A retaining wall at the Tennessee Valley Authority's Kingston coal-fired power plant collapsed early Monday morning, causing 2.6 million cubic yards of fly ash to be spilled across hundreds of acres.
The Kingston Steam Plant in Harriman, about 50 miles west of Knoxville, at the confluence of the Emory and Clinch Rivers is owned and operated by the nation's largest public utility.
The wet gray sludge buried about 400 acres six feet deep. One house was torn from its foundations, and 11 other homes were damaged and evacuated. No injuries or fatalities have been reported.
TVA estimates that the cleanup could take weeks to complete and says long-term plans are being developed. Environmentalists warn that fly ash contains toxins - mercury, arsenic, and lead among others - that could seep into the ground and flow downriver.
TVA provided hotel rooms, meals, transportation and other immediate needs for affected residents who were not able to occupy their homes Monday night. Additional assistance is being provided by TVA as needed by affected residents. Electricity, gas and water have been restored to all homes in the area that are habitable, the TVA said.
The Swan Pond Road past the Kingston plant remains closed except for residents who live in the area whose homes are habitable. There is no estimated timeline for when the road will be reopened.
TVA Police are assisting local law enforcement with maintaining security for the homes in the affected area.
Kingston is one of TVA's larger fossil plants. It generates 10 billion kilowatt-hours of electricity a year, enough to supply the needs of about 670,000 homes in the Tennessee Valley.
"This holiday disaster shows that there really isn't such a thing as a clean coal plant," said Chandra Taylor, staff attorney for the Southern Environmental Law Center.
"From mountaintop removal mining to smokestacks spewing soot and smog to ash ponds full of toxins, coal power is dirty - plain and simple. Nobody wants to find coal in their Christmas stocking, let alone coming through their home and polluting their river," she said.
TVA says sampling of water downstream of the plant will continue to assess the possible effects on water quality. TVA continues to manage river flows on the Clinch and Tennessee Rivers to minimize downstream movement of the ash.
Staff at TVA's other 10 coal-fired power plants have made visual inspections of the ash retention dikes to note any changes in conditions. The ash containment areas at all TVA's plants undergo a formal inspection annually and other inspections on a quarterly and daily basis, said the government company.
"The United States Environmental Protection Agency should immediately establish national safeguards for the disposal of coal wastes and enforceable regulations," said Taylor. "At a minimum, these safeguards should include siting restrictions, structural requirements and long-term financial assurance to clean up any resulting pollution."