The D.C. Circuit vacated EPA's withdrawal of its determination to regulate perchlorate in drinking water. An environmental group argued EPA lacked the authority to withdraw the determination under the SDWA, and that even if it did have such authority, it acted arbitrarily and capriciously in doing s...

In an unpublished order, the Fifth Circuit, 2-1, stayed EPA's disapproval of SIPs submitted by Texas and Louisiana following the Agency's 2015 revision to the ozone NAAQS.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 moved for a stay pending review of EPA's disapproval. The court found a stay was appropriate because the states made ...

The D.C Circuit denied an industry group's challenge to EPA's 2021 rule requiring power plants in several upwind states to reduce nitrogen oxide emissions. The group argued the rule was arbitrary and capricious, and that EPA failed to conduct a legally and technically appropriate assessment as requi...

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 removing the rule. EPA moved to remand without vacatur to review its removal of the rule. The court found that vacatu...

The Fifth Circuit granted small refiners' motion to stay certain compliance obligations under the CAA pending appeal of EPA's decision denying their requested hardship exemptions from the Act's Renewable Fuel Standard obligations. The refiners argued EPA's late 2021 interpretation of CAA provisions ...