AUDIE CORNISH, HOST:
A coal ash spill in North Carolina has dumped about 82,000 tons of waste into a nearby river. A broken storm-water pipe caused what is the third biggest coal ash spill in U.S. history and the pipe is still leaking.
Jeff Tiberii of North Carolina Public Radio reports that officials say drinking water downstream is safe, but environmental questions remain.
JEFF TIBERII, BYLINE: The Dan River stretches more than 200 miles from North Carolina, through Virginia and into the Atlantic Ocean. It's home to all sorts of wildlife and a popular destination for fishermen and kayakers.
UNIDENTIFIED WOMAN: Show you what it looks like.
JENNIFER EDWARDS: The river is a different color today.
TIBERII: Jennifer Edwards is with the Dan River Basin Association. Over the weekend at an old power plant, a storm-water pipe that goes under a coal ash pond broke. It sent the equivalent of 30 Olympic-sized swimming pools filled with ash into the Dan River. She's about a mile downriver from the spill and uses a plastic pitcher to check the water and sediment.
EDWARDS: Yesterday, it was a decided charcoal gray. Today, it's more of a khaki brown. So that may indicate that the suspended solids are either settling down or washing out.
TIBERII: Edwards says it's too early to know what the effect will be on fish, bugs and plant life in the river. Duke Energy stopped using its coal-fired power plant near the river in 2012. When coal is burned to generate energy, the ash byproduct is created and stored in huge ponds. The ash contains arsenic, uranium and other potentially toxic substances.
Paige Sheehan is a Duke spokeswoman. She says the spill is continuing but is significantly less than it was Sunday.
PAIGE SHEEHAN: Focus today is on attacking the repair from two fronts - from the river front and from the land front - and also pulling water out of the area around the hole in the storm drain. It is exposed now.
TIBERII: That pipe does not serve the coal ash pond, it simply ran under it. Sheehan thinks crews can get it stopped in the next few days. Meanwhile, the river provides drinking water to Danville, Virginia, population about 43,000 people.
Barry Dunkley is director of water and wastewater treatment there. He says their tests show nothing unusual yet.
BARRY DUNKLEY: All the water is safe to drink. We still are seeing the gray color and we still have the coal ash in the river, in the raw water, but we're able to treat it.
TIBERII: Dunkley is running multiple tests. So, too, is Duke Energy and state officials in North Carolina. The spill is far smaller than a massive coal ash spill that happened in 2008 when part of a dam broke in Tennessee. Once the broken pipe here is sealed, Duke will have to figure out what to do about another storm-water pipe that runs under the same coal ash pond.
For NPR News, I'm Jeff Tiberii in Eden, North Carolina.