The U.S. Environmental Protection Agency (EPA) is offering $26 million in grant funding to fleets to reduce diesel emissions from the nation’s existing fleet of diesel engines, the agency announced.

Roughly 90% of the nation’s freight tonnage is moved by diesel-powered engines, including highway freight trucks, locomotives, and commercial marine vessels.

The EPA is requesting proposals nationwide for projects that will reduce diesel emissions and exposure, especially from fleets in areas that are designated as having poor air quality. The funding will be prioritized to projects that benefit local communities and applicants that promote and continue efforts to reduce emissions after a project has ended.

Applicants permitted to compete for the funding include regional, state, local or tribal agencies, or port authorities with jurisdiction over transportation or air quality. Nonprofit organizations are also permitted to apply as long as they provide pollution reducation or educational services to diesel fleet owners, or if the organization focuses on the promotion of transportation or air quality.

The deadline to apply is April 26.