Wall breach sends sludge downhill , causing damage to 15 homes . Environmental Protection Agency officials are on the scene and expect the cleanup to to take four to six weeks . Spokesman says 400 acres are coated by more than 500 million gallons of sludge . Area affected is bigger than Exxon Valdez oil spill , spokesman says . Comment:
Wall breach sends sludge downhill , causing damage to 15 homes . Spokesman says 400 acres are coated by more than 500 million gallons of sludge . Area affected is bigger than Exxon Valdez oil spill , spokesman says . Comment: