Diesel Vehicle Information

Diesel Anti-Idling Campaign

Diesel Emission Health and Environmental Effects

Information concerning health and environmental effects related to diesel emissions.


Links to Maryland regulations relevant to the Diesel Vehicle Emissions Control Program and to Federal regulations regarding diesel fuel and emissions.

Diesel Fact Sheets

Detailed information regarding diesel-related topics, including biodiesel fuel, retrofit technology, and idling technology.

Diesel Retrofit Projects

Information regarding the Maryland Department of the Environment's diesel retrofit projects, including retrofits of trash haulers, dump trucks, transit buses, school buses, emergency vehicles, off-road vehicles, and quick charge electric vehicle chargers.

Diesel Vehicle Emissions Control Program (DVECP)

Information pertaining to the DVECP, what to do if a vehicle fails the diesel emissions test, and how to become a certified diesel emissions retester (CDER).

Statewide Contract for Purchase of Diesel Emission Control Devices

These annual blanket purchase orders (BPOs), for parts and labor, have met Maryland's specifications, terms, and conditions to retrofit heavy-duty diesel vehicles.

Certified Diesel Emissions Retesters

Information on what are Certified Diesel Emissions Retesters (or CDERs) and how to become one.

Failing the Emission Test

Information for vehicles registered in and outside of Maryland, and state smoke opacity standards.

Useful Web Links​

Links to useful diesel and mobile sources-related websites.

Contact Information

For additional information, contact Tim Shepherd at (410)537-3270 or email tim.shepherd@maryland.gov.​

Human Trafficking GET HELP

National Human Trafficking Hotline - 24/7 Confidential

1-888-373-7888 233733 More Information on human trafficking in Maryland

Customer Service Promise

The State of Maryland pledges to provide constituents, businesses, customers, and stakeholders with friendly and courteous, timely and responsive, accurate and consistent, accessible and convenient, and truthful and transparent services.

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Help Stop Fraud in State Government

The Maryland General Assembly’s Office of Legislative Audits operates a toll-free fraud hotline to receive allegations of fraud and/or abuse of State government resources. Information reported to the hotline in the past has helped to eliminate certain fraudulent activities and protect State resources.

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