The D.C. Circuit vacated DOE's 2020 rule establishing more stringent energy efficiency standards for commercial packaged boilers, and its 2022 supplemental document responding to the court's previous remand order that it address comments raised during the rulemaking process. Industry groups argued D...

The U.S. Supreme Court held, 5-4, that an 1868 peace treaty between the Navajo Nation and the United States establishing the Navajo Reservation reserved necessary water to accomplish the purpose of the reservation, but did not require the U.S. government to take affirmative steps to secure water for...

The Ninth Circuit, 2-1, denied a municipal irrigation district's request to compel a district court to remand to state court its motion for preliminary injunction in a suit concerning water allocation in the Klamath Basin. The district initially sought to stop the Bureau of Reclamation from releasin...

A district court granted in part and denied in part an environmental group's motion for summary judgment in a CWA citizen suit concerning the Forest Service's discharge of aerially deployed fire retardant into navigable waters of the United States without an NPDES permit. The group argued the Servic...

The U.S. Supreme Court held that the CWA extends to only those "wetlands with a continuous surface connection to bodies that are 'waters of the United States' in their own right," such that they are indistinguishable from those waters, in a challenge to an EPA compliance order stating that landowner...

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...

The Ninth Circuit reversed a district court's dismissal of an industry group's challenge to the city of Berkeley's natural gas hookup ban. The group argued the federal Energy Policy and Conservation Act (EPCA) preempted the ban, which enacted a building code prohibiting installation of natural gas p...

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...