Aracoma Coal Co. wants to mine 12.5 million tons of coal from the hills around historic Blair Mountain, near Ethel in Logan County.In the process, the Massey Energy subsidiary would bury nearly 3 miles of streams. Over the next eight years, millions of tons of waste rock and dirt would be dumped into Camp Branch and Dingess Run.When it approved the proposal in July, the U.S. Army Corps of Engineers concluded that Aracoma's plan "does not significantly affect the quality of the human environment."On Thursday, three West Virginia environmental groups filed a lawsuit challenging the corps finding.In their suit, the groups argue the effects are massive and warranted a detailed environmental impact study before Aracoma was granted its permit.The 25-page suit launched another major legal attack on mountaintop removal coal mining in Appalachia.If successful, the case could force federal regulators to perform detailed and time-consuming studies before issuing any new mining permits. At the same time, it could require government agencies to more fully examine potential impacts on forests and streams, and consider those before deciding to allow mining."It's painfully obvious that the corps is acting without regard to the law by ignoring the individual, let alone cumulative, effects of valley fills on the natural resources and communities in the coalfields," said Cindy Rank, mining chairwoman for the West Virginia Highlands Conservancy. "The corps isn't bothering to review and evaluate the destruction it is permitting."The conservancy, along with the Ohio Valley Environmental Coalition and Coal River Mountain Watch, filed the suit in U.S. District Court in Huntington. It had not yet been assigned to a judge late Thursday afternoon.The environmental groups are represented by Joe Lovett of the Appalachian Center for the Economy and the Environment and by Stephen Roady and Jennifer Chavez of the Washington-based group Earthjustice.Earlier this week, environmental group lawyers defended on appeal a ruling by U.S. District Judge Joseph R. Goodwin to block the corps from reviewing valley fill proposals through a streamlined "general permit" process.In the new case, the groups argue the corps was wrong to approve Aracoma's mining application through a more detailed "individual permit" review because that review did not include a study called an Environmental Impact Statement, or EIS.The suit also alleges that, in approving the Aracoma permit, the corps violated its own Clean Water Act regulations prohibiting discharges "which will cause or contribute to significant degradation" of streams.In the suit, the groups target Aracoma's Camp Branch Surface Mine. The Massey proposal has already been controversial because of its location near the site of the 1921 Battle of Blair Mountain, which is being considered for the National Register of Historic Places.Massey first obtained a nearly 1,000-acre permit for the operation in July 1991, according to state Department of Environmental Protection records.Since then, the company has at least twice scaled back the size of the proposal to appease state and federal regulators.Three of the original eight valley fills have been eliminated, including one specifically to avoid part of the area being considered for the historic site, records show. The length of stream affected has dropped by about 20 percent, the records show.Still, the U.S. Environmental Protection Agency, the state Division of Natural Resources and the federal Fish and Wildlife Service expressed reservations about the mining proposal.In their suit, the environmentalists say the corps failed to take the "hard look" at these potential impacts that is required by the National Environmental Policy Act, or NEPA.Under NEPA, federal agencies are required to prepare environmental impact statements "for every major federal action significantly affecting the quality of the human environment."Corps of Engineers spokeswoman Candy Walters referred calls to the U.S. Department of Justice. A spokeswoman there did not immediately return a phone call.