SPENCER ó Buck Steam Station released about 85,000 gallons of river water to the Yadkin River Friday during a brief wastewater discharge lasting about 40 minutes.
As the new combined cycle plant was filling a water filtration basin for the first time, a valve malfunctioned, allowing river water to flow backward to the Yadkin River, Duke Energy said in a press release.
The water released to the river contained no coal combustion byproducts or sanitary waste, Duke said. It was primarily river water.
The 85,000 gallons of river water contained fewer than two gallons of chemicals used in water filtration, according to the release.
When the situation was discovered, workers manually closed a valve. A modification will be installed to ensure a repair that will prevent a similar incident in the future.
The N.C. Department of Environment and Natural Resources was notified. No environmental impact or fish mortality was observed from this event, Duke said.
State regulations require the owner or operator of any wastewater collection or treatment system ó other than those systems that collect or treat municipal or domestic wastewater ó issue a news release when a wastewater release of 1,000 gallons or more reaches surface waters.
Duke Energy Carolinas owns nuclear, coal-fired, natural gas and hydroelectric generation and provides about 19,000 megawatts of owned electric capacity to about 2.4 million customers in a 24,000-square-mile service area of North Carolina and South Carolina.