At the annual St. Louis River Summit recently held in Superior, Wisconsin, it was announced that the U.S. Environmental Protection Agency has agreed with the states’ recommendations to remove the Fish Tumors and Other Deformities Beneficial Use Impairment (BUI) identified for the St. Louis River Area of Concern. This accomplishment is another step toward the AOC’s entire delisting, which is targeted for 2025.
The BUI removal comes after years of sampling to learn whether fish tumors and other deformities are more common in the AOC. Research on White Sucker fish in the St. Louis River AOC showed low rates of fish tumors and other deformities. These positive results led the Wisconsin Department of Natural Resources and the Minnesota Pollution Control Agency to recommend removal of this particular impairment and the EPA agreed. Coincidentally, this BUI removal helped EPA meet their Great Lakes Restoration Initiative Action Plan.
Researchers sampled fish in 2011, 2013, and 2015. Evidence confirmed that the tumor incidence rate was not significantly different between the river and Lake Superior. Further, the St. Louis River AOC tumor rates were lower than other sites in the Great Lakes.
Because of these findings, the Fish Tumors and Other Deformities BUI has been removed from the St. Louis River AOC. Documentation of this decision can be found on the Wisconsin Department of Natural Resources website.
The St. Louis River AOC now has seven remaining BUIs to address before the entire St. Louis River AOC can be delisted. It is one of 43 such AOCs designated in 1987 as the most highly contaminated areas in the Great Lakes. This work was included in the St. Louis River AOC Remedial Action Plan and was funded primarily by the federal Great Lakes Restoration Initiative.
The primary partners involved in this work included the Fond du Lac Band of Lake Superior Chippewa, Minnesota Department of Natural Resources, Minnesota Pollution Control Agency, U.S. Environmental Protection Agency, and the Wisconsin Department of Natural Resources.