The latest in a series of federal court rulings on mountaintop coal mining in Appalachia came down firmly on the side of the coal industry on Friday.
The ruling, by the United States Court of Appeals for the Fourth Circuit, in Richmond, Va., overturned a 2007 decision that supported environmentalists' claims that the Army Corps of Engineers had improperly issued permits for several such mining operations.
For more than a decade, environmental campaigners have tried various legal avenues to fight the mining technique, a form of strip-mining that blasts the tops off mountains and dumps the leftover rock in valleys, burying streams.
After Friday's ruling, environmental groups urged President Obama to follow up on statements he had made during his campaign that were critical of mountaintop mining by reversing Bush administration policies intended to expand the practice.
Jennifer Chavez, a lawyer at Earthjustice, an environmental law firm that is a plaintiff in the case, called the decision "a landmark in a bad way," that could unleash a burst of new mining.
"There's a big backlog of permits, something like 80 or 90, we hear from our partners in West Virginia," Ms. Chavez said. "We're afraid there's going to be just a floodgate opening."
But Luke Popovich, a spokesman for the National Mining Association, said the industry was "delighted" and called the ruling "a sweeping vindication."
Mr. Popovich said that the 2007 ruling had resulted in a backlog of mining permits and created uncertainty that was harming the economy in the region.
The case, heard by three judges on the federal appeals panel, focused on whether the corps had been too liberal in allowing mining companies to bury streams as long as they created settling ponds and promised to transform drainage ditches into artificial streams that, in theory, might filter out contamination. The corps is responsible for preventing actions that could harm waters in the United States.
Among other arguments, the plaintiffs contended that the corps had not demonstrated scientifically that the ponds and artificial streams were effective.
The ruling said the corps had the expertise and discretion to issue such permits.
The mining association says that mountaintop mining in Appalachia produces about 10 percent of all coal mined in the United States and 40 percent of the coal mined in West Virginia and Kentucky.
Environmentalists have recently intensified their campaigns against mountaintop mining, arguing that it causes water contamination that is harmful to the residents of the valleys and that the expanding use of coal increases emissions of carbon dioxide, the main heat-trapping gas linked to global warming.
In the last months of the Bush administration, the Interior Department issued new rules intended to ease rules governing buffer zones along waterways, a change that could expand the mining method.