KNOXVILLE, Tenn. (AP) — The Tennessee Valley Authority has raised its estimate for cleaning up a huge coal ash spill to $1.2 billion and partly blamed the cleanup for its third-quarter loss of $167 million.

The authority, the nation's largest public utility, gave the new estimate Friday in a filing to the Securities and Exchange Commission.

On Dec. 22, nearly 5.4 million cubic yards of toxic ash breached a holding pond at a coal-fired power plant near Kingston.

No one was injured, but millions of tons of ash and sludge swept into a river, damaged two dozen homes, covered 300 acres, raised health concerns in the area and brought Congressional attention to the lack of regulation of similar sites throughout the country.