Federal Judge Blocks EPA Effort to Undo California Emissions Waivers Through Congress

A federal judge has blocked the Trump administration from treating four California Clean Air Act waivers as federal rules that could be quickly overturned by Congress, preserving California’s authority to enforce stricter emissions standards for vehicles and small engines while the lawsuit continues.

U.S. District Judge Beryl Howell in Washington issued a preliminary injunction Wednesday, September 2, ordering the Environmental Protection Agency to reverse steps it took in June to reclassify the California waivers as “rules” under the Congressional Review Act. The EPA had sent the waivers to Congress, opening the door for lawmakers to repeal them through the streamlined process provided by the law.

Howell found that California is likely to succeed in showing that the EPA acted unlawfully when it changed its longstanding treatment of the waivers.

“The EPA cannot say one thing to Congress while ignoring any consequence from reclassifying these waivers as rules,” Howell wrote. She ordered the agency to take the steps within its control to restore the situation that existed before its June 12 action.

The ruling gives California an important early victory in a larger fight with the Trump administration over the state’s unusual power to establish vehicle pollution standards that are tougher than federal requirements.

Federal law generally prevents states from creating their own emissions standards for new motor vehicles. California is the exception.

Because California began regulating vehicle pollution before the federal government established national standards, Section 209 of the Clean Air Act allows the state to seek waivers from the EPA, permitting it to enforce its own requirements. Other states may then choose to adopt certain California standards.

The EPA has granted California more than 75 such waivers over the past several decades under Republican and Democratic administrations, according to the California Attorney General’s Office.

The latest dispute centers on four waivers covering greenhouse gas and other emissions requirements for passenger vehicles and small off-road engines.

They include California’s greenhouse gas standards for new motor vehicles, the state’s Advanced Clean Cars I program, a later reinstatement of portions of that program and amendments covering small off-road engines used in equipment such as lawn mowers and leaf blowers.

The Trump administration has been trying to reduce California’s influence over national vehicle policy and expand consumer access to gasoline-powered vehicles.

On June 12, the EPA announced that it was sending the four waivers to Congress after determining that they qualified as rules under the Congressional Review Act. EPA Administrator Lee Zeldin said previous administrations had failed to submit the waivers to lawmakers and maintained that Congress was entitled to review them.

The Congressional Review Act gives Congress a faster route for overturning federal agency rules. A joint resolution of disapproval can move through the Senate under procedures that avoid the ordinary 60-vote threshold associated with overcoming a filibuster.

Classifying California’s waivers as rules therefore carried a major consequence. It potentially allowed the Republican-controlled Congress to eliminate them without requiring the EPA to go through the ordinary administrative process for reconsidering agency action.

California sued the EPA on June 22.

Attorney General Rob Bonta, Gov. Gavin Newsom and the California Air Resources Board argued that Clean Air Act waivers historically have been treated as agency orders granting California permission to enforce its own standards, rather than federal rules subject to congressional repeal under the Congressional Review Act.

California also accused the EPA of violating the Administrative Procedure Act by abruptly reversing that longstanding interpretation.

Howell found enough merit in those arguments to justify blocking the administration’s action while the case proceeds.

Her ruling focused in part on what she described as conflicting explanations from the government about what EPA had actually done.

EPA maintained that the waivers were rules and sent them to Congress on that basis. In court, the government also argued that the agency had merely transmitted information to Congress and had not taken an action affecting California’s legal rights.

Howell described the position as “Orwellian doublethink,” saying the government was effectively offering two explanations for the same action.

“Such gamesmanship may seem like a clever policy move, but undermines honest compliance with the law,” Howell wrote.

The preliminary injunction requires EPA to withdraw or correct its June reclassification and prevents the agency from giving that action legal effect while the litigation proceeds.

The decision does not permanently resolve whether Congress can use the Congressional Review Act against California emissions waivers. Nor does it settle the broader dispute over how far California may go in setting vehicle standards that affect automakers nationwide.

Another major fight over that question is already underway.

In 2025, the EPA sent three Biden-era California vehicle waivers to Congress under the same theory. Congress passed resolutions overturning them, and President Trump signed the measures.

One of those waivers allowed California to pursue its Advanced Clean Cars II program, which sought to require all new passenger vehicles sold in the state to meet zero-emission requirements beginning with the 2035 model year. Automakers, including General Motors and Toyota, urged Congress to overturn the California requirements.

California and other states separately challenged those congressional actions, and that litigation remains pending.

Wednesday’s case concerns a different group of waivers. The EPA attempted to send the four older approvals to Congress in June 2026, potentially exposing additional parts of California’s emissions program to repeal.

Lawmakers had been preparing to consider those waivers as soon as September before Howell intervened.

The dispute carries consequences beyond California.

Automakers generally design vehicles for national markets rather than separate state-by-state production systems. When California adopts stricter standards, and other states follow them, the requirements can influence which vehicles manufacturers produce and sell throughout large parts of the country.

The EPA argues that California’s standards can therefore shape national vehicle policy and raise costs for consumers outside the state. California maintains that Congress expressly gave it authority under the Clean Air Act to address its longstanding air pollution problems and permitted other states to follow its standards.

Howell’s ruling leaves the four challenged waivers in place while she considers whether EPA had legal authority to transform decades-old waiver decisions into rules eligible for congressional repeal.

The case could also determine whether future administrations can use the Congressional Review Act as an alternative way to attack California emissions programs long after the EPA originally approved them.

For now, the court has restored the system that existed before June: California’s four waivers remain effective, and the EPA may not rely on its reclassification to place them before Congress for expedited repeal while the lawsuit continues.