The Fifth Circuit rejected an environmental group's challenge to the Louisiana Department of Environmental Quality's (LDEQ's) decision to issue preconstruction permits for a…

The D.C. Circuit upheld EPA's 2022 decision to reinstate a prior waiver of federal preemption of two California regulations concerning automobile emissions under the CAA. States and fossil…

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 Fifth Circuit, 2-1, denied petitions to review EPA's 2016 designation of two counties in Texas as nonattainment for the 2010 sulfur dioxide NAAQS. The state of Texas and the owner of a…

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 Fifth Circuit, 2-1, granted six small refineries' petitions to review an EPA decision denying their requested exemptions from obligations under the CAA Renewable Fuel Standard (RFS)…

The Fifth Circuit vacated the Texas Commission on Environmental Quality's (TCEQ's) order granting a PSD permit for a new liquefied natural gas (LNG) facility in Texas. An environmental…

The D.C. Circuit denied the state of Utah's motion to stay EPA's 2023 "good neighbor" rule, which aims to ensure that 23 states meet the CAA's good neighbor requirements…

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…

A district court granted summary judgment for several bus companies in a CAA citizen suit alleging that the companies excessively idled their buses in violation of Massachusetts and Connecticut…