The EPA establishes national technology-based regulations, called effluent limitations guidelines and standards, to reduce discharges of pollutants from industries to waters of the U.S. These requirements are incorporated into National Pollutant Discharge Elimination System (NPDES) discharge permits issued by the EPA and states and through the national pretreatment program. The steam electric effluent limitations guidelines and standards apply to steam electric power plants using nuclear or fossil fuels, such as coal, oil and natural gas. There are about 1,200 nuclear- and fossil-fueled steam electric power plants nationwide; approximately 500 of these power plants are coal-fired. In a study completed in 2009, EPA found that the current regulations, which were last updated in 1982, do not adequately address the pollutants being discharged and have not kept pace with changes that have occurred in the electric power industry over the last three decades. The rulemaking may address discharges associated with coal ash waste and flue gas desulfurization (FGD) air pollution controls, as well as other power plant waste streams. Power plant discharges can have major impacts on water quality, including reduced organism abundance and species diversity, contamination of drinking water sources, and contamination of fish. Pollutants of concern include metals (e.g., mercury, arsenic, and selenium), nutrients, and total dissolved solids.