St. Louis River Alliance

About the AOC

The St. Louis River

The St Louis River, the largest U.S. tributary to Lake Superior, has a watershed of 3,634 square miles, entering the southwestern corner of the lake between Duluth, Minnesota and Superior, Wisconsin. The river flows 179 miles through three distinct areas: coarse soils, glacial till and outwash deposits at its headwaters; a deep, narrow gorge at Jay Cooke State Park; and red clay deposits in its lower reaches. As it approaches Duluth and Superior, it becomes a 12,000-acre freshwater estuary. The upper estuary has wilderness-like areas, while the lower estuary is characterized by urban development, an industrial harbor and a major port. The lower estuary includes St. Louis Bay, Superior Bay, Allouez Bay and the lower Nemadji River.


The St. Louis River was designated as one of the 43 Areas of Concern (AOC) on the Great Lakes due to significant issues with pollution and degraded habitat. AOCs are places that were polluted by common practices of dumping untreated waste on land and water. These problems are being addressed by the St. Louis River System Remedial Action Plan (RAP), which focuses primarily on the last 39 miles of the St. Louis River from below Cloquet, Minnesota to its mouth on Lake Superior.

The RAP began in 1989 as a collaborative effort between the Minnesota Pollution Control Agency and the Wisconsin Department of Natural Resources. Nine issues (Beneficial Use Impairments, or BUIs) were identified that need to be addressed before the St. Louis River can be “delisted” as an Area of Concern.

“St. Louis River Area of Concern”: SEDIMENT CLEANUP PROGRESS

In 2016 and 2017, the SLRA lead the effort to secure $25.4 million dollars in bonding money from Minnesota in order to clean up contaminated sediments in the harbor.  This triggered an additional $47.2 million from EPA to complete the projects.  Hundreds of SLRA members and Coalition supporters joined together to make this effort a reality.  You can now see the work in progress around the harbor.  We would like to thank you all for your support!

Check out the MPCA site for updates and all the details. 

CLICK HERE to see how your contribution directly contributed to the ongoing progress in the harbor.

Area of Concern 101 by Wisconsin DNR (video)    Harbors and waterways are being cleaned up around the nation. Learn how an Area Of Concern transforms and get involved locally by clicking here:

Original AOC Documents

Local, state, tribal, and federal agencies are working in partnership to clean up and restore the St. Louis River, and move it from an “Area of Concern” to an “Area of Recovery”. The St. Louis River Alliance connects citizens to this process as well as work together to protect, restore and enhance the St. Louis River.

Key Partner Agencies in the AOC Process:

Wisconsin Department of Natural Resources
Minnesota Pollution Control Agency
Fond du Lac Tribe of Lake Superior Chippewa
Minnesota Department of Natural Resources