CARB issues new omnibus rules to crack down on NOx from trucks

The California Air Resources Board on Thursday passed new regulations that will further tighten emission restrictions on heavy-duty trucks in the state.

The new rule – called the Low NOx Heavy-Duty Omnibus Regulation – will cut NOx emission limits on heavy-duty trucks by 75% below existing standards by 2024. That number jumps to 90% in 2027. The rules will be applied to trucks with model year engines beginning in 2024.

“Even as California ramps up the numbers of zero-emission electric and fuel-cell trucks on our roads over the next decade and beyond, tens of thousands of new internal combustion trucks will still be sold in our state,” CARB Chair Mary D. Nichols said in a statement Friday. “This regulation ensures that conventional diesel trucks will run as cleanly as possible at every point in their duty cycle. It takes a significant bite out of smog-forming pollution in every region in the state, and will make a major contribution to cleaning the air in communities close to ports, railyards and distribution centers that are now most heavily impacted by pollution from heavy truck traffic.”

CARB claims the reduction in NOx emissions would be equivalent to removing 16 million cars from the road by the time the regulation has become fully implemented in 2031.

The Truck and Engine Manufacturers Association filed comments in opposition to the rulemaking. The group says CARB’s rules “are cost-prohibitive, infeasible, unenforceable and illegal,” and that the measures “fall well short of any reasonable cost-benefit metrics.”

“CARB has grossly underestimated the costs associated with nearly all aspects of the proposed far-reaching Omnibus Regulations, and has materially overestimated their potential benefits,” the comments state.

In June, CARB passed its Advanced Truck Regulations, establishing the nation’s strictest emissions standards for manufacturers. The new regulation requires truck manufacturers to increase the percentage of their zero-emission truck sales beginning in 2024. By 2035, 75% of Class 4 through 8 truck sales and 40 percent of truck tractor sales must come from zero-emission truck and chassis sales.

The board also on Thursday approved a new rule for ocean-going vessels docked at California ports. That rule adds new vessel categories to the existing rules including auto carriers and tankers. It sets strict limits on the use of auxiliary engines and auxiliary boilers while the ships are docked. The existing rule will be replaced with the new, expanded rule in 2023.