In a per curiam decision, the D.C. Circuit, 2-1, granted environmental groups' challenge to an EPA rule implementing Renewable Fuel Standards (RFS) Program standards for 2023-2025. The groups argued EPA failed to adequately explain why—for purposes of addressing life-cycle greenhouse gas (GHG) emi...

The U.S. Supreme Court, 7-2, held that several fuel producers had standing in a lawsuit challenging EPA's approval of California regulations requiring automakers to manufacture more electric vehicles and fewer gasoline-powered vehicles in an effort to decrease emissions from liquid fuels. The produc...

The U.S. Supreme Court, 7-2, held that EPA's 2022 denials of six small refinery exemption petitions were locally or regionally applicable actions that fell within the "nationwide scope or effect" exception under the CAA, requiring venue in the D.C. Circuit. The small refineries challenged the denial...

he U.S. Supreme Court, 8-0, held that EPA's disapprovals of Oklahoma's and Utah's SIPs were locally or regionally applicable actions reviewable in a regional circuit court. The two states petitioned the Tenth Circuit to review the disapprovals, which were two of 21 SIPs EPA disapproved in 2023 for f...

A district court denied summary judgment for a company that owns and manages Iowa farmland in a lawsuit concerning a federal wetland conservation law known as Swampbuster. The company challenged the program, which disqualifies one from receiving USDA farm benefits if they convert certified wetl...

The Fifth Circuit agreed to rehear a petition for review that it previously denied concerning EPA's designation of two counties in Texas as nonattainment for the 2010 sulfur dioxide NAAQS. The state of Texas and a power plant operator argued EPA violated the CAA by ignoring monitoring data that purp...

The Tenth Circuit granted in part and denied in part an environmental group's petition to review EPA approval of Colorado's 2019 SIP revisions. The group argued the revision to the permit requirement for new emission sources prevented regulators from blocking construction when a new source woul...

The Fifth Circuit granted in part and denied in part states' challenges to EPA's disapprovals of SIPs developed in response to the Agency's 2015 decision calling for SIPs to achieve a new ozone NAAQS. Texas, Louisiana, and Mississippi argued EPA's disapprovals of their SIPs were arbitrary and capric...

Tribal groups argued NMFS violated NEPA in adopting the harvest specifications because they relied on outdated EISs despite dramatic changes to the ecosystem that necessitated an updated environmental analysis. The court found the specifications were not arbitrary and capricious because NMFS conclud...

The Tenth Circuit denied environmental groups' petition to review an EPA rule that partially approved Colorado's SIP to reduce ozone pollution. The groups sought vacatur of the approval, arguing the Agency violated the CAA by approving the reasonable further progress and motor vehicle emissions budg...