DUK Duke Energy Corp New

By Kris Maher and Erin Ailworth 

River flooding caused the shutdown Friday of a natural-gas plant near Wilmington, N.C. after several breaches in a cooling lake were discovered and some waste tied to the facility's past as a coal-fired plant entered waterways.

Duke Energy Corp. said Friday that the rising Cape Fear River overtopped the dam at a cooling pond next to a coal-ash landfill at its L.V. Sutton Power Plant. The plant burns natural gas after coal-fired units were retired in 2013.

The company believes the coal ash -- which was about 5 feet below a steel wall at last check -- is still contained, but Duke Energy spokeswoman Paige Sheehan said she couldn't rule out the possibility that coal ash was moving into the Cape Fear River.

Michael Regan, secretary of the North Carolina Department of Environmental Quality, said at a press conference Friday that it was unclear whether any coal ash had filtered into the river.

Friday's breaches came in the aftermath of Hurricane Florence, which hit North Carolina a week ago bringing record rainfall over days. Rivers are continuing to rise, and many parts of North Carolina remain under water.

At the site there are two coal-ash storage basins. Ms. Sheehan said floodwaters have submerged the 1971 coal-ash basin that sits next to Sutton Lake -- a 1,100 acre cooling pond built to support coal plant operations. The basin is separated from the cooling pond by a steel wall that has also been submerged.

The company said water was flowing out of the south end of the lake in a second breach, and that cenospheres, hollow beads made of alumina and silica that are a byproduct of burning coal to create electricity, are leaking into the Cape Fear River.

Cape Fear Riverkeeper Kemp Burdette said he was working to launch a boat to assess the situation on Friday, and called any seepage of coal ash into the river a serious concern.

"People should stay out of contact with the water," Mr. Burdette said.

"Cenospheres are coal ash, so if cenospheres are moving into the Cape Fear River, then that means coal ash is moving into the Cape Fear River, " he said. If that happens, then floodwaters could be carrying metals like arsenic, boron and chromium, he said.

The Sutton power plant has been a growing concern amid the record flooding, as some coal ash has already leaked from the site. On Sunday, the company said some coal ash washed into Sutton Lake when part of the top of an earthen landfill was swept away by floodwaters. At the time, the company said it didn't believe any coal ash had escaped into the Cape Fear River.

--Jon Kamp contributed to this article.

Write to Kris Maher at kris.maher@wsj.com and Erin Ailworth at Erin.Ailworth@wsj.com

(END) Dow Jones Newswires

September 21, 2018 14:52 ET (18:52 GMT)

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