Estimates for the amount of thick sludge that gushed from a Tennessee coal plant last week have tripled to more than a billion gallons, as cleanup crews try to remove the goop from homes and railroads and halt its oozing into an adjacent river.
TVA officials originally said the cleanup would take four to six weeks. Now they say they aren't sure.
The sludge, a byproduct of the ash from coal combustion, was contained at a retention site at the Tennessee Valley Authority's power plant in Kingston, about 40 miles east of Knoxville. The retention wall breached early Monday, sending the sludge downhill and damaging 15 homes. All the residents were evacuated, and three homes were deemed uninhabitable, according to the TVA.
TVA's initial estimate for the spill was 1.8 million cubic yards or more than 360 million gallons of sludge. By Friday, the estimate reached 5.4 million cubic yards or more than 1 billion gallons -- enough to fill 1,660 Olympic-size swimming pools.
Environmental advocates say the ash contains concentrated levels of mercury and arsenic.
The plant sits on a tributary of the Tennessee River called the Clinch River. At least 300 acres of land has been coated by the sludge, a bigger area than the 1989 Exxon Valdez oil spill.
A spokesman for TVA, a federal corporation and the nation's largest public power company, said the agency has never experienced a spill of this magnitude.
"There's a lot of ash there," spokesman John Moulton said Friday. "We are taking this very seriously. It is a big cleanup project, and we're focused on it 24 hours a day."
