Quantifying In Situ Metal and Organic Contaminant Mobility in Marine Sediments

摘要

Contaminants enter shallow coastal waters from many sources, including ships, shoreside facilities, municipal outfalls, spills, and nonpoint source runoff. Sediments are typically considered a primary sink for these contaminants. Sediments in many bays, harbors, and coastal waters used by the Department of Defense (DoD) are contaminated with potentially harmful metal and organic compounds. DoD is required by the Comprehensive Environmental Resource Conservation and Liability Act (CERCLA), as amended by the Superfund Amendment and Reauthorization Act (SARA) of 1986, to assess and if necessary remove and remediate these sites and discharges in order to protect the public health or welfare of the environment. To determine whether contaminants are moving into, out of, or remaining immobilized within the sediments, a determination of contaminant flux must be made. This project addresses the DoD/Navy requirement for compliance, cleanup assessment, and remediation decisions using an innovative technology to directly quantify the mobility and bioavailability of contaminants in marine sediments. The environmental risks posed by these contaminants are determined largely by the degree to which they remobilize into the environment. The project included demonstrations of the commercialized Benthic Flux Sampling Device (BFSD2) at sites in San Diego Bay (Paleta Creek) and Pearl Harbor (Middle Loch and Bishop Point). The demonstrations were used by evaluators from the CalEPA as part of their Technology Certification program process. The demonstrations were successful in showing accurate, precise, and repeatable results at both locations. The San Diego sites were used to emphasize repeatable performance, and the Pearl Harbor sites were used to emphasize the range of conditions for operation.