Duke Energy’s temporary pumping of two coal ash ponds in Chatham County, which was discovered last week by regulators and environmentalists, illegally put 61 million gallons of wastewater into a tributary of the Cape Fear River.
Regulators on Thursday cited the utility for violating the conditions of its wastewater permit at the closed Cape Fear power plant.
The company had said it was lowering the water level to do routine maintenance on risers, which are vertical spillway pipes. But the state Department of Environment and Natural Resources said Thursday what the company did “far exceeded what would reasonably be considered routine maintenance.”
Workers bypassed the risers by using a pair of temporary pumps, and drew down the water level so rapidly that the system failed to function as a treatment system, inspectors said.
DENR has notified downstream municipalities, which have not reported any problems so far. Based on records at the plant, state regulators determined 61 million gallons of wastewater have been pumped into the tributary periodically since September.