The much-maligned state agency said it was issuing a notice of regulatory requirement Tuesday, which gives the company until July 9 to "control and prevent further migration of" coal ash pollution. Failure to do so would result in an unspecified fine.
After much public and political pressure, the state fined Duke $25.1 million in March, North Carolina's largest ever penalty for environmental pollution, for violations of state groundwater standards. Duke is contesting that fine in court.
It follows $102 million in fines and restitution ordered by a federal judge last month after the company pleaded guilty to nine violations of the federal Clean Water Act.
DENR said Tuesday that testing found high levels of boron, a metal associated with coal ash impoundments, in drinking water wells outside of the Wilmington plant's boundaries, including three wells a half-mile from the boundary.
"The levels of boron in these wells are a clear indication that coal ash constituents from Duke Energy's coal ash impoundments have infiltrated the groundwater supply," said DENR Assistant Secretary Tom Reeder in a statement. "We are ordering Duke Energy to immediately take corrective actions to prevent further migration of coal ash contaminants."
Boron is generally considered to be non-toxic to mammals, although it is a component in insecticides.
In April, the state acknowledged that the majority of tests in wells near the company's coal ash ponds across North Carolina exceeded state drinking water standards. The company is required to dispose of an estimated 100 million tons of the toxic byproduct in the next 15 years.
Last week, DENR approved one key component of their disposal plans in issuing permits for coal ash dumps in abandoned brick mines in Chatham and Lee counties. Both plans have been hotly contested by locals and environmental groups and also come with myriad concerns about legal liability, although Duke and DENR have argued that they believe the proposal to be safe.
Nevertheless, this week, a handful of environmental groups—the Blue Ridge Environmental Defense League, Chatham Citizens Against Coal Ash Dump and EnvironmentaLEE—criticized DENR. The groups argued that the agency's permits were premature, particularly because, earlier this month, DENR cited Duke contractor Green Meadow LLC for failing to get the proper permits before beginning land clearing on the Lee County site.
"It is clear that despite federal investigations and well-deserved negative publicity, that DENR decisions are still being made in the best interest of Duke Energy, not the people of North Carolina," said BREDL organizer Therese Vick.