New Hampshire Clean Diesel Grant Program

The New Hampshire Clean Diesel Grant Program is a competitive reimbursement opportunity designed to reduce harmful emissions from older diesel engines throughout the state. Funded by the U.S. Environmental Protection Agency (EPA) through the Diesel Emissions Reduction Act (DERA), the program is administered by the Technical Services Bureau within the Air Resources Division of the New Hampshire Department of Environmental Services (NHDES). Its primary aim is to improve public health and air quality by lowering nitrogen oxides (NOx), particulate matter (PM), and carbon dioxide (CO2) emissions. The program targets outdated diesel-powered vehicles and equipment that still operate across the state, which significantly contribute to air pollution and related health problems. Since its inception in 2015, the program has awarded roughly $3.25 million to eligible projects, achieving measurable reductions of 272 tons of NOx, 9.9 tons of PM, and 10,000 tons of CO2. The current round makes approximately $315,000 available to support projects that reduce emissions from on-road and non-road diesel vehicles, engines, and equipment. Eligible activities include vehicle and equipment replacement, engine replacement, and the installation of idle reduction or aerodynamic technologies. The allowable funding percentage varies by project type and fuel technology. For instance, replacing diesel with electric vehicles may be reimbursed up to 45% of project costs, whereas replacing with newer diesel models may be reimbursed up to 25%. The program is open exclusively to public entities within New Hampshire, such as municipalities, state agencies, public schools, public transit agencies, and public institutions of higher education. Each project must meet ownership, operational, and remaining life criteria. For instance, the existing diesel-powered units must have been in service with the applicant for at least two years, must be operational, and must meet minimum usage thresholds (e.g., 7,000 miles per year for highway vehicles). All replacement projects also require the original unit to be fully scrapped after the new unit is put into service. Applications are reviewed on a rolling basis, with submissions due by midnight on the 20th of each month. NHDES evaluates proposals promptly and notifies applicants within five business days of each monthly deadline. Applications must follow the prescribed format outlined in Appendix A1 for equipment replacement projects or Appendix A2 for idle reduction proposals. Submission must be completed electronically via email, using the specified subject line format. If applicants cannot submit electronically, they are encouraged to contact the program administrator for alternatives. Projects will be scored based on their clarity, feasibility, and emissions reduction potential, along with cost-effectiveness for reducing NOx, PM2.5, and CO2. Additional points may be awarded to projects that benefit designated Priority New Hampshire Communities or utilize alternative fuels such as battery-electric, hydrogen fuel cells, or compressed natural gas. The total maximum score is 125 points, with 100 from core evaluation criteria and 25 from bonus categories. All projects must be completed by September 30, 2026, which includes installation, registration, scrappage, and submission of reimbursement documentation. The effective start date for each project begins upon approval by the Governor and Executive Council. For support and questions, applicants are directed to email ms-grants@des.nh.gov or call (603) 271-8330. The program’s RFP, eligibility guidelines, work plan, and priority community list are available on the NHDES website for reference.

Projects serving designated Priority New Hampshire Communities or using battery-electric or alternative fuel technologies may receive bonus points. Ensure applications are clear, complete, and submitted by the 20th of the month.