Cancer-causing industrial chemicals have been found in the sewers at a Columbia-area restaurant as a state investigation of illegal dumping expands from the Upstate to the Midlands, where utility officials scrambled this week to learn more about the threat to central South Carolina.
The concern is whether PCBs flowed from wastewater treatment plants into rivers or if sewer sludge with elevated PCB levels was dumped in landfills or used to fertilize farm fields.
However, drinking water in Beaufort County appears to be safe, according to Beaufort-Jasper Water and Sewer Authority spokesman Matthew Brady.
"We will be following the rule that was released today regarding PCB testing for our sludge. We'll take it very seriously," Brady said Thursday, adding that he expects the authority's inspection will turn up no problems.
Banned more than three decades ago by the federal government, PCBs recently have been found in a string of Upstate wastewater treatment plants that discharge into rivers. The materials are considered probable human carcinogens if people are exposed in sufficient amounts. One source of PCBs is contaminated fish that people eat from rivers, some of which accept treated sewage.
State regulators said Wednesday they have no evidence that any rivers have been contaminated or that drinking water is unsafe, but they are investigating reports that someone, perhaps a sludge hauler, illegally discharged material containing PCBs into manholes and restaurants' grease traps.
Sewer systems, including ones operated by Columbia and the East Richland Public Service District, planned to check sludge and wastewater for signs of PCBs, utility officials there said. East Richland has done some testing, while Columbia -- which operates the state's largest wastewater plant -- planned visual inspections to look for an oily sheen in wastewater that would indicate PCBs.
Officials with the S.C. Department of Health and Environmental Control met earlier this week with utility officials to discuss the potential threat and actions that could be taken.
PCBs can persist for years in the environment, and old, polluted industrial sites can contain the materials. In the Upstate, investigators suspect some of the PCBs found in sewer plants came from an old textile mill that is undergoing a cleanup. In the Columbia area, PCBs also are being cleansed from a site in the Irmo area.
Beaufort Gazette and Island Packet staff writer Rebecca Lurye contributed to this report.