The Environmental Protection Agency (EPA) announced plans Tuesday to regulate the management and disposal of coal ash, a byproduct of coal-fired powered plants that poses a threat to drinking water if it leaches into the freshwater supply.

The rules will require ground water monitoring and the installment of liners at new landfills where coal ash is disposed of in solid form. Coal ash is also frequently stored in liquid form in surface impoundments. Under the proposed regulations, there will be stronger oversight of the structural integrity of the impoundments. In 2008, weaknesses in an impoundment in Kingston, Tenn., contributed to a spill that battered millions of cubic yards of land and river with liquid coal ash.

“EPA supports the legitimate beneficial use of coal combustion residuals,” said Mathy Stanislaus, assistant administrator for EPA's Office of Solid Waste and Emergency Response, in a statement. “Environmentally sound beneficial uses of ash conserve resources, reduce greenhouse gas emissions, lessen the need for waste disposal units, and provide significant domestic economic benefits. This proposal will clearly differentiate these uses from coal ash disposal and assure that safe beneficial uses are not restricted and in fact are encouraged.”