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purposes of addressing life-cycle greenhouse gas (GHG) emissions associated with crop-based biofuels—it reused an outdated study instead of newer data from the Agency’s literature review of the most reliable post-2010 findings; and that FWS failed to adequately explain how its conclusion that the rule would have “no effect” on endangered species or critical habitats accorded with the legal framework set forth in its Consultation Handbook and ESA implementing regulations. The court found EPA's analysis failed to adequately explain why the Agency used a nearly 15-year-old study to estimate the effect of crop-based fuel production on GHG emissions rather than the literature review it had conducted for expressly that purpose and used to estimate effects of other types of renewable fuels. It further found FWS failed to adequately explain its concurrence with EPA as to effects on endangered species. Petroleum refiners, a renewable fuel producer, and a trade group representing biodiesel stakeholders also challenged the rule, but the court denied the refiners' and fuel producer's petition and dismissed the trade group's petition for untimeliness and lack of standing. It remanded without vacatur to EPA and FWS for further consideration and explanation.

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 purportedly showed the two counties in attainment, that the Agency unlawfully treated similarly situated counties in other states differently from the two counties, and that it misconceived the law in issuing the designation and denying petitions for reconsideration because EPA erroneously believed it did not have authority to delay classification until the state gathered monitoring data. The court found EPA's failure to reconcile inconsistencies between predictions of the model on which it based its designation and monitoring data that showed actual sulfur dioxide concentrations below NAAQS created an unexplained inconsistency, and that it could not "excuse the Agency's reliance upon a methodology that generate[d] apparently arbitrary results." It remanded for further proceedings.

The Third Circuit affirmed a district court order remanding to state court a lawsuit concerning a chemical company's design, manufacture, marketing, and sale of 1,4-dioxane. The state of New Jersey sued the company in state court, arguing its products substantially harmed the environment. The company removed the suit to federal court under the federal officer removal statute, asserting that it acted under the U.S. government and military in designing and producing 1,4-dioxane inhibited 1,1,1-trichloroethane (TCA). The district court found the company was not acting under the government because it produced and sold 1,4-dioxane inhibited TCA "independently and before the implementation of the federal regulations on which it relies"; it ordered the suit to be remanded to state court. The appellate court found the company did not satisfy the "acting under" test because the government never guided or controlled the company's production of inhibited TCA, and nothing required the company to create and sell it to the government. It affirmed remand to state court.

The Fifth Circuit dismissed environmental groups' petition to review an EPA rule granting Louisiana primary enforcement authority over Class VI underground carbon sequestration wells. The groups petitioned under the SDWA's review provision, and the state and its Department of Energy and Natural Resources intervened. The court found the groups could not trace any alleged injuries to EPA's grant of primacy to the state because the same wells could be built with or without EPA granting primacy, and thus failed to demonstrate standing. It dismissed the petition.

The Fifth Circuit granted industry groups' challenge to EPA's 2024 rule that revised the equation for calculating vehicle fuel economy for purposes of the Corporate Average Fuel Economy (CAFE) standards and required manufacturers to certify fuel economy using E10 test fuel, containing 10% ethanol, beginning in model year 2027, but allowed carryovers of results for E0 test fuel, containing no ethanol, for certain model year 2027-2029 vehicles. The groups argued the rule set one part of the equation—a sensitivity factor that measures how much a fuel's economy changes in response to an alteration on the test fuel's energy content—arbitrarily low, artificially increasing the stringency of the CAFE standards and decreasing demand for their gasoline products. The court found EPA violated the APA by ignoring comments during the rulemaking process that flagged fundamental flaws in its determination of the sensitivity factor, including that the Agency had tested too few vehicles, had used unrepresentative vehicle technologies, and had arbitrarily analyzed data from the test program that it had conducted itself instead of using manufacturing certification data as previously planned. It granted the petition and vacated the rule to the extent that it set a sensitivity factor of 0.81 and implemented that factor by shifting the test fuels from E0 to E10 for fuel economy compliance.

The Ninth Circuit reversed a district court's dismissal of a challenge to BLM's authorization of construction on a transmission line through the San Pedro Valley. Native American tribes and environmental groups argued BLM violated the National Historic Preservation Act by issuing limited notices to proceed before satisfying its obligations under a programmatic agreement (PA) governing implementation of the project. BLM and the construction company moved to dismiss for failure to state a claim, and the district court granted the motion. The appellate court found plaintiffs plausibly alleged that BLM violated the PA by failing to consult with them on a historic property treatment plan that would evaluate whether the valley should be designated as a historic property and by authorizing construction before properly identifying all historic properties affected by the project and ensuring that any adverse effects would be avoided, minimized, or mitigated. It reversed the district court's dismissal and remanded.

The Ninth Circuit affirmed in part and reversed in part summary judgment for BLM in challenges to approval of an oil and gas project in the northern Arctic. Environmental groups argued BLM failed to consider a reasonable range of alternatives as required under NEPA, its mandate to protect surface resources under the Naval Petroleum Reserves Production Act (Reserves Act), and its obligation to reduce impacts to subsistence users under the Alaska National Interest Lands Conservation Act (ANILCA), and violated the ESA by failing to consult with FWS and NMFS on how the project's carbon emissions might affect protected species and critical habitat. A district court granted summary judgment for BLM, concluding its alternatives analysis satisfied NEPA, the Reserves Act, and ANILCA, and that the groups had failed to show the Bureau violated ESA §7 by not addressing how the emissions could affect polar bears or ice seals. The appellate court found BLM did not abuse its discretion in basing its alternatives analysis on the "full field development standard" to avoid the risks of piecemeal development, but that it failed to provide a reasoned explanation for its final chosen alternative, which did not comply with that standard. It further found that because nothing in the standard precluded BLM from implementing protective conditions on exploration, it did not itself violate the Preserves Act, and that the standard was not contrary to §810 of ANILCA. As to the ESA claim, the court found each agency satisfied its §7 obligations by providing detailed scientific explanations for its conclusions that the effects of the emissions on listed species were not sufficiently linked to merit further evaluation. It remanded the NEPA claim without vacatur.

A district court granted in part and denied in part an aerospace company's motion to dismiss a lawsuit alleging that it failed to address the release of hazardous materials on an 18-acre property in the town of Oyster Bay between 1949 and 1962 and that has since become a community park. The town brought claims under RCRA and TSCA, as well as public nuisance and promissory estoppel claims under New York common law. The company moved to dismiss. The town moved for a preliminary injunction, arguing the company had since discovered concrete-encased metal barrels containing hazardous materials it had buried beneath the park between 1949 and 1962, and seeking an injunction ordering the company to proceed with digging open test pits per an investigation plan approved by the New York State Department of Environmental Conservation, but to dispose of all excavated soil off-site. The court denied the company's motion to dismiss the RCRA §7002(a)(1)(B) claim, because the town plausibly alleged the hazardous materials deposited at the park constituted an "imminent and substantial endangerment," or to dismiss its public nuisance claim, but dismissed the other claims. It denied the town's motion for preliminary injunction, finding it failed to show a clear likelihood of success on its claim that reburying soil back in the park on a temporary basis pending further remediation would violate RCRA §7002(a)(1)(B), that the temporary burial would result in irreparable harm, and that its proposed alternative—off-site removal of all soil from test pits—would serve the public interest or was favored by the balance of equities.

A district court reversed its prior dismissal of a challenge to four BLM leasing decisions concerning federal land in Utah. An environmental group had argued BLM violated NEPA and the ESA by failing to fully analyze the environmental, social, direct, indirect, and cumulative impacts of the lessees' planned drilling on emissions, water resources, and animal species; failing to adhere to congressionally required notice-and-comment procedure; failing to identify a reasonable range of alternatives; and failing to consult with FWS. An oil and gas company and the state of Utah intervened and moved to dismiss for lack of subject matter jurisdiction. The court granted the motion, holding the claims were not ripe due to a lack of final agency action. The group subsequently moved to alter judgment, arguing their claims were ripe because nearly half of the challenged leases were active and because BLM had approved certain applications for permits on January 30, 2025. The court found the group had standing because the leasing decisions posed imminent, definite harm to the group's members and employees. It granted the motion to reconsider and denied defendants' motion to dismiss.

The Ninth Circuit affirmed in part and reversed in part summary judgment for BLM in challenges to approval of an oil and gas project in the northern Arctic. Environmental groups argued BLM failed to consider a reasonable range of alternatives as required under NEPA, its mandate to protect surface resources under the Naval Petroleum Reserves Production Act (Reserves Act), and its obligation to reduce impacts to subsistence users under the Alaska National Interest Lands Conservation Act (ANILCA), and violated the ESA by failing to consult with FWS and NMFS on how the project's carbon emissions might affect protected species and critical habitat. A district court granted summary judgment for BLM, concluding its alternatives analysis satisfied NEPA, the Reserves Act, and ANILCA, and that the groups had failed to show the Bureau violated ESA §7 by not addressing how the emissions could affect polar bears or ice seals. The appellate court found BLM did not abuse its discretion in basing its alternatives analysis on the "full field development standard" to avoid the risks of piecemeal development, but that it failed to provide a reasoned explanation for its final chosen alternative, which did not comply with that standard. It further found that because nothing in the standard precluded BLM from implementing protective conditions on exploration, it did not itself violate the Preserves Act, and that the standard was not contrary to §810 of ANILCA. As to the ESA claim, the court found each agency satisfied its §7 obligations by providing detailed scientific explanations for its conclusions that the effects of the emissions on listed species were not sufficiently linked to merit further evaluation. It remanded the NEPA claim without vacatur.