Biological Services Department
ST. MARY’S RIVER AREA OF CONCERN
An “Area of Concern” (AOC) refers to an area that had experienced environmental degradation. There are 27 AOCs in the Great Lakes basin. The St. Mary's River was designated an AOC under the 1987 Great Lakes Water Quality Agreement. Industrial and municipal discharges as well as combined sewer overflows caused impairments of water quality, sediment and biota at the AOC. Priorities for the AOC include restoration of tributaries, cleanup of the Cannelton Tannery Superfund site, sea lamprey control, elimination of combined sewer overflows and remediation of contaminated sediments.