content, and Total Uptake
of Contaminants for the Earthworm Eisenia foetida Exposed to Four
Puget Sound Sediments for 30 Days
20 Hypothetical Example of Concentrations of Dissolved Contaminants in the
Saturated Zone Leachate of a Nearshore Disposal Area Containing Three
Puget Sound Sediments
21 Hypothetical Example of Toxicity of Effluents (Modified Elutriates) of
Three Puget Sound Sediments
22 Summary of Tentative Seattle Local Authority Decisions Made for Three
Sediments and Three Potential Disposal Sites Using Hypothetical Test
Results
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(Pages 10-12 intentionally left blank)
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CONVERSION FACTORS, NON-SI TO SI (METRIC)
UNITS OF MEASUREMENT
Non-Si units of measurement used in this report can be converted to SI (metric)
units as follows:
Multiply
acres
cubic feet
cubic feet per second
cubic yards
feet
feet per second
miles (US statute)
pounds (mass)
square yards
By
4046.873
0.02831685
0.02831685
0.7645549
0.3048
0.3048
1.609347
0.4535924
0.8361274
To Obtain
square metres
cubic metres
cubic metres per second
cubic metres
metres
metres per second
kilometres
kilograms
square metres
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DECISIONMAKING FRAMEWORK FOR MANAGEMENT OF DREDGED MATERIAL;
APPLICATION TO COMMENCEMENT BAY, WASHINGTON
PART I: INTRODUCTION
Background
1. Navigable waterways of the United States have played a vital role in
the Nation's economic growth through the years. The US Army Corps of Engi-
neers (CE), in fulfilling its mission to maintain, improve, and extend these
waterways, is responsible for the dredging and disposal of large volumes of
sediment each year. Dredging is a process by which sediments are removed from
the bottom of streams, rivers, lakes, and coastal waters; transported via
ship, barge, or pipeline; and discharged to land or water. Annual quantities
of dredged material average about 290 million cu m in maintenance dredging
operations and about 78 million cu m in new work dredging operations with the
total annual cost now exceeding $250 million.
2. Over 90 percent of the total volume of material dredged is consid-
ered acceptable for disposal at a wide range of disposal alternatives. How-
ever, the presence of contamination in some locations has generated concern
that dredged material disposal may adversely affect water quality and aquatic
or terrestrial organisms. Since many of the waterways are located in indus-
trial and urban areas, some sediments may be highly contaminited with wastes
from these sources. In addition, sediments may be contaminated with chemicals
from agricultural practices.
3. The chemistry of contaminants in sediments, and thus their mobility
and potential to adversely impact the environment, is controlled primarily by
the physicochemical conditions under which the sediment exists. Fine-grained
sediments that are saturated with water typically are anoxic, reduced, and
near neutral in pH. These conditions exist in typical open-water aquatic
dredged material disposal sites, and may exist in other disposal options
such as marsh creation and disposal in shallow water along shorelines. In
this document the term "aquatic disposal" is used in a general sense to re-
fer to all disposal conditions in which fine-grained material remains water
saturated, anoxic, reduced, and near neutral in pH. In contrast, when a
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fine-grained sediment is taken out of the water and allowed to dry, it becomes
oxic and the pH may drop considerably. In this document all disposal options
in which a fine-grained sediment has these characteristics are referred to
generally as "upland disposal," even though such conditions can occur on the
surface of dredged material islands, the above-tide portions of fills, etc.
Nearshore confined disposal sites could have a combination of anoxic, reduced
conditions below tide elevation and oxic conditions in the dredged material
placed above tidal elevation.
4. Potential concerns associated with aquatic disposal include contam-
inants released into the water during and following disposal and the subsequent
toxicity and/or bioaccumulation of contaminants by aquatic organisms. Conse-
quences of bioaccumulation may include a wide range of effects from organism
toxicity to sublethal genetic abnormalities, food-web biomagnification, and
possibly eventual consumption by man. Potential concerns associated with
upland disposal include water-quality impacts from effluent discharged during
disposal, surface runoff and leachate following disposal, and uptake of con-
taminants by plants and animals inhabiting the area following disposal opera-
tions, with contaminants possibly reaching man by direct or indirect routes.
Each of these potential problems can be minimized by one or more management
practices.
5. Since the nature and magnitude of contamination in dredged material
may vary greatly on a project-to-project basis, the appropriate method of dis-
posal may involve any of several available disposal alternatives. Further,
control measures to manage specific problems associated with the presence or
mobility of contaminants may be required as a part of any given disposal al-
ternative. An overall management strategy for disposal of dredged material
is therefore required. Such a strategy must provide a framework for decision-
making to select the environmentally preferable disposal alternative and to
identify potentially appropriate control measures to minimize problems associ-
ated with the presence of contaminants. The decisionmaking framework should
also identify and document those sediments that require no special management
considerations.
6. The lead responsibility for the development of specific ecological
criteria and guideline procedures regulating the discharge of dredged and fill
material at the National level was legislatively assigned to the US Environ-
mental Protection Agency (EPA) in consultation or conjunction with the CE.
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The enactment of Public Laws 92-532 (the Marine Protection, Research, and
Sanctuaries Act of 1972) and 92-500 (the Federal Water Pollution Control Act
Amendments of 1972), concerned with the discharge of dredged and fill material,
required the CE to participate in developing guidelines and criteria for regu-
lating dredged and fill material disposal. The focal point of research for
these procedures is the CE Dredged Material Research Program (DMRP), which was
completed in 1978; the ongoing CE Dredging Operations Technical Support (DOTS)
Program and the Long-term Effects of Dredging Operations (LEDO) Program; and
the ongoing CE/EPA Field Verification Program (FVP). These research programs
have provided much of the technical bases for this document.
7. One site in which there is a need to assess the potential environ-
mental impacts of contaminants in sediments is in Commencement Bay in southern
Puget Sound near the city of Tacoma, Washington. The State of Washington De-
partment of Ecology (WDOE) has entered into a cooperative agreement with the
EPA to act as lead agency in the implementation of Phase I Remedial Investiga-
tions for the Commencement Bay Nearshore/Tideflats Superfund Site, Washington.
Superfund remedial action may involve removal and handling of contaminated
sediments found in the bay. In addition, ongoing and proposed navigation
activities in Commencement Bay require dredging and disposal of sediments
located in the nearshore areas. As a result, Superfund site investigations
and planning of navigation projects require identification and evaluation of
alternative methods for dredging and disposal,of contaminated sediments.
8. Several studies of the nearshore waters of Commencement Bay have
indicated sediment contamination by potentially toxic materials, accumulation
of some of those contaminants by estuarine biota, and even possible pollution-
related abnormalities in indigenous biota (Tetra Tech 1984). Considerable ef-
fort is currently under way to determine the extent of the contamination and
the potential threat to public health under the Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA). This effort is necessary
to determine what remedial actions are required to clean up and protect the
estuarine environment of Commencement Bay.
Purpose and Scope
9. By agreement with WDOE, the Seattle District, CE, has funded the
Environmental Laboratory, US Army Engineer Waterways Experiment Station (WES),
to develop a decisionmaking framework for environmental assessment of dredged
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material based on technically appropriate tests and scientifically sound inter-
pretation of test results. Its major focus is on the question of how should
dredged material be tested and the results interpreted to evaluate the degree
of potential contaminant impact and the disposal conditions in which the
dredged material would have minimal adverse impact on the overall environment.
Parts I and II of this document outline the appropriate types of tests and the
environmental interpretation of the results. These parts are written so as to
be generally applicable to all dredged material evaluations. Part III is an
example application of the guidance of Parts I and II to specific Commencement
Bay sediments and illustrates the integration of various test results and the
role of local regulatory goals and objectives in decisionmaking on the basis
of test results. This report describes a framework that provides a means of
obtaining a sound technical basis for decisionmaking regarding the disposal of
contaminated dredged material. The framework indicates which type of disposal
should be considered for a given dredged material and when restrictions on
disposal are warranted. Appendices A and B present details of the decision-
making framework for aquatic and upland disposal options, respectively, and
Appendix C contains related information and data tables. Appendix D gives
procedures for and examples of mixing-zone calculations.
10. The report describes testing protocols as they are related to the
physicochemical conditions posed by aquatic and upland disposal, and in the
example of Commencement Bay in Part III, to conditions in a "nearshore" site
which will result in some of the material retaining characteristics of aquatic
disposal and some of it becoming similar to typical upland conditions. Under
each of these alternatives, a discussion is presented of what each test is
intended to accomplish and why the information is important. The tests dis-
cussed have been proposed in a recent report (Francingues et al. 1985). The
present report discusses test procedures and the rationale for when a test
should be applied and the interpretation of test results. A decisionmaking
framework incorporating the interpretation of test results is discussed and
applied to specific sediments from Commencement Bay in case studies.
11. The framework indicates when disposal site controls and treatment
options are required and the availability of technology to achieve the re-
quired control or treatment. The framework is fully comprehensive as to
the present state of the art in technical knowledge, but does not address
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economics/cost feasibility of the recommended criteria or public acceptance/
sociopolitical factors. In addition, testing required to address design of
a disposal site or selection of necessary control or treatment options is
beyond the scope of this report.
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PART II: EVALUATION AND MANAGEMENT OF DREDGED MATERIAL DISPOSAL
12. The following discussion presents the general approach to the man-
agement of dredged material disposal in reference to a recent document on the
subject (Francingues et al. 1985). The discussion becomes more detailed in
describing the suite of tests used in the management strategy. The final por-
tion of this part discusses a general decisionmaking framework that incorpo-
rates test results and gives guidance on the interpretation of test results
for making decisions. The actual application of the framework to specific
sediments of Commencement Bay is discussed in Part III of this report.
Management Strategy
13. The following discussion is cited directly from Francingues et al.
(1985) and serves as a focus point for this report. The selection of a dis-
posal management strategy must consider the nature of the sediment to be
dredged, potential environmental impacts of the disposal of the dredged mate-
rial, nature and degree of contamination, dredging equipment, project size,
site-specific conditions, technical feasibility, economics, and other socio-
economic factors. This discussion presents an approach to consider the na-
ture and degree of contamination, potential environmental impacts, and related
technical factors. The approach, shown in the flowchart in Figure 1, consists
of the following:
a_. Initial evaluation to assess contamination potential.
b^. Selecting a potential disposal alternative.
£. Identifying potential problems associated with that alternative.
cl. Testing to evaluate the problems.
e_. Assessing need for disposal restrictions.
f_. Selecting an implementation strategy.
j». Identifying available control options.
_h. Examining design considerations to evaluate technical and eco-
nomic feasibility.
JL. Choosing appropriate control measures and technologies.
Initial evaluation
14. The initial screening for contamination is the initial evaluation
outlined in the proposed testing requirements for Section 404 of the Clean
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L I POTENTJAL I
IfS \ PROBLEM [
1 IMPLEMENTATION I
I STRATEGY |
DESIGN I AVAILABLE CONTROL I
CONSIDERATIONS | MEASURES |
ho
o
Figure 1. Management strategy flowchart
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Water Act (EPA 1980). The evaluation is designed to determine if there is
reason to believe the sediment contains any contaminants "in forms and amounts
that are likely to degrade the aquatic environment, including potential avail-
ability to organisms in toxic amounts." This evaluation also allows identi-
fication of specific contaminants of concern in the particular sediment in
question, so that testing and analyses may be focused on the most pertinent
contaminants. The initial evaluation section is quoted as follows from EPA
(1980), Section 230.61, page 85362:
§230.61 Initial evaluation of dredged or filled material.
(a) An initial evaluation shall be conducted and
documented to determine if there is reason to believe that
any dredged or fill material to be discharged into waters
of the United States contains any contaminant above back-
ground level. This initial evaluation will be used in as-
signing the proposed discharge to a category for testing.
This evaluation should be accomplished with existing data
on file with or readily available to the permitting au-
thority; Regional Administrator, EPA; and other public and
private sources, as appropriate. Factors which may be
considered for the extraction site and, if appropriate,
the disposal site, include, but are not limited to, the
following:
(1) Potential routes of introduction of specific
contaminants. These may be identified by examining maps,
aerial photographs, and other graphic materials that show
watercourses, surface relief, proximity to tidal movement,
private and public roads, location of buildings, agricul-
tural land, municipal and industrial sewage and storm
outfalls, etc., or by making field inspections.
(2) Previous tests on the material at the extrac-
tion site or on samples from other similar projects in the
vicinity, when there are similarities of sources and types
of contaminants, water circulation and stratification,
accumulation of sediments, general sediment characteris-
tics, and potential impact on the aquatic environment, as
long as no known changes have occurred to render the com-
parisons inappropriate.
(3) The probability of past substantial introduc-
tion of contaminants from land runoff (e.g., pesticides).
(4) Spills of toxic substances or substances desig-
nated as hazardous under Section 311 of the Clean Water
Act (see 40 CFR Part 116).
(5) Substantial introduction of pollutants from
industries.
(6) Source and previous use of materials proposed
for discharge as fill.
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(7) Substantial natural deposits of minerals and
other natural substances.
(b) Before the permitting authority concludes that
there is no reason to believe that contaminants are pres-
ent in the discharge material above background levels, he
should consider all relevant, reasonably available infor-
mation which might indicate its presence. However, if
there is no information indicating the likelihood of such
contamination, the permitting authority may conclude that
contaminants are not present above background levels. Ex-
amples of documents and records in which data on contami-
nants may be obtained are:
(1) Report of Pollution Caused Fish Kills (U.S.
EPA)
(2) Selected Chemical Spill Listing (U.S. EPA)
(3) Pollution Incident Reporting System (U.S. CG)
(4) Surface Impoundment Assessment (U.S. EPA)
(5) Identification of In-Place Pollutants and
Priorities for Removal (U.S. EPA)
(6) Revised Status Report-Hazardous Waste Sites
(U.S. EPA)
(7) Hazardous Waste Management Facilities in the
United States—1977 (U.S. EPA)
(8) Corps of Engineers studies of sediment
pollution
(9) Sediment tests for previously permitted
activities (U.S. CE/District Engineers)
(10) Pesticide Spill Reporting System (U.S. EPA)
(11) STORE! (U.S. EPA)
(12) Past 404(b)(l) evaluations
(13) USGS water and sediment data on major
tributaries
(14) Pertinent and applicable research reports
(15) NPDES permit records
Contaminant concentrations in the sediment to be dredged can be compared to
those concentrations of a reference and/or background sediment to assist in
evaluating a sufficient cause for concern. The determination of a critical
level of contamination above the reference and/or background should be made on
a site-by-site basis and will depend on the administrative goal established
for the site such as maintaining nondegradation, achieving cleaner conditions,
or returning to background conditions. Under some circumstances contamination
22
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factors of 1.5 above reference have been proposed as an acceptable approach.
The acceptability of elevation factors must be established through delibera-
tions with appropriate concerned parties and will be a local authority
decision.
15. If there is available information indicating contaminants are not
present above background levels, restrictions are not required. In this case
any disposal alternative may be selected, though the possibility of other
environmental impacts such as effects of salinity, substrate alternation,
and low dissolved oxygen concentrations must be considered in the final selec-
tion. Three disposal alternatives are shown in the flowchart (Figure 1) for
uncontaminated.or so-called "clean" sediments: [1]* aquatic, [2] upland, and
[3] others, which include marsh or wetland development and other beneficial
uses. The final selection is based on environmental considerations, available
dredging alternatives, site-specific conditions, technical feasibility,
economics, and other socioeconomic considerations.
16. If there is reason to believe that contaminants are present, the
sediment must be evaluated in relation to the conditions that would be present
at the disposal site to examine the potential for environmental impacts.
Either aquatic [4] or upland disposal [5] could be initially considered and
appropriately evaluated or both alternatives could be evaluated concurrently.
The selection of the disposal alternative to be considered is dependent on
the potential problems posed by contaminants, available dredging equipment,
site-specific conditions, technical feasibility, economics, and socioeconomic
considerations. The evaluation of aquatic or upland disposal of contaminated
sediment may not necessarily require that additional tests be conducted. As
EPA (1980) Section 230.60 points out, "Where the results of prior evaluations,
chemical and biological tests, scientific research, and experience can provide
information helpful in making a determination, these should be used. Such
prior results may make new testing unnecessary."
Consideration of
aquatic disposal [4]
17. Consideration of aquatic disposal [4] for a contaminated sediment
requires an evaluation of the potential impacts on the water column and the
* Numbers in brackets refer to the respective disposal alternative as num-
bered in Figure 1.
23
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benthic environment. Other special disposal problems such as effects on
health of disposal personnel would be a rare occurrence but should also be
considered. Water column impacts can be evaluated by chemical analysis of
dissolved contaminants for which water-quality criteria exist. Bioassays are
used when no water-quality criteria exist or when there is concern about pos-
sible interactive effects of multiple contaminants. The effects of mixing and
dilution should be considered during assessment of the test results.
18. Potential benthic impacts of deposited sediment are first evaluated
by comparing both contaminant concentrations and toxicity of the sediments in
the dredging and disposal sites. If contaminant concentrations and toxicity
in the dredging site sediment are lower than or similar to the concentrations
in the disposal site sediment, it can be concluded that disposal will not have
further unacceptable adverse impacts on the benthic environment. If contami-
nant concentrations or toxicity are greater in the dredging site sediment, a
bioaccumulation test should be performed. If the initial evaluation for con-
taminants and initial sediment characterization indicates a potential for
special dredging problems (e.g., noxious emissions), appropriate tests must be
performed.
19. If the impacts are acceptable, the dredged material can be disposed
in aquatic sites without restrictions [1]. If unacceptable, options for
aquatic disposal with restrictions [6] must be evaluated.
Aquatic disposal
with restrictions [6]
20. Four options are available for implementing aquatic disposal with
restrictions [6]. These options include bottom discharge; treating the mate-
rial by physical, chemical, or biological methods; confining the dredged mate-
rial subaqueously; and capping the dredged material subaqueously. Each option
may be used separately or in combination with other options. The design con-
siderations for these options must be examined to evaluate the technical feas-
ibility of the disposal alternative based on effectiveness, availability, com-
patibility ; cost, and scheduling. If the design is feasible, the appropriate
aquatic control measures and technologies can be chosen and implemented. If
the design is not feasible, upland disposal [5] should then be considered.
Consideration of
upland disposal [5]
21. Consideration of upland disposal [5] for a contaminated sediment
requires evaluation of the following potential problems: effluent quality,
24
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surface runoff quality, leachate production and quality, and contaminant up-
take by plants and animals. Impacts of effluent, runoff, and leachate quality
can be evaluated by chemical analysis of contaminants released in modified
elutriate, runoff, and leachate tests, respectively. If the contaminant levels
exceed applicable criteria after considering mixing and dilution effects, bio-
assays are performed to determine the potential toxicity. Plant and animal
uptake can be evaluated by appropriate bioassay and bioaccumulation tests. If
the initial evaluation and sediment characterization indicates a potential for
special dredging or disposal problems (e.g., noxious emissions), appropriate
tests must be performed. If the impacts are acceptable, the dredged material
can be disposed in upland areas without restrictions [2]. If unacceptable,
options for upland disposal with restrictions [7] must be evaluated.
Upland disposal
with restrictions [7]
22. Four basic options are available for implementing upland disposal
with restrictions. These options include containment, physical/chemical/
biological treatment, reuse, and storage and rehandling. Combinations of the
options exist for this strategy. The selection of the appropriate option is
dependent mainly on the nature and level of contamination, site-specific con-
ditions, economics, and socioeconomic considerations. The design considera-
tions for these options must be examined to evaluate the technical feasibility
of the disposal alternative based on effectiveness, availability, compatibil-
ity, cost, and scheduling. If the design is feasible, the appropriate upland
disposal control measures and technologies can be chosen and implemented. If
the design is not feasible, aquatic disposal [4] should be considered.
Description of Test Procedures
Aquatic disposal
Physicochemical conditions
23. When sediments are dredged from a waterway and placed in stable de-
posits in a low energy aquatic environment, very little change occurs in the
physicochemical nature of the dredged material. In other words, when a re-
duced anaerobic sediment with a pH value near neutral is disturbed, removed,
and placed in a similar aquatic environment, it will remain anaerobic with a
pH near neutral. Consequently; contaminant mobility at the aquatic disposal
25
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site will be very similar to that occurring at the original dredging site in
the waterway. There will be a minor tendency for limited oxidation to occur
as the dredged material is mixed with oxygenated water during the dredging
operation. However, the oxygen demand of the reduced sediment is usually so
great that any oxygen added via the dredging water will be consumed immedi-
ately and will not have any important effect on the physicochemical nature
of the sediment. The sediment will therefore remain reduced and maintain a
near-neutral pH similar to that originally found at the dredging site.
Evaluation of aquatic impacts
24. When highly contaminated dredged material is placed in an aquatic
environment, there is a conceptual potential for impacts due to release of
contaminants into the water column during disposal, although this potential
has rarely been realized in practice. In addition, there is potential for
physical effects on benthic organisms and for long-term toxicity and/or bio-
accumulation of contaminants from the dredged material. These biological
effects are best determined at present by site-specific bioassays. Other
special disposal concerns such as potential impacts on health of operating
crews would be a rare occurrence and beyond the scope of this document, but
should be evaulated when considered appropriate.
Aquatic bioassay and bioaccumulation
25. It must be recognized that aquatic bioassays of dredged material
cannot be considered precise predictors of environmental effects in the field.
They must be regarded as providing qualitative estimations of those effects,
making interpretation of the potential for environmentally adverse effects in
the field somewhat subjective. This interpretative uncertainty increases when
a parameter whose ecological meaning is uncertain is used as the bioassay end
point. In view of the interpretative difficulties, most of the animal bioas-
says in this document specify death, or occasionally the ecologically impor-
tant parameters of development or reproduction, as the response to be mea-
sured. The term "toxicity" is defined in APHA (1980) as "adverse effect to
a test organism caused by pollutants" and is used in this document in a more
restricted sense to refer to ecologically important bioassay end points such
as those directly related to survival, development, and reproduction.
26. The environmental interpretation of bioaccumulation data is even
26
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more difficult than for bioassays because in many cases it is impossible to
quantify either the ecological consequences of a given tissue concentration
of a constituent that is bioaccumulated or even the consequences of that body
burden to the animal whose tissues contain it. Almost without exception there
is little technical basis for establishing, for example, the tissue concentra-
tion of zinc in an organism that would be detrimental to that individual, not
to mention the uncertainty of estimating the effect of that organism's body
burden on a predator. Research is under way at WES, the EPA Environmental
Research Laboratory at Narragansett, and other laboratories in the United
States and abroad to determine the relationship, if any, between body burden
of contaminants and important biological functions. Dillon (1984) provides
an initial step in this process, but the database is still inadequate to allow
evaluation of the potential ecological consequences of a particular body bur-
den of a specific contaminant(s). Therefore, at present, bioaccumulation data
can be interpreted only by comparison to levels in organisms exposed to ref-
erence sediment, and to levels determined to be safe for human consumption.
Such levels have been established by the US Food and Drug Administration (FDA)
and Australian National Health and Medical Research Council for some contami-
nants in seafood and are presented in Appendix C, Table Cl, There are no such
levels for aquatic organisms not commonly eaten in these countries. However,
there is a potential for contaminants in nonfood organisms to reach some sea-
food organisms through predation. Although trophic transfer of contaminants
from aquatic prey to aquatic predator is known to occur, food-web biomagnifi-
cation of contaminants to higher concentrations in the predator than in the
prey has been established in aquatic systems for only a few contaminants, in-
cluding polychlorinated biphenyls (PCB). DDT, and mercury (and possibly
selenium, zinc, kepone, mirex, benzo(a)pyrene, and naphthalenes) (Biddinger
and Gloss 1984, Kay 1984). The above considerations lead to the recommenda-
tion that levels in predatory organisms considered safe for human consumption
should be applied to aquatic species that are seldom directly consumed by man
in order to protect against possible human impacts. The interpretative
guidance assumes that any statistically significant bioaccumulation relative
to animals not in dredged material, but living in reference material of similar
sedimentological character, is potentially undesirable. The evaluation of
experimental results using this approach requires the user to recognize the
27
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fact that a statistically significant difference cannot be presumed to predict
the occurrence of an important impact in the field.
27. Interpretive guidance for environmental tests .of dredged material
was the subject of a working group convened by the WES on 15-17 May 1984. The
participants were all recognized scientific experts in a wide variety of rele-
vant disciplines who also have experience in the practical application of en-
vironmental science to regulatory decisionmaking. They included Dr. R. Chaney,
US Department of Agriculture—Agriculture Research Service; Dr. J. Anderson,
Battelle Northwest Laboratories; Dr. W. Adams, Monsanto Co.; Mr. N. Rubenstein,
EPA; Dr. J. O'Connor, New York University; Dr. W. Peltier, EPA; Dr. W.
Pequegnat, Consultant, College Station, Texas; Dr. J. Rogers, North Texas
State University; Dr. J. Skelly, Pennsylvania State University; Mr. K.
Phillips, CE, Seattle Districtjand Mr. J. Krull, WDOE. After 3 days of dis-
cussion, concensus was reached on the following two major points related to
regulatory interpretation of properly conducted aquatic bioassay and bioaccumu-
lation testing of dredged material:
SL. There is a cause for concern about unacceptable adverse toxic-
ity impacts in the field when laboratory tests result in greater
than 50 percent toxicity attributable to the dredged material.
_b_. Bioaccumulation data can be interpreted in relation to human
health, but evaluation of ecological impacts of bioaccumulation
is much less certain at present. Tentative assessment of the
potential for such impacts must consider concentrations in tis-
sues of reference animals, and other effects of the sediment,
such as degree of toxicity.
Water column
28. The standard elutriate (EPA/CE 1977) is appropriate for evaluating
the potential for dredged material disposal to impact the water column. Since
this test includes contaminants in both the interstitial water and the loosely
bound (easily exchangeable) fraction in the sediment, it approximates the
fraction of chemical constituents that is potentially available for release
to the water column when sediments are dredged and disposed through the water
column. The standard elutriate is prepared by mixing the sediment and dredg-
ing site water in a volumetric sediment-to-water ratio of 1:4. Mixed with
agitation and vigorous aeration for 30 min, it is then allowed to settle for
1 hr. The supernatant is then centrifuged and/or filtered to remove particu-
lates prior to chemical analysis. This procedure is followed because the
28
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water-quality criteria apply only to dissolved contaminants and chemical anal-
yses of an unfiltered water sample cannot identify the bioavailable fraction
of sediment-sorbed contaminants. A detailed description of the procedure,
including sample preparation, is provided in EPA/CE (1977).
29. Chemical evaluation. Water-column impacts of dredged material may
be evaluated either in this paragraph or as specified in paragraph 30, depend-
ing on the situation. Where paragraph 14 identifies concern about the presence
of specific contaminants that may be released in soluble form, the standard
elutriate may be analyzed chemically and the results evaluated by comparison
to water-quality criteria for those contaminants after allowance for mixing
(paragraphs 31-36) at the disposal site. This provides an indirect evaluation
of potential biological impacts of the dissolved contaminants since the water-
quality criteria were derived from bioassays of solutions of the various con-
taminants. Chemical analyses of the standard elutriate are quantitatively in-
terpretable in terms of potential impact only for those contaminants for which
specific water quality criteria have been established.
30. Biological evaluation. If the water-quality criteria approach is
not taken, the potential for water-column impacts must be evaluated by bio-
assays, with consideration given to mixing (paragraphs 31-36). An aquatic
bioassay should also be used to determine the potential interactions among
multiple contaminants. In this way elutriate bioassays can aid in evaluating
the importance of dissolved chemical constituents released from the sediment
during disposal operations. The standard elutriate is prepared just as for
chemical use, but the filtrate is used as a bioassay test solution rather than
for chemical analysis. A series of experimental treatments and controls are
established using graded dilutions of the elutriate. The test organisms are
added to the test chambers and exposed under standard conditions for a pre-
scribed period of time. The surviving organisms are examined at appropriate
intervals to determine if the test solution is producing an effect. Any bio-
assay protocol designed for use with solutions can be used by substituting
the standard elutriate for the original solution. A useful general protocol
is presented in EPA/CE (1977).
31. Mixing. All data from chemical analyses and bioassays of the stan-
dard elutriate must be interpreted in light of mixing. This is necessary
since biological effects (which are the basis for water-quality criteria) are
a function of biologically available contaminant concentration and exposure
29
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time of the organism. In the field both concentration .and time of exposure
to a particular concentration change continuously. Since both factors will
influence the degree of biological impact, it is necessary to incorporate the
mixing expected at the disposal site in the interpretation of both chemical
and biological data. An extremely conservative approach to management of
dredged material disposal would be to disregard mixing zone considerations.*
This ignores the assimilative capacity of the receiving water. It would fre-
quently result in the application of restrictions on the operation, when, in
fact, important impacts would not occur from an unrestricted discharge opera-
tion. Disregarding mixing will result in increased cost with little concomi-
tant reduction in potential adverse impacts for most discharge operations.
32. Precise prediction of the shape and areal configuration of the
plume within which the required dilution will be achieved is a very difficult
problem involving hydrodynamic and sediment transport considerations. Al-
though developmental work is continuing on sophisticated numerical models that
will provide this capability, all are expensive because of intensive data in-
put requirements and there is no appropriate verified model that can be sug-
gested for routine use at this time. Consequently, a simplified approach for
calculating the projected surface area of the mixing zone is suggested. The
approach is based on assuming particular geometrical shapes for the disposal
plume depending upon the mode of discharge and the disposal site environment.
This approach is explained in Appendix D. In practice it is not necessary to
calculate the mixing zone for every contaminant in the discharge, but only the
one requiring the greatest dilution. All others will be encompassed within
its mixing zone.
33. Use of the simplified approach will indicate the maximum portion
(volume) of the total aquatic environment and the surface area projection that
would be considered necessary for the proposed discharge activities because it
assumes that the dredged material discharge will be completely mixed at the
disposal site and that chemical constituents measured in the standard elutri-
ate will behave conservatively following disposal. Included in the discussion
in Appendix D are methods for estimating the mixing zone for scow, hopper, and
continuous pipeline discharges, as well as for several hydrodynamic conditions
in the receiving water.
* Important sentences are italicized for emphasis.
30
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34. At this time, there is no fully satisfactory simple and rapid tech-
nique that can be used to determine the size and configuration or the accept-
ability of the mixing zone required to accommodate a discharge into an aquatic
system. However, there are several important concepts that should be consid-
ered in determining the acceptability of a mixing zone. The size of a desig-
nated mixing zone should be limited, but each mixing zone .should be tailored
to a particular receiving water body and no attempt should be made to apply a
single size limitation in any water body. In other words, a decision should
be based on a case-by-case evaluation at each proposed disposal site and the
beneficial use(s) to be protected. In addition to the considerations listed
below, a relatively larger mixing zone can be tolerated for intermittent dis-
charges (compared to continuous discharges) without having an important
adverse impact on the receiving waters. Concern over acceptability of the
calculated mixing zone increases in proportion to:
ji. Size
_b_. Configuration
jc. Proportion of volume of receiving water body occupied
^i. Proportion of cross-sectional area of receiving water body
occupied
e. Time required to achieve desired dilution for each discrete
discharge event
f_. Frequency of discharges during the dredging and disposal
operation
j>. Duration of the dredging and disposal operation
IK Proximity to municipal water intakes
_i. Proximity to sources of recharge for drinking water
aquifers
j_. Proximity to areas of high human water-contact activities
at the time of major use
Ic. Proximity to shellfish beds with commercial or recreational
importance
^. Proximity to major sport or commercial fishery areas at the
time of major use
m. Proximity to unique or concentrated fish or shellfish spawning
areas at the time of major use
n.. Proximity to unique or concentrated fish or shellfish nursery
areas at the time of major use
o_. Proximity to major fish or shellfish migration routes at the
time of major use
31
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£. Proximity to other major disposal sites or discharges at the
time of their use
35. Comrtenaement Bay area authorities have tentatively decided to deter-
mine the acceptability of mixing zones as discussed in paragraph 34 using the
following quantitative approach. Although conceptually similar approaches
could be taken elsewhere3 the approach and its quantitation would have to be
tailored specifically to local goals. The authors do not necessarily advocate
either quantitation of the guidance of paragraph 34 or its. quantitation in the
following manner since the guidance considerations may be complexly interac-
tive. The approach described below is the initial approach tentatively
selected by Commencement Bay area authorities and should not be construed as
implied guidance or a precedent for actual local authority decisions elsewhere
about the acceptability of mixing zones.
a.. Acceptability of mixing zone size is entirely case specific and
is determined by the following factors.
_b. Acceptability of mixing zone configuration is entirely case
specific and is determined by the following factors.
£. If 10 percent of less of the volume of the receiving, water body
is occupied by the mixing zone, there is cause for low concern.
If greater than 10 percent of the volume of the receiving water
body is occupied by the mixing zone, there is cause for high
concern.
cL If 10 percent or less of the cross-sectional area of the re-
ceiving water body is occupied by the mixing zone, there is
cause for low concern. If greater than 10 percent of the
cross-sectional area of the receiving water body is occupied by
the mixing zone, there is cause for high concern.
£. If the time required to achieve the desired dilution for each
discrete discahrge event is one-half or less of the interval
between discharge events, there is cause for low concern. If
the time required to achieve the desired dilution for each
discrete discharge event is greater than one-half the interval
between discahrge events, there is cause for high concern.
f_. If the frequency of discrete discharges is two or more times
the interval required to achieve the desired dilution, there is
cause for lew concern. If the frequency of discrete discharges
is less than two times the interval required to achieve the
desired dilution, there is cause for high concern.
£. If the duration of the dredging and disposal operation is
3 months or less «-here is cause for low concern^. If the dura-
tion is greater than 3 months, there is cause for high concern.
32
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h_. If the discharge point is 20 or more times the mixing zone
length from municipal water intakes, there is cause for low_
concern. If the discharge point is less than 20 times the
mixing zone length frpm municipal water intakes, there is cause
for high concern.
i. If the discharge point is 20 or more times the mixing zone
length from sources of recharge for drinking water aquifers,
there is cause for low concern. If the discharge point is
less than 20 times the mixing zone length from sources of
recharge for drinking water aquifers, there is cause for
high concern.
j_. If the discharge point is 10 or more times the mixing zone
length from areas of high human water-contact activities at the
time of major use, there is cause for tow concern. If the
discharge point is less than 10 times the mixing zone length
from such areas, there is cause for high concern.
]c. If the discharge point is 10 OP more times the mixing zone
length from shellfish beds with commercial or recreational
importance, there is cause for tow concern. If the discharge
point is less than 10 times the mixing zone length from such
areas, there is cause for high concern.
JL. If the discahrge point is 10 or more times the mixing zone
length from major sport or commercial fishing areas at the time
of major use, there is cause for tow concern. If the discharge
point is less than 10 times the mixing zone length from such
areas, there is cause for high concern.
in. If the discharge point is 10 or more times the mixing zone
length from unique or concentrated fish or shellfish spawning
areas at the time of major use, there is cause for low concern.
If the discharge point is less than 10 times the mixing zone
length away from such areas, there is cause for high concern.
ri. If the discharge point is 10 or more times the mixing zone
length from unique or concentrated fish or shellfish nursery
areas at the time of major use, there is cause for low concern.
If the discharge point is less than 10 times the mixing zone
length away from such areas, there is cause for high concern.
o_. If the discharge point is 5 or more times the mixing zone
length from major fish or shellfish migration routes at the
time of major use, there is cause for low concern. If the
discharge point is less than 5 times the mixing zone length
away from such areas, there is cause for high concern.
jp_. If the discharge point is 5 or more times the mixing zone
length from other major disposal sites or discharges at the
time of their use, there is cause for low concern. If the
discharge point is less than 5 times the mixing zone length
away from such areas, there is cause for high concern.
33
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A finding of high concern in any five or more factors leads to a DECISION OF
UNACCEPTABLE MIXING ZONE. Finding of high concern in four or less factors
leads to a DECISION OF ACCEPTABLE MIXING ZONE.
36. Several authors have defined mixing zones in terms of biological
effects. However, the mixing zone calculated by the method described should
not be equated with a zone of adverse biological impact. The basis for the
recommended approach is the fact that the effects of a discharge are a func-
tion of exposure concentration and exposure Lime. Although appropriate and
applicable water-quality criteria or bioassay results are used to define the
volume of water in which acceptable concentrations may be equalled or
exceeded, the duration of mixing zone conditions cannot be easily quantified
at this time. Therefore, the method should only be used to estimate the
volume and surface area at a disposal site within discharge concentrations
will exceed a particular value during the actual discharge.
Benthic
37. It is generally felt that if a dredged material is going to have an
environmental impact, the greater potential for impact lies with the deposited
sediment at the disposal site. This is because it is not mixed and dispersed
as rapidly or as greatly as the dissolved material; most contaminants remain
associated with the particulates; and bottom-dewlling animals live and feed in
and on the deposited material for extended perids. Therefore, the major
evaluative efforts should be placed on the deposited material. No chemical
procedures exist that will determine the environmental activity of any con-
taminants or combination of contaminants present in the solid phase of dredged
material. Therefore, animals are used in a bioassay to .provide a measurement
of environmental activity of the chemicals found in the material.
38. Scientific studies conclusively indicate that most, subaqueous dis-
posal of dredged material in low-energy aquatic environments where stable
mounding will occur will generally minimize changes in mobility of most con-
taminants (Brannon 1978; Gambrell, Khalid, and Patrick 1978; Neff, Foster, and
Slowey 1978; Wright 1977). The potential for accumulation of a contaminant in
the tissues of an organism (bioaccumulation) may be affected by exposure con-
centration and factors such as duration of exposure, salinity, water hardness,
temperature, chemcal form of the contaminant, sediment characteristics such an
organic carbon content, and the particular organism under study. The relative
importance of these factors varies. Elevated concentrations of contaminants
34
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in the ambient medium or associated sediments are not always indicative of
high levels of contaminants in tissues of benthic invertebrates or of bio-
logical effects.
39. Potential benthic impacts are best evaluated by a combined consid-
eration of total or bulk chemical analyses of the sediment to identify con-
taminants present and toxicity test(s) to determine their bioavailability. If
results of these tests do not provide sufficient information for decisionmak-
ing as discussed later in this document, a bioaccumulation test should be per-
formed to determine the potential for contaminants to accumulate in the tissues
of animals exposed to the dredged material.
40. Benthic or deposited sediment bioassays are derived from more
traditional techniques for testing contaminants in solution. While there are
many variations, those most useful for this document all involve exposure of
aquatic test organisms to deposits of whole sediment for a specified period,
followed by quantification of the responses. For reasons of regulatory
interpretation and implementation, the response of choice here is mortality
(and occasionally development or reproduction), as discussed in paragraph 25.
A technique widely used and suitable for a wide variety of aquatic macro-
organisms is given in EPA/CE (1977). This technique should be utilized to
test effects on a finfish, a crustacean, a mollusk, and an annelid acceptable
to all local interests as sufficiently sensitive and adequately representative
of the local aquatic environment. Many other exposure designs, species, and
life stages can also provide useful information and may be utilized in addition
to, or instead of, those described in EPA/CE (1977). All widely recognized
sediment bioassay techniques of regulatory utility involve toxic effects of
exposure of a few days to a few weeks. Tissues of surviving organisms which
exceed about 1 g in weight could be analyzed for contaminants at the end of
the exposure period to indicate the potential for bioaccumulation from the
sediments. The contaminants to be analyzed should be those for which there is
a sufficient cause for concern as identified in paragraph 14. In order to
best interpret bioaccumulation data, it is necessary to know concentrations in
tissues at steady-state rather than only at some intermediate point on the
uptake curve. This can be achieved by extending the exposure period until
steady-state is reached, although this can raise serious questions about the
representativeness of uptake after extended time in the laboratory unless
elaborate precautions are taken. Another alternative is to calculate
35
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steady-state tissue concentration based on sequential data collected over a
few days and a first-order uptake-depuration kinetics model. This has been
shown to give acceptable estimations of steady-state based on a few days
exposure by Branson et al. (1975) and McFarland, Gibson, and Meade (1984). A
third approach, probably the best under the circumstances where it is possible,
is the use of field data as discussed in EPA/CE (1977). There is presently no
generally accepted quantitative means of assessing potential long-term changes
in sediment effects due to possible breakdown of some organic compounds into
compounds of greater of lesser bioavailability and effect.
Upland disposal
Physicochemical conditions
41. When dredged material is placed in an upland environment in which
it does not remain water saturated, drastic physicochemical changes occur. As
soon as the dredged material is placed in a confinement area and allowed to be
exposed to the atmosphere, oxidation processes begin. The influent slurry
water initially is dark in color and reduced with little oxygen as it is dis-
charged into the confinement area from a hydraulic dredge. Mechanically
dredged sediments such as with a clamshell will have sediment pore water that
will initially be dark in color and reduced. As the slurry water passes across
the confined disposal site and approaches the discharge weir, the water becomes
oxygenated and will usually become light gray or yellowish light brown. The
color change indicates further oxidation of iron complexes in the suspended
particulates as they move across the confinement. Once disposal operations
are completed, dredged material consolidation will continue to force pore water
up and out of the dredged material and it will drain toward the discharge weir.
This drainage water will continue to become oxidized and lighter in color.
Once the surfaced pore water has been removed from the confinement, the surface
of the dredged material will become oxidized and lighter in color, such as
changing from black to light gray. The dredged material will begin to crack
as it dries out. Accumulation of salts will develop on the surface of the
dredged material and especially on the edge of the cracks. Rainfall events
will tend to dissolve and remove these salt accumulations in surface runoff.
Recent research on contaminant mobility from dredged material placed in an
upland disposal site indicates that certain metal contaminants can become
dissolved in surface runoff as dredged material dries out. During the drying
36
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process, organic complexes become oxidized and decomposed. Sulfide compounds
also become oxidized to sulfate salts. These chemical transformations could
release complexed contaminants to surface runoff, soil pore water, and leachate
through the material. In addition, plants and animals that colonize the upland
site could take up and bioaccumulate these released contaminants. Contaminant
mobility will be significantly controlled by the physicochemical changes that
occur during drying and oxidation of the dredged material.
Contaminant mobility determinations
42. Upland disposal of contaminated dredged material must be planned to
contain the dredged material within the site and restrict contaminant mobility
out of the site in order to control or minimize potential environmental
impacts. There are five possible mechanisms for transport of contaminants
from upland disposal sites:
a.. Release of contaminants in the effluent during disposal
operations.
b_. Surface runoff of contaminants in either dissolved or suspended
particulate form following disposal.
£. Leaching into ground water and surface waters.
ji. Plant uptake directly from sediments, followed by indirect
animal uptake from feeding on vegetation.
e^. Animal uptake directly from sediments.
The environmental impact of upland disposal of contaminated dredged material
may be more severe than aquatic discharge (Gambrell, Khalid, and Patrick 1978;
Jones and Lee 1978).
43. Any test protocol used to predict contaminant mobility should ac-
count for the physicochemical changes occurring in the dredged material when
placed in the specific disposal environment. The following discussion of test
protocols will address each of the above aspects in detail.
44. Effluent quality. Water-quality effects of upland disposal efflu-
ents (water discharged during active disposal operations) have been identified
as one of the greatest deficiencies in knowledge of the environmental impact
of dredged material disposal (Jones and Lee 1978). Dredged material placed in
an upland disposal area undergoes sedimentation, while clarified supernatant
waters are discharged from the site as effluent during active dredging opera-
tions. The effluent may contain levels of both dissolved and particulate-
associated contaminants. A large portion of the total contaminant level is
particulate associated.
37
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45. The standard elutriate test is sometimes used to evalaute effluent
water quality, but this test does not reflect the conditions existing in con-
fined disposal sites that influence contaminant release. A modified elutriate
test procedure, developed under the CE Long-term Effects of Dredging Opera-
tions (LEDO) Research Program (Palermo 1984), can be used to predict both the
dissolved and particulate-associated concentrations of contaminants in upland
disposal area effluents (water discharged during active disposal operations).
The laboratory test simulates contaminant release under upland disposal condi-
tions and reflects sedimentation behavior of dredged material, retention time
of the containment, and chemical environment in ponded water during active
disposal.
46. The modified elutriate test procedure is illustrated in Figure 2.
Sediment and dredging-site water are mixed to a slurry concentration equal to
/ MIX SEDIMENT AND WATER TO \
\ EXPECTED INFLUENTCONCENTRATION J
/AERATE IN «-i -VLINOEH i
I ;OH i MR i
CHEMICAL ANALYSIS
TOTAL CONCENTRATION
/ SETTLE *=OR EXPECTED MEAN FIELD \
I RETENTION TIME UP TO 24 HR MAXIMUM I
EXTRACT SUPERNATANT\
SAMPLE AND SPLIT /
SUSPENDED SOLIDS
DETERMINATION
f CENTRlFUGATtON OR 1
FILTRATION I
CHEMICAL ANALYSIS
DISSOLVED CONCENTRATION
Figure 2. Modified elutriate test procedure
38
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the expected influent concentration under field conditions. The mixed slurry
is aerated in a 4-£ cylinder for 1 hr to ensure that oxidizing conditions will
be present in the supernatant water. Following aeration, the slurry is allowed
to settle under quiescent conditions for a period equal to the expected mean
field retention time, up to a maximum of 24 hr. A sample is then extracted
from the supernatant water and analyzed for total suspended solids, and dis-
solved and total concentrations of contaminants of concern as described in
paragraph 14. The contaminant fractions of the total suspended solids may
then be calculated. Column settling tests, similar to those used for design
of disposal areas for effective settling (Palermo, Montgomery, and Poindexter
1978; Palermo 1984), are used to define the concentration of suspended solids
in the effluent for a given operational condition, i.e. ponded area, depth,
and inflow rate. Using results from both of these analyses, a prediction of
the total concentration of contaminants can be made. The predictive technique
is illustrated in Figure 3. Detailed procedures are given in Palermo (1984).
47. The acceptability of the proposed upland disposal operation can be
evaluated by comparing the predicted dissolved contaminant concentrations with
EVALUATE PERTINENT PROJECT DATA
ON DREDGE AND DISPOSAL AREA
SAMPLE DREDGING SITE
SEDIMENT AND WATER
PERFORM MODIFIED
PERFORM COLUMN
SETTLING TESTS
ELUTRIATE TESTS
ESTIMATE DISSOLVED CONCENTRATION
ESTIMATE SUSPENDED SOLIDS
OF CONTAMINANTS AND FRACTION
IN SUSPENDED SOLIDS
IN DISPOSAL AREA EFFLUENT
ESTIMATE TOTAL CONCENTRATION OF CONTAMINANTS
IN DISPOSAL AREA EFFLUENT
EVALUATE MIXING 20NE AND COMPARE
WITH STANDARDS OR CRITERIA
Figure 3. Effluent quality predictive technique
39
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applicable water-quality standards while considering an appropriate mixing
zone and the quality of the receiving water body. Where the primary adminis-
trative goal is maximum containment of contaminants, appropriate controls and
restrictions may be required to first meet water-quality criteria without a
mixing zone or, secondarily, to ensure that an acceptable mixing zone is
maintained.
48. Surface runoff quality. After dredged material has been placed in
an upland disposal site and the dewatering process has been initiated, con-
taminant mobility in rainfall-induced runoff is considered in the overall en-
vironmental impact of the dredged material being placed in a confined disposal
site. The quality of the runoff water can vary depending on the physicochemi-
cal process and the contaminants present in the dredged material. Drying and
oxidation will promote aerobic microbiological activity, which more completely
breaks down the organic component of the dredged material and oxidizes sulfide
compounds to more soluble sulfate compounds. Concurrently, reduced iron com-
pounds will become oxidized and iron oxides will be formed that can act as
metal scavengers to adsorb soluble metals and render them less soluble. The
pH of the dredged material will be affected by the amount of acid-forming com-
pounds present as well as the amount of basic compounds that can buffer acid
formation. Generally, large amounts of sulfur, organic matter, and/or pyrite
material will generate acid conditions. Basic components of dredged material
such as calcium carbonate will tend to neutralize acidity produced. The re-
sulting pH of the dredged material will depend on the relative amounts of acid-
formed and basic compounds present.
49. Runoff water quality will depend on the results of the above pro-
cesses as the dredged material dries out. For example, should there be more
acid formation than the amount of bases present to neutralize the acid, then
the dredged material will become acidic in pH. Excessive amounts of pyrite
when oxidized can reduce pH values from an initial pH 7 down to pH 3. Under
these conditions surface runoff water quality can be acid and could contain
elevated concentrations of trace metals.
50. An appropriate test for evaluating surface runoff water quality
must consider the effects of the drying process to adequately estimate and
predict runoff water quality. At present there is no single simplified labo-
ratory test to predict runoff water quality. Research was initiated in Novem-
ber 1984 to develop such a test. A laboratory test using a rainfall simulator
40
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has been developed and Is being used to predict surface runoff water quality
from dredged material as part of the CE/EPA Field Verification Program (FVP)
(Lee and Skogerboe 1983a, 1983b; Westerdahl and Skogerboe 1981). This test
protocol involves taking a sediment sample from a waterway and placing it in a
soil-bed lysimeter in its original wet reduced state. The sediment is allowed
to dry out. At intervals during the drying process, rainfall events are
applied to the lysimeter -, and surface runoff water samples are collected and
analyzed for selected water-quality parameters. Rainfall simulations are
repeated on the soil-bed lysimeter until the sediment has completely dried
out. Results of the tests can be used to predict the surface runoff water
quality that can be expected in a confined disposal site when the dredged
material dries out. From these results control measures can be formulated to
treat surface runoff water if required to minimize the environmental impact to
surrounding areas.
51. An example of the use of this test protocol can be cited (Lee and
Skogerboe 1983b). An estuarine dredged material highly contaminated with the
metals zinc, copper, cadmium, nickel, and chromium was evaluated using this
test procedure. An acid rainfall simulating typical rainfall quality at the
upland disposal site was used. Test results indicated significant solubiliza-
tion of these metals in surface runoff water after the dredged material dried
out. The pH of the dredged material became acid because of limited base neu-
tralizing compounds present and the acid rainfall applied. The oxidation of
sulfide compounds and organic complexes apparently released metals into more
soluble and mobile forms. Based on these test results, control measures were
designed to neutralize acidity and remove these metals in surface runoff
water.
52. Leachate quality. Subsurface drainage from disposal sites in an
upland environment may reach adjacent aquifers or may enter surface waters.
Fine-grained dredged material tends to form its own disposal area liner as
particles settle with percolation drainage water, but the consolidation may
require some time for self-sealing to develop. In addition, diffusion of
contaminants through fine-grained materials will continue even after the
self-sealing has stopped much of the water convection. It is surmised, but
not demonstrated, that hydrophobic organic contaminants associate with natu-
rally occurring dissolved organic carbon and thus can diffuse into ground
water beneath a site. Further work is needed to substantiate this theory.
41
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Since most contaminants potentially present in dredged material are closely
adsorbed to particles, primarily the dissolved fraction will be present in
leachates. A potential for leachate impacts exists when a dredged material
from a saltwater environment is placed in an upland site adjacent to fresh-
water aquifers or to surface waters. The site-specific nature of subsurface
conditions is the major factor in determining possible impact (Chen et al.
1978).
53. An appropriate leachate quality testing protocol must predict which
contaminants may be released in leachate and the relative degree of release.
There is presently no routinely applied testing protocol to predict leachate
quality from dredged material disposal sites. An evaluation of available
leaching procedures is needed before a leaching test protocol for confined
dredged material can be recommended. Although a wide variety of leaching or
extraction tests have been proposed for hazardous waste (Lowenbach, King, and
Cheromisinoff 1977), none have been field verified for use to evaluate leach-
ing of dredged material placed in upland disposal sites.
54. A review of the literature has indicated that theoretical models
and data on the leaching potential of dredged material are needed in order to
evaluate alternative strategies for the treatment and containment of contami-
nants in upland disposal sites. Theoretical developments that are needed in-
volve pertinent transport rate equations that describe the leaching of chemi-
cals from dewatered and consolidated dredged material. Data gaps include lack
of sufficient information on: (a) bulk transport of contaminants by seepage;
(b) contaminant leachability under various environmental conditions; and
(c) long-term geochemical consequences that alter contaminant leachability.
Leaching tests that can assist in the development of an appropriate predictive
protocol for Commencement Bay sediments are being developed at the WES.
55. Development of leachate prediction models using mass transport
equations will require information on the relative significance of intra-
particle diffusion, surface desorptlon, film diffusion, and other possible
rate-controlling mechanisms for contaminant leaching (e.g., irreversible chem-
ical reactions). Serial batch leach tests (Houle and Long 1980) can indicate
whether leaching of a sediment is an equilibrium or kinetically controlled
process. Theoretical considerations indicate that, with proper interpreta-
tion, results from serial batch leach tests can yield coefficients suitable
for modeling contaminant leaching in a confined disposal site. Predicative
42
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techniques, including serial batch leach tests, are presently being evaluated
at the WES (Hill, Myers, and Brannon 1985).
56. Column leach tests using specially constructed permeameters can
provide information needed for modeling bulk transport of contaminants in an
upland disposal site (Goerlitz 1984). The disposal site environment is sim-
ulated in a test column by passing a reference liquid or site water through
the dredged material. Comparison of batch leach test and column leach test
results can indicate the relative significance of bulk transport and diffusive
transport within a column of dredged material, and the relative importance of
film effects and nonequilibrium processes on contaminant desorption mecha-
nisms. The potential use of column and batch leaching tests for predicting
leachate quality in an upland disposal site is presently under investigation
at WES. Routine testing procedures cannot be recommended at this time.
57. Long-term geochemical changes influencing leachate quality can only
be assessed directly by long-term testing procedures. Use of large pilot-
scale leaching columns similar to those described by the Buffalo District (US
Army Engineer District, Buffalo 1983) maintained under the environmental con-
ditions that exist in a confined disposal facility will provide such infor-
mation. This leaching procedure will determine the nature of long-term con-
taminant releases and the amount of release of each contaminant over time.
Information on changes in leachate quality as a function of sediment geochem-
ical alteration under the prevailing environmental conditions will also be
provided. From this information, specific treatment of the dredged material
and/or placement of an appropriate liner can be formulated and designed into
the disposal management strategy. Alternate leaching procedures that address
long-term concern are presently under investigation and will be recommended
after appropriate testing and verification.
58. Plant uptake. After dredged material has been placed in either an
intertidal, wetland, or upland environment, plants can invade and colonize the
site. In most cases, fine-grained dredged material contains large amounts of
nitrogen and phosphorus, which promote vigorous plant growth. Elevations in
confined disposal sites can range from wetland to upland terrestrial environ-
ments. In many cases, the dredged material was placed in upland disposal
sites because contaminants were present in the dredged material. Consequently,
there is potential for movement of contaminants from the dredged material into
the environment through plants and then eventually into the food chain.
43
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59. An appropriate test for evaluating plant uptake of contaminants
from dredged material must consider the ultimate environment in which the
dredged material is placed. The physicochemical processes become extremely
important in determining the availability of contaminants for plant uptake.
60. There is a plant bioassay test protocol that was developed under
the LEDO Program based on the results of the DMRP. This procedure has been
applied to a number of contaminated dredged materials (both fresh water and
estuarine). Results obtained from these plant bioassays have provided suffi-
cient information to confirm the usefulness of the technique for predicting
the potential for plant uptake of contaminants from dredged material (Folsom
and Lee 1981, 1983; Folsom, Lee, and Preston 1981; Lee, Folsom, and Engler
1982). The procedure is presently being field verified under the CE/EPA FVP
and is being applied to a wide variety of contaminated materials such as
sewage sludge amended soils in the United States and metal mining waste con-
taminated soils in Wales, U. K.
61. The plant bioassay procedure requires taking a sample of sediment
from a waterway and placing it either in a flooded wetland environment or an
upland terrestrial environment in the laboratory. An index plant, Spartina
alterniflora for estuarine sediments and Cyperus esoulentus for freshwater
sediments, is then grown in the sediment under conditions of both wetland and
upland disposal environments. Plant growth, phytotoxicity, and bioaccumula-
tion of contaminants are monitored during the growth period. Plants are har-
vested and analyzed for contaminants. The test results indicate the potential
for plants to become contaminated when grown on the dredged material in either
a wetland or upland terrestrial environment. From the test results, appro-
priate management strategies can be formulated as to where to place a dredged
material to minimize plant uptake or how to control and manage plant species
on the site so that desirable plant species that do not take up and accumulate
contaminants are allowed to colonize the site, while undesirable plant species
are removed or eliminated.
62. There is another laboratory test being developed under the LEDO
Program that utilizes an organic extractant of dredged material to chemically
predict plant uptake of certain trace metals such as zinc, cadmium, nickel,
chromium, lead, and copper. This test procedure attempts to simulate the ca-
pacity of a plant root to extract metals from a dredged material. Field veri-
fication of this test protocol is being conducted under the CE/EPA FVP. This
44
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test procedure takes a sample of dredged material in the flooded reduced wet-
land condition and another sample that has been air dried for an upland condi-
tion. The samples are extracted for 24 hr in a modified diethylenetriamine-
pentaacetic acid (DTPA) extraction solution according to Lee, Folsom, and
Bates (1983). This solution is then filtered through a millipore filter and
the filtrate is analyzed for soluble contaminants. This procedure has been
successful in predicting plant leaf tissue contents of certain metals. There
is no existing extraction procedure that predicts plant availability of or-
ganic contaminants.
63. Animal uptake. Many animal species invade and colonize upland
dredged material disposal sites. In some cases, prolific wildlife habitats
have become established on these sites. These habitats are usually rich in
waterfowl and often become the focus of public interest through local orni-
thologists, sportsmen, and the environmentally aware public. Concern has de-
veloped recently over the potential for invertebrate animals inhabiting upland
terrestrial disposal sites to become contaminated and contribute to the
contamination of food webs associated with the site.
64. An appropriate test for evaluating animal uptake of contaminants
from dredged material must consider the ultimate environment in which the
dredged material is placed, the anticipated ecosystem developed, and the
physicochemical processes governing the biological availability of contami-
nants for animal uptake.
65. There is a recommended test protocol being tested under the CE/EPA
FVP that utilizes an earthworm as an index species to indicate toxicity and
bioaccumulation of contaminants from dredged material. In this procedure, an
earthworm is placed in sediment maintained in moist and semi-moist air-dried
environments. The toxicity and bioaccumulation of contaminants are monitored
over a 28-day period (Marquenie and Simmers 1984; Simmers, Rhett, and Lee
1983). This procedure is a modification of a procedure developed by Dr. C. A.
Edwards in England for determining the hazardous nature of manufactured chemi-
cals to be sold in the European Economic Community. Test results to date in-
dicate the terrestrial earthworm test procedure can indicate potential envi-
ronmental effects of dredged material disposal in upland environments. The
evaluative portion of the test is mainly tissue analysis rather than strictly
mortality. While the test is being established, those treatments necessary
to ensure survival for the test period (such as washing or dilution) suggest
45
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potential field site management strategies. The earthworm contaminant levels
can also be related to the food web that could exist on the site after dis-
posal. This type of test can be conducted simultaneously under optimum condi-
tions in the laboratory and in the field at or near Lhe ptoposed disposal site
to further assess the extent of contaminant mobility. This test can identify
bioavailable metals and organic contaniinarits in the material to be dredged.
Cost of conducting Lest pmluculs
66. An example of the cost and time required to conduct each test pro-
tocol is estimated in Table 1. Dollar amounts are considered as 1984 dollars.
General assumptions made to calculate costs were that the equipment and facil-
ities to conduct the test were available. Therefore, equipment costs are not
included. In addition, each sediment sample was considered to be tested in
four replicates to ensure some degree of precision. Cost to conduct the test
will vary from one part of the nation to another. Chemical analysis costs
will also vary across the nation. Cost varies with the number of samples and
the number of parameters determined. In most cases, a fewer number of compos-
ited sediment samples can be evaluated to give an indication of potential con-
taminant mobility from sediments to be dredged. In addition, a fewer number
of contaminants determined, especially organic compounds, will reduce the
chemical analysis cost. Table 1 clearly illustrates the enormous cost that
can be developed from the chemical analysis of samples. While it may cost
approximately $48,000 to obtain samples for the suite of tests, chemical
analysis costs for the sample generated could mount to between $125,000 and
$187,000. Leachate test costs are high because the leachate test is under
development and an accurate cost estimate is extremely difficult to project.
Leachate test cost should be lowered when a routine test is available. Costs
in Table 1 can be generated from the testing of only one sediment sample.
Additional sediment samples will increase these costs proportionally, rapidly
escalating the chemical analysis costs.
67. While Table 1 lists all of the test protocols that could be applied
to a contaminated sediment, the decisionmaking framework to be discussed in
the next section of this report will discuss when one or more of the test pro-
tocols should actually be conducted. From those test results, the framework
will discuss and indicate additional test protocols that should then be con-
ducted, if warranted.
46
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Contaminant detection limits
68. Table 2 presents the detection limits for contaminants identified
by Tetra Teeh (1984) as being of potential concern in Commencement Bay that
generally could be used in the chemical analyses of samples from the test
protocols. Not all of these will be identified as contaminants of real concern
in any specific sediment. All of the detection limits for water samples listed
in Table 2 are for procedures approved by EPA for compliance with requirements
of the National Pollutant Discharge Elimination System and the National Interim
Primary Drinking Water Regulations and described in 40 CFR Part 136. These
detection limits are based on relatively clean samples with few interferences.
In general, detection limits are determined primarily by sensitivity of the
analytical instrument (which is fixed), the degree of contamination, and the
mass of sample available for extraction or digestion. Most of the detection
limits for metals may be achieved using an atomic absorption spectrometer
equipped with a heated graphite furnace or an inductively coupled plasma emis-
sion spectrometer. Detection limits for mercury are obtained using a cold
vapor technique with the atomic absorption spectrometer. The detection limits
for the organics (except pesticides and PCBs) are for gas chromatography/mass
spectrometry (GC/MS) procedures using 1 I of water or 50 g of solid material.
The lower detection limits cited for pesticides and PCBs are based on
GC/Electron Capture Detection (GC/ECD) procedures. Although all of these pro-
cedures have been in use for a number of years at laboratories analyzing
environmental samples, most require analysts who are experienced in the
methodology and who are acquainted with the interferences that can alter
results. Levels of detection can be lowered by up to a factor of ten in many
cases by further concentration and cleanup of samples. Further lowering of
detection levels will require the use of more recently developed techniques
and experienced analysts.
Decisionmaking Framework
69. A decisionmaking framework is presented in detail in Appendices A
and B that utilizes the management strategy as illustrated in Figure 1 and
incorporates the results from the suite of test protocols described in
paragraphs 23-65 into ten flowcharts. These appendices discuss in detail the
47
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steps to be followed in using the flowcharts. Relevant information and data
have been compiled in a number of tables in Appendix C. The information and
data are used to make the decisions called for in the framework. Appropriate
cross referencing of paragraphs and appendix tables has been incorporated into
the flowcharts to assist the user in stepping through the framework and in and
out of associated tabular information. Terms that will be used in the frame-
work include:
a. Reference site—location from which biological and sediment or
~ water chermstry data are used for comparison to test results
from contaminated dredged material. This may vary from an
existing disposal site to an existing background site and will
be determined by a local authority decision.
b_. Local authority decision (LAD)—a decision made by local regu-
latory authorities having jurisdiction over the project in
question.
Responsibility for
local authority decisions
70. There are certain decisions that must be made initially and then
periodically within the decisionmaking framework that are the sole responsi-
bility of the local authorities. These local authority decisions (LADs) are
required to initially set specific goals to be achieved. For example, a LAD
must establish the environmental quality ultimately desired at the site and
the rate at which this goal is to be achieved. A LAD must determine the
appropriate reference site(s) for test result comparisons in the decisionmak-
ing framework in order to achieve the ultimate and intermediate goals. As
described previously, the selection of reference sites can vary from the
actual disposal site to a pristine background site. This selection is
dependent on the goal established for the area such as a goal of nondegrada-
tion (reference site is disposal site) or cleaner-than-present condition
(reference site is pristine background site) or some other goal. The clear
identification of the ultimate and intermediate goals and selection of appro-
priate references to achieve them is a crucial responsibility of the local
authorities and will influence the outcome of all test result interpretations.
In addition, LADs must be made whenever technical knowledge and understanding
are inadequate to support a scientific decision. In such cases a regulatory
decision must be made by local authorities on the basis of a combination of
scientific judgement and administrative considerations. For example, a LAD
must determine whether or not to consider mixing zones when test results
48
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exceed reference site values or water-quality criteria. Should the LAD be to
consider mixing zones and an acceptable mixing zone is available, a decision
for no restrictions on that particular aspect of the disposal might be made.
In contrast, should the LAD be not to consider mixing zones, then a decision
for restrictions might be made which will generally be more conservative but
may prove to be more costly upon implementation of the restrictions. Many of
these LADs are shown in the flowcharts as diamonds <^N . Scientific guidance
for making each LAD is provided at the appropriate points in the text. This
general guidance is appropriate for nationwide use, but the actual implementa-
tion of the general guidance must vary in different areas to meet different
local goals, objectives, and concerns. The general guidance for each LAD is
followed by a paragraph describing the initial approach to making the LAD
tentatively selected by Commencement Bay area local authorities for use at the
Commencement Bay Nearshore/Tideflats Superfund Site, Washington. For the
Commencement Bay area, the WDOE Superfund Project Manager has established the
quantitative guidance for LADs reported in this document after considering
local input from other WDOE staff, the Seattle District Corps of Engineers,
EPA Region X, and other scientists. The quantitation of the LAD guidance
facilitates objective decisionmaking, but may oversimplify complexly inter-
active considerations. Consequently, the authors have attempted to present
examples of test result interpretations in light of the tentative Commencement
Bay area authorities' LADs. The, examples are illustrations and should not be
construed as being advocated by the authors or as being final guidance.
Initial evaluation of contaminants
71. The initial evaluation determines if the sediment to be dredged is
likely to be contaminated (Figure 4). This decision is based on consideration
of available information as described in paragraph 14. The information con-
sidered in the initial evaluation also allows identification of the specific
contaminants of concern in each sediment being considered.
72. It is recommended that all potential dredging projects collect at
least one composited sediment sample from the project. This sample should be
representative of the entire depth of dredging as well as the reach of water-
way to be dredged. An example of a composited sample might be the collection
49
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IS THE SEDIMENT
CONTAMINATED?
(PARA 7 I)
. NO
(PARA 73)
Ul
o
-^—AQUATIC DISPOSAL
UPLAND DISPOSAL
-PRODUCTIVE USE
YES
(PARA 74)
WHERE SHOULD SEDIMENT
BE PLACED TO MINIMIZE
CONTAMINANT MOBILITY?
(SITE SELECTION TESTING)
EVALUATE
ALL "
OR
IS SEDIMENT ACCEPTABLE
FOR PROPOSED DISPOSAL SITE?
(SITE ACCEPTABILITY TESTING)
EVALUATE
-APPROPRIATE-
ONE
OR
, AQUATIC DISPOSAL
(APPENDIX A)
UPLAND DISPOSAL
(APPENDIX B)
AQUATIC SITE
(APPENDIX A)
UPLAND SITE
(APPENDIX B)
Figure 4. Flowchart for initial decisions for using framework
-------
of a sediment core for each 8,000 cu yd* of sediment along the waterway. This
would be the equivalent of two typical barge loads of dredged material. These
cores are then divided in half lengthwise. One half of all the cores are kept
separate while the other half of all cores are mixed to get a homogeneous com-
posited sample. This sample is then analyzed for the entire list of EPA
priority pollutants. If the composite sample indicates elevation of one or
more contaminants, then each separate remaining half core can be analyzed to
determine which sample or samples along the waterway contains contaminants.
Likewise, a composited sediment sample should be obtained from an appropriate
LAD reference site and analyzed for the entire list of EPA priority pollutants.
Further details on sediment sampling and processing procedures are reported by
Plumb (1981).
73. DECISION OF NO CONTAMINATION.** If sufficient information is avail-
able and provides no substantive reason to believe contaminants are present
above reference site levels and based on the chemical analysis of a composite
sediment sample, a DECISION FOR NO FURTHER TESTING is made. The sediment can
be dredged and disposed in an aquatic site, in an upland site, or used produc-
tively such as for marsh creation or enhancement of agricultural land with no
restrictions and no contaminant impacts on the environment. In such cases, the
selection of a disposal site is based on considerations other than potential
contaminant impacts on the environment.
74. DECISION OF SEDIMENT CONTAMINATION. If the available information
is inadequate or provides a substantive reason to believe contaminants are
present above reference site levels, then a DECISION FOR FURTHER TESTING is
made. The testing of the sediment depends on which of the two questions in
Figure 4 is being addressed. The question "In what type of disposal environ-
ment should the sediment in question be placed to minimize contaminant
mobility?" is SITE SELECTION TESTING and represents the situation where
aquatic and upland (and nearshore) disposal sites are available. The emphasis
is on selecting the disposal environment minimizing the potential for adverse
* A table of factors for converting non-Si units of measurement to SI
(metric) units is presented on page 13.
** All decisions reached on the basis of test results and interpretations are
indicated in UNDERLINED CAPITAL LETTERS.
51
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contaminant impacts from the dredged material. The second question, "Is this
sediment suitable from a contaminant perspective for placement in a particular
disposal environment?", could be considered as SITE ACCEPTABILITY TESTING and
addresses the situation that there are limitations on available disposal sites.
Therefore, the sediment is tested to determine the acceptability of a given
disposal environment for the disposal of the sediment. For example, if the
only disposal sites available are upland sites, then testing should focus on
upland disposal and not on aquatic disposal. Ultimately, the testing should
be tailored to the available disposal site. Once the appropriate question is
identified, a decision to consider AQUATIC DISPOSAL (Appendix A) or UPLAND
DISPOSAL (Appendix B) can be made. In Appendices A and B, test results are
compared to established numerical values where these are available and
appropriate for test interpretation. When such values do not exist, these
appendices provide guidance on interpreting test results in comparison to
results of the same test performed on a reference sediment selected in
accordance with paragraph 70. For each test, guidance is provided on these
bases for determining whether or not restrictions on the discharge are
required to protect against contaminant impacts or whether further evaluation
is required to determine the need for restrictions. In some case, there is
inadequate scientific knowledge to reach a decision solely on the basis of
test results, and LADs that incorporate both scientific and administrative.
judgements are required to reach a decision. In such cases, guidance is given
on evaluating the scientific considerations involved. In this manner guidance
is provided for systematically interpreting the results of each test required
to evaluate potential impacts of aquatic disposal (Appendix A) and upland
disposal (Appendix B). Applying the systematic detailed guidance of
Appendices A and/or B will lead to a decision that restrictions are or are not
required for aquatic disposal and/or upland disposal. Possible restrictions
to minimize the potential impact of aquatic disposal are discussed in
paragraphs 75-80. Cross-references in Appendix A refer to specific one(s) of
these paragraphs where appropriate. Possible restrictions to minimize the
potential impacts of upland disposal are discussed in paragraphs 81-97. These
paragraphs are referred to specifically in Appendix B wherever appropriate.
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Aquatic disposal with restrictions
75. In cases where testing protocols indicate that water column or
benthic effects will be unacceptable when conventional aquatic disposal tech-
niques are used, aquatic disposal with restrictions may be considered. This
alternative involves the use of dredging or disposal techniques that will re-
duce water column and benthic effects. Such techniques are discussed in de-
tail in US Army Engineer District, Seattle (1984) and include use of submerged
discharge points and diffusers, subaqueous confinement of material, or capping
of contaminated material with clean material, and treatment techniques. The
same basic considerations for conventional aquatic disposal site designation,
site capacity, and dispersion and mixing also apply to aquatic disposal with
restrictions.
Submerged discharge
76. The use of a submerged point of discharge reduces the area of
exposure in the water column and the amount of material suspended in the water
column and susceptible to dispersion. The use of submerged diffusers also
reduces the exit velocities for hydraulic placement, allowing more precise
placement and reducing both resuspension and spread of the discharged
material. Considerations in evaluating feasibility of a submerged discharge
and/or use of a diffuser include water depth, bottom topography, currents,
type of dredge, and site capacity. The DMRP (Barnard 1978) developed a con-
ceptual design for a submerged diffuser that has been successfully demon-
strated by European dredging interests and is now being considered for more
detailed study in the United States under the CE Dredging Operations Technical
Support (DOTS) Program.
Subaqueous confinement
77. The use of subaqueous depressions or borrow pits or the construc-
tion of subaqueous dikes can provide confinement of material reaching the bot-
tom during aquatic disposal. Such techniques reduce the areal extent of a
given disposal operation, thereby reducing both physical benthic effects and
53
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the potential for release of contaminants. Considerations in evaluating fea-
sibility of subaqueous confinement include type of 'dredge, water depth, bottom
topography, bottom sediment type, and site capacity. Subaqueous confinement
has been utilized in Europe and to a limited extent by the CE's New York Dis-
trict. Precise placement of material and use of submerged points of discharge
increase the effectiveness of subaqueous confinement.
Capping
78. Capping is the placement of a clean material over material consid-
ered contaminated. Considerations in evaluation of the feasibility of capping
include water depth, bottom topography, currents, dredged material and capping
material characteristics, and site capacity. Both the Europeans and the
Japanese have successfully used capping techniques to isolate contaminated ma-
terial in the aquatic disposal environment. Capping is also currently used by
the CE New York District and CE New England Division as a means of offsetting
the potential harm of aquatic disposal of contaminated or otherwise unaccept-
able sediments. The London Dumping Convention has accepted capping, subject
to careful monitoring and research, as a physical means of rapidly rendering
harmless contaminated material disposed in the ocean. The physical means are
essentially to seal or sequester the unacceptable material from the aquatic
environment by a covering of acceptable material.
79. The efficiency of capping in preventing the movement of contami-
nants through this seal and the degradation of the biological community by
leakage, erosion of the cover (cap), or bioturbatibn are being addressed by
research under the LEDO Program. The engineering aspects of cap design and
placement are also being addressed under this program. It is possible that
techniques and equipment can be developed that will provide a capped dredged
material disposal area as secure from potential environmental harm as upland
confined disposal areas. The capping technique for disposal of dredged mate-
rial has potential for relieving some pressure on acquiring sites for confined
disposal areas in localities where land is rapidly becoming unavailable.
Chemical/physical/biological treatment
80. Treatment of discharges into open water may be considered to reduce
certain impacts. For example, the Japanese have used an effective in-line
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dredged material treatment scheme for highly contaminated harbor sediments
(Barnard and Hand 1978). However, this strategy has not been widely applied
and its effectiveness has not been demonstrated for solution of the problem of
contaminant release during aquatic disposal.
Upland disposal with restrictions
81. Conventional confined upland disposal methods can be modified to
accommodate disposal of contaminated sediments in new, existing, and reusable
disposal areas. The design or modification of these areas must consider the
problems associated with contaminants and their effects on conventional design.
Many of the following design considerations apply to all of the implementation
options.
Site selection and design
82. Site location is an important consideration since it can mitigate
many contaminant mobilization problems. Proper site selection may reduce
surface runon and therefore contaminated runoff and contaminant release by
flooding. Ground-water contamination problems can be minimized through se-
lection of a site with natural clay foundation instead of a sandy area and
through avoidance of aquifer recharge areas (Gambrell, Khalid, and Patrick
1978).
83. Careful attention to basic site design as discussed previously will
aid in implementing many of the controls outlined. Retention time can be
increased to improve suspended solids removal and, therefore, contaminant
removal. Additional ponding depth can also improve sedimentation. Decreas-
ing the weir loading rate and improving the weir design to reduce leakage and
control the discharge rate can also reduce the suspended solids and contami-
nant concentration of the effluent.
84. Dewatering should be examined carefully before selecting a method
since dewatering promotes oxidation of the material and thereby increases the
mobility of certain contaminants (Gambrell, Khalid, and Patrick 1978). Care
must also be taken to reduce loss of contaminated sediment by erosion during
drainage and storm events.
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Available options
85. Depending on the particular dredging operation, one or more types
of restrictions may be required. The particular restriction or combination of
restrictions may eliminate certain disposal options. For the purposes of
developing a management strategy, four options are considered available for
upland disposal with restrictions. These options include:
£. Containment—dredged material and associated contaminants
are contained within the disposal site.
_b. Treatment—dredged material is modified physically, chemi-
cally, or biologically to reduce toxicity, mobility, etc.
£. Storage and rehandling—dredged material is held for a tem-
porary period at the site and later removed to another site
for ultimate disposal.
d_. Reuse—dredged material is classified and beneficial uses
are made of reclaimed materials.
Obviously, combinations of the above options are available for a particular
dredging operation.
86. Containment of contaminated dredged material can be either in an
existing or a new facility. These facilities can be designated or modified to
handle a wide variety of contaminants. Most contaminated sediments can be dis-
posed of in an existing site where special controls have been incorporated in
consideration of the restrictions discussed in paragraphs 91-97. In the case
of highly contaminated sediments, a more secure disposal facility would be
required, and, in all probability, disposal restrictions would dictate the
design of a new facility.
87. The treatment option can be associated with either existing or new
facilities. Some form of physical, chemical, or biological treatment would
probably be associated with the disposal of highly contaminated dredged mate-
rial. Treatment may also be combined with other options for disposal of
slightly to moderately contaminated dredged material in confined disposal
sites.
88. Of the four available options, storage and rehandling can serve two
beneficial functions: continued use of upland sites located close to dredging
areas and use as a rehandling facility for contaminated dredged material prior
to later disposal offsite.
89. Finally, the concept of a reuse option would incorporate beneficial
uses of materials reclaimed by the classification/separation process. Such
56
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materials could include sand and gravel or slightly contaminated construction
fill to be used for raising dikes or acceptable offsite uses.
Design considerations
90. Contaminated dredged material management includes methods for de-
watering, transporting, storing, treating, and disposing of contaminated mate-
rial. The most technically and economically effective strategy to handle con-
taminated dredged material will depend on many site-specific variables, which
include the following:
a^. Method of dredging used—hydraulic versus mechanical.
_b_. Method of dredged material transport—pipeline versus truck
or hopper or barge.
c^. Physical nature of removed material—consistency (solids/water
content) and grain-size distribution.
d_. Volume of removed material.
e^. Nature and degree of contamination; physical and chemical
characteristic of contaminants.
f_. Proximity of acceptable treatment, storage, containment,
or reuse facilities.
j>. Available land area for construction of new or expansion
of existing facilities.
Restrictions
91. Conventional confined upland disposal methods may be modified to
accommodate disposal of slightly to highly contaminated sediments. Many of
the restrictions on upland disposal that may be required are common to the
available options. Among these restrictions are:
ju Effluent-quality controls during dredging operations.
_b. Runoff water-quality controls after dredging operations.
c^. Leachate controls during and after dredging operations.
d. Control of contaminant uptake by plants and animals during
and after dredging operations.
_e_. Control of atmospheric contaminants after dredging operations.
92. Many of the contaminant controls described in the following para-
graphs are directly applicable to the control of highly contaminated sediments.
These controls will be extremely site specific. Special considerations that
57
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are based on the physical nature and chemical composition of the dredged mate-
rial will be required to effectively design a confined disposal facility. For
example, some contaminated dredged material may require in-pipeline treatment
prior to discharging the material into the containment facility. Similarly,
if the facility requires a bottom-liner system, the liner materials (synthetic
membrane or clay) must be chemically compatible (resistant) with the dredged
material to be placed on them. Special compatibility testing will be needed
for selection of appropriate liner materials. Other requirements such as
leachate detection and monitoring are likely due to the potentially adverse
environmental effects of the liner leaking.
93. Effluent controls. Effluent controls at conventional upland dis-
posal areas are generally limited to chemical clarification. The clarifica-
tion system is designed to provide additional removal of suspended solids and
associated adsorbed contaminants as described in Schroeder (1983). Additional
controls can be used to remove fine particulates that will not settle or to
remove soluble contaminants from the effluent. Examples of these technologies
are filtration, adsorption, selection ion exchange, chemical oxidation, and
biological treatment processes. Beyond chemical clarification, only limited
data exist for treatment or dredged material (Gambrell, Khalid, and Patrick
1978).
94. Runoff controls. Runoff controls at conventional sites consist of
measures to prevent the erosion of contaminated dredged material and the dis-
solution and discharge of oxidized contaminants from the surface. Control
options include maintaining ponded conditions, planting vegetation to stabilize
the surface, liming the surface to prevent acidification and to reduce dis-
solution, covering the surface with synthetic geomembranes, and/or placing a
lift of clean material to cover the contaminated dredged material (Gambrell,
Khalid, and Patrick 1978).
95. Leachate controls. Leachate controls consist of measures to
minimize ground-water pollution by preventing mobilization of soluble con-
taminants. Control measures include proper site selection, dewatering to
minimize leachate production, chemical admixing to prevent or retard leaching,
lining the bottom to prevent leakage and seepage, capping the surface to
minimize infiltration and thereby leachate production, using vegetation to
stabilize contaminants and to increase drying, and leachate collection, treat-
ment, or recycling (Gambrell, Khalid, and Patrick 1978).
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96. Control of contaminant uptake. Plant and animal contaminant uptake
controls are measures to prevent mobilization of contaminants into the food
chain. Control measures include selective vegetation to minimize contaminant
uptake, liming or chemical treatment to minimize or prevent release of con-
taminants from the material to the plants, and capping with clean sediment or
excavated material (Gambrell, Khalid, and Patrick 1978).
97- Control of atmospheric contaminants. The control of gaseous emis-
sions or dust that might present human health hazards can consist of physical
measures such as covers or vertical barriers. Control of contaminated surface
materials is another type of management or operating control to minimize
transport of contaminants offsite. Techniques for limiting wind erosion are
generally similar to those employed in dust control and include physical,
chemical, or vegetative stabilization of surface soils (CE 1983, Lee et al.
1984).
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PART III: EXAMPLE APPLICATION OF FRAMEWORK
AND INTERPRETATION OF TEST RESULTS
Disposal Environment Descriptions
98. In order to apply the decisionmaking framework and to illustrate
the integration of test results to evaluate proposed disposal options or to
select among alternatives, it is necessary to have results for the tests
described in Part II for several sediments and disposal environments. This
example utilizes a hypothetical scenario involving sediments and disposal
environments under consideration in Commencement Bay, Washington. The
disposal sites being considered are described below.
Aquatic environment
99. An aquatic site is located midway between the mouth of a major water-
way and the northern part of the bay about 3/4 of a mile from the nearest
shoreline. Depths range between 100 and 200 ft at mean lower low water (MLLW).
The site is a natural horseshoe-shaped depression; closing the fourth side
with an underwater dike would provide capacity for disposing and capping of
over 2.5 million cu yd of dredged material. Ownership of the site is with the
State of Washington, but there is little practical control over potential long-
term use of the site. The site is within 2 miles of major dredging areas. No
other major discharge sites are nearby that could result in cumulative impacts.
Water column temperatures of 9 to 12° C are usual at the site. Surface salin-
ity varies from a winter/spring low of 14 ppt to a summer high of 27 to 30 ppt.
Bottom salinity remain close to 30 ppt year round.
100. Local fishermen indicate that the area is popular for bottom fish-
ing though success is unknown. While the depths are outside the normal feeding
range of salmonids migrating over the site, the local native American tribe
indicates that the upper water column is seasonally used by drift netters.
Human activity directly affecting the site bottom has not been recorded. How-
ever, past and present use of the water surface for extensive log booming may
have influenced bottom sediment composition. Moderate to high recreational
shellfishing occurs along the nearest shoreline to the site; however, there is
no other human water-contact activity. The site is not regarded as a major
spawning or nursery area.
Upland environment
101. A 60-acre upland disposal site is bounded by roads on the north-
east and northwest and by a railroad switchyard on the southeast. The site
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was formerly a dredged material disposal area and has been filled to approxi-
mately +16 ft MLLW. The top 10 to 15 ft of the site is composed of loose fill
containing coarse sand, gravel, and debris. Under the fill is found a 10-ft-
thick layer of silt; below that is found dense sand. Filling of the site to
industrial grade found in adjacent lands would provide capacity of
100,000 cu yd; fill to +35 ft MLLW (a likely maximum) would provide capacity
for an additional 1,450,00.0 cu yd. The site is centrally located and within
1 mile from major dredging areas. Ownership is by the local Port Authority,
and the area is zoned for port industrial area development. A relatively new
warehouse and office facility exists on an elevated corner of the site. How-
ever, there is little firm regulatory control over future site use.
102. Effluent discharge from hydraulic disposal in this site would be
directed through an existing drainage canal to the nearby navigation waterway,
which also receives other major discharges. Due to recent use of this site as
a disposal area, the area contains a sparse mixture of upland grasses and
exposed sandy dredged material, but it does not serve as wildlife habitat.
The area is suspected of being a recharge area for a shallow aquifer, but
there are no wells in this aquifer at present.
Nearshore environment
103. In addition to the aquatic and upland sites described above, con-
sideration is also being given to closing off and filling Milwaukee Waterway,
a dead-end channel excavated into the shoreline of Commencement Bay. The
Milwaukee Waterway nearshore disposal area is a 30-acre navigation waterway
separated from the major bay river on the south and another actively used
waterway on the north by finger fills overlying tide flats. The top 15 to
20 ft of the finger fills along the sides, of the waterway are composed of
loose and coarse fill. Below the fill is found a layer of softer silt, varying
in thickness from 10 to 30 ft. Dense sand is further below. The bottom of
the waterway is mostly covered with approximately 5 ft of soft organic mud.
Consolidated silt (20 ft thickness) underlies the surface silt, with sand
further below. Salinity of the nearby water is similar to that of the aquatic
site. Average site elevation is -26 ft MLLW. Elevation of adjacent fill sur-
faces is +18 ft MLLW. Wet capacity (area that would remain tidally influenced
and saturated) is 1,870,000 cu yd; dry capacity is 290,000 cu yd to industrial
grade. Owned by the local Port Authority, the site is intended to be filled
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to accommodate a container terminal facility, but there is no control over
site use. The site is within 1 mile of major dredging areas.
104. There is little probability of wildlife use of the site. Little
aquifer recharge is expected here. The site is near seasonal fish migration
routes, but it is not used as a spawning or nursery area. There is no human
water-contact activity, but some recreational shell fishing occurs near the
site. There are no wells in the area.
105. If the Milwaukee Waterway is filled with dredged material, the
physicochemical conditions controlling contaminant mobility will be a com-
bination of those occurring under aquatic and upland disposal. Three distinct
physicochemical environments will develop after the filling operation and can
be described as:
a_. Upland—dry unsaturated layer.
_b_. Intermediate—partially or intermittently saturated layer.
£. Flooded—totally saturated layer.
106. Initially, all of the dredged material will be saturated, anaero-
bic, and reduced when placed in Milwaukee Waterway. After the filling opera-
tion is completed, the upper surface layer of dredged material above the high
tide elevation will become upland. The layer of dredged material between the
high tide and low tide elevations will become an intermediate layer with a
moisture content varying between saturated and unsaturated. The degree of
moisture will depend on the rate of water movement in, through, and out of
this layer. The layer of dredged material at and below the low tide elevation
will remain saturated. Potential pathways of contaminant mobility are illus-
trated in Figure 5. The three physicochemical environments that will develop
at this disposal site are also indicated.
107. The test protocols for predicting contaminant mobility at the Mil-
waukee Waterway disposal site should address the pathways illustrated in Fig-
ure 5. Test protocols similar to those described under upland disposal (para-
graphs 41-65) should be applied to dredged material placed at the Milwaukee
Waterway disposal site. The following tabulation lists the specific test
protocol and the pathway of contaminant mobility from Figure 5 addressed:
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WEIR
EFFLUENT
.QUALITY
HIGH TIDE
SOLUBLE
CONVECTION
VIA TIDAL
PUMPING
LOW TIDE
SOLUBLE
DIFFUSION
SEEPAGE
EXISTING
BOTTOM
SEEPAGE
Figure 5. Nearshore-disposal filling
of Milwaukee Waterway
Test Protocol
Effluent quality
Surface runoff quality
Leachate quality
Plant uptake
Animal uptake
Pathway of Contaminant Mobility
Effluent discharge
Runoff
Leachate
Seepage
Soluble diffusion, seepage
Soluble convection via tidal pumping
Capillary
Mobility between layers
Bioturbation
Bioturbation
These test results for sediments scheduled to be dredged in Commencement Bay
will provide appropriate information to indicate which sediments should be
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placed in the flooded, intermediate, and upland layers at the Milwaukee Water-
way disposal site in order to minimize contaminant mobility according to the
pathways illustrated in Figure 5.
Sediment Description
108. In addition to descriptions of disposal environments, example
application of the decisionmaking framework also requires test results for
several sediments. While all the tests of Part II have been performed on
various sediments, no single sediment has been analyzed by more than a few of
the tests. Therefore, Puget Sound sediments were reviewed on the basis of
existing bulk chemistry data. On the basis of these data, one sediment was
selected as a hypothetical reference sediment and three sediments with dif-
ferent concentrations of various types of contaminants were selected as
hypothetical test sediments.
109. On the basis of the considerations discussed in paragraph 14,
16 contaminants were chosen for illustrative purposes as contaminants of
concern. These contaminants are potentially environmentally important and
include a spectrum of metals and hydrocarbons, encompassing the acid
extractable, pesticide, and base-neutral fractions, including one- through
five-ring compounds. When data were not available for some of the contaminants
selected, hypothetical values were substituted that appeared reasonable on the
basis of other sediments similarly contaminated with the compounds for which
data were available.
110. The complete hypothetical bulk chemistry obtained in this manner
for the four sediments was presented to scientists familar with the various
tests of Part II. Recognizing that the results of other tests cannot accu-
rately be predicted on the basis of bulk chemistry alone, these scientists were
asked to provide hypothetical examples of possible test results that would not
seem unreasonable if the tests had actually been performed on sediments with
the hypothetical chemical concentrations. This provided the hypothetical
example values in Tables 3-21. These tables are used here only for hypothe-
tical illustration of the procedures for interpreting test results and cannot
be used for any other purpose.
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Example Interpretation of Results
111. Approach. The interpretation of hypothetical test values
presented for example test sediments A, B, and C is purely for purposes of
illustrating the decisionmaking framework. The hypothetical test results
presented in Tables 3-21 for sediments A, B, and C were interpreted according
to the guidance in Appendices A and B in order to arrive at the illustrative
results that follow. For this illustration the authors have assumed the vole
of the local authority for all LADs and have made those decisions according to
the initial approach tentatively selected by Commencement Bay area local
authorities. This approach is discussed conceptually in paragraph 69 and
described quantitatively at the appropriate points throughout the document.
However, these illustrative LAD decisions should not be construed as implied
guidance or precedents for actual LADs.
112. Discussion of possible Commencement Bay area local authority deci-
sion. Commencement Bay area authorities have discussed a variety of potential
goals for the environmental quality of Commencement Bay. While selection of
the goal for Commencement Bay has not been made, one of the alternatives dis-
cussed was the goal of returning the bay to a cleaner environment as repre-
sented by relatively untouched areas of Puget Sound. For purposes of discus-
sion and illustration in this report, the following interpretation of test
results is based on this cleaner environment goal. Accordingly, local author-
ities have selected an example reference site from among the more pristine
areas of Puget Sound. With this example goal, more dredged materials will be
found to exceed reference values by wider margins, and thus restrictions will
be required in more cases than if a less pristine reference site were chosen,
This may often result in increased costs to implement the restrictions, but
will not necessarily provide increased environmental protection. This is due
to the fact that a relatively pristine area may be able to accept a consider-
able increase in contaminants before adverse effects result, and small eleva-
tions above reference may not be environmentally important. On the other hand,
a less pristine reference area may already be sufficiently contaminated to
produce adverse results.
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Example Interpretation of Results-Sediment A
113. In the initial evaluation, Commencement Bay area authorities have
tentatively decided to require a sediment bulk chemical analysis for the
priority pollutants and a sediment toxicity test in addition to assessment of
the points discussed in paragraph 14. If any contaminant were to exceed the
concentration in- the reference sediment by 1.5 times or more (paragraph 14) or
if the sediment were more toxic than the reference sediment, testing would be
required. An advantage for doing this is that it would provide sediment-
specific data at a very early point in the decisionmaking process. However,
some disadvantages would be that the information may not be extremely useful
at this point since it would be an insufficient basis for deciding that test-
ing were not required if results were below those described above. In addi-
tion, these tests do not consider the potential for bioaccumulation and do not
consider the geochemical changes and thus the potentially very different
environmental impacts that would occur with upland disposal. Nor are these
tests sufficient to impose restrictions at this point in the de.cisionmaking
process. In addition, Commencement Bay area .authorities have tentatively
decided that no further testing for disposal in upland environments is required
for sediments containing those contaminants at concentrations equal to or less
than the normal background concentration ranges for US cropland for which
values have been established (Table C9). An alternative approach is to
assemble the available information discussed in paragraph 14 and decide whether
it is adequate to conclude there is no reason to believe the test material is
contaminated. Bulk chemical data would be specifically required in order to
assist in this evaluation. If there is insufficient information to reach this
conclusion or if there is information indicating there is reason to believe con-
taminants are present, then specific testing following the decisionmaking
framework should be initiated. Sediment A was hypothetically much more highly
contaminated with metals than any other of the test sediments (Table 14). It
was also considerably higher in sand-sized particles and lower in clay than the
reference sediment. This is probably at the outer limits of similarity in
grain sizes required for valid comparisons between test and reference sedi-
ments. These must be roughly similar in grain size for bulk chemical compari-
sons since contaminants are naturally higher and more tightly associated with
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clay than with sand. Therefore, a given contaminant concentration in clay is
of less environmental concern than the same concentration would be in sand.
Aquatic disposal-sediment A
Water column evaluation
114. Commencement Bay area authorities have tentatively decided to
place emphasis on effects as well as mass movement of contaminants. The
implementation of this is illustrated in Figure 6. The effects assessment
portion of this figure is identical to Figure Al*, except a mass loading
assessment has been added. Hypothetically, the LAD might be that site- and
sediment-specific water column testing is warranted (paragraph A2) due to the
unusually high concentrations of metals in sediment A.
115. Chemical evaluations. Hypothetically, the LAD might be to conduct
a chemistry-based evaluation of the potential for water column impacts (para-
graph A2) since water-quality criteria exist for most of the metals, which are
the primary contaminants of concern in sediment A.
116. Chemical evaluation of contaminants for which acute water-quality
criteria exist. Hypothetical elutriate test values (Table 3) for cadmium,
copper, mercury, and zinc do not require restrictions (paragraph A6b). The
hypothetical elutriate value for PCB requires a LAD (paragraph A6e). Hypo-
thetically, the LAD for PCB might be for FURTHER EVALUATION by considering
mixing, since there was high concern in relation to subparagraph A7a and
moderate concern in subparagraph A7e. When the mixing zone required to dilute
the PCB in the discharge to the acute criterion at the aquatic disposal site
(paragraphs 99 and 100) is calculated (Appendix D, sediment A), it has the
following characteristics:
au Volume of 29,160 cu ft and surface area projection of
103,023 sq ft.
_b. Plume 583 ft long by 190 ft wide parallel to shore.
£. Time to achieve dilution of 3.25 min.
jd_. One barge discharge every 3 hr around the clock.
£. Three-month dredging and disposal operation.
_f. No municipal water intakes in Commencement Bay.
* Alphanumeric identification refers similarly identified items in the
appendices.
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00
IN i |
I » I NO RESTRICTIONS I
TOXICITY: REFERENCE > TEST < LCSO
»- TOXICITY: REFERENCE < TEST < LCSO
»-TOXICITY: REFERENCE < TEST > LCSO
*-TOXICITY: REFERENCE > TEST > LCSO
NO RESTRICTIONS
>LC5oJ ^y' \S
RESTRICTIONS
Figure 6. Flowchart for Seattle decisionmaking for aquatic disposal (water
column impacts) (number near LAD is paragraph discussing LAD)
-------
£. No potential drinking water aquifers recharge from
Commencement Bay.
ti. Low human water-contact activities in Commencement Bay.
^. Moderate to high recreational shell fishing along shore
1 mile away.
j_. Year-round recreational bottom fishing at the site, seasonal
drift netting of salmonids overlaps dredging by approximately
2 weeks.
_k. Nearest major fish or shell fish spawning.or nursery areas
used during the operation are 6 miles away.
_!. Salmonids migrate over site; migration overlaps dredging by
approximately 2 weeks.
m. Nearest major discharge is sewage outfall 3 miles distant.
Hypothetically, the LAD might be that such a mixing zone is acceptable (para-
graph A9a) in view of the considerations of paragraph 34. Therefore, the
Commencement Bay area authorities might decide that there are NO RESTRICTIONS
REQUIRED to protect against potential water column impacts of contaminants of
concern for which water-quality criteria have been established.
117. Chemical evaluation of contaminants for which acute water quality
criteria do not exist. Hypothetical elutriate values (Table 3) for pyrene,
benzo(a)pyrene, hexachlorobutadiene, hexachlorobenzene, and pentachlorophenol
do not require restrictions (paragraph Alia). Hypothetical elutriate values
for arsenic, lead, naphthalene, fluorene, phenanthrene, and fluoranthene re-
quire a LAD (paragraph Allb). Hypothetically, the LAD might be for FURTHER
EVALUATION by conducting bioassays, since there was moderate concern in re-
lation to subparagraphs A8a and e.
118. Biological evaluation. Hypothetical elutriate toxicity values
(Tables 4 and 5) require a LAD for Cymatogaster (paragraph A14c), Neomysis,
Cancer and Crassostrea larvae (paragraph A14d). Hypothetically, the LAD might
be that there are RESTRICTIONS REQUIRED by the bioassay results due to high
concern in relation to subparagraphs A15a, b, and c
119. Mass loading assessment (Figure 6). Mass loading for each con-
taminant in the water column can be calculated from the water column chemical
evaluation using chemical data for both filtered and unfiltered elutriate
water samples. These calculations estimate the total amount of suspended
solids and contaminants associated with them remaining in the water column
during aquatic disposal operations. The percentage of total containment of
69
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sediment and associated contaminants at the aquatic disposal site can then
be calculated. In addition, dispersion models might be used to predict the
spread of suspended solids and associated contaminants into the aquatic envi-
ronment surrounding the disposal site. After these calculations are made and
the factors discussed under mixing zone in paragraph 34 are considered, the
LAD might be that there are NO RESTRICTIONS REQUIRED. This may be appropriate
in light of the considerations given in paragraph 116. The LAD, however,
might be that there are RESTRICTIONS REQUIRED after consideration of para-
graph 116 or from a purely administrative point of view. Some potentially
appropriate restrictions are discussed in paragraphs 75 and 76.
120. The conclusion of the hypothetical water column assessment of
paragraphs 116-119 is that there are RESTRICTIONS REQUIRED to prevent adverse
water column impacts from discharging sediment A into the aquatic environment
under the conditions evaluated. Some potentially appropriate restrictions are
described in paragraphs 79 and 76.
Benthic evaluation
121. Chemistry and toxicity evaluations. Hypothetical sediment
chemistry values for all contaminants of concern except hexachlorobutadiene
(Table 14) and hypothetical Grandifoxus toxicity values (Table 6) indicate
RESTRICTIONS REQUIRED (paragraph A20f) to prevent adverse benthic impacts from
discharging sediment A into the aquatic environment under the conditions
evaluated. Some potentially appropriate restrictions are discussed in para-
graphs 77-79. Since restrictions were required by this species, it was
unnecessary to evaluate results for other species, nor was it necessary to
evaluate bioaccumulation potential.
122. Mass loading assessment (Figure 7). Mass loading to the benthic
environment for each contaminant can be calculated from the sediment chemistry
data. These calculations might be useful as input into an inventory on the
location and amount of contaminants in Commencement Bay for future reference.
The implementation of mass loading assessment is illustrated in Figure 7,
which is similar to Figure 6 except a mass loading assessment has been added.
The Commencement Bay authorities will have to decide whether or not restric-
tions are required from a purely administrative point of view.
70
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DEPOSITED SEDIMENT IMPACTS o>
Ǥ
15
?s
EFFECTS ASSESSMENT /C\T ^
LlU
\ MASS LOADING
y •" ASS
SEDIMENT
-»- CHEMISTRY—*—
AND
TOXICITY
ESSMENT ~~
NO RESTRICTIONS |
Jk 1 9°
S\LllL-
\S NO RESTRICTIONS
RESTRICTIONS 1 f
CHEMISTRY: REFERENCE > TEST ~vfA
TOXICITY: REFERENCE > TEST < BOITN.
CHEMISTRY: REFERENCED TEST ^ '
TOXICITY: REFERENCE < TEST < 50%
CHEMISTRY: REFERENCE < TEST
TOXICITY: REFERENCE > TEST < 50%
CHEMISTRY: REFERENCE < TEST
TOXICITY: REFERENCE < TEST < 50%
CHEMISTRY: REFERENCE > TEST ^
TOXICITY: REFERENCE < TEST > 50%
CHEMISTRY: REFERENCE < TEST
TOXICITY: REFERENCE < TEST .* 50%
CHEMISTRY: REFERENCE > TEST
TOXICITY: REFERENCE > TEST > 50%
^ CHEMISTRY: REFERENCE -' TEST ^
<. A20a
Dy
BIO-
ACCUMULATION
-REFERENCED TEST < FDA-
-REFERENCE < TEST < FDA
-REFERENCE < TEST,
-REFERENCE > TEST.
-REFERENCE < TEST> FDA
-REFERENCE > TEST > FDA
TOXICITY: REFERENCE ~> TEST > 50%
Figure 7. Flowchart for decisiomnaking for aquatic disposal benthic impacts with
a mass loading assessment (number near LAD is paragraph discussing LAD)
-------
Overall conclusion
123. The conclusion of the hypothetical assessment of aquatic disposal
in paragraphs 114-122 is that there are RESTRICTIONS REQUIRED to prevent ad-
verse water column impacts, and there are RESTRICTIONS REQUIRED to prevent ad-
verse benthic impacts from discharging sediment A into the aquatic environment
under the conditions evaluated.
Upland disposal- sediment A
Effluent evaluation
124. Chemical evaluations. Hypothetically, the LAD might be to conduct
a chemistry-based evaluation of the potential for effluent impacts (para-
graph B4) since water-quality criteria exist for all but two of the metals,
which are the primary contaminants of concern in sediment A.
125. Chemical evaluation of contaminants for which acute water-quality
criteria exist. Hypothetical effluent test values (Table 12) for mercury do
not require restrictions (paragraph B6b). Hypothetical results for cadmium,
copper, zinc, and PCB require a LAD (paragraph B6e). Hypothetically, the LAD
might be that there are RESTRICTIONS REQUIRED to prevent possible contaminant
impacts of the effluent on the receiving water, due to high concern in rela-
tion to subparagraphs B8a, b, c, d, and e. Some potentially appropriate re-
strictions are discussed in paragraphs 81-93. Since restrictions were re-
quired by these test results, it is unnecessary to complete other effluent
evaluations.
126. A tentative Commencement Bay area LAD is to also evaluate unfil-
tered effluent water quality (Figure 8). Since there are no water-quality
criteria for unfiltered water, two evaluations are possible: a suspended
solids bioassay and comparison to unfiltered reference water. A suspended
solids bioassay might indicate potential contaminant impacts of effluent and
surface runoff discharge from the upland disposal site. Comparison of test
results should be made to a suspended solids bioassay of the reference sedi-
ment according to Figure 8. Discussion of the LADs for this figure are
similar to that in paragraphs B12-B18.
127- Mass loading assessment (Figure 8). Mass loading for each con-
taminant in effluent discharge can be calculated from the modified elutriate
test evaluation by using chemical data from an unfiltered modified elutriate
72
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BIOLOGICAL
xrit
EFFLUENT RECEIVING _ X.X CHEMICAL
™ATER -VATER \r"/EVALUATION
ATER
QUALITY
WATER [~
QUALITY
CRITERIA
REFERENCE • TEST-
MASS LOADING
ASSESSMENT
REFERENCE ; TEST-»-| NO RESTRICTIONS
— TOXICITV. REFERENCE v TEST . LC50
OXICITY: REFERENCE <-TEST LCSO
-TOXICITY: REFERENCE - TEST LCBO
-TOXICITY: REFERENCE, TEST _ LCBO
NO RCSTRICTIONS
.127
RESTRICTIONS
NO RESTRICTIONS
B15
AD>»-MIXING*-
-------
water sample. These calculations estimate the total amount of suspended
solids and associated contaminants discharged into the receiving water during
upland disposal operations. The percentage of total containment of dredged
material and associated contaminants in the upland disposal site can then be
calculated. In addition, dispersion models might be used to predict the
potential spread of suspended solids and associated contaminants into the
aquatic environment receiving the effluent discharge. After these calcula-
tions are made and the factors discussed under mixing zone in paragraphs 34
and 35 are considered, the LAD might be that there are NO RESTRICTIONS RE-
QUIRED. This may be appropriate in light of the considerations given in para-
graphs 34-35. The LAD, however, might be that there are RESTRICTIONS REQUIRED
after consideration of paragraphs 34-35 or from a purely administrative point
of view. This assessment was not necessary since restrictions were required
in paragraph 125.
Surface runoff evaluation
128. Chemical evaluations. Hypothetically, the LAD might be to conduct
a chemistry-based evaluation of the potential for surface runoff impacts (para-
graph B19) since water-quality criteria exist for all but two of the metals,
which are the primary contaminants of concern in sediment A.
129. Chemical evaluation of contaminants for which acute water-quality
criteria exist. Hypothetical surface runoff test values (Table 13) for cad-
mium, copper, mercury, zinc, and PCB require a LAD (paragraph B21e). Hypo-
thetically, the LAD might be that there are RESTRICTIONS REQUIRED to prevent
possible contaminant impacts of the surface runoff on the receiving water,
due to high concern in relation to subparagraphs B23a, b, c, and e, and mod-
erate concern in relation to subparagraph B23e. Some potentially appropriate
restrictions are discussed in paragraphs 81-91 and 94. Since restrictions
were required by these test results, it is unnecessary to complete other sur-
face runoff evaluatons.
130. Mass loading assessment (Figure 9). Mass loading for each con-
taminant in surface runoff discharges can be calculated from the surface run-
off test evaluation by using chemical data from an unfiltered runoff water
sample. These calculations estimate the total amount of suspended solids and
associated contaminants discharged into the receiving water during a storm
74
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BIOLOGICAL
B19
SURFACE RECEIVING /^\ CHEMICAL
RUNOFF WATER ^N^/EVALUATION
WATER [~
QUALITY ^
CRITERIA
REFERENCE TEST-
REFEHENCE - TEST
I NO RESTRICTIONS I
\ADx
ASSESSMENT
RESTRICTIONS
]
-TOXICITV. REFERENCED TEST < LCSO
.TOXICITV. REFERENCE < TEST t LCSO
• TOXICITV: REFERENCE < TEST • LCSO-
-TOXICITY: REFERENCE j TEST > LCSO
NO RESTRICTIONS
B32
RESTRICTIONS
Figure 9. Flowchart for decisionmaking for unfiltered surface runoff water quality
with mass loading assessment (number near LAD is paragraph discussing LAD)
-------
event at the upland disposal site. The percentage of total containment of
dredged material and associated contaminants in the upland disposal site can
then be calculated. In addition, dispersion models might be used to predict
the potential spread of suspended solids and associated contaminants into
the aquatic environment receiving the surface runoff discharge. After these
calculations are made and the factors discussed under mixing zone in para-
graphs 34 and 35 are considered, the LAD might be that there are NO RESTRIC-
TIONS REQUIRED. This may be appropriate in light of the considerations given
in paragraphs 34-35. The LAD, however, might be that there are RESTRICTIONS
REQUIRED after consideration of paragraphs 34-35 or from a purely adminis-
trative point of view. This assessment was not necessary since restrictions
were required in paragraph 129.
Leachate quality evaluation
131. The local authority may choose to consider leachate quality in re-
lation to drinking water since the area is suspected of being a recharge area
for a shallow aquifer (paragraph 102). A LAD might be to conduct a leachate
test due to the unusually higher concentration of metals in sediment A than in
the reference sediment. Hypothetical test results (Table 15) indicate leach-
ate concentrations of arsenic, cadmium, copper-, lead, and mercury from sedi-
ment A that exceed the reference water and drinking water standards and there-
fore lead to a DECISION FOR RESTRICTIONS (paragraph B51c). In the case of a
nonpotable ground water, the LAD might consider potential water column impacts
(Figure B5) by following the approach discussed in paragraphs 55-60.
Plant uptake evaluation
132. Hypothetically, the LAD might be that a DTPA extraction test is
warranted (paragraph 62) due to the unusually high concentrations of metals in
sediment A. Hypothetical test results (Table 16) indicate a potential for
plant uptake of cadmium, copper, lead, mercury, and zinc (paragraph B63d).
High concerns are indicated for paragraphs B65a, b, and c since these metals
represent more than 25 percent of the metals of concern and all metals
(especially cadmium and mercury, which are ranked 4 and 6) were greater than
10 times higher than reference values. These high concerns lead to a DECISION
FOR FURTHER EVALUATION by conducting a plant bioassay (paragraphs 60 and 61).
76
-------
133. Hypothetically, plant yield results (Table 17) lead to a LOCAL
AUTHORITY DECISION (paragraph B66b). The LAD might be a DECISION FOR FURTHER
EVALUATION by conducting a bioaccumulation evaluation (paragraph 61) is war-
ranted. Bioaccumulation results (Table 17) indicate plant uptake of cadmium
and zinc above demonstrated effect levels (Table C5) and cadmium above FDA-
type levels (Table C8) which lead to a DECISION FOR RESTRICTIONS (para-
graph B68d). The LAD could have been to require restrictions rather than
conduct a bioaccumulation evaluation.
Animal uptake evaluation
134. Hypothetically, the LAD might be that an animal uptake/bioassay
test is warranted (paragraph 65) due to the unusually high concentrations of
metals in sediment A. Hypothetical test results of 98-percent toxicity
(Table 18) and growth reductions (Table 19) lead to a DECISION FOR RESTRIC-
TIONS (paragraph B74a) and no further testing required.
Human exposure evaluations
135. Hypothetically, concentrations of lead and mercury in sediment A
(Table 14) exceed tabulated values for soil ingestion of lead and mercury
(Tables C9 and CIO) and therefore lead to a DECISION FOR RESTRICTIONS (para-
graph B80b).
Nearshore disposal-sediment A
136. The foregoing test results and decisions for upland disposal will
apply equally well to the nearshore disposal site. An additional aspect that
needs to be considered is the leachate quality of dredged material placed in
the saturated zone of the nearshore site (Table 20). Sediment A will be dis-
cussed in relationship to the previous paragraphs.
137. Restrictions would be required for effluent discharge (para-
graphs 124-127). Restrictions will also be required for surface runoff
(paragraphs 128-130). Leachates from the upland portions of the site will re-
quire restrictions (paragraph 131). Hypothetical test results of sediment A
leachate from the saturated zone (Table 20) indicate As concentrations sub-
stantially greater than reference sediment concentrations and leads to a LOCAL
AUTHORITY DECISION (paragraph B42b). The Commencement Bay area authorities
77
-------
might choose to reach a DECISION FOR RESTRICTIONS due to sediment A leachate
containing arsenic at a substantial margin above reference concentrations.
Restrictions would be required for sediment A for plant uptake concerns
(paragraphs 132 and 133), animal uptake (paragraph 134) and for human exposure
(paragraph 135).
Example Interpretation of Results-Sediment B
Aquatic disposal-sediment B
Water column evaluation
138. Hypothetically, the LAD might be that site- and sediment-specific
water column testing is warranted (paragraph A2).
139. Chemical evaluations. Hypothetically, a LAD might be that
chemistry-based evaluations of the potential for water column impacts are in-
appropriate (paragraph A4), due to concern over possible interactive effects
of the multiple contaminants of concern (particularly several organics) hypo-
thetically present in sediment B (Table 14). Therefore, a biological evalua-
tion would be appropriate.
140. Biological evaluations. Hypothetical elutriate toxicity values
(Tables 4 and 5) require a LAD for Cymatogastery NeomysiSj Cancer, and Cras-
sostrea larvae (paragraph A14c). Hypothetically, the LAD might be that there
are RESTRICTIONS REQUIRED by the bioassay results due to high concern in re-
lation to subparagraphs A16a, b, and c.
141. The conclusion of the hypothetical water column assessment of
paragraphs 138-140 is that there are RESTRICTIONS REQUIRED to prevent adverse
water column impacts from discharging sediment B into the aquatic environment
under the conditions evaluated. Some potentially appropriate restrictions are
described in paragraphs 75 and 76.
Benthic evaluation
142. Chemistry and toxicity evaluation. Hypothetical sediment chem-
istry values for all contaminants of concern (Table 14) and hypothetical
PandaluSj Hacoma, Neanthes, and Parophrys toxicity values (Table 7) and hypo-
thetical Grandifoxus (Table 6) toxicity values require FURTHER EVALUATION by
assessing the potential for bioaccumulation (paragraph A20c or d).
78
-------
143. Bioaccumulation evaluation. Hypothetical contaminant concentra-
tion of arsenic, cadmium, and mercury in Macoma (Table 8), arsenic in Pandalus
(Table 9), cadmium in Neanthes (Table 10), and arsenic, cadmium, and lead in
Parophrys (Table 11) exceed FDA-type limits and indicate RESTRICTIONS REQUIRED
(paragraph A21b) to prevent adverse benthic impacts from discharging sediment B
into the aquatic environment under the conditions evaluated. Some potentially
appropriate restrictions are discussed in paragraphs 75-80. In practice, the
bioaccumulation assessment can be halted as soon as one contaminant-species
combination gives results requiring restrictions; all were identified above for.
the sake of completeness for illustrative purposes.
Overall conclusion
144. The conclusion of the hypothetical assessment of aquatic disposal
in paragraphs 138-143 is that there are RESTRICTIONS REQUIRED to prevent ad-
verse water column impacts, and there are RESTRICTIONS REQUIRED to prevent
adverse benthic impacts from discharging sediment B into the aquatic environ-
ment under the conditions evaluated.
Upland disposal- sediment B
Effluent evaluation
145. Chemical evaluation. Hypothetically, a LAD might be that
chemistry-based evaluations of the potential for effluent impacts are inap-
propriate (paragraph B4) due to concern over possible interactive effects of
multiple contaminants of concern (particularly several organic compounds)
hypothetically present in sediment B (Table 14). Therefore, a biological
evaluation would be appropriate,
146. Biological evaluation. Hypothetical effluent (modified elutriate)
toxicity values (Table 21) require a LAD for Cymatogastev, Neomysisf Cancer
larvae (paragraph B14c), and Crassastrea larvae (paragraph B14d). Hypothet-
ically, the LAD might be for FURTHER EVALUATION by considering mixing, since
there is high concern in relation to subparagraphs B16a and b, and only moder-
ate concern in relation to subparagraphs B16c. When the mixing zone required
to bring the discharge to less than the LC50 for Crassostrea (the species
requiring the greatest dilution volume) at the upland disposal site is calcu-
lated (Appendix D, sediment B effluent mixing zone), it has the following
characteristics:
79
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_a. Volume of 13 cu ft/sec dilution water required.
b^. Surface area projection negligibly small.
£. Plume length and width negligibly small.
cL intermittant discharge with storms after completion of the
dredging and disposal operation.
_e. No municipal water intakes in Commencement Bay.
f_. No potential drinking water aquifers recharge from the
waterway or Commencement Bay.
\
£. No human water contact activities in waterway, low activity
in Commencement Bay.
li. Light recreational shell fishing along shore outside waterway
about 3 miles away.
±^. No fishing in waterway, year-round sport bottom fishing and
seasonal drift netting of salmonids outside waterway about
3 miles away.
j_. Nearest fish migration, spawning or nursery area outside
waterway about 5 miles away; migration overlaps dredging
by approximately 2 weeks.
Ic. Major sewage and industrial discharges and nonpoint industrial
runoff into nearby waterway.
Hypothetically, the LAD might be that such a mixing zone is acceptable (para-
graph B17a) in view of the considerations of paragraph 34, and thus restric-
tions are not required by the bioassay results.
147. The conclusion of the hypothetical effluent (modified elutriate)
assessment of paragraphs 145 and 146 is that there are NO RESTRICTIONS
REQUIRED to prevent adverse impacts from the effluent of sediment B placed in
the upland disposal site.
Surface runoff evaluation
148. Chemical evaluations. Hypothetically, the LAD might be to conduct
a chemistry-based evaluation of the potential for surface runoff impacts
(paragraph B19).
149. Chemical evaluation of contaminants for which acute water-quality
criteria exist. Hypothetical surface runoff values (Table 13) for cadmium,
mercury, and zinc do not require restrictions (paragraph B21b). The hypothet-
ical surface runoff value for copper and PCB require a LAD (paragraph B21e).
Hypothetically, the LAD might be for FURTHER EVALUATION by considering mixing
due to high concern in relation to subparagraphs B23a and e, and moderate
concern in relation to subparagraphs B23b, c, and d. When the mixing zone
80
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required to dilute PCB (the contaminant of concern requiring the greatest
dilution volume) in the discharge to the acute criterion at the upland disposa
site (paragraphs 99-102) is calculated (Appendix D, sediment B surface runoff
mixing zone), it has the following characteristics:
a.. Volume of 2,844 cu ft/sec dilution water required.
_b. Surface area projection negligibly small.
£. Plume width 47 ft and length negligibly small.
d. Intermittant discharge with storms after completion of the
dredging and disposal operation.
£. No municipal water intakes in Commencement Bay.
_f. No potential drinking water aquifers recharge from the
waterway or Commencement Bay.
£. No human water contact activities in waterway, low activity
in Commencement Bay.
h_. Light recreational shell fishing along shore outside waterway
about 3 miles away.
jL. No fishing in waterway, year-round sport bottom fishing and
seasonal drift netting of salmonids outside waterway about
3 miles away.
j_. Nearest fish migration, spawning or nursery area outside
waterway about 5 miles away; migration overlaps dredging
by approximately 2 weeks.
It. Major sewage and industrial discharges and nonpoint industrial
runoff into nearby waterway.
Hypothetically, the LAD might be that such a mixing zone is acceptable (para-
graph B25a) in view if the considerations of paragraph 34, and thus restric-
tions are not required by the results in relation to criteria.
150. Chemical evaluation of contaminants for which acute water-quality
criteria do not exist. Hypothetical surface runoff values (Table 13) do not
require restrictions for naphthalene, fluorene, phenanthrene, benzo(a)pyrene,
hexachlorobutadiene, hexachlorobenzene, and pentachlorophenol (para-
graph B26a). Hypothetical surface runoff values require a LAD for arsenic,
lead, fluoranthene, and pyrene (paragraph B26b). Hypothetically, the LAD
might be that restrictions are not required due to low concern in relation to
subparagraphs B23a, c, and e. The conclusion of the hypothetical surface
runoff assessments of paragraphs 148-150 is that there are NO RESTRICTIONS
REQUIRED to prevent adverse impacts from the surface runoff of sediment B
placed in the upland disposal site.
81
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Leachate quality evaluation
151. The local authority may choose to consider leachate quality in re-
lation to drinking water since the area is suspected of being a recharge area
for a shallow aquifer (paragraph 102). A LAD might be to conduct a leachate
test due to the higher concentrations of metals in sediment B than in the ref-
erence sediment. Hypothetical test results (Table 15) indicate leachate con-
centrations of metals are greater than reference ground water and equal to
or less than drinking water standards and therefore lead to a LOCAL AUTHORITY
DECISION (paragraph B51d). The local authority may choose to reach a DECISION
FOR RESTRICTIONS due to leachate cadmium concentration being equal to the
drinking .water standard.
Plant uptake evaluation
152. Hypothetically, the LAD might be that a DTPA extraction test is
warranted (paragraph 62) due to the higher concentration of metals in sedi-
ment B than in the reference sediment. Hypothetical test results (Table 16)
indicate a potential for plant uptake of cadmium, copper, lead, and zinc
(paragraph B63d). High concerns are indicated for paragraphs B65a, b, and c
since these metals represent four out of six metals or 67 percent; these
metals are more than 10 times reference and cadmium is ranked 4 in toxico-
logical importance (Table C3). These high concerns lead to a DECISION FOR
FURTHER EVALUATION by conducting a plant bioassay (paragraphs 60 and 61).
153. Hypothetically, plant yield results (Table 17) lead to a DECISION
FOR FURTHER EVALUATIONS (paragraph B66a) by conducting a bioaccumulation eval-
uation. Bioaccumulation results (Table 17) lead to a LOCAL AUTHORITY DECISION
(paragraph B681) and indicate high concern in two factors (paragraphs B70a and
d). Plant content of arsenic, cadmium, and copper (three out of six metals or
50 percent) was above reference and cadmium is ranked 4 in toxicological impor-
tance (Table C3). Two high concerns in plant contents is sufficient to lead
to a DECISION FOR RESTRICTIONS (paragraph B70a). In addition, if the Commence
Bay area authorities desire to fully evaluate the potential for mass movement
of contaminants into plants, total uptake could be considered. Total uptake
results (Table 17) indicate high concern in two factors (paragraph B72a and c).
Total uptake of arsenic, cadmium, and copper (three out of six metals or
82
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50 percent) was greater than the reference. Cadmium is ranked 4 in toxicolog-
ical importance (Table C3). Two high concerns lead to a DECISION FOR RESTRIC-
TIONS (paragraph B72).
Animal uptake evaluation
154. Hypothetically, the LAD might be that an animal uptake/bioassay
test is warranted (paragraph 65) due to the higher concentration of metals in
sediment B than in the reference sediment. Hypothetical test results of
1-percent toxicity (Table 18) leads to a DECISION FOR FURTHER EVALUATION
(paragraph B74b) by conducting a bioaccumulation evaluation. Bioaccumulation
results (Table 19) indicate animal contents for arsenic, cadmium, copper,
lead, and zinc that exceed FDA-type limits (Table Cl) and therefore lead to a
DECISION FOR RESTRICTIONS (paragraph B75b).
Human exposure evaluation
155. Hypothetically, concentrations of metals in sediment B (Table 14)
are less than tabulated values for soil-ingested metals (Tables C9 and CIO)
and therefore lead to a DECISION OF NO RESTRICTIONS (paragraph B80a).
Nearshore disposal-sediment B
156. The foregoing test results and decisions for upland disposal will
apply equally well to the nearshore disposal site. An additional aspect that
needs to be considered is the leachate quality of dredged material placed in
the saturated zone of the nearshore site (Table 20). Sediment B will be dis-
cussed in relationship to the previous paragraphs.
157. No restrictions would be required for effluent discharges (para-
graphs 145-147). No restrictions would be required for surface runoff dis-
charge (paragraphs 148-150). Leachate for the upland portion of the site will
require restrictions (paragraph 151). Hypothetical test results (Table 20) of
sediment B leachate from the saturated zone indicates PCB concentrations sub-
stantially above the chronic criteria. Therefore, these results lead to a
LOCAL AUTHORITY DECISION (paragraph B37d). The Commence Bay area authorities
might choose to reach a DECISION FOR RESTRICTIONS due to sediment B leachate
containing PCBs at a substantial margin above the chronic criteria (Table 20).
RESTRICTIONS would be required for plant uptake (paragraphs 152 and 153) and
83
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for animal uptake (paragraph ISA). There would be NO RESTRICTIONS required
for human exposure concerns (paragraph 155).
Example Interpretation of Results-Sediment C
Aquatic disposal-sediment C
Water column evaluation
158. Hypothetically, a LAD might be that site- and sediment-specific
water column testing is warranted (paragraph A2).
159. Chemical evaluation. Hypothetically, a LAD might be to conduct a
chemistry-based evaluation of the potential for water column impacts (para-
graph A4) since water-quality criteria exist for many of the contaminants of
concern present in highest concentrations.
160. Chemical evaluation of contaminants for which acute water-quality
criteria exist. Hypothetical elutriate test values (Table 3) do not require
restrictions for mercury (paragraph A6a), cadmium, copper, zinc, and PCB
(paragraph A6e).
161. Chemical evaluation of contaminants for which acute water-quality
criteria do not exist. Hypothetical elutriate test values (Table 3) for arse-
nic, naphthylene, fluorene, phenanthrene, fluoranthene, pyrene* benzo(a)pyrene,
hexacholorbutaodiene, hexachlorobenzene, and pentachlorophenol do not require
restrictions (paragraph Alia). The hypothetical elutriate value for lead re-
quires a LAD (paragraph Allb). Hypothetically, the LAD might be that restric-
tions are not required since there was low concern in relation to subpara-
graphs A8a, b, and e.
162. Biological evaluation. Biology-based evaluations were not origi-
nally selected (paragraph A4), and were not indicated by test results (para-
graph A12).
163. The conclusions of the hypothetical water column assessment of
paragraphs 158-161 is that there are NO RESTRICTIONS REQUIRED to prevent ad-
verse water column impacts from discharging sediment C into the aquatic envi-
ronment under the conditions evaluated.
Benthic evaluation
164. Chemistry and toxicity evaluation. Hypothetical sediment chemistry
values for all contaminants of concern (Table 14) and hypothetical Pandalus,
84
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Macoma, Neanthes, and Parophrys toxicity values (Table 7) and hypothetical
Grandifoxus toxicity values (Table 6) require FURTHER EVALUATION by assessing
the potential for bioaccumulation (paragraph A20c or d).
165. Bioaccumulation evaluation. Hypothetical concentrations of most
contaminants of concern in tissues of Macoma, Pandalus, Neanthes, and
Parophrys (Tables 8-11) require a LAD (paragraph A21d or e). Hypothetically,
the LAD might be that restrictions are required due to high concern in rela-
tion to subparagraphs A23a, b, c, d, e, f, j, and 1. Some potentially appro-
priate restrictions are described in paragraphs 75-80.
Overall conclusion
166. The conclusion of the hypothetical assessment of aquatic disposal
in paragraphs 158-165 is that there are NO RESTRICTIONS REQUIRED to prevent
adverse water column impacts, and there are RESTRICTIONS REQUIRED to prevent
adverse benthic impacts from discharging sediment C into the aquatic environ-
ment under the conditions evaluated.
Upland disposal-sediment C
Effluent evaluation
167. Chemical evaluation. Hypothetically, the LAD might be to conduct
a chemistry-based evaluation of the potential for effluent impacts (para-
graph B4) since water-quality criteria exist for many of the contaminants of
concern present in the sediment in highest concentrations.
168. Chemical evaluation of contaminants for which acute water-quality
criteria exist. Hypothetical effluent test values (Table 12) for cadmium and
mercury (paragraph B6a) and zinc (paragraph B6b) do not require restrictions.
Hypothetical effluent values require a LAD for copper and PCS (paragraph B6e).
Hypothetically, the LAD might be for FURTHER EVALUATION by considering mixing
due to moderate concern in relation to subparagraphs B8a, c, d, and e and low'
concern in relation to subparagraph B8b. When the mixing zone required to
dilute PCB (the contaminant of concern requiring the greatest dilution volume)
in the discharge to the acute criterion at the upland disposal site (para-
graphs 101 and 102) is calculated (Appendix D, sediment c), it has the follow-
ing characteristics:
a. Volume of 473 cu ft/sec dilution water required.
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_b_. Surface area projection is negligibly small.
£. Plume 8 ft wide and of negligible length.
d^ Intermittant discharge with storms after completion of the
dredging and disposal operation.
£. No municipal water intakes in Commencement Bay.
_f. No potential drinking water aquifers recharge from the
waterway or Commencement Bay.
£. No human water contact activities in waterway, low activity
in Commencement Bay.
h_. Light recreational shell fishing along shore outside waterway
about 3 miles away.
i_. No fishing in waterway, year-round sport bottom fishing and
seasonal drift netting of salmonids outside waterway about
3 miles away.
j_. Nearest fish migration, spawning or nursery area outside
waterway about 5 miles away; migration overlaps dredging
by approximately 2 weeks.
_k. Major sewage and industrial discharges and nonpoint industrial
runoff into nearby waterway.
Hypothetically; the LAD might be that such a mixing zone is acceptable (para-
graph B9a) in view of the considerations of paragraph 34, and thus restric-
tions are not required by the results in relation to criteria.
169. Chemical evaluation of contaminants for which acute water-quality
criteria do not exist. Hypothetical effluent values (Table 12) for naphtha-
lene, fluorene, phenanthrene, fluoranthehe, pyrene, benzo(a)pyrene, hexa-
chlorobutadiene, and hexachlorobenzene do not require restrictions (para-
graph Blla). Hypothetical effluent values require a LAD for arsenic, lead,
and pentachlorophenol (paragraph Bllb). Hypothetically, the LAD might be for
FURTHER EVALUATION by conducting bioassays due to moderate concern in relation
to subparagraphs B8a and e and low concern in relation to subparagraph B8c.
170. Biological evaluation. Hypothetical effluent (modified elutriate)
toxicity values Neomysis. and Crassostrea (Table 21) do not require restric-
tions (paragraph B14a). Results for Cancer require a LAD (paragraph B14c).
171. The conclusion of the hypothetical effluent (modified elutriate)
assessment of paragraphs 167-170 is that there are NO RESTRICTIONS REQUIRED to
prevent adverse impacts from the effluent of sediment C placed in the upland
disposal site.
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Surface runoff evaluation
172. Chemical evaluations. Hypothetically, the LAD might be to conduct
a chemistry-based evaluation of the potential for surface runoff impacts
(paragraph B19).
173. Chemical evaluation of contaminants for which acute water-quality
criteria exist. Hypothetical surface runoff values (Table 13) do not require
restrictions for cadmium, mercury, PCB (paragraph B21a), copper and zinc
(paragraph B21b).
174. Chemical evaluation of contaminants for which acute water-quality
criteria do not exist. Hypothetical surface runoff values (Table 13) for
arsenic, naphthalene, fluorene, phenanthrene, f luoranthene, pyrene, benzo(a)-
pyrene, hexachlorobutadiene, hexachlorobenzene , and pentachlorophenol do not
require restrictions (paragraph B26a) . Hypothetical values require a LAD for
lead (paragraph B26b) . Hypothetically, the LAD might be that there are NO
RESTRICTIONS REQUIRED due to low concern in relation to subparagraphs B23a and
Leachate quality evaluation
175. The local authority may choose to consider leachate quality in re-
lation to potable ground water since the area is suspected of being a recharge
area for a shallow aquifer (paragraph 102). A LAD might be to conduct a leach-
ate test due to the higher concentrations of metals in sediment C than in the
reference sediment. Hypothetical test results (Table 15) indicate leachate
concentrations of metals are greater than reference ground water and less than
drinking water standards and therefore lead to a LOCAL AUTHORITY DECISION
(paragraph B51d). Leachate results indicate a high concern in one factor
(paragraph B31) since four out of six metals or 67 percent exceeded reference.
Only one metal (zinc) was 25 times reference representing a moderate concern
but zinc is ranked 1 in toxicological importance and therefore is a low con-
cern. Based on these results, the local authority may choose to reach a
DECISION FOR NO RESTRICTIONS.
Plant uptake evaluations
176. Hypothetically, the LAD might be that a DTPA extraction test is
warranted (paragraph 62) due to the higher concentrations of metals in sedi-
ment C than the reference sediment. Hypothetical test results (Table 16)
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indicate a slight potential for plant uptake of cadmium, copper, lead, and
zinc and leads to a DECISION FOR FURTHER EVALUATION (paragraph B63d). Hypo-
thetically, plant yield results (Table 17) leads to a DECISION FOR FURTHER
EVALUATION (paragraph B66a) by conducting the bioaccumulation evaluation
(paragraph B68). Bioaccumulation results (Table 17) indicates all tissue
concentration of contaminants of concern are equal to or less than the ref-
erence and demonstrated effects lead to a DECISION OF NO RESTRICTIONS (para-
graph B68a). In addition, the Commence Bay area authorities should fully
evaluate the potential for mass movement of contaminants into plants by con-
sidering total uptake, even though bioaccumulation was equal to or less than
the reference. Total uptake of all contaminants of concern were less than
that of the reference, which leads to a DECISION OF NO RESTRICTIONS.
Animal uptake evaluation
177. Hypothetically, the LAD might be that an animal uptake bioassay
test is warranted (paragraph 65) due to the higher concentration of metals in
sediment C than in the reference sediment. Hypothetical test results of
0 percent toxicity (Table 18) leads to a DECISION FOR FURTHER EVALUATION
(paragraph B74b) by conducting a bioaccumulation evaluation. Bioaccumulation
results (Table 19) indicate animal contents for arsenic, cadmium, and lead
that exceed FDA-type limits (Table Cl) and therefore lead to a DECISION FOR
RESTRICTIONS (paragraph B75b).
Human exposure evaluation
178. Hypothetically, concentrations of metals in sediment C (Table 14)
are less than tabulated values for soil-ingested metals (Table C9) and there-
fore lead to a DECISION OF NO RESTRICTIONS (paragraph B80a).
Nearshore disposal
179. The foregoing test results and decisions for upland disposal will
apply equally well to the nearshore disposal site. An additional aspect that
needs to be considered is the leachate quality of dredged material placed in
the saturated zone of the nearshore site (Table 20). Each sediment will be
discussed in relationship to the previous paragraphs.
180. NO RESTRICTIONS would be required for effluent discharge (para-
graphs 167-171) or for surface runoff discharges (paragraphs 172-174).
88
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NO RESTRICTIONS would be required for leachates from sediment C (para-
graph 175) and based on the hypothetical test results in Table 20. These
latter test results would generally lead to a DECISION OF NO RESTRICTIONS
(paragraph B37a). However, a tentative Commencement Bay LAD would consider
impacts of nonpotable ground water resurfacing and resulting in an accumula-
tion of previously dissolved contaminants in surface sediments at the point of
resurfacing (paragraph B59). Benthic impact tests on the original sediment C
might be considered as the worst possible case for recontamination of surface
sediments. Based on the benthic bioaccumulation tests described above,
RESTRICTIONS would be required for leachate to protect against potential con-
taminant bioaccumulation in benthic organisms according to the above scenario.
NO RESTRICTIONS would be required for plant uptake (paragraph 176). RESTRIC-
TIONS on animal uptake would be required (paragraph 177). NO RESTRICTIONS
would be required for human exposure (paragraph 178).
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PART IV: SUMMARY
181. Parts I and II of this document describe appropriate types of
tests and the evaluation and interpretation of test results. These parts can
be applied to any dredged material. Part III is a hypothetical example of the
application of Parts I and II to Commencement Bay, Washington, and is useful
in conjunction with Parts I and II to illustrate the actual mechanism of the
decisionmaking process.
182. All of the comparisons made in the example Part III were based on
a reference sediment or reference water representative of pristine background
areas of Puget Sound in accordance with the goal for returning Commencement Bay
back to a cleaner environment. Consequently, more dredged material will be
found to exceed reference values by substantially wider margins and thus
restrictions will be required in more cases than if a less pristine reference
site were chosen.
183. A summary of the decisions reached using the tentative
Commencement Bay area LADs for disposal of sediments A, B, and C in aquatic,
upland, and nearshore environments is presented in Table 22. The tentative
decisions of Commencement Bay area authorities were to administratively
establish numeral guidance for interpreting bioaccumulation and each of the
LADs points in Figures 6-9, Al and A2, and B1-B8. These decisions resulted in
the need for restrictions on disposal of sediment A in each of the three dis-
posal environments; sediment B required restrictions in both upland and near-
shore disposal environments while only needing restrictions for the benthic
portion of the aquatic disposal site (no restrictions were required for the
water column portion); and sediment C required restrictions in the upland
disposal environment for animal uptake and in the nearshore disposal environ-
ment for effluent water, leachate quality, and animal uptake, while only need-
ing restrictions for the benthic portion of the aquatic disposal site.
Hypothetical data were used for illustrating the actual implementation of the
decisionmaking framework and should not be construed as factual. Actual data
and test results for Commencement Bay sediments will no doubt give different
conclusions than presented in this report.
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PART V: RECOMMENDATIONS
184. This document has been a continuing evaluation since initiation and
has been prepared on the basis of technically sound conceptual approaches.
It requires a continuing thorough technical review, but it is suitable for
initial use. Many of the issues evaluated require further consideration and
possible refinement as the document is developed into a more final form.
Examples of some of these issues are listed below:
• The appropriateness of developing additional quantitative
guidance for acceptable contaminant concentrations in animal
tissues from human health and biological impact perspectives
should be examined. Initial bioaccumulation screening techni-
ques based on partitioning theory should be incorporated where
appropriate, and the potential for biomagnification should be
considered in relation to both human health and environmental
impacts. Evaluation of potential human health impacts based on
FDA limits could be supplemented by a ranking of contaminants
by their importance in mammalian toxicology, perhaps based on
health tolerances and/or cancer risks. Assessment of potential
biological impacts could be improved by tabulation of tissue
contaminant concentrations in organisms from so-called "clean"
sites worldwide and summarization of literature on biological
effects associated with specific levels of tissue contamination.
• The framework at present considers only chemical contaminants
impacts. The same conceptual approach could be expanded to
provide guidance on evaluation of the potential impacts of
traditional parameters such as chemical oxygen demand (COD),
etc.
• Practical utility of the framework in interpreting all chemical
evaluations is dependent upon, among other things, identifica-
tion of a manageable number of contaminants of concern for each
project. At present, identification of the appropriate con-
taminants remains largely a subjective matter. Additional
guidance is needed for identifying appropriate contaminants of
concern for a given project, perhaps considering such things as
contaminants present, concentrations, toxicological importance,
and bioavailability and mobility in the system in question.
• Contaminants of concern must be analyzed with sufficient
sensitivity to provide quantitation at concentrations of
regulatory concern. The merits of specifying detection limits
on the basis of (a) criteria or standards, (b) ability to
quantitate clean reference materials, (c) technical attain-
ability, and (d) routine availability should be considered and
discussed. Different detection limits may be appropriate for
different purposes or for different matrices (i.e., water,
sediment, tissue) with the same contaminant.
• Findings of ongoing research need to be incorporated into the
decisionmaking framework. This would involve both quantitative
91
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test results and new insights regarding interpretation and
evaluation of data. Programs such as the CE Long-term Effects
of Dredging Operations (LEDO) Research Program, CE/EPA Field
Verification Program (FVP), EPA research on Exposure and Bio-
logical Effects of In-Place Pollutants, other EPA research, and
programs of other Federal and State agencies, particularly in
the Puget Sound area, will provide useful input to the decision-
making framework. The process of incorporation of findings of
ongoing research must continue throughout the useful life of
the document to keep it current.
• Guidance on evaluating potential ground-water leachate should
be reviewed and revised, if necessary, to ensure technical and
regulatory compatability with the proposed new EPA ground-water
classification system when it is finalized.
• The decisionmaking framework is dependent upon local authority
decisions (LADs) whenever scientific understanding is insuf-
ficient to justify decisions on a technical basis alone. For
this reason, quantitative guidance on reaching the LADs is dif-
ficult to provide and potentially controversial. Yet their
importance necessitates the most complete and objective guidance
possible. The guidance for making LADs needs to be made as
complete, objective, and quantitative as possible.
• Performance of all the tests required even for site-
acceptability testing could exceed the cost of dredging fo.r
some small projects. Yet these projects could involve highly
contaminated sediments. An effective means of adequately
assessing potential environmental impacts of small projects
without imposing prohibitive economic burdens needs to be
identified.
• The concept of tiered testing needs to be incorporated in the
framework wherever possible. In this approach relatively
simple procedures are used as screening tests, perhaps
eliminating the need for more extensive testing. This could be
part of a useful approach for small projects.
• In order to document that the decisionmaking framework is, in
fact, providing the degree of environmental protection expected
of it, it is necessary to monitor the actual effects of dis-
charge decisions reached by using the framework. These monitor-
ing requirements and the interpretive guidance for evaluating
the results will be generally similar to the testing and evalua-
tion guidance in the decisionmaking framework. Monitoring and
evaluative guidance needs to be clearly described in an orderly
fashion.
• Although both aquatic and upland disposal operations can be
designed and conducted so as to minimize loss of suspended
particulates, it is inevitable that some particulate matter
will leave the site. These particulates might conceptually be
of concern if they were transported to and accumulated in
appropriate areas such as beaches, spawning beds, etc.; if they
concentrated contaminants to unacceptable levels in a deposi-
tional area away from the disposal site; or if there was a
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potential for particle-associated contaminants to impact the
water column as they were being dispersed. Attention should be
given to evaluation of the potential for impact by these
routes.
• The decisionmaking framework, should be modified in the future
as appropriate based on scientific and administrative experience
with using it. The document has received technical review, and
additional technical review at successive stages of its develop-
ment is necessary. In addition, it should be used, perhaps in
a dry-run sense, to evaluate several projects in order to
identify problem areas and indicate potential improvements.
The decisionmaking framework is intended to provide a useful
first step with the full knowledge of the need for further
technical and administrative refinement prior to actual
implementation.
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Material Disposal," Technical Report D-83-2, US Army Engineer Waterways Exper-
iment Station, Vicksburg, Miss.
Simmers, J. W., Rhett, R. G., and Lee, C. R. 1983. "Application of a Terres-
trial Animal Bioassay for Determining Toxic Metal Uptake from Dredged Mate-
rial," Proceedings, International Conference on Heavy Metals in the Environ
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Stewart, K. M. 1984. "Effects of Dredging and Dredged Material Disposal on
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Material Disposal: Proceedings of the Conference Dredging '84, R. L.
Montgomery and J. W. Leach, eds., American Society of Civil Engineers,
New York, pp 579-588.
Sullivan, B. K., and Hancock, D. 1977. "Zooplankton and Dredging: Research
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Sweeney, R. 1977. "Aquatic Disposal Field Investigations, Ashtabula River
Disposal Site, Ohio: Evaluative Summary," Technical Report D-77-42, US Army
Engineer Waterways Experiment Station, Vicksburg, Miss.
Tatem, H. L., and Johnson, J. F. 1977. "Aquatic Disposal Field Investiga-
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98
-------
Wright, T. D. 1977. "Aquatic Disposal Field Investigations, Galveston, Texas,
Offshore Disposal Site: Evaluative Summary," Technical Report D-77-20, US Army
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99
-------
Table 1
Relative Time and Cost Estimates for Conducting Test Protocols
Test Protocol
Dissolved chemical analysis
and mixing
Water column bioassay and
mixing
Sediment comparison
Benthic bioassay and
bioaccumulationtt
Effluent quality
Runoff
Leachate^
Plant uptake^
Animal uptake§
Time
months
2
3
2
5
2
6
12
4
4
Cost/
Test Run*
dollars
100
1,000-5,000
100
1,000-5,000
80
4,000
25,000
5,000
4,000
Number
of Test
Samples
Analyzed
6
16
8
16
6
15
50
12
12
Cost of
Chemical
Analysis**
dollars
6,000- 9,000
8,000-12,000
16,000-24,000
6,000- 9,000
15,000-22,500
50,000-75,000
12,000-18,000
12,000-18,000
Total Cost
dollars
6,100- 9,100
1,000- 5,000
8,100- 12,100
17,000- 29,000
6,080- 9,080
19,000- 26,500
75,000-100,000
17,000- 23,000
16,000- 22,000
* One sediment sample.
** Estimated cost for PCBs , pesticides, 10 metals, and suspended solids per analyzed sample ranged
from $1,000 to $1,500.
t Dots not include cout of equipment or facilities or sample collection and transport to lab,
1"t four. ypv:,.:ifcs v-?rc u^e-i.
ar-^ currently under
K. vriri
f-
j- !' iUaaC b-lo^ir.fay i;r 45 -Jay evoosiire.
§ Earthworm bioassay of 28-day exposure.
-------
Table 2
Detection Limits for a Preliminary List of Contaminants
of Potential Concern in Commencement Bay*
Sediment Plant Animal
Contaminants
Metals
Ag
As
Be
Cd
Cr
Cu
Hg
Ni
Pb
Sb
Se
II
Zn
Volatiles
Benzene**
Bromoform
Carbon tetrachloride
Chloroform
Chloroethane
Chlorodibromome thane
Dichloromethane
Dichlorobromome thane
Ethylbenzene**
Formaldehydet
Tetrachloroe thane**
1,1, 1-Trichloroethylene
Toluene
1 , 1-Dichloroethane
1 , 1-Dichloroethylenet
1 , 2-trans-Dichloroethylenet
Xylene**
Base/Neutrals (except PCBs)
Haloginated compounds
Hexachloroe thane
1 , 2-Dichlorobenzene
1 , 3-Dichlorobenzene
* Priority pollutants and other
ment Bay sediments, waters, or
** Reported in waters but not in
t Reported only in point sources
tt NA - Not applicable.
Water
mg/kg mg/kg mg/kg yg/&
0.1 0.
L 0.1
0.1 0.05 0.1
0.5 0.5 0.5
0.01 0.01 0.01
0.1 0.05 0.1
0.1 0.1
0.1 O.J
L 0.1
L 0.1
0.3 0.05 0.3
0.1 0.1 0.1
0.5 0.5 0.5
0.2 0.05 0.2
0.1 0.]
0.1 0.]
L 0.1
L 0.1
0.050 NAtt NA
'
1
0.2 0.2 0.2
0.2 0.2 0.2
0.2 0.2 0.2
(Continued)
significant substances detected in
point sources.
0.6
1
5
0.1
1
1
0.2
3
0.1
5
2
1
1
10
10
10
10
Commence-
sediments (to date).
,
(Sheet 1 of 3)
-------
Table 2 (Continued)
Contaminants
Base/Neutrals
Haloginated compounds (Continued)
1,4-Dichlorobenzene
1,2,4-Trichlorobenzene
2-Chloronaphthalene
Hexachlorobenzene
Hexachlorobutadiene
Misc. chlorinated butadienes**
Bis(2-chloroethyoxy) ether
Bis(2-chloroethyoxy) methane
Low molecular weight aromatics
Azobenzene
Naphthalene
2-methylnaphthalene**
1-methylnaphthalene**
2,6-dimethylnaphthalene**
1,3-dimethylnaphthalene**
2,3-dimethylnaphthalene**
2,3,6-trimethylnaphthalene**
2,3,5-trimethylnaphthalene**
Acenaphthene
Acenaphthalene
Fluorene
Biphenyl**
Anthracene/phenanthrene
1-methylphenanthrene**
2-methylphenanthrene**
High molecular weight aromatics
Fluoranthene
Pyrene
1-methylpyrene**
Benzo(a)anthracene
Chrysene/triphenylene
Dibenzo(a,h)anthracene
Benzofluoranthenes
Benzo(e)pyrene**
Benzo(a)pyrene
Indeno(l,2,3-cd)pyrene
Benzo(g,h,i)perylene
Phthalate esters
Diethylphthalate
Bis(2-ethylhexyl)phthalate
Sediment
ing/kg
0.2
0.2
0.2
0.
0.
0.
0.2
0.
0.
0.2
0.2
Plant
mg/kg
0.2
0.2
0.2
0.5
0.2
0.2
0.2
0.5
0.5
0.2
0.2
Animal
mg/kg
0.2
0.2
0.2
0.
0.
0.
0.
0.
0.
0.2
0.2
10
10
10
25
10
10
10
25
25
10
10
(Continued)
** Reported in waters but not in sediments (to date).
(Sheet 2 of 3)
-------
Table 2 (Concluded)
Contaminants
Base/Neutrals
Phthalate esters (Continued)
Butylbenzylphthalate
Di-n-butylphthalate
Di-me-phthalate
Di-n-octylphthalate
Acid Extractables
Cresol**
Phenol
2-chlorophenol
2,4-dichlorophenolt
2,4,6-trichlorophenol
Pentachlorophenol
P-chloro-m-cresol
4-nitrophenol
Pesticides and PCBs
A-chlordane
Aldrin
a-Hexachlorocyclohexane (HCH)'
6-HCH
Y-HCH (lindane)
4-4'-ODD
4,4'-DDE
4,4'-DDT
PCB-1242
PCB-1248
PCB-1254
PCB-1260
Miscellaneous substances
Manganese (Mn)'
Molybdenum (Mo)'
A-endosulfant
Cyanidet
Nitrosodiphenylamine
Sediment
mg/kg
0.2
0.5
1
0.2
2
2
2
4
0.1
0.1
0.2
1
0.2
Plant
mg/kg
0.2
0.5
0.001
0.0002
0.002
0.002
0.002
0.004
0.1
0.0001
0.0002
1.0
0.2
Animal
mg/kg
0.2
0.5
0.001
0.0002
0.002
0.002
0.002
0.004
0.1
0.0001
0.0002
1.0
0.2
10
25
0.001
0.010
0.01
0.01
0.01
0.02
0.001
0.001
0.004
1
0.010
**
t
tt
Reported only in point sources.
Reported in waters but not in sediments (to date).
Hexachlorocyclohexanc (HCH) is sometimes referred to elsewhere as BHC
(benzene hexachloride), but this is a misnomer and is not used here.
(Sheet 3 of 3)
-------
Table 3
Hypothetical Example of Concentrations of Dissolved Contaminants in
Standard
Contaminants
of Concern
As
Cd
Cu
Pb
Hg
Zn
Base/neutrals
Naphthalene
Fluorene
Phenanthrene
Fluoranthene
Pyrene
Benzo (a) pyrene
Hexachlorobutadiene
Hexachlorobenzene
Acid extractable
Pentachlorophenol
Pesticides
PCB (total)
Elutriates of
Acute
Criterion-
Saltwater
— *
59
23
—
3.7
170
—
—
—
—
—
—
—
—
—
0.030
Three Puget Sound Sediments
Reference
Site Sediment
Water A B
10.0 35 27
0.2 1.2 0.9
1.1 10 2.3
2.2 8 9.1
0.01 0.03 0.02
12.8 32 16.7
<1 32
<1 32
<1 2 1
<1 1 <1
<1 <1 <1
<1 <1 <1
<1 <1 <1
<1 <1 <1
<1 <1 <1
0.005 0.04 0.03
C
5
0.3
1.2
3.1
0.01
13
<1
<1
<1
<1
<1
<1
<1
<1
<1
0.02
Note: Values are in ug/Jl.
* — denotes criterion not established.
-------
Table 4
Hypothetical Example of Toxicity of Elutriates of
Three Puget Sound Sediments
Sediment
Species
Surf perch
(Cymatogaster aggregata
juveniles)
Mysid shrimp
(Neomysis americanus)
Dungeness crab
(Cancer magister
larvae)
Treatment
Control
Reference site water
10% elutriate
50% elutriate
100% elutriate
Control
Reference site water
10% elutriate
50% elutriate
100% elutriate
Control
Reference site water
10% elutriate
50% elutriate
100% elutriate
A
0
0
0
3
10
0
0
10
55*
72
3
7
7
42
81**
B
0
0
3
3
7
0
3
3
7
12
0
0
0
18
42
C
0
0
0
0
0
0
0
0
3
0
0
3
3
7
15
Note: Each treatment consisted of three replicates of 10 animals each.
Values are mean percent mortality after 96 hr.
* 96-hr LC50 is 45 percent elutriate.
** 96-hr LC50 is 58 percent elutriate.
Table 5
Hypothetical Example of Toxicity of Elutriates of Three Puget Sound
Sediments
to Oyster Larvae
(Crassostrea gigas)
Treatment
Control
Reference site water
10% elutriate
50% elutriate
100% elutriate
A
0.5
4.7
5.3
32.9*
69.6
Sediment
B
2.9
5.8
2.4
21.6
39.0
C
2.0
3.2
2.1
7.2
21.3
Note: Values are mean percent abnormal larvae from two replicates per
treatment after 48 hr.
* 48-hr EC50 for abnormality is 65 percent elutriate.
-------
Table 6
Hypothetical Example of Toxicity of Deposits of Four Puget Sound
Sediments to Araphipods Grandifoxus grandis
Treatment
Control
Exposed
Reference
0
6
Sediment
ABC
000
96 32 14
Note: Each treatment consisted of five replicates of 10 animals each.
Values are mean percent mortality after 96 hr.
Table 7
Hypothetical Example of Toxicity of Deposits of Four Puget Sound
Sediments
Species
Pandalus borealis
Maaoma balthica
Neanthes arenaaeodentata
Farophrys vetulus
(juvenile)
to Four Benthic
Treatment
Control
Exposed
Control
Exposed
Control
Exposed
Control
Exposed
or Epibenthic
Reference
0
0
0
0
0
0
0
1
Species
Sediment
A
0
15
0
2
1
18
0
2
B
0
5
0
3
2
6
0
1
C
1
0
0
0
0
0
0
0
Note: Each treatment consisted of five replicates of 20 animals each.
Values are mean percent mortality after 10 days.
-------
Table 8
Clam Macoma balthiaa Exposed to Deposits
of Four Fuget Sound
Sediments for 30 Days
Contaminants
of Concern
As
Cd
Cu
Pb
Hg
Zn
Base/neutrals
Naphthalene
Fluorene
Phenanthrene
Fluoranthene
Pyrene
Benzo(a)pyrene
Hexachlorobutadiene
Hexachlorobenzene
Acid extractable
Pentachlorophenol
Pesticides
PCB (total)
FDA
Level*
1.0
1.0
70
2.5
0.5
150
— **
—
—
—
—
—
—
—
—
2.0
Reference
0.230
0.062
1.11
0.683
0.478
16.67
0.01
0.0003
0.0002
0.0005
0.001
0.0001
0.004
0.008
0.001
0.004
Sediment
A
23.37
2.38
7.77
12.99
7.10
26.26
0.007
0.011
0.010
0.010
0.010
0.013
0.001
0.046 .
0.006
0.010
B
8.87
1.68
3.11
1.37
0.79
18.71
0.024
0.014
0.014
0.015
0.014
0.009
0.038
0.070
0.008
0.146
C
0.317
0.21
0.95
0.748
0.281
17.31
0.014
0.083
0.082
0.080
0.088
0.005
0.025
0.024
0.014
0.150
Note: Data are in ug/g on a whole body, wet weight basis.
* From Table Cl.
** — denotes no value established.
-------
Table 9
Hypothetical Example of Contaminant Concentrations in Tissues of the
Shrimp Pandalus
borealis
Exposed to Deposits
of Four
Puget Sound
Sediments for 30 Days
Contaminants
of Concern
As
Cd
Cu
Pb
Hg
Zn
Base/neutrals
Naphthalene
Fluorene
Phenanthrene
Fluoranthene
Pyrene
Benzo (a) pyrene
Hexachlorobutadiene
Hexachlorobenzene
Acid extractable
Pentachlorophenol
Pesticides
PCB (total)
FDA
Level*
1.0
— **
10
1.5
0.5
150
—
—
—
—
—
—
—
—
—
2.0
Sediment
Reference
0.71
0.350
8.76
0.798
0.023
10.09
0.003
0.001
0.0007
0.001
0.0001
0.0002
0.008
0.16
0.003
0.008
A
8.62
2.38
23.5
6.42
2.47
9.41
0.013
0.021
0.020
0.020
0.025
0.025
0.002
0.088
0.008
0.020
B
1.63
0.165
4.76
0.619
0.038
9.99
0.046
0.027
0.026
0.029
0.021
0.020
0.073
0.132
0.015
0.277
C
0.27
0.017
2.67
0.581
0.035
11.27
0.088
0.047
0.050
0.057
0.040
0.041
0.048
0.046
0.026
0.285
Note: Data are in yg/g on a whole body, wet weight basis.
* From Table Cl.
** — denotes no value established.
-------
Table 10
Hypothetical Example of Contaminant Concentrations in Tissues of the
Polychaete Worm Neanthes arenaoeodentata Exposed to Deposits of
Four
Contaminants
of Concern
As
Cd
Cu
Pb
Hg
Zn
Base/neutrals
Naphthalene
Fluorene
Phenanthrene
Fluoranthene
Pyrene
Benzo(a)pyrene
Hexachlorobutadiene
Hexachlorobenzene
Acid extractable
Pentachlorophenol
Pesticides
PCB (total)
Puget Sound
FDA
Level*
1.0
0.2
10
1.5
0.5
150
— **
—
—
—
—-
—
—
—
—
2.0
Sediments for
Reference
0.373
0.45
7.82
0.62
0.12
6.58
0.006
0.0005
0.0005
0.001
0.001
0.0002
0.006
0.010
0.002
0.005
30 Days
Sediment
A
15.84
6.42
25.37
13.27
2.61
18.63
0.009
0.014
0.013
0.012
0.013
0.015
0.001
0.058
0.002
0.013
B
0.99
0.78
5.65
0.97
0.387
5.62
0.030
0.018
0.017
0.018
0.020
0.030
0.048
0.097
0.015
0.182
C
0.208
0.18
9.07
0.96
0.019
9.94
0.017
0.031
0.030
0.031
0.37
0.022
0.031
0.030
0.058
0.018
Note: Data are in ug/g on a whole body, wet weight basis.
* From Table Cl. See paragraph 26 for rationale for using these values
with a nonfood type of organism.
** — denotes no value established.
-------
Table 11
Hypothetical Example ot Contaminant Concentrations in Tissues of the
Juvenile English Sole Parophrys vetulus Exposed to Deposits of
Four Puget Sound
Contaminants FDA
of Concern Level*
As 1.0
Cd 0.2
Cu 10
Pb 1.5
Hg 1.0
Zn 150
Base/neutrals
Naphthalene — **
Fluorene
Phenanthrene
Fluoranthene
Pyrene
Benzo (a) pyrene
Hexachlorobutadiene
Hexachlorobenzene —
Acid extractable
Pentachlorophenol
Pesticides
PCB (total) 2.0
Sediments
Reference
0.12
0.026
1.89
0.086
0.008
6.55
0.003
0.001
0.0007
0.001
0.0005
0.001
0.011
0.021
0.001
0.010
for 30 Days
Sediment
A
14.47
7.81
8.76
18.16
2.1
12.54
0.018
0.027
0.028
0.025
0.030
0.031
0.003
0.116
0.003
0.26
B
3.53
1.98
1.68
1.83
0.010
5.26
0.061
0.036
0.038
0.037
0.020
0.020
0.096
0.174
0.010
0.364
C
0.12
0.07
5.93
1.15
0.003
7.02
0.035
0.062
0.060
0.050
0.060
0.062
0.063
0.060
0.002
0.375
Note: Data are in ug/g on a whole body, wet weight basis.
* From Table Cl.
** — denotes no value established.
-------
Table 12
Effluents
Contaminants
of Concern
As
Cd
Cu
Pb
Hg
Zn
Base/neutrals
Naphthalene
Fluorene
of Confined
Three Puget
Acute
Criterion-
Saltwater
_ — *
59
23
—
3.7
170
—
—
Disposal Areas
Sound Sediments
Reference
Site Water
3.2
1.6
2.1
1.5
<0.1
10
<1
<1
Containing
Sediment
A
525
180
1,800
380
1.4
2,000
12
11
B C
70 25
80 1.5
120 28
12 6
0.2 <0.1
130 42
12 <1
<1 <1
Phenanthrene
Fluoranthene
Pyrene
Benzo(a)pyrene
Hexachlorobutadiene
Hexachlorobenzene
Acid extractable
Pentachlorophenol
Pesticides
PCB (total)
11
11
11
10
0.030
0.01
0.05
12
0.87 0.48
Note: Values are in
* — denotes criterion not established.
-------
Table 13
Hypothetical Example of Concentrations of Dissolved Contaminants in
Surface Water Runoff of Confined Disposal Areas Containing
Three Puget SOUP-' Sediments
Contaminants
of Concern
As
Cd
Cu
Pb
Hg
Zn
Acute
Criterion-
Saltwater
A
59
23
—
3.7
170
Reference
Site Water
3.2
1.6
2.1
1.5
<0.1
10
A
40
110
300
108
10
250
Sediment
B
5
4
50
20
1
100
C
2
1
8
5
<0.1
60
Base/neutrals
Naphthalene
Fluorene
Phenanthrene
Fluoranthene
Pyrene
Benzo(a)pyrene
Hexachlorobutadiene
Hexachlorobenzene
Acid extractable
Pentachlorophenol
Pesticides
PCB (total)
a
0.030
0.01
0.05
0.5
cO.Ol'
Note: Soil surface was dried to typical field moisture content prior to
tests. Values are in pg/£.
* — denotes criterion not established.
-------
Table 14
Hypothetical Example of Total or Bulk Contaminant
Concentrations in Four
Puget Sound Sediments
Contaminants
of Concern
As
Cd
Cu
Pb
Hg
Zn
Base/neutrals
Naphthalene
Fluorene
Phenanthrene
Fluoranthene
Pyrene
Benzo(a)pyrene
Hexachlorobutadiene
Hexachlorobenzene
Acid extractable
Pentachlorophenol
Pesticides
PCB (total)
Sand , percent
Silt, percent
Clay, percent
TOC, percent
Sediment
Reference
5.5
0..24
54.0
10.0
0.10
50.8
0.029
0.007
0.070
0.030
0.065
0.060
0.029
0.065
0.030
0.025
30.0
40.0
30.0
2.5
A
9,700
184
11,400
6,250
52
3,320
0.540
0.835
0.760
0.870
1.350
1.050
0.025
1.280
0.100
0.260
66.7
25.2
7.8
8.8
B
90.0
3.6
239.0
181.0
0.50
242.0
1.012
0.600
1.210
12.250
8.800
6.190
0.480
1.050
0.100
2.000
20.2
54.7
25.1
4.4
C
14.0
1.6
115.0
81.0
0.18
107.0
0.350
0.625
0.600
1.500
0.150
0.190
0.180
0.220
0.350
1.245
38.7
42.3
19.0
2.9
Note: Values in mg/kg dry weight, except as otherwise indicated.
-------
Table 15
Hypothetical Example of Concentrations of Dissolved Contaminants in Leachate of
Contaminants
of Concern
As
Cd
Cu
Pb
Hg
Zn
Base/neutrals
Naphthalene
Fluorene
Phenanthrene
Fluoranthene
Pyrene
Benzo (a) pyrene
Hexachlorobutadiehe
Hexachlorobenzene
Acid extractable
Pentachlorophenol
Pesticides
PCB (total)
Confined Disposal Areas Containing Three Puget Sound Sediments
Chronic Criterion- Drinking Water Reference
Saltwater* Standard** Water A
— t 50 2 120
4.5 10 1 500
4.0 1,000 17 2,000
50 1.0 500
0.025 2 0.1 7.0
58 5,000 10 1,500
II II <} <}
<1
-------
Table 16
Hypothetical Example of DTPA-Extractable Metals from Four Puget Sound Sediments
Sediment
Contaminants
of Concern
Cd
Cu
Pb
Hg
Zn
Reference
Saturated
0.0024
<0.025
0.001
<0.001
0.05
Dried
0.0030
0.67
0.0012
0.001
5.8
A
Saturated
0.001
0.05
0.91
0.001
0.10
Dried
51.0
71.2
388
1.20
954
B
Saturated
<0.0005
0.04
9.71
0.0010
0.31
Dried
1.51
39.6
73.4
0.0019
126
C
Saturated
0.0020
<0.025
0.72
<0.001
0.24
Dried
0.012
2.41
2.01
0.0014
11.2
-------
Table 17
Hypothetical Example of Plant Growth, Tissue Content, and Total Uptake of Contaminants for
Yellow Nutsedge
, Ciiperus esculentus, Grown in Four Puget Sound Sediments
Sediment
Contaminants Effect
Reference
of Concern Level* Yield Content
Growth
As
Cd 8
Cu 20
Pb
Hg
Zn 200
Base/neutrals
Naphthalene —
Fluorene —
Phenanthrene —
Fluoranthene —
Pyrene —
Benzo(a)pyrene —
Hexachlorobutadiene —
Hexachlorobenzene —
Acid extractable
Pentachlorophenol —
Pesticides
PCB (total)
46
0.041
1.05
2.54
1.58
0.010
81.0
<0.08
<0.08
<0.08
<0.08
<0.08
<0.08
<0.08
<0.08
<0.08
<0.002
A
B
Uptake Yield Content Uptake Yield Content
14
2
48
117
73
0.5
3,726
<4
<4
<4
<4
<4
<4
<4
<4
<4
<0.09
43
1
21
9
4
0
290
<0
<0
<0
<0
<0
<0
<0
<0
<0
<0
.45 20
.05 295
.51 133
.10 57
.90 13
4,060
.08 <1
.08 <1
.08 <1
.08 <1
.08 <1
.08 <1
.08 <1
.08 <1
.08 <1
.002 <0.03
0
5
4
1
0
90
<0
<0
<0
<0
<0
<0
<0
<0
<0
<0
.38
.32
.41
.80
.016
.08
.08
.08
.08
.08
.08
.08
.08
.08
.002
c
Uptake Yield Content
Uptake
67
16
229
203
77
0.7
3,870
<3
<3
<3
<3
<3
<3
<3
<3
<3
<0.09
0
0
1
1
0
54
<0
<0
<0
<0
<0
<0
<0
<0
<0
<0
.030
.71
.70
.05
.008
.1
.08
.08
.08
.08
.08
.08
.08
.08
.08
.002
2
47
113
70
0.5
3,625
<5
<5
<5
<5
<5
<5
<5
<5
*5
<0.13
Note: Soil was maintained at typical field moisture content during plant growth.
yield, Mg/g for content, and ug/pot for uptake.
* Table C5.
Values are on a dry weight basis in g/pot for
-------
Table 18
Hypothetical Example of Toxicity of
Treatment
Control
Exposed
Four Puget Sound Sediments to
Earthworms, Eisenia foetida
Sediment
Reference A B
1 0 1
0 98 1
C
0
0
Note: Soil was maintained at typical field moisture
content during the test. Each treatment con-
sisted of five replicates of 20 animals each.
Values are mean percent mortality after 30 days.
-------
Table 19
Hypothetical Example of Animal Growth, Tissue Content, and Total Uptake of Contaminants for
Contaminants
of Concern
Growth
As
Cd
Cu
Pb
Hg
Zn
Base/neutrals
Naphthalene
Fluorene
Phenanthrene
Fluoranthene
Pyrene
Benzo (a) pyrene
Hexachlorobutadiene
Hexachlorobenzene
Acid extractable
Pentachlorophenol
Pesticides
PCB (total)
the Earthworm
Reference
Yield Content
15.0
3.36
4.05
160
2.9
0.012
125
0.005
0.001
0.015
0.002
0.055
0.050
0.008
0.05
0.06
0.05
Eicenia foetida Exposed to
A
Uptake Yield Content
1.8
50.4
60.7
2,400
43.5
1.8
1,875
0.075
0.015
0.225
0.03
0.82
0.75
0.12
0.75
0.90
0.750
Four Puget Sound Sediments for
Sediment
B
Uptake Yield Content
13.5
8.91 1
7.02
250 3
200 2
0.008
190 2
0.85
0.54
0.75
2.55
1.05
5.25
0.31
0.65
0.09
0.32
30 Days
Uptake
,203
94.8
,375
,700
0.108
,565
11.5
7.3
10.1
34.4
14.2
70.9
4.2
8.8
1.22
4.3
C
Yield Content
16.5
1.87
8.17
170
105
0.20
165
0.25
0.50
0.55
0.45
0.09
0.050
0.160
0.21
0.08
0.35
Uptake
30.8
134.1
2.805
1,732
3.3
2,722
4.1
8.2
9.1
7.4
1.5
0.8
2.6
3.5
1.3
5.8
Note: Soil was maintained at typical field moisture content during the test.
yield, ug/g on a whole body basis for content, and ug/pot for uptake.
Values are on a dry weight basis in g/pot for
-------
Table 20
Hypothetical Example of Concentrations of Dissolved Contaminants in the Saturated Zone
Leachate of a Nearshore Disposal Area Containing
Contaminants Chronic Criterion- Drinking Water
of Concern Saltwater* Standard**
As — t 50
Cd 4.5 10
Cu 4.0 1,000
Pb — 50
Hg 0.025 2
Zn 58 5,000
Base /neutrals
Naphthalene — —
Fluorene — —
Phenanthrene — —
Fluoranthene — —
Pyrene —
Benzo(a)pyrene — —
Hexachlorobutadiene — —
Hexachlorobenzene — —
Acid extractable
Pentachlorophenol — —
Pesticides
PCB (total) 0.03
Three Puget
Reference
Water
2
1
17
1.0
0.1
10
-------
Table 21
Hypothetical Example of Toxicity of Effluents (Modified
Elutriates)
Species
Surf perch
(Cymatogaster aggregata
juveniles)
Mysid shrimp
(Ueomysis americanus)
Dungeness crab
(Cancer magister
larvae)
Oyster
(Crassostrea gigas
larvae)
of Three
Treatment
% Modified
Elutriate
0
10
50
100
0
10
50
100
i
0
10
50
100
0
10
50
100
Puget Sound Sediments
Reference
Site
Water
0
0
1
0
0
1
1
3
5
0
4
2
2.1
2.8
4.4
6.4
A
0
0
13
20
0
20
65*
83
3
7
59**
88
1.6
8.3
58. 4*
91.2
Sediment
B
0
3
6
10
0
9
17
22
0
4
28
42
2.9
6.5
39.9
68.2^
C
0
0
1
0
0
0
3
0
0
3
7
6
1.8
2.1
6.3
4.6
Note: Oyster data are mean percent abnormal larvae from two replicates per
treatment after 48 hr. For other species each treatment consisted of
three replicates of 10 animals each. Values are mean percent mortal-
ity after 96 hr, or mean percent abnormality after 48 hr for oysters.
* 96-hr LC50 is 39 percent modified elutriate.
** 96-hr LC50 is 44 percent modified elutriate.
t 48-hr EC50 for abnormality is 45 percent modified elutriate.
tt 48-hr EC50 for abnormality is 55 percent modified elutriate.
-------
Table 22
Summary of Tentative Commencement Bay Area Authority Decisions Made
for Three Sediments and Three Potential Disposal Environments
Potential Using Hypothetical Test Results
Potential Disposal
Sediment Environment
A Aquatic
Upland
Nearshore
Aquatic
Upland
Nearshore
Aquatic
Upland
Nearshore
Component
Water column
Benthic
Effluent
Runoff
Leachate
Plant uptake
Animal uptake
Human exposure
Effluent
Runoff
Leachate
Plant uptake
Animal uptake
Human exposure
Water column
Benthic
Effluent
Runoff
Leachate
Plant uptake
Animal uptake
Human exposure
Effluent
Runoff
Leachate
Plant uptake
Animal uptake
Human exposure
Water column
Benthic
Effluent
Runoff
Leachate
Plant uptake
Animal uptake
Human exposure
Effluent
Runoff
Leachate
Plant uptake
Animal uptake
Human exposure
Tentative
Decisions
Restrictions
Restrictions
Restrictions
Restrictions
Restrictions
Restrictions
Restrictions
Restrictions
Restrictions
Restrictions
Restrictions
Restrictions
Restrictions
Restrictions
Restrictions
Restrictions
No restrictions
No restrictions
Restrictions
Restrictions
Restrictions
No restrictions
No restrictions
No restrictions
Restrictions
Restrictions
Restrictions
No restrictions
No restrictions
Restrictions
No restrictions
No restrictions
No restrictions
No restrictions
Restrictions
No restrictions
Restrictions
No restrictions
Restrictions
No restrictions
Restrictions
No restrictions
-------
APPENDIX A: DECIS10NMAKING FRAMEWORK FOR AQUATIC DISPOSAL
CONTENTS
Water Column Evaluation
.Decision from chemical evaluations A5
Local authority decision: restrictions/no restrictions/
consider mixing A6
Decision for further evaluation: consider mixing A9
Local authority decision: bioassays A10
Decisions from biological evaluations All
Local authority decision: restrictions/no restrictions/
consider mixing A12
Decision for further evaluation: consider mixing A14
Benthic Evaluation A15
Decisions from chemistry and toxicity evaluations A17
Decisions from bioaccumulation evaluations A18
Local authority decision: need for restriction A19
* NOTE: Alphanumeric identification of pages, paragraphs, and figures was
used in the appendices to distinguish them from the simple numbers
used as identification of main-text pages, paragraphs, figures, and
tables. Thus references to simple numbers in the appendices refer
to similarly numbered items in the main text.
Al
-------
A2
-------
APPENDIX A: DECISIONMAK1NG FRAMEWORK FOR AQUATIC DISPOSAL
Al. Concerns about contaminant impacts from aquatic disposal have cen-
tered on short-term impacts in the water column during and immediately after
disposal and on long-term impacts of the deposited sedimen1 on the benthic
environment after disposal. The tests appropriate for determining the pos-
sibility of these impacts occurring are different and are shown separately in
Figure Al.
Water Column Evaluation
A2. The possibility of water column impacts of contaminants released
by dredged material disposal has been recognized and intensively studied for
years. These studies have included dredged material containing high concen-
trations of a wide variety of metals and organic contaminants discharged from
hoppers, barges, and pipelines, and have included both laboratory and field
investigations. The overwhelming preponderance of evidence from these studies
demonstrates no unacceptable adverse impacts on the water column from con-
taminants in dredged material (Arimato and Feng 1983; Brannon 1978; Burks and
Engler 1978; DeLoach and Waring 1984; Hirsch, et al. 1978; Stewart 1984;
Sullivan and Hancock 1977; Sweeney 1977; Tatem and Johnson 1977; Tramontane
and Bohlen, 1984; Wright 1977 and 1984*). The most likely situations in which
aquatic disposal may produce contaminant-associated impacts in the water
column involve prolonged high volume discharges into small, poorly mixed water
bodies or embayments. These make very poor disposal sites for reasons
unrelated to contaminants and are very seldom proposed for such use.
A3. Studies such as those cited above do not prove that water column
impacts will not occur with aquatic disposal. However, they do indicate that
such impacts are sufficiently unlikely that the local authority must decide
whether it is appropriate to divert funds for testing for potential water col-
umn impacts in association with disposal in aquatic sites where rapid disper-
sion and dilution will occur. In many cases it will be possible to assess the
potential for water column impacts on the basis of previous water column test-
ing and characteristics of the disposal site without conducting additional
sediment-specific testing.
* References are listed at the end of the main text.
A3
-------
>
*>
EVALUATION
-TOXICITV REFERENCE -TEST LCSO
NO RESTRICTIONS
-TOXICITV REFERENCE
-TGdCITY REFERENCE
-TOXICITV REFERENCE 'TEST LCSO
TEST LC50-1 /\Al
t»—'LAD>»-
TEST LC50—I \/
A15 A A i/
MIXING-»-cfL AD
r
RESTRICTIONS
r-»— Ht Fl Ml N( I > 11 SI Hi H HI Nrt
Y
-*—IFM >H)P ( HI M t > ft' MM ' Hill HillIM^—. T T
I- » I HI SI MIC t IONS
-»-H(l I H(N( t > It SI > ACUll CfllMRlON 1 L . . . 1
Figure Al. Flowchart for decisionmaking for aquatic disposal benthic imricts
(number near LAD .is paragraph discussing LAD)
-------
A4. If the local authority chooses to conduct additional tests to
assess the potential for contaminant impacts in the water column, the proce-
dures outlined in Figure Al should be followed. Water column evaluations are
based on the standard elutriate (paragraph 28). However, the local authority
must decide whether to take a chemical- or biological-based approach to evalua-
ting potential impacts on the water column. Chemical evaluations are appro-
priate when concern is primarily with chemicals for which water-quality
criteria have been established (Table C2) and there is little concern about
interactive effects of multiple contaminants. If the concern is primarily with
chemicals for which water-quality criteria have not been established, or'there
is concern about interactive effects of multiple contaminants, a biological
approach is preferred.
DECISIONS FROM CHEMICAL EVALUATIONS
A5. Chemical analyses of the elutriate are evaluated in comparison to
dissolved contaminant concentrations in reference water and to acute water-
quality criteria for contaminants for which criteria exist (Table C2). Acute
criteria are maximum concentrations that should not be exceeded and are appro-
priate because of the transient nature of dredged material contaminant
releases to the water column. Contaminants for which criteria exist are
evaluated separately from those for which criteria have not been established.
A6. When acute water-quality criteria exist for the contaminants of
concern, five conditions are possible (Figure Al):
a_. Concentrations of all dissolved contaminants in the test water
(elutriate) are less than or equal to the reference water and
less than or equal to the acute water-quality criterion for
each contaminant (Table C2).
_b_. Concentration of any dissolved contaminant in the test is
greater than in the reference water and less than QIC equal
to the acute water-quality criterion (Table C2).
Conditions £ and b_ lead to a DECISION OF NO RESTRICTIONS
required to protect against degradation of the water column
beyond existing reference site conditions.
c_. Concentration of any dissolved contaminant in the test is
less than or equal to the reference water and greater than
the acute water-quality criterion (Table C2).
d_. Concentration of any dissolved contaminant in the test is
equal to or greater than the reference water, and the reference
water is equal to or greater than che acute water quality cri-
terion (Table C2).
A5
-------
Since dilution to the criterion cannot occur under conditions £
and d (unless the receiving water for the discharge is not the
reference water and is less than the criterion), they lead to a
DECISION FOR RESTRICTIONS required to protect against contami-
nant impacts in the water column due to the proposed discharge.
Some potentially appropriate restrictions are described in
paragraphs 75 and 76.
e_. Concentration of any dissolved contaminant in the test is
equal to or greater than the acute water-quality criterion
(Table C2), and the reference water is less than the acute
water-quality criterion.
Since dilution to the criterion can occur (if the receiving
water for the discharge, which may or may not be the reference
water, is less than the criterion), this leads to a LOCAL
AUTHORITY DECISION as discussed in paragraph A7.
LOCAL AUTHORITY DECISION; RESTRICTIONS/NO RESTRICTIONS/CONSIDER MIXING
A7- Under the conditions of subparagraph A6e, dilution will occur at
the disposal site (if the receiving water for the discharge, which may or may
not be the reference water, is less than the criterion). Therefore, mixing
must be considered in order to scientifically assess the potential for water
column impacts to occur. However, in some cases, the local authority may
choose to reach a decision without considering mixing by assessing test
results in light of the increasing concern about potential contaminant impacts
in the water column in direct relation to the:
a_. Number of contaminants (for which criteria have been estab-
lished) exceeding reference concentrations.
_b. Number of contaminants (with criteria) exceeding acute
criteria.
£. Magnitude by which reference concentrations are exceeded.
cL Magnitude by which criteria are exceeded.
^. Toxicological importance of contaminants exceeding reference
concentrations and/or acute criteria. Contaminants that can
be objectively ranked in this manner are presented in Table C3.
f_. Proportion of sediment sampling sites in the dredging area be-
ing evaluated that have elutriate exceeding reference concen-
trations and/or acute criteria. (If a single composite sample
from the dredging area is analyzed, this factor drops from
consideration.)
In the case of subparagraph A6e, the local authority might choose, without
considering mixing, to reach a DECISION OF NO RESTRICTIONS required to protect
against contaminant impacts in the water column. This may be appropriate if
A6
-------
samples from only a j'ew sites have only a small number of contaminants of rel-
atively low toxicological concern exceeding the reference by a small amount
and are well below the acute criteria. In addition to the preceeding contam-
inant considerations, the discharge should also be subjectively assessed in
light of the mixing considerations of paragraph 34 before a decision of no
restrictions is reached. In the case of subparagraph A6e, the local authority
might also choose, without considering mixing, to reach a DECISION OF RESTRIC-
TIONS required to protect against contaminant impacts in the water column.
This may be appropriate if samples from a number of sites have several contam-
inants of relatively high toxicological concern exceeding the reference and
the criteria by a substantial margin. A decision for restrictions would be
particularly appropriate in cases where the water at the disposal site already
exceeded the criterion, making dilution to the criterion impossible. Some
potentially appropriate restrictions are described in paragraphs 75 and 76.
If the local authority desires to fully evaluate the potential for water column
impacts to occur, it will reach a DECISION FOR FURTHER EVALUATION by consider-
ing mixing as discussed in paragraph A9.
A8. Commencement Bay area authorities have tentatively decided to make
the local authority decision (LAD) discussed in paragraph A7 using the fol-
lowing quantitative approach. The quantitation was selected for use when
Commencement Bay area goals (paragraph 70) indicate the use of a relatively
pristine reference, as is the case in the example of Part III and Tables 3-21.
Other values may be necessary to achieve local goals that utilize a less
pristine reference. Although conceptually similar approaches could be taken
elsewhere, the approach and its quantitation would have to be tailored
specifically to local goals. The authors do not necessarily advocate either
quantitation of the guidance of paragraph A? or its quantitation in the fol-
lowing manner since the guidance considerations may be complexly interactive.
The approach described below is the initial approach tentatively selected by
Commencement Bay area authorities and should not be construed as final
Commencement Bay area guidance nor as implied guidance or a precedent for
actual LADs elsewhere.
a_. If 25 percent or less of the contaminants of concern (for
which criteria have been established) exceed reference, there
is cause for low concern. If 25 percent-90 percent of the con-
taminants of concern with criteria exceed reference, there is
A7
-------
cause for moderate concern. If 90 percent or move of the con-
taminants of concern with criteria exceed reference, there is
cause for high concern.
^b. If 25 percent or less of the contaminants of concern with cri-
teria exceed the criteria, there is cause for low concern. If
25 percent-?5 percent of the contaminants of concern with cri-
teria exceed the criteria, there is cause for moderate concern.
If 75 percent or more of the contaminants of concern with cri-
teria exceed the criteria, there is cause for high concern.
c^. If the contaminant of concern (with a criterion) that exceeds
reference by the greatest factor is less than or equal to
25 times reference concentration, there is cause for low con-
cern. If any contaminant of concern (with a criterion) is
25-100 times reference concentration, there is cause for moder-
ate concern. If any contaminant of concern (with a criterion)
is 100 or more times reference concentration, there is cause
for high concern.
_d_. If the contaminant of concern (with a criterion) that exceeds
its criterion by the greatest factor is less than or equal to
10 times its criterion, there is cause for low concern. If any
contaminant of concern (with a criterion) is 10-100 times its
criterion, there is cause for moderate concern. If any contam-
inant of concern (with a criterion) is 100 or more times its
criterion, there is cause for high concern.
&. If all contaminants of concern (with criteria) are rank 1 or 2
in Table C3, there is cause for low concern. If any contaminant
of concern (with a criterion) is rank 3 or 4 in Table C3, there
is cause for moderate concern. If any contaminant of concern
(with a criterion) is rank 5 or 6 in Table C3, there is cause
for high concern. (Unranked contaminants of concern are cause
for moderate concern unless there is additional evidence to
reasonably warrant a different level of concern.)
f_. If 50 percent or less of the sediment sampling sites in the
dredging area being evaluated have any contaminant of concern
(with a criterion) exceeding the reference or criterion, there
is cause for low concern. If more than. 50 percent of the sedi-
ment sampling sites in the area being evaluated have any con-
taminant of concern (with a criterion) exceeding the reference
or criterion, there is cause for high concern. (If a single
composite sample from the dredging area is analyzed, this fac-
tor drops from consideration.)
Findings of low concern in all factors, a_ through .£_, lead to a DECISION OF NO
RESTRICTIONS required to protect against contaminant impacts in the water col-
umn. A finding of high concern in half or more factors leads to a DECISION
OF RESTRICTIONS required to protect against contaminant impacts in the water
column. Some potentially appropriate restrictions are described in para-
graphs 75 and 76. All other combinations of findings lead to a DECISION FOR
FURTHER EVALUATION by considering mixing as discussed in paragraph A10.
A8
-------
DECISION FOR FURTHER EVALUATION; CONSIDER MIXING
A9. If the considerations of paragraph A7 lead to an evaluation of
mixing, the local authority must decide whether the size and configuration of
the mixing zone required to dilute the discharge to the water quality criteria
are acceptable. Mixing zone calculation is described in paragraphs 31-33 and
Appendix D. Note that mixing calculations must be based on the receiving water
for the discharge, which may or may not be the reference water. Mixing zone
evaluation is discussed in paragraphs 34-36 and can result in:
£. A mixing zone of acceptable size and configuration within
which the discharge will be diluted to less than the acute
water-quality criterion (Table C2). Acceptability of the
mixing zone is determined in light of the considerations in
paragraph 34 and paragraph A7 evaluated at the edge of the
mixing zone. This leads to a DECISION OF NO RESTRICTIONS
required to protect against possible contaminant impacts in
the water column.
^. The mixing zone within which the discharge will be diluted to
less than the acute water-quality criterion (Table C2) is of
unacceptable size and/or configuration. Acceptability of the
mixing zone is determined in light of the considerations in
paragraph 34 and paragraph A7 evaluated at the edge of the
mixing zone. This leads to a DECISION FOR RESTRICTIONS
required to protect against possible contaminant impacts in the
water column. Some potentially appropriate restrictions are
described in paragraphs 75 and 76.
A10. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph A9 using the following quantitative approach.
The quantitation was selected for use when Commencement Bay area goals (para-
graph 70) require the use of a relatively pristine reference, as is the case
in the example of Part III and Tables 3-21. Other values may be necessary to
achieve local goals that utilize a less pristine reference. Although con-
ceptually similar approaches could be taken elsewhere, the approach and its
quantitation would have to be tailored specifically to local goals. The
authors do not necessarily advocate either quantitation of the guidance of
paragraph A7 or its quantitation in the following manner since the guidance
considerations may be complexly interactive. The approach described below is
the initial approach tentatively selected by Commencement Bay area authorities
and should not be construed as final Commencement Bay area .guidance nor as
implied guidance or a precedent for actual LADs elsewhere.
A9
-------
a_. A DECISION OF NO RESTRICTIONS required to protect; against pos-
sible contaminant impacts in the water column is reached if the
mixing zone is•acceptable (paragraph 35) and there is cause
for low concern if any four of the six factors in paragraph A8
considered at the edge of the mixing zone.
b_. A DECISION OF RESTRICTIONS required to protect against possible
contaminant impacts in the water column is reached if the mixing
zone is unacceptable (paragraph 35) or there is cause for moder-
ate or high concern in any four of the six factors in para-
graph A8 considered at the edge of the mixing zone. Some
potentially appropriate restrictions are described in
paragraphs 75 and 76.
All. When acute water-quality criteria do not exist for contaminant(s)
of concern, two conditions are possible (Figure Al).
a_. Concentrations of all dissolved contaminants of concern in the
test water (elutriate) are less than or equal to the reference
water. This leads to a DECISION OF NO RESTRICTIONS required to
protect against degradation of the water column beyond existing
reference site conditions.
_b. Concentration of any dissolved contaminant in the test water
is greater than in the reference water. This leads to a LOCAL
AUTHORITY DECISION.
A12. LOCAL AUTHORITY DECISION; BIOASSAYS. Under the conditions of
subparagraph Allb, the local authority must decide whether to require bioas-
says. There is no basis for determining the environmental importance of a
contaminant that exceeds the reference concentration unless bioassays are
conducted. However; in some cases the local authority could choose to reach a
decision without conducting bioassays by assessing test results in light of
the increasing concern about potential contaminant impacts in the water column
in direct relation to the factors listed in paragraph A7. In the case of sub-
paragraph Allb, the local authority might choose, without conducting bioassays,
to reach a DECISION OF NO RESTRICTIONS required to protect against contaminant
impacts in the water column. This may be appropriate if samples from only a
few sites have a small number of contaminants exceeding the reference by a
small amount. Since there are no criteria, if bioassays are not considered
necessary on the above basis, there is no "target concentration" for a mixing
calculation. However, in addition to the contaminant considerations of para-
graph A7, the discharge should also be subjectively assessed in light of the
mixing considerations of paragraph 34 before a DECISION OF NO RESTRICTIONS is
reached. On the other hand, the local authority might choose, without con-
ducting bioassays, to reach a DECISION FOR RESTRICTIONS if samples from a
A10
-------
number of sites have several contaminants exceeding the reference by a sub-
stantial margin. Some potentially appropriate restrictions are described in
paragraphs 75 and 76. If the local authority desires to fully evaluate the
potential for water column impacts to occur, it will reach a DECISION FOR
FURTHER EVALUATION by conducting bioassays as evaluated in paragraph A14.
This will determine the effects of exceeding the reference for short periods
and will indicate possible interactive effects of multiple contaminants.
A13. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph A22 using the quantitative approach described
in paragraph A8. This quantitation was selected for use when Commencement Bay
area goals (paragraph 70) require the use of a relatively pristine reference,
as is the case in the example of Part III and Tables 3-21. Other values may
be necessary to achieve goals that utilize a less -pristine reference. Since
there are no water-quality criteria for the contaminants presently under con-
sideration, factors b_ and d are simply excluded from consideration, and the
other factors evaluated -as described in paragraph A8. If a DECISION FOR FUR-
THER EVALUATION is reached, bioassays must be conducted and evaluated as de-
scribed in paragraph A14. Although conceptually similar approaches to inter-
preting elutriate test results in the absence 'of water-quality criteria could
be taken elsewhere, the approach and its quantitation would have to be tailored
specifically to local goals. The authors do not necessarily advocate either
quantitation of the guidance of paragraph A12 or its quantitation in the above
manner since the guidance considerations may be complexly interactive. The
approach described above is the initial approach tentatively selected by Com-
mencement Bay area authorities and should not be construed as final
Commencement Bay area guidance nor as implied guidance or a precedent for
actual LADs elsewhere.
DECISIONS FROM BIOLOGICAL EVALUATIONS
A14. From this point on, the evaluation of potential water column
impacts is biological. It is at this point that testing begins if a biological
approach is initially chosen in paragraph A4 (Figure Al). Water column bio-
assays can result in four possible conditions:
a. Toxicity of the test water (elutriate) to all species is less
than or equal to the reference water and less than the LC50
(i.e., 50-percent toxicity is not reached in the test water).
This leads to a DECISION OF NO RESTRICTIONS required to protect
against contaminant impacts in the water column.
All
-------
b^. Toxicity of the test water to any species is less than or equal
to_ the reference water and equal to or greater than the LC50
(i.e., at least 50-percent toxicity is reached in the test
water). This leads to a DECISION FOR RESTRICTIONS required to
protect against possible contaminant impacts in the water col-
umn. Some potentially appropriate restrictions are described
in paragraphs 75 and 76.
c_. Toxicity of the test water to any species is greater than the
reference water and less than the LC50, or
cL Toxicity of the test water to any species is greater than the
reference water and equal to or greater than the LC50. (There-
fore, dilution to the LC50 is possible if the receiving water
for the discharge, which may or may not be the reference water,
is less than the LC50.)
Conditions £ and &_ lead to a LOCAL AUTHORITY DECISION.
LOCAL AUTHORITY DECISION; RESTRICTIONS/NO RESTRICTIONS/CONSIDER MIXING.
A15. Under the condition of subparagraphs A14c or d, dilution will
occur at the disposal site (if the receiving water for the discharge, which
may or may not be the reference water, is less than the LC50). Therefore,
mixing must be considered in order to scientifically assess the potential for
water column impacts to occur. However, in some cases the local authority
could choose to reach a decision without considering mixing by assessing test
results in light of the increasing concern about potential contaminant impacts
in the water column in direct relation to the:
£. Number of species bioassayed with the elutriate with toxicity
exceeding reference toxicity.
_b. Magnitude of test toxicity.
£. Magnitude by which reference toxicity is exceeded.
d^. Proportion of sediment sampling sites in the dredging area being
evaluated that have elutriates whose toxicity exceeds reference
toxicity. (If a single composite sample from the dredging area
is bioassayed, this factor drops from consideration.)
In the case of subparagraph AlAc, the local authority might choose, without
considering mixing, to reach a DECISION OF NO RESTRICTIONS required to protect
against contaminant impacts in the water column. This may be appropriate if
samples from only a few sites are toxic to a low number of species and the
toxicity only slightly exceeds reference toxicity and is well below the LC50.
In the case of subparagraph A14d, the local authority might choose, without
considering mixing, to reach a DECISION FOR RESTRICTIONS required to protect
against contaminant impacts in the water column. This may be appropriate if
samples from a number of sites are toxic to several species and the toxicity
A12
-------
exceeds the reference toxicity and SO percent by a substantial margin. Some
potentially appropriate restrictions are described in paragraphs 75-80. If
the local authority desires to fully evaluate the potential for water column
impacts to occur- it will reach a DECISION FOR FURTHER EVALUATION by consider-
ing mixing as discussed in paragraph A17.
A16. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph A15 using the following quantitative approach.
The quantitation was selected for use when Commencement Bay area goals
(paragraph 70) require the use of a relatively pristine reference, as is the
case in the example of Part III and Tables 2-21. Other values may be necessary
to achieve local goals that utilize a less pristine, reference. Although con-
ceptually similar approaches could be taken elsewhere, the approach and its
quantitation would have to be tailored specifically to local goals. The
authors do not necessarily advocate either quantitation cf the guidance of
paragraph A15 or its quantitation in the following manner since the guidance
considerations may be complexly interactive. The approach described below is
the initial approach tentatively selected by Commencement Bay area authorities
and should not be construed as final Commencement Bay area guidance nor as
implied guidance or a precedent for actual LADs elsewhere.
ja. If the elutriate produces greater toxicity than the reference
material in 20 percent or less of the test species, there is
cause for low concern. If elutriate toxicity exceeds reference
toxicity in 20 percent-80 percent of the test species, there is
cause for moderate concern.If elutriate toxicity exceeds ref-
erence toxicity in 80 percent or more of the test species,
there is cause for high concern.
b_. If the elutriate produces toxicity 20 percentage points* or
less above the control in all test species, there is cause for
low concern*. If elutriate toxicity is 20-40 percentage points*
above control toxicity in any species, there is cause for mod-
erate concern. If elutriate toxicity is 40 percentage points*
or more above control toxicity in any species, there is cause
for high concern.
c_. If the elutriate produces toxicity in all species less than or
equal to 2 times the reference material toxicity, there is
cause for low concern. If elutriate toxicity is 2-40 times
reference toxicity in any species, there is cause for moderate
concern. If elutriate toxicity is 40 or'more times the refer-
ence toxicity in any species, there is cause for high ~-">r<.c£rn.
* For example, if 2 of 100 control animals (2 percent) show toxicity. then
at least 12 of 100 test animals (12 percent) would have to show toxicity in
order for toxicity of the test sediment to be 10 percentage points above tl'e
control.
A13
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d_. If 50 percent or less of the sediment sampling sites in the
dredging area being evaluated have elutriate toxicity to any
species exceeding the reference toxicity, there is cause for
low concern. If more than 50 percent of the sediment sam-
pling sites in the area being evaluated have elutriate toxic-
ity to any species exceeding the reference toxicity, there is
cause for high concern. (If a single composite sample from
the dredging area is analyzed, this factor drops from
consideration.)
Findings of low concern in all factors £ through d_ lead to a DECISION OF NO
RESTRICTIONS required to protect against contaminant impacts in the water col-
umn. A finding of high concern in any three of the four factors leads to a
DECISION OF RESTRICTIONS required to protect against contaminant impacts in
the water column. Some potentially appropriate restrictions are described
in paragraphs 75-80. All other combinations of findings lead to a DECISION
FOR FURTHER EVALUATION by considering mixing as discussed in paragraph A18.
DECISION FOR FURTHER EVALUATION; CONSIDER MIXING
A17. If the considerations of paragraph A15 lead to an evaluation of
mixing, the local authority must decide whether the size and configuration of
the mixing zone required to dilute the discharge to less than the LC50 con-
centration are acceptable. Mixing zone calculation is described in para-
graphs 31-33 and Appendix D. Note that mixing calculations must be based on
the receiving water from the discharge, which may or may not be the reference
water. Mixing zone evaluation is discussed in paragraphs 34-36 and can result
in:
_a. A mixing zone of acceptable size and configuration within which
the discharge will be diluted to less than the LC50. Accept-
ability of the mixing zone is determined in light of the con-
siderations in paragraph 34 and paragraph A15 evaluated at the
edge of the mixing zone. This leads to a DECISION OF NO RE-
STRICTIONS required to protect against possible contaminant
impacts in the water column. (In the case of subparagraph A14c,
the LC50 is not exceeded even without consideration of mixing,
but if desired the mixing zone to dilute to some lower value,
such as LC20, can be calculated.)
]s. A mixing zone (within which the discharge will be diluted
to less than the LC50) that is of unacceptable size and/or
configuration. Acceptability of the mixing zone is determined
in light of the considerations in paragraph 34 and paragraph A15
evaluated at the edge of the mixing zone. This leads to a
DECISION FOR RESTRICTIONS required to protect against possible
contaminant impacts in the water column. Some potentially
appropriate restrictions are described in paragraphs 75-76.
A14
-------
A18. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph A15 using the following quantitative approach.
This quantitation was selected for use when Commencement Bay area goals (para-
graph 70) require the use of a relatively pristine reference, as is the case
in the example of Part III and Tables 3-21. Other values may be necessary to
achieve local goals that utilize a less pristine reference. Although concep-
tually similar approaches could be taken elsewhere, the approach and its quan-
titation would have to be tailored specifically to local goals. The authors
)
do not necessarily advocate either quantitation of the guidance of para-
graph A15 or its quantitation in the following manner since the guidance con-
siderations may be complexly interactive. The approach described below is the
initial approach tentatively selected by Commencement Bay area authorities and
should not be construed as final Commencement Bay area guidance nor as implied
guidance or a precedent for actual LADs elsewhere.
a.. A DECISION OF NO RESTRICTIONS required to protect against pos-
sible contaminant impacts in the water column is reached if
the mixing zone is acceptable (paragraph 35) and there is cause
for low concern in any three of the four factors in para-
graph A16 considered at the edge of the mixing zone.
_b. A DECISION OF RESTRICTIONS required to protect against possible
contaminant impacts in the water column is reached if the mix-
ing zone is unacceptable (paragraph 35) or_ there is cause for
moderate or TrTgh concern in any two of the four factors in
paragraph A16 considered at the edge of the mixing zone. Some
potentially appropriate restrictions are described in
paragraphs 75-76.
Benthic Evaluation
A19. .A thorough assessment of potential impacts should include both
chemical and biological evaluation of the material in question. This is ac-
complished in the water column evaluation by comparing chemical concentrations
to biologically derived water-quality criteria. However, in the case of non-
dissolved contaminants associated with deposited sediment, no biological-based
criteria are available for evaluating sediment chemistry data. Therefore,
chemical and biological data derived from the same sediment sample must be
evaluated in conjunction with each other in order to arrive at an adequate
assessment of potential impacts on the benthic environment (Figure A2). This
is accomplished by using a bulk or total sediment analysis for the specific
A15
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0
UJ
I-
NO RESTRICTIONS
SEDIMENT
-CHEMISTRY-
AND
TOXICITY
_ CHEMISTRY. REFERENCE _» TEST
TOXICITY REFERENCE _ TEST v 50%"
_ CHEMISTRY REFERENCE^TEST
TOXICITY REFERENCE TEST v 50%
CHEMISTRY: REFERENCE' TEST
TOXICITY REFERENCED TEST-50%
CHEMISTRY. REFERENCE- TEST
"TOXICITY REFERENCE TEST- 50%"
_CHEMISTRY REFERENCED TEST
"TOXICITY REFERENCE < TEST^50%
CHEMISTRY REFERENCE- TEST
TOXICITY. REFERENCE- TEST,; 50%
CHEMISTRY REFERENCE -TEST
"TOXICITY: REFERENCE _ TEST ,;5o%"
_CHEMISTRY: REFERENCE : TEST
TOXICITY REFERENCE - TEST s 50%
A20a
BIO-
ACCUMULATION
-REFERENCED TEST FDA
-REFERENCE- TEST- FDA
-REFERENCE TEST. NO FDAI
-REFERENCE > TEST, NO FDA»J
-REFERENCE TEST_FDA
-REFERENCE -TEST FDA
RESTRICTIONS
Figure A2. Flowchart for decisionmaking for aquatic disposal benthic impacts
(number near LAD is paragraph discussing LAD)
-------
contaminants of concern identified for that particular sediment and a toxicity
test of the whole sediment (paragraph 39).
DECISIONS FROM CHEMISTRY AND TOXICITY EVALUATIONS
A20. Chemical analyses of the test sediment are compared to similar
analyses of a sedimentologically similar reference sediment. Toxicity of the
test sediment is statistically compared to toxicity of the same reference
sediment to the same appropriately sensitive aquatic organisms. Benthic
chemistry and toxicity tests can result in eight possible combinations:
_a. Concentration of all contaminants of concern in the test sedi-
ment are less than or equal to the reference sediment, and
toxicity of the test sediment to all species is less than or
equal to the reference and less than 50 percentage points above
the control.* This leads to a LOCAL AUTHORITY DECISION. The
LAD might be NO RESTRICTIONS. This may be appropriate if
concentrations of all contaminants of concern in the test
sediment were considerably less than reference and toxicity of
the test sediment to all species was considerably less than
the reference. The LAD might be a DECISION FOR FURTHER
EVALUATION by assessing the potential for bioaccumulation as
discussed in paragraph A21. This might be appropriate if
concentrations of all contaminants of concern and toxicity to
all species equals reference.
b. Concentrations of any contaminant of concern in the test sedi-
ment are less than or equal to the reference sediment, and
toxicity of the test sediment to any species is greater than
the reference and less than 50 percentage points above the
control,* or
c. Concentrations of any contaminant of concern in the test sedi-
~~ ment are greater than the reference sediment, and toxicity of
the test sediment to any species is less than or equal to the
reference sediment and less than 50 percentage points above
the control,* or
d. Concentrations of any contaminant of concern in the test sedi-
~ ment are greater than the reference sediment, and toxicity of
the test sediment to any species is greater than the reference
sediment and less than 50 percentage points above the control.*
* For example, if 9 of 100 control animals (9 percent) show toxicity, then
at least 59 of 100 test animals (59 percent) would have to show toxicity
in order for toxicity of the test sediment to be 50 percentage points
above the control.
A17
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Conditions b_, £, and d_ lead to a DECISION FOR FURTHER EVALUA-
TION by assessing the potential for bioaccumulation of the
contaminants of concern from the test sediment (Figure A2),
as discussed in paragraph A21.
£. Concentrations of any contaminant of concern in the test sed-
iment are less them, or equal to the reference sediment, and
toxicity of the test sediment to any species is greater than
the reference and equal to or greater than 50 percentage points
above the control,* or
f_. Concentrations of any contaminant of concern in the test sedi-
ment are greater than the reference sediment, and toxicity of
the test sediment to any species is greater than the reference
and equal to or greater than 50 percentage points above the
control, or
£. Concentrations of any contaminant of concern in the test sed-
iment are less than or equal to the reference sediment, and
toxicity of the test sediment to any species is less than or
equal to the reference sediment and equal to or greater than
50 percentage points above the control,* or
_h. Concentrations of any contaminant of concern in the test sedi-
ment are greater than the reference sediment, and toxicity of
the test sediment to any species is less than or equal to the
reference sediment and equal to or greater than 50 percentage
points above the control.*
Conditions e_, f_, £, and h_ lead to a DECISION FOR RESTRICTIONS
required to protect against possible contaminant degradation of
the benthic environment beyond existing reference site condi-
tions. Some potentially appropriate restrictions are described
in paragraphs 77-79.
DECISIONS FROM BIOACCUMULATION EVALUATIONS
A21. The local authority must evaluate the potential for bioaccumulation
of contaminants from sediments as indicated by the procedures of paragraph 40.
Bioaccumulation tests can result in six conditions:
_a. Concentrations of all contaminants of concern in the tissues of
any species exposed to the test sediment are less than or equal
to concentrations in animals exposed to the reference sediment
and less than FDA-type limits (Table Cl). This leads to a
DECISION OF NO RESTRICTIONS required to protect against con-
taminant impacts due to sediment deposits.
b^. Concentration of any contaminant of concern in the tissues of
any test species are greater than reference animals and equal
to or greater than FDA-type limits (Table Cl), or
* For example, if 9 of 100 control animals (9 percent) show toxicity, then
at least 59 of 100 test animals (59 percent) would have to show toxicity
in order for toxicity of the test sediment to be 50 percentage points
above the control.
A18
-------
c_. Concentrations of any contaminant of concern in the tissues of
any test species are less than or equal to reference animals
and equal to or greater than FDA-type limits (Table Cl).
Conditions b_ and £ lead to a DECISION FOR RESTRICTIONS required
to protect against possible contaminant impacts of sediment
deposits. Some potentially appropriate restrictions are de-
scribed in paragraphs 77-79.
_d. Concentrations of any contaminant of concern in the tissues of
any test species are greater than reference animals and less
than FDA-type limits (Table Cl), or
e^. Concentrations of any contaminant of concern in the tissue of
any test species are greater than reference animals and no_
FDA-type limits have been established (Table Cl), or
_f. Concentrations of any contaminant of concern in the tissues of
any test species are less than OP equal to reference animals
and no FDA-type limits have been established (Table Cl).
Conditions d_, £, and f. lead to a LOCAL AUTHORITY DECISION.
LOCAL AUTHORITY DECISION: NEED FOR RESTRICTIONS
A22. At present it is not possible to provide sufficient scientific
basis for deciding on the need for restrictions on the cases of subpara-
graphs A21d, e, and f. Therefore, the local authority must make an administra-
tive decision using the available scientific information and locally important
concerns. In interpreting bioaccumulation data, scientific concern over
potential adverse impacts associated with bioaccumulation increases in direct
relation to:
a. Number of contaminants of concern bioaccumulated to concentra-
tions exceeding reference levels.
b. Number of phylogenetic groups of species showing bioaccumula-
~ tion to concentrations exceeding reference levels.
c. Magnitude of contaminant concentrations in tissues of test
organisms.
d. Magnitude of bioaccumulation above reference levels.
e. Toxicological importance of contaminants bioaccumulated to con-
~~ centrations exceeding reference levels. Contaminants which can
be objectively ranked in this manner are presented in Table C3.
f. Number of species showing toxicity when exposed to the same
test sediment.
£. Magnitude of toxicity caused by the same test sediment.
h. Proportion of sediment sampling sites in the area being
"~ evaluated which show toxicity exceeding reference or bio-
accumulation to concentrations exceeding reference levels.
A19
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When bioaccumulation test results are those of subparagraphs A21d, e, and f,
these considerations may lead the local authority to a DECISION FOR RESTRIC-
TIONS to protect from possible adverse contaminant impacts from sediment de-
posits on the aquatic environment. Some potentially appropriate restrictions
for such cases are discussed in paragraphs 75 and 77-79. The local authority
may also reach a DECISION OF NO RESTRICTIONS required to protect against
possible contaminant impacts from sediment deposits.
A23. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph A22 using the following quantitative approach.
This quantitation was selected for use when Commencement Bay area goals
(Paragraph 70) require the use of a relatively pristine reference, as is the
case in the example of Part III and Tables Z-22. Other values may be neces-
sary to achieve local goals that utilize a less pristine reference. Although
conceptually similar approaches could be taken elsewhere, the approach and its
quantitation would have to be tailored specifically to local goals. The
authors do not necessarily advocate either quantitation of the guidance of
paragraph A22 or its quantitation in the following manner since the guidance
considerations may be complexly interactive. The approach described below is
the initial approach tentatively selected by Commencement Bay area authorities
and should not be construed as final Commencement Bay area guidance nor as im-
plied guidance or a precedent for actual LADs elsewhere.
a. Number of contaminants above reference. If 25 percent or less
of the contaminants of concern are bioaccumulated in any spe-
cies to concentrations exceeding those in reference animals,
there is cause for low concern. If more than 25 percent of
the contaminants of concern in any species exceed reference
animals, there is cause for high concerri.
b. Number of species. If the dredged material produces higher
tissue concentrations of any contaminant than the reference
material in 20 percent or less of the test species, there
is cause for low concern. If the dredged material produces
higher concentrations of any contaminant than the reference
material in more than 20 percent of the test species, there
is cause for high concern.
£. Tissue contaminant concentrations. If the dredged material
produces tissue contaminant concentrations of 0. 5 ug/g wet
weight or less of all contaminants in all species, there is
cause for low concern. If the dredged material produces
tissue contaminant concentrations greater than 0.5 ug/g wot
weight of any contaminant in any species, there is cause for
high concern.
A20
-------
Magnitude above reference. If the dredged material produces
tissue concentrations of all contaminants in all species 10 or
less times higher than the reference tissue concentrations,
there is cause for low concern. If the dredged material tissue
concentrations of any contaminant in any species are more than
10 times the reference concentrations, there is cause for high
concern.
Toxicological importance. If the contaminants of concern bio-
accumulated to concentrations exceeding reference levels in
any species are rank 1-3 in Table C3, there is cause for low
concern. If the bioaccumulated contaminants in any species
are unranked or rank 4-6 in Table C3, there is cause for high
concern.
Toxicity above reference. If the dredged material produces
more toxicity than the reference material in 20 percent or less
of the deposited sediment bioassay species, there is cause for
low concern. If deposited dredged material toxicity exceeds
reference toxicity in more than 20 percent of the test species,
there is cause for high concern.
Toxicity above control. If the deposited dredged material pro-
duces toxicity 20 percentage points* or less above the control
in all test species,there is cause for low concern. If de-
posited dredged material toxicity is more than 20 percentage
points* above control in any species, there is cause for high
concern.
Number of sampling sites producing bioaccumulation. If 50 per-
cent or less of the sediment sampling sites in the dredging
area being evaluated produce bioaccumulation of any contaminant
in any species exceeding the reference sediment, there is cause
for low concern. If more than 50 percent of the sediment sam-
pling sites produce bioaccumulation of any contaminant of con-
cern in any species exceeding the reference sediment, there is
cause for high concern.
Number of sampling sites producing toxicity. If 50 percent or
less of the sediment sampling sites in the area being evaluated
produce toxicity to any species exceeding the reference sedi-
ment, there is cause for low concern. If more than 50 percent
of the sediment sampling sites produce toxicity to any species
exceeding the reference sediment, there is cause for high con-
cern. (If a single composite sample from the dredging area is
analyzed, factor _h and ±^ drop from consideration.)
Number of contaminants in sediment above reference. If the
bulk sediment concentration of 50 percent or less of the con-
taminants of concern is higher in the dredged material than
For example, if 6 of 100 control animals (6 percent) show toxicity, then
at least 26 of 100 test animals (26 percent) would have to show toxicity
in order for toxicity of the test sediment to be 20 percentage points above
the control.
A21
-------
the reference material, there is cause for low concem. If
the bulk sediment concentration of more than 50 percent of
the contaminants oi concern is higher in the dredged material
than in the reference material, there is cause for high
concern.
_k. Magnitude above reference-sediment metals. If the metal con-
taminant of concern with the highest bulk sediment concentra-
tion in the dredged material is 5 or less times higher than
in the reference material, there is cause for low oonoern,
If the metal contaminant of concern with the highest bulk
sediment concentration in the dredged material is more than
5 times higher than in the reference material, there is cause
for hTgh concern.
^. Magnitude above reference-sediment organics. If the organic
contaminant of concern with the highest TOC-normalized bulk
sediment concentration in the dredged material is 10 or less
times higher than in the reference material, there is cause for
low concern. If such concentrations in the dredged material
are more than 10 times higher than in the reference, there is
cause for high concern.
Findings of low concern in more than half the factors lead to a DECISION OF
NO RESTRICTIONS required to protect from possible adverse impacts of sediment
deposits on the aquatic environment. A finding of high concern in more than
half the factors leads to a DECISION OF RESTRICTIONS required to protect from
possible adverse contaminant impacts of sediment deposits on the aquatic envi-
ronment. Some potentially appropriate restrictions for such cases are dis-
cussed in paragraphs 75 and 77-79.
A22
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APPENDIX B: DECISIONMAKING FRAMEWORK FOR UPLAND DISPOSAL
CONTENTS
Effluent Quality Tests B3
Decisions from effluent chemical evaluations B6
Local authority decision: restrictions/no restrictions/
consider .mixing B7
Decision for further evaluation: consider mixing B9
Local authority decision: bioassays Bll
Decisions from effluent biological evaluations B12
Local authority decision: restrictions/no restrictions/
consider mixing B13
Decision for further evaluation: consider mixing B15
Surface Runoff Quality Tests B16
Decisions from surface runoff chemical evaluations B18
Local authority decision: restrictions/no restrictions/ ;
consider mixing B19
Decision for further evaluation: consider mixing B21
Local authority decision: bioassays B23
Decisions from surface runoff biological evaluations B24
Local authority decision: restrictions/no restrictions/
consider mixing B24
Decision for further evaluation: consider mixing B27
Leachate Quality Tests B28
Leachate seepage into a receiving water body B29
Decisions from leachate seepage chemical evaluations B29
Local authority decision: restrictions/no restrictions/
consider mixing B31
Decision for further evaluation: consider mixing B3A
Local authority decision: restrictions/no restrictions/
consider bioassays B35
Decisions from leachate biological evaluations B36
Local authority decision: restrictions/no restrictions/
consider mixing B37
Decision for further evaluation: consider mixing B39
Decisions for leachate into drinking water B40
Local authority decision: restrictions/no restrictions B42
Decisions for leachate into nonpotable ground water B45
Local authority decision: restrictions/no restrictions/
consider bioassays B45
Decision for further evaluation: bioassays B47
Local authority decision: restrictions/consider mixing. B47
Decision for further evaluation: consider mixing B48
Plant Uptake Tests B48
Decisions from plant uptake/bioassay (tests B48
Decisions from DTPA-sediment extraction tests . . . B50
* NOTE: Alphanumeric identification of pages, paragraphs, and figures was
used in the appendices to distinguish them from the simple numbers
used as identification of main-text pages, paragraphs, figures, and
tables. Thus references to simple numbers in the appendices refer to
similarly numbered items in the main text.
Bl
-------
Local authority decision: restrictions/no restrictions/
consider bioassays B50
Decisions from plant bioassay evaluations B52
Local authority decision: restrictions/consider
bioaccumulation B53
Decisions from plant bioaccumulation evaluations B53
Local authority decision: restrictions/no restrictions/
consider total plant uptake B55
Decisions from total plant uptake evaluations B57
Animal Uptake Tests B59
Decisions from animal uptake/bioassay tests B59
Decisions from animal toxicity evaluations ... B59
Decisions from animal bioaccumulation evaluations . B61
Local authority decision: restrictions/no restrictions/
consider total animal uptake B62
Decisions from total animal uptake evaluations B64
Human Exposure Evaluation B66
B2
-------
APPENDIX B: DECISIONMAKING FRAMEWORK FOR UPLAND DISPOSAL
Bl. There are six aspects of upland disposal that require consideration
as shown in Figure Bl. At this time, there are only two simplified laboratory
tests that indicate a potential for contaminant mobility from sediment to be
dredged into two of these aspects, effluent water quality and plant uptake.
There are no other existing simplified laboratory tests to address contaminant
mobility into surface runoff, leachate water quality, or animal uptake. Re-
search is needed to develop those tests. There are more sophisticated labora-
tory tests that are recommended for surface runoff and plant and animal uptake
but no specified leachate tests. Research is being initiated at the WES to
address leachate testing. Potential human exposure can be evaluated by com-
paring the total concentration of contaminants in the dredged material to re-
cently tabulated critical concentrations of contaminants of concern for human
exposure.
,B2. There are four flowcharts (Figures B2-B5) that show decision points
for the three water-quality aspects of upland disposal. Two additional flow-
charts (Figures. B6 and B7) show decision points for plant and animal aspects
of upland disposal. Figure B8 shows decision points for potential human
exposure.
B3. The first tests that should be conducted on a contaminated dredged
material are a total bulk chemical analysis if not already performed (para-
graph 72), a modified elutriate test (paragraph 45), and a DTPA extraction
procedure (paragraph 62). The results of these tests will give an indication
of the need for restrictions on human exposure, restrictions on effluent qual-
ity control, and further testing of plant uptake. These test results are
limited in relationship to estimating surface runoff quality, leachate quality,
or animal uptake.
Effluent Quality Tests
B4. Concerns about contaminant impacts from upland disposal site ef-
fluent water have centered on short-term impacts in the receiving water during
the disposal operation. The decision points'and the tests appropriate for de-
termining potential impacts from disposal site effluent water are shown in
Figure B2. The local authority must decide whether to take a chemical or bio-
logical based approach to evaluating the potential impacts of the disposal
site effluent on the receiving water. Chemical evaluations are appropriate
B3
-------
w
-e-
UPLAND
DISPOSAL
EFFLUENT
QUALITY
MODIFIED
"ELUTRIATE"
•FIGURE B2
SURFACE RUNOFF
QUALITY
LEACHATE
• QUALITY •
FIGURE 83
^-RECEIVING WATER
-^-GROUNDWATER
PLANT
UPTAKE »* FIGURE B6
ANIMAL
UPTAKE ».— FIGURES?
FIGURE B4
FIGURE B5
Figure Bl. Summary flowchart for decisionmaking for upland disposal
-------
OT
Ul
DUALITY WATER \^
vBitH|CAL
/EVALUATION *
BIOLOGICAL
EVALUATION
RESTRICTIONS p TO
API 2
QUALITY * X *
TRITFRIA 1 I .
1— REFERENCE TEST-»-| NO RESTRICTIONS LTOX
1 • 1 MJ RESTRICTIONS
WATER i ,, -, 1
QUALITY ...„ /\V •„«„, . ^A
CRITERIA ^ ' '• • « «i«™. . <^
fc 1 ( S I > K t f I H f M I > - 1 1 , T I C H . H H It IN . .-. * f
>HH «S.«.K,«
— TOXICITY-. REFERENCE _ TEST LC50
-TOXICITY: REFERENCE TEST LCSO
-TOXiCITVt REFERENCE TEST LC50
-TOXICITY: REFERENCE TEST LCSO
NO RESTRICTIONS
RESTRICTIONS
Figure B2. Flowchart for decisionmaking for effluent water quality
(number near LAD is paragraph discussing LAD)
-------
when concern is primarily with contaminants for which water-quality criteria
have been established (Table C2) and there is little concern about interactive
effects of multiple contaminants. If the concern is primarily with chemicals
for which water-quality criteria have not been established or there is concern
about interactive effects of multiple contaminants, a biological approach is
preferred.
DECISIONS FROM EFFLUENT CHEMICAL EVALUATIONS
B5. Chemical analyses of the effluent (modified elutriate) are
evaluated in comparison to dissolved contaminant concentrations in a reference
water which could be the receiving water or another appropriate local authority
decision (LAD) reference water, and to acute water-quality criteria for con-
taminants for which criteria exist (Table C2). Acute criteria are maximum
concentrations that should not be exceeded and are appropriate because of the
transient nature of effluent water discharges into the receiving water. Con-
taminants for which criteria exist are evaluated separately from those for
which criteria have not been established.
B6. When acute water-quality criteria exist for the contaminants of
concern, five conditions are possible (Figure B2):
a.. Concentrations of all dissolved contaminants in the test ef-
fluent are less than or equal to the reference water and less
than the acute water-quality criterion for each contaminant
(Table C2).
b_. Concentration of any dissolved contaminant in the test is
greater than in the reference water and less than the acute
water-quality criterion (Table C2).
Conditions a_ and b^ lead to a DECISION OF NO RESTRICTIONS re-
quired to protect against degradation of the water column
beyond existing reference site conditions.
c. Concentration of any dissolved contaminant in the test is
equal to or greater than the reference water, and the reference
water is equal to or greater than the acute water-quality cri-
terion (Table C2).
_d_. Concentration of nnu dissolved contaminant in the test is less
than ur equal to the reference water and equal to or greater
than the acute water-quality criterion (Table C2). Since
dilution to the criterion cannot occur under conditions £ and
d_ (unless the receiving water for the discharge is not the
reference water and is less than the criterion), conditions £
or d_ lead to a DECISION FOR RESTRICTIONS required to protect
against contaminant impacts in the water column due to the
proposed discharge. Some potentially appropriate restrictions
are described in paragraphs 81-93.
B6
-------
e_. Concentrations of any dissolved contaminant in the test is
equal to or greater than the acute water quality criterion
(Table C2) and the reference water is less than the acute
water quality criterion. Since dilution to the criterion can
occur (if the receiving water for the discharge, which may or
may not be the reference water, is less than the criterion),
this leads to a LOCAL AUTHORITY DECISION as discussed in
paragraph B7.
LOCAL AUTHORITY DECISION; RESTRICTIONS/NO RESTRICTIONS/CONSIDER MIXING
B7. Under the conditions of subparagraph B6e, dilution will occur when
the disposal site effluent enters the receiving water (if the receiving water
for the discharge, which may or may not be the reference water, is less than
the criterion). Consequently, mixing must be considered in order to scientif-
ically assess the potential for effluent discharge impacts to occur. However,
in some cases the local authority may choose to reach a decision without con-
sidering mixing by assessing test results in light of the increasing concern
about potential contaminant impacts from the disposal site effluent discharge
in direct relation to:
a_. Number of contaminants (for which criteria have been estab-
lished) exceeding reference concentrations.
t). Number of contaminants (with criteria) exceeding acute
criteria.
£_. Magnitude by which reference concentrations are exceeded.
ji. Magnitude by which criteria are exceeded.
e. Toxicological importance of contaminants exceeding reference
concentrations and/or acute criteria. Contaminants that
can be objectively ranked in this manner are presented in
Table C3.
f. Proportion of sediment sampling sites in the dredging area
being evaluated that have test modified elutriates exceeding
reference concentrations and/or acute criteria. (If a single
composite sample from the dredging area is analyzed, this fac-
tor drops from consideration.)
In the case of subparagraph B6e, the local authority might choose, without
considering mixing, to reach a DECISION OF NO RESTRICTIONS required to protect
against contaminant impacts in the receiving water. This may be appropriate
if samples from only a few sites have only a small number of contaminants of
relatively low toxicolog'ical concern exceeding the reference by a small amount
and are well below the acute criteria. In the case of subparagraph B6e, the
local authority might also choose, without considering mixing, to reach a
DECISION FOR RESTRICTIONS required to protect against contaminant impacts in
B7
-------
the receiving water. This may be appropriate if samples from a number of
sites have several contaminants of relatively high toxicological concern ex-
ceeding the reference and the criteria by a substantial margin. A decision
for restrictions would be particularly appropriate in cases where the receiv-
ing water already exceeded the criterion, making dilution to the criterion
impossible. Some potentially appropriate restrictions are described in para-
graphs 81-93. If the local authority desires to fully evaluate the potential
for receiving water impacts to occur, it will reach a DECISION FOR FUR-
THER EVALUATION by considering mixing zs discussed in paragraph B9.
B8. Commencement Bay area authorities have tentatively decided to make
the local authority decision (LAD) discussed in paragraph B7 using the follow-
ing quantitative approach. This quantitation was selected for use when
Commencement Bay area goals (paragraph 70) require the use of a relatively
pristine reference, as is the case in the example.in Part III and Tables 3-21.
Other values may be necessary to achieve local goals that utilize a less
pristine reference. Although conceptually similar approaches could be taken
elsewhere, the approach and its quantitation would have to be tailored
specifically to local goals. The authors do not necessarily advocate either
quantitation of the guidance of paragraph B7 or 'its quantitation in the fol-
lowing manner since the guidance considerations may .be complexly interactive.
The approach described below is the initial approach tentatively selected by
Commencement Bay area authorities and should not be construed as final
Commencement Bay area guidance nor as implied guidance or a precedent for
actual IADs elsewhere.
a.. Number of contaminants above reference. If 25 percent or less
of the contaminants of concern (for which criteria have been
established) exceed reference, there is cause for low concern.
If 25 percent-90 percent of the contaminants of concern with
criteria exceed reference, there is cause for moderate concem.
If 90 percent or more of the contaminants of concern with cri-
teria exceed reference, there is cause for high concern.
Jb. Number of contaminants above criteria. If ££ percent or less
of the contaminants of concern with criteria exceed the cri-
teria, there is cause for low concern. If 25 percent-?5 per-
cent of the contaminants of concern with criteria exceed the
criteria, there is cause for moderate concern. If 75 percent
or more of the contaminants of concern with criteria exceed
the criteria, there is cause for high concern.
c_. Magnitude above reference. If the contaminant of concern
(with a criterion) that exceeds reference by the greatest fac-
tor is less than or equal to 25 times reference concentration,
B8
-------
there is cause for low concern. If any contaminant of concern
(with a criterion) is 26-100 times reference concentration,
there is cause for moderate concern. If any contaminant of
concern (with a criterion) is 100 or more times reference con-
centration, there is cause for high concern",
d^. Magnitude above criterion. If the contaminant of concern
(with a criterion) that exceeds its criterion by the greatest
factor is less than or equal to 10 times the criteria, there
is cause for low concern.If any contaminant of concern (with
a criterion) is 10-100 times ,the criteria, there is cause for
moderate concern. If any contaminant of concern (with a cri-
terion) is 100 or more times the criterion, there is cause for
high concern.
e^, Toxicological importance. If all contaminants of concern
(with criteria) are rank 1 or 2 in Table C3, there is cause
for tow concern. If any contaminant of concern (with a cri-
terion) is rank 3 or 4 in Table C3, there is cause for moder-
ate concern. If any contaminant of concern (with a criterion)
is rank 5 or 6 in Table C3, there is cause for high concern.
(Unranked contaminants of concern are cause for moderate con-
cern unless there is additional evidence to reasonably warrant
a different level of concern.)
f_. Number of sampling sites. If 50 percent or less of the sedi-
ment sampling sites in the dredging area being evaluated have
any contaminant of concern (with a criterion) exceeding the
reference or criterion, there is cause for low concern. If
more than 50 percent of the sediment sampling sites in the
area being evaluated have any contaminant of concern (with
a criterion) exceeding the reference or criterion, there
is cause for high concern. (If a single composite sample
from the dredging area is analyzed, this factor drops from
consideration.)
Findings of low concern in all factors, a_ through f_, lead to a DECISION OF NO
RESTRICTIONS required to protect against contaminant impacts in the water col-
umn". A rinding of high concern in any four of the six factors, a_ through f_,
leads to a DECISION OF RESTRICTIONS required to protect against contaminant
impacts in the water column. Some potentially appropriate restrictions are
described in paragraphs 81-93. All other combinations of findings lead to a
DECISION FOR FURTHER EVALUATION by considering mixing as discussed in para-
graph B9.
DECISION FOR FURTHER EVALUATION; CONSIDER MIXING
B9. If the considerations of paragraph B7 lead to an evaluation of
mixing, the local authority must decide whether the size and configuration of
the mixing zone required to dilute the discharge to the water-quality criteria
are acceptable. Mixing zone calculation is described in paragraphs 31-33 and
B9
-------
Appendix D. Note that mixing calculations must be based on the receiving water
for the discharge, which may or may not be the reference water. Mixing zone
evaluation is discussed in paragraphs 34-36 and can result in:
a. A mixing zone of acceptable size and configuration within
which the discharge will be diluted to less than the acute
water quality criterion (Table C2). Acceptability of the mix-
ing zone is determined in light of the considerations of para-
graph 34 and paragraph B7 evaluated at the edge of the mixing
zone. This leads to a DECISION OF NO RESTRICTIONS required to
protect against possible contaminant impacts in the receiving
water.
b. A mixing zone within which the discharge will be diluted to
less than the acute water-quality criterion (Table C2) is of
unacceptable size or configuration. Acceptability of the mix-
ing zone is determined in light of the considerations of para-
graph 34 and paragraph B7 evaluated at the edge of the mixing
zone. This leads to a DECISION FOR RESTRICTIONS required to
protect against possible contaminant impacts in the receiving
water. Some potentially appropriate restrictions are de-
scribed in paragraphs 81-93.
BIO. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph B9 using the following quantitative approach.
This quantitation was selected for use when Commencement Bay area goals
(paragraph 70) require the use of a relatively pristine reference, as is the
case in the example in Part III and Tables 3-21. Other values may be neces-
sary to achieve local goals that utilize a less pristine reference. Although
conceptually similar approaches could be taken elsewhere, the approach and its
quantitation would -have to be tailored specifically to local goals. The au-
thors do not necessarily advocate either quantitation of the guidance of para-
graph B9 or its quantitation in the following manner since the guidance con-
siderations may be complexly interactive. The approach described below is the
initial approach tentatively selected by Commencement Bay area authorities and
should not be construed as final Commencement Bay area guidance nor as implied
guidance or a precedent for actual LADs elsewhere.
a. A DECISION OF NO RESTRICTIONS required to protect against pos-
sible contaminant impacts in the water column is reached if
the mixing zone is acceptable (paragraph 35) and there is
cause for low concern in any four of the six factors in
paragraph B8 considered at the edge of the mixing zone.
b. A DECISION OF RESTRICTIONS required to protect against pos-
sible contaminant impacts in the water column is reached if
the mixing zone is unacceptable (paragraph 35) 2£ there is
cause for moderate or high concern in any four of the six
factors in paragraph B8 considered at the edge of the mixing
BIO
-------
zone. Some potentially appropriate restrictions are described
in paragraphs 81-93.
fill. When acute water-quality criteria do not exist for contaminants of
concern, two conditions are possible (Figure B2):
_a. Concentrations of alt dissolved contaminants of concern in the
test effluent are less than or equal to the receiving water
(or reference water). This leads to a DECISION OF NO RESTRIC-
TIONS required to protect against degradation of the receiving
water beyond existing reference site conditions.
_b_. Concentrations of any dissolved contaminant in the test efflu-
ent is greater than in the receiving water (or reference
water). This leads to a LOCAL AUTHORITY DECISION.
LOCAL AUTHORITY DECISION; BIOASSAYS
B12. Under the conditions of subparagraph Bllb there is no available
information for determining the environmental importance of a contaminant
that exceeds the reference concentration. This can be determined with bio-
assays. However, in some cases the local authority may choose to reach a
decision without conducting bioassays by assessing test results in light of
the increasing concern about potential contaminant impacts in the receiving
water in direct relation to the factors listed in paragraph B7. In the case
of subparagraph Bllb, the local authority might choose, without conducting
bioassays, to reach a DECISION OF NO RESTRICTIONS required to protect against
contaminant impacts in the receiving water. This may be appropriate if samples
from only a few sites have a small number of contaminants exceeding the refer-
ence by a small amount. Since there are no criteria, if bioassays are not
considered necessary-on the above basis, there is no "target concentration"
for a mixing zone calculation. However, in addition to the contaminant con-
siderations of paragraph B7, the effluent discharge should be subjectively
assessed in light of the mixing zone considerations of paragraph 34 before a
decision of no restrictions is reached. On the other hand, the local authority
might choose, without conducting bioassays, to reach a DECISION FOR RESTRIC-
TIONS required to protect contaminant impacts in the receiving water. This
may be appropriate if samples from a number of sites have several contaminants
exceeding the reference by a substantial margin. Some potentially appropriate
restrictions are described in paragraphs 81-93. If the local authority desires
to fully evaluate the potential for receiving water impacts to occur, it will
reach a DECISION FOR FURTHER EVALUATION by conducting bioassays as described
in paragraph B14.
Bll
-------
B13. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph B12 using the quantitative approach described
in paragraph B8. This quantitation was selected for use when Commencement Bay
area goals (paragraph 70) require the use of a relatively pristine reference,
as is the case in the example in Part III and Tables 3-21. Other values may
be necessary to achieve local goals that utilize a less pristine reference.
Since there are no water-quality criteria for the contaminants presently under
consideration, factors b_ and d_ are simply excluded from consideration, ard the
other factors evaluated as described i;\ paragraph B8. If a DECISION FOR
FURTHER EVALUATION is reached, bioassays must be. conducted and evaluated as
aescribed in paragraph B14. Although conceptually similar approaches to
interpreting test results in the absence of water-quality criteria could be
taken elsewhere, the approach and its quantitation would have to be tailored
specifically to local goals. The authors do not necessarily advocate either
quantitation of the guidance of paragraph B12 or its quantitation in the above
manner since the guidance considerations may be complexly interactive. The
approach described above is the initial approach tentatively selected by
Commencement Bay area authorities and should not be construed as final Com-
mencement Bay area guidance nor as implied guidance or a precedent for actual
IADs elsewhere.
DECISIONS FROM EFFLUENT BIOLOGICAL EVALUATIONS
B14. From this point on, the evaluation of potential effluent impacts
on the receiving water is biological. It is at this point that testing begins
if a biological approach is initially chosen in paragraph B4 (Figure B2).
Effluent (modified elutriate) bioassays can result in four possible conditions:
a_. Toxicity of the test effluent (modified elutriate) to all
species is less than or equal to the reference .water and less
than the LC50 (i.e., 50-percent toxicity is not reached in the
test water). This leads to a DECISION OF NO RESTRICTIONS re-
quired to protect against contaminant impacts in the receiving
water.
_b. Toxicity of the test effluent to any species is less than or
equal to the reference water and equal to or greater than the
LC50 (i.e., at least 50-percent toxicity is reached in the test
water). This leads to a DECISION FOR RESTRICTIONS required to
protect against contaminant impacts in the receiving water.
Some potential appropriate restrictions are described In para-
graphs 81-93.
£. Toxicity of the test effluent to any species is greater than
the reference water and less than the LC50, or
B12
-------
d. Toxicity of the test effluent to any spcies is greater than
the reference water and equal to or greater than the LC50.
(Therefore, dilution to the LC50 is possible if the receiving
water for the discharge, which may or may not be the reference
water, is less than the LC50.)
Conditions c and d lead to a LOCAL AUTHORITY DECISION.
LOCAL AUTHORITY DECISION; RESTRICTIONS/NO RESTRICTIONS/CONSIDER MIXING
B15. Under the conditions of subparagraph B14c or d, dilution will occur
when the disposal site effluent discharge enters the receiving water (if the
receiving water for the discharge, which may or may not be the reference water,
is less than the LC50). Consequently, mixing must be considered in order to
scientifically assess the potential for receiving water impacts to occur.
However, in some cases the local authority may choose to reach a decision,
without considering mixing, by assessing test results in light of the increas-
ing concern about potential contaminant impacts in the receiving water in
direct relation to:
ji. Number of species bioassayed with the effluent with toxicity
exceeding reference toxicity.
b_. Magnitude of test toxicity.
£. Magnitude by which reference toxicity is exceeded.
ci. Proportion of sediment sampling sites in the dredging area
being evaluated that have effluents whose toxicity exceeds
reference toxicity. (If a single composite sample from the
dredging area is bioassayed, this factor drops from
consideration.)
In the case of subparagraph B14c, the local authority may choose, without con-
sidering mixing, to reach a DECISION OF NO RESTRICTIONS required to protect
against contaminant impacts in the receiving water. This may be appropriate
if samples from only a few sites are toxic to a low number of species and the
toxicity only slightly exceeds reference toxicity and is well below 50 per-
cent. In the case of B14d, the authority may choose, without considering mix-
ing, to reach a DECISION FOR RESTRICTIONS required to protect against contami-
nant impacts in the receiving water. This may be appropriate if samples from
a number of sites are toxic to several species and the toxicity exceeds the
reference toxicity and 50 percent by -a substantial margin. Some potentially
appropriate restrictions are described in paragraphs 81-93. If the local
authority desires to fully evaluate the potential for receiving water impacts
B13
-------
to occur, it will reach a DECISION FOR FURTHER EVALUATION by considering mix-
ing as discussed in paragraph B17.
B16. Commencement Bay area authorities have tentatively decided i-o make
the LAD discussed in paragraph B15 using the following quantitative approach.
This quantitation was selected for use when Cotnrnencemen: Fay area goal*
(paragraph 70) require the use of a relatively pristine reference, as is the
case in the example in Part III and Tables 3-21. Other values may be neces-
sary to achieve local goals that utilize a less pristine reference. Although
conceptually similar approaches could be taken elsewhere, the approach and its
quantitation would have to be tailored specifically to local goals. The au-
thors do not necessarily advocate either quantitation of the guidance of para-
graph B15 or its quantitation in the following manner since the guidance con-
siderations may be complexly interactive. The approach described below is the
initial approach tentatively selected 'by Commencement Bay area authorities and
should not be construed as final Commencement Bay area guidance nor as implied
guidance or a precedent for actual LADs elsewhere.
£. If the dredged material effluent produces greater toxicity
than the reference material in £G percent or less of the
test species, there is cause for low concern. If dredged
material effluent toxicity exceeds reference toxicity in
20 percent-80 percent of the test species, there is cause for
moderate concern. If" dredged material effluent toxicity ex-
ceeds reference toxicity in 80 percent or more of the test
species, there is cause for high concern.
b_. If the dredged material effluent produces toxicity 20 percent
age points* or less above the control in all test species,
there is cause for low concern. If dredged material effluent
toxicity is 20-40 percentage points* above control toxicity in
any species, there is cause for moaerate concern. If dredged
material effluent toxicity is 40 percentage points* or more
above control toxicity in any species, there is cause for
high concern.
c_. If the dredged material effluent produces toxicity in all spe-
cies less than or equal to two times the reference material
toxicity, there is cause for low concern. If dredged material
effluent toxicity in any species is 1-40 times reference tox-
icity. there is cause for moderate concern. If dredged mate-
rial effluent toxicity in any species is 40 or more times the
reference toxicity, there is cause for high concern.
*For example, if 2 of 100 control animals (2 percent) show toxicity, then
at least 12 of 100 test animals (12 percent) would have to show toxicity
in order for toxicity of the test sediment to be 10 percentage points
above the control.
B14
-------
d_. If 50 percent or less of the sediment sampling sites in the
dredging area being evaluated have effluent toxicity exceeding
the reference toxicity, there is cause for low concern. If
more than 50 percent of the sediment sampling sites in the
area being evaluated have effluent toxicity to any species ex-
ceeding the reference or criterion, there is cause for high
concern. (If a single composite sample from the dredging area
is analyzed, this factor drops from consideration.)
Findings of low concern in all factors, a_ through d_, lead to a DECISION OF NO
RESTRICTIONS required to protect against contaminant impacts in the water col-
umn. A finding of high concern in any three of the four factors leads to a
DECISION OF RESTRICTIONS required to protect against contaminant impacts in
the water column. Some potentially appropriate restrictions are described in
paragraph 81-93. All other combinations of findings lead to a DECISION FOR
FURTHER EVALUATION by considering mixing as discussed in paragraph B18.
DECISION FOR FURTHER EVALUATION; CONSIDER MIXING
B17- If the considerations of paragraph B15 lead to an evaluation of
mixing, the local authority must decide whether the size and configuration of
the mixing zone required to dilute the discharge to less than the LC50 con-
centration are acceptable. Mixing zone calculation is described in para-
graphs- 31-33 and Appendix D. Note that mixing calculations must be based on
the receiving water for the discharge, which may or may not be the reference
water. Mixing zone evaluations as discussed in paragraphs 34-36 can result
in:
a. A mixing zone of acceptable size and configuration within
~ which the effluent discharge will be diluted to less than the
LC50. Acceptability of the mixing zone is determined in light
of the considerations in paragraph 34 and paragraph B15 eval-
uated at the edge of the mixing zone. This leads to a DECI-
SION OF NO RESTRICTIONS required to protect against possible
contaminant impacts in the receiving water. (In the case of
subparagraph B14c, the LC50 is not exceeded even without con-
sideration of mixing, but if desired the mixing zone to dilute
to some lower value, such as LC20, can be calculated.)
b. A mixing zone (within which the discharge will be diluted to
~~ less than the LC50) that is of unacceptable size and/or config-
uration. Acceptability of the mixing zone is determined in
light of the considerations in paragraph 34 and paragraph B15
evaluated at the edge of the mixing zone. This leads to a
DECISION FOR RESTRICTIONS required to protect against possible
contaminant impacts in the receiving water. Some potentially
appropriate restrictions are described in paragraphs 81-93.
B15
-------
B18. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph El? using the following quantitative approach.
This quantitation was selected for use when Commencement Bay area goals
(paragraph 70) require the use of a relatively pristine references as is the
case in the example in Part III and Tables 3-22. Other values may be neces-
sary to achieve local goals that utilize a less pristine reference. Although
conceptually similar approaches could be taken elsewhere, the.approach and its
quantitation would have to be tailored specifically to local goals. The au-
thors do not necessarily advocate either quantitation of the guidance of para-
graph B17, or its quantitation in the following manner since the guidance con-
siderations may be complexly interactive. The approach described below is the
initial approach tentatively selected by Commencement Bay area authorities and
should not be construed as final Commencement Bay area guidance nor as implied
guidance or a precedent for actual LADs elsewhere.
a. A DECISION OF NO RESTRICTIONS required to protect against
possible contaminant impacts in the water column is reached
if the mixing zone is acceptable (paragraph 35) and there
is cause for low concern in any three of the, four factors
in paragraph B16 considered at the edge of the mixing zone.
_b. A DECISION OF RESTRICTIONS required to protect against pos-
sible contaminant impacts in the water column is reached if
the mixing zone is unacceptable (paragraph 35) or there is
cause for moderate or high concern in any two of the four
factors in paragraph B16 considered at the edge of the mixing
zone. Some potentially appropriate restrictions are described
in paragraphs 81-93.
Surface Runoff Quality Tests
B19. Concerns about contaminant impacts from surface runoff quality
after the upland disposal site is filled and the dredged material begins to
dry out have centered on short-term impacts in the receiving water during
rainfall events. The decision points and the tests appropriate for deter-
mining potential impacts from surface runoff water are shown in Figure B3.
This flowchart is similar to that for effluent water and the discussion of
decision points is exactly the same. Surface runoff test results should
always be compared to the quality of a reference surface water and to exist-
ing water-quality criteria. The reference surface water must be selected by
LAD and could be the receiving water into which the disposal site surface
runoff flows or it could be a surface water from another reference site. The
B16
-------
SURFACE RECEIVING
RUNOFF WATER
B19
/ X CHEMICAL
V y/ EVALUATION
WATER
DUALITY
RESTRICTIONS
WATER rREFEB'
QUALITY |
CRITERIA
I—REFER
REFERENCE- TEST-
B27
ENCE - TEST-»-J N0 RESTRICTIONS
i— TOXICITY: REFERENCED TEST LCW
-TOXICITY: REFERENCE< TEST LCBO
-TOXICITY: REFERENCE TEST LCSO
-TOXICITY: REFERENCE - TEST LCSO
-REFERENCE TEST ! CR'UHlON ' ^ T"*
.B22 AB24
UM >HH I HIM I > .1 Nil I Hi I! Hn .N
Hi f I ME NCt > TtSt > ACUM LHITtHION
NO RESTRICTIONS
Figure B3. Flowchart for decisionmaking for surface runoff water quality
(number near LAD is paragraph discussing LAD)
-------
local authority must decide whether to take a chemical or biological based
approach to evaluating the potential impacts of the surface runoff on the
receiving water. Chemical evaluations are appropriate when concern is pri-
marily with contaminants for which water-quality criteria have been estab-
lished (Table C2) and there is little concern about interactive effects of
multiple contaminants. If the concern is primarily with chemicals for which
water-quality criteria have not been established, or there is concern about
interactive effects of multiple contaminants, a biological approach is
preferred.
DECISIONS FROM SURFACE RUNOFF CHEMICAL EVALUATIONS
B20. Chemical analyses of ^he surface runoff tests are evaluated in
comparison to dissolved contaminant concentrations in an appropriate reference
water and to acute water-quality criteria for contaminants for which criteria
exist (Table C2) . Acute criteria are maximum concentrations that should not
be exceeded and are appropriate because of the transient nature of surface
runoff discharges into the receiving water. Contaminants for which criteria
exist are evaluated separately from those for which criteria have not been
established.
B21. When acute water-quality criteria exist for the contaminants of
concern, five conditions are possible (Figure B3).
a. Concentrations of all dissolved contaminants in the test sur-
face runoff are less than or equal to the reference water and
less than the acute water-quality criterion for each contam-
inant (Table C2).
b. Concentrations of any dissolved contaminant in the test is
greater than in the reference water and less than the acute
water-quality criterion (Table C2).
Conditions a and b lead to a DECISION OF NO RESTRICTIONS re-
quired to protect against degradation of the water column be-
yond existing reference site conditions.
£. Concentration of any dissolved contaminant in the test is
equal to or greater than the reference water and the reference
water is equal to or greater than the acute water-quality cri-
terion (Table C2).
d_. Concentration of any dissolved contaminant in the test is less
than or equal to the reference water and equal to or greater
than the acute water-quality criterion (Table C2). Since di-
lution to the criterion cannot occur under conditions £ and d_
(unless the receiving water for the discharge is not the ref-
erence water and is less than the criterion), this lead to a
B'8
-------
DECISION FOR RESTRICTIONS required to protect against contami-
nant impacts in the water column due to the proposed surface
runoff discharge. Some potentially appropriate restrictions
are described in paragraphs 81-92 and 94.
£. Concentrations of any dissolved contaminant in the test is
equal to or greater than the acute water-quality criterion
(Table C2) and the reference water is less than the acute
water-quality criterion. Since dilution to the criterion
can occur (if the receiving water for the discharge, which
may or may not be the reference water, is less than the cri-
terion), this leads to a LOCAL AUTHORITY DECISION as dis-
cussed in paragraph B22.
LOCAL AUTHORITY DECISION; RESTRICTIONS/NO RESTRICTIONS/CONSIDER MIXING
B22. Under the conditions of subparagraph B21e, dilution will occur
when the disposal site surface runoff enters the receiving water (if the
receiving water for the discharge, which may or may not be the reference
water, is less than the criterion). Consequently, mixing must be considered
in order to scientifically assess the potential for surface runoff discharge
impacts to occur. However, in some cases the local authority may choose to
reach a decision without considering mixing, by assessing test results in
light of the increasing concern about potential contaminant impacts from the
disposal site surface runoff discharge in direct relation to:
&. Number of contaminants (for which criteria have been estab-
lished) exceeding reference concentrations.
b^. Number of contaminants (with criteria) exceeding the acute
criteria.
c. Magnitude by which reference concentrations are exceeded.
d_. Magnitude by which criteria are exceeded.
£. Toxicological importance of contaminants exceeding reference
concentrations and/or acute criteria. Contaminants that
can be objectively ranked in this manner are presented in
Table C3.
f. Proportion of sediment sampling sites in the dredging area
~~ being evaluated which have test surface runoff exceeding ref-
erence concentrations and/or acute criteria. (If a single
composite sample from the dredging area is analyzed, this
factor drops from consideration.)
In the case of subparagraph B21e, the local authority might choose, without
considering mixing, to reach a DECISION OF NO RESTRICTIONS required to protect
against contaminant impacts in the receiving water. This~ n/ay be appropriate
if samples from only a few sites have only a small number of contaminants of
relatively low toxicological aoncern exceeding the reference by a small amount
and are well below the acute .criteria. In the case of subparagraph 21e, the
B19
-------
local authority might: also choose, without considering mixing, to reach a
DECISION FOR RESTRICTIONS required to protect against contaminant impacts in
the receiving water. This may be appropriate if samples from a number of
sites have several contaminants of relatively high toxioological concern ex-
ceeding the reference and the criteria by a substantial margin. A decision
for restrictions would be particularly appropriate in cases where the receiv-
ing water already exceeded the criterion, making dilution to the criterion
impossible. Some potentially appropriate restrictions are described in para-
graphs 81-92 and 94. If the local authority desires to fully evaluate the
potential for receiving water impacts to occur, it will reach a DECISION FOR
FURTHER EVALUATION by considering mixing as discussed in paragraph B24.
B23. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph B22 usi^.g the following quantitative approach.
This quantitation was selected for use when local goals (paragraph 70) require
the use of a relatively pristine reference, as is the case in the example in
Part III and Tables 3-21. Other values may be necessary to achieve local
goals that utilize a less pristine reference. Although conceptually similar
approaches could be taken elsewhere, the approach and its quantitation would
have to be tailored specifically to local goals. The authors do not neces-
sarily advocate either quantitation of the guidance of paragraph B22 or its
quantitation in the following manner since the guidance considerations may be
complexly interactive. The approach described below is the initial approach
tentatively selected by Commencement Bay area authorities and should not be
construed as final Commencement 3ay area guidance nor as implied guidance or a
precedent for actual LADs elsewhere.
a. Number of contaminants above reference. If 25 percent or less
of the contaminants of concern (for which criteria have been
established) exceed reference, there is cause for low concern,
If 2/3 percent-90 percent of the contaminants of concern with
criteria exceed reference, there is cause for moderate concern.
If 90 percent or more of the contaminants of concern with cri-
teria exceed reference, there is cause for high concern.
b. Number of contaminants above criteria. If 25 percent or less
of the contaminants of concern with criteria exceed the cri-
teria, there is cause for low concern. If 25-percent-75 per-
cent of the contaminants of concern with criteria exceed the
criteria, there is cause for moderate concern. If 75 percent
or more of the contaminants of concern with criteria exceed
the criteria, there is cause for high concern.
£. Magnitude above reference. If the contaminant of concern
(with a criterion) that exceeds reference by the greatest fac-
tor is less than or equal to 25 times reference concentration,
there is cause for low concern.If any contaminant of concern
(with a criterion) is 25-100 times reference concentration,
there is cause for moderate concern. If any contaminant of
concern (with a criterion) is 100 or more times reference con-
centration, there is cause for high concern.
d. Magnitude above criterion. If the contaminant of concern
(with a criterion) that exceeds its criterion by the greatest
factor is less than or equal to 10 times the criteria, there
is cause for low concern. If any contaminant of concern (with
a criterion) is 1C-'.CG times the criteria, there is cause for
B20
-------
mode.fate concern. If any contaminant of concern (with a cri-
terion) is 100 or more times the criterion, there is cause for
high concern,
e_. Toxicological importance. If all contaminants of concern
(with criteria) are rank~l or 2 in Table C3, there is cause
for low concern. If any contaminant of concern (with a cri-
terion) is rank S or 4 in Table C3, there is cause for moder-^
ate concern. If any contaminant of concern (with a criterion)
is rank 5 or 6 in Table C3, there is cause for high concern,
(Unranked contaminants of concern are cause for moderate con-
cern unless there is additional evidence to reasonably warrant
a different level of concern.)
f_. Number of sampling sites. If 50 percent or less of the sedi-
ment sampling sites in the dredging area being evaluated have
any contaminant of concern (with a criterion) exceeding the
reference or criterion, there is cause for low concern. If
more than 50 percent of the sediment sampling sites in the
area being evaluated have any contaminant of concern (with
a criterion) exceeding the reference or criterion, there is
cause for high concern, (If a single composite sample
from the dredging area is tested, this factor drops from
consideration.)
Findings of low concern in all factors, a through f_, lead to a DECISION OF NO
RESTRICTIONS required to protect against contaminant impacts from surface run-
off. A finding of high concern in any four of the six factors, a through f_,
leads to a DECISION OF RESTRICTIONS required to protect against contaminant
impacts in the water column. Some potentially appropriate restrictions are
described in paragraphs 81-92 and 94. All other combinations -of findings lead
to a DECISION FOR FURTHER EVALUATION by considering mixing as discussed in
paragraph B25.
DECISION FOR FURTHER EVALUATION; CONSIDER MIXING
B24. If the considerations of paragraph B22 lead to an evaluation of
mixing, the local authority must decide whether the size and configuration of
the mixing zone required to dilute the discharge to the water-quality criteria
are acceptable. Mixing zone calculation is described in paragraphs 31-33 and
Appendix D. Note that mixing calculations must be based on the receiving
waters for the discharge, which may or may not be the reference water. Mixing
zone evaluation as discussed in paragraphs 34-36 can result in:
a. A mixing zone of acceptable size and configuration within
which the surface runoff will be diluted to less than the
acute water-quality criterion (Table C2). Acceptability of
the mixing zone is determined in light of the considerations
in paragraph 34 and paragraph B22 evaluated at the edge of
the mixing zone. This leads to a DECISION OF NO RESTRICTIONS
B21
-------
required to protect against possible contaminant impacts in
the receiving water.
b. A mixing zone within which the surface lunoff will be diluted
to less than the acute water-quality criterion (Table C2) that
is of unacceptable size and/or configuration. Acceptability of
the mixing zone is determined in light of the considerations
in paragraph 34 and paragraph B22 evaluated at the edge of
the mixing zone. This leads to a DECISION FOR RESTRICTIONS
required to protect against possible contaminant impacts in
the receiving water. Some potentially appropriate restric-
tions are described in paragraphs 81-92 and 94.
B25. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph B24 using the following quantitative approach.
This quantitation was selected for use when Commencement Bay area goals (para-
graph 70) require the use of a relatively pristine reference, as is the case
in the example in Part III and Tables 3-21. Other values may be necessary to
achieve local goals that utilize a less pristine referer.ie. Although con-
ceptually similar approaches could be taken elsewhere, t-/e approach and its
quantitation would have to be tailored specifically t) local goals. The
authors do not necessarily advocate either quantitation ,;/ the guidance of
paragraph B24 OP its quantitation in the following mannc* since the guidance
considerations may be complexly interactive. The approach described below is
the initial approach tentatively selected by Commencement Bay area authorities
and should not be construed as final Commencement Bay ar^.a guidance nor as
implied guidance or a precedent for actual LADs elsewhere.
a. A DECISION OF NO RESTRICTIONS required to protect against
possible contaminant impacts in the water column is reached
if the mixing zone is o.cceptable (paragraph 35) and there
is cause for low concern in any four of the six factors in
paragraph B23 considered at the edge of the mixing zone.
b. A DECISION OF RESTRICTIONS required to protect against pos-
sible contaminant impacts in the water column is reached if
the mixing zone is unacceptable, (paragraph 35) or_ there is
cause for moderate or high concern in ar^ four of the six
factors in paragraph B23 considered at the edge of the mixing
zone. Some potentially appropriate restrictions are described
in paragraphs 81-92 and 94.
B26, When acute water-quality criteria do not exist for contaminants of
concern, two conditions are possible (Figure B3):
a. Concentrations of all dissolved contaminants of concern in the
test surface runoff are Less thar or equal to the reference
water. This leads to a DECISION OF NO RESTRICTIONS required
to protect against degradation of the receiving water beyond
existing reference site conditions.
B22
-------
_b_. Concentrations of any dissolved contaminant in the test sur-
face runoff is greater than in the reference water. This
leads to a LOCAL AUTHORITY DECISION.
LOCAL AUTHORITY DECISION; BIOASSAYS
B27. Under the conditions of subparagraph B26b there is no available
information for determining the environmental importance of a contaminant which
exceeds the reference concentration. This can be determined with bioassays.
However, in some cases the local authority may choose to reach a decision,
without conducting bioassays, by assessing test results in light of the
increasing concern about potential contaminant impacts in the receiving water
in direct relation to the factors listed in paragraph B22. In the case of
subparagraph B26b, the local authority might choose, without conducting bio-
assays, to reach a DECISION OF NO RESTRICTIONS required to protect against
contaminant impacts in the receiving water. This may be appropriate if samples
from only a few sites have a small number of contaminants exceeding the refer-
&•
enoe by a small amount. Since there are no criteria, if bioassays are not
considered necessary on the above basis, there is no "target concentration"
for a mixing zone calculation. However, in addition to the contaminant con-
siderations of paragraph B22, the surface runoff discharge should be subjec-
tively assessed in light of the mixing zone considerations of paragraph 34
before a DECISION OF NO RESTRICTIONS is reached. On the other hand, the local
authority might choose, without conducting bioassays, to reach a DECISION FOR
RESTRICTIONS required to protect against contaminant impacts in the receiving
water. This may be appropriate if samples from a number of sites have several
contaminants exceeding the reference by a substantial 'margin. Some potentially
appropriate restrictions are described in paragraphs 81-92 and 94. If the
local authority desires to fully evaluate the potential for receiving water
impacts to occur, it will reach a DECISION FOR FURTHER EVALUATION by conducting
bioassays as described in paragraph B29.
B28. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph B27 using the quantitative approach described
in paragraph B23. This quantitation was selected for use when Commencement
Bay area goals (paragraph 70) require the use of a relatively pristine refer-
ence, as is the case in the example in Part III and Tables 3-21. Other values
may be necessary to achieve local goals that utilize a less pristine reference.
Since there are no water-quality criteria j'or the contaminants presently under
B23
-------
consideration, factors b_ and d_ are simply excluded from consideration, and the
other factors evaluated as described in paragraph 823. If a DECISION FOR
FURTHER EVALUATION is reached, bioassays must be conducted and evaluated as
described in paragraph B29. Although conceptually similar approaches to
interpreting test results in the absence of water-quality criteria could be
taken elsewhere, the approach and its quantitation would have to be tailored
specifically to local goals. The authors do not necessarily advocate either
quantitation of the guidance of paragraph B27 or its quantitation in the above
manner since the guidance considerations may be complexly interactive. The
approach described above is the initial approach tentatively selected by Com-
mencement Bay area authorities and should not be construed .as final Commence-
ment Bay area guidance nor as implied guidance or a precedent for actual local
authority decisions elsewhere.
DECISIONS FROM SURFACE RUNOFF BIOLOGICAL EVALUATIONS
B29. From this point on, the evaluation of potential receiving water
impacts is biological. It is at this point that testing begins if a biological
approach is initially chosen in paragraph B19 (Figure B3). Surface runoff
water bioassays can result in four possible conditions:
_a. Toxicity of the test water (surface runoff) to all species
is less than or equal to the reference water and less than
the LC50 (i.e., 50-percent toxicity is not reached in the
test water). This leads to a DECISION OF NO RESTRICTIONS
required to protect against contaminant impacts in the re-
ceiving water.
_b. Toxicity of the test water to any species is less than or
equal to the reference water and equal to or greater th~an the
LC50 (i.e., at least 50-percent toxicity is reached in the test
water). This leads to a DECISION FOR RESTRICTIONS required to
protect against contaminant impacts in the receiving water.
Some potentially appropriate restrictions are described in
paragraphs 81-92 and 94.
£. Toxicity of the test water to any species is greater than the
reference water, and less than the LC50, or
d_. Toxicity of the test water to any spcies is greater than the
reference water and equal to or greater than the LC50.
(Therefore, dilution to the LC50 is possible if the receiving
water for the discharge, which may or may not be the reference
water, is less than the LC50).
Conditions £ and d_ lead to a LOCAL AUTHORITY DECISION.
LOCAL AUTHORITY DECISION: RESTRICTIONS/NO RESTRICTIONS/CONSIDER MIXING
B30. Under the conditions of subparagraph B29c or d_, dilution will occur
B24
-------
when the disposal site surface runoff enters the receiving water (if the re-
ceiving water for the discharge, which may or may not be the reference water,
is less than the LC50). Consequently, mixing must be considered in order to
scientifically assess the potential for receiving water impacts to occur.
However, in some cases the local authority may choose to reach a decision,
without considering mixing, by assessing test results in light of the in-
creasing concern about potential contaminant impacts in the receiving water
in direct relation to:
a.. Number of species bioassayed with surface runoff with toxicity
exceeding reference toxicity.
_b. Magnitude of test toxicity.
c. Magnitude by which reference toxicity is exceeded.
d_. Proportion of sediment sampling sites in the dredging area
being evaluated which have surface runoff whose toxicity
exceeds reference toxicity. (If a single composite sample
from the dredging area is bioassayed, this factor drops from
consideration.)
In the case of subparagraph B29c, the local authority may choose, without con-
sidering mixing, to reach a DECISON OF NO RESTRICTIONS required to protect
against contaminant impacts in the receiving water. This may be appropriate
if samples from only a few sites are toxic to a low number of species and the
toxicity only slightly exceeds reference toxicity and is well below 50 per-
cent. In the case of subparagraph B29d the authority may choose, without con-
sidering mixing, to reach a DECISION FOR RESTRICTIONS required to protect
against contaminant impacts in the receiving water. This may be appropriate
if samples from a number of sites are toxic to several species and the toxicity
exceeds the reference toxicity and 50 percent by a substantial margin. Some
potentially appropriate restrictions are described in paragraphs 81-92 and 94.
If the local authority desires to fully evaluate the potential for receiving
water impacts to occur, it will reach a DECISION FOR FURTHER EVALUATION by
considering mixing as discussed in paragraph B32.
B31. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph B30 using the following quantitative approach.
This quantitation was selected for use .when Commencement Bay area goals
(paragraph 70) require the use of a relatively pristine reference, as is the
case in the example in Part III and Tables 3-21. Other values may be neces-
sary to achieve local goals that utilize a less pristine reference. Although
conceptually similar approaches could be taken elsewhere3 the approach and its
B25
-------
quantisation would have to be tailored specifically to local goals. '1'he
authors do not necessarily advocate either quantitation of the guidance of
paragraph B30 or its quantitation in the following manner since the guidance
considerations may be complexly interactive. The approach described below is
the initial approach tentatively selectc ' by Commencement Bay area authorities
and should not be construed as final Commencement Bay area guidance nor as
implied guidance or a precedent for actual LADs elsewhere.
a. If the dredged material surface runoff produces greater toxic-
~ ity than the reference material in 20 percent or less of the
test species, there is cause for low concern. If dredged
material surface runoff toxicity exceeds reference toxicity
in 20 percent-80 percent of the test species, there is cause
for moaerate conceim. If dredged material surface runoff tox-
icity exceeds reference toxicity in 80 percent or more of the
test species, there is cause for high concern.
_b. If the dredged nuiterial surface runoff produces toxicity in
all test species 20 percentage points* or less above the con-
trol, there is cause for low concern.If dredged material
surface runoff toxicity in any test species is 20-40 per-
centage points* above control toxicity, there is cause for
moderate concern. If dredged material surface runoff tox-
icity in any test species is 40 percentage points* or more
above control toxicity, there is cause for hi.gh concent.
£. If the dredged material surface runoff produces toxicity in all
species less than or equal to two times the reference material
toxicity, there is cause for low concern. If dredged material
surface runoff toxicity in any species is 2-40 times reference
toxicity, there is cause for moderate concern. If dredged ma-
terial surface runoff toxicity in any species is 40 or more
times the reference toxicity, there is cause for high concern.
d_. If 50 percent or less of the sediment sampling sites in the
dredging area being evaluated have surface runoff toxicity to
any species exceeding the reference toxicity, there is cause
for low concern. If more than 50 percent of the sediment sam-
pling sites in the area being evaluated have surface runoff
toxicity to any species exceeding the reference toxicity,
there is cause for high concern.
Findings of low concern in all factors, a_ through d_, lead to a DECISION OF
NO RESTRICTIONS required to protect against contaminant impacts in the water
column. A finding of high concern in two or more factors leads to a DECISION
OF RESTRICTIONS required to protect against contaminant impacts in the water
* For example, if 2 of 100 control animals (2 percent) show toxicity; then at
least 22 of 100 test animals (22 percent) would have to show toxicity in
order for toxicity of the test sediment to be 20 percentage points above the
control.
B26
-------
column. Some potentially appropriate restrictions are described in para-
graphs 81-92 and 94. All other combinations of findings lead to a DECISICM
FOR FURTHER EVALUATION by considering mixing as discussed in paragraph B33.
DECISION FOR FURTHER EVALUATION; CONSIDER MIXING
B32. If the considerations of paragraph B30 lead to an evaluation of
mixing, the local authority must decide whether the size and configuration of
the mixing zone required to dilute the discharge to less than the LC50 con-
centration are acceptable. Mixing zone calculation is described in para-
graphs 31-33 and Appendix D. Note that mixing calculations must be based on
the receiving water for the discharge, which may or may not be the reference
Water. Mixing zone evaluations as discussed in paragraphs 34-36 can result
in:
a. A mixing zone of acceptable size and configuration within
which the surface runoff will be diluted to less than the
LC50. Acceptability of the mixing zone is determined in light
of the considerations in paragraph 34 and paragraph B30 evalu-
ated at the edge of the mixing zone. This leads to a DECISION
OF NO RESTRICTIONS required to protect against possible con-
taminant impacts in the receiving water. (In the case of sub-
paragraph B29c, the LC50 is.not exceeded even without consid-
eration of mixing, but if desired, the mixing zone to dilute
to some lower value, such as LC20, can be calculated.)
b. A mixing zone (within which the surface runoff will be diluted
~~ to less than the LC50) that is of unacceptable size and/or
configuration. Acceptability of the mixing zone is deter-
mined in light of the considerations in paragraph 34 and
paragraph B30 evaluated at the edge of the mixing zone.
This leads to a DECISION FOR RESTRICTIONS required to pro-
tect against possible contaminant impacts in the receiving
water. Some potentially appropriate restrictions are de-
scribed in paragraphs 81-92 and 94.
B33. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph B21 using the following quantitative approach.
This quantitation was selected for use when Commencement Bay area goals
(paragraph 70) require the use of a relatively pristine reference, as is the
case in the example in Part III and Tables 2-21. Other values may be neces-
sary to achieve local goals that utilize a less pristine reference. Although
conceptually similar approaches could be taken elsewhere, the approach and its
quantitation would have to be tailored specifically to local goals. The
authors do not necessarily advocate either quantitation of the guidance of
paragraph B31 or its quantitation in the following manner since the guidance
B27
-------
considerations mat/ be complexly interactive. The approach described below is
the initial approach tentatively selected by Commencement Bay area authorities
and should not be cone trued as final Commencement Bay area guidance nor as
implied guidance or a precedent for actual LADs elsewhere.
a_. A DECISION OF NO RESTRICTIONS required to protect against pos-
sible contaminant impacts in the water column is reached if
the mixing zone is.acceptable (paragraph 35) and there is
cause for low concern in any three of the four factors in
paragraph B31 considered at the edge of the mixing zone.
_b. A DECISION OF RESTRICTIONS required to protect against pos-
sible contaminant impales in the water column is reached if
the mixing zone is unacceptable (paragraph 35) or there is
cause for moderate or high concern in any two of the four
factors in paragraph B31 considered at the edge of the mixing
zone. Some potentially appropriate restrictions are described
in paragraphs 81-92 and 94.
Leachate Quality Tests
B34. Leachate quality tests will indicate the potential of contaminants
to move through and from a dredged material. Leachate quality evaluation has
been divided into three parts: impact of seepage through a dike into a receiv-
ing water body (Figure B4), a impact of leachate on drinking water (Figure B4),
and impact on nonpotable ground water (Figure B5). Test results should always
be compared to the quality of an appropriate reference water. The local au-
thority must select a reference surface water such as the receiving water ad-
jacent to the disposal site or another reference (background) surface water.
Water-quality criteria (Table C2) should be used to compare leachate test re-
sults to make a decision on relative biological impacts. In addition, the
local authority must select a reference ground water such as the ground water
under the disposal site or another reference (background) to compare to leach-
ate test results. Drinking water-quality standards (Table C4) should be used
to compare leachate test results to make a decision on relative human health
effects. If drinking water-quality standards do not exist, then leachate test
results are compared to the appropriate reference water. The selection of
each of these reference waters by the Commence Bay area authorities is gov-
erned by the overall goal established by the local authority for the area as
discussed in paragraph 70.
B28
-------
LEACHATE SEEPAGE INTO A RECEIVING WATER BODY
B35. The local authority must decide whether to take a chemical or
biological based approach to evaluating the potential impacts of the leachate
seepage on the receiving water. Chemical evaluations are appropriate when
concern is primarily with contaminants for which water-quality criteria have
been established (Table C2) and there is little concern about interactive
effects of multiple contaminants. If the concern is primarily with chemicals
for which water-quality criteria have not been established or if there is con-
cern about interactive effects of multiple contaminants, a biological approach
is preferred.
DECISIONS. FROM LEACHATE SEEPAGE CHEMICAL EVALUATIONS
B36. Chemical analyses of the leachate are evaluated in comparison to
dissolved contaminant concentrations in a reference water and to chronic
water-quality criteria for contaminants for which criteria exist (Table C2).
The 24-hr average water concentration should not exceed the chronic criterion.
Chronic criteria are appropriate because of the long-term nature of leachate
seepage into the receiving water. Contaminants for which criteria exist are
evaluated separately from those for which criteria have not been established.
B37. When chronic water quality criteria exist for the contaminants of
concern, five conditions are possible (Figure B4).
_a. Concentrations of all dissolved contaminants in the test
leachate are less than or equal to the reference water and
less than the chronic water-quality criterion for each contam-
inant (Table C2).
b. Concentration of any dissolved contaminant in the test is
~~ greater than in the reference water and less than the chronic
water-quality criterion (Table C2).
Conditions a. and b^ lead to a DECISION OF NO RESTRICTIONS
required to protect against degradation of the water column
beyond existing reference site conditions.
c. Concentrations of any dissolved contaminant in the test is
equal to or greater than the reference water, and the refer-
ence water is equal to or greater than the chronic water-
quality criterion (Table C2).
d_. Concentration of any dissolved contaminant in the test is less
than or equal to the reference water and equal to or greater
than the chronic water-quality criterion (Table C2). Since
dilution to the criterion cannot occur under conditions £ and
d_ (unless the receiving water for the discharge is not the
reference water and is loss than the criterion), they lead to
B29
-------
Ul
o
f ACMATt Hj^CEIVING
•'OAUTV WATER
B35
CHEMICAL
EVALUATION
NO
WATFR
QUALITY
CRITERIA
REFERENCE- TEST
REFERENCE TSST-»-| NO RESTRICTIONS
— TOXICITV: REFFRFNCt ^ TEST LC5Q
— TOXICITY: REFERENCE- TEST LCSO
-TOXICITY: REFERENCE TEST LCBO
-TOXICITY: REFERENCE . TEST LCSO
NO RESTRICTIONS
Y
RESTRICTIONS
r .» Ht » I HI M I > 'I Si < i.HHONIt CHi1bHli'\—|
I »• NUHfSTHiC IIDNS
-^—(11 M I'I M.t * HSI C < MHONlC CHlTl HnJN —* S p
WATER
QUALITY
Figure B4. Flowchart for decisionmaking for leachate seepage quality impact
to receiving water (number near LAD is paragraph discussing LAD)
-------
a DECISION FOR RESTRICTIONS required to protect against con-
taminant impacts in the water column due to leachate from the
proposed discharge. Some potentially appropriate restrictions
are described in paragraphs 81-92 and 95.
e_. Concentrations of any dissolved contaminant in the test is
equal to or greater than the chronic water-quality criterion
(Table C2). and the reference water is less than the chronic
water-quality criterion. Since dilution to the criterion can
occur (if the receiving water for the discharge, which may or
may not be the reference water, is less than the criterion),
this leads to a LOCAL AUTHORITY DECISION as discussed in
paragraph B38.
LOCAL AUTHORITY DECISION; RESTRICTIONS/NO RESTRICTIONS/CONSIDER MIXING
B38. Under the conditions of subparagraph B37e, dilution will occur
when the disposal site leachate enters the receiving water (if the receiving
water for the discharge, which may or may not be the reference water, is less
than the criterion). Consequently, mixing must be considered in order to
scientifically assess the potential for leachate impacts to occur. However,
in some cases the local authority may choose to reach a decision, without
considering mixing, by assessing test results in light of the increasing con-
cern about potential contaminant impacts from the disposal site leachate in
direct relation to:
a_. Number of contaminants (for which criteria have been estab-
lished) exceeding reference concentration.
b. Number of contaminants (with criteria) exceeding chronic
criteria.
c. Magnitude by which reference concentrations and/or chronic
criteria are exceeded.
d. Magnitude by which criteria are exceeded.
e. Toxicological importance of contaminants exceeding reference
concentrations and/or chronic criteria. Contaminants that
can be objectively ranked in this manner are presented in
Table C3.
f. Proportion of sediment sampling sites in the dredging area
being evaluated that have test leachate exceeding reference
concentrations and/or chronic criteria. (If a single com-
posite sample from the dredging area is analyzed, this factor
drops from consideration.)
In the case of subparagraph B37e, the local authority might choose, without
considering mixing, to reach a DECISION OF NO RESTRICTIONS required to protect
against contaminant impacts in the receiving water. This may be appropriate
if samples from only a few sites have only a small number of contaminants of
B31
-------
relatively low toxicologicai concern exceeding the reference by a small amount
and are well below the chronic criteria. In the case of subparagraph B37e,
the local authority might also choose, without considering mixing, to reach a
DECISION FOR RESTRICTIONS required to protect against contaminant impacts in
the receiving water. This may be appropriate if samples from a number of
sites have several contaminants of relatively high toxicologicai concern ex-
ceeding the reference and the criteria by a substantial margin. A DECISION
FOR RESTRICTIONS would be particularly appropriate in cases where the receiv-
ing water already exceeded the criterion, making dilution to the criterion
impossible. Some potentially appropriate restrictions are described in para-
graphs 81-92 and 95. If the local authority desires to fully evaluate the
potential for receiving water impacts to occur, it will reach a DECISION FOR
FURTHER EVALUATION by considering mixing as discussed in paragraph B40.
B39. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph B38 using the following quantitative approach.
This quantitation was selected for use when Commencement Bay area goals
(paragraph 70) require the use of a relatively pristine reference, as is the
case in the example in Part III and Tables 3-21. Other values may be neces-
sary to achieve local goals that utilize a less pristine reference. Although
conceptually similar approaches could be taken elsewhere, the approach and its
quantitation would have to be tailored specifically to local goals. The au-
thors do not necessarily advocate either quantitation of the guidance of para-
graph B38S or its quantitation in the following manner since the guidance con-
siderations may be complexly interactive. The approach described below is the
initial approach tentatively selected by Commencement Bay area authorities and
should not be construed as final Commencement Bay area guidance nor as implied
guidance or a precedent for actual LADs elsewhere.
a_. Number of contaminants above reference. If 25 percent or less
of the contaminants of concern (for which criteria have been
established) exceed reference, there is cause for low concern.
If 25 percent-90 percent of the contaminants of concern with
criteria exceed reference, there is cause for moderate concern.
If 90 percent or more of the contaminants of concern with cri-
teria exceed reference, there is cause for high concern.
_b. Number of contaminants above criteria. If 25 percent or
less of the contaminants of concern with criteria exceed the
criteria, there is cause for low concern. If ££ percent -
B32
-------
75 percent of the contaminants of concern with criteria exceed
the criteria, there is cause for moderate concern. If 73 per-
cent or more of the contaminants of concern with criteria ex-
ceed the criteria, there is cause for high concern.
c_. Magnitude above reference. If the contaminant of concern
(with a criterion) present in the highest concentration is
less than, or equal to 25 times reference concentration, there
is cause for low concern.If any contaminant of concern (with
a criterion) is 2,5-100 times reference concentration, there is
cause for moderate concern. If any contaminant of concern
(with a criterion) is 100 or more times reference concentra-
tion, there is cause for high concern.
d_. Magnitude above criterion. If the contaminant of concern
(with a criterion) present in the highest concentration is
less than or equal to 10 times the criteria, there is cause
for low concern.If any contaminant of concern (with a c^i-
terion) is 10-100 times the criteria, there is cause for mod-
erate concern. If any contaminant of concern (with a crite-
rion) is 100 or more times the criterion, there is cause for
high concern.
e_. lexicological importance. If all contaminants of concern
(with criteria) are rank 1 or 2 in Table C3, there is cause
for low concern. If any contaminant of concern (with a
criterion) is rank 3 or 4 in Table C3, there is cause for
moderate concern. If any contaminant of concern (with a cri-
terion) is rank ~5 or 6 in Table C3, there is cause for high
concern. (Unranked contaminants of concern are cause for
moderate concern unless there is additional evidence to re-
asonably warrant a different level of concern.)
_f. Number of sampling sites. If 50 percent or less of the sedi-
ment sampling sites in the dredging area being evaluated have
any contaminant of concern (with a criterion) in the leachate
exceeding the reference or criterion, there is cause for low
concern. If more than 50 percent of the sediment sampling
sites in the area being evaluated have any contaminant of con-
cern (with a criterion) in the leachate exceeding the refer-
ence or criterion, there is cause for high concern. (If a
single composite sample from the dredging area is analyzed,
this factor drops from consideration.)
Findings of low concern in all factors, a_ through £_, lead to a DECISION OF NO
RESTRICTIONS required to protect against contaminant impacts in the water col-
umn. A finding of high concern in any four of the six factors, a_ through f_t
leads to a DECISION OF RESTRICTIONS required to protect against contaminant
impacts in the water column. Some potentially appropriate restrictions are
described in paragraphs 81-92 and 95. All other combinations of findings lead
to a DECISION FOR FURTHER EVALUATION by considering mixing as discussed in
paragraph B40.
B33
-------
DECISION FOR FURTHER EVALUATION: CONSIDER MIXING
B4G. If the considerations of paragraph B38 lead to an evaluation of
mixing, the local authority must decide whether the size and configuration of
the mixing zone required to dilute the discharge to the water-quality criteria
are acceptable. Mixing zone calculation is described in paragraphs 31-33 and
Appendix D. Note that mixing calculations must be based on the receiving water
for the discharge, which may or may not be the reference water. Mixing zone
evaluation as discussed in paragraphs 34-36 can result in:
£. A mixing zone of acceptable size and configuration within
which the discharge will be diluted to less than the chronic
water quality criterion (Table C2). Acceptability of the mix-
ing zone is determined in light of the considerations in para-
graph 35 and paragraph B38 evaluated at the edge of the mixing
zone. This leads to a DECISION OF NO RESTRICTIONS required to
protect against possible contaminant impacts in the receiving
water.
b_. A mixing zone within which the discharge will be diluted to
less than the chronic water-quality criterion (Table C2) that
is of unacceptable size and/or configuration. Acceptability
of the mixing zone is determined in light of the considerations
in paragraph 35 and paragraph B38 evaluated at the edge of the
mixing zone. This leads to a DECISION OF RESTRICTIONS re-
quired to protect against possible contaminant impacts in the
receiving water. Some potentially appropriate restrictions
are described in paragraphs 81-92 and 95.
B41. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph B40 using the following quantitative approach.
This quantitation was selected for use when Commencement Bay area goals (para-
graph 70) require the use of a relatively pristine reference, as is the case
in the example in Part III and Tables 3-21. Other values may be necessary to
•achieve local goals that utilise a less pristine reference. Although con-
ceptually similar approaches could be taken elsewhere, the approach and its
quantitation would have to be tailored specifically to local goals. The au-
thors do not necessarily advocate either quantitation of the guidance of para-
graph B40 or its quantitation in the following manner since the guidance con-
siderations may be complexly interactive. The approach described below is the
initial approach tentatively selected by Commencement bay area authorities and
should not be construed as final Commencement Bay area guidance nor as implied
guidance or a precedent for actual LADs elsewhere.
a. A DECISION OF NO RESTRICTIONS required to protect against pos-
sible contaminant impacts in the water column is reached if
B34
-------
the mixing zone is acceptable (paragraph 35) and there is
cause for low concern in any four of the six factors in para-
graph B39 considered at the edge of the mixing zone.
b. A DECISION OF RESTRICTIONS required to protect against pos-
sible contaminant impacts in the water column is reached if
the mixing zone is unacceptable (paragraph 35) or_ there is
cause for moderate or high concern in any four of the six
factors in paragraph B39 considered at the edge of the mixing
zone. Some potentially appropriate restrictions are described
in paragraphs 81-92 and 94.
B42. When chronic water quality criteria do not exist for contaminants
of concern, two conditions are possible (Figure B4):
a. Concentrations of all dissolved contaminants of concern in the
test leachate are less than or equal to the receiving water
(or reference water). This leads to a DECISION OF NO RESTRIC
TIONS required to protect against degradation of the receiving
water beyond existing reference site conditions.
b. Concentrations of any dissolved contaminant in the test
leachate is greater than in the receiving water (or reference
water). This leads to a LOCAL AUTHORITY DECISION.
LOCAL AUTHORITY DECISION; RESTRICTIONS/NO RESTRICTIONS/CONSIDER BIOASSAYS
B43. Under the conditions of subparagraph B42b, there is no available
information for determining the environmental importance of a contaminant
that exceeds the reference concentration. This can be determined with bio-
assays. However, in some cases the local authority may choose to reach a de-
cision, without conducting bioassays, by assessing test results in light of
the increasing concern about potential contaminant impacts in the recieving
water in direct relation to the factors listed in paragraph B38. In the case
of subparagraph B42b, the local authority might also choose, without conduct-
ing bioassays, to reach a DECISION OF NO RESTRICTIONS required to protect
against contaminant impacts in the receiving water. This may be appropriate
if samples from only a few sites have a small number of contaminants exceeding
the reference by a small amount. Since there are no criteria, if bioassays
are not considered necessary on the above basis, there is no "target concen-
tration" for a mixing zone calculation. However, in addition to the contami-
nant considerations of paragraph B38, the leachate seepage should be subjec-
tively assessed in light of the mixing zone considerations of paragraph 34
before a decision of no restrictions is reached. On the other hand, the local
authority might choose, without conducting bioassays, to reach a DECISION FOR
RESTRICTIONS required to protect against contaminant impacts in the receiving
B35
-------
water. This may be appropriate if samples from a number of sites have several
contaminants exceeding the reference by a substantial margin. Some poten-
tially appropriate restrictions are described in paragraphs 81-92 and 95. If
the local authority desires to fully evaluate the potential for receiving
water impacts to occur, it will reach a DECISION FOR FURTHER EVALUATION by
conducting bioassays as described in paragraph B45.
B44. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph B43 using the quantitative approach described
in paragraph B39. This quantitation Wad selected for use when Commencement
Bay area goals (paragraph 70) require the use of a relatively pristine refer-
ence 3 as is the- case in the .example in Part III and Tabus 3-21. Other values
may be necessary to achieve Iccal goals that utilise a less pristine reference.
Since there are no water-quality criteria for the contaminants presently under
consideration, factors b_ and d are simply excluded from consideration, and the
other factors evaluated as described in paragraph B39. ~f a DECISION FOR
FURTHER EVALUATION is reached, bioassays must be conducted and evaluated as
described in paragraph B45. Although conceptually similar approaches to
interpreting test results in the absence of water-quality criteria could be
taken elsewhere, the approach and its quantitation would have to be tailored
specifically to local goals. The authors do not necessarily advocate either
quantitation of the guidance of paragraph B43 or its quantitation in the above
manner since the guidance considerations may be complexly interactive. The
approach described above is the initial approach tentatively selected by
Commencement Bay area authorities and should not be construed as final
Commencement Bay area guidance nor as implied guidance or a precedent for
actual LADs elsewhere.
DECISIONS FROM LEACHATE BIOLOGICAL EVALUATIONS
B45. From this point on, the evaluation of potential receiving water
impacts is biological. It is at this point that testing begins if a biolog-
ical approach is initially chosen in paragraph B35 (Figure B4). Leachate
bioassays can result in four possible conditions:
a. Toxicity of the test water (leachate) to all species is less
than or equal to the reference water (receiving water) and
less than the LC50 (i.e., 50-percent toxicity is not reached in
the test water). This leads to a DECISION OF NO RESTRICTIONS
required to protect against contaminant impacts in the receiv-
ing water.
B36
-------
b_. Toxicity of the test water to any_ opecles is leas than or
equal to the reference water and equal to or greater.than the
LC50 (i.e., at least 50-percent toxicity is reached in the test
water). This leads to a DECISION FOR RESTRICTIONS required to
protect against contaminant impacts in the receiving water.
Some potential appropriate restrictions are described in para-
graphs 81-92 and 95.
£. Toxicity of the test water to any species is greater tliutn the
reference water and less than the LC50, or
d_. Toxicity of the test water to any spcies is greater than
the reference water and equal to or greater than the LC50.
(Therefore, dilution to the LC50 is possible if the receiv-
ing water for the discharge, which may or may not be the
reference water, is less than the LC50.)
Conditions £ and d_ lead to a LOCAL AUTHORITY DECISION.
LOCAL AUTHORITY DECISION: RESTRICTIONS/NO RESTRICTIONS/CONSIDER MIXING
B46. Under the conditions of subparagraph B45c or d, dilution will
occur when the disposal site effluent discharge enters the receiving water (if
the. receiving water for the discharge, which may or may not be the reference
water, is less than the LC50). Consequently, mixing must be considered in
order to scientifically assess the potential for receiving water impacts to
occur. However, in some cases the local authority may choose to reach a de-
cision, without considering mixing, by assessing test results in light of
the increasing concern about potential contaminant impacts in the receiving
water in direct relation to:
a_. Number of species bioassayed with the leachate with toxicity
exceeding reference toxicity.
_b. Magnitude of test toxicity.
c. Magnitude by which reference toxicity is exceeded.
d. Proportion of sediment sampling sites in the dredging area be-
ing evaluated that have leachate whose toxicity exceeds refer-
ence toxicity. (If a single composite sample from the dredging
area is analyzed, this factor drops from consideration.)
In the case of subparagraph B45c the local authority may choose, without con-
sidering mixing, to reach a DECISION OF NO RESTRICTIONS required to protect
against contaminant impacts in the receiving water. This may be appropriate
if samples from only a few -sites are toxic to a low number of species and the
toxicity only slightly exceeds reference toxicity -and is well below 50 percent.
In the case, of subparagraph B45d, the authority may choose, without considering
mixing, to reach a DECISION FOR RESTRICTIONS required to protect against
B37
-------
contaminant impacts in the receiving water. This r>ay bs appropriate if samples
from u. number of sii^s arc toxic to several species an^. the toxicity exceeds
the reference toxicity ar.d 50 percent by a substantial margin. Some poten-
tially appropriate restrictions are described in paragraphs 81-92 and 95. If
the local authority desires to fully evaluate the potential for receiving water
impacts to occur, it will reach a DECISION FOR FURTHER EVALUATION by consid-
ering mixing as discussed in paragraph B48.
B47. Commencement Bay area authorities have tentatively decided tv make
the LAD discussed in paragraph B46 usir,g the following quantitative a^vi'^avJi.
This quantitation was selected for use when Coiimen^in^nt bay area goals (pai-u-
graph 70) require the use of a relatively pristine reference, as is the cave
in the example in Part III and Tables 3-21. Other values may be necessary to
achieve local goals that utilize a less pristine reference. Although con-
ceptually similar approaches could be taken elsewhere, the approach and its
quantitation would have to be tailored specifically to local goals. The
authors do not necessarily aavocate either quantitation of the guidance of
paragraph B46 or its quantitation in the following manner since the guidance
considerations may be complexly interactive. The approach described below is
the initial approach tentatively selected by Commencement Bay area authorities
and should not be construed as final Commencement Bay area guidance nor as
implied guidance or a precedent for actual IADs elsewhere.
a. If the dredged material leachate produces greater toxicity
than the reference material in 20 percent or less of the test
species, there is cause for low concern. If dredged material
leachate toxicity exceeds reference toxicity in JO percent-
80 percent of the test species, there is cause for moaerate
concern. If dredged material leachate toxicity exceeds ref-
erence toxicity in 80 percent or more of the test species,
there is cause for high concern.
b. If the dredged material leachate produces toxicity in all test
species 20 percentage points* or les^ above the control, there
is cause for low concern. If dredged material leachate toxic-
ity in any test species is 110-40 percentage points* above con-
trol toxicity, there is cause for moderate concern' If
dredged material leachate toxicity in any test species is
40 percentage points* or more above control toxicity, there
is cause for high concern.
* For example, if 2 of 100 control animals (2 percent) show toxicity. then
at least 12 of 100 test animals (12 percent would have to show toxicity in
order for toxicity of the test sediment to b*1 10 percentage points above
the control.
B38
-------
c. If the dredged material leachate produces toxlcity in all spe-
cies less than or equal to two times the reference material
toxicity, there is cause for low concern. If dredged material
leachate toxicity in any species is 2-40 times reference tox-
icity, there is cause for moderate concern. If dredged mate-
rial leachate toxicity in any species is 40 or more times the
reference toxicity, there is cause for high concern.
d. If 50 percent or less of the sediment sampling sites in the
dredging area being evaluated have leachate toxicity exceeding
the reference toxicity, there is cause for low concern. If
more than 50 percent of the sediment sampling sites in the
area being evaluated have leachate toxicity exceeding the ref-
erence toxicity, there is cause for high concern.
Findings of low concern in all factors, a through d, lead to a DECISION OF NO
RESTRICTIONS required to protect against contaminant impacts in the water col-
umn. A finding of high concern in any three of the four factors leads to a
DECISION OF RESTRICTIONS required to protect against contaminant impacts in
the water column. Some potentially appropriate restrictions are described
in paragraphs 81-92 and 95. All other combinations of findings lead to a
DECISION FOR FURTHER EVALUATION by considering mixing as discussed in para-
graph B49.
DECISION FOR FURTHER EVALUATION; CONSIDER MIXING
B48. If the consideration of paragraph B46 lead to an evaluation of
mixing, the local authority must decide whether the size and configuration of
the mixing zone required to dilute the discharge to less than the LC50 con-
centration are acceptable. Mixing zone calculation is described in para-
graphs 31-33 and Appendix D. Note that mixing calculations must be based on
the receiving water for the. discharge^ which may or may not be the reference
water. Mixing zone evaluations as discussed in paragraphs 34-36 can result
in:
a. A mixing zone of acceptable size and configuration within
~ which the leachate will be diluted to less than the LC50. Ac-
ceptability of the mixing zone is determined in light of the
considerations in paragraph 34 and paragraph B46 evaluated at
the edge of the mixing zone. This leads to a DECISION OF NO
RESTRICTIONS required to protect against possible contaminant
impacts in the receiving water. (In the case of subpara-
graph B45c, the LC50 is not exceeded even without considera-
tion of mixing, but if desired, the mixing zone to dilute to
some lower value, such as LC20, can be calculated.)
b. A mixing zone (within which the leachate will be diluted to
less than the LC50) that is of unacceptable size and/or con-
figuration. Acceptability of the mixing zone is determined in
B39
-------
light of the considerations in paragraph 34 and paragraph B46
evaluated at the edge of the mixing zone. This leads to a
DECISION FOR RESTRICTIONS required to protect against possible
contaminant impacts in the receiving water. Some potentially
appropriate restrictions are described in paragraphs 81-92
and 95.
B49. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph B48 using the following quantitative approach.
This quantitation was selected for use when Commencement Bay area goals (para-
graph 70) required the use of a relatively pristine reference, as is the case
in the example in Part III and Tables 2-21. Other values may be necessary to
achieve local goals that utilize a less pristine reference. Although con-
ceptually similar approaches could be taken elsewhere, the approach and its
quantitation would have to be tailored specifically to local goals. The au-
thors do not necessarily advocate either quantitation of the guidance of para-
graph B48 or its quantitation in the following manner since the guidance con-
siderations may be complexly interactive. The approach described below is the
initial approach tentatively selected by Commencement Bay area authorities and
should not be construed as final Commencement Bay area guidance nor as implied
guidance or a precedent for actual LADs elsewhere.
a. A DECISION OF NO RESTRICTIONS required to protect against
possible contaminant impacts in the water column is reached
if the mixing zone is acceptable (paragraph 35) and there is
cause for low concern in any three of the four factors in
paragraph B47 considered at the edge of the mixing zone.
b. A DECISION OF RESTRICTIONS required to protect against pos-
sible contaminant impacts in the water column is reached if
the mixing zone is unacceptable (paragraph 35) or_ there is
cause for moderate or high concern in any two of the four
factors in paragraph B47 considered at the edge of the mix-
ing zone. Some potentially appropriate restrictions are de-
scribed in paragraphs 81-92 and 95.
DECISIONS FOR LEACHATE INTO DRINKING WATER
B50. When drinking water standards do not exist for contaminants of
concern, two conditions are possible (Figure B5):
a. Leachate concentrations of all contaminants are less than or
equal to the reference ground water. This leads to a DECISION
OF NO RESTRICTIONS required to protect against degradation of
the ground water beyond existing reference ground-water
conditions.
b. Leachate concentrations of any contaminant are greater than
~ the reference ground water. This leads to a DECISION FOR
B40
-------
zee
g
LEACHATE
QUALITY '
E
Ul |U
i
NO DRINKING
WATER
QUALITY
STANDARD
EFERENCE>TEST-
1 » REFERENCE < TEST-
DRINKING
WATER
QUALITY
STANDARD
1EFERENCE > TEST < STANDARDS-
EFERENCE < TEST < STANDARDS-
EFERENCE > TEST > STANDARDS-
-REFERENCE < TEST > STANDARDS-
REFERENCE > TEST-
NO RESTRICTIONS
REFERENCE < TEST-
RESTRICTIONS
NO RESTRICTIONS
•—I RESTRICTIONS
»—I NO RESTRICTIONS
B52
:LAD> »—WATER COLUMN
BIOASSAY
FIGURE A1
RESTRICTIONS
•—I RESTRICTIONS
WATER COLUMN
BIOASSAY
FIGURE A1
Figure B5. Flowchart for decisionmaking for leachate impacts to drinking water or nonpotable
ground water (number near LAD is paragraph discussing LAD)
-------
RESTRICTIONS required to protect against contaminant impact
in the ground water due to the proposed leachate. Some
potentially appropriate restrictions are described in para-
graphs 81-92 and 95.
B51. When drinking water standards exist, four test results are possi-
ble (Figure B5):
a. Leachate concentrations of all contaminants are less than or
equal to the reference ground water and less than the drinking
water standard (Table C4). This leads to a DECISION OF NO RE-
STRICTIONS required to protect against degradation of ground
water beyond existing reference ground water.
b_. Leachate concentrations of any contaminant is less than or
equal to the reference ground water and equal to or greater
than the drinking water standard (Table C4). This leads to
a DECISION FOR RESTRICTIONS required to protect against degra-
dation of ground water beyond existing reference ground water.
Some potentially appropriate restrictions are described in
paragraphs 81-92 and 95.
£. Leachate concentrations of any contaminant is greater than the
reference ground water and equal to or greater than the drink-
ing water standard (Table C4). This leads to a DECISION FOR
RESTRICTIONS required to protect against degradation of
ground water beyond existing reference ground water. Some
potentially appropriate restrictions are described in para-
graphs 82-91 and 95.
el. Leachate concentrations of any contaminant is greater than
reference ground water and less than the drinking water stan-
dard (Table C4). This leads to a LOCAL AUTHORITY DECISION.
LOCAL AUTHORITY DECISION; RESTRICTIONS/NO RESTRICTIONS
B52. Under the conditions of subparagraph B51d, the reference ground
water selected may be of exceptional high quality and contain extremely low
concentrations of contaminants, substantially below drinking water standards.
The local authority may choose to assess test results in light of the increas-
ing concern about potential contaminant impacts to ground water beyond existing
reference ground water in relation to:
a. Number of contaminants exceeding reference ground-water
concentrations.
b. Magnitude by which reference ground-water concentrations are
exceeded.
£. Toxicological importance of contaminants exceeding reference
ground-water concentrations. Contaminants that can be ob-
jectively ranked in this manner are presented in Table C3.
d. Proportion of sediment sampling sites in the area being
evaluated that have test leachates exceeding reference
ground-water concentrations. (If a single composite sample
B42
-------
from the dredging area is analyzed, this factor drops from
consideration.)
The local authority might choose to reach a DECISION OF NO RESTRICTIONS re-
quired to protect against contaminant impacts in the ground water. This may
be appropriate if samples from only a few sites have only a small number of
contaminants of relatively low toxicological concern exceeding the reference
by a small amount and are well below drinking water standards. In contrast,
the local authority might choose to reach a DECISION FOR RESTRICTIONS required
to protect against contaminant impacts in the ground water. This may be ap-
propriate if samples from a number of sites have several contaminants of rela-
tively high toxicological concern exceeding the reference ground water and
approaching the drinking water standards. Some potentially appropriate re-
strictions are described in paragraphs 81-92 and 95.
B53. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph B52 using the following quantitative approach.
This quantitation was selected for use when Commencement Bay area goals
(paragraph 70) require the use of a relatively pristine reference, as is the
case in the example in Part III and Tables 3-21. Other values may be
necessary to achieve local goals that utilize a less pristine reference. Al-
though conceptually similar approaches could be taken elsewhere, the approach
and its quantitation would have to be tailored specifically to local goals.
The authors do not necessarily advocate either quantitation of the guidance of
paragraph B52 or its quantitation in the following manner since the guidance
considerations may be complexly interactive. The approach described below is
the initial approach tentatively selected by Commencement Bay authorities and
should not be construed as final Commencement Bay guidance nor as implied
guidance or a precedent for actual LADs elsewhere.
a. Number of contaminants above reference. If 25 percent or less
of the contaminants of concern (for which standards have been
established) exceed reference, there is cause for low concern.
If 25 percent-90 percent of the contaminants of concern with
standards exceed reference, there is cause for moderate con-
cern. If 90 percent or more of the contaminants of concern
with standards exceed reference, there is cause for high
concern.
b. Number of contaminants above standards. If 25 percent or
less of the contaminants of concern with standards exceed the
standards, there is cause for low concern. If 25 percent-
75 percent of the contaminants of concern with standards ex-
ceed the standards, there is cause for moderate concern. If
B43
-------
75 percent or more of the contaminants of concern with stan-
dards exceed the standards, there is cause for high concern,
£. Magnitude above reference. If the contaminant of concern
(with a standard) present in the highest concentration is less
than or equal to 25 times reference concentration, there is
cause for low concern.If any contaminant of concern (with a
standard) is 25-100 times reference concentration, there is
cause for moderate concern. If any contaminant of concern
(with a standard) is 100 or more times reference concentra-
tion, there is cause for high concern!
d. Magnitude above standard. If the contaminant of concern (with
a standard) present in the highest concentration is less than
or equal to 10 times the standards, there is cause for low
concern. If any contaminant of concern (with a standard) is
10-100 times the standards, there is cause for moderate con-
cern. If any contaminant of concern (with a standard) is
100 or more times the standard, there is cause for high
concern.
£. Toxicological importance. If all contaminants of concern
(with standards) are rank 1 or 2 in Table C3, there is cause
for low concern. If any contaminant of concern (with a stan-
dard) is rank 3 or 4 in Table C3, there is cause for moderate
concern. If any contaminant of concern (with a standard) is
rank 5 or 6 in Table C3, there is cause for high concern.
(Unranked contaminants of concern are cause for moderate
concern unless there is additional evidence to reasonably war-
rant a different level of concern.)
f_. Number of sampling sites. If SO percent or less of the sedi-
ment sampling sites in the dredging area being evaluated have
any contaminant of concern (with a standard) in the leachate
exceeding the reference or standard, there is cause for low
concern. If more than 50 percent of the sediment sampling
sites in the area being evaluated have any contaminant of
concern (with a standard) in the leachate exceeding the ref-
erence or standard, there is cause for high concern. (If a
single composite sample from the dredging area is analyzed,
this factor drops from consideration.)
Findings of low concern in all factors, a through f_, lead to a DECISION OF NO
RESTRICTIONS required to protect against contaminant impacts in the ground
water. A finding of moderate or high concern in four or more factors, leads
to a DECISION OF RESTRICTIONS required to protect against contaminant impacts
in the ground water. Some potentially appropriate restrictions are described
in paragraphs 81-92 and 95. All other combinations of findings lead to a
DECISION FOR FURTHER EVALUATION by considering a water column bioassay as
discussed in paragraph B57-
B44
-------
DECISIONS FOR LEACHATE INTO NONPOTABLE GROUND WATER
B54. Leachate test results should be compared to an appropriate refer-
ence ground water. Tests can result in:
a. Leachate concentrations of all contaminants are less than or
equal to the reference ground water. This leads to a DECISION
OF NO RESTRICTIONS required to protect against degradation of
the ground water beyond existing reference ground-water
conditions.
b. Leachate concentrations of any contaminants are greater than
the reference ground water. This leads to a LOCAL AUTHORITY
DECISION.
LOCAL AUTHORITY DECISION; RESTRICTIONS/NO RESTRICTIONS/CONSIDER BIOASSAYS
B55. Under the conditions of subparagraph B54b, the local authority may
choose to assess test results in light of the increasing concern about poten-
tial contaminant impacts to ground water beyond existing reference ground water
in relation to:
a. Number of contaminants exceeding reference ground water.
b. Magnitude by which reference ground-water concentrations are
exceeded.
£. Toxicological Importance of contaminants exceeding reference
ground-water concentrations. Contaminants which can be objec-
tively ranked in this manner are presented in Table C3.
d. Proportion of sediment sampling sites in the area being eval-
uated that have test leachates exceeding reference ground-
water concentrations. (If a single composite sample from
the dredging area is analyzed, this factor drops from
consideration.)
The local authority might choose to reach a DECISION OF NO RESTRICTIONS re-
quired to protect against contaminant impacts on the ground water. This may
be appropriate if samples from only a few sites have only a small number of
contaminants of relatively low toxicological concern exceeding the reference
by a small amount. In contrast, the local authority might choose to reach a
DECISION FOR RESTRICTION required to protect against contaminant impacts on
the ground water. This may be appropriate if samples from a number of sites
have several contaminants of relatively high toxicological concern exceeding
the reference ground water. Some potentially appropriate restrictions are
described in paragraphs 81-92 and 95. If the local authority desires to fully
evaluate the potential for ground-water impacts to occur, it will reach a
DECISION FOR FURTHER EVALUATION by considering bioassays as discussed in
paragraph B57-
B45
-------
B56. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph B5S using the following quantitative approach.
This quantitation was selected for use when Commencement Bay area goals (para-
graph 70) require the use of a relatively pristine reference 3 as is the case
in the example in Part III and Tables 3-21. Other values may be necessary to
achieve local goals that utilize a less pristine reference. Although con-
ceptually similar approaches could be taken elsewhere, the approach and its
quantitation would have to be tailored specifically to local goals. The au-
thors do not necessarily advocate either quantitation of the guidance of para-
graph B55 or its quantitation in the following manner since the guidance con-
siderations may be complexly interactive. The approach described below is the
initial approach tentatively selected by Commencement Bay area authorities and
should not be construed as final Commencement Bay area guidance nor as implied
guidance or a precedent for actual LADs elsewhere.
a. Number of contaminants. If 25 percent or less of the contami-
nants of concern exceed reference, there is cause for low
cern. If 25 percent-90 percent of the contaminants of concern
exceed reference, there is cause for moderate concern. If
90 percent or more of the contaminants of concern exceed ref-
erence, there is cause for high concern.
Magnitude above reference. If test concentration is less than
or equal to 25 times reference concentration, there is cause
for low concern. ff any contaminant of concern is greater
than 25 and up to 100 times reference concentration, there is
cause for moderate concern. If any contaminant of concern is
100 or more times reference concentration, there is cause for
high concern.
lexicological importance. If the contaminants of concern are
rank 1 or 2 in Table C3, there is cause for low concern. If
any contaminant of concern is rank 3 or 4 in Table C3, there
is cause for moderate concern. If any contaminant of concern
is rank 5 or 6 in Table C3, there is cause for high concern.
(Unranked contaminants of concern are cause for moderate con-
cern unless there is additional evidence to reasonably warrant
a different level of concern.)
Number of sampling sites. If 50 percent or less of the sedi-
ment sampling sites in the dredging area being evaluated have
any contaminant of concern exceeding the reference, there is
cause for low concern. If more than 50 percent of the sediment
sampling sites in the area being evaluated have any contaminant
of concern exceeding the reference, there is cause for high
concern . (If a single composite sample from the dredging area
is analyzed, this factor drops from consideration.)
B46
-------
Findings of low concern in all factors, a through d, lead to a DECISION OF NO
RESTRICTIONS required to protect against contaminant impacts in the ground
water. A finding of moderate or high concern in two or more factors leads to
a DECISION OF RESTRICTIONS required to protect against contaminant impacts in
the ground water. Some potentially appropriate restrictions are described
in paragraphs 81-92 and 95. All other combinations of findings lead to a
DECISION FOR FURTHER EVALUATION by considering a water column bioassay as
discussed in paragraph B57.
DECISION FOR FURTHER EVALUATION: BIOASSAYS
B57. Water column bioassays of the test leachate can give two possible
results:
a. Toxiclty of the test leachate to all species is less than
50 percent of the reference ground water. This leads to a
DECISION OF NO RESTRICTIONS required to protect against con-
taminant Impacts on the ground water.
b. Toxicity of the test leachate to any species is equal to or
greater than 50 percent of the reference ground water. This
leads to a LOCAL AUTHORITY DECISION.
LOCAL AUTHORITY DECISION; RESTRICTIONS/CONSIDER MIXING
B58. In the case of subparagraph B57b, the local authority might choose,
without considering mixing, to reach a DECISION FOR RESTRICTIONS required to
protect against contaminant impacts on nonpotable ground water. Some poten-
tially appropriate restrictions are described in paragraphs 81-92 and 95. If
the local authority desires to. fully evaluate the potential for nonpotable
ground-water impacts to occur, it will reach a DECISION FOR FURTHER EVALUATION
by considering mixing as discussed in paragraph B60.
B59. Commencement Bay area authorities have tentatively decided not to
consider mixing when a nonpotable ground water resurfaces into a water body.
Consequently, a DECISION FOR RESTRICTIONS will be reached for water column
bioassay results described in paragraph B57b. Commencement Bay area authori-
ties have tentatively decided to consider the benthic impacts of a nonpotable
ground water resurfacing through sediments of the receiving water body. As
ground water passes through the sediments, contaminants may be adsorbed to the
sediments, resulting in accumulation of ground-water contaminants. The impact
of these contaminants on benthic organisms could be evaluated from the results
of a benthic bioassay on the originally dredged sediment assuming a worst case
of all the contaminants leaching into the ground water and then being accumu-
lated in the sediments of the receiving water body. Decisions for this
B47
-------
scenario are similar to the benthic impacts of aquatic disposal that were
discussed in Appendix A (Figure A2 and paragraphs A19-A2S).
DECISION FOR FURTHER EVALUATION: CONSIDER MIXING
B60. Consideration of a mixing zone when nonpotable ground water emerges
into a water body such as a river or bay can give two possible results:
a. A mixing zone of acceptable size and/or configuration (para-
graph 34) within which the nonpotable ground-water discharge
will be diluted to less than an LC50. This leads to a DECI-
SION FOR NO RESTRICTIONS required to protect against possible
contaminant impacts on the receiving water body.
b. A mixing zone of unacceptable size and/or configuration (para-
graph 34) within which the nonpotable ground-water discharge
will not be diluted and will still be equal to or greater than
the LC50. This leads to a DECISION FOR RESTRICTIONS required
to protect against degradation of the receiving water body.
Some potentially appropriate restrictions are described in
paragraphs 81-92 and 95.
Plant Uptake Tests
DECISIONS FROM PLANT UPTAKE/BIOASSAY TESTS
B61. Plant uptake/bioassay tests will indicate the potential for con-
taminants to impact plants colonizing the sediment to be dredged. Plant
response is observed when index plants are grown in the sediment under both a
flooded wetland condition and a dried upland condition as described in para-
graph 61. Plant response is also observed in a reference sediment or soil
selected according to paragraph 70. Both plant growth and bioaccumulation of
contaminants are evaluated (Figure B6). Plant response to the contaminanted
sediment should always be compared to the plant response to the reference
sediment or soil. Data from existing literature on demonstrated effects of
contaminants on plants (Tables C5 and C6) can be used to indicate potential
effects of contaminant concentrations in test plants in relation to other
plants and can give some perspective to the magnitude of the impact. Avail-
able FDA action levels for contaminants in plants and foodstuffs (Table C7)
and existing standards for contaminant levels in food plants for protection of
human health (Table C8) can be used to get additional perspective on contami-
nant concentrations in plant tissues that have potential health effects. Total
plant uptake of contaminants should also be evaluated. Total uptake is cal-
culated by multiplying the plant tissue concentration of contaminant by the
total dry weight of plant leaves produced. Total uptake indicates the total
B48
-------
PLANT
UPTAKE'
OTPA
-EXTRACT-
- REFERENCE >TEST^SATURATEO—*—I
- REFERENCE > TEST > SATURATE
-REFERENCE< TEST^SATURATI
- REFERENCE < TEST > SATURATED » PLANT
NO RESTRICTIONS!
QROWTH-^—
-TEST >REFERENCE—»»
-•>— BIOACCUMULATION-
B67
- TEST < REFERENCE
RESTRICTIONS
W
4S
vO
-TEST REFERENCE. < EFFECTS. < FDA
TEST >HEFERENCE.<_EFFECTS. NO FDA
TEST > REFERENCE. NO EFFECTS, <^FDA
TEST < REFERENCE. > EFFECTS. < FDA
TEST^REFERENCE. > EFFECTS. NO FDA
-TEST >REFERENCE. >EFFECTS. < FOA.^—
B69
B71
-TEST >REFERENCE. >EFFECTS. >FDA
TEST >REFERENCE. >EFFECTS. NO FDA
TEST > REFERENCE. < EFFECTS, >FDA
TEST^REFERENCE. > EFFECTS. >FDA
TEST^REFERENCE,^EFFECTS. >FDA
TEST > REFERENCE. NO EFFECTS. > FDA
-TEST< REFERENCE. NO EFFECTS. >FDA-
RESTRICTIONS
Figure B6. Flowchart for decisionmaking for potential plant uptake
(number near LAD is paragraph discussing LAD)
-------
mobility of contaminants from the sediment into aboveground portions of the
plant. A complete picture of the plant uptake of contaminants from sediments
can only be obtained after consideration of both plant tissue content and total
uptake values.
DECISIONS FROM DTPA-SEDIMENT EXTRACTION TESTS
B62. DTPA-extractable metals from air-dried contaminated sediment should
always be compared to DTPA-extractable metals from the original wet contamin-
ated sediment and from a reference sediment. The reference sediment or soil
is selected according to paragraph 70. DTPA extraction is effective for
metals, but cannot predict potential organic contaminant mobility. There is
no simplified laboratory extraction that predicts potential organic contaminant
mobility into plants. Research data to date have not indicated bioaccumulation
of organic comtaminants in test plants to any greater extent over reference
plants.
B63. DTPA sediment extraction tests are described in paragraph 62 and
can result in four possible conditions:
a. DTPA-extractable concentrations of all metals from the air-
: dried sediment are less than or equal to the reference and
less than or equal to the saturated sediment. This leads to
a DECISION OF NO RESTRICTIONS to protect against contaminant
impacts on plants colonizing the dredged material.
b. DTPA-extractable concentrations of any metal from the air-
dried sediment is less than or equal to the reference and
greater than the saturated sediment or
£. DTPA-extractable concentrations of any metal from the air-
dried sediment is greater than the reference and lees than
or equal to the saturated sediment.
Condition b and c lead to a LOCAL AUTHORITY DECISION as
discussed in paragraph B64.
ci. DTPA-extractable concentrations of any metal from the air-
dried sediment is greater than the reference and greater than
the saturated sediment. This leads to a DECISION FOR FURTHER
EVALUATION by conducting a plant bioassay as discussed in
paragraph B66.
LOCAL AUTHORITY DECISION; RESTRICTIONS/NO RESTRICTIONS/CONSIDER BIOASSAYS
B64. Under the condition of subparagraph B63b, the local authority
might choose to reach a DECISION OF NO RESTRICTION required to protect against
contaminant impacts on plants colonizing the contaminated dredged material.
This may be appropriate since plants will not be any more contaminated than
B50
-------
those grown on the reference sediment even though contaminant mobility appears
to have increased in the air-dried sediment compared to the saturated sedi-
ment. This may also be appropriate if samples from only a few sites have only
a small number of contaminants of relatively low toxicological concern exceed-
ing the saturated sediment values by a small amount. In the case of subpara-
graph B63c, the local authority might choose to reach a DECISION OF NO RESTRIC-
TIONS required to protect against contaminant impacts on plants colonizing the
contaminated dredged material. This may be appropriate if samples from only a
few sites have only a small number of contaminants of relatively low toxi-
cological concern exceeding the reference sediment values by a small amount.
If the local authority desires to fully evaluate the potential for contaminant
impacts on plants colonizing the contaminated dredged material to occur in
light of the test results obtained in subparagraphs B63b and c, it will reach
a DECISION FOR FURTHER EVALUATION by conducting a plant bioassay as discussed
in paragraph B66.
B65. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph B64 using the following quantitative approach.
This quantitation was selected for use when Commencement Bay area goals
(paragraph 70) require the use of a relatively pristine referencet as is the
case in the example in Part III and Tables 3-21. Other values may be neces-
sary to achieve local goals that utilize a less pristine reference. Although
conceptually similar approaches could be taken elsewhere, the approach and its
quantitation would have to be tailored specifically to local goals. The
authors do not necessarily advocate either quantitation of the guidance of
paragraph B64 or its quantitation in the following manner since the guidance
considerations may be complexly interactive. The approach described below is
the initial approach tentatively selected by Commencement Bay area authorities
and should not be construed as final Commencement Bay area guidance nor as
implied guidance or a precedent for actual LADs elsewhere.
a. Number of contaminants. If 25 percent or less of the contam-
inants of concern are extracted from the air-dried dredged
material in concentrations exceeding those from the air-dried
reference sediment or the saturated dredged material, there is
cause for low concern. If more than 25 percent of the contam-
inants of concern are extracted from the air-dried dredged
material in concentrations exceeding those from the air-dried
reference sediment or the saturated dredged material, there
is cause for high concern.
B51
-------
b. Magnitude above reference. If air-dried dredged material pro-
duces DTPA-extracted metal concentrations of 10 Of less times
higher than those from the air-dried reference sediment or the
saturated dredged material, there is cause for low concern.
If air-dried dredged material produces extract concentrations
of more than 10 times the extract concentration from the air-
dried reference sediment or the saturated dredged material,
there is cause for high concern.
£. Toxicological importance. If the contaminants of concern
extracted from air-dried dredged material in concentrations
exceeding air-dried reference sediment concentrations or
saturated dredged material concentrations are rank 1-5 in
Table C3, there is cause for low concern. If contaminants
of concern extracted from air-dried dredged material are
unranked or ranked 4-6 in Table C3, there is cause for high
concern.
d. Number of sampling sites. If 50 percent or less of the sedi-
ment sampling sites in the dredging area being evaluated
produce DTPA-extracted metal concentrations from air-dried
dredged material exceeding the air-dried reference sediment
or the saturated dredged material, there is cause for low
concern. If more than 50 percent of the sediment sampling
sites produce DTPA-extracted metal concentrations from air-
dried dredged material exceeding the air-dried reference
sediment or the saturated dredged material, there is cause
for high concern.
Findings of low concern in all factors lead to a DECISION OF NO RESTRICTIONS
required to protect from possible adverse impacts of dredged material disposed
in the upland environment. A finding of high concern in more than one of the
factors.leads to a DECISION FOR FURTHER EVALUATION by conducting a plant bio-
assay as discussed in paragraph B66.
DECISIONS FROM PLANT BIOASSAY EVALUATIONS
B66. Plant bioassays as discussed in paragraphs 60 and 61 are evaluated
in two phases, a growth phase evaluation and then a bioaccumulation phase
(Figure B6). Plant growth can result in:
a. Air-dried sediment produces plant yield equal to or greater
than that on the reference sediment. Up to 25 percent reduc-
tion in plant yield would be acceptable if the test sediment
has poor fertility. This leads to a DECISION FOR FURTHER
EVALUATION to assess potential bioaccumulation by conducting
the bioaccumulation phase of the bioassay as discussed in
paragraph B68.
b_. Air-dried sediment produces a reduction in plant yield of
25 percent or greater of that on the reference sediment.
This leads to a LOCAL AUTHORITY DECISION.
B52
-------
LOCAL AUTHORITY DECISION: RESTRICTIONS/CONSIDER BIOACCUMULATION
B67. Under the conditions of subparagraph B66b, the local authority
might choose to reach a DECISION FOR FURTHER EVALUATION by conducting the bio-
accumulation phase of the plant bioassay. This is appropriate if there is
reason to believe the reduction in growth might be a result of low fertility
in the sediment or a result of excess salt in the case of estuarine sediments.
On the other hand, the local authority might choose to reach a DECISION FOR
RESTRICTIONS required to protect against contaminant impacts on plants coloniz-
ing the dredged material. This is appropriate if there is reason to believe
that the reduction in growth was due to toxic metals or phytotoxic organic
contaminants and not a result of infertility or salinity. Some potentially
appropriate restrictions are described in paragraphs 81-92 and 96.
DECISIONS FROM PLANT BIOACCUMULATION EVALUATIONS
B68. Plant bioaccumulation tests are described in paragraphs 60 and 61
and can give 17 possible sets of results grouped according to the appropriate
decision to be made.
a. Exposed plant tissue concentrations are less than or equal to
reference plant tissues and less than or equal to demonstrated
effects (Tables C5 and C6) and less than or equal to FDA ac-
tion levels (Table C7) or other human health effects levels
(Table C8).
b. Exposed plant tissue concentrations are less than or equal to
~ reference plant tissues (but no demonstrated effects data
exist) and are less than or equal to FDA action levels
(Table C7) or other human health effects levels (Table A8).
£. Exposed plant tissue concentrations are less than or equal
~ to_ reference plant tissues and less than or equal to
demonstrated effects (Tables C5 and C6) but no FDA action
levels or other human health effects levels exist.
Conditions a, b, and c lead to a DECISION OF NO RESTRICTIONS
required to protect against contaminant impact on plants colo-
nizing the dredged material.
d. Exposed plant tissue concentrations are greater than reference
~ plant tissue and greater than demonstrated effects (Tables C5
and C6) and greater than FDA~"levels (Table C7) or other human
health levels (Table C8).
e. Exposed plant tissue concentrations are greater than reference
~~ platit tissues and greater than demonstrated effects (Tables C5
and C6) and there are no FDA or other human health levels.
B53
-------
f_. Exposed plant tissue concentrations are greater than reference
plant tissues and less than or equal to demonstrated effects
(Tables C5 and C6) and greater than FDA levels (Table C7) or
other human health levels (Table C8).
£. Exposed plant tissue concentrations are less than or equal to
reference plant tissues and greater than demonstrated effects
(Tables C5 and C6) and greater than FDA 'levels (Table C7) or
other human health levels (Table C8).
h. Exposed plant tissue concentrations are less than or equal to
reference plant tissues and less than OT~equal to demonstrated
effects (Tables C5 and C6) and greater than FDA levels
(Table C7) or other human health levels (Table C8).
_i. Exposed plant tissue concentrations are greater than reference
plant tissues (but no demonstrated effects data exist) and
are greater than FDA levels (Table C7) or other human health
levels (Table C8).
j_. Exposed plant tissue concentrations are less than or equal
to_ reference plant tissues (but no demonstrated effects ~aata
exist) and are greater than FDA levels (Table C7) or other
human health levels (Table C8).
Conditions d-^ lead to a DECISION FOR RESTRICTIONS' required to
protect against contaminant impact on plants colonizing the
dredged material. Some potentially appropriate restrictions
are described in paragraphs 81-92 and 96.
k. Exposed plant tissue concentrations are less than or equal to
reference plant tissues and there are no effects data or no
FDA levels.
^. Exposed plant tissue concentrations are greater than reference
plant tissues and less than or equal to demonstrated effects
(Tables C5 and C6) and less than or equal to FDA action levels
(Table C7) or other human health effects levels (Table C8).
m. Exposed plant tissue concentrations are greater than reference
plant tissues and less than OP equal to demonstrated effects
(Tables C5 and C6) and there are no FDA or other human health
levels.
n. Exposed plant tissue concentrations are greater than reference
plant tissues (but no demonstrated effects data exist), and
are less than or equal to FDA levels (Table C7) or other human
health levels (Table C8).
£. Exposed plant tissue concentrations are less than or equal to
reference plant tissues and greater than demonstrated effects
(Tables C5 and C6) and less than or equal to FDA levels
(Table C7) or other human health levels (Table C8).
£. Exposed plant tissue concentrations are less than or equal to
reference plant tissues, and greater than demonstrated effects
(Tables C5 and C6) but there are no FDA or other human health
levels.
B54
-------
£. Exposed plant tissue concentrations are greater* than reference
plant tissues and greater than demonstrated effects (Tables C5
and C6) and less than or equal to FDA levels (Table C7) or
other human health levels (Table C8).
Conditions k-£ lead to a LOCAL AUTHORITY DECISION as discussed
in paragraph B69.
LOCAL AUTHORITY DECISION; RESTRICTIONS/NO RESTRICTIONS/CONSIDER TOTAL PLANT
UPTAKE
B69. At present it is not possible to provide sufficient scientific
basis for deciding on the need for restrictions on the cases of subpara-
graphs B68k, 1., m, n, £, p_, and £. Therefore, the local authority must make
an administrative decision using the available scientific information and
locally important concerns. In interpreting plant bioaccumulation data,
scientific concern over potential adverse impacts associated with bioaccumu-
lation increases in direct relation to:
si. Number of contaminants bioaccumulated to concentrations ex-
ceeding reference and/or demonstrated effects levels.
b. Magnitude of bioaccumulation above reference and/or demon-
strated effects levels.
£. Toxicological importance of contaminants bioaccumulated to
concentrations exceeding reference and/or demonstrated effects
levels. Contaminants that can be objectively ranked in this
manner are presented in Table C3.
d_. Proportion of sediment sampling sites in the area being eval-
uated that show bioaccumulation to concentrations exceeding
reference and/or demonstrated effects levels.
In the cases of subparagraphs B68k, _!, m, n, o_, p_, and £, the local authority
may choose, without considering total plant uptake, to reach a DECISION OF
NO RESTRICTIONS required to protect against contaminant impacts on plants
colonizing the dredged material. This may be appropriate if samples from only
a few sites have only a small number of 'contaminants of relatively low
toxicological concern exceeding the reference by a small amount. On the other
hand, the local authority may choose, without considering total plant uptake,
to reach a DECISION FOR RESTRICTIONS required to protect against contaminant
impacts on plants colonizing the dredged material. This may be appropriate
if samples from a number of sites have several contaminants of relatively
high toxicological concern exceeding the reference by a substantial margin.
Some potentially appropriate restrictions are described in paragraphs 81-92
and 95. In addition, if the local authority desires to fully evaluate the
B55
-------
potential for mass movement of contaminants into plants, it will reach a
DECISION FOR FURTHER EVALUATION by considering total plant uptake as discussed
in paragraph B71.
B70. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph B69 using the following quantitative approach.
This quantitation was selected for use when Commencement Bay area goals (para-
graph 70) require the use of a relatively pristine reference, as is the case
in the example in Part III and Tables 3-21. Other values may be necessary to
achieve local goals that utilize a less pristine reference. Although con-
ceptually similar approaches could be taken elsewhere, the approach and its
quantitation would have to be tailored specifically to, local goals. The au-
thors do not necessarily advocate either quantitation of the guidance of para-
graph B69 or its quantitation in the following manner since the guidance con-
siderations may be complexly interactive. The approach described below is the
initial approach tentatively selected by Commencement Bay area authorities and
should not be construed as final Commencement Bay area guidance nor as implied
guidance or a precedent for actual LADs- elsewhere.
a. Number of contaminants. If 25 percent or less of the contami-
nants of concern (either metals or organics) are bioaccumu-
lated to concentrations exceeding those in reference plants,
there is cause for low concern. If more than 25 percent of
the contaminants of concern (either metals or organics) ex-
ceed reference plants, there is cause for high concern.
b. Magnitude of tissue concentration. If dredged material
produces tissue contaminant concentrations within the normal
range and below the critical content shown in Table C5, there
is cause for low concern.If dredged material produces tissue
contaminant concentrations greater than the normal range and
equal to or greater than the critical content shown in
Table C5, there is cause for high concern.
£. Magnitude above reference. If dredged material produces
tissue contaminant concentrations 10 or less times higher
than reference tissue concentrations, there is cause for low
concern. If dredged material produces tissue concentrations
more than 10 times the reference tissue concentration, there
is cause for high concern.
d. Toxicological importance. If the contaminants of concern bio-
accumulated to concentrations exceeding reference levels are
rank 1-3 in Table C3, there is cause for low concern. If the
bioaccumulated contaminants are ranked 4-6 in Table C3, there
is cause for high concern. (Unranked contaminants of concern
are cause for moderate concern unless there is additional evi-
dence to reasonably warrant a different level of concern.)
B56
-------
£. Number of sampling sites. If 50 percent or less of the sedi-
ment sampling sites in the dredging area being evaluated pro-
duce bioaccumulation exceeding the reference sediment, there
is cause for low concern. If move than 50 percent of the
sediment sampling sites produce bioaccumulation exceeding
the reference sediment, there is cause for high concern.
(If a single composite sample from the dredging area is
tested, this factor drops from consideration.)
Findings of lew concern in all factore lead to a DECISION OF NO RESTRICTIONS
required to protect from possible adverse impacts of dredged material disposal
in the upland environment. A finding of moderate or high concern in one or
more factors leads to a DECISION OF RESTRICTIONS required to protect from pos-
sible adverse contaminant impacts of dredged material disposal in the upland
environment. Some potentially appropriate restrictions of such cases are dis-
cussed in paragraphs 81-92 and 96.
DECISIONS FROM TOTAL PLANT UPTAKE EVALUATIONS
B71. Total plant uptake of contaminants can indicate potential mass
movement of contaminants from the dredged material into plants. This is done
by comparing the total uptake of contaminants (plant tissue concentration
multiplied by total plant yield) from the contaminated sediment to that from
the reference sediment:
a. If total uptake is greater on the contaminated sediment than
that from the reference sediment, then the local authority
may choose to reach a DECISION FOR RESTRICTIONS. This may
be appropriate in relation to the factors discussed in para-
graph B70 if samples from a number of sites have several con-
taminants of relatively high toxicological concern exceeding
the reference by a substantial margin. On the other hand,
the local authority might choose to reach a DECISION OF NO
RESTRICTIONS required to protect against contaminant impacts
on plants colonizing the dredged material. This may be ap-
propriate if samples from only a few sites have only a small
number of contaminants of relatively low toxicological con-
cern exceeding the reference by a small amount.
b. If total uptake is less than or equal to that from the refer-
~~ ence sediment, then the local authority might reach a DECISION
OF NO RESTRICTIONS required to protect against contaminant im-
pacts on plants colonizing the dredged material. This may be
appropriate since contaminant mobility from the contaminated
sediment into plants will not be any greater than existing
contaminant mobility from the reference sediment into plants
colonizing it.
B72. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph B71 using the following quantitative approach.
B57
-------
This quantitation was selected for use when Commencement Bay area goals (para-
graph 70) require the use of a relatively pristine reference3 as is the case
in the example in Part III and Tables 3-21. Other values may be necessary to
achieve local goals that utilize a less pristine reference. Although con-
ceptually similar approaches could be taken elsewhere, the approach and its
quantitation would have to be tailored specifically to local goals. The au-
thors do not necessarily advocate either quantitation of the guidance of para-
graph B71 or its. quantitation in the following manner since the guidance con-
siderations may be complexly interactive. The approach described below is the
initial approach tentatively selected by Commencement Bay area authorities and
should not be construed as final Commencement Bay area guidance nor as implied
guidance or a precedent for actual LADs elsewhere.
£. Number of contaminants. If 25 percent or less of the contami-
nants of concern show total uptake from the dredged material
exceeding that from the reference sediment, there is cause for
low concern. If more than 25 percent of the contaminants of
concern show total uptake from the dredged material exceed-
ing that from reference sediment, there is cause for high
concern.
b. Magnitude above reference. If dredged material produces total
uptake of contaminants of concern 10 or less times higher than
that from the reference sediment, there is cause for low con-
cern. If dredged material produces total uptake of contami-
nants of concern more than 10 times that from the reference
sediment, there is cause for high concern.
c. Toxicological importance. If the contaminants of concern
showing total uptake from the dredged material exceeding ref-
erence levels are rank 1-2 in Table C3, there is cause for
low concern. If the contaminants of concern showing total up-
take from the dredged material exceeding reference levels are
ranked 4-6 in Table C3, there is cause for high concern. (Un-
ranked contaminants of concern are cause for moderate concern
unless there is additional evidence to reasonably warrant a
different level of concern.)
cl. Number of sampling sites. If 50 percent or less of the sed-
iment sampling sites in the dredging area being evaluated
produce total uptake values exceeding those of the refer-
ence sediment, there is cause for low concern. If more than
50 percent of the sediment sampling sites produce total up-
take values exceeding the reference sediment, there is cause
for high concern. (If a single composite sample from the
dredging area is tested, this factor drops from
consideration.)
Findings of low concern in all factors lead to a DECISION OF NO RESTRICTIONS
required to protect from adverse impacts of dredged material disposal in the
B58
-------
upland environment. A finding of moderate or high concern in one or more foo-
ters leads to a DECISION OF RESTRICTIONS required to protect from possible ad-
verse contaminant impacts of dredged material disposal in the upland environ-
ment. Some potentially appropriate restrictions of such cases are discussed
in paragraphs 81-92 and 96.
Animal Uptake Tests
DECISIONS FROM ANIMAL UPTAKE/BIOASSAY TESTS
B73. Test animal response is observed after exposure to a contaminated
sediment as described in paragraphs 63-65. Test animal response is also
observed after exposure to a reference sediment or soil selected in accordance
with paragraph 70. Both animal toxicity and bioaccumulation of contaminants
are evaluated. Test animal response to contaminated sediment should always be
compared to the response observed to the reference sediment or soil. Available
FDA action levels for poisonous substances in human food (Table Cl) can be
used to get additional perspective on contaminant concentrations in organisms
that have potential health effects. A direct correlation between earthworm
content of contaminants and human health effects cannot be made. The earthworm
bioassay only indicates the potential for contaminants to move from sediments
into animals that come in contact with the sediment. Total animal uptake of
contaminants should also be evaluated. Total uptake is calculated by multiply-
ing the animal tissue concentration by the total dry weight of animal tissue
produced. Total uptake indicates the total mobility of contaminants from the
sediment into the test animal. A complete picture of the animal uptake of
contaminants from sediments can only be obtained after consideration of both
animal tissue content and total uptake values.
DECISIONS FROM ANIMAL TOXICITY EVALUATIONS
B74. Animal toxicity tests are described in paragraphs 63-65 and can
result in four conditions (Figure B7):
a. Exposed toxicity is greater than the reference sediment and
~ equal to or greater than 50 percentage points above the con-
trol. This leads to a DECISION FOR RESTRICTIONS required to
protect against contaminant impacts on sediment-dwelling ani-
mals beyond existing reference site conditions.
B59
-------
ANIMAL
UPTAKE"
EARTHWORM^
"BIOASSAY
-TOXICITY-
-REFERENCE > TEST < 50%-
1EFERENCE > TEST > 50%-».
-REFERENCE < TEST < 50%-
-»• BIOACCUMULATION-
-REFERENCE < TEST > 50%-
RESTRICTIONS
W
ON
O
-REFERENCE >TEST < FDA
-REFERENCE< TEST < FDA
-REFERENCE < TEST NO FDA
-REFERENCE >TEST NO FDA-J
-REFERENCE < TEST >FDA
-REFERENCE >TEST>FDA
Figure B7. Flowchart for decisioranaking for potential animal uptake
(number near LAD is paragraph discussing LAD)
-------
b. Exposed toxlcity is lees than or equal to the reference sedi-
ment and less than 50 percentage points above the control.*
c. Exposed toxicity is less than ov equal to the reference sedi-
ment and equal to or greater than 50 percentage points above
the control, or
d. Exposed toxicity is greater than the reference sediment and
less than 50 percentage points above the control.
Conditions under subparagraph B74b, c_, and d lead to a DECISION FOR FURTHER
EVALUATION by assessing the potential for bioaccumulation of contaminants of
concern from the test sediment as discussed in paragraph B75.
DECISIONS FROM ANIMAL BIOACCUMULATION EVALUATIONS
B75. The local authority must evaluate the potential for bioaccumulation
of contaminants from sediment/dredged material. Bioaccumulation tests can
result in six conditions:
a. Concentrations of all contaminants of concern in the tissues
of animals exposed to the test sediment are less than or equal
to_ concentrations in animals exposed to the reference sedi-
ment and leas than FDA type limits (Table Cl). This leads
to a DECISION OF NO RESTRICTIONS required to protect against
contaminant impacts on soil-dwelling animals that colonize
the dredged material.
b_. Concentration of any contaminant of concern in the tissue of
animals exposed to the test sediment are greater than refer-
ence animals and equal to or greater than FDA type limits
(Table Cl), or
£. Concentrations of any contaminant of concern in the tissues of
exposed animals are less than or equal to reference animals
and equal to or greater than FDA-type limits (Table Cl).
Conditions under subparagraphs B75b and £ lead to a DECISION
FOR RESTRICTIONS required to protect against possible contam-
inant impacts on soil dwelling animals that colonize the dis-
posal site. Some potentially appropriate restrictions are
described in paragraphs 81-92 and 96.
d. Concentrations of any contaminant of concern in the tissues
of animals exposed to the test sediment are greater than
reference animals and lees than FDA-type limits (Table Cl),
or
* For example, if 9 of 100 control animals showed mortality, then at least
59 of 100 test animals (59 percent) would have to show mortality in order
for toxicity of the test sediment to be 50 percentage points above the
control.
B61
-------
e.. Concentrations of any contaminant of concern in the tissues
of animals exposed to the test sediment are greater them ref-
erence animals and no FDA-type limits have been established
(Table Cl), or
f_. Concentrations of any contaminant of concern in the tissues of
animals exposed to the test sediment are less than or equal to
reference animals and no FDA-type limits have been established
(Table Cl).
Conditions under subparagraphs B75d, e_, and f_ lead to a LOCAL
AUTHORITY DECISION.
LOCAL AUTHORITY DECISION; RESTRICTIONS/NO RESTRICTIONS/CONSIDER TOTAL ANIMAL
UPTAKE
B76. At present it is not possible to provide sufficient scientific
basis for deciding on the need for restrictions on the cases of subpara-
graphs B75d_, e_, and f_. Therefore, the local authority must make an administra-
tive decision using the available scientific information and locally important
concerns. In interpreting animal bioaccumulation data, scientific concern
over potential adverse impacts associated with bioaccumulation increases in
direct relation to:
a. Number of contaminants bioaccumulated to concentrations
exceeding reference and/or demonstrated effects levels.
b. Magnitude of bioaccumulation above reference and/or demon-
strated effects levels.
£. Toxicological importance of contaminants bioaccumulated to
concentrations exceeding reference and/or demonstrated effects
levels. Contaminants that can be objectively ranked in this
manner are presented in Table C3.
cl. Proportion of sediment sampling sites in the area being eval-
uated that show bioaccumulation to concentrations exceeding
reference and/or demonstrated effects levels.
In the cases of subparagraphs B75d, e_, and f_, the local authority may choose,
without considering total animal uptake, to reach a DECISION OF NO RESTRIC-
TIONS required to protect against contaminant impacts on soil-dwelling animals
colonizing the dredged material. This may be appropriate if samples from only
a few sites have only a small number of contaminants of relatively low toxico-
logical concern exceeding the reference by a small amount. On the other hand,
the local authority may choose, without considering total animal uptake, to
reach a DECISION FOR RESTRICTIONS required to protect against contaminant
B62
-------
Impacts on soil-dwelling animals colonizing the dredged material. This may be
appropriate if samples from a number of sites have several contaminants of
relatively high toxicological concern exceeding the reference by a substan-
tial margin. Some potentially appropriate restrictions are described in para-
graphs 81-92 and and 96. In addition, if the local authority desires to fully
evaluate the potential mass movement of contaminants into soil-dwelling ani-
mals, it will reach a DECISION FOR FURTHER EVALUATION by considering total
animal uptake as discussed in paragraph B78.
B77. Commencement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph B76 using the following quantitative approach.
This quantitation was selected for use when Commencement Bay area goals (para-
graph 70) require the use of a relatively pristine referencet as is the case
in the example in Part III and Tables 3-21. Other values may be necessary to
achieve local goals that utilize a less pristine reference. Although con-
ceptually similar approaches could be taken elsewhere, the approach and its
quantitation would have to be tailored specifically to local goals'. The au-
thors do not necessarily advocate either quantitation of the guidance of para-
graph B?6 or its quantitation in the following manner since the guidance con-
siderations may be complexly interactive. The approach described below is the
initial approach tentatively selected by Commencement Bay area authorities and
should not be construed as final Commencement Bay area guidance nor as implied
guidance or a precedent for actual LADs elsewhere.
a. Number of contaminants. If 25 percent or less of the contami-
nants of concern are bioaccumulated to concentrations exceed-
ing those in reference animals, there is cause for low concern.
If more than 25 percent of the contaminants of concern exceed
reference animals, there is cause for high concern.
b_. Magnitude above reference. If dredged material produces tis-
sue contaminant concentrations 10 or less times higher than
reference tissue concentrations, there is cause for low con-
cern. If dredged material produces tissue concentrations
more than 10 times the reference tissue concentration, there
is cause for high concern.
c_. Toxicological importance. If the contaminants of concern bio-
accumulated to concentrations exceeding reference levels are
rank 1-3 in Table C3, there is cause for low concern. If the
bioaccumulated contaminants are ranked 4-6 in Table C3, there
is cause for high concern. (Unranked contaminants of concern
are cause for moderate concern unless there is additional evi-
dence to reasonably warrant a different level of concern.)
B63
-------
d. Number of sampling sites. If 50 percent or less of the sedi-
ment sampling sites in the dredging area being evaluated pro-
duce bioaccumulation exceeding the reference sediment, there
is cause for low concern. If more than 50 percent of the sed-
iment sampling sites produce bioaccumulation exceeding the
reference sediment, there is cause for high concern. (If
a single composite sample from the dredging area is tested,
this factor drops from consideration.)
Findings of low concern in all factors lead to a DECISION OF NO RESTRICTIONS
required to protect from possible adverse impacts of dredged material disposal
in the upland environment. A finding of moderate or high concern in one or
more factors leads to a DECISION OF RESTRICTIONS required to protect from pos-
sible adverse contaminant impacts of dredged material disposal in the upland
environment. Some potentially appropriate restrictions of such cases are dis-
cussed in paragraphs 81-92 and 96.
DECISIONS FROM TOTAL ANIMAL UPTAKE EVALUATIONS
B78. Total animal uptake of contaminants can indicate potential mass
movement of contaminants from the dredged material into soil-dwelling animals.
This is done by comparing the total uptake of contaminants (animal tissue con-
centration multiplied by total animal weight) from the contaminated sediment
to that from the reference sediment:
a. If total uptake is greater on the contaminated sediment than
that from the reference sediment, then the local authority
may choose to reach a DECISION FOR RESTRICTIONS. This may
be appropriate in relation to the factors discussed in para-
graph B76 if samples from a number of sites have several con-
taminants of relatively high toxicological concern exceeding
the reference by a substantial margin. On the other hand,.
the local authority might choose to reach a DECISION OF NO
RESTRICTIONS required to protect against contaminant impacts
on animals colonizing the dredged material. This may be ap-
propriate if samples from only a few sites have only a small
number of contaminants of relatively low toxicological con-
cern exceeding the reference by a small amount.
b. If total uptake is less than or equal to that from the refer-
ence sediment, than the local authority might reach a DECISION
OF NO RESTRICTIONS required to protect against contaminant im-
pacts on animals colonizing the dredged material. This may be
appropriate since contaminant mobility from the contaminated
sediment into soil-dwelling animals will not be any greater
than existing contaminant mobility from the reference sediment
into animals colonizing it.
B64
-------
B79, Commenoement Bay area authorities have tentatively decided to make
the LAD discussed in paragraph B78 using the following quantitative approach.
This quantitation was selected for use when Commencement Bay area goals
(paragraph 70) require the use of a relatively pristine reference, as is the
case in the example in Part III and Tables 3-21. Other values may be neces-
sary to achieve local goals that utilise a less pristine reference. Although
conceptually similar approaches could be taken elsewhere, the approach and its
quantitation would have to be tailored specifically to local goals. The au-
thors do not necessarily advocate either quantitation of the guidance of para-
graph B78 or its quantitation in the following manner since the guidance con-
siderations may be complexly interactive. The approach described below is the
initial approach tentatively selected by Commencement Bay area authorities and
should not be construed as final Commencement Bay area guidance nor as implied
guidance or a precedent for actual LADs elsewhere.
a. Number of contaminants. If 25 percent or less of the contami-
nants of concern show total uptake from the test sediment ex-
ceeding that from the reference sediment, there is cause for
low concern. If more than 25 percent of the contaminants of
concern show total uptake from the test sediment exceeding
that from the reference sediment, there is cause for high
concern.
b. Magnitude above reference. If dredged material produces total
uptake of contaminants of concern 10 or less times higher than
that from the reference sediment, there is cause for low~con-
cern. If dredged material produces total uptake more than
10 times that from the reference sediment, there is cause for
high concern.
£. Toxicological importance. If the contaminants of concern
showing total uptake exceeding reference levels are rank 1-3
in Table C3, there is cause for low concern. If the bioac-
cumulated contaminants are ranked 4-6 in Ta'ble C3, there is
cause for high concern. (Unranked contaminants of concern
are cause for moderate concern unless there is additional
evidence to reasonably warrant a different level of concern.)
d. Number of sampling sites. If 50 percent or less of the sedi-
ment sampling sites in the dredging area being evaluated pro-
duce bioaccumulation exceeding the reference sediment, there
is cause for low concern. If more than 50 percent of the sed-
iment sampling sites produce bioaccumulation exceeding the
reference sediment, there is cause for high concern. (If a
single composite sample from the dredging area is tested,
this factor drops from consideration.)
Findings of low, concern in all factors lead to a DECISION OF NO RESTRICTIONS
required to protect from possible adverse impacts of dredged material disposal
B65
-------
in the upland environment. A finding of moderate or high concern in one or
more factors leads to a DECISION OF RESTRICTIONS required to protect from pos-
sible adverse contaminant impacts of dredged material disposal in the upland
environment. Some potentially appropriate restrictions of such cases are
discussed in paragraphs 81-92 and 96.
Human Exposure Evaluation
B80. There are recommended limitations on the amount of sewage sludge
metals that can be applied to agricultural crop land as related to background
metal levels (Tables C9 and CIO). Based on these limitations, a potential for
human exposure of contaminants of concern in the test sediment under upland
disposal environments could be evaluated by comparing total bulk chemical anal-
ysis data for the test sediment/dredged material to the values for soil inges-
tion in Table CIO. Soil ingestion could result from breathing dust and/or ac-
tual contact and intake of soil such as is the case with a child playing on
the ground. In England surface soil contaminant limitations for human expo-
sure are based on a child eating a handful of soil while playing on the
ground. While this approach to human exposure assessment may be crude and
oversimplified, it can give some perspective to the potential human exposure
that is evaluated for agricultural cropland and in Europe. This evaluation
for human exposure could be used as guidance to the LAD for allowing the public
access to the disposal site. In addition, the LAD might be to limit agricul-
tural production of edible crops on test sediment/dredged material containing
metal concentrations in excess of that allowed for sewage sludge application
(Table C9). Two conditions can result (Figure B8):
a. Concentrations of contaminants of concern in the test sediment/
dredged material are less than or equal to those specified in
Tables C9 and CIO. This leads to a DECISION OF NO RESTRICTIONS
required to protect against contaminant impacts due to human
exposure to the test sediment/dredged material.
b. Concentrations of any contaminants of concern in the test
sediment/dredged material is greater than that specified in
Tables C9 and CIO. This leads to a DECISION FOR RESTRICTIONS
required to protect against contaminant impacts due to human
exposure to the test sediment/dredged material. Some poten-
tially appropriate restrictions are described in para-
graphs 81-92 and 96.
B66
-------
HUMAN
EXPOSURE
w
•TEST < TABULATED VALUE ( TABLES C9 & CIO )-
NO RESTRICTIONS
-TEST > TABULATED VALUE ( TABLES C9 & CIO )-*H RESTRICTIONS
Figure B8. Flowchart for declsionmaking for potential human exposure
-------
B81. Commencement Bay area authorities have tentatively decided to make
the LAD that dredged material containing contaminant concentrations in the
range of background levels for US cropland (Table C9) leads to a DECISION FOR
NO FURTHER TESTING and NO RESTRICTIONS to protect from possible adverse con-
taminant impacts of dredged material disposal in the upland environment.
Dredged material containing contaminant concentrations greater than the range
of background levels for US cropland (Table C9) leads to a DECISION FOR FURTHER
EVALUATION by conducting additional tests.
B68
-------
APPENDIX C: RELATED INFORMATION AND DATA TABLES
Table Number Topic
Cl Action Levels for Contaminants in Aquatic Organisms for Human
Consumption
C2 US Environmental Protection Agency (EPA) Water Quality Criteria
for the Protection of Aquatic Life
C3 Ranking of Toxicological Importance of Contaminants Based on
EPA 24-hr Average (Chronic) Water Quality Criteria for the
Protection of Fresh Water or Saltwater Aquatic Life
C4 Contaminant Concentrations in Drinking Water Standards
C5 Demonstrated Effects of Contaminants on Plants
C6 Maximum Recommended Application of Municipal Sludge-Applied
Metals to Medium-Textured Cropland Soils to Prevent
Phytotoxicity
C7 Action Levels for Various Heavy Metals and Pesticides in Plants
and Foodstuffs
C8 Additional Action Levels for Contaminants in Foodstuffs Used by
Other Countries
C9 Background Levels and Allowable Applications of Several Heavy
Metals for US Cropland Soils
CIO Recommended or Regulated Limitations on Potentially Toxic
Constituents in Surface Soils
NOTE: All references cited in this appendix are included in the list of
references that follows the main text.
Cl
-------
Table Cl
Action Levels for Contaminants in Aquatic
Organisms for Human Consumption
Chemical
Food
Aldrin
Antimony
Arsenic
Fish and shellfish
All nonspecified foods
(including seafood)
Fish, crustacea,
molluscs
Action Level*
(ing/kg wet
weight edible
portions)
0.3
Maximum
Concentration**
(mg/kg wet
weight edible
portions)
1.5
1.0
Cadmium
Chlordane
Copper
DDT, DDE, TDE
Dieldrin
Endrin
Heptachlor, heptachlor
epoxide
Hexachlorocyclohexane
(Benzene
hexachloride)
Kepone
Lead
Fish
Molluscs
Fish 0.3
Molluscs
All nonspecified foods
(including seafood)
Fish 5.0t
Fish and shellfish 0.3
Fish and shellfish 0.3
Fish and shellfish 0.3t
Frog legs
Fish and shellfish '0.3
Crabmeat 0.4
Molluscs
All nonspecified foods
(including seafood)
(Continued)
0.2
1.0
70.0
10.0
0.5
2.5
1.5
* United States Food and Drug Administration (FDA) Action Levels for
Poisonous or Deleterious Substances in Human Food.
** Australian National Health and Medical Research Council Standards for
Metals in Food, May 1980.
t Action level is for these chemicals individually or in combination. How-
ever, in adding concentrations, do not count any concentrations below the
following levels:
Minimum level (mg/kg)
Chemical
DDT, DDE, TDE
Heptachlor, heptachlor epoxide
0.2
0.3
-------
Table Cl (Concluded)
Maximum
Action Level Concentration
(mg/kg wet (mg/kg wet
weight edible weight edible
Chemical Food portions) portions)
Mercury Fish, Crustacea, 0.5
molluscs
Methylmercury Fish, shellfish, 1.0
other aquatic
animals
Mirex Fish 0.1
PCB (total) Fish and shellfish 2.0tt
Selenium All nonspecified foods 1.0
(including seafood)
Tin Fish 50.0
Toxaphene Fish 5.0
Zinc Oysters 1,000.0
All nonspecified foods 150
(including seafood)
tt This is not an action level but a tolerance limit established through the
rulemaking process.
-------
Table C2
US Environmental Protection Agency (EPA) Water Quality Criteria for
the Protection of Aquatic Life. Federal Register, Vol 45,
No. 231, Friday
..November 28, 1980, pp 79318-79357
Chemical
Aldrin
Arsenic (total trivalent)
Cadmium
50 mg/Ji CaCO
100 mg/£ CaCO
200 mg/H CaCOj
Chlordane
Chromium (total
trivalent)
50 mg/£ CaCO
100 mg/£ CaCO-
200 mg/£ CaCO^
Chromium (total
hexavelent)
3
Copper
50 mg/Ji CaCO
100 mg/£ CaCO-
200 mg/JZ, CaCO^
Cyanide (free)
Dieldrin
DDT
TDE
DDE
Endosulfan
Endrin
Heptachlor
Criterion for Protection
Saltwater •
Maximum
24-hr avg at any time
(chronic) (acute)
1.3
—
4.5 59
0.0040 0.09
__ __
18 1,260
4.0 23
—
0.0019 0.71
0.0010 0.13
—
—
0.0087 0.034
0.0023 0.037
0.0036 0.053
of Aquatic
Life, u8/Jl
Fresh Water
24-hr avg
(chronic)
—
—
0.012
0.025
0.051
0.0043
—
—
0.29
5.6
3.5
0.0019
0.0010
—
—
0.056
0.0023
0.0038
Maximum
at any time
(acute)
3.0
440
1.5
3.0
6.3
2.4
2,200
4,700
9,900
21
12
22
43
52
2.5
1.1
—
—
0.22
0.18
0.52
(Continued)
-------
Table C2 (Concluded)
Criterion for Protection of Aquatic Life, Mg/i
Chemical
Saltwater
Fresh Water
Lindane
Lead
50 mg/i CaCO
100 mg/i CaCO
200
Mercury
Nickel5
50 mg/i CaCO
100 mg/i CaCO-
200 mg/i CaCO^
PCB (total)
Selenium
inorganic selenite
Silver6
50 mg/i CaCO
100 mg/i CaCO-
200 mg/i CaCOg
Toxaphene
Zinc7
50 mg/i CaCO
100 mg/i CaCO-
200 mg/i
24-hr avg
(chronic)
0.025
7.1
0.030
54
58
Maximum
at any time
(acute)
0.16
3.7
140
0.030
410
2.3
0.070
170
24-hr avg
(chronic)
0.080
0.75
3.8
20
0.00057
56
96
160
0.014
35
0.013
47
Maximum
at any time
(acute)
2.0
74
170
400
0.0017
1,100
1,800
3,100
0.014
260
1.2
4.1
13
1.6
180
320
570
Note: Criteria for some metals in fresh water are hardness-dependent and are
derived from the following equations, where h is hardness in mg/i as
e is the natural logrithm base.
24-hr avg
CaCO , and
Metal
Cadmium
Chromium (total
trivalent)
Copper
Lead
3Nickel
'Silver
7 Zinc
1.05 (In h) - 8.53
(main table)
a2.35 (In h) - 9.48
0.76 (In h) + 1.06
0.83 (In h) + 1.95
Maximum at any time
1.05 (In h) - 3.73
e
1.08 (In h) + 3.48
e
g0.94 (In h) - 1.23
1.22 (In h) - 0.47
e
g0.76 (In h) + 4.02
1.72 (In h) - 6.52
(main table)
— indicates criterion not established
-------
Table C3
Ranking of Toxicological Importance of Contaminants Based on
EPA 24-hr Average (Chronic) Water Quality Criteria for
Rank
6
5
4
3
2
1
Protection of Fresh Water
Fresh Water
Criterion
Range
yg/£* Contaminant**
0.0001-0.001 Mercury
0.001-0.01 DDT
Dieldrin
Endrin
Heptachlor
Chlordane
0.01-0.1 Toxaphene
PCB (total)
Cadmium
Endosulfan
Lindane
0.1-1.0 Chromium
1-10 Cyanide
Lead
Copper
10-100 Selenium
Zinc
Nickel
or Saltwater Aquatic Life
Saltwater
Criterion
Range
Rank ug/£
6 0.0001-0.001
5 0.001-0.01
4 0.01-0.1
3 0.1-1.0
2 1-10
1 10-100
the
Contaminant **
t
DDT
Dieldrin
Endrin
Heptachlor
Chlordane
Endosulfan
Mercury
PCB (total)
t
Copper
Cadmium
Nickel
Selenium
Zinc
* For fresh water, metals are ranked according to the criterion at a
hardness of 100 rag/£ CaCO .
** Within each rank, contaminants are listed in order of increasing criterion
values.
t No saltwater chronic criteria fall in this range.
-------
Table C4
Contaminant Concentrations in Drinking Water Standards
Parameter, mg/A
unless otherwise noted
Arsenic
Barium
Cadmium
Chromium
Lead
Mercury
Selenium
Silver
Fluoride
Nitrate (as N)
Endrin
Lindane
Methoxychlor
Toxaphene
2,4-D
2,4,5-TP Silvex
Trihalomethanes
Turbidity (JU)
Coliform bacteria -.membrane
filter test (#/100 m£)
Gross alpha (pCi/£)
Combined Radium 226 and
Radium 228
Beta and photon particle
activity (Mrem/yr)
Sodium
Chloride
Color (units)
Copper
Corrosivity
Foaming agents
Iron
Manganese
Odor (threshold No.)
pH (units)
Sulfate
Total dissolved solids
Zinc
Drinking
Federal
0.05
1.0
0.010
0.05
0.05
0.002
0.01
0.05
1.4-2.4
10.0
0.0002
0.004
0.1
0.005
0.1
0.01
0.1
1.0
1.0
15.0
5.0
4.0
Monitor
250.0
15.0
1.0
Noncdrroslve
0.5
0.3
0.05
3.0
6.5-8.5
250.0
500.0
5.0
Water Standards
State of Washington
0.05
1.0
0.010
0.05
0.05
0.002
0.01
0.05
1.4-2.4
10.0
0.0002
0.004
0.1
O'.OOS
0.1
0.01
0.1
1.0
1.0
15.0
5.0
4.0
250.0
250.0
15.0
1.0
Noncorrosive
0.5
0.3
0.05
3.0
6.5-8.5
250.0
500.0
5.0
-------
Table C5
Demonstrated Effects of Contaminants on Plants
Plant Growth
Contaminant
As
B
Cd
Co
Cr , Oxides
Cu
F
Fe
Mn
Mo
Ni
Pb
Se
V
Zn
Normal*
0.1-1
775
0.1-1
0.01-0.3
0.1-1
3-20
1-5
30-300
15-150
0.1-3.0
0.1-5
2-5
0.1-2
0.1-1
15-150
"Critical"
Content**
mg/kg leaves
__
—
8
— —
20
—
—
—
—
11
—
—
200
10%** Yield
Reduction
mg/kg leaves
—
—
15
^^
20
—
—
—
—
26
—
—
—
290
25%t Yield
Reduction
mg/kg leaves
—
--
Varies
— —
20-40
—
—
500
—
50-100
—
—
—
500
Phytotoxic*
3-10
75
5-700
25-100
20
25-40
—
—
400-2,000
100
500-1,000
—
100
10
500-1,500
* From Chancy, R. L. (1983).
** From Davis, Beckett, and Wollan (1978), Davis and Beckett (1978),
Beckett and Davis (1977).
t From Chaney et al. (1978).
-------
Maximum
Sludge
Table C6
Recommended Application of Municipal
j-Applied Metals tb
Cropland Soils to Prevent
Medium-Textured
Phytotoxicity*
Maximum Application
Contaminant
Pb
Zn
Cu
Ni
Cd
kg/ha
1,000
560
280
112
11.2
Ib/a
891
446
223
111
4.5
mg/kg
500**
250
125
62
2.5
Note: Soil bulk density 1.33; potentially acidic soil.
Recommended limits to prevent yield reduction in
sensitive vegetable crops at pH £ 6.2 , or most
crops and cover crops at pH £ 5.5 .
* USEPA, USDA, USFDA (1980).
** Maximum allowable Pb content in soil for human
child exposure as related to direct soil in-
gest ion in the United Kingdom and in the United
States.
-------
Table C7
Action Levels for Various Heavy Metala and Pesticides in Plants and Foodstuffs
Substance
Commodity
Aflatoxin
Aldrin and Dleldrin
Arsenic
Benzene Hexachloride (BHC)
Cadmium
Feeds
Brazil Nuts
Peanuts
Pistachio nuts
Grain (raw cereal)
Rice (in the husk)
Animal feed
Vegetables
Artichokes
Lettuce and carrots
Fruits
Melons
Sugarbeet pulp
Non-pulpy black-current nectar
Fructose
Cocoa powders and dry
cocoa-sugar mixtures
Grain (animal feed)
Grain (human food)
Vegetables
Fruits
Provisional weekly tolerance
intake for humans
Data
Source*
1
1
1
1
2
2
1
2
1
2
1
1
1
3
3
3
1
1
1
1
Action Level
20.0 ppb
20.0 megs/kg
20.0 megs/kg
20.0 megs/kg
0.02 mg/kg
0.02 mg/kg
0.03 ppm
0.1 mg/kg
0.05 ppm
0.1 mg/kg
0.05 ppm
0.15 ppm
0.1 ppm
0.2 mg/kg
1 mg/kg
1 mg/kg
0.1 ppm
0.1 ppm
0.5 ppm
0.5 ppm
0.0067-
0.0083 rag/kg
body weight
Type of
Limit**
PRL
T
T
PRL
Referencett
CPA 7126.33
CPG 7112.07
CPG 7112.02
CPG 7112.08
CPG 7126.27-A
CPG 7120.23-A
CPG 7120.23-A
CPG 7120.23-A
CPG 7126.27-A
CAC/RS 101-1978
CAC/RS 102-1978
CAC/RS 105-1978
CPG 7126.27-B
CPG 7120.23-B
CPG 7120.23-B
CPG 7120.23-B
(Continued)
* Data source:
1 • FDA action levels for poisonous or deleterious substances in human food and animal feed,
2 • FAO/WHO guide to Codex Maximum Limits for Pesticide Residues,
3 - List of maximum levels recommended for contaminants by the Joint FAO/WHO Codex Alimentarlus Commission. Joint FAO/WHO food
standards programme Codex Alimentarlus Commission CAC/FAL 4-1978.
** Type of limit:
CPG - Compliance Policy Guidelines,
TT - Temporary Codex Tolerance,
T - Codex Tolerance, and
PRL - Practical Residue Limit.
t Step - "Step" In the procedure for the elaboration of Codex Maximum Limits for Pesticide Residue given in the FAO/WHO Gude to CODEX M.
tt1 Reference - Refers to CPG number.
(Sheet 1 of 5)
-------
Table C7 (Continued)
Substance
Chlordane
Copper
Crotalarla Seeds
Dibromochloropropane (0BCP)
DDT, DDE, and TDE
Endrin
Commodity
Root and tuber vegetables
Sugar beet
Leafy vegetables
Stem vegetables
Legume vegetables
Fruiting vegetables
Citrus fruits
Assorted fruits
Pineapple
Passion fruit
Pome fruit
Stone fruit
Small fruits and berries
Cottonseed oil, crude
Cottonseed oil, edible
Linseed oil, crude
Soya bean oil, crude
Soya bean oil, edible
Grain, animal feed
Nuts
Non-pulpy black-current nectar
Fructose
Cocoa powders and dry
cocoa-sugar mixtures
Edible acid casein
Edible caselnates
Grains and feeds
Raw agricultural commodities
Grain, animal feed
Grain, human food
Cocoa beans
Vegetables
Fruits
Oilseed meal, animal feed
Cottonseed oil, crude
Cottonseed oil, edible
Linseed oil, crude
Data
Source
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
1
2
3
3
3
3
3
1
1
1
1
1
1
1
1
2
2
2
Action Level
0.3 mg/kg
0.3 mg/kg
0.2 mg/kg
0.2 mg/kg
0.02 mg/kg
0.1 mg/kg
0.02 mg/kg
0.1 mg/kg
.0.1 mg/kg
0.1 mg/kg
0.02 mg/kg
0.02 mg/kg
0.1 mg/kg
0.1 mg/kg
0.02 mg/kg
0.5 mg/kg
0.5 mg/kg
0.02 mg/kg
0.1 ppm
0.1 mg/kg
5 mg/kg
2 mg/kg
50 mg/kg
5 mg/kg
5 mg/kg
Avg of one whole
seed /pound
0.05 ppm
0.5 ppm
0.5 ppm
2.0 ppm
0.05 ppm
0.05 ppm
0.03 ppm
0.1 mg/kg
0.02 mg/kg
0.5 mg/kg
Type of
Limit
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
—
—
__
—
—
—
—
—
—
—
—
—
—
—
—
T
T
T
Step
6
9
6
6
9
9
9
6
9
6
9
9
6
9
9
9
9
9
—
—
__
—
—
—
—
—
—
__
—
—
—
—
—
9
9
9
Reference
71(1)
—
71(1)
71(1)
—
—
—
.
—
72(1)
—
—
—
—
—
—
—
—
CPG 7126.27-C
—
CAC/RS 101-1978
CAC/RS 102-1978
CAC/RS 105-1978
18th sesslons-1976
App. VI, CS 5/70
18th sesslon-1976
CPG 7126.15
CPG-7120.23-E
CPG 7126. 27-D
CPG 7120.23-D
CPG 7120.23-D
CPG 7120. 23-E
CPG 7 120. 23-E
CPG 7126. 27-E
__
—
—
(Continued)
(Sheet 2 of 5)
-------
Table C7 (Continued)
Substance Commodity
Endrln (Continued) Soya bean oil, crude
Soya bean oil, edible
Vegetable oils and fats
Nuts
Fenthion Root and tuber vegetables
Bulb vegetables
Squash
Ground red peppers
Leafy vegetables
Brasslca leafy vegetables
Legume vegetables
Assorted fruits
Bananas
Stone fruits
Plums
Small fruits and berries
Grapes
Cereal grains
Oilseed
Hepcachlor Vegetables
Vegetables
Tomato
Carrot
Sugar beet
Fruits
Fruits
Grain, animal feed
Grain, human food
Raw cereal
Soya bean oil, crude
Soya bean oil, edible
Cottonseed
Iron Non-pulpy black currant nectar
Edible acid casein
Edible caaelnates
Data
Source
2
2
1
2
2
2
2
1
2
2
2
2
2
2
2
2
2
2
2
2
1
2
2
2
1
2
1
1
2
2
2
2
3
3
3
Action Level
0.5 mg/kg
0.02 mg/kg
0.3 ppm
0.1 mg/kg
0.1 mg/kg
0.1 mg/kg
0.2 mg/kg
0 . 3 ppm
2.0 mg/kg
1.0 mg/kg
0.1 mg/kg
2.0 mg/kg
1.0 mg/kg
0.2 mg/kg
0.1 mg/kg
0.2 mg/kg
0.5 mg/kg
0.1 mg/kg
0.1 mg/kg
0.05 mg/kg
0.05 ppm
0.02 mg/kg
0.2 mg/kg
0.05 mg/kg
0.05 ppm
0.01 mg/kg
0.03 ppm
0.03 ppm
0.02 mg/kg
0.5 mg/kg
0.02 mg/kg
0.02 mg/kg
- 15 mg/kg
20 mg/kg
50 mg/kg
Type of
Limit
T
T
—
T
TT
TT
TT
—
TT
TT
TT
TT
TT
TT
TT
TT
TT
TT
TT
PRL
—
PRL
PRL
PRL
—
PRL
—
—
PRL
PRL
PRL
PRL
Step
9
9
—
6
3
3
6
—
6
6
3
6
3
6
3
3
6
6
6
9
—
9
9
9
—
9
—
—
9
9
9
9
Reference
__
—
CPG-7126.27-E
72 (1)
JMPR 1977
JMPR 1977
—
CPG 7120. 23-G
—
—
—
—
JMPR 1977
—
JMPR 1977
JMPR 1977
—
—
—
—
7120.23-H
—
__
—
CPG 7120.23-H
—
CPG 7126.27-F
CPG 7120.23-H
__
—
—
CAC/RS 101-1978,
App. V., CX
5/70
18th sesslon-1976
App. VI, CX 5/70
18th sesslon-1976
Kelthane
Kepone
Animal feed
0.5 ppm
(Continued)
CPG 7126.27G
(Sheet 3 of 5)
-------
Table C7 (Continued)
Substance
Lead
Lindane
Mercury
Methyl alcohol
Nltrosodimethylamlne (NDMA)
Commodity
Non-pulpy black currant nectar
Cocoa powders and dry
cocoa-sugar mixtures
Edible acid casein
Edible caseinates
Vegetables
Root and tuber vegetables
Leafy vegetables
Brasslca vegetables
Stem vegetables
Legume vegetables
Peas
Assorted fruits
Small fruits and berries
Cranberries
Fruits
Grain, animal feed
Grain, human food
Wheat (pink kernals only)
Provisional tolerable weekly
intake for humans
Imported brandy
Barley malt
Malt beverages
Data
Source
3
3
3
3
1
2
2
2
2
2
2
2
2
2
1
1
1
1
3
I
1
1
Action Level
0.3 mg/kg
2 mg/kg
2
2
0.5 ppm
0.05 mg/kg
0.2 mg/kg
0.5 mg/kg
0.5 ng/kg
0.1 mg/kg
0.1 mg/kg
0.5 mg/kg
0.5 mg/kg
0.3 mg/kg
0.5 ppm
0.1 ppm
0.1 ppm
1.0 ppm
0.005 mg total
Hg/kg body
weight
0.0033 mg
methylmercury/
kg body weight
0.35 percent
1 . 0 ppm
0.5 ppm
Type of
Limit
__
—
—
—
—
T
T
T
T
T
T
T
T
T
—
—
—
—
—
—
—
Step
__
—
«
—
—
5
3
3
5
9
5
9
3
5
—
—
—
—
—
—
—
Reference
CAC/RS 101-1978
CAC/RS 105-1978
App. V, CS 5/70
18th session
App. VI, CS 5/70
18th session
CPG 7120.23-J
JMPR 1975
JMPR 1975
JMPR 1975
JMPR 1975
109 (1)
JMPR 1975
110 (1)
111 (5)
CPG 7120.23-J
CPG 7126. 27-H
CPG 7120.23-J
CPG 7104.05
CPG 7119.09
CPG 7104.07
CPG 7101.07
Paralytic shellfish toxin
Polbrominated Biphenyls (PBB's)
Animal feed
0.05 ppm
A review of Con-
gressman W. M.
Brodhead's peti-
tion to reduce
FDA action levels
for PBB's in food
July 27, 1977.
(Continued)
(Sheet 4 of 5)
-------
Table C7 (Concluded)
Substance
Polychlorlnated Biphenyls
(PCB's)
Commodity
Tin
Toxaphene
Zinc
Paper food-packaging material
intended for or used with
human food, finished animal
feed, and components In-
tended for animal feeds
Canned fruit cocktail
Canned mature processed peas
Canned tropical fruit salad
Non-pulpy black currant nectar
Animal feed, processed
Vegetables
Fruits
Non-pulpy black currant nectar
Data
Source
Action Level
0.10 ppm
Type of
Limit
Step
250 mg/kg
250 mg/kg
250 mg/kg
150 mg/kg
0.5 ppm
1.0 ppm
1.0 ppm
5 mg/kg
Reference
21 CFR 109.30 (a)
(9) and 509.30
(a) (9) tolerance
used stayed on
8-24-73 (38 FR
22794) 21 CFR
109.6 (d) and
509.6 (d)
CAC/RS 78-1974
CAC/RS 81-1976
CAC/RS 99-1978
CAC/RS 101-1978
CPG 7126.27-1
CPG 7120.23-L
CPG 7120.23-L
CAC/RS 101-1978
(Sheet 5 of 5)
-------
Table C8
Additional Action Levels for Contaminants in Foodstuffs Used by Other Countries
Source
Britain
World Health
Organization (WHO)
Dutch
Dutch (unofficial)
European Economic
Community
FDA (as of Sep 82)
Contaminant
Pb
Pb
Cd
Cu
Cd
Pb
Hg
PBB
Various
pesticides
Commodity
All foods
Root vegetables
Cereal
Leafy vegetables
Root vegetables
Leafy vegetables
Potatoes, cereal
Animal feed
Single animal feed
Mixed animal feed
Roughage
Single animal feed
Mixed animal feed
Roughage
Wheat seed
Animal feed
Vegetables, grains,
and feeds
Content, mg/kg
1.0 (fresh wt)
0.1 (fresh wt)
0.1 (fresh wt)
1.2 (fresh wt)
0.05 (fresh wt)
0.1 (fresh wt)
0.1 (fresh wt)
20.0 (dry wt)
0.5 (dry wt)
1.0 (dry wt)
1-2 (fresh wt)
10.0 (dry wt)
5.0 (dry wt)
40.0 (fresh wt)
1.0 (dry wt)
0.5 (dry wt)
0.03-0.1
References
M.A.F.F., 1972
WHO, 1972
WHO, 1972
DMAFCMN, 1973
European Community, 1974
Van Driel et al., 1982
FDA, 1982
-------
Table C9
Background Levels and Allowable Applications of Several Heavy Metals
for US Cropland Soils (from
Concentration
Holnigren et al.
in
Surface Soils (mg/kg)
Metal
Pb
Zn
Cu
Ni
Cd
PH
5 percentile median
4.0 11
7.3 54
3.7 19
3.8 19
0.035 0.20
4.6 6.1
95 percentile
27
129
96
59
0.78
8.1
1985 and Table
No Effect
Allowed
Addition*
kg/ha
1,000
500
250
125
5
.C6)
Median +
Allowed
Application
mg/kg
511
304
144
82
2.7
* Allowed application is mixed into the 0-15 cm (0-6 in.) surface layer
of soil.
Table CIO
Recommended or Regulated Limitations on Potentially
Toxic Constituents in Surface (0-15 cm) Soils
Basis for
Limitation
Soil Ingestion
Plant Uptake
Phytotoxicity
Leaching
Contaminant
Pb
Hg
PCBs etc.
Cd
Zn
Cu
Ni
Co
Cr (VI)
Soil
Concentration
500 mg/kg
5 mg/kg
2.0 mg/kg
2.5 mg/kg (PH 5.5)
250 mg/kg
125 mg/kg
62 mg/kg
62
0.05 mg/«,
Reference
EPA, 1977
Fries, 1982
EPA, 1979
Logan and Chaney, 1983
EPA Drinking Water
Standard Table C4
-------
APPENDIX D: PROCEDURES FOR AND EXAMPLES OF MIXING ZONE CALCULATIONS
Page
Volume of Dilution Water Dl
Shape of Mixing Zone D4
Discrete discharges D4
Continuous pipeline discharges D7
Sample Computations Dll
Discrete discharges Dll
Continuous pipeline discharge D12
Evaluation of calculations D13
Selected Bibliography D1A
Sediment A—Aquatic Disposal Calculation of Hypothetical
Mixing Zone for PCB D15
Assumptions D15
Calculations D15
Description D16
Sediment B—Upland Disposal Effluent Calculation of
Hypothetical Mixing Zone for Crassostrea Toxicity
D17
Assumptions D17
Calculations D17
Description D18
Sediment B—Upland Disposal Surface Runoff Calculation of
Hypothetical Mixing Zone for PCB D19
Assumptions D19
Calculations D19
Description D20
Sediment C—Upland Disposal Effluent Calculation of
Hypothetical Mixing Zone for PCB D21
Assumptions D21
Calculations D21
Description D22
NOTES: Alphanumeric identification of pages, paragraphs, and figures was used
in the appendices to distinguish them from the simple numbers used as
identification of main-text paragraphs, figures and tables. Thus ref-
erences to simple numbers in the appendices refer to similarly numbered
items in the main text.
Mixing zone procedures given in paragraphs D1-D36 were taken from
Environmental Effects Laboratory (1976).
All references cited in this appendix are included in the list of ref-
erences that follows the main text.
Dl
-------
APPENDIX D: PROCEDURES FOR AND EXAMPLES OF MIXING ZONE PROCEDURES
Volume of Dilution Water
Dl. A mixing zone is that volume of water at a disposal site required to
dilute contaminant concentrations associated with a discharge of dredged mate-
rial to an acceptable level. In order to calculate the volume of disposal
site water required for a specific proposed discharge, it is first necessary
to perform the elutriate test described on paragraph 31 of the main text to
determine the concentration of the critical constituents of greatest concern
in the standard elutriate and in disposal site water.
D2. The next step in determining the volume of the mixing zone is the
derivation of an expression for the volume of disposal site water required to
dilute to an acceptable level the concentration of a critical constituent in
one unit volume of standard elutriate resulting in a dilution factor D. Since
the mass of the constituent of interest in one volume of standard elutriate is
(1) (Ce), the mass of the constituent in D volumes of disposal site water is
(D)(Ca), and the total volume is (D + 1), the resultant concentration can be
determined. However, if rather than solving for the resultant concentration,
one prescribes its values such that a desired water-quality standard is satis-
fied, then the expression below can be solved for the volume of disposal site
water necessary to achieve such a dilution.
C - C
D = (Di)
where
D = dilution factor required to dilute concentration of constituent of
interest to a concentration equal to the numerical standard C ,
S
vol/vol
C = concentration of constituent of interest in standard elutriate, mg/fc
C = concentration of constituent of interest in disposal site water,
3.
mg/i
C = numerical standard for constituent of interest, mg/£
S
D2
-------
°3. The total volume of water necessary to dilute a discharge of dredged
material to acceptable levels is equal to the volume calculated in equation Dl
times the total volume of dredged material. This can be expressed as:
M - D Vd (D2)
where
M = required volume of disposal site water, cu yd
D = dilution factor required to dilute concentration of constituent of
interest to a concentration equal to the numerical standard C ,
s
vol/vol
V, = volume of dredged material, cu yd
D4. When using this approach to calculate the necessary volume of dilu-
tion water, the following recommendations and specifications should be
considered:
a. Acute toxicity criteria rather than chronic toxicity criteria
should be used in equation Dl to calculate the mixing volume. The justifica-
tion for this recommendation is that dredged material disposal is an intermit-
tent short-term event and perturbations resulting from disposal activities
would not be expected to persist for the lifetime of an organism. Thus, the
use of chronic toxicity criteria, based on long-term exposure, would be tech-
nically inappropriate.
b. In using standards to calculate the volume of a mixing zone,
consideration should be given to the basis of the standards. For example, the
most stringent standards for iron and manganese are based on aesthetic con-
siderations. Section 230.5(b)(l) of the Register gives consideration to dis-
charging near municipal water intakes; therefore, iron and manganese standards
that are used should reflect the toxicological and other properties of these
metals rather than aesthetic properties if these metals are deemed critical
constituents.
c. If the elutriate test concentration C is less than or equal to
the numerical standard C , no calculation is necessary since no dilution is
S
necessary.
d. If the elutriate test concentration C is greater than the
numerical standard C and the proposed disposal site water concentration C is
S 3.
D3
-------
less than the numerical standard C , the required dilution volume can be cal-
s
culated as described above.
e. If the elutriate test concentration C is greater than the pro-
posed disposal site water concentration C and the proposed disposal site
SL
water concentration C is greater than or equal to the numerical standard C ,
a s
the standard cannot be achieved by dilution. Some other procedure will have
to be used to evaluate the proposed discharge activity. One possible method
would be to use appropriate bioassays (Appendix A).
Shape of Mixing Zone
D5. After calculating the required volume M of disposal site water that
would be necessary for diluting the proposed discharge, the next step in
implementing the mixing zone concept is to characterize the shape associated
with the dilution volume. This can be accomplished by defining relatively
simple three-dimensional geometric shapes for use with specified types of
discharges and discharge conditions.
Discrete discharges
D6. The general shape with greatest apparent applicability to discrete .
discharge operations is that of a conical frustum whose volume M is defined
by:
(D3)
where
d = height of frustum
A, = area of lower base of frustum
A = area of upper base of frustum
D7. Five different combinations of disposal operations and ambient cur-
rent conditions are considered for discrete discharge operations (Figure Dl).
Each combination can be described by a volumetric and a surface area equation
that will define the mixing zone for a proposed discharge operation. The var-
iables used in equations D4-13 in Figure Dl are defined as follows:
r = radius of initial surface mixing
d = depth of water at proposed disposal site
-------
o
Wn
PROJECTED SURFACE AREA
(D4)
VOLUME
(D5)
ELEVATION M=-J«VI TWIT I
A. STATIONARY DISCHARGE WITH NEGLIGIBLE CURRENT
VT
PROJECTED SURFACE AREA
PLAN
r\
VOLUME
ELEVATION J
B. MOVING DISCHARGE WITH NEGLIGIBLE CURRENT
PROJECTED SURFACE AREA
r) (D7)
(D9)
ELEVATION
C. STATIONARY DISCHARGE WITH PREVAILING CURRENT
^~"P\ - ~^~T
"I \ / \
I it '
PROJECTED SURFACE AREA
(D10)
PLAN
VOLUME
(Dll)
ELEVATION
D. MOVING DISCHARGE WITH PREVAILING CURRENT
PROJECTED SURFACE AREA
* VT (fH
VOLUME
(D12)
(D13)
ELEVATION
E. MOVING DISCHARGE ACROSS PREVAILING CURRENT
THE VARIABLES USED IN THE EQUATIONS IN THIS FICURE ARC DEFINED AS FOLLOWS:
r = RADIUS OF INITIAL SURFACE MIXING
d= DEPTH OF WATER AT PROPOSED DISPOSAL SITE
R= BOTTOM RADIUS OF MIXING ZONE AREA
V= VELOCITY OF DISCHARGE VESSEL
T- TIME REQUIRED TO EMPTY VESSEL DURING DISCHARGE
V,s WATER VELOCITY AT PROPOSED DISPOSAL SITE
X = HORIZONTAL TRANSPORT DISTANCE OF DREDGED MATERIAL
Figure Dl. Project surface area and volume equations for discrete discharge operations
-------
R = bottom radius of mixing zone area
V = velocity of discharge vessel
T = time required to empty vessel during discharge
V = water velocity at proposed disposal site
w
X = horizontal transport distance of dredged material
D8. The value r is intended to approximate the initial surface mixing
that will occur at a disposal site. This value will be site specific and will
vary with the type of disposal operation. In the absence of better informa-
tion, an upper value for r can be estimated as 100 m as suggested by EPA (EPA
1973) or one-half in length of the discharge vessel.
D9. R is the radius of the bottom area of a conical frustum that defines
a volume sufficient to dilute the proposed discharge to acceptable levels. R
should be greater than or equal to the initial surface mixing radius r, since
the discharge would be expected to expand horizontally as it settles through
the water column.
D10. X is the horizontal transport distance that dredged material will
move away from the point of initial discharge as a result of water currents.
A reasonable estimate of this value can be calculated as:
„ / depth of water column \ ^ , JA_
X = I £3 —=-T =—j— I water velocity
yappropriate settling velocity I '
(D14)
ft)--
Dll. The most difficult parameter to define in equation D14 will be the
appropriate settling velocity V . The settling velocity that is used should
s
represent the average settling velocity of the discharge and not the settling
velocity of the discharge and not the settling velocity of an average size
particle in the discharge.
D12. Each volumetric equation in Figure Dl can be solved for a single
parameter R once the total volume M is specified, since other parameters
should be constant for a proposed discharge operation and a given disposal
site. The calculated R-value can then be substituted in the appropriate sur-
face area projection equation to estimate the surface area that will be influ-
enced by the proposed discharge.
D6
-------
D13. The area calculation allows one to determine whether the projected
surface area for a proposed discharge fits within the geographical limits of
the authorized disposal site (where such limits are established) and to deter-
mine the most appropriate locations for the initial dump to ensure that the
projected surface area remains within the authorized disposal site. An esti-
mate of the surface area to be influenced by a proposed discharge will also
allow one to locate the disposal site in such a manner that possible adverse
effects on other beneficial uses such as public water intakes or shell fish-
eries are avoided or minimized,
Continuous pipeline discharges
D14. The approach to be taken in calculating the necessary mixing zone
for a proposed pipeline disposal operation is similar to the discrete dis-
charge approach except that the volume of water required for dilution is
expressed as a rate of flow.
C - C
S__£ (Dl)
with all terms as defined earlier in paragraph D2. However, since the dis-
charge from a pipeline will occur at a specified rate V , the volume of ambi-
ent site water per unit time that would be required to dilute the discharge to
acceptable levels can be defined as:
VA - V
where
V = volume of site water/unit time required for dilution, cfs
a
V = rate of disposal from pipeline, cfs
P
C = elutriate test concentration, mg/A
e
C = disposal site concentration, mg/A
a
C = acceptable level to be achieved by dilution, mg/JZ.
s
D15. It is assumed that the mixing zone associated with a pipeline dis
charge will resemble the shape in Figure D2. Therefore, once the required
volume per unit time has been calculated, the next step is to determine the
D7
-------
-•*
PLAN
FRONTAL
ELEVATION
PROJECTED SURFACE AREA
VOLUME PER UNIT TIME
A= ^
(D16)
VA= LdVw
(D17)
Figure D2. Projected surface area and volume equations for continuous
pipeline discharge with prevailing current
D8
-------
dimensions of the mixing zone. The required volume per unit time can also be
expressed as:
VA - L d Vw (D18)
where
VA = required volume of water per unit time, cfs
L = width of mixing zone at time t, ft
d = depth, ft
Vw = velocity of water at disposal site, ft/sec
D16. Since the depth and water velocity are known or can be measured, the
width of the front edge of the mixing zone can be calculated as:
V
(D19)
d V
w
D17. Based on information presented by Brooks (1960), the time required
for the front edge of the mixing zone to spread laterally to the required
width L can be computed from:
t = j [0.094 L2/3 - 0.149(r2/3)] (D20*)
where
t = required time for lateral spreading, sec
L = necessary width of the front edge of mixing zone, ft
r = one-half initial width of the plume at point of discharge (radius)
of initial surface mixing), ft
A = turbulent dissipation parameter
Values for X range from 0.00015 to 0.005 with a value of 0.005 being appropri-
ate in a dynamic environment such as an estuary (Bradsma and Divoky 1976) . As
* B. Johnson and M. B. Boyd. 1975. "Mixing Zone Estimate for Interior Guid-
ance," Unpublished Memo, Mathematical Hydraulics Division, Hydraulics Lab-
oratory, US Army Engineer Waterways Experiment Station, CE, Vicksburg,
Mississippi-
D9
-------
discussed earlier, values for r will be influenced by the method of disposal
and will be site specific.
D18. The calculated time can then be used to determine the longitudinal
distance the discharge will travel as it is spreading to the required width.
This distance can be computed from:
X = V t (D21)
w
where
X = longitudinal movement of discharge, ft
V = velocity of water at disposal site, ft/sec
t = necessary time of travel, sec
D19. The results of Equations D20 and D21 can then be combined to esti-
mate the projected surface area of the proposed discharge. This area can be
computed as:
(D22)
where
2
A = surface area, ft
L = width of front edge of mixing zone, ft
r = radius of initial surface mixing, ft
X = length of the mixing zone, ft
D20. This approach will characterize a proposed discharge by defining the
volume of dilution water per unit time that will be required to achieve some
acceptable concentration at the edge of the mixing zone. Also, the length and
width (and hence the surface area) of the necessary mixing zone will be
approximated.
D21. The approach used to calculate the required mixing zone for a con-
tinuous pipeline disposal operation may also be used to calculate the required
mixing zone for a return flow from a confined disposal area. The calculations
would be the same except that the volume of flow from a confined disposal area
would be substituted for the volume of flow from a pipeline. The method
should only be applied, however, where there is a discrete discharge sources
such as a conduit or a weir.
DIG
-------
Sample Computations
D22. The following computations are presented to illustrate the mixing
zone concept as applied to two particular disposal operations: a moving dis-
crete discharge in the direction of a prevailing current (Figure Dl, Case D)
and a continuous discharge from a pipeline (Figure D2).
Discrete discharge
D23. The following input values were used in the sample computations:
Volume of dredged material V. = 4000 yd
Turbulent dissipation parameter A - 0.005
Water column depth d » 50 ft
Vessel speed V =6 ft/sec
Ambient water velocity V =2 ft/sec
A
Time to end of discharge T - 360 sec
Radius of initial surface mixing r = 25 ft
Concentration of constituent of interest
in standard elutriate C 30 mg/A
Ambient concentration C 0.1 mg/i
a
Acceptable concentration C - 0.5 mg/t,
Settling velocity V - 10 ft/sec
s
D24. The dilution factor required to dilute concentration of interest to
a concentration of equal volume C , vol/vol, would be:
s
D - °e " °s = (3° - °-5> = 73 75 (Dl)
D ~ C - C (0.5 - 0.1) /J'° ( '
s a
D25. The volume of water to dilute the discharge to acceptable levels
would be:
M = D VJ = (73.75)(4000 yd3) « 2.95 * 105 yd3
d
= 7.96 x 106 cu ft
(D2)
D26. From Figure Dl (Case D), the equation for the volume of the mixing
zone for a discrete discharge in the direction of a prevailing current is:
Dll
-------
M = j d (R2 + Rr + r2) + d V T (R + r) (DID
By setting the volume equal to 7.96 * 10 cu ft, this equation can be solved
for R, which equals 47 ft. This value can be used with the area equation in
Figure Dl (Case D):
A = I (R2 + r2) + 2 RVT + (R + r) X (DIG)
where X is solved by Equation D14:
., depth of water column , n . ..
X = —*• =-: =—; (water velocity)
settling velocity J
50 ft (2 ft/sec) = 10 ft
10 ft/sec
to arrive at the projected surface area = 208,212 sq ft.
D27. Thus, the proposed mixing zone would have the following dimensions:
Volume = 7.96 x 1Q6 cu ft
Projected surface area = 208,212 sq ft
Maximum dimensions = 2242 ft by 94 ft
This information would be used in considering the compatibility of the size of
the mixing zone required for the proposed discharge with the size of the
proposed discharge site.
Continuous pipeline discharge
D28. The following input values were used in the sample computations:
Volume of dredged material discharged
per unit time V = 44 cu ft/sec*
P
Turbulent dissipation parameter A = 0.005
Water column depth d = 10 ft
Water velocity V = 0.5 ft/sec
' w
Initial width of plume 2r = 30 ft
Ambient concentration C =0.1
* Based on pipe radius of 12 in. and discharge velocity of 14 ft/sec.
D12
-------
Elutriate test concentration C -30 mg/J,
Acceptable concentration C - 0.5 mg/Jl
D29. The required volume per unit time will be:
VA - Vp D " " (o^lS.1) - 3245 cu ft/*«<
D30. The required width of the mixing zone will be:
L' - - *649 ft
D31. The time required to achieve the lateral spread L will be:
t - ~ [(0.094M649)273 - (0.149) <15)2/3] (D20)
- 1228 sec
D32. The length of the mixing zone will be:
X - (0.5 ft/sec)(1228 sec) - 614 ft (D21)
D33. Thus the proposed mixing zone would have dimensions of:
Surface area - (30 + 649\ 614 - 208,453 sq ft
(30 + 649\
2 )
Maximum dimensions - 614 ft by 649 ft
This information would be used in considering the compatibility of the size of
the mixing zone required for the proposed discharge with the proposed dis-
charge site.
F.valuation of calculations
D34. The surface area and volumetric equations in Figures Dl and D2 were
derived on the assumption that the dredged material would spread horizontally
as it settles through the water column. Therefore, the calculated value for R
D13
-------
should be greater than r. If the calculated value for R is less than r, this
suggests that the input data is inappropriate. One possible reason for this
discrepancy is that the selected value for r may have be.en too large. In this
case, R can be recalculate using a smaller r value. (It also suggests that a
cylinder with radius r and depth d will provide sufficient water for dilution
and that the surface area projection of the mixing zone can be estimated with
r.)
D35. Another possible reason for the calculated value of R being less
than the selected value of r is the depth of the disposal site. If the depth
d is large, the mixing zone will assume the shape of an inverted cone rather
than a frustum. This also suggests that sufficient water is available for
dilution under the surface area projection defined by r.
D36. For the conditions where d is large, it may be more appropriate to
specify a maximum portion of the water column (e.g., the upper 50 ft) that can
be used for a mixing zone. Then the remaining dimensions of the mixing zone
can be calculated using the specified value rather than the actual water
column depth.
Selected Bibliography
Fetterolf, C. M., Jr. 1973. "Mixing Zone Concepts," Biological Methods for
the Assessment of Water Quality, ASTM STP 528, American Society for Testing
Materials, Philadelphia, pp 31-45.
Lee, G. F., and Plumb, R. H., Jr. 1974. "Literature Review on Research Study
for the Development of Dredged Material Disposal Criteria," Contract Report
D-74-1, US Army Engineer Waterways Experiment Station, CE, Vicksburg,
Mississippi.
Lee, G. F., et al. 1974. "Comments on U. S. EPA Proposed Criteria for Water
Quality," Occasional Paper Number 1, Institute for Environmental Sciences, The
University of Texas at Dallas, Richardson, Texas.
National Technical Advisory Committee. 1968. Water Quality Criteria, Federal
Water Pollution Control Administration, Washington, D. C.
D14
-------
Sediment A—Aquatic Disposal
Calculation of Hypothetical Mixing Zone for PCB
ASSUMPTIONS
Discrete discharge from barge moving in direction of prevailing current
(Figure Dl, case D). Barge holds 2,700 cu yd and is 190 ft long
Cg = Water-quality criterion for PCB - 0.03 ug/A
Ca = PCB concentration in disposal site receiving water - 0.005 ug/fc
C = PCB concentration in elutriate = 0.04 yg/A
3
Vd = Volume of dredged material in barge « 2,700 cu yd (72,900 ft )
r = Radius of initial surface mixing = 95 ft
d = Depth of water at disposal site «= 100 ft
V = Current velocity at disposal site (presumed to be uniform speed and
direction from surface to bottom) » 3 ft/sec
V = Velocity of barge = 6 ft/sec
T = Time to empty barge during discharge * 60 sec
V = Mass descent velocity of discharge = 9 ft/sec
s
X = horizontal transport distances as result of currents
= (d/V )V = 33 ft
CALCULATIONS
Dilution factor D required to dilute PCB in discharge to criterion
may be calculated as (Equation Dl):
" °3 0.04 - 0.03
~IT 0.03 - 0.005
s a
Volume of mixing zone M required to dilute PCB in discharge to cri-
terion may be calculated as (Equation D2):
M - DV = 0.40(72,900 ft3) = 29,160 ft
d
Bottom radius of mixing plume R may be calculated as (Equation Dll)
D15
-------
CALCULATIONS (Continued)
This is physically impossible (paragraphs D8-D9). Since R must be
greater than or equal to r , set R = r = 95 ft
Surface area projetcion A of mixing zone may be calculated as
(Equation DlO):
A = (R2 + r2) + 2RVT + (R + r)X = 103,023 ft2
Length L of surface area projection of mixing zone of configuration
of Figure Dl, case D, may be calculated as:
L = r + X + VT + R = 583 ft
Maximum width W of surface area projection of mixing zone of configu-
ration of Figure Dl, Case D, may be calculated as:
W = 2R = 190 ft
Time required to achieve dilution T, may be calculated as:
— d
T. = V L = 195 sec =3.25 min
d w
DESCRIPTION
The mixing zone required to dilute dissolved PCB in sediment A to the
acute water-quality criterion would be as follows:
• Volume = 29,160 cu ft
2
• Surface area projection = 103,023 ft
• Length = 583 ft
• Maximum width = 190 ft
• Time to achieve dilution = 195 sec =3.25 min
D16
-------
Sediment B—Upland Disposal Effluent
Calculation of Hypothetical Mixing Zone for Craesostrea Toxicity
ASSUMPTIONS
Disposal site filled with an 18-in. hydraulic dredge operating con-
tinuously, discharge over weir into waterway (Figure D2)
CB = EC50 effluent concentration = 62 percent
Ca = Effluent concentration in receiving water. = 0 percent
Cg = Effluent concentration in discharge = 100 percent
V = Rate of flow of discharge = 27 cu ft/sec
d = Depth of water at discharge site = 40 ft
Vw = Current velocity at discharge site (presumed to be uniform speed
and direction from surface to bottom) » 1.5 ft/sec
r = Radius of initial surface mixing = 24 ft
X = Turbulent dissipation parameter (paragraph D17) - 0.0005
CALCULATIONS
Dilution factor D required to dilute discharge to EC50 concentration
may be calculated as (Equation Dl):
Ce " Cs 100 - 62 ,.
Mixing zone volume per unit time V required to dilute discharge to
EC50 concentration may be calculated as (Equation D15) :
V. = V D = 13 cu ft/sec
A p
Maximum width L of mixing zone required to dilute discharge to EC50
concentration may be calculated as (Equation D19):
V.
— = n ? ft
dV
w
Time t required for plume to spread to maximum width may be calcu-
lated as (Equation D20):
t =[j 0.094L2/3 - 0.149(r2/3)l = -2,420 sec
D17
-------
CALCULATIONS (Continued)
(A negative time for spreading is physically impossible. This indicates
the necessary spreading would occur essentially instantaneously.)
Length X of mixing zone required to dilute discharge to EC50 may be
calculated as (Equation D21):
X = V t = -3,630 ft
w
(A mixing zone of negative length is physically impossible. This in-
dicates the necessary mixing would occur essentially at the point of
discharge.)
Surface area projection A of mixing zone of configuration of Fig-
ure D2 may be calculated as (Equation D22):
• -87,483 ft2
(A mixing zone of negative surface area is physically impossible. This
indicates the necessary mixing would occur essentially at the point of
discharge.)
DESCRIPTION
The mixing zone required to dilute the effluent of sediment B to the
48-hr EC50 for Crassostrea larvae would be as follows:
• Flow rate of dilution water required = 13 cu ft/sec
• Surface area projection = negligibly small
• Length = neglibi^ly small
• Maximum width = 0.2 ft
D18
-------
Sediment B—Upland Disposal Surface Runoff
Calculation of Hypothetical Mixing Zone for PCB
ASSUMPTIONS
Disposal site of 60 acres, runoff from 2-in. rainfall in 1 hr flowing
through weir and discharge pipe into a waterway (Figure D2)
QS = Water-quality criterion for PCB - 0.03 ug/£
C = PCB concentration in receiving water » 0.01 vg/A
3i
C = PCB concentration in effluent =0.50 yg/£
e °
V = Rate of flow of discharge = 121 cu ft/sec
d = Depth of water at discharge site = 40 ft
V = Current velocity at discharge site (presumed to be uniform speed
and direction from surfact to bottom) =1.5 ft/sec
r = Radius of initial surface mixing * 24 ft
X = Turbulent dissipation parameter (paragraph D16) = 0.0005
CALCULATIONS
Dilution factor D required to dilute PCB in runoff to criterion may
be calculated as (Equation Dl):
C - C
D = ce _ CS - 23.50
s ~ a
Mixing zone volume per unit time V required to dilute PCB in runoff
to criterion may be calculated as (Equation D15):
V = V D = 2,844 cu ft/sec
A p
Maximum width L of the mixing zone required to dilute PCB in runoff
to criterion may be calculated as (Equation D19):
V.
df
w
Time t required for mixing zone to spread to maximum width may be
calculated as (Equation D20):
{ [0.094 L2/3 - 0.149(r2/3)J = -32 sec
D19
-------
CALCULATIONS (Continued)
(A negative time for spreading is physically impossible. This indicates
the necessary spreading would occur essentially instantaneously.)
Length X of mixing zone required to dilute PCB in runoff to criterion
may be calculated as (Equation D21):
X = V t = -48 ft
w
(A mixing zone of negative length is physically impossible. This in-
dicates the necessary mixing would occur essentially at the point of
discharge.)
Surface area projection A of mixing zone of configuration of Fig-
ure D2 may be calculated as (Equation D22):
A - I " I " 1 X = -2,280 ft2
(A mixing zone of negative surface area is physically impossible. This
indicates the necessary mixing would occur essentially at the point of
discharge.)
DESCRIPTION
The mixing zone required to dilute PCB in sediment B upland disposal area
surface runoff to the acute water-quality criterion would be as follows:
• Flow rate of dilution water required = 2,844 cu ft/sec
• Surface area projection = negligibly small
• Length = neglibigly small
• Maximum width = 47 ft
D20
-------
Sediment C—Upland Disposal Effluent
Calculation of Hypothetical Mixing Zone for PCB
ASSUMPTIONS
Disposal site filled with 18-in. hydraulic dredge operating continu-
ously, discharge over weir into waterway (Figure D2)
Cg - Water-quality criterion for PCB - 0.03 yg/£
Ca = PCB concentration in receiving water » 0.01 ug/fc
Cg = PCB concentration in effluent =0.48 pg/£
V = Rate of flow of discharge = 27 cu ft/sec
d = Depth of water at discharge site = 40 ft
V = Current velocity at discharge site (presumed to be uniform speed
and direction from surface to bottom) »1.5 ft/sec
r = Radius of initial surface mixing » 24 ft
A = Turbulent dissipation parameter (paragraph D16) » 0.0005
CALCULATIONS
Dilution factor D required to dilute PCB discharge to criterion may
be calculated as (Equation Dl):
- 0-03 22
* >
C - C 0.03 - 0.01
s a
Mixing zone volume per unit time VA required to dilute PCB in dis
charge to criterion may be calculated as (Equation D15) :
V = v D = 473 cu ft/sec
A p
Maximum width L of the mixing zone required to dilute PCB in dis-
charge to criterion may be calculated as (Equation D19):
Time t required for plume to spread to maximum width may be calcu
lated as (Equation D20) :
t = ~ [o.094 L2/3 - 0.149(r2/3)J = -1,728 sec
D21
-------
CALCULATIONS (Continued)
(A negative time for spreading is physically impossible. This indicates
the necessary spreading would occur essentially instantaneously.)
Length X of mixing zone required to dilute PCB in discharge to cri-
terion may be calculated as (Equation D21):
X = V t = -2,592 ft
w
(A mixing zone of negative length is physically impossible. This in-
dicates the necessary mixing would occur essentially at the point of
discharge.)
Surface area projection A of mixing zone of configuration of Fig-
ure B2 may be calculated as (Equation D22):
A =
(A mixing zone of negative .surface area is physically impossible. This
indicates the necessary mixing would occur essentially at the point of
discharge.)
DESCRIPTION
The mixing zone required to dilute PCB in sediment C upland disposal ef-
fluent to the acute water-quality criterion would be as follows:
• Flow rate of dilution water required = 473 cu ft/sec
• Surface area projection = negligibly small
• Length = negligibly small
• Maximum width = 8 ft
D22
------- |