HARRIMAN, Tenn. - Millions of yards of ashy sludge broke through a dike at TVA's Kingston coal-fired plant Monday, covering hundreds of acres, knocking one home off its foundation and putting environmentalists on edge about toxic chemicals that may be seeping into the ground and flowing downriver.
One neighboring family said the disaster was no surprise because they have watched the 1960s-era ash pond's mini-blowouts off and on for years.
About 2.6 million cubic yards of slurry - enough to fill 798 Olympic-size swimming pools - rolled out of the pond Monday, according to the U.S. Environmental Protection Agency. Cleanup will take at least several weeks, or, in a worst-case scenario, years.
The ash slide, which began just before 1 a.m., covered as many as 400 acres as deep as 6 feet. The wave of ash and mud toppled power lines, covered Swan Pond Road and ruptured a gas line. It damaged 12 homes, and one person had to be rescued, though no one was seriously hurt.
Much remains to be determined, including why this happened, said Tom Kilgore, president and CEO of the Tennessee Valley Authority.
"I fully suspect that the amount of rain we've had in the last eight to 10 days, plus the freezing weather ... might have had something to do with this," he said in a news conference Monday on the site.
The area received almost 5 inches of rain this month, compared with the usual 2.8 inches. Freeze and thaw cycles may have undermined the sides of the pond. The last formal report on the condition of the 40-acre pond - an unlined, earthen structure - was issued in January and was unavailable Monday, officials said.
Neighbors Don and Jil Smith, who have lived near the pond for eight years, said that nearly every year TVA has cleaned up what they termed "baby blowouts."
Ashen liquid similar to that seen on a much larger scale in Monday's disaster came from the dike, they said.
"It would start gushing this gray ooze," said Don Smith, whose home escaped harm. "They'd work on it for weeks and weeks.
"They can say this is a one-time thing, but I don't think people are going to believe them."
The U.S. Coast Guard, EPA, Tennessee Emergency Management Agency and Tennessee Department of Environment and Conservation were among agencies that responded to the emergency.
Toxic irritants possible
Coal is burned to produce electricity at the Kingston Fossil Plant, notable for its tall towers seen along Interstate 40 near the Harriman exit in Roane County.
Water is added to the ash, which is the consistency of face powder, for pumping it to the pond. The ash is settled out in that pond before the sludge is moved to other, drier ponds, Kilgore said.
Coal ash can carry toxic substances that include mercury, arsenic and lead, according to a federal study. The amount of poisons in TVA's ashy wastes that could irritate skin, trigger allergies and even cause cancer or neurological problems could not be determined Monday, officials said.
Viewed from above, the scene looked like the aftermath of a tsunami, with swirls of dirtied water stretching for hundreds of acres on the land, and muddied water in the Emory River.
The Emory leads to the Clinch, which flows into the Tennessee.
Workers sampled river water Monday, with results expected back today, but didn't sample the dunelike drifts of muddy ash.
That could begin today, officials said, and the potential magnitude of the problem could make this a federally declared Superfund site. That would mean close monitoring and a deep, costly cleanup requiring years of work.
"We'll be sampling for metals in the ground to see what kind of impact that had," said Laura Niles, a spokeswoman for the EPA in Atlanta.
"Hopefully, it won't be as bad as creating a Superfund site, but it depends on what is found."
Stephen Smith, with the Southern Alliance for Clean Energy in Knoxville, said those concerned about water and air quality have tried for years to press for tighter regulation of the ash.
The heavy metals in coal - including mercury and other toxic substances - concentrate in the ash when burned, he said.
"You know where that is now," he said. "It's in that stuff that's all over those people's houses now."
Chemicals and metals from coal ash have contaminated drinking water in several states, made people and animals sick in New Mexico, and tainted fish in Texas and elsewhere, according to Lisa Evans, an attorney with Earthjustice, a nonprofit national environmental law firm that follows the issue.
"It's discouraging because this is an easy problem to fix," she said.
Ash could be recycled by using it to make concrete and at the very least should be placed in lined, state-of-the-art landfills, she said.
Plant is still operating
TVA's Kilgore said that chemicals in the ash are of concern, but that the situation is probably safe. The power plant is still operating, sending the ash to a larger pond on the site.
"There are levels of chemicals in there that we are concerned about," Kilgore said. "We don't think there's anything immediate of danger because most of that's contained, but that's why we have sampling folks out."
Officials were monitoring a water intake that serves Kingston City and is only a few miles downstream from the Kingston plant, but said no problem had been noted there as of Monday afternoon.
The power producer, which oversees the Tennessee River system, had slowed river flow in the area, releasing less water from key dams, so the pollution might be better contained for possible cleanup.
TVA has insurance for an event like this, spokeswoman Barbara Martucci said, but what the cleanup cost is and how much insurance will pay remains to be determined.
Otherwise, ratepayers in Tennessee could bear much of the costs. TVA provides virtually all the electricity in the state, along with parts of six others.