The regulation is the culmination of six and a half years of work by the Bush administration to make it easier for mining companies to dig more coal to meet growing energy demand and reduce dependence on foreign oil. The U.S. already gets half its electricity from coal.

Environmentalists say the step will accelerate pillage of vast tracts and obliterate hundreds of miles of streams in central Appalachia in the eastern U.S.

“This is a parting gift to the coal industry from this administration,” said Joe Lovett, executive director of the Appalachian Center for the Economy and the Environment in Lewisburg, W.Va. “This is an attempt to make legal what has long been illegal.”

From 1985 to 2001, 724 miles of streams were buried under mining waste, according to the environmental impact statement accompanying the new rule. If current practices continue, another 724 river miles will be buried by 2018.