Duke University researchers issued a study Monday warning that tons of ash from coal-burning power plants are polluting North Carolina's drinking water with arsenic, selenium, cadmium and other toxins.
The report is part of the fallout from the December 2008 dam spill in Tennessee that focused public attention on the risks associated with storing coal ash in impoundments and retaining ponds. Environmental groups since then have been urging federal and state agencies to regulate coal ash pits as hazardous waste.
Duke researchers wrote that coal ash residues "represent one of the largest industrial waste streams in the U.S. and are not classified as hazardous waste."
"Our data clearly show high contaminant levels that suggest the need for enhanced removal/wastewater treatment," Duke researchers wrote. "The results of this study have significant implications for hundreds of similar sites across the US given that CCR [coal combustion residue] storage facilities continuously generate contaminants via leaching and transport to nearby hydrological systems."