Work begins on PCB contaminated sediment in Mich.

March 15 -- Work has begun on what the U.S. Environmental Protection Agency calls a "short-term cleanup" of polychlorinated biphenyl contaminated sediment in the St. Clair Shores, Mich., storm sewer drainage system.

The project includes a 10-mile portion of the system as well as two canals that drain into Lake St. Clair, the EPA said. The drain system is "an enclosed concrete sewer about 10 feet below street level," the agency said.

Work will include removal and disposal of the PCB-contaminated sediment that has collected in the drain since 2006 and removal and disposal of sediment from the adjacent sewer outfall that leads to the canals.

Past work has been done to remove PCBs from the drainage system, but the agency has not determined the source of the contamination.

The site recently was proposed to be included on the Superfund Natural Priorities List, the EPA said.

The EPA, in 2006, installed a synthetic liner designed to prevent PCB seepage around the cement drain pipe. Contaminated soil was also removed from several yards or public easements along the drainage system, the EPA said. Despite this work, the EPA said, the source has not been determined.

Contact Waste & Recycling News senior reporter Jim Johnson at 937-964-1289 or jpjohnson@crain.com