Several gas utilities in the United States, or their predecessors, operated Manufactured Gas Plants (MGPs) in the past. These MGPs, in general, are located near water bodies. Contaminated sediments are now becoming a major issue at most former MGP sites. Current approaches for remediation of contaminated sediments include natural recovery, excavation/dredging, and engineering control (capping, etc.). Natural recovery and capping are not permanent remedies; therefore, these remedial alternatives put limitations on the use of the property. Excavation/dredging is a permanent remedy, however, this remedial alternative is relatively very expensive. Natural resource damage assessment, and therefore the extent of remediation required, will be high if “total concentration” of contaminants is used to guide management of contaminated sediments. Although a few alternative methods/procedures for characterization and management of contaminated sediments are available, no standardized methods are available other than those that are based on total contaminant concentrations. Research is being conducted to determine whether contaminant “bioavailability” tests, originally developed for soils, can be applied to sediments as well. These may serve as the basis for “risk-based” remedial actions for the management of contaminated sediments. The overall objective of this research is to develop the protocols to minimize the quantity of MGP contaminated sediments requiring remediation, thus reducing the remediation costs, while still providing adequate protection to human health and the environment.
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