NERL Research Abstract EPA's National Exposure Research Laboratory GPRA Goal 5 - Better Waste Management, Restoration of Contaminated Waste Sites and Emergency Response Significant Research Findings Contaminated Sediment Transport and Fate Modeling Scientific Problem and At many Superfund sites, rivers, reservoirs, and other receiving waters are Policy Issues contaminated with PCBs, metals, and other toxic chemicals. Examples of contaminated waters are the Hudson, Fox, and Housatonic Rivers, Lake Hartwell, and New Bedford Harbor. These contaminants often bioaccumulate in fish, thereby posing potential health risks to humans who consume the fish. Remediation of these sites is extremely expensive. Assessment and prediction of the transport and fate of contaminated sediments in these waters is an essential component of risk assessment and remedial decision making at Superfund sites. Modeling the transport and fate of sediments is often one of the requisite components of predicting bioaccumulation. The goal of this research is to develop a consensus framework for transport, fate and bioaccumulation modeling at Superfund sites. The framework includes modeling protocols for applying the component contaminated sediment transport and bioaccumulation models. This task has the following objectives: 1. Evaluation of existing contaminated sediment mass fate and transport models and bioaccumulation models. 2. Development of new modules for selected fate and transport model(s) for certain types of water bodies to address the identified sediment-related needs of OERR and the Regions. 3. Report on the evaluation of long-term (i.e., 1-10 years) accuracy of the upgraded contaminated sediment fate and transport models by modeling the transport and fate of sediments in Lake Hartwell. 4. Produce a consensus framework for modeling remedial alternatives in large water bodies and estuaries. • The evaluation of contaminated sediment transport and fate models was completed in April 2003. A seminar was presented to OERR in May 2003 on the results of this evaluation. • The evaluation of chemical bioaccumulation models is ongoing. This task will be completed in November 2003. Another seminar will be presented to OERR on the results of this evaluation. • The evaluation of the long-term accuracy of an advanced contaminated sediment transport and fate model is ongoing. The data set to model Lake Hartwell is currently being developed. • Testing of contaminated sediment transport models has been initiated. In addition to Lake Hartwell, the following surface waters are going to be modeled: Housatonic River, MA; Lower Duwamish Waterway, WA; and Charleston Harbor, SC. Research Approach Results and Implications ------- The planned collaboration with NHEERL in the development of the consensus framework has been canceled due to NHEERL's contaminated sediment funding cut. Imhoff, J.C., A. Stoddard, and E.M. Buchak. 2003. Evaluation of Contaminated Sediment Fate and Transport Models. Final Report, U.S. EPA, National Exposure Research Laboratory, Athens, GA, 141 pp. Future Research A NRC Post-Doc will start December 2003 to work on the development of new modules for selected fate and transport models for certain types of water bodies. Research Collaboration and Publications Contacts for Additional Information Earl Hayter, Ph.D. Questions and inquiries can be directed to: National Exposure Research Laboratory Ecosystems Research Division 960 College Station Road Athens, GA 30605 Phone: 706/355-8303 email: havter.earl@,epa.gov ------- |