UPDATE 8/23/12 @ 11:30 p.m.
CHARLESTON, W.Va. (AP) - A federal judge wants more time to decide if he'll block a Clean Water Act permit for a Logan County coal mine while environmentalists appeal the permit to a higher court.

U.S. District Judge Robert Chambers in Huntington said Thursday that he'd continue a legal stay on the permit for the Alpha Natural Resources mine until he can consider new legal briefs and arguments.

Chambers said he might not rule until later in the week.

The Ohio Valley Environmental Coalition and others had challenged the permit at Virginia-based Alpha's Highland Reylas surface mine.

Earlier this month Chambers ruled in favor of the U.S. Army Corps of Engineers and Alpha.

The groups hope to appeal the decision to the 4th U.S. Circuit Court of Appeals.

The Associated Press says Virginia-based Alpha wants a federal judge to disallow studies co-authored by West Virginia University researcher Michael Hendryx.

Hendryx found people living near mountaintop removal mines have higher cancer and birth defect rates.

The Ohio Valley Environmental Coalition is challenging permits issued to Alpha's Highland Mining for the 235-acre Reylas mine in Logan County. It wants to include evidence of potential human health effects among the objections.

The U.S. Army Corps of Engineers said it anticipated no such effects when it issued a water pollution permit.

Alpha says opponents waited too long to enter the studies, which have nothing to do with the permit.

The Corps said Friday that the permit for the Reylas Surface Mine allows Highland Mining Company to discharge fill material into 13,743 linear feet of waters. It authorizes one valley fill, one sediment pond and several mine-through areas.

The company will be required to restore or create thousands of linear feet of stream channel to mitigate the project's impact.