A federal appeals court today decided against rehearing an environmental group challenge to U.S. EPA's decision not to regulate some mercury and other hazardous air emissions from gold mining and processing operations.

Today's action by the U.S. Court of Appeals for the District of Columbia Circuit means a Nov. 9 ruling in favor of EPA will stand.

A three-judge panel held then that EPA's interpretation of the Clean Air Act was "eminently reasonable" (Greenwire, Nov. 9, 2012).

The environmental groups that brought the challenge in Desert Citizens Against Pollution and Sierra Club v. EPA said EPA should be required to set standards for air pollutants other than mercury at gold mines and that the agency should have set standards for so-called fugitive emissions of hazardous pollutants, including mercury and hydrogen cyanide, that did not come from the mine's stacks.