The watery home of Duluth’s retired ore carrier William A. Irvin is one step closer to being cleaned up. The MPCA has selected a remedy that caps the Minnesota Slip’s contaminated sediment.
All options considered by the agency and the public were weighed against four goals:
- Minimize exposure to sediment contaminants that contribute to fish-consumption advisories.
- Minimize exposure of aquatic organisms to contaminated sediments.
- Preserve water depth to enable the current use of the slip.
- Enhance deep water aquatic habitat where possible.
The selected remedy, with an estimated $1.6 million cost to complete, met those goals. It was also the least expensive, because it moves 2,500 cubic yards of contaminated sediments to the slip’s deeper areas, covers the leveled sediment with a 3-foot cap, and requires no offsite disposal.
In partnership with the U.S. Environmental Protection Agency and U.S. Army Corps of Engineers–Detroit district, MPCA staff has begun the design process. This effort will include a more extensive environmental review and allow for additional public comment. Funding for the construction portion of the cleanup depends on the Minnesota Legislature passing the bonding bill which contains money for this and other St. Louis River Area of Concern cleanup projects. Barring unforeseen design or funding delays, construction could begin in 2018.
The slip’s contamination is the result of a century of industrial and shipping activities in the Duluth-Superior harbor that left “legacy pollutants.” The site is one of ten identified in Minnesota for cleanup as part of the St. Louis River Area of Concern Remedial Action Plan.
The Minnesota Slip is located within the St. Louis River Area of Concern, one of 43 so-designated Great Lakes basin locations where historic shoreline alterations and industrial contamination caused impairments affecting its ability to support wildlife habitat and aquatic life. Successful completion of the Minnesota Slip remediation project would contribute to a healthier St. Louis River.
For more information, visit the MPCA’s Minnesota Slip cleanup webpage.