Lesley Stahl on Sunday's 60 Minutes did an in-depth look at the problems with the by-products of coal production, commonly known as coal ash. Coal ash contains many toxic metals, including arsenic, which unchecked, can leak into ground water and be extremely hazardous to breathe. Stahl starts with a look at devastating coal ash spill that engulfed homes and destroyed whole communities in Tennessee in 2008 with a flood of a billion gallons of toxic sludge. This was the largest environmental disaster of its kind in the US. This disaster brought the issue of coal ash to the national spotlight, and Stahl moves on to how coal ash is not labeled a hazardous waste by the EPA, and is currently being used as filler in everything from golf courses to carpeting in schools to kitchen counters. Watch to the end when Stahl presses a power industry lobbyist about whether the material is being currently being handled safely and can't get a straight answer.