RALEIGH, N.C. (AP) — North Carolina regulators are proposing that about two-thirds of Duke Energy's 32 coal ash basins be fully excavated but say further data is being analyzed for a determination on several others.
A draft report released Thursday classified 12 pits at four plants as an intermediate risk, meaning they must be excavated by the end of 2024. Eight coal ash pits at four sites had already been rated as high-risk under a state law, meaning they must be dug up by the end of 2019.
Duke Energy previously announced that it planned to excavate the residue of coal burned for electricity from 20 basins, but the company's list differs slightly from the state's.
The state says the classifications are subject to a public comment period and aren't final.
Conservationists decried Thursday's announcement, saying an earlier draft of the classifications identified 27 of the basins as high-risk. The Southern Environmental Law Center, which is involved in lawsuits seeking tougher enforcement of environmental laws, obtained the November draft as part of its litigation.
Frank Holleman, a senior attorney at the center, said the revision indicates that leaders of North Carolina's Department of Environmental Quality had political reasons for changing classifications developed by the department's staff.
"This is simply an example of politics trumping science and common sense," he said in a phone interview. "They've either watered down the staff rating, or disregarded them or said they can't make up their mind."
However, the head of the state department, Secretary Donald van der Vaart, said Thursday's report reflected more complete and up-to-date environmental science.
"I am disappointed that special-interest groups attempted to corrupt the process by leaking an early draft that was based on incomplete data," van der Vaart said in a news release.
The classifications were required under a 2014 state law requiring Duke Energy to stop pollution from coal ash dumps by 2029. The state began pursuing stronger regulations and enforcement after a 2014 coal ash spill at one of the utility's power plants coated 70 miles of the Dan River in gray sludge. Coal ash can contain toxic chemicals.
The state classified four coal-ash basins as low-risk. The closure methods for those could vary and must be completed by the end of 2029.
The state tentatively designated eight others as low-intermediate, saying it would finalize the ratings for those pits after analyzing data submitted by Duke Energy in late December.
The state noted in its report that excavations could cost billions of dollars, and the costs could be passed onto customers.
Duke Energy said in a news release that it was fully cooperating with the state's evaluation process and was looking forward to hearing the public's comments.
"In the meantime, we're making strong progress in closing basins in ways that protect people and the environment, comply with state and federal coal ash laws, minimize impact to communities, and manage cost," the release said.