The sediment cleanup at the former manufactured gas plant (MGP) site is complete!

The sediment cleanup at the former manufactured gas plant (MGP) is complete! A Great Lakes Legacy Act (GLLA) project in 2010-2011 removed contaminated sediment from the St. Marys River and placed a 9-inch sand cover to contain any residual contamination. The cover was also intended to limit direct exposure by aquatic life and provide clean habitat for plants and organisms. 

The former MGP site was identified as the last remaining area of significant contamination in the St. Marys River Area of Concern on the United States side. The cleanup was part of a bi-national effort to restore the St. Marys River Area of Concern. 

Location

The cleanup of the former manufactured gas plant took place along the south shoreline of ​the St. Marys River. The dredged material was staged at the MCM Marine property to remove and treat before being taken to the disposal site.

The St. Marys River is located near Sault Ste. Marie, Michigan. The St. Marys River is a bi-national Area of Concern, bordering the U. S. and Canada. 

Cleanup Process

Sediment remediated: 26,000 cubic yards
Contaminants: PAHs
Method: Mechanical dredging and sand cover
When: 2010-2011
Partners: U. S. Environmental Protection Agency and Consumers Energy
Cost: $8.5 million
Notes: The dredging took place in two phases. Phase 1 removed 6,500 cubic yards of contaminated sediment from commercial marine slips in May and June of 2010. Phase 2 removed 19,500 cubic yards of contaminated sediment from the river next to the shoreline and in the federal navigation channel. A sand cover was placed over the dredged areas in during both phases. 

Long-term Benefits

• ​Long-term, the risk to human health and aquatic habitat is reduced by minimizing direct and indirect contact with contaminated sediment.

More Information

Documents
St. Marys River fact sheet (PDF, 2p, 256KB) January 2012
St. Marys River fact sheet (PDF, 2p, 331KB) February 2010

Stakeholders
Bi-National Public Advisory Council for the St. Marys River Area of Concern
Consumers Energy
Michigan Department of Environmental Quality
U. S. Environmental Protection Agency