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Because of its presence in antifouling coatings, stormwater, and industrial and municipal discharges, copper is a ubiquitous contaminant in estuarine and coastal environments. We integrated a system-wide field program with a one-dimensional model to evaluate the overall mass balance of copper in a representative coastal harbor, San Diego Bay, California. Field results from four surveys over 1 yr showed remarkably similar distributions of total copper, with a general increase from the ocean into the Bay followed by a slight decrease in the inner Bay. Total copper concentrations ranged from 5 nmol L Ϫ1 to nearly 60 nmol L Ϫ1. Highest levels for both total and dissolved copper were observed during the winter. Results from a one-dimensional model accounting for the balance of sources, flushing, and losses to the sediment illustrated the importance of accounting for losses of copper to the sediment, without which water column concentrations are overestimated by as much as a factor of five. The time scale for the loss term is on the order of 8-10 d. The model reproduced the field measurements quite well with a loss term controlled by partitioning and settling parameters. The overall balance of total copper in the Bay appears to be split between losses to the ocean via tidal flushing and losses to the sediments via settling. Settling plays an important role in the fate of copper in the Bay, and the sediments are a key endpoint for copper.

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Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. Given the economic, logistical, technological and ecological limitations of contaminated sediment removal and treatment technologies, it is inevitable that some contaminated sediments will be left in place, in the short or the long term, even if contaminants pose some ecological or human health risk. However, leaving sediments in place has met with regulator and public resistance at many sites due to concerns about the long-term risk to the marine environment. It is assumed that the management process will seek to balance two parallel goals: 1) minimizing contaminant risk to the environment and human health and 2) minimizing cost (NRC, 1997). A set of diagnostic tools for characterizing and quantifying potential in-place contaminant pathways will allow for the selection, permitting and monitoring of in situ management strategies. REPORT DATE APR 20062 Same as Report (SAR)18 List of Figures List of TablesAn appropriate evaluation of management choices involves a comparative evaluation of the potential effectiveness of removal-based management strategies vs. appropriate in-place management strategies. This requires knowledge of the relative importance and magnitude of potential pathways of contaminant removal or transport in sediments and the surrounding environment. Determining the relative importance of these mechanisms on a site-specific basis is critically important to the selection, approval and success of any in situ management strategy. Adequate approaches for evaluating these pathways do not currently exist. Assessment and monitoring strategies for multiple contaminant pathways before, during and after in-place remediation must be standardized and validated.While EPA and the Army Corps of Engineers have developed extensive data and guidance documents on the evaluation of contaminant pathways in sediment management (see http://www.wes.army.mil/el/dots/ for extensive resources), the focus and driver have been the disposal of dredged materials (Lunz, et al., 1984;Sumeri et al., 1991;Fredette et al., 1992; Murray et al., 1994; Palermo et al., 1998, USEPA, 1992. By necessity, dredged material will be removed (and exposed at least in part to the water column) and thus pathways of contaminant...

Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.

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