Just days after Al Gore and a bunch of environmental organisations launched a “Reality Coalition” campaign to tell the American public that there is no “clean coal” they might have gotten their best advertisement, ever.

Last month a coal ash dam in Harriman, East Tennessee, USA, ruptured and sent out billions of gallons of toxic sludge across a 300 acres big area, even knocking one home off its foundation. According to the Environmental Protection Agency (EPA) these coal ash damns can reach up to 1,500 acres and contains heavy metals like arsenic, lead, mercury and selenium which the federal agency considers to be “a threat to water supplies and human health.”

“This spill shows that coal can never be ‘clean,’” said Kate Smolski, Senior Legislative Coordinator for Greenpeace. “If the Exxon Valdez was a symbol of pollution 20 years ago, the Tennessee Coal Spill of 2008 is the symbol of it today.”

Elliott Negin of the Union of Concerned Scientists said that “this disaster shows that the term ‘clean coal’ is an oxymoron. It’s akin to saying ’safe cigarette.’ Clean coal doesn’t exist.”

The New York Times reports that there are hundreds of more coal ash dams like the one in the East Tennessee and that they are “not subject to any federal regulation, which experts say could have prevented the spill, and there is little monitoring of their effects on the surrounding environment.”

“Every facility like this is supposed to have a spill contingency plan to prevent this kind of disaster,” said Rick Hind, Greenpeace Legislative Director. “The authorities need to get to the bottom of what went wrong and hold the responsible parties accountable.”

Watch MSNBC’s coverage of the coal disaster:

Watch aerial footage of the coal disaster:

So, will this disaster be the end of the “clean coal” lie?