The Sixth Circuit held that the CAA does not categorically prevent EPA from challenging preconstruction projections of whether and to what extent emissions will increase following construction.…

A district court held that EPA has no mandatory or nondiscretionary duty to make a determination as to whether lead emissions from general aviation aircraft engines using aviation gasoline…

The Eleventh Circuit vacated EPA's 2011 disapproval of Alabama SIP provisions on opacity, thereby reinstating EPA's 2008 approval of opacity limits. EPA's 2011 disapproval was…

The D.C. Circuit vacated EPA's 2012 projection of cellulosic biofuel production under the renewable fuel standard (RFS) program. As part of the RFS program, CAA §211(o)(7)(D)(i) requires EPA…

The D.C. Circuit dismissed a road building association's lawsuit challenging EPA regulations for nonroad engines and vehicles. The regulations pertain to CAA §209(e), which preempts certain…

The D.C. Circuit ordered EPA to repromulgate two final rules it issued under the CAA concerning the implementation of the NAAQS for fine particulate matter (PM). Environmental groups challenged…

The Ninth Circuit denied an environmental group's petition challenging EPA's decision to grant two air permits authorizing exploratory drilling operations in the Arctic Ocean by a…

The D.C. Circuit denied a petition for rehearing of an earlier decision in which it upheld four EPA rulemakings governing greenhouse gases. EPA issued the rules following the U.S. Supreme Court…

The D.C. Circuit upheld an EPA rule that added the gold mine ore processing and production area source category to the list of source categories to be regulated under CAA §112(c)(6). CAA §112(c)(6…

The D.C. Circuit held that EPA's determination that it completed sufficient standards to meet CAA §112(c)(6)'s 90% requirement for hazardous air pollutants is a legislative rulemaking…