It looks like the surface of the moon. The black sludge that poured out of a Tennessee coal burning plant now covers entire neighborhoods.
"It's just scary," said Chris Copeland, a resident of Harriman, Tenn. "I have two young girls, and I'm afraid for their health."
Like dozens of families in the area, the Copelands watched as their home was submerged in a wave of sludge -- the waste product created when coal is burned for electricity.
An enormous amount of coal ash residue -- the sludge -- spread across entire communities in the area this week after a massive wall around a retention pond near a coal plant gave way.
The irony is that the sludge that soiled this area was part of an effort to make burning coal more environmentally friendly.
The worry now among environmentalists and homeowners is over what is in the sludge and whether it contains mercury and arsenic that could potentially contaminate the water supply and dry into harmful dust particles in the air.
"This stuff is a witch's brew of toxic heavy metals that needs to be contained and controlled," said Stephen Smith, executive director of the Southern Alliance for Clean Energy.
The ash has spilled into a river that feeds a waterway that supplies drinking water to millions of people. Representatives from the company that owns the coal plant insisted today there is nothing to worry about.
"The water is safe," said Amanda Ray of the Tennessee Valley Authority. "The environment is safe. And we're going to clean this up."
That clean-up work has already begun and preliminary tests by state regulators show the drinking water is safe. They will continue to monitor the area regularly.
"It is imperative to manage the site to minimize any impact that this could have both on aquatic habitat and human health," said Paul Sloan of the Tennessee Department of Environment and Conservation.
Federal officials are also running tests and say it is too early to know exactly what materials are in the coal sludge.
Environmentalists worry about possible long- term health effects, such as cancer and respiratory problems.
"This is an environmental disaster, and to call it anything else is absolutely false," says Smith.
The Copeland family doesn't know who to believe.
"People tell you all the time things are safe, and later down the road you find out that they aren't," Copeland said.
For the Copelands and other families, the coal plant has long been a source of electricity and jobs.
Now it is a source of grave concern.