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Diesel Retrofit Compliance Program

As diesel emission-reducing technology has improved over the years, Oregon continues to see significant pollution from older on-road diesel engines. One method to reduce these harmful emissions includes the installation of appropriate aftermarket retrofit technology.

The 2019 Oregon Legislature responded to concerns by passing HB 2007 to reduce diesel emissions across the state. The bill established deadlines, after which certain older model diesel engine vehicles cannot be titled or registered by the Oregon Department of Driver and Motor Services (For medium-duty trucks) or the Oregon Department of Transportation's Commerce and Compliance Division (for heavy-duty trucks). The new Diesel Retrofit Compliance Program only applies to eligible diesel trucks in Clackamas, Multnomah and Washington counties. These vehicles must be equipped with approved retrofit technology and certified by DEQ. The two vehicle weight classifications categorized in HB 2007 include:

  • Medium-duty diesel trucks with gross vehicle weight rating of 14,001 – 26,000 lbs. (such as certain box trucks, flatbed or service trucks).
  • Heavy-duty diesel trucks with a gross vehicle weight rating of over 26,000 lbs. (such as tractor-trailer trucks). 

Beginning Jan. 1, 2023, Oregon state agencies implemented Phase I of the Diesel Retrofit Compliance Program. Oregon DMV and CCD will not register a medium-duty, or a heavy-duty truck powered by a model year 1996 or older diesel engine in Clackamas, Multnomah and Washington counties only, unless it is first retrofitted and approved by DEQ.

As of Jan. 1, 2025, and in accordance with Phase II. of the Diesel Retrofit Compliance Program, Oregon DMV will not title specific medium- and heavy-duty diesel trucks in Clackamas, Multnomah and Washington counties only, unless they are first retrofitted and approved by DEQ. Details are as follows:

  • A medium-duty truck powered by engine model year 2009 or older diesel engine cannot be titled unless retrofitted and approved by DEQ.
  • Privately owned heavy-duty trucks powered by engine model year 2006 or older diesel engine cannot be titled unless retrofitted and approved by DEQ.
  • Publicly owned heavy-duty trucks powered by engine model year 2009 or older diesel engine cannot be titled unless retrofitted and approved by DEQ. 

Please direct all questions about registration and exemptions to DMV and CCD at the following: 

  • For medium-duty vehicles (14,001 – 26,000 lbs.), contact DMV Customer Service Assistance at 503-945-5000.
  • For heavy-duty vehicles (>26,000 lbs.), contact the Commerce and Compliance Division at CCDHB2007Inquiries@odot.state.or.us

If you have technical questions on retrofit installations only, please contact DEQ through the Diesel Retrofit Compliance Program email. DEQ is only responsible for reviewing and approving retrofitted engines and will forward all other questions to the above two agencies. 
Reminder: Annual renewal requirement and applications. See below dropdown for details.

More information

​​In preparation of submitting the online application, there are several steps vehicle owners will need to complete. Below is a checklist and summary of the application process.

Step 1: 

After completion of the vehicle retrofit installation, Oregon DEQ requires the following documents to be ready prior to submitting the application.  The Signature of Attestation will need to be completed and signed by the registered owner or authorized representative. The installer will also need to sign the Installer Certification Section. The other documents listed below should be provided by the installer.

Step 2:

Please ensure the following requirements have been prepared by the authorized installer:

  • Manufacturer/Installer pre-assessment form
  • Documentation and pictures supporting labeling requirements of retrofit system
  • Copy of warranty agreement between installer and owner

Step 3:

Please contact the Retrofit Compliance Program for information about the Approved Retrofit Technology application by email: diesel.retrofitcompliance@deq.oregon.gov

Forms:

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The Environmental Protection Agency, and California's Air Resource Board, maintain lists of currently verified retrofit technologies for on-road diesel engines, proven to achieve at least an 85% reduction in diesel particulate matter. Currently verified EPA or CARB retrofit technologies, otherwise known as diesel particulate filter or DPF systems, may qualify as Approved Retrofit Technology for Oregon's Retrofit Compliance Program. To meet the criteria for Approved Retrofit Technology, DEQ will need to verify that the technology meets the following:

  • The new equipment is manufactured for installation on an on-road diesel engine and compatible with the medium- or heavy-duty truck;
  • Provides at least 85% reduction of diesel particulate matter and currently verified by EPA or CARB;
  • Installed by an installer authorized by the Approved Retrofit Technology manufacturer;
  • Has a valid manufacturer's warranty; and​
  • Complies with labeling and inspection requirements.

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As of 2024, the DEQ Diesel Retrofit Compliance Program has begun the next phase of requirements for regulated vehicle owners. See Annual Renewal Inspection Requirements timeline for a brief description.

As detailed in the Annual Renewal Inspection timeline, regulated owners are required to have an opacity test and a visual inspection of the regulated vehicle prior to applying for certification renewal. Tests must be performed by a DEQ authorized installer. Please complete the Annual Renewal application along with inspection/test results and submit to DEQ using the HDD Online Application. Annual applications may be found above, through the “More information" section.​

​​​The Environmental Quality Commission, Oregon DEQ's formal policy and rulemaking body, adopted the Diesel Retrofit Compliance rules on July 23, 2021. The rules provide additional details and clarity to the direction provided in HB 2007 (2019) related to approved retrofit technologies and program implementation. They establish the criteria for approved retrofit technologies for on-road diesel engines, the manner by which Oregon DEQ will certify them and the verification required to ensure continued certification for those technologies. The certificate of retrofit compliance, issued by DEQ, would allow the owner to renew or title a vehicle per the Oregon Vehicle Code found in Oregon Department of Transportation Statute Chapter 803.

​Please follow the links provided to find the diesel retrofit compliance rules:


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HB 2007 (2019) authorized DEQ's Diesel Emissions Mitigation Grant Program to provide grant funding, subject to availability, to support the purchase of retrofit systems, as well as cleaner burning engines and diesel equipment replacements. Vehicle owners who apply and are awarded the grant funding, will be eligible for up to 100% of the retrofit technology cost. DEQ intends to have approximately $8 million available each year beginning in 2021 with a target of providing at least five years of funding based on available revenue. Please refer to our Diesel Emissions Mitigation Grants web page for key dates and more detailed information.

Contacts

Please contact the DEQ Diesel Retrofit Compliance Program for any questions regarding this program: diesel.retrofitcompliance@deq.oregon.gov  

David Glomski
Operations and Policy Analyst
Portland Area: 503-229-5066
Toll-Free in Oregon: 877-476-0583