EPA Expedites Review of Requests from New Hampshire Under the Clean Air Act

EPA Expedites Review of Requests from New Hampshire Under the Clean Air Act

March 23, 2026

BOSTON (March 23, 2026) - In accordance with U.S. Environmental Protection Agency (EPA) Administrator Lee Zeldin's commitment to cooperative federalism, EPA is expeditiously working to review the state of New Hampshire's two Clean Air Act (CAA) submissions seeking to repeal the state's vehicle inspection and maintenance (I/M) program and to remove the state from the Ozone Transport Region (OTR) ahead of the typical 18-month timeline. In June 2025, New Hampshire Governor Kelly Ayotte signed a law repealing the state's Vehicle Emissions I/M program, including the emissions testing program in its entirety.

In December 2025, New Hampshire asked the EPA to approve a change to its State Implementation Plan (SIP) that would remove the state's vehicle inspection and maintenance (I/M) program. Currently, New Hampshire is part of the Ozone Transport Region (OTR), a group of northeastern states required to include ozone-reduction measures in their SIPs, even if they already meet federal ozone standards. Because of this, New Hampshire's SIP includes the I/M program. Under the Clean Air Act (CAA), the state must get EPA approval before implementing its June 2025 law to end the program. To do that, New Hampshire must first be removed from the OTR.

EPA has up to 18 months to decide on state petitions under the CAA, but after receiving New Hampshire's petitions on December 24, 2025, the agency plans to move much faster. The EPA expects to share its proposed decision by early summer and issue a final decision before the end of the year, well ahead of schedule. This reduced timeline shows the Trump EPA's focus on working closely with states to adhere to all statutory requirements and finish projects efficiently. Before the final decision is made, the public will have a chance to weigh in on the proposal.

"This process is a direct reflection of cooperative federalism based on New Hampshire's needs. EPA is working at record speed with the state to ensure all decisions are made in accordance with requirements under the Clean Air Act and to provide the people of New Hampshire relief from burdensome regulations," said EPA Administrator Zeldin. "The Trump EPA firmly believes that collaborating with our state air partners is the best way to deliver results and ensure clean air for all Americans."

"New Hampshire is a valued partner in protecting air quality across New England," said EPA Regional Administrator Mark Sanborn. "We will continue to work with all New England states to ensure EPA meets our mission of protecting human health and the environment."

Background

Ozone Transport Region - The CAA sets out specific requirements for a group of northeast states that make up the OTR. States in the OTR are required to include in their SIPs certain measures addressing emissions of pollutants that form ozone, even if the states already meet the ozone standards.

SIPs are a collection of regulations and documents used by a state, territory, or local air district to implement, maintain, and enforce the National Ambient Air Quality Standards (NAAQS), and to fulfill other requirements of the CAA. Examples of EPA-approved documents and materials associated with a SIP may include NAAQS attainment and maintenance plans, preconstruction permitting programs, stationary source emission control regulations, vehicle I/M plans, stack testing and monitoring rules, and more.