Sediments contaminated with toxic chemicals such as PCBs, PAHs, metals, and metalloids can be found in marine and estuarine bays, harbors, lakes, wetlands, and rivers. Aquatic sediments are often the ultimate receptors of contaminants in effluent from military activities on installations. Hundreds of Department of Defense sites already have been identified. And, as estuarine and coastal areas fall under increasing scrutiny, the number of sites requiring action is expected to increase. SERDP and ESTCP research is providing cost savings over current dredging practices, while also reducing the risks to human health and the environment.

Sound science and effective tools that are accepted by the regulatory community are needed to characterize, remediate, manage, and monitor these sites in a manner that reduces risks. SERDP and ESTCP investments in this area are guided by the results of two workshops convened to examine the state of the science and engineering and to identify and prioritize research needs. In August 2004 an Expert Panel Workshop on Research and Development Needs for the In Situ Management of Contaminated Sediments identified 75 specific research needs. A subsequent 2008 workshop, Expert Panel Workshop on Research and Development Needs for Understanding and Assessing the Bioavailability of Contaminants in Soils and Sediments, was held to discuss in greater detail the issue of contaminant bioavailability.

SERDP and ESTCP investments are addressing a wide variety of issues relevant to managing contaminated sediments in place and assessing the processes that govern ecological and human health risks. Work is supported to advance the science and technology of the following:

Fate and Transport – methods to quantify whether contaminants remain in place, are buried over time, or move through the aquatic system and into ecological and human receptors.

Site Characterization and Monitoring – tools to assess the in situ contaminant concentrations and link those to measures of success for in situ remediation and ecosystem recovery.

Bioavailability of Contaminants – tools and methods to support the selection of appropriate cleanup levels.

In Situ Capping – subaqueous caps with sequestering amendments and various design and implementation options.

In Situ Remediation – bioremediation and other methods to sequester contaminants, and techniques to improve understanding of ecosystem risks and recovery from remedial approaches.

Monitored Natural Recovery – assessment tools and methodologies to predict and monitor natural recovery.