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Washington’s Second Substitute House Bill 1409 Forges Stronger Carbon Intensity Targets, Clearer Rules, and Greater Transparency

Washington’s Second Substitute House Bill 1409 Forges Stronger Carbon Intensity Targets, Clearer Rules, and Greater Transparency

Key takeaways

Washington’s new clean fuels law raises the state’s carbon intensity (CI) reduction target for transportation fuels from the previous 20% by 2038 to 45% by 2038, with the option to revise 2038 targets to 55% if, by 2032 certain climate benchmarks are not met.

Progress on emissions targets hinges on timely permitting and construction of major biofuel facilities. Without these, the state cannot legally tighten standards beyond 10% after 2028 or 20% after 2030, making infrastructure development critical.

Non-compliance triggers steep penalties: up to $10,000 daily, $25,000 monthly for unregistered operations, and fines up to four times the value of missed credits—establishing one of the toughest enforcement regimes among U.S. clean fuels programs.

The law mandates Washington to align its clean fuel rules with neighboring states, reducing regulatory friction and supporting a cohesive West Coast clean fuels market.

Washington’s Department of Ecology must distinctly report the public health benefits of the Clean Fuels Program separately from other vehicle emission standards—unlike Oregon and California, where these benefits are combined—enhancing transparency on each policy’s specific impact.

On 17^th May 2025, Washington State updated its clean fuels policy with the passage of Second Substitute House Bill 1409 in 2025. This new law not only raises the bar for carbon intensity (CI) reduction but also introduces a sophisticated framework for compliance, enforcement, and transparency. Here’s an in-depth analysis of how the new regime compares to the previous system, what’s truly different, and what it means for the future of clean fuels in Washington.

Washington’s Updated Clean Fuels Law: Stronger Carbon Intensity Targets with Built-In Flexibility

Under Washington’s original clean fuels program, the goal was to reduce the carbon intensity of transportation fuels by 20% below 2017 levels by 2038, which was similar to targets set by California and Oregon and followed a gradual, incremental approach. With the passage of Second Substitute House Bill 1409 in 2025, the state’s ambitions have increased significantly. The new law requires a 45% reduction in CI by 2038, and it also gives the Department of Ecology the authority to raise this target to 55% by 2038 if, by 2032, either the state’s zero-emission vehicle rules are not being enforced or transportation fuel emissions have not declined in proportion to broader climate goals (as described in Section 1(5)(b)(i) of the bill). Additionally, Section 1(5)(b)(ii) allows the Department to temporarily relax annual targets by up to 2% if fuel supply forecasts suggest there could be shortages, providing a safeguard against unintended disruptions. These provisions mean that while the new law is much more ambitious, it also includes built-in flexibility to respond to real-world conditions and ensure the targets remain achievable.

Infrastructure as the Gatekeeper: Biofuel Facility Prerequisites

In Washington’s earlier clean fuels program, the state set targets for reducing the carbon intensity of transportation fuels but did not connect those targets to specific milestones in fuel production infrastructure. This meant that, in practice, the state could continue to tighten standards even if there wasn’t enough in-state capacity to produce low-carbon fuels. As a result, the pace of reductions was not directly tied to the state’s ability to build or expand biofuel production facilities, which could have led to challenges if supply did not keep up with regulatory demands.

With the passage of Second Substitute House Bill 1409, this approach has changed. Now, before the state can require reductions in carbon intensity beyond 10% after 2028, there must be at least one new or expanded biofuel facility in Washington capable of producing more than 60 million gallons per year, and there must be a 15% net increase in in-state biofuel production. Similarly, after 2030, no further tightening beyond 20% can occur unless at least one new or expanded facility has received the necessary permits after January 1, 2025. Additionally, any tightening of standards after 2030 requires a legislative audit and review. These requirements mean that progress on emissions targets is now directly linked to the state’s actual infrastructure and production capacity, helping to ensure that the clean fuels program remains practical and that fuel supply is not disrupted by overly ambitious targets.

Washington’s Second Substitute House Bill 1409 Forges Stronger Carbon Intensity Targets

Washington’s Clean Fuels Law Raises the Stakes for Non-Compliance

Under Washington’s earlier clean fuels program, the penalties for non-compliance were based on general air quality laws. The Department of Ecology could impose civil penalties of up to $10,000 per violation per day for failing to meet program requirements, such as not submitting reports or not retiring credits. However, these penalties were not tailored to specific types of violations within the clean fuels program, and the law did not provide additional or higher fines for particular infractions like operating without registration, misreporting, or improper use of credits. As a result, while the threat of penalties existed, the framework was relatively simple and less targeted, which may have limited its effectiveness as a deterrent for more complex or intentional violations.

The amended legislation introduces a much more comprehensive and stringent penalty regime. Now, the Department can issue up to $10,000 per day for late reporting, up to $25,000 per month for operating without proper registration, and penalties of up to four times the value of any missed credits for failing to meet credit retirement obligations. There are also specific fines of up to $1,000 per credit for misreporting or generating illegitimate credits, and up to four times the improperly spent credit revenue for electric utilities that misuse funds. Additionally, violations of third-party verification requirements can result in fines of up to $50,000 or $10,000 per day. This new structure is far more detailed and severe, targeting a wider range of potential violations and making it clear that non-compliance will carry significant financial consequences. The shift from a general penalty to a nuanced, violation-specific system is designed to strengthen enforcement and maintain the integrity of the clean fuels program.

Washington’s Approach to Regional Clean Fuels Harmonization

In Washington’s earlier clean fuels program, the idea of aligning with neighbouring states like California and Oregon was more of a guiding principle than a binding rule. The Department of Ecology was encouraged to consider the standards and practices of these states, but there was no legal requirement to match their regulatory details. This approach led to several practical issues for fuel suppliers and credit generators operating across state lines. For example, California’s Low Carbon Fuel Standard and Oregon’s Clean Fuels Program each have their own methods for calculating carbon intensity, unique reporting timelines, and different lists of eligible fuel pathways and credits. Without a mandate for harmonization, Washington’s rules sometimes diverged from those of its neighbours, forcing companies to track and comply with multiple sets of standards and procedures. For businesses, this patchwork of requirements translated into higher operational costs, delays in credit recognition, and potential lost revenue. In some cases, it could even discourage the introduction of innovative low-carbon fuels in Washington if those fuels were already approved and credited in California or Oregon but not yet recognized under Washington’s program. Such regulatory friction not only complicated life for fuel suppliers but also risked slowing the region’s overall progress toward shared climate goals.

The new clean fuels law, enacted as Second Substitute House Bill 1409 in 2025, takes a much stronger stance on regional alignment. The legislation explicitly requires the Washington Department of Ecology to “seek to adopt rules that are harmonized with the regulatory standards, exemptions, reporting obligations, rule updates, and other clean fuels program compliance requirements and methods for credit generation of other states that… have adopted low carbon fuel standards or similar greenhouse gas emissions requirements applicable specifically to transportation fuels” and that are significant trading partners with Washington. This means Washington is now legally committed to aligning not only its overall regulatory standards but also the details—such as exemptions, how credits are generated, how rules are updated, and how reporting is handled—with those of states like California and Oregon. However, Despite the new harmonization requirements in Washington’s Clean Fuels Standard (CFS) legislation—which direct the Department of Ecology to align its rules with those of other states—the stacking of credits is not permitted under the updated program. Each credit generated under the Washington CFS can only be used to satisfy compliance obligations within the state’s own program and cannot be double-counted or applied toward compliance in multiple regulatory regimes.

Distinguishing Public Health Benefits Attributable to Washington’s Clean Fuels Program

In the design of Washington’s prior clean fuels program, public health co-benefits—such as reductions in ambient concentrations of fine particulate matter (PM 2.5) and other conventional air pollutants—were reported in aggregate with benefits from other vehicle emission standards, notably those established under Chapter 70A.30 RCW (e.g., tailpipe emissions regulations). This aggregation approach, which was not explicitly separated in statutory language, limited the ability of policymakers and analysts to attribute observed improvements in air quality or health outcomes to the clean fuels program as distinct from other regulatory interventions. As a result, any quantitative assessment of the program’s incremental impact on public health was confounded by the inclusion of benefits from overlapping policies, reducing the precision of cost-benefit analyses and making policy-specific accountability more challenging.

The 2025 amendments, address this methodological gap by requiring the Department of Ecology to “distinguish between public health benefits from small particulate matter and other conventional pollutant reductions achieved primarily as a result of vehicle emission standards… and the incremental benefits to air pollution attributable to the program.” This statutory change enables a more accurate evaluation of the clean fuels program’s standalone effectiveness and supporting evidence-based policy refinement moving forward.

The table below offers a side-by-side overview of key differences between the previous and updated Washington Clean Fuels Standard (CFS) programs.