The North Carolina Department of Environment and Natural Resources (DENR) has fined Duke Energy a record $25 million for the years of ground water contamination around its Sutton power facility in Wilmington.

Duke previously acknowledged the problem in 2013.

The $25 million fine is four times larger than the previous record of $5.7 million fine in an 1986 air quality case. The money from the fine goes to a state fund for public schools.

Duke has 30 days to appeal.

Groundwater problems have been detected at all 14 of Duke’s North Carolina coal facilities, half of which it shut down the last few years. The company is assessing the extent of the contamination.

Duke is required to close its 32 ash ponds at the coal plant sites by 2029, with the ponds at Sutton facing a 2019 deadline.

The Raleigh News & Observer reports that the Asheville power plant in “next on the list in what’s expected to be a string of fines.”

That’s only part of the bad news for Duke this week. The company, which is the largest electric firm in the U.S., also said it will pay nearly $150 milloion to settle shareholder claims that they lost millions when the company fired its CEO hours after its 2012 buyout of Raleigh-based Progress Energy.