ONONDAGA LAKE SEDIMENT REMEDIATION - DREDGING AND CAPPING ALTERNATIVES

摘要

Onondaga Lake is a 12.14 square kilometer (4.6 square mile or 3,000 acre) lake located just northwest of the city of Syracuse in central New York State. The lake has been identified as a federal Superfund site, with the New York State Department of Environmental Conservation (NYSDEC) acting as lead agency overseeing RI/FS activities at the site The contaminants potentially of interest at the site vary by location in the lake, but include mercury, benzene toluene, ethylbenzene, and xylene (BTEX compounds), chlorinated benzenes, polycylic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs). A Feasibility Study for the site and a proposed cleanup plan developed by NYSDEC were completed in November 2004. The site was divided into eight Sediment Management Units (SMUs), based on both physical and chemical characteristics, and remedial alternatives for each of the SMUs as well as combined lake-wide alternatives were developed in the FS. The lake-wide remedial alternatives under consideration include combinations of environmental dredging and in-situ subaqueous capping as remedy components. Several of the alternatives also call for extensive habitat enhancements for the lake. The final selection of a remedy is pending, but will potentially involve one of the largest combined environmental dredging and capping sediment projects in the country. This paper describes the site conditions, remedial alternatives, and the technical basis for the dredging and capping remedy components developed for the FS.