Contaminated Marine Sediments Assessment and Remediation (1989) / Chapter Skim
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Assessment of Contaminated Sediments in Commencement Bay (Puget Sound, Washington)
Assessment of Contaminated Sediments in Commencement Bay (Puget Sound, Washington)
Pages 425-439
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From page 425... ...
Ginn PTI Environmental Services ABSTRACT Sediments in Commencement Bay have been contaminated by a wide variety of inorganic and organic contaminants resulting from numerous industrial activities and pollutant discharges. Because of this contamination and associated biological effects, the area has been the subject of a Remedial Investigation/Feasibility.Study to evaluate alternatives for sediment cleanup and source control.
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From page 426... ...
Subsequently, EPA entered into a cooperative agreement with the Washington Department of Ecology to conduct a remedial investigation in Commencement Bay under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)
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From page 427... ...
However, because of the complexity of sediment contaminants and pollutant sources in Commencement Bay and the lack of available cleanup criteria for sediment contaminants, the investigation required the development of a decision-making framework to assess and prioritize contaminated sediments prior to evaluating cleanup alternatives. The development of this framework included the specification of several objectives associated with the assessment of sediment contamination: characterization of sediment contamination, sediment toxicity, and biological effects; development of criteria to def ine problem sediments ; application of the criteria to define problem areas; determination of problem chemicals for the problem areas; and prioritization of problem areas and problem chemicals relative to environmental and human health risks.
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From page 428... ...
However, quantitative relationships derived from analysis of field observations would be used, where possible, to demonstrate links between sediment contamination and biological effects. In this sense, cause/effect relationships may be implied by a preponderance of field and laboratory evidence, including the correlation of specific contaminant concentrations with the occurrence of adverse biological effects.
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From page 429... ...
CHEMICAL AND BIOLOGICAL INDICATORS The preponderance-of-evidence approach discussed above required the selection of several measurements that would serve as indicators of contamination and biological effects in Commencement Bay. To conserve costs, the objective was to select the minimum numbers of indicators that could be used to adequately characterize the contaminant situation, as well as enable a prioritization of problem sediments.
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From page 430... ...
Assessment of benthic infaunal assemblages was performed because of their sensitivity to sediment contamination, their importance in local trophic relationships, and their site-specific response gradients relative to sediment contamination. English sole liver was selected for pathological analyses because it is the organ most closely associated with regulation and storage of many toxic chemicals and has been shown to be afflicted with pathological disorders in sole living in contaminated areas of Puget Sound.
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From page 431... ...
The original data were used to identify statistically detectable increases in sediment contamination, sediment toxicity, or biological effects indicators, and to determine quantitative relationships among these variables. The indices are used to reduce large, complex data sets into interpretable numbers that reflect the magnitudes of the different indicators among study areas.
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From page 432... ...
ph U1() pph 93% 13.0% 6.7% U38 ppb IJSS ppb I < 54 ppb 74 ppb < 36 ppb < 1.8 ppb NOTE: aBoxed numbers represent elevations of chemical concentrations that exceed all Puget Sound reference area values, and statistically significant toxicity and biological effects at the P < 0.05 significance level compared with reference conditions.
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From page 433... ...
are not bioaccumulated because of rapid metabolism in fishes. Overall, the matrix demonstrated that Hylebos Waterway had the largest number of significant indicators (significant EAR for 18 chemicals or chemical groups and eight toxicity or biological effects indicators)
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From page 434... ...
It was assumed that an area or segment requires no action unless at least one of the indicators of contamination, toxicity, or biological effects was significantly elevated above reference conditions. In this approach, problem areas are defined according to two basic criteria: (1)
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From page 435... ...
. Significant indices are defined as follows: Sediment chemistry = chemical concentration at study site exceeds highest value observed at any Puget Sound reference area.
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From page 436... ...
1 significant depression 1 2 significant depressions 2 2 3 significant depressions 3 2 1 taxon with >95% depression 4 Bioaccumulation (fish No significant chemicals O muscle) Significant chemical 1 2 significant chemicals 2 2 3 significant chemicals 3 Significant bioaccumulation of 2 1 chemical posing a human health threats 4 Fish Pathology (liver lesions Maximum Possible Score No significant lesion types 1 significant lesion type 2 significant lesion types 2 3 significant lesion types > 5% prevalence of hepatic neoplasms 4 o 1 2 3 24 .
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From page 437... ...
IDENTIFICATION AND RANKING OF PROBLEM CHEMICALS HIGHEST PRIORITY PROBLEM AREAS SECOND HIGHEST PRIORITY AREAS ~ POTENTIAL PROBLEM AREAS `~ (NO CONFIRMING BIOLOGICAL '`` DATA AVAILABLE) POTENTIAL PROBLEM AREA BY HISTORICAL DATA ONLY N The Commencement Bay investigations indicated that area sediments were contaminated by numerous inorganic and organic chemicals at levels substantially above Puget Sound reference conditions.
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From page 438... ...
Of all detected chemicals, chemicals of concern are defined as chemicals with concentrations exceeding all Puget Sound reference conditions. These chemicals are not necessarily considered problem chemicals, because sediments may be contaminated above reference conditions without exhibiting toxicity or biological effects.
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From page 439... ...
For this complex case of sediment contamination, it enabled regulatory agencies to focus source control and sediment cleanup activities on those sediments and contaminants posing the greatest environmental and public health hazards. This approach is recommended for other areas with contaminated sediments requiring similar assessments and prioritizations before initiating cleanup activities.
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