Exhaust from diesel engines is a significant contributor to air pollution. It has been classified as "likely to be carcinogenic" by EPA and the California Air Resources Board has included particulate emissions from diesel vehicles on its list of Toxic Air Contaminants.

DEEP's initial clean diesel efforts prioritized the installation of emission controls on school buses because of health risks posed to children by diesel exhaust. A variety of funding sources were leveraged to reduce children’s exposure to fine particulate matter in diesel exhaust, which can aggravate asthma, bronchitis and other cardiovascular conditions. Connecticut’s school bus retrofit programs are detailed on the Connecticut Clean School Bus Program web page.

With increased funding available from the federal Diesel Emission Reduction Act (DERA) through EPA’s National Clean Diesel Campaign and the State Grants & Funding Program, DEEP has broadened the scope of our efforts to capitalize on these retrofit, repower, replacement and idle reduction opportunities for construction, fleet and marine applications. DERA funding is also covering diesel emission reduction projects for transit, locomotives and port operations.

Other projects to reduce diesel emissions have been made possible through the U.S. Department of Energy’s Clean Cities Program.  The Clean Cities Coalitions in Connecticut have advanced the use of alternative fuels and fueling infrastructure in the state, which effectively decreases emissions from both gasoline and diesel-powered vehicles.  The Connecticut Department of Transportation also works with agencies and planning organizations to reduce diesel emissions using the Federal Highway Administration’s Congestion Mitigation Air Quality program.

DEEP’s diesel grants and funding efforts since 2008 have leveraged over $5 million from the state and national DERA, the federal American Recovery and Reinvestment Act (aka Stimulus Act) and the Connecticut Clean School Bus Act to reduce diesel emissions that impact both the environment and the passengers on these vehicles.

Diesel Retrofit Efforts in Connecticut*