The U.S. EPA and Minnesota Pollution Control Agency have signed a $16 million project agreement to remediate contaminated sediment in the “ponds behind Erie Pier,” two backwater ponds surrounded by shallow marsh wetlands in Duluth, Minnesota.
“EPA’s partnership with Minnesota continues to produce results in the St. Louis River Area of Concern,” said acting EPA Regional Administrator, Cheryl Newton. “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.”
EPA and MPCA will fund the sediment remediation work through a Great Lakes Legacy Act cost-sharing partnership. Under the project agreement, MPCA will contribute up to $5.6 million of the total estimated project cost of $16 million.
The project is slated to begin early summer 2021 with the help of the U.S. Army Corps of Engineers.
“The great progress in the St. Louis River is pushed forward by the partnerships between federal, state, local and tribal governments, as well as many stakeholders,” said MCPA Commissioner, Laura Bishop. “These vital restoration projects continue to bring exciting opportunities that support healthy families, recreation and our economy.”
The project will remediate approximately 45,000 cubic yards of contaminated sediment in the two ponds, located near the Duluth-Superior Harbor in the St. Louis River Area of Concern (AOC).
The sediment is primarily contaminated with PCBs, PAHs, mercury and chromium. The remediation project will consist of dredging all contaminated sediment in the project area, temporarily storing and dewatering the sediments on site, disposing of the dewatered sediments at an off-site landfill, placing approximately 6-inches of clean cover material over the dredged area, and revegetating the remediated site.
The cleanup will reduce toxins in the “benthic” or bottom dwelling community in the ponds, reducing the contaminants in the macroinvertebrates which live in the pond sediment and provide an important food source for fish.
As a result, contaminant levels in fish will be reduced, making them safer to eat, EPA said.