New Hampshire is moving to leave a regional agreement aimed at limiting ozone pollution, after state lawmakers passed legislation to eliminate yearly vehicle inspections starting early next year.
The change, which was tucked into the 2025 state budget, gained support from those who saw annual inspections as a scam that benefits auto dealers and mechanics. The state expects to lose money because of the elimination.
Annual inspections include an emissions test that shows whether a vehicle is meeting legal limits for pollutants. Maintaining that inspection program is part of how New Hampshire stays in compliance with federal clean air regulations, and removing inspections without approval from the Environmental Protection Agency could lead to federal repercussions, like the withholding of highway funding.
Vehicle emissions like nitrogen oxides are one of the main components of ozone, which causes smoggy conditions and may lead to health issues for those who breathe it in. About half of New Hampshire’s air pollution that causes ozone to form comes from vehicles.
For a group of states in New England and the Mid-Atlantic, ozone has been especially difficult to manage. The Clean Air Act created a regional agreement among those states to help them work together to limit ozone pollution. The federal law also requires vehicle inspections in areas that have experienced high concentrations of ozone in the past, which New Hampshire has.
To eliminate inspections, New Hampshire must change its “state implementation plan,” a document every state must develop to show how it will meet federal pollution requirements.
Removing something from an implementation plan is uncommon, said Catherine Beahm, a regulator with the New Hampshire Department of Environmental Services. In 2024, state regulators submitted testimony outlining how the move could subject the state to federal sanctions.
But, Beahm said, modeling her agency has done shows that removing yearly vehicle tests won’t cause the state to contribute to excess emissions in the region — an argument regulators will make to the Environmental Protection Agency as they ask for approval to end inspections.
“Our air quality is very good. It has gotten better over time, and we believe that we do not need the inspection and maintenance program to continue to meet the federal standards,” Beahm said.
Since the federal standards were implemented in 1971, parts of New Hampshire continued to have had ozone levels exceeding federal limits for decades. But since 2012, the whole state has been meeting ozone emissions requirements.
“Every year, more and more cars are bought that are newer, cleaner, meet the federal tier level of clean cars,” Beahm said.
If the modeling done by state officials had not shown that emissions were slated to continue decreasing, New Hampshire would have needed to come up with another program to replace the emissions inspections to help stay in compliance. Instead, the state plans to just remove this one part of its implementation plan, which includes a range of other state laws aimed at reducing pollution.
Getting rid of vehicle inspections is a concern for Dan Bennett, president of the New Hampshire Automobile Dealers Association.
“Our concern is that New Hampshire potentially could become a dumping ground for those vehicles in those other states that cannot get a pass,” he said. “They’ll all wind up on our shores, on our front lawn, which will negatively affect the car-buying public.”
Inspection programs, he said, are like preventative doctor’s visits. They allow drivers to diagnose an issue — like an emissions control system problem — and prevent failure.
The deadline for sharing written comments on the state’s request to be allowed to opt out of the regional ozone agreement is Friday, November 21. More instructions are available online.
