About this rulemaking 

Ecology is considering amendments to the Clean Fuels Program Rule (chapter 173-424 WAC) and the program's fee structure in WAC 173-455-150. This rulemaking includes implementing House Bill (HB) 1409, which amended the carbon intensity standard for the Clean Fuel Standard (CFS). The Legislature determined that the program should reduce the carbon intensity (CI) of transportation fuels in Washington by 45% below 2017 levels by 2038. The law requires Ecology to set annual reduction targets for years 2028 through 2038. 

Comment by September 30

We have released a discussion paper for public input to outline Ecology’s options for updating the CFS’s carbon intensity reduction schedule in alignment with House Bill 1409. This paper: 

• Outlines Ecology’s statutory requirements;

• Shares where Ecology can make choices in rule, and possible scenarios for the 2028-2038 CI reduction schedule;

• Summarizes public comments received on this topic so far;

• Asks questions for public input.

Read the discussion paper and submit feedback starting September 8, 2026 at 12:00 am until September 30 at 11:59 pm. Your comments will help the team develop rule language and inform analysis for the rulemaking including the Environmental Justice Assessment.

• Visit our rulemaking webpage 

• Learn more about the rulemaking process (video) 

• Subscribe to the Washington Clean Fuel Standard email list to learn about rulemaking updates and opportunities for public participation. 

For more information, contact Lauren Sanner at lauren.sanner@ecy.wa.gov for general questions about the rulemaking. Contact cfs@ecy.wa.gov for policy questions and WFRSAdmin@ecy.wa.gov for questions about quarterly reporting, fuel pathway applications, and other technical questions.