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Workshop Summaries
Pages 20-36

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From page 20...
... There has been only a modest effort expended to date to systematically determine the areal extent of sediment contamination in this country. Recently EPA has begun an effort to develop methodologies to assess the biological impact of in-place sediment contamination.
From page 21...
... involve marine or estuarine waterways." EPA has concluded that "some of the major sites that have been identified that contain chemicals of interest at high concentrations include Puget Sound waterways, Corpus Christi Harbor, New York Harbor, Baltimore Harbor, Boston Harbor, New Bedford Harbor, Black Rock Harbor, the California sewage outfalls at Palos Verdes and parts of San Francisco Bay" (Zarba, page 45~. The NOAA National Status and Trends Program currently provides the most comprehensive and systematic national data set on sediments.
From page 22...
... , and Richard Swartz (pages llS-129~. The speakers discussed the Apparent Effects Threshold method, the Sediment Quality Triad, the Equilibrium Partitioning approach, and the Sediment Bioassay approach.
From page 23...
... Furthermore, the cost of developing criteria can be quite significant. The Equilibrium Partitioning approach uses existing water quality criteria effects data, together with estimated concentration of a specific contaminant in the sediment interstitial water, to determine if the contaminant will be toxic to benthic invertebrates.
From page 24...
... However, concern was expressed about the effect of grain size and the degree of hydrophobicity needed in order for this approach to be valid. The Sediment Bioassay approach can be used in two ways to determine sediment quality values.
From page 25...
... Ultimately, the method used to determine sediment quality criteria should be one that can be conducted routinely and cost-effectively. Significance of Contamination A discussion of effects of sediment contamination on biological communities and human health was based on the papers presented by John Scott (pages 132-154)
From page 26...
... Since there are no standardized sediment bioassays with ecologically relevant species for all areas and types of contaminants present, the COE has used a variety of methods -- including the Equilibrium Partitioning method -- in addition to bioassay testing. The extent of contaminant transfer from the marine environment to humans is also poorly understood and underassessed.
From page 27...
... Resuspension of Sediments Both the NRC Committee on Contaminated Marine Sediments and the Society of Environmental Toxicology and Chemistry workshop on Priority Research Needs on Risk Assessment (August 1987, Breckenridge, Colorado) have targeted sediment resuspension and mobilization as a key research need.
From page 28...
... John Cullinane presented a procedure for selection of remedial alternatives called the Dredged Material Alternative Selection Strategy (DMASS)
From page 29...
... However, the COE has a broader umbrella of evaluation procedures under its Long Term Management Strategy initiative, which includes consideration of other aspects of decision making, such as cost. No other comprehensive strategies for evaluation and selection of remedial alternatives specific to contaminated sediments were identified by the work group.
From page 30...
... Disposal in open water, including ocean disposal, may be a viable option if appropriate control measures, such as capping, are implemented. Except for prohibited substances, disposal in open water with appropriate controls is compatible with regulatory requirements under the Clean Water Act and Ocean Dumping Act and is accepted under the London Dumping Convention.
From page 31...
... Research issues related to capping that need to be addressed include capping procedures for deeper water sites and mass release predictions. These research needs have become evident with the proposed Everett Navy Homeport project and the pending designation of a deep-water site for disposal of material from New York Harbor.
From page 32...
... The COE's New York District has completed a draft environmental impact statement for use of these pits as containment disposal sites for contaminated sediments. The dredged sediment would be placed in the pits and capped with clean sand to both isolate and contain the contaminated material and to restore the seafloor to its original bathymetry and compos ition .
From page 33...
... For cases requiring remediation not listed under Superfund, the question of who bears the costs remains . In general, remedial actions are costly and increasing levels of remediation lead to rapidly increasing costs.
From page 34...
... A site at Ashtabula will involve disposal of 20,000 yd3 at a permitted hazardous waste site, and incineration of 5,000 yd3 of hot spot material. CASE STUDIES Case studies were presented during the symposium for New Bedford Harbor, the Hudson River, the James River, and Commencement Bay.
From page 35...
... The sediments of concern in the Everett Homeport project contain stressed benthic communities with low biomass values, low diversity values, and low Infaunal Trophic Index values. Various remedial actions have been or are being cons idered for the five areas .
From page 36...
... Contaminated sediment disposal options for the Everett Homeport project were nearshore/intertidal disposal, upland disposal in a saturated or unsaturated sediment condition, or conf ined aquatic disposal (capping in deep water)


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