Chapter 173-423 WAC – Clean Vehicles Program

Ecology is considering amendments to Chapter 173-423 WAC, Washington’s 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. These regulations ensure that new motor vehicles sold in Washington pollute less, and they are an essential policy tool for addressing climate change and improving air quality – particularly in communities overburdened by vehicle emissions.

In this rulemaking, Ecology is considering amendments to Washington regulations that will track amendments to the following California regulations: Advanced Clean Cars, Advanced Clean Cars II, Advanced Clean Trucks, and Heavy-Duty Low NOx Omnibus standards.

Additionally, Ecology is considering adopting components of California’s Truck and Bus regulation to maintain consistency with RCW 70A.30.010, particularly in light of ongoing federal attempts to revoke California’s waivers for the current medium- and heavy-duty low-emission vehicle standards (i.e., Heavy-Duty Low NOx Omnibus). Although Ecology holds these recent federal waiver actions as unlawful, this ensures the cleanest available standards are implemented in Washington.

The relevant sections that Ecology is considering adopting by reference from the California Code of Regulations are listed below.

Revising Existing Sections:

•  California Code of Regulations, Title 13
  • 1900, 1956.8, 1961.2, 1961.3, 1962.2, 1962.3, 1963.1, 1963.2, 2963.3, 1963.4, 1963.5, 1965, 1968.2, 1968.5, 1969, 1971.1, 1971.5, 1976, 1978, 2035-2040, 2111 – 2119, 2121 – 2131, 2137 – 2149, 2166, 2166.1, 2167, 2168, 2169, 2169.1- 2169.8, 2170, 2423, 2485
• California Code of Regulations, Title 17
  • 95300 – 95307, 95311, 95660 - 95663

New Sections:

•  California Code of Regulations, Title 13
  • 1900.0.1, 1956.8.1, 1956.8.2, 1961.2.1, 1962.2.1, 2962.3.1, 1963.6, 1963.7, 1965.0.1, 1968.2.1, 1968.5.1, 1969.0.1, 1971.1.1, 1971.5.1, 1976.0.1, 1978.0.1, 2035.0.1 -2040.0.1, 2111.0.1- 2119.0.1, 2121.0.1, 2123.0.1, 2125.0.1- 2131.0.1, 2137.0.1, 2139.0.1 – 2149.0.1, 2317.0.1, 2423.0.1, 2485.0.1, 2903, 2903.0.1
• California Code of Regulations, Title 17
  •  95300.0.1-95312.0.1, 95308-95312, 95660.0.1-95664.0.1, 95664

Furthermore, amendments under consideration include any changes to components of these regulations in Chapter 173-423 WAC that are needed to address Washington-specific vehicle market conditions. These changes must be limited to aspects that do not create a “third vehicle” for regulatory purposes outside of those created for the California and federal markets, as is required by the federal Clean Air Act. Ecology is also evaluating additional fleet reporting requirements, beyond the one-time report required in 2023, to authorize additional data collection. These amendments are important to streamline program implementation, provide additional compliance flexibility and clarity, maintain consistency with other states and the federal government, and work toward meeting Washington’s goals for greenhouse gas emissions.