A federal judge has temporarily halted the Environmental Protection Agency (EPA) from challenging California’s authority to set stricter vehicle pollution standards than federal requirements.
The legal conflict arose from a decision by EPA Administrator Lee Zeldin in June, declaring that four of California’s Clean Air Act preemption waivers were “rules” needing congressional approval under the Congressional Review Act. These waivers allow California to implement its own vehicle emissions standards, impacting smog reduction efforts nationwide. See more on the countrywide impact.
The EPA has granted over 100 waivers to California since the Clean Air Act was enacted more than 60 years ago, none previously considered as rules. Zeldin asserts prior administrations erred by not submitting waivers for congressional review.
California Attorney General Rob Bonta, Governor Gavin Newsom, and the California Air Resources Board filed a lawsuit in the U.S. District Court for the District of Columbia in June to challenge the reclassification of these waivers.
Following the lawsuit, the EPA reclassified two additional waivers concerning boat emissions standards.
Judge Beryl A. Howell granted California’s request for a preliminary injunction, preventing further EPA action until the lawsuit’s resolution. Howell ordered the agency to return to the pre-reclassification status quo from June.
“EPA’s reclassification of prior waivers as ‘rules’ undermines compliance with the law,” Howell stated in her decision.
As the only state with pre-existing motor vehicle emissions standards before the 1963 Clean Air Act, California can seek a waiver of federal preemption, allowing it to impose its standards.
This unique authority enables California to apply for and receive preemption waivers from the EPA, which other states can adopt but not alter.
Bonta praised the injunction as a victory against the previous administration’s efforts, stating that federal standards should be a baseline, not a ceiling, for protecting the future.
“Such gamesmanship may seem like a clever policy move, but undermines honest compliance with the law, which is what Americans should expect from executive branch agencies.”
— Judge Beryl A. Howell
Both Democratic and Republican administrations have previously upheld California’s authority to set emissions standards. However, this administration aims to reverse this trend, according to Bonta.
The EPA indicated it is “considering immediate appeal options.”
Environmental advocates, who viewed the EPA waiver reclassification as an attack on clean air protections, welcomed the ruling.
“Everyone can breathe easier knowing California’s strong clean car and truck standards are prevailing,” said David Pettit, a senior attorney at the Center for Biological Diversity’s Climate Law Institute.
This lawsuit is California’s second against the EPA since President Donald Trump returned to office, challenging the reclassification of waivers as rules needing congressional approval.
During Trump’s second term, his administration targeted California’s authority over state standards, including an executive order to eliminate state emissions waivers restricting gasoline-powered vehicle sales.
In February 2025, the EPA reclassified three California waivers as rules needing approval, including one requiring all passenger vehicles sold in the state to be zero-emission by 2035. The Republican-controlled Congress passed disapproval resolutions for all three.
California sued, arguing the resolutions are unlawful. This case is being heard in the U.S. District Court for the Northern District of California.
This story was updated on September 3, 2026, to include comment from the EPA.
Original Story at insideclimatenews.org