St. Louis River AOC Deal Signed

The U.S. Environmental Protection Agency (EPA) has signed a $4.5 million agreement to remediate contaminated sediment in the St. Louis River Area of Concern (AOC) on Lake Superior.

Photo by Nelson T. French

The St. Louis River AOC is one of 43 toxic hotspots identified by the United States and Canada in the Great Lakes basin, and is the second largest AOC in the United States. EPA and the Minnesota Pollution Control Agency (MPCA) will fund the work through a Great Lakes Legacy Act cost-sharing partnership.

“EPA’s partnership with Minnesota continues to produce results in the St. Louis River AOC,” said EPA Great Lakes National Program Manager and Regional Administrator, Kurt Thiede. “This sediment cleanup will address a century’s worth of contamination, protecting public health and aquatic life while improving access to a port that is critical to the region’s economy.”

The project will remediate approximately 55,000 cubic yards of contaminated sediment in the Azcon/Duluth Seaway Port Authority slip, an active 6.5-acre shipping slip located in the Duluth-Superior Harbor.

The sediment is primarily contaminated with polycyclic aromatic hydrocarbons, or PAHs. Approximately 600 cubic yards of the most contaminated sediment in the Slip will be removed and properly disposed of.

The remainder will be capped in place with clean sediment to prevent exposure to aquatic organisms. The cap will be armored with stone to protect against damage from vessel traffic.

The MPCA has agreed to contribute up to $1,575,000 to the total project cost of $4.5 million.