Duke Energy: Dam breached at Wilmington plant, coal ash basins affected

Duke Energy's L.V. Sutton Energy Complex from I-140 on Sept. 21, 2018. (Photo: Marty Doty/WWAY)

WILMINGTON, NC (WWAY) — Duke Energy says flooding at the L.V. Sutton plant near Wilmington has led the company to shut down the 625-megawatt natural gas plant.

In a news release, Duke says the rising Cape Fear River has overtopped the north end of the dam on Lake Sutton. The company says water is exiting the cooling lake through one large and several smaller breaches on the southern end. Water from the lake also flowed into the natural gas plant.

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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 Duke says the earthen portion of the basin dam is about two feet above water and stable. The company says there is no visible ash in the cooling lake, and before the flooding the ash level was at least five feet below the top of the steel wall.

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

Duke says water is more than 10 feet from the earthen dike of the 1984 basin. The company says 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, according to the news release.

Crews 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, Duke says.

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.