Ecology proposes fallback plan to protect progress on clean vehicles in case of federal rollbacks

The Washington Department of Ecology has proposed a contingency plan for the state's vehicle emissions standards, which have been challenged at the federal level. The plan is being considered through Ecology's rulemaking process and would ensure that Washington continues decarbonizing transportation, lowering costs for drivers, and protecting communities from harmful air pollution, regardless of federal actions.

Vehicle emissions standards are a critical tool for addressing climate change and improving air quality. Washington's standards expand clean car options for consumers and ensure that new gas- and diesel-powered vehicles pollute less.

Gas- and diesel-powered vehicles are the state's biggest source of greenhouse gas emissions, and a leading source of toxic air pollutants, including those that cause cancer. People living near major transportation corridors are especially vulnerable to these pollutants. As of 2019, nearly one million Washingtonians lived within a quarter mile of heavy traffic roadways. Since then, the state's population has increased by over 500,000 people, with the majority of that growth occurring in major metro areas.

In 2025, Congress attempted to strip Washington and other states of their longstanding authority to protect residents from harmful vehicle pollution by opting for emissions standards that are stronger than the federal government's. Washington is part of a bipartisan, multistate coalition challenging this move. In 2026, the U.S. Environmental Protection Agency repealed the "endangerment finding," illegally undoing its own authority to regulate vehicle pollution at the federal level. Washington and 38 other jurisdictions challenged that action in federal court.

If the court rules in Washington's favor, the state's current standards will remain in full force. If the federal government's actions are upheld, all state and federal regulations on vehicle pollution will be weakened or eliminated. The contingency plan proposed by Ecology would reinstate older standards that have so far been unaffected by federal actions. While these standards are not as strong as what Washington currently has in place, they would ensure that the state has the strongest standards available.

All gas- and diesel-powered vehicles sold in Washington already meet the criteria laid out in the older standards, and drivers and businesses that have purchased a vehicle in the state previously won't be affected by these changes. Meanwhile, Ecology and other state agencies are exploring new policies to make clean vehicles more affordable and accessible through Governor Ferguson's ZEVergreen effort.

The rulemaking also includes other changes, such as gathering more data from businesses with vehicle fleets to support electrification planning and funding. Ecology is holding public meetings on the rule in early August and accepting public comments until 11:59 p.m. on Aug. 13, 2026. More information about this rulemaking, including links to rulemaking documents and a full list of changes being considered, is available on the rulemaking website.