Washington State’s Department of Ecology (Ecology) has adopted amendments for the Clean Fuels Program Rule effective November 20th, 2025. The main updates are summarized below.
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Carbon Intensity Standards
The amendments revise statewide CI benchmarks requiring a 7% reduction from 2017 levels, previously set to be reduced by 3%. The latest CI standards for gasoline and diesel are shown.
Gasoline CI Standards
| Calendar Year | Washington Carbon Intensity Standard (gCO2e per MJ) | Percent Reduction |
| 2025 | 96.95 | 2% |
| 2026 | 92.00 | 7% |
| 2027 | 88.04 | 11% |
| 2028-2037 | To be established in future rule making | 3% to 4% per year |
| 2038 | 54.41 | 45% |
Diesel CI Standards
| Calendar Year | Washington Carbon Intensity Standard (gCO2e per MJ) | Percent Reduction |
| 2025 | 98.11 | 2% |
| 2026 | 93.10 | 7% |
| 2027 | 89.10 | 11% |
| 2028-2037 | To be established in future rule making | 3% to 4% per year |
| 2038 | 55.06 | 45% |
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Alternative Jet Fuel and Marine Fuel
Ecology clarified that alternative jet fuel (AJF) produced from typical renewable feedstocks (e.g., plant oils, UCO, etc.) via hydrotreating processes will now be considered a Tier 1 fuel pathway, expediting the certification process. In addition to AJF, the program was amended to include alternative marine fuel as an “opt-in” fuel in an effort to promote decarbonization in the marine sector. The new amendments will also allow the use of utility-specific carbon intensities for electrolysis process energy through the end of 2037 provided certain requirements are met.
Regulatory revisions were also made to expand the criteria that must be met for fuel pathways using biomethane from dairy cattle or swine manure digestion to generate avoided methane credits. For facilities breaking ground between 2023 to 2029, avoided methane credits can be claimed for a maximum of 20 years. For facilities breaking ground in 2030 and later, renewable natural gas fuel pathways will be eligible for avoided methane credits through 2040. Hydrogen, electricity, renewable diesel, AJF and alternative marine fuel pathways using biomethane will be eligible for avoided methane credits through 2045 for facilities breaking ground in 2030 and later.
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Book and Claim Accounting
The amendments now allow for book and claim accounting for pipeline-injected biomethane to be used for AJF, alternative marine fuel and renewable diesel production, provided specific biomethane sourcing requirements are met.
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Verified Operational CI vs Certified CI
The latest amendments also mirror deficit obligation and credit true-up provisions recently adopted in California. If a verified operational CI is greater than the certified CI, excess credits generated due to the CI difference will be removed from the WFRS accounts of associated fuel reporting entities. Beginning with the 2026 reporting year, CI exceedance will result in deficit generation equal to four times the difference between the verified operational CI and the reported CI. Deficits will not be generated if the CI difference is due to GREET model updates. Credit true-ups will be introduced beginning with the 2025 annual fuel pathway reporting year. Credits representative of the difference between the reported CI and the verified operational CI will be placed in the account of associated fuel reporting entities after September 15th of the year following the compliance period.
Third party verification will now be required beginning in 2028 for 2027 fuel quarterly transactions data and 2026 and 2027 fuel pathway operational data. The third-party verification process outlined in the regulation emulates the procedures included as part of clean fuel programs in Oregon and Washington. Verification statements for fuel transactions reports and fuel pathways will be due on September 15th of the following year.
If you require assistance with Clean Fuels Program compliance or understand how the regulatory amendments impact your operations, please contact either Alex Marcucci, Amanda Barnett, or Trinity’s Seattle office for more info.
