The U.S. Environmental Protection Agency (EPA), Wisconsin Department of Natural Resources and Superior Water, Light and Power Co. have awarded a $10.1 million contract to remove contaminated sediment from the C Street Slip in Superior Bay, Wisconsin.

The project is the final phase of a $34 million agreement to remediate contaminated sediment and control pollution sources in the St. Louis River Area of Concern. Work is expected to begin in 2027.

Crews will remove approximately 23,000 cubic yards of contaminated sediment from the 12-acre slip, which contains elevated levels of mercury and polycyclic aromatic hydrocarbons (PAHs). The sediment will be dried and transported to an approved disposal facility. A thin sand cover will then be placed over the remediated area.

Historical industrial activity and wastewater discharges contaminated the St. Louis River’s sediment with mercury, dioxins, polychlorinated biphenyls (PCBs), PAHs and other pollutants.

The cleanup is part of broader restoration efforts funded through the Great Lakes Restoration Initiative and the Great Lakes Legacy Act. Partners have removed more than 1.9 million cubic yards of contaminated sediment and restored more than 1,000 acres of habitat within the St. Louis River Area of Concern.

Completing the C Street Slip project will advance efforts to remove the area from the list of U.S. Areas of Concern designated for significant environmental degradation under the Great Lakes Water Quality Agreement.