A wall holding back 80 acres of sludge from a coal plant in central Tennessee broke this week, spilling more than 500 million gallons of waste into the surrounding area, according to a report by CNN (www.cnn.com). The spill damaged 15 homes — three of which were declared uninhabitable — and forced the evacuation of all residents of Kingston, Tenn.

Environmental Protection Agency (www.epa.gov) officials are investigating whether the spill represents a toxic threat to the local area water supply. Officials estimate the cleanup will take four to six weeks.

The Tennessee Valley Authority operates the plant from which the spill occurred.

To read the full CNN report on this story, click here.