The Ninth Circuit granted in part and denied in part a petition to review EPA's final rule approving California's SIP for meeting the air quality standard for ozone in the San Joaquin…

The Fifth Circuit upheld EPA's approval of Louisiana's SIP for controlling regional haze. Environmental groups challenged the approval of Louisiana's selection of low-sulfur coal…

The D.C. Circuit vacated EPA's 2018 update to the Cross-State Air Pollution Rule (CSAPR). States and environmental groups argued that EPA violated the CAA by failing to require upwind states…

The D.C. Circuit granted in part and denied in part a petition challenging EPA's update to the Cross-State Air Pollution Rule. Environmental groups and Delaware argued that EPA violated the…

The Ninth Circuit denied an environmental group's petition to review EPA's approval of a Montana SIP revision. The group argued that the approval was arbitrary and capricious because…

A district court dismissed on summary judgment environmental groups' lawsuit against a mining company for alleged SIP violations as it relates to NAAQS for coarse particular matter (PM10).…

The Ninth Circuit held that EPA did not act arbitrarily and capriciously when it disapproved in part Arizona's regional haze SIP and issued a replacement federal implementation plan (FIP) in…

The Third Circuit vacated and remanded EPA's approval of Pennsylvania's 2014 regional haze SIP. CAA §169A requires states to evaluate the impact that emissions from certain sources of…

The Seventh Circuit upheld EPA's approval of revisions to Illinois' SIP, thereby rejecting challenges raised by Indiana. Indiana argued that the relaxation of Illinois' vehicle…

The Ninth Circuit denied petitions for review challenging EPA's promulgation of 40 C.F.R. §52.245, a regulation that revised the scope of a previous EPA decision, after the Agency determined…