River, Cottage Grove cleanup will be expensive, complicated

The Star Tribune reported March 31 that cleaning up chemical contamination in the Mississippi River and at the 3M plant in Cottage Grove will include river dredging to remove highly contaminated sediment in a cove and sandbar and will cost $12.5 to $18 million. 3M submitted the plan to Minnesota Pollution Control Agency (MPCA). In addition to MPCA approval, 3M will need a permit from the Minnesota Department of Natural Resources and perhaps from the US Army Corps of Engineers to dredge in the river and to account for damage to wetlands and wildlife.

The pollutants of concern are two perfluorochemicals (PFCs) that 3M manufactured for more than half a century and were widely sold and used in Scotchgard™, Teflon®, firefighting foam and other coatings. The chemicals dont break down or degrade in the environment. Theyve been found to cause liver, developmental and other health problems in laboratory animals. 3M stopped manufacturing them in 2002.

John Linc Stine, director of the environmental health division of the Minnesota Department of Health, said no communities near the Cottage Grove plant draw water from the river for drinking. The MPCA said it will review the proposal over a month and could accept, modify or reject it.

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Cleaning up river site may cost 3M $18 million — Star Tribune, 31 March 2008