Which industries are the worst water polluters?

The industry responsible for the worst water pollution is the electric power industry, as reported in a 2013 study by the Political Economy Research Institutue of the University of Massachusetts Amherst. In addition, chemical manufacturers and the Department of Defense are cited as major polluters alongside the electric industry.

Six of the top 10 polluters are primarily concerned with electric power generation and distribution. These six polluters are Ohio Valley Electric, American Electric Power, the United States Tennessee Valley Authority, PPL and Dominion Resources, as well as Southern. Together, these companies account for just under 50 percent of the total surface water pollution reported in the study; pollutants from these industries consist largely of heavy metals such as lead, arsenic and copper.

Three of the remaining four top polluters are involved in chemical manufacturing, with Dow Chemical, Evonik AG and Ferro accounting between them for approximately 17 percent of the surface water pollution reported in the 2013 study. These polluters primarily emit organic compounds into the water.

The Department of Defense is also cited as a major source of water pollution, accounting for 8 percent of total water pollution. The primary pollutant discharged from Department of Defense facilities is nitroglycerin.