A pipe at the bottom of a 27-acre pond in North Carolina has sprung a leak, spewing tons of coal ash into the Dan River – a source of drinking water for Danville, Va., a town 20 miles upstream.

Since the leak was spotted by a security guard on Sunday, more than 82,000 tons of ash have mixed into the pond, creating a toxic sludge among the 27 million gallons of water that have poured into the Dan River, according to an Associated Press report.

The AP also reported there is no timetable for when the leak will be fully contained, but since the pond has since been emptied, the flow is much lighter than before.

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Still, Danville residents are worried as they wait for test results that will determine the hazards to their drinking water or surrounding wildlife.

Canoe guide Brian Williams told the AP he is scared about the future of the waterway.

“How do you clean this up?” he asked. “Dredge the whole river bottom for miles? You can’t clean this up. It’s going to go up the food chain, from the filter feeders, to the fish, to the otters and birds and […]