On August 31, 2026, the National Highway Traffic Safety Administration (NHTSA) published an interpretive rule concluding that it lacks statutory authority to establish standalone fuel economy standards for engines used in certain commercial medium-duty and heavy-duty (MDHD) on-highway vehicles. The
Environmental and Energy Brief
Environmental and Energy Brief, published by Sidley Austin LLP, covers legal developments and regulatory changes affecting environmental law, energy policy, and related compliance issues. The blog addresses topics such as federal and state regulatory proposals, enforcement actions, and litigation trends involving agencies like the EPA, Department of Transportation, and FERC. It also discusses impacts on sectors including automotive fuel economy standards, endangered species protections, water resource regulation, and energy infrastructure. The blog provides analysis of rulemakings, court decisions, and administrative actions that influence environmental and energy law practice and policy.
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EPA and the Army Corps Seek Comment on Another WOTUS Alternative for Implementing Sackett v. EPA
On September 4, 2026, the U.S. Environmental Protection Agency (EPA) and the Department of the Army, U.S. Army Corps of Engineers (together, the agencies), announced a supplemental notice of proposed rulemaking (SNPRM) that requests additional public input on rules the…
Federal Court Strikes Down New York’s Climate Change Superfund Act
On August 31, 2026, the U.S. District Court for the Northern District of New York struck down New York’s Climate Change Superfund Act (the Act). As we reported when the Act was signed into law in 2024, the Act established…
SB 253/SB 261 Update: What CARB’s 15-Day Modifications Mean for Business Compliance Plans
U.S.-based entities with at least $1 billion in global annual revenue that do business in California should revisit their 2026 SB 253 compliance plans following the release, by the California Air Resources Board (CARB), of 15-day modifications to its proposed…
NHTSA Announces a Host of Actions on Autonomous Vehicles
On July 30, on the last day of the SAE International Automated Transportation Symposium, the National Highway Traffic Safety Administration (NHTSA) released several rulemakings and announcements focused on automated driving systems (ADS). These announcements further NHTSA’s efforts to, in…
Court Order Blocks Enforcement of California’s SB 343 Recycling Law and Could Impact State’s Extended Producer Responsibility Program
Companies that manufacture products bearing recyclability labels have received temporary relief from impending compliance obligations. On July 14, 2026, the U.S. District Court for the Southern District of California issued a preliminary injunction preventing California, “the State,” from enforcing SB…
Federal Agencies Rescind Endangered Species Act Definition of “Harm,” Narrowing the Scope of Prohibited Activity Affecting Wildlife
The U.S. Fish and Wildlife Service and National Marine Fisheries Service have issued a final rule rescinding the regulatory definition of “harm” under the Endangered Species Act (ESA). The change is significant because the longstanding definition provided that prohibited “harm”…
The Department of Transportation’s 2026 Regulatory Agenda: Acceleration of Autonomous Vehicle Rulemaking and Future Action on Fuel Economy
On July 7, 2026, the Department of Transportation released its 2026 unified rulemaking agenda. Many of the items on it relate to autonomous driving systems. They signal that the Trump Administration is accelerating its efforts to promote the development…
SB 253 Update: CARB Delays Reporting Deadline to November 2026 and Proposes to Clarify Requirements
Companies preparing to comply with California’s Senate Bill (SB) 253 and submit their first required disclosures in August 2026 have received an update this week from the California Air Resources Board (CARB) that will delay reporting deadlines. On June 24…
NHTSA Proposes Amending Federal Brake Standards for Autonomous Vehicles
On June 26, the National Highway Traffic Safety Administration published another proposed rulemaking designed to promote the deployment of autonomous vehicles on public roads. The proposal would amend Federal Motor Vehicle Safety Standard (FMVSS) No. 135, “Light vehicle brake systems,”…