Regional industries have contributed significant amounts of oil, metals, and other industrial wastes such as sulfur dioxide, hydrogen sulfide, and benzene to the Mississippi River. Imperiled waters abound in Missouri and metals such as lead, zinc, and cadmium were historically released into streams from mines in multiple counties, particularly in the old lead mining belts. Over 1,321 miles of Tennessee rivers and streams, 1,507 miles in Kentucky, and 1,493 miles in Arkansas were impaired in 2012 due to release of metals, pesticides, and PCBs. Many chemicals, such as PCBs, have been banned for decades but persist in suspended and bottom sediments of aquatic environments. Poorly treated sewage and wastewater is also a concern because [...]
