Updated 4:53 p.m.
Duke Energy filed appeals Friday of state environmental regulators' April orders to remove coal ash at six North Carolina plants that don't already have approved cleanup plans.
Duke says the state Department of Environmental Quality ignored science and engineering and picked the most expensive and time-consuming option for closing nine coal-ash basins at the six plants. So it is asking the state Office of Administrative Hearings to overturn the orders.
Regulators ordered Duke to excavate coal ash and move it to new lined landfills, to ensure that toxic elements in the ash would not seep into groundwater. Duke is doing that at eight other plants around the state, as required by state law or court orders. But at the rest, the company wants to leave ash where it is, under new waterproof covers.
"The science and engineering tells us it's safe. The federal government says it's safe to cap ash basins, and utilities across the nation are doing it at hundreds of ash basins," Duke spokeswoman Paige Sheehan said Friday. "We think that's the right approach to protect people, protect the environment, and manage cost."
[Related content: NC Orders Duke To Dig Up Coal Ash At All Remaining Sites]
Sheehan said the DEQ's orders would cost $4 billion to $5 billion more than capping the ash in place - or nearly double the company's estimate cost for cleanups in the Carolinas.
And Sheehan said excavation would be the most disruptive - taking more than three decades at the largest sites, like the Marshall Steam Station on Lake Norman, where 34 million tons of ash is stored. Duke also said removal would keep it from meeting cleanup deadlines in the state's Coal Ash Management law.
Besides Marshall, Duke's appeals affect the Allen Plant on Lake Wylie and plants in Cleveland, Person, and Forsyth counties.
If the appeal is not successful, Duke estimates the total cost of coal ash cleanups in the Carolinas could top $10 billion. The company plans to continue asking another state regulator, the North Carolina Utilities Commission, for permission to charge customers for the cleanups. Duke argues that coal ash basin closures are one of the long-term costs of electricity.
The utilities commission has allowed Duke to recover about $175 million annually in cleanup costs so far. The company hasn't said how the added costs might affect customers' monthly bills.
DEQ Secretary Michael Regan responded to Duke's filing with a statement Friday afternoon:
"DEQ continues to stand by its scientific determination that the best way to protect public health, communities and the environment is to excavate coal ash impoundments across the state. We expect DEQ's decision will be upheld."
Meanwhile, Duke has until Aug. 1 to submit final cleanup plans under the DEQ's order. The DEQ will review those and hold additional public meetings. Regan told WFAE earlier this month that final approval could come by the end of this year.
Duke Energy web page on coal ash cleanups, at Duke-Energy.com