Open for comment: Proposal to remove the fish impairment from the St Louis River Area of Concern

Contact: Steve Mikkelson, 218-316-3887

Recent research in the St. Louis River estuary shows that white sucker fish have a low rate of fish tumors and deformities. Previous observations led authorities to believe the fish were at risk, and to consider the estuary “impaired.” (A body of water is considered “impaired” if it fails to meet one or more water quality standards.) However, in response to the recent research, the Wisconsin Department of Natural Resources (WDNR) and Minnesota Pollution Control Agency (MPCA) are requesting that the St. Louis River no longer be listed as impaired for fish tumors and deformities.  

Fish sampled in 2011, 2013, and 2015 were studied to determine if fish tumors and deformities were more common in the St. Louis River Area of Concern (AOC) than elsewhere. The St. Louis River AOC is one of 43 such areas designated by the EPA in 1987 as the most highly contaminated in the Great Lakes. The research showed that the occurrence of tumors in white sucker fish was not significantly different between the river and Lake Superior, and lower than in other sites in the Great Lakes. The age and gender of the fish were found to be more important factors for fish tumor development.

Because of these findings, the MPCA and the WDNR proposed that the fish tumors and deformities impairment be removed for the St. Louis River AOC. The removal proposal and study are available on the WDNR website for review. See a fact sheet and comment form at:

Submit comments to Matt Steiger, Wisconsin DNR, AOC Coordinator, 1701 N 4th St, Superior, WI 54880 or at by 5:00 p.m., Oct. 12, 2018.

Paper copies of the draft document are available for review at the Superior Public Library at 1530 Tower Ave., and the Duluth Public Library at 520 W. Superior St. Paper comment sheets are included and pre-formatted for mailing.

A final removal recommendation will be submitted to the U. S. EPA after public input has been reviewed and considered. General questions about the removal proposal can be directed to Matt Steiger at 715-395-6904, or Barb Huberty, MPCA AOC Coordinator, at 218-302-6630 or by email at

The St. Louis River AOC will have seven remaining impairments to address before the entire St Louis River AOC can be delisted. Some species of fish in the river still contain high levels of pollutants such as mercury and polychlorinated biphenyls or PCBs.

This work was included in the St. Louis River AOC Remedial Action Plan and funded primarily by the federal Great Lakes Restoration Initiative. The primary partners involved in this work included the U.S. EPA, WDNR, Minnesota Department of Natural Resources, MPCA, and the Fond du Lac band of Lake Superior Chippewa.