Great Lakes Area of Concern Due to environmental contamination, a portion of the river was designated a
Great Lakes Area of Concern (AOC) under the Great Lakes Water Quality Agreement of 1987. The Maumee covers 8,316 square miles and has the largest drainage area of any Great Lakes river. The Maumee AOC is contained within 775 square miles of the river and includes several creeks. The environmental problems were caused by sediment contamination and agricultural runoff. The runoff caused large amounts of
phosphorus to enter the river, eventually leading to manmade
eutrophication in Lake Erie. which was removed in 2015 due to no additional costs required to treat the water prior to agricultural and industrial use •
Restrictions on fish and wildlife consumption due to
PCBs and
heavy metals in
sediments •
Eutrophication or undesirable algae, which causes persistent water quality problems, such as nuisance
algal blooms, decreased water clarity and decrease of dissolved oxygen in bottom waters •
Degradation of fish and wildlife populations These levels are set based on what would be expected from the amount and quality of suitable physical, chemical and biological habitat present in the AOC. •
Beach closings due to the potential for high bacteria levels caused by
combined sewer overflows •
Fish tumors or other deformities are caused by pollutants such as petroleum products and
PCBs in the sediment and water. •
Degradation of aesthetics Materials and events that might cause this include oil slicks, surface scum, combined sewer overflows, excessive dust or
algal blooms. •
Degradation of benthos, which was first documented in the 1950s and has been attributed to waste deposited old dumps, contaminated industrial sites, disposal of
dredged materials and
combined sewer overflows •
Restriction on dredging activities Contaminants in sediment can get stirred up and reintroduced to the water column during dredging activities, which remove sediment and debris from the bottom of a lake or river. •
Loss of fish and wildlife habitat Restoration actions include removing stream barriers, enhancing shoreline complexity, removing invasive species or restoring
wetlands. ==Islands==