EDEN, N.C. — Duke Energy did not know how much coal sludge its dormant power plant in Eden had spewed into the Dan River or for how long it had been leaking when company officials started alerting municipalities downstream Sunday evening, leaving city officials flatfooted in their efforts to protect drinking water supplies.
In Danville, Va., the first municipality downstream affected by the spill, the city provides water to about 17,500 customers, about 15 miles from Eden. City Manager Joe King suggested Wednesday that the initial heads-up from Duke left room for improvement.
“Initially, the information was sketchy. It was not of sufficient detail for us to fully respond or be prepared,” King said.
Eden was not affected because the city gets its water upstream of the spill, officials said.
Duke alerted Danville emergency services officials around 6 p.m. Sunday, officials said, saying that a spill had occurred. The key pieces of missing information: When the spill had started and how much had leaked into the river, officials said.
By Monday morning, Danville officials had a better idea.
“The whole river turned gray,” said Barry Dunkley, the division director of water and wastewater treatment for Danville Utilities. “We knew then that it was a pretty hefty amount.”
Since Monday, he said, Duke has provided ample information about the spill.
Erin Culbert, a Duke spokeswoman, said the company acted as quickly as possible.
“We contacted the city of Danville emergency management early in the event on Sunday so they would be aware and could plan for any potential impacts. Further analysis was needed Monday to accurately estimate the volumes of water and ash released, and we provided that to the public as soon as it became available,” she said.
Coal ash, the waste from coal combustion, usually contains arsenic, mercury, lead and several other heavy metals.
Duke reported Tuesday that a 4-foot storm-water pipe under a 27-acre ash pond at the retired coal plant broke Sunday, allowing the toxic waste from coal combustion to spill into the river. The company estimated that 50,000 to 82,000 tons of ash and 24 to 27 million gallons of basin water entered the river. That’s enough to fill about 32 Olympic-size swimming pools.
Standing between Danville’s drinking water and the coal waste flowing in the Dan River are the city’s wastewater treatment filters and the detergents its treatment plant uses to scrub the raw water of contaminants.
Drinking water has been safe all along, city officials said.
Since Sunday, the raw water entering the city’s intake has contained coal ash, though the concentration level is decreasing, said Arnold Hendrix, the city spokesman. Test samples of the raw water at the city’s intake also show the presence of arsenic.
“We have been able to remove the ash through routine treatment. No special treatment has been required. In addition, the first test samples of the treated water entering our distribution levels show routine treatment has reduced the level of arsenic to non-detectable levels. We continue testing as a precautionary measure, and we expect additional test results on Thursday,” Hendrix said.