Subject of Possible Rule Making: The department of ecology (ecology) is considering amendments to chapter 173-423 WAC, the clean vehicles program rule. Washington law (RCW 70A.30.010) requires ecology to adopt certain California regulations to maintain consistency with California's emissions standards for new motor vehicles and engines. To date, ecology has delivered on this legislative requirement to adopt regulations consistent with the following California programs: Advanced clean cars, advanced clean cars II, advanced clean trucks, and heavy-duty low-NOx omnibus standards.

Ecology is currently considering amendments to Washington regulations that will track amendments to California's advanced clean trucks and heavy-duty low-NOx omnibus regulations currently adopted and/or under consideration by the California air resources board. These amendments are important to streamline program implementation, provide additional compliance flexibility, and maintain consistency with other states and the federal government. The advanced clean trucks regulations apply to medium- and heavy-duty engine and vehicle manufacturers and require zero-emission models to make up an increasing percentage of new vehicle sales in Washington, starting with engine model year 2025. The heavy-duty low-NOx omnibus regulation applies to heavy-duty internal combustion engine manufacturers and requires them to meet more protective air quality standards, particularly on oxides of nitrogen and particulate matter, starting in model year 2026.

Ecology is also inviting public input about additional California motor vehicle emissions standards the agency should consider adopting in a future rule making to comply with the requirements in chapter 70A.30 RCW and efficiently and cost-effectively reduce greenhouse gas emissions from transportation in line with Washington's greenhouse gas emissions reduction mandates in RCW 70A.45.020.

Reasons Why Rules on this Subject may be Needed and What They Might Accomplish: In accordance with chapter 70A.30 RCW, ecology is exploring amending these rules to maintain consistency with and implement California's motor vehicle emission standards. Amendments to both the heavy-duty low-NOx omnibus regulation and the advanced clean trucks regulation from California, as well as potential additional California motor vehicle emissions standards, are crucial to achieving Washington's greenhouse gas emissions reduction mandates in RCW 70A.45.020.

Other Federal and State Agencies that Regulate this Subject and the Process Coordinating the Rule with These Agencies: 42 U.S.C. Section 7507 (also known as Section 177 of the Clean Air Act) allows states to adopt and enforce California's vehicle emission standards instead of the federal ones if the state standards are identical to the California standards. The United States Environmental Protection Agency (EPA) regulates the subject at the federal level; ecology is awaiting decisions from EPA on a preemption waiver request that will impact this rule making. At the state level, ecology will be coordinating with the department of licensing to discuss implementation of the rule.

Interested parties can participate in the decision to adopt the new rule and formulation of the proposed rule before publication by contacting Nikki Harris, Department of Ecology, Climate Pollution Reduction Program, P.O. Box 47600, Olympia, WA 98504-7600, phone 360-764-6018, Washington relay service or TTY call 711 or 877-833-6341, email Nikki.harris@ecy.wa.gov, website https://ecology.wa.gov/regulations-permits/laws-rules-rulemaking/rulemaking/wac-173-423.

Additional comments: Interested parties can stay informed about the rule making and public involvement opportunities as described above. Ecology will extend an offer for government-to-government consultation with tribal governments during each phase of rule development.