In their new ruling, board members found that a new ICG "contingency plan" for dealing with acid mine drainage was "inadequate."
"The board finds that the contingency plan is open-ended with no clear limits, timelines or monitoring regime required by the permit," the board said.
Board members found the plan did not explain how material damage to streams would be identified, and included no enforceable monitoring requirements that would allow pollution to be controlled.
Gene Kitts, senior vice president of ICG, said the company was "obviously disappointed" by the board ruling and would "be closely reviewing the ruling to determine the best course of action to address their concerns."
"We believe the Tygart No. 1 mine plan is environmentally responsible and meets all state and federal regulatory requirements," Kitts said. "That makes us confident that the perceived deficiencies in the WVDEP mining permit can be appropriately resolved and that development of our planned Tygart No. 1 underground mine can proceed."
But Cindy Rank, mining chairwoman for the West Virginia Highlands Conservancy, praised the board's ruling and said it supports citizen concerns about water pollution in the acid-producing seams of northern West Virginia.
"These deep mines in the acidic areas are really time bombs waiting to happen," Rank said Thursday. "We really have to prevent acid mine drainage from happening, not try to clean it up later."