State implementation plans (SIPs)

The D.C. Circuit, 2-1, granted in part and denied in part petitions to review EPA's SIP call for 35 states and the District of Columbia. A group of about half these states as well as…

The Fourth Circuit, 2-1, granted West Virginia's motion to stay EPA's disapproval of its SIP addressing "good neighbor" obligations under the revised 2015 air quality standards…

The Tenth Circuit, 2-1, granted in part an environmental group's challenge to EPA's approval of a Colorado SIP revision certifying that the state's existing, EPA-approved…

The Tenth Circuit affirmed in part and vacated in part EPA's partial approval and partial disapproval of Wyoming's SIP addressing emissions at coal-fired power plants to reduce regional…

The Tenth Circuit denied environmental groups' petition to review approval of Utah's July 2019 revised SIP addressing regional haze. The groups argued EPA abused its discretion by…

The Third Circuit denied an environmental group's petitions to review EPA's approval of certain air pollution control technology use at industrial facilities in Pennsylvania. The group…

In an unpublished order, the Fifth Circuit, 2-1, stayed EPA's disapproval of SIPs submitted by Texas and Louisiana following the Agency's 2015 revision to the ozone NAAQS. The states…

The Sixth Circuit granted a petition to review EPA's removal of an air nuisance rule from Ohio's SIP. Environmental groups and individuals argued that EPA violated the CAA and APA in…

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…

A district court granted states' motion for summary judgment in a lawsuit concerning EPA's duty to limit air pollution drifting from upwind states into northeastern states. Connecticut,…