KINGSTON, Tenn. — What may be the nation's largest spill of coal ash lay thick and largely untouched over hundreds of acres of land and waterways Wednesday after a dam broke earlier this week, as officials and environmentalists argued over its toxicity.
Federal studies have long shown coal ash to contain significant quantities of heavy metals like arsenic, lead and selenium, which can cause cancer and neurological problems. But with no official word on the dangers of the sludge in Tennessee, displaced residents spent Christmas Eve worried about their health and their property.
The spill took place at the Kingston Fossil Plant, a Tennessee Valley Authority generating plant about 40 miles west of Knoxville on the Emory River, which feeds into the Clinch and then the Tennessee River.
"They're giving their apologies, which don't mean very much," said Holly Schean, a waitress whose home, which she shared with her parents, was swept off its foundation when millions of cubic yards of ash breached a retaining wall early Monday morning. The TVA has not yet declared the house uninhabitable, she said. "I don't need your apologies, I need information."
As the TVA downplayed the risks, the spill reignited a debate over whether the government should regulate coal ash as a hazardous material. Similar ponds and mounds of ash exist at hundreds of coal plants.
The TVA has issued no warnings about the potential chemical dangers of the spill, saying there was as yet no evidence of toxins. "Most of that material is inert," said Gilbert Francis Jr., a TVA spokesman. "It does have some heavy metals within it, but it's not toxic or anything."
Francis said that contaminants in water samples taken near the spill site and at the intake for Kingston, 6 miles downstream, were within acceptable levels.
But a draft report last year by the Environmental Protection Agency found that fly ash, a byproduct of burning coal, contains significant amounts of carcinogens and retains the heavy metal present in coal in far higher concentrations. The report said that the concentrations of arsenic to which people might be exposed through drinking water contaminated by fly ash could increase cancer risks several hundredfold.
The breach occurred when an earthen dike gave way, regurgitating a sea of muck, 4 to 6 feet thick. Where the Clinch River joins the Tennessee, a clear demarcation was visible between the soiled waters of the former and the clear brown broth of the latter.
By afternoon, dump trucks were depositing rock into the river in a race to blockade it before an impending rainstorm washed more ash downstream.
The contents of coal ash can vary widely depending on the source, but one study found that the mean concentrations of lead, chromium, nickel and arsenic are three to five times higher in the Appalachian coal that is mined near Kingston than in Rocky Mountain or Northern Plains coal.
Stephen Smith, the executive director of the Southern Alliance for Clean Energy, said it was mind-boggling that officials had not warned nearby residents of the dangers.
He and other environmentalists warned that another danger would arise when the muck dried out and became airborne.
Despite reports from recreational fishermen and television news video of a large fish kill downstream, Francis said the TVA's environmental team had not encountered any dead fish. Near the plant, environmental advocates went door to door telling residents that boiling their water, as officials had suggested, would not remove heavy metals.
Environmentalists pointed to the accident as proof of their assertion that there is no such thing as "clean coal," noting two factors that may have contributed to the scale of the disaster.
First, as coal plants have gotten better at controlling air pollution, the toxins that would have been spewed into the air have been shifted to solid byproducts like fly ash, and such waste has increased dramatically.
Second, the Kingston plant had little room to grow and simply piled its ash higher, though officials said the pond that breached was not over capacity.
Environmental groups have long pressed for coal ash to be buried in lined landfills to prevent the leaching of metals, a recommendation borne out by the 2006 EPA report. An above-ground embankment is not an appropriate storage site for fly ash, said Tom FitzGerald, the director of nonprofit Kentucky Resources Council and an expert in coal waste. "I find it difficult to comprehend that the state of Tennessee would have approved that as a permanent disposal site," he said.