Cape Fear River flooding damages Sutton Lake, causes safe shutdown of natural gas plant

CHARLOTTE, N.C., Sept. 21, 2018 /PRNewswire/ -- Cape Fear River flooding conditions at the company's L.V. Sutton plant in Wilmington, N.C. have caused breaches in the cooling lake dam surrounding the cooling lake and caused the company to shut down the 625-megawatt natural gas plant there.

The rising river continues to overtop the north end of the cooling lake dam, a surface that is protected by a layer of compacted soil and cement. Water is now exiting the cooling lake through breaches - one large and several smaller - on the southern end of the impoundment. The cooling lake water also flowed into the natural gas plant footprint. Duke Energy photos illustrate the situation at the site this morning. (See photos under "Photo Downloads" at https://news.duke-energy.com/media-kit.)

There are two coal ash basins at the site. The company believes that ash in the 1971 ash basin remains in place behind a steel wall separating the excavation area from the cooling lake. That wall is submerged by flood water, but the earthen portion of the basin dam is about two feet above water and stable. There is no visible ash in the cooling lake, and prior to flooding the ash level was at least five feet below the top of the steel wall.

Cenospheres are moving from the 1971 ash basin to the cooling lake and into the Cape Fear River. Cenospheres are lightweight, hollow beads comprised of alumni and silica that are a byproduct of coal combustion.

Water is more than 10 feet from the earthen dike of the 1984 basin. It is stable and has not been affected. The lined landfill, where most of the site's ash is disposed, has not been affected by the cooling lake and repairs from the hurricane are underway.

Site personnel are supplementing on-site supplies with large stone and other materials, engineering experts are moving to the site and personnel continue to develop and activate repair plans.

Given the historic level of flooding on the river, there is little to no chance that cooling lake water will contribute to a measurable change to water levels in the area.

Sutton Lake is an 1,100-acre man-made reservoir constructed in 1972 to supply cooling water to the Sutton power plant. The cooling lake does not store coal ash.

Duke Energy

Headquartered in Charlotte, N.C., Duke Energy (NYSE: DUK) is one of the largest energy holding companies in the U.S., with approximately 29,000 employees and a generating capacity of 49,500 megawatts.

The company's Electric Utilities and Infrastructure unit serves approximately 7.6 million retail electric customers in six states ? North Carolina, South Carolina, Florida, Indiana, Ohio and Kentucky.

Its Gas Utilities and Infrastructure unit distributes natural gas to approximately 1.6 million customers in five states ? North Carolina, South Carolina, Tennessee, Ohio and Kentucky. Its Commercial Renewables unit operates a growing renewable energy portfolio across the U.S.

More information about the company is available at duke-energy.com. The Duke Energy News Center includes news releases, fact sheets, photos, videos and other materials. Duke Energy's illumination features stories about people, innovations, community topics and environmental issues. Follow Duke Energy on Twitter, LinkedIn, Instagram and Facebook.

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SOURCE Duke Energy