The Sixth Circuit granted the Commonwealth of Kentucky's and business groups' motions to preliminarily enjoin EPA's and the Army Corps of Engineers' 2023 rule revising the definition of "waters of the United States" under the CWA. A district court had denied the motions, concluding plaintiffs lacked...

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In an unpublished order, the Fifth Circuit, 2-1, stayed EPA's disapproval of SIPs submitted by Texas and Louisiana following the Agency's 2015 revision to the ozone NAAQS.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 Fourth Circuit, 2-1, vacated a district court ruling in a lawsuit concerning the Army Corps of Engineers' plan for maintaining a dam on the Savannah River. The state of South Carolina argued the Corps' plan violated the Water Infrastructure Improvements for the Nation (WIIN) Act because it would...

A district court granted 24 states' motion to preliminarily enjoin EPA's and the Army Corps of Engineers' 2023 rule revising the definition of "waters of the United States" under the CWA. The states argued the rule violated the APA, the Commerce Clause, the Tenth Amendment, the Due Process Clause, a...

A district court granted Texas' and Idaho's motion to preliminarily enjoin EPA's and the Army Corps of Engineers' 2023 rule revising the definition of "waters of the United States" under the CWA. The states sought to enjoin the rule within their borders, arguing it was unconstitutional and violated ...

A district court denied for lack of jurisdiction the Commonwealth of Kentucky's and business groups' motions to preliminarily enjoin EPA's and the Army Corps of Engineers' 2023 rule revising the definition of "waters of the United States" under the CWA. The court found that plaintiffs failed to show...

The Fourth Circuit vacated the West Virginia Department of Environmental Protection's CWA §401 certification for a proposed pipeline that would transport natural gas from West Virginia to southern Virginia. Landowners and environmental groups petitioned for review of the certification, arguing the ...

The Fourth Circuit denied a petition to review the Virginia Department of Environmental Quality's (DEQ's) and the State Water Control Board's approval of a state water permit for a proposed pipeline that would transport natural gas from West Virginia to southern Virginia. Environmental groups argued...

A district court granted in part an environmental group's motion for summary judgment in a challenge to NMFS' 2021 permit authorizing the incidental taking of ESA-listed humpback whales in a sablefish fishery off the Pacific coast. The group argued NMFS violated the Marine Mammal Protection Act (MMP...