Coal combustion residuals, commonly known as coal ash, are created when coal is burned by power plants to produce electricity. Coal ash is one of the largest types of industrial waste generated in the United States. In 2012, 470 coal-fired electric utilities generated about 110 million tons of coal ash.

EPA supports the environmentally sound recycling of coal ash and has developed regulations on the safe disposal of coal ash in landfills and surface impoundments.