The Environmental Protection Agency (EPA) approved two Clean Air Act waiver requests today, December 18, from the California Air Resources Board (CARB) that paves the way for the Golden State to implement and enforce the Advanced Clean Cars II (ACC II) regulations, which is specifically for light-duty vehicles, and the "Omnibus" low NOx regulation aimed at heavy-duty vehicles.
The Omnibus Low-NOx reg drastically cuts NOx and particulate matter emissions standards and includes new requirements for test procedures, regulatory useful life, and emissions warranties. The rule built upon the EPA's own heavy-duty NOx regulation, which was finalized in 2022 for model year 2027 and beyond.
The ACC II requirements take effect for the 2026 model year.
For context, California received congressional approval 50 years ago to adopt environmental standards that are stricter than the federal government's regulations due to its issues with air quality. Once the EPA grants California the required waiver(s), other states are allowed to adopt those same regulations. While this is good for states who place an emphasis on environmental issues, the policy also creates inconsistency between states, making it harder (and more expensive) for fleets to do business.
The ACC II and Omnibus regulations are not to be mistaken with CARB's Advanced Clean Fleets (ACF) rule which, if implemented, will require any new truck being registered to operate in any California port to be a zero-emissions vehicle (ZEV). Additionally, the ACF would set a 2036 deadline on the manufacture and sale of medium- and heavy-duty diesel-powered trucks. In other words, a complete ban on the sale of diesels in less than a dozen years from now. The EPA has not yet granted the ACF waiver but is widely expected to do so before the second Trump administration takes power.
[Related: California's aggressive ZEV mandate backfiring at ports?]
During the ACC II waiver review process, the EPA found that opponents of the waivers - most of whom came from the transportation industry - "did not meet their burden to show how either program is inconsistent with the Clean Air Act."
According to CARB projections, the low NOx standards will provide protection for communities at higher risk of NOx pollution that mixes in the atmosphere to form smog. Smog is a known contributor to serious health issues including asthma and other related respiratory illnesses.
“California’s ongoing success in tackling pollution challenges and improving public health is possible thanks to landmark regulations that support technological innovation and move us toward a zero-emissions future for transportation,” said CARB Chair Liane Randolph. “Consumers and fleets are increasingly making the choice to drive clean vehicles, and today’s waiver approvals will further that progress.”
[Related: California regulators approve stricter rules for low carbon fuels]
Trucking, meanwhile, is less than thrilled with the EPA's waiver.
“The Omnibus Low-NOx waiver for California calls into question the policymaking process under the Biden administration's EPA. Purposefully injecting uncertainty into a $500 billion American industry is bad for our economy and makes no meaningful progress towards purported environmental goals," says Todd Spencer, president of the Owner-Operator Independent Driver's Association (OOIDA) in a statement to Clean Trucking. "EPA's credibility outside of radical environmental circles would have been better served by working with regulated industries rather than ramming through last-minute special interest favors. We look forward to working with the Trump administration's EPA in good faith towards achievable environmental outcomes.”
[Related: Trump's Energy Secretary nominee, Chris Wright, is a fossil fuel 'pragmatist']
