The D.C. Circuit granted in part and denied in part petitions concerning EPA's NESHAPs for industrial boilers. The first challenge raised by environmental groups concerned regulations that indirectly control a group of organic pollutants by limiting carbon monoxide emissions as a proxy for the targe...

The D.C. Circuit held that EPA unlawfully revoked the 1997 ozone NAAQS when it implemented the 2008 standard. In 2008, EPA set the ozone NAAQS at 75 parts per billion (ppb). In 2015, when implementing the standard, the Agency eliminated the 1997 standard of 84 ppb on the grounds that it was impossib...