A district court granted EPA's motion to dismiss a TSCA citizen suit brought by environmental groups concerning fluorination. The groups sought to compel EPA to prohibit the company's fluorination practices, which produced per- and polyfluoroalkyl substances (PFAS), a class of carcinogenic chemicals, that had been found in plastic packaging manufactured by the company. After the groups filed suit, EPA initiated a rulemaking to address the production of PFAS. EPA moved to dismiss, arguing its rulemaking mooted the groups' primary request for relief, and that the court lacked jurisdiction to adjudicate their secondary demand that the Agency seek injunctive relief until the rule is effective. The court found EPA had fulfilled any nondiscretionary duties under TSCA, and granted its motion to dismiss.

A district court granted an electric transmission developer's motion for preliminary injunction against Indiana's 2023 law that granted incumbent transmission owners a right of first refusal to build transmission projects in their service areas. The developer argued the law blocked it from bidding on several forthcoming projects, and sought to enjoin its enforcement because it violated the dormant Commerce Clause. The court found the law facially discriminated against out-of-state economic interests and could not survive strict scrutiny. It issued a preliminary injunction prohibiting enforcement of the right of first refusal.

The Fifth Circuit granted EPA's motion to vacate its disapprovals of portions of regional haze SIPs submitted by Texas and Oklahoma and the issuance of federal implementation plans (FIPs) establishing a long-term strategy and/or reasonable progress goals for the states. EPA argued that because key documents in the administrative record were no longer in the Agency's possession, the record did not contain statutorily required information necessary for judicial review of the final rule issuing the FIPs. The court found that absent evidence the Agency admitted was key in adjudicating the rule, the rule was arbitrary and capricious and must be vacated. It granted EPA's motion and vacated the final rule.

The Fifth Circuit reversed in part a district court's dismissal of a lawsuit brought by property owners against the city of Dallas and the Army Corps of Engineers concerning an ongoing floodway extension project. The owners argued the Corps' failure to prepare a supplemental EIS to account for new information, such as flood risk updates related to climate change and changes to engineering guidance following Hurricane Katrina, violated NEPA and the CWA. The district court determined the owners' claims were not ripe for adjudication and dismissed the suit for lack of jurisdiction. The appellate court found the claims were ripe because the Corps' purported failure to comply with its NEPA obligations presented a present controversy that required no further factual development, and that the owners properly alleged standing for their claims against the Corps. It reversed and remanded the district court's dismissal with respect to the Corps, and affirmed with respect to Dallas.

A district court denied conservation groups' petition to review the Forest Service's approval of a revised management plan for the Rio Grande National Forest. The groups argued the Service's approval violated the National Forest Management Act and the 2012 Planning Rule by not including species-specific plan components to contribute to recovery of the Uncompahgre fritillary butterfly (UFB), and violated NEPA by failing to take a "hard look" at the plan's effects on the UFB and the Canada lynx and by failing to analyze a reasonable range of alternatives. The court found the groups failed to show it was unreasonable for the Service to conclude that the plan's components sufficiently facilitated recovery of the UFB and that additional fine-filter components were not necessary. It further found the Service considered and applied what it considered to be the best available science in approving the revised plan, and that the groups did not demonstrate the Service failed to consider a reasonable range of alternatives when it discussed and rejected the two proposed special interest areas. It denied the groups' petition.

A district court granted in part environmental groups' motion for summary judgment in a CAA citizen suit concerning EPA's duty to update emissions standards for hazardous waste combustors. The groups sought declaratory judgment stating that EPA failed to comply with its obligations and injunctive relief mandating that the Agency review and revise the standards or determine that such revision is not necessary by a certain date. Both parties agreed that over eight years had passed since the Agency promulgated standards, and that it had not completed the required risk and technology review (RTR), but the groups argued EPA had failed to demonstrate it was "impossible" to complete the rulemaking before its proposed date of August 14, 2026. The court found EPA did not establish that it needed that long to finish the rulemaking, and ordered it to complete the RTR by December 31, 2025.

The Ninth Circuit granted in part environmental groups' petition to review EPA's decision refusing to revise technology-based effluent limits, guidelines, and standards (ELGs) for certain industries previously promulgated under the CWA. The groups challenged EPA's decision refusing to revise ELGs for seven specific source categories that they argued were substantially out of date. The court agreed with EPA that it was not required to revise every outdated ELG, but ruled its refusal as to the categories at issue failed to properly consider advances in pollution control technology, failed to properly consider pretreatment standards and guidelines applicable to indirect dischargers, and failed to properly consider information relating to pollutants not currently covered by the applicable ELGs. It remanded to EPA to reconsider its decision or provide a fuller explanation.

The Montana Supreme Court affirmed a trial court ruling that declared the Montana Environmental Policy Act (MEPA) violated youths' state constitutional right to a "clean and healthful environment." The youths argued a provision of MEPA that precluded analysis of greenhouse gas emissions in EAs and EISs was unconstitutional, and that their express right under the Montana Constitution to a clean and healthful environment had been violated. The lower court found the fundamental constitutional right included climate as part of the environmental life support system, that the youths had standing, and that the MEPA limitation violated the constitution's right to a clean and healthful environment, and it permanently enjoined its enforcement. The high court found the youths had standing to challenge the injury to their right to a clean and healthful environment, that such right was violated by the MEPA limitation, and that the limitation was unconstitutional. It affirmed the lower court's order enjoining the state from enforcing the MEPA limitation.