Updated 11 a.m.
Duke Energy says it will file an appeal soon of state regulators' orders last week that it must excavate coal ash from six coal-fired power plants in North Carolina that don't already have approved closure plans.
The company said in a statement Tuesday that the orders would "impose a financial burden on our customers and the economy of the Carolinas."
Duke said it plans to appeal the orders to the North Carolina Office of Administrative Hearings. The quasi-judicial state agency hears appeals of decisions by state regulators, such as the N.C. Department of Environmental Quality which issued last week's orders.
The orders mean Duke would have to dig up ash at Marshall Steam Station on Lake Norman and the Allen Plant on Lake Wylie in Gaston County, as well as at plants in Cleveland, Person, and Forsyth counties.
Duke noted that NCDEQ had rated the nine coal-ash basins at the six plants as "low risk." The company said digging up coal ash and moving it to new, lined landfills would be "the most expensive and disruptive closure option possible."
Duke argued that NCDEQ's orders “lacked full consideration of the science and engineering” involved.
Duke favors leaving the most of the ash in place with new waterproof covers. But the DEQ rejected that idea, saying it does not protect the environment or public health.
Duke Energy said if it is forced to excavate the ash it would nearly double its cleanup costs to more than $10 billion in the Carolinas.
The company has said it would seek to pass the cost on to customers through a future rate increase. It hasn't said when it might make a rate increase request, but recent regulatory filings hint that it could come by year's end. The N.C. Utilities Commission has allowed Duke to charge customers for previous coal ash cleanup costs, minus a penalty.
Frank Holleman, senior attorney with the Southern Environmental Law Center, criticized Duke's decision to appeal. The center has won legal battles requiring Duke to excavate ash at other plants.
"Duke Energy’s decision to fight these cleanups ignores the science confirming that its sites have been polluting our water for decades and will continue to do so for centuries. And it places the public and our rivers and lakes at continued risk of another coal ash catastrophe from the next hurricane or structural failure."