The two stormwater pipes that caused the early February release of as much as 39,000 tons of coal ash into the Dan River in North Carolina have been plugged.
But while damage to the downstream environment is still being assessed, the event appears certain to have far-reaching effects for the utility that owns the site and the state agency that regulates it.
In the weeks since the leak was first discovered on Feb. 2 at a former Eden, N.C., coal-fired powerplant owned by Charlotte-based Duke Energy, the U.S. Attorney's Office in Raleigh has launched an investigation to determine whether the utility's relationship with the North Carolina Dept. of Environment and Natural Resources compromised enforcement of federal environmental protection standards.
Additionally, state environmental regulators say they plan to re-open Duke's existing wastewater discharge permit and will consider requiring the utility to move coal ash from the basins at the Dan River powerplants to a lined landfill.
Duke Energy owns 14 decades-old coal-ash facilities across North Carolina, with a total of 32 storage lagoons. Citing excessive groundwater contamination from two of the facilities, environmental groups filed multiple lawsuits in 2013.
Asserting its pollution enforcement authority, the department intervened in each case. While the agency agreed there were violations, a settlement with Duke Energy resulted in fines for the utility but no requirement to address past pollution or implement preventive measures.
The original settlement may have piqued federal prosecutors' attention, but the coal-ash spill spurred a flurry of subpoenas on Feb. 18 and 19, with nearly 20 current and former agency employees called to testify before a grand jury.
The department also is required to hand over documents and personnel records relating to inspections of coal-ash facilities and potential gifts from Duke Energy to agency employees.
Neither John Skvarla, state secretary of environment and natural resources, nor Gov. Pat McCrory (R), who worked for Duke Energy for 28 years before entering politics, have been subpoenaed.
In a recent interview with the Raleigh News & Observer, McCrory called for placing coal ash in lined facilities and relocating, wherever feasible, existing storage lagoons farther away from rivers.