Duke Energy has been ordered to stop the spread of coal ash contamination in the groundwater near its Sutton Plant in northwestern New Hanover County.

Tuesday, the N.C. Department of Environment and Natural Resources (DENR) announced it has issued Duke Energy a notice of regulatory requirement after recent tests showed high levels of boron in monitoring wells that were at or beyond the facility’s compliance boundary. There were high levels also at three water supply wells approximately half a mile from the facility.

“The levels of boron in the water supply wells did not exceed state groundwater standards but were much higher than concentrations found in background wells in the area,” the department’s news release stated. Boron, a metal, is a recognized indicator of coal ash contamination, according to the release.

“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,” DENR assistant secretary Tom Reeder, said in the release. “We are ordering Duke Energy to immediately take corrective actions to prevent further migration of coal ash contaminants.”

Duke officials responded by email Tuesday afternoon, saying that the timing of DENR's notice of regulatory requirement is "curious and confusing, since the company has been following the state's prescribed process to address the situation at Sutton for months."

"For example, groundwater assessment is already underway with results expected later this summer," Duke spokeswoman Paige Sheehan said in the email. The information will be used to craft the most appropriate corrective action plan while we move toward basins closure.

"Closing the Sutton basins will ultimately address groundwater issues," she continued. "We are awaiting the necessary state permits to begin that process."

The utility has until July 9 to control and prevent further migration of coal ash contaminants and submit a plan to monitor for the effectiveness of its actions, the release stated, adding that Duke’s failure to meet the state’s requirements may result in a fine.

The state fined Duke Energy $25.1 million on March 10 for violations of groundwater standards at the Sutton Plant; it is the state’s largest-ever penalty for environmental damages. Duke is appealing the fine.

“The order issued today is consistent with Governor Pat McCrory’s Executive Order 62, which instructs DENR to take appropriate action to halt any violations of the law in order to protect groundwater and drinking water from the impacts of coal ash,” the release stated. “The notice of regulatory requirement complements the $25.1 million fine by ordering Duke Energy to stop the further spread of any groundwater contamination. DENR’s groundwater assessments of all Duke Energy’s coal ash facilities, including Sutton, are ongoing. The agency will take action, as needed, if other problems are detected.”

Sheehan said that the "vast majority" of state tests thus far "show no indication that Duke Energy plant operations have influenced neighbors' well water." She added that the water system that serves New Hanover County's Flemington community, the nearby Sutton Plant and other properties "continues to meet federal and state drinking water standards with a margin of safety, and there is no public health risk to those residents."

Frank Holleman, senior attorney with the Southern Environmental Law Center, said in an email Tuesday that it is past time for DENR and Duke to act.

"We gave DENR and Duke Energy notice of this serious problem two years ago and have been urging them to stop the groundwater contamination ever since. It is too bad that it took two years for something to happen, and the Wilmington community needs this protection of its groundwater supplies as soon as possible," he said.

In its release, DENR also stated that the department has retained the Atlanta-based firm of Kilpatrick Townsend & Stockton LLP to provide legal services related to Duke Energy’s decision to contest the $25.1 million fine.