Resources and Links

Diesel Emissions Reduction – General

The EPA Office of Tranporatation and Air Quality (OTAQ) periodically submits Reports to Congress highlighting the benefits of the Diesel Emissions Reduction program.

Diesel Emissions Reduction Act (DERA) Program

Diesel Retrofits: Quantifying and Using Their Benefits in SIPs and Conformity -- Guidance for State and Local Air and Transportation Agencies (February 2014)
This document provides guidance on quantifying and using emission reductions from highway and nonroad diesel vehicles, engines, and equipment that have been retrofitted. The guidance discusses how emission reductions from diesel retrofit projects can be used in a SIP and in transportation conformity and general conformity determinations, based on the new MOVES methodology described in this guidance.

For more information on Transportation Conformity, visit

A Guide to Understanding and Accessing the Congestion Mitigation and Air Quality (CMAQ) Program (Diesel Technology Forum, April 2007)
The CMAQ Program is quite complex, which when added to the variability of its administration from state to state, makes it extremely difficult to assess the process and prospects for competing for these funds. The Diesel Technology Forum, with assistance from the Emissions Control Technology Association, has written this guide to assist those wishing to learn more about the potential funding opportunities available under this program. Includes case studies, insight into CMAQ's administration, and suggestions on how to increase the competitiveness of diesel retrofit applications.

Diesel Emissions Reduction Technologies

Clean Diesel Truck Video Training
Clean diesel trucks (with 2007 or newer engines) are ten times cleaner than older diesel trucks. But they also have complicated pollution control systems. Understanding how newer trucks and their pollution control systems work is important to avoiding expensive engine repairs. This video training course will guide you through the differences between older diesel trucks and newer, cleaner diesel trucks. It will also show you how to take care of a clean diesel truck.

Locomotive Idle Reduction Options (November, 2011)
Tom Balon, M.J. Bradley and Associates LLC

2014-18 Medium & Heavy Duty Final Rule (presented November, 2011)
Joint Briefing for Congressional Staff 9 August 2011

Non-Road Diesel Engines: Technologies for Reducing Fuel Consumption & Emissions (November, 2011)
Wayne Clark, Milton-CAT

Impacts of Advanced Combustion, Fuels and Aftertreatment Technologies on Diesel PM Emissions
California Air Resources Board
Sacramento, CA
February 11, 2009
This presentation traces the development of diesel engine emissions control technologies since the mid-1990's and provides a vision of future diesel technologies with an emphasis on PM and MSAT emissions.

The Cost-Effectiveness of Heavy-Duty Diesel Retrofits and Other Mobile Source Emission Reduction Projects and Programs (Office of Transportation and Air Quality, U.S. Environmental Protection Agency, May 2007)
The U.S. Environmental Protection Agency's Office of Transportation and Air Quality prepared a report that provides estimates of emissions reductions and cost effectiveness of retrofit technologies and other mobile source measures. The document focuses on CMAQ-eligible projects and encourages agencies to consider cost effectiveness, air quality and health effects when deciding how to invest air quality resources.

Diesel Retrofit Technology: An Analysis of the Cost Effectiveness of Reducing Particulate Matter and Nitrogen Oxides Emissions from Heavy-Duty Nonroad Diesel Engines Through Retrofits (Office of Transportation and Air Quality, U.S. Environmental Protection Agency, May 2007)
The U.S. Environmental Protection Agency's Office of Transportation and Air Quality prepared a technical analysis of the cost effectiveness of retrofitting existing heavy-duty diesel nonroad engines to reduce particulate matter (PM) and nitrogen oxides (NOx). This report demonstrates how nonroad diesel retrofits can be a cost effective strategy for reducing air pollutants. It expands on an earlier analysis and previous technical report on retrofit cost effectiveness by analyzing more nonroad applications and estimating the cost effectiveness of various NOx strategies.

Locomotive and Marine Emission Reduction (October 2006)
Tom Balon, MJ Bradley & Associates

Health Effects of Diesel

Health Effects from Exposure to Diesel Exhaust and Other Mobile Source Pollution
Motor vehicle emissions contribute to ambient levels of air toxics known or suspected as human or animal carcinogens. Exposures to air toxics can also cause noncancerous health effects, such as neurological, cardiovascular, respiratory, reproductive and/or immune system damage.

National Air Toxics Assessment
In August 2018, EPA released the results of its 2014 National Air Toxics Assessment (NATA). NATA helps assess which air toxics and emission source types may pose health risks. NATA also helps EPA and other agencies determine which places may need further study to better understand risks.

Health Effects Institute: Extended Follow-Up and Spatial Analysis of the American Cancer Society Study Linking Particulate Air Pollution and Mortality
(May 2009)
Daniel Krewski et al.

Fine-Particulate Air Pollution and Life Expectancy in the United States (January 2009)
C. Arden Pope III, Ph.D., Majid Ezzati, Ph.D., and Douglas W. Dockery, Sc.D.
This article in the New England Journal of Medicine examines exposure to fine-particulate air pollution. Such exposure has been associated with increased morbidity and mortality, suggesting that sustained reductions in pollution exposure should result in improved life expectancy. This study directly evaluated the changes in life expectancy associated with differential changes in fine particulate air pollution that occurred in the United States during the 1980s and 1990s.

Ultrafine Particles: Issues Surrounding Diesel Retrofit Technologies for Particulate Matter Control (February, 2007)
Phil Johnson and Paul J. Miller, NESCAUM

Diesel Particulate Filters and Ultrafine Particles (December 2006)
Northeast Diesel Collaborative

Ultrafines from Emission Control Devices: Results from the Real World (October 2006)
Aniket Sawant, Ph.D.
Johnson Matthey Inc.

DPFs—Is There An Ultrafine Problem? CATF's Investigations and Response (October 2006)
L. Bruce Hill Ph.D., Senior Scientist
Clean Air Task Force

The Burden of Asthma
Asthma is a chronic (or lifelong) disease that can be serious—even life-threatening. There is no cure for asthma. The good news is that with proper management, you or your loved one with asthma can live a normal, healthy life. The more you can learn about asthma, the better you and your loved ones can manage living with this disease, making the most of every day and maintaining a high quality of life.

2005 Research Highlights: Health Effects of Particulate Matter and Ozone Air Pollution (January 2006)
American Lung Association

Evaluating the Occupational and Environmental Impact of Nonroad Diesel Equipment in the Northeast (March 2004)
This evaluates the potential health risks from nonroad sources by monitoring selected hazardous air pollutant and particulate matter exposures in the cabin of operating nonroad diesel equipment and at the perimeter of the active work site.

Alternative Fuels

For a comprehensive list of alternative fuel laws and incentives, please visit the Department of Energy's Alternative Fuels Data Center.

Technical Report: Experimental Trial Using Biodiesel Fuel in Heavy Fleet Vehicles (Maine Department of Transportation - Transportation Research Division, May 2004)
From July 2003 to April 2003, Maine DOT used a blend containing 20% of biodiesel fuel (B20) in five pieces of mobile equipment and in two furnaces at the Freeport Maintenance Facility, in lieu of conventional diesel fuel. This study found that biodiesel costs 40 to 50 cents more per gallon than conventional diesel.

Maine Department of Transportation letter to Transportation Providers
(October 2006)
On October 19, 2006 the Maine Department of Transportation, Office of Passenger Transportation (DOT/OPT) sent a letter to transportation providers in the state advocating the use of biodiesel in diesel powered buses.


Diesel Engine Retrofits in the Construction Industry: A How To Guide
In January 2008, the Massachusetts Department of Environmental Protection issued a comprehensive "how to" guide for retrofiting diesel construction equipment with advanced pollution control technologies. The 56 page document includes the following: an overview of the health and air quality concerns associated with diesel pollution, the Massachusetts state agency construction retrofit requirements, available retrofit technologies, a retrofit "roadmap", and case studies of successful projects.

Diesel Retrofits: Today and Tomorrow Off-Road Experience (October 2006)
Marty Lassen
Johnson Matthey

Emission Reduction Incentives for Off-Road Diesel Equipment Used in the Port and Construction Sectors (ICF/EPA 2005)
This report describes and assesses incentive programs to reduce emissions from off-road diesel engines used in the construction industry and port sector. The report focuses primarily on grant programs, tax incentives, modified contracting procedures, and non-monetary incentives implemented at the federal, state, regional, and local level.


FHWA Talking Freight Seminar Series
The Federal Highway Administration's (FHWA's) Office of Freight Management and Operations and the Office of Planning host the "Talking Freight" seminars. The seminars are part of a broader Freight Professional Development Program aimed at providing technical assistance, training, tools, and information to help the freight and planning workforce meet the transportation challenges of tomorrow. Seminars are held via web conference on a monthly basis throughout the year and are open at no cost to all interested parties in both the public and private sectors. There is no special equipment required to participate, all that is needed is a computer with Internet connectivity to view the presentations and audio can either be heard over the computer or phone.

Compendium of Current State Idling Regulations
The American Transportation Research Institute (ATRI) publishes a compendium of current idling regulations by state, which is provided for free in two different PDF formats -- the original compendium listing and as a foldable cab card for quick reference. ATRI updates the compendium regularly.


Locomotive and Marine Emission Reduction (October 2006)
Tom Balon, MJ Bradley & Associates

Scoping Study to Evaluate Locomotive Emissions Operating in New Haven, Connecticut and Potential Control Options (NESCAUM, June 2006)
The locomotive fleet in and around New Haven, Connecticut includes line-haul freight, commuter, intercity rail, and switch locomotives. To better characterize pollution from locomotives operating in and around New Haven, NESCAUM has developed a preliminary inventory of locomotive emissions in the New Haven area, and has evaluated potential control options to reduce locomotive pollution. This report presents the findings of this work and focuses on emissions in New Haven and Fairfield since most of the rail activity in Connecticut takes place in these two densely populated counties.

New England Rail Expo and Forum - March 28, 2006
The Northeast Diesel Collaborative hosted a special seminar at the 2006 New England Rail Expo & Forum. This seminar examined key issues facing railroad operators today, including new and emerging technologies that can save fuel and reduce emissions, a review of upcoming fuel regulations and their effects on the rail industry in the Northeast, funding opportunities including low interest loans, an examination of New York Container Terminal's choice to use on-dock hybrid locomotives, and the Port Authority of New York & New Jersey's intensive capital redevelopment on-dock and regional rail improvement program.


Commercial Harbor Craft Regulation Implementation
California Air Resources Board
Sacramento, CA
February 11, 2009
This presentation describes the structure, rules, and exemptions related to the commercial harbor craft regulations that became effective January 1, 2009 for vessels within regulated California waters.

NEDC Goods Movement Work Group
by Guiselle Aldrete
September 17, 2008
This presentation covers lessons learned from ports about various technologies, emission reduction strategies, and what lies ahead for East Coast ports.

EPA New England Options for the Marine Ports Sector: Green Strategies for Sustainable Ports (June 2008)
This document provides marine port authorities and terminal operators with an overview of strategies that can be implemented to reduce air emissions from daily operations. These strategies are organized to provide a tiered approach to "greening port operations" based on cost and existing infrastructure, beginning with low cost/no cost strategies.

Locomotive and Marine Emission Reduction (October 2006)
Tom Balon, MJ Bradley & Associates

Emission Reduction Incentives for Off-Road Diesel Equipment Used in the Port and Construction Sectors (ICF/EPA 2005)
This report describes and assesses incentive programs to reduce emissions from off-road diesel engines used in the construction industry and port sector. The report focuses primarily on grant programs, tax incentives, modified contracting procedures, and non-monetary incentives implemented at the federal, state, regional, and local level.

San Pedro Bay Ports Clean Air Action Plan
The Clean Air Action Plan identifies strategies to reduce pollution from every source – ships, trucks, trains, cargo-handling equipment and harbor craft.


The Massachusetts Bay Transportation Authority, more commonly known as the T, is one of the oldest public transit systems in the United States. It's also the largest transit system in Massachusetts.
As a division of the Massachusetts Department of Transportation (MassDOT), the MBTA provides subway, bus, Commuter Rail, ferry, and paratransit service to eastern Massachusetts and parts of Rhode Island.

The Metropolitan Transportation Authority is North America's largest transportation network, serving a population of 15.3 million people across a 5,000-square-mile travel area surrounding New York City through Long Island, southeastern New York State, and Connecticut.

NJ TRANSIT is New Jersey's public transportation corporation. Its mission is to move New Jersey and the region by providing safe, reliable and affordable public transportation that connects people to their everyday lives, one trip at a time.  Covering a service area of 5,325 square miles, NJ TRANSIT is the nation's third largest provider of bus, rail and light rail transit, linking major points in New Jersey, New York and Philadelphia. The agency operates an active fleet of 2,221 buses, 1,231 trains and 93 light rail vehicles. On 251 bus routes and 12 rail lines statewide, NJ TRANSIT provides nearly 270 million passenger trips each year.


Industry/Industry Associations
The official website of the National Biodiesel Board, the national trade association representing the biodiesel industry as the coordinating body for research and development in the United States. You can find information on biodiesel fuels, as well as where to find distribution and retail locations.

Diesel Technology Forum
The Diesel Technology Forum is a not-for-profit organization dedicated to raising awareness about the importance of diesel engines, fuel and technology.

The Manufacturers of Emission Controls Association
The Manufacturers of Emission Controls Association (MECA) is a non-profit association incorporated in Washington, D.C. It was formed in 1976 to provide solid technical information on emission control technology for motor vehicles. As the emission control industry grew in the subsequent decades, and as its member companies expanded control technology products to other sources, MECA's mission expanded as well. Today, MECA's members include leading manufacturers of a variety of emission control equipment and efficiency technologies for: 1) automobiles, trucks, and buses; 2) off-road vehicles; and 3) stationary sources.

State Agencies, Legislation, and Plans


Connecticut Department of Energy and Environmental Protection


Maine Department of Environmental Protection - Bureau of Air Quality


Massachusetts Department of Environmental Protection

New Hampshire

New Hampshire Department of Environmental Services

New Jersey

New Jersey Department of Environmental Protection

New York

New York Department of Environmental Conservation

Puerto Rico

Puerto Rico Department of Environment & Natural Resources

Rhode Island

Rhode Island Department of Environmental Management - Office of Air Resources

US Virgin Islands

Department of Planning and Natural Resources

EPA's work in the U.S. Virgin Islands is managed from the EPA office in New York City. Learn more about EPA Region 2.


Vermont Department of Environmental Conservation - Air Quality and Climate Division

Regional and Local Initiatives

Mid-Atlantic Diesel Collaborative: A new regional effort to reduce diesel related emissions in the Mid-Atlantic region.

Mid-West Clean Diesel Initiative: A public-private partnership to reduce diesel emissions from diesel engines in the Midwest.

NESCAUM: The Northeast States for Coordinated Air Use Management is a nonprofit organization that represents the interests of the air quality agencies of the eight northeastern states.

The STRIDE Collaborative is a public-private partnership dedicated to reducing diesel emissions and improving public health in the eight southeastern states.

US Environmental Protection Agency Region 1: Serving Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont and 10 Tribal Nations.

US Environmental Protection Agency Region 2: Serving New Jersey, New York, Puerto Rico and the US Virgin Islands

West Coast Collaborative: A public-private partnership working to reduce air pollution emissions from diesel sources along the West Coast.

National Initiatives

Clean Cities: A U.S. Department of Energy program aimed at advancing the nation's economic, environmental, and energy security by supporting local decisions to adopt practices that contribute to the reduction of petroleum consumption, such as alternative fuels and vehicles, fuel blends, fuel economy, hybrid vehicles, and idle reduction.

Congestion Mitigation Air Quality (CMAQ) Funds: The U.S. Department of Transportation's CMAQ program provides funds to state DOTs, MPOs, and transit agencies to invest in projects that reduce air pollution from transportation-related sources.

EPA Ports Initiative: EPA's Ports Initiative works in collaboration with the port industry, communities, and all levels of government to improve environmental performance and increase economic prosperity. This effort helps people living and working near ports across the country breathe cleaner air and live better lives.

National Clean Diesel Campaign: EPA has created the National Clean Diesel Campaign to reduce the pollution emitted from diesel engines across the country through varied control strategies and the aggressive involvement of national, state, and local partners.

SmartWay Vehicles: EPA's SmartWaySM program offers great options for drivers and shoppers who want to make greener choices when it comes to transportation.

When you buy a SmartWay certified vehicle or fill up with a renewable fuel like E85, you are helping to reduce air pollution and improve energy efficiency. It's the smart way to make an important contribution to a cleaner environment and our energy independence.

Smartway Transport: The SmartWaySM Transport Partnership is a voluntary partnership between EPA and the freight industry designed to increase energy efficiency and significantly reduce greenhouse gases and air pollution by adopting fuel-saving strategies that increase profits and reduce emissions.

US EPA's Voluntary Diesel Retrofit Program: EPA has developed the Voluntary Diesel Retrofit Program to address pollution from diesel construction equipment and heavy-duty vehicles that are on the road today.