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Clean Diesel

Contact Us About Clean Diesel

Mailing Address:
US EPA Clean Diesel
1200 Pennsylvania Ave
Mail Code 6406A
Room 5358K (Overnight) 
Washington, DC 20450

Report a Violation
Report possible violations
of environmental laws and regulations

Clean Diesel Helpline

For information about clean diesel funding or diesel technologies, contact our helpline.
Phone: 1-877-623-2322
Email: Clean Diesel Helpline (

Clean Diesel News

Receive email updates on clean diesel funding, issues, and resources.

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Diesel Emission Quantifier (DEQ) Helpline

For information about the Diesel Emission Quantifier, contact our helpline.
Email: Diesel Emission Quantifier Helpline (

Questions and Comments

Please use the form below to send us questions or comments. Be sure to include your e-mail address if you’d like a response.