The U.S. Environmental Protection Agency has proposed to block a Clean Water Act permit for one of the largest mountaintop coal mines in Appalachian history.The Spruce Number 1 mine in Logan County, West Virginia received its permit in 2007. But litigation has delayed the operation since then. And for the first time, the EPA is using its authority under the Clean Water Act to veto a project that’s already been permitted. The agency issued a statement today outlining its concerns about the mine, including the potential loss of seven miles of headwater streams and damage to stream ecosystems.Mine owner Arch Coal issued a statement expressing their disappointment with the decision. The company intends to fight the matter in court.