The Ohio River flows through or borders six States and is 981 miles (1,579 kilometers) long, starting at the confluence of the Allegheny and Monongahela Rivers in Pittsburgh, Pennsylvania, and ending in Cairo, Illinois, where it flows into the Mississippi River. At the confluence, the Ohio River is considerably bigger than the Mississippi River. More than 25 million people, almost 10 percent of the U.S. population, live in the Ohio River Basin, and it is source of drinking water for more than 3 million people even though many sections do not meet water quality standards for bacteria and pathogens, PCBs, lead, mercury, metals, organics, and other pollutants. There are 20 dams on the Ohio River that are managed by the U.S. Army Corps [...]