The abandoned Cherokee Clay and Brick Mine in Lee County, N.C., may become a landfill for coal ash. Dave DeWitt/WUNC hide caption

itoggle caption Dave DeWitt/WUNC

The EPA is proposing rules that would govern carbon dioxide gas emissions by U.S. power plants. Here, coal is transported via conveyor belt to the coal-fired Jim Bridger Power Plant outside Point of the Rocks, Wyo., in March. Jim Urquhart/Reuters /Landov hide caption

itoggle caption Jim Urquhart/Reuters /Landov

Stanford University's trustees says the school will rid itself of any investments it has made in coal-producing companies. A 2013 file photo shows coal being loaded onto a truck at a mine near Decker, Montana. Matthew Brown/AP hide caption

itoggle caption Matthew Brown/AP

The Freedom Industries facility sits on the banks of the Elk River last Friday, in Charleston, W.Va., site of a chemical spill that has led to a ban on using tap water in the area. The CDC says pregnant women in affected areas should drink only bottled water. Tom Hindman/Getty Images hide caption

itoggle caption Tom Hindman/Getty Images