MPCA advances cleanup of St. Louis River Area of Concern with Scanlon reservoir

Contact: Lucie Amundsen, 218-302-6600

The Minnesota Pollution Control Agency (MPCA) today released its environmental assessment of a project to remove decades-old legacy pollution from the Scanlon Reservoir in the St. Louis River Area of Concern (SLRAOC). The Scanlon Reservoir sediment remediation will check another box as Minnesota Pollution Control Agency and U.S. Environmental Protection Agency (EPA) progress in the SLRAOC. Short-term impacts include a temporary closure of the Scanlon River Park access off Hwy. 61 from November 2021 through November 2022 to facilitate project construction.

The Scanlon reservoir site is located just upstream of the Scanlon Hydroelectric Station. The sediment is contaminated with dioxins/furans from historical industrial discharges in the reservoir prior to modern environmental regulations. The cleanup project involves applying an activated carbon amendment in approximately 14 acres of the 43-acre reservoir to remediate the contamination.

Applying varying forms of activated carbon will help absorb toxins in the reservoir’s surface sediments — where macroinvertebrates live and feed — and reduce the levels of dioxins/furans that are passed up the food chain. The open water areas in the area being treated will receive a granular activated carbon amendment mixed with a thin layer of sand. Shallower areas will receive a pelletized activated carbon amendment form, without sand, to protect sensitive vegetation and wetland habitat.

Next steps include signing a Great Lakes Legacy Act project agreement with the U.S. EPA, expected next month. Remedial construction would start in the fall of 2021. The project will cost an estimated $6 million. Under the project agreement, MPCA will contribute up to $2.1 million of the cost. The EPA, via a Great Lakes Legacy Act cost-sharing partnership, will fund the balance.

The MPCA is inviting the public to review its environmental assessment worksheet (EAW) and provide comments. The EAW describes the project’s potential effects on the environment, including its impact on nearby land uses, geography, habitat, and historic sites. The EAW also details air and vehicle emissions, dust, traffic, and odors that the project might produce and describes the potential for temporary indirect impacts to sensitive ecological areas from operational noise and increased turbidity.

You can review the EAW on the MPCA website. Request a copy from or submit comments to Patrice Jensen (651-757-2465), MPCA, 520 Lafayette Road North, St. Paul, MN 55155-4194 by 4:30 p.m. on Thursday, June 24, 2021.

The SLRAOC has prioritized 43 construction projects to address contaminated sediment and restoration of aquatic habitat in Minnesota and Wisconsin; 16 of these projects are being led by the MPCA. The U.S. and Canada designated 43 such areas of concern where historic industrial activities left a legacy of environmental damage. In 2013, the MPCA, Minnesota and Wisconsin Departments of Natural Resources, and the Fond du Lac Band of Lake Superior Chippewa developed a comprehensive plan to address these legacy damages in the SLRAOC. As of October 2020, these organizations have completed 41 of the 80 management actions that need to be completed before delisting can be proposed.