California Air Resources Board Drops Bid to Enforce Advanced Clean Fleets Rule

Withdrawal of request for EPA waiver means the state no longer seeks to enforce its zero emission vehicle mandate on fleets.

The California Air Resources Board (CARB) has withdrawn its request for an EPA waiver to enforce its Advanced Clean Fleets (ACF) rule. The withdrawal means CARB is now no longer seeking to enforce its zero emissions vehicle mandate on fleets.

CARB withdrew its waiver request as part of its preparation for a drawn-out struggle with the incoming Trump Administration. During his presidential campaign, Donald Trump spoke out against such mandates.

Background
Under the Clean Air Act, California has the unique freedom to set its own emissions standards that exceed EPA's. However, CARB needs a waiver from EPA before it can enforce the regulations.

The ACF is a controversial zero-emission vehicle mandate directly targeting fleets. The regulation requires certain fleets to phase-in zero-emission vehicles and, by 2036, requires manufacturers to only manufacture zero-emission trucks.

On Dec. 18, 2024, the EPA granted California the waiver for CARB’s Advanced Clean Cars II (ACC2) regulation, which will require an increasing number of new light-duty vehicles sold to be zero-emission vehicles, all of them by 2035.

The HD Omnibus (low NOx combustion) waiver request was granted simultaneously.

The Omnibus regulation will cut heavy-duty NOx by 90% and extend the warranty for emissions equipment. Numerous other states have adopted the California Omnibus regulation, including Colorado, Massachusetts, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont and Washington.

The Advanced Clean Trucks (ACT) is still in effect and calls for OEMs to sell increasing percentages of zero-direct-emission trucks through model year 2035. In those states with an effective date of 2025, 7% of new truck sales must be zero-emission trucks beginning Jan. 1, 2025.

Other states have adopted the ACT regulations, which the EPA allows if the states do not alter the rule in any manner.

The ACF and ACT rules were always meant to work together. The ACT would force OEMs to build ZEVs, and the ACF would force fleets to buy them. Each rule needed an EPA waiver as it exceeded federal emissions regulations. The ACT waiver was previously granted.

Source: Contractor Magazine / ARB Withdraw Notice