The N.C. Division of Energy, Mineral and Land Resources issued Duke Energy eight notices of deficiency Monday for leaks in the spillways and riser pipes at Marshall Steam Station in Catawba County, Riverbend and Allen Steam Stations in Gaston County, Buck Steam Station in Rowan County, and Cliffside Steam Station in Rutherford and Cleveland counties. All of the plants are in the Charlotte metro area and western North Carolina.
By law, the state can pursue enforcement actions, including fines up to $500 per day per violation, if Duke Energy does not submit schedules for repairing the pipes by July 17. The state sent Duke Energy the notices of deficiency by certified mail and email Monday.
The leaks were discovered by state dam safety engineers who ordered Duke in March to video the insides of the pipes. The leaks included cracks, dripping areas and gushers of water at or near the concrete joints between pipes or in the corrugated metal portions of some of the other pipes. The pipes where leaks were identified are in the dams around the coal ash impoundments. The leaking components include risers that capture overflow from the coal ash impoundments or the spillway systems of the coal ash impoundment dams that carry treated wastewater from the risers to discharge points at the facilities.
State officials did not identify any imminent public health or safety hazards during their video inspections of the pipes.
“If any of the leaks had been identified as posing an imminent threat to the structural integrity of any of the dams jeopardizing public safety or health, we would have taken action immediately,” said Tracy Davis, director of the N.C. Division of Energy, Mineral, and Land Resources. “In that case, we would have ordered the utility to take immediate steps to repair the pipes and would have one of our staff engineers on site to monitor the repairs and the integrity of the dam.”
The state agency ordered Duke Energy to videotape the insides of all pipes in the dam structures at all coal ash impoundments in the wake of the Feb. 2 coal ash spill at the Dan River facility in Eden. Staff members in the agency’s Mooresville Regional Office spent several weeks reviewing digital videos, which were received from Duke Energy May 6.
Also on Monday, the state also sent Duke Energy three inspection letters calling on the utility to provide an engineer’s assessment of aging pipes where no leaks were detected at the Buck, Riverbend and Marshall power plants. Copies of the notices of deficiency and inspection letters can be found on the N.C. Department of Environment and Natural Resources’ Dan River Spill webpage, http://portal.ncdenr.org/web/guest/dan-river-spill, under the “Dam Safety” heading. Video from the pipe inspections will be made available on the website later.
State engineers are continuing to review video of other pipes in dams at coal ash impoundments, and could issue further notices if conditions warrant.