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 endanger the public health or welfare under CAA §231(a)(2)(A). A finding that emissions cause or contribute to...

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. The preconstruction projection determines whether the project constitutes a “major modification” and t...

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 unauthorized by the CAA because EPA failed to make the statutorily required error determination. Neither the text of the fin...