The presence of polychlorinated biphenyls (PCBs) in Twelvemile Creek and Lake Hartwell was discovered when the South Carolina Department of Health and Environmental Control (SCDHEC) sampled surface water, sediment, and fish from Twelvemile Creek and Lake Hartwell in the mid-1970s. Results from these analyses indicated PCB contamination, and it was concluded that the source of this contamination was the Sangamo-Weston, Inc. plant in Pickens, South Carolina.
The (file size 7.6M - Adobe PDF file format) Restoration and Compensation Determination Plan (RCDP) documents the injuries sustained by natural resources as a result of the release of PCBs from the Sangamo-Weston plant, and restoration actions that will compensate the public for losses resulting from these injuries.
SCDHEC and the United States Environmental Protection Agency (EPA) issued an advisory against eating fish from Lake Hartwell in 1976; the advisory has been modified periodically on the basis of fish and sediment sampling conducted by SCDHEC. The State of Georgia has also issued lake-wide advisories during this period. As a result of this and subsequent sampling, the Sangamo-Weston, Inc./Twelvemile Creek/Lake Hartwell site was placed on the National Priorities List (NPL) in February 1990.