This week, Congress disapproved the U.S. Environmental Protection Agency waivers given to California for that state’s recent zero- and low- emission regulations. Three joint resolutions —H.J.Res. 87, 88, and 89 — used the Congressional Review Act (CRA) to revoke the previous federal authorization for California to implement the Advanced Clean Cars II (ACC II), Advanced Clean Trucks (ACT), and Heavy-Duty Low NOx Omnibus (Omnibus) regulations. The resolutions have passed both the Senate and House and are expected to be signed into law by the White House. If enacted, these resolutions would prevent California, and any states that opt into California’s rules, from implementing these zero-emission requirements.
On May 21, the Senate voted 51 to 44 to overturn the EPA waiver granted to California to enforce ACC II, which mandates all new passenger cars, trucks, and SUVs to be zero emission by 2035. On May 22, the Senate voted to overturn the EPA waivers granted to California to enforce the ACT and Omnibus rules, which mandate zero emission medium- and heavy-duty truck sales through 2035 and set stricter tailpipe emissions standards for medium- and heavy-duty trucks. The ACT waiver also includes the Zero Emission Airport Shuttle regulation and Zero Emissions Powertrain (ZEP) certification.
In response, California’s Governor Gavin Newsom and Attorney General Rob Bonta announced today that the state will file a lawsuit, focusing on the role of the CRA to overturn the waivers. While the CRA can enable the repeal of recently approved regulations with a simple majority, procedural questions have been raised the applicability of this process for waivers.
As Governor Newsom noted in a press release, U.S. Congress is “using the Congressional Review Act (CRA) to attempt to revoke California’s Clean Air Act waivers, which authorize California’s clean cars and trucks program. This defies decades of precedent of these waivers not being subject to the CRA and contradicts the non-partisan Government Accountability Office and Senate Parliamentarian, who both ruled that the CRA’s short-circuited process does not apply to the waivers.” The chair of the California Air Resources Board, Liane Randolph, also released a statement underscoring California’s intent to “pursue every available remedy to challenge these actions.”
These congressional actions and California’s response follow months of uncertainty over implementation and market readiness in states across the country. Aside from these federal legislative efforts, Maryland, Massachusetts, Oregon, and Vermont recently decided to delay the implementation of their own adoption of California’s Advanced Clean Trucks rule.
On May 13, Vermont Governor Phil Scott issued an executive order postponing the state’s compliance with the ACT rule until at least 2027. Governor Scott cited insufficient charging infrastructure and technological limitations in heavy-duty electric vehicles as primary reasons for the delay. The executive order directs state enforcement agencies not to issue fines or penalties for noncompliance during this period. Additionally, the order postpones Vermont’s compliance with another California rule that creates zero-emission mandates for heavy-duty trucks.
Similarly, the Oregon Department of Environmental Quality (DEQ) announced a pause in the enforcement of its Advanced Clean Trucks rule a few days later, effective immediately, for the 2025 and 2026 model years. DEQ Director Leah Feldon acknowledged the challenges faced by the trucking industry in meeting the new requirements, stating that the pause is intended to provide temporary relief while maintaining progress toward Oregon’s environmental goals.
