* Move shuts one of largest U.S. mountaintop coalmines
* Obama admin has been cracking down on mountaintop mines
* Arch says will fight for the permit in court
(Adds details, Arch comment, byline)
By Timothy Gardner
WASHINGTON, Jan 13 (Reuters) - The Obama administration revoked a permit on Thursday for Arch Coal Inc's ACI.N proposed Spruce 1 mountaintop coal mine in West Virginia, effectively shutting one of the biggest in the United States.
"The proposed Spruce No. 1 Mine would use destructive and unsustainable mining practices that jeopardize the health of Appalachian communities and clean water on which they depend," said Peter Silvan, an assistant administrator for water, at the Environmental Protection Agency.
The EPA's final ruling under the Clean Water Act came after a scientific study, a public hearing, and a review of more than 50,000 public comments, the agency said.
The U.S. Army Corps of Engineers had approved a permit for the mine in 2007, but it had not been fully constructed. [ID:nN15219373].
Lawmakers from West Virginia said the EPA's move would hurt the state's economy.
"Today's EPA decision is not just fundamentally wrong, it is an unprecedented act by the federal government that will cost our state and our nation even more jobs during the worst recession in this country's history," Senator Joe Manchin, a Democrat, said in a release.
Senator Jay Rockefeller, also a Democrat, wrote a letter to President Barack Obama, that said: "as a nation we must not fall into the trap of forcing unnecessary choices between protecting the environment and having good paying jobs that support energy independence."
St. Louis-based Arch said it would vigorously defend the permit in court. EPA's revocation of the permit blocks an additional $250 million in investment and 250 jobs, the company said.
It was the latest move by the Obama administration to crack down on mountaintop mining, in which companies blast high peaks to uncover coal seams and often toss the resulting rubble into valleys.
Obama's EPA started requiring big carbon dioxide polluters, such as coal-fired power plants, to hold permits for emitting the planet-warming gas.
The administration's policy to get tough on coal could face stiffer opposition in Congress after Republicans took control of the House of Representatives and gained seats in the Senate in last year's elections.
Environmentalists applauded the EPA action.
"A full veto of the proposed Spruce No. 1 Mine is a true victory for the communities nearby, and for all Americans across the country who are fighting to protect our precious natural resources from industrial pollution," said Joan Mulhern, senior legislative counsel for Earthjustice.
"While this is only one mine of many, we hope this veto will be the beginning of the end of the devastating practice of mountaintop removal mining by bringing the fundamental legal protection of the Clean Water Act to the whole Appalachian region, once and for all."
Shares in Arch were up more than 1.4 percent on Thursday at $34.63 in midday trading on the New York Stock Exchange. (Reporting by Timothy Gardner; Editing by Marguerita Choy)