The country's largest electricity company will pay an $84,000 penalty and work to stop potentially toxic waste from three North Carolina coal-burning power plants from leaking into groundwater and nearby rivers under a deal with state regulators announced Tuesday.
The deal, already signed by a Duke Energy Corp. executive, includes the penalty for nearly two dozen leaky spots detected at coal ash pits at the Rogers, Allen and Marshall power plants before 2015. The agreement acknowledges the leaks from unlined, earthen holding basins at the power plants into the adjoining Catawba and Broad rivers, a violation of pollution laws.
Coal ash is the residue left after decades of burning coal to generate power. It can contain toxic materials like arsenic and chromium.
The agreement with the state Department of Environmental Quality is significant because the company acknowledges the pollution and accepts its obligation to stop it, said D.J. Gerken, an attorney for the Southern Environmental Law Center, a frequent adversary of Duke Energy.
"In terms of a Duke vice president signing on the line and acknowledging that this is happening, and acknowledging that the company has an obligation to stop the pollution, this is a first," Gerken said.
The company has previously acknowledged that liquids leaking from its basins have infiltrated underground water tables, Duke Energy spokeswoman Paige Sheehan said. But the tainted groundwater flows toward nearby rivers and away from private water wells at homes near the power plants, the Charlotte-based company has said.
"There is groundwater impact, but the groundwater is moving away from neighbors and away from private wells," she said.
But concern about polluted groundwater prompted Duke Energy to provide hundreds of homes using wells within a half-mile of its coal plants with bottled water as a precaution. The company's requested rate increase asks regulators to recoup that cost of providing bottled water for more than two years by charging power consumers.
A 2016 state law requires Duke Energy to install public water lines or water filtration systems to neighboring homes by October. A separate state law passed after a 2014 coal ash spill into the Dan River ordered Duke Energy to close all its ash ponds at 14 North Carolina power plants.
In March 2016, North Carolina environmental regulators issued violation notices for 12 of the company's 14 current or former coal-burning power plants because tainted water from the pits had polluted nearby waterways.
Similar deals are in the works for leaking basins at the eight power plant sites not yet addressed, state environmental agency spokesman Jamie Kritzer said.
Tuesday's agreement, which must still go through a state approval process, calls for Duke Energy to draw water off the surface of the open air basins at the three plants by 2019 in hopes of reducing or eliminating the leaks.
Areas where water seeps through the earthen dams and is collected in a designed system will be regulated under a state-issued permit, if they are not already, the deal said.
The Allen coal plant's coal-fired generators are scheduled to be phased out over the next decade, but there are no plans to retire the Marshall and Rogers plants, Sheehan said. Coal residues will be transported and stored in dry condition, eliminating the former use of storage basins, she said.