The Environmental Protection Agency took the unusual step of revoking a permit Thursday for the country's largest surface mine, a setback for the controversial practice of "mountaintop removal" that helps produce 10 percent of the nation's coal.
The 2,300-acre operation at the Mingo Logan Coal Co.'s Spruce No. 1 coal mine in West Virginia has been mired in litigation since 1998.
The EPA's decision could affect dozens of other mining projects across Appalachia, where firms have been blasting the peaks off mountains for years to reach coal seams and then depositing the remaining rubble in surrounding valleys.
While the federal government issued permits for hundreds of these activities under the Clinton and George W. Bush administrations, the EPA adopted new environmental guidelines in April and is now reviewing 33 other pending permits.