Over the weekend at an old power plant in Eden, N.C., a stormwater pipe that goes under a coal ash pond broke, sending about 82,000 tons of ash into the Dan River.
The 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.
On Wednesday, Jennifer Edwards, with the Dan River Basin Association, was checking the water and sediment about a mile downriver from the spill.
"Yesterday, it was a decided charcoal gray; today it's more of a khaki brown," she says. "So that may indicate that the suspended solids are either settling down or washing out."
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 the coal-fired power plant 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, a spokeswoman for Duke Energy, says the spill is continuing, but significantly less so than it was on Sunday.
The focus Wednesday, she says, "is on attacking the repair from two fronts from the river front and from the land front," she says. "And also pulling water out of the area around the hole in the storm drain it is exposed now."
The stormwater pipe doesn't serve the coal ash pond; it simply runs under it. Sheehan thinks crews can get it stopped in the next few days. Meanwhile the river provides drinking water to Danville, Va. population about 43,000. Barry Dunkley, director of water and wastewater treatment there, says their tests show nothing unusual yet.
"All the water is safe to drink," he says. "We still are seeing the gray color, and we still have the coal ash in the river and the raw water, but we're able to treat it."
Dunkley is running multiple tests. So too are Duke Energy and state officials in North Carolina.
The spill is far smaller than the massive coal ash spill 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 stormwater pipe that runs under the same coal ash pond.