Tests to show water safety after coal ash spill in North Carolina

WINSTON-SALEM, North Carolina (Reuters) - As many as 82,000 tons of ash have spilled into a river after a pipe break at a retired coal plant in North Carolina, and state environmental officials plan to release test results on Thursday that gauge hazards to the water quality.

The leak was discovered on Sunday at a Duke Energy power plant in Eden. The company said the broken stormwater pipe under a 27-acre ash pond released enough coal ash into the Dan River to fill between 20 and 32 Olympic-size swimming pools.

No immediate threat to drinking water was reported. The state's Department of Environment and Natural Resources was conducting tests to determine if the water was safe in the river where fishing and canoeing are popular activities.

An agency spokeswoman said the latest results on suspended solids, sulfates and nutrients in water near the spill site were expected to be made public on Thursday.

Hundreds of workers have been at the site this week trying to stop the leak and permanently seal the broken pipe, Duke Energy said in a statement. A spokeswoman said there was no indication of when the spill, which was visible several miles downstream, would be fully contained.

"It has slowed since the break was discovered," spokeswoman Meghan Musgrave said. "Our focus remains on public safety and fixing this break in the pipe."

Duke Energy, the country's largest electric power provider, retired the Eden coal plant in 2012. No coal ash has been produced at the site since then.

The plant was built in the 1940s, and the stormwater pipe was in place before the ash basin was extended over it, Musgrave said. The ash pond stored the waste produced by coal burning.

The Waterkeeper Alliance, an international group of water advocates, said the coal ash spill is "the latest in a series of wake-up calls" about the public health and environmental threats of leaking ash ponds.

"Waterkeepers call on Duke Energy to put the safety of the public and our waterways first by closing all of their ash ponds before the next disaster happens," the organization said in a statement.

(Reporting by Colleen Jenkins; editing by Andrew Hay)