Dredging continues in St. Louis River AOC May 10, 2021, by Eldin Ganic U.S. EPA will this week begin dredging contaminated sediment in the St. Louis River Area of Concern at Howards Bay in Superior, Wisconsin. St. Louis River AOC is one of the 43 AOCs identified by the United States and Canada in the mid-1980s as the most environmentally degraded areas in the Great Lakes ecosystem. Sediment in Howards Bay is polluted with contaminants typically associated with fossil fuels such as coal, gasoline and oil. The cleanup extends from Hughitt Slip to the head of Howards Bay near 5th and Main Street.