An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »


Learn About Impacts of Diesel Exhaust and the Diesel Emissions Reduction Act (DERA)

As a result of EPA regulations, diesel engines manufactured today are cleaner than ever before. But because diesel engines can operate for 30 years or more, millions of older, dirtier engines are still in use.  Reducing exposure to diesel exhaust from these engines is especially important for human health and the environment.  EPA offers funding for projects that reduce diesel emissions from existing engines.

Impacts of Diesel Emissions

Human health, our environment, global climate and environmental justice are all affected by diesel emissions.

Human Health - Exposure to diesel exhaust can lead to serious health conditions like asthma and respiratory illnesses and can worsen existing heart and lung disease, especially in children and the elderly.  These conditions can result in increased numbers of emergency room visits, hospital admissions, absences from work and school, and premature deaths.

Environment - Emissions from diesel engines contribute to the production of ground-level ozone which damages crops, trees and other vegetation.  Also produced is acid rain, which affects soil, lakes and streams and enters the human food chain via water, produce, meat and fish.  These emissions also contribute to property damage and reduced visibility.

Global Climate - Climate change affects air and water quality, weather patterns, sea levels, ecosystems, and agriculture. Reducing greenhouse gas (GHG) emissions from diesel engines through improved fuel economy or idle reduction strategies can help address climate change, improve our nation's energy security, and strengthen our economy.

Environmental Justice - EPA seeks to provide all people the same degree of protection from environmental and health hazards and equal access to decision-making to maintain a healthy environment in which to live, learn, and work.  DERA activities further EPA’s commitment to reduce health and environmental harm from diesel emissions in all communities throughout the country.

Top of Page

Diesel Emission Reduction Act (DERA)

Authority for DERA funding comes from the Diesel Emissions Reduction Act, part of the Energy Policy Act of 2005 (PDF) (551 pp, 3.16 MB, August 2005, About PDF). As stipulated in the Act

  • Seventy percent of the DERA appropriation is to be used for national competitive grants and rebates to fund projects that use EPA or California Air Resources Board (CARB) verified or certified diesel emission reduction technologies.
  • Thirty percent of the DERA appropriation is allocated to the states and territories to fund programs for diesel emissions reduction projects. Base funding is distributed to states and territories using a formula based on overall participation.  Additional incentive funding is available to states and territories that provide matching funds.

Diesel Emissions Reduction Act Grants (DERA 2012-2016)

The Diesel Emissions Reduction Act of 2010 (PDF)(7 pp, 133 K, January 2011, About PDFreauthorized DERA grants to eligible entities for projects that reduce emissions from existing diesel engines. The bill authorizes up to $100 million annually for FY2012 through FY2016 and allows for new funding mechanisms, including rebates.

Diesel Emissions Reduction Act Grants (DERA 2007-2011)

The Diesel Emissions Reduction Program (known as "DERA") was created under the Energy Policy Act of 2005 (PDF) (551 pp, 3.16 MB, August 2005, About PDF). This act gave EPA new grant and loan authority for promoting diesel emission reductions and authorized appropriations to the Agency of up to $200 million per year for FY2007 through FY2011. Congress appropriated funds for the first time under this program in FY2008.

The American Recovery and Reinvestment Act of 2009 (ARRA) provided $300 million in new funding for national and state programs for the implementation of verified and certified diesel emission reduction technologies. Recovery Act funding for the National Clean Diesel Campaign (now known as Diesel Emissions Reduction Act (DERA) Funding Program) allowed for the implementation of many additional projects.

Top of Page

Federal Funding

  • is a single access point for over 900 grant programs offered by the 26 Federal grant-making agencies. You can use ‘Search Grants’ using keywords or more specific criteria.
  • Catalog of All Federal Domestic Assistance This online catalog provides a full listing of all federal programs available to state, local and DC governments; federally-recognized Tribal governments; US territories and possessions; and domestic public, quasi- public, and private profit and nonprofit organizations.

Top of Page