The U.S. Environmental Protection Agency has issued a waiver to the California Air Resources Board allowing the state to implement and enforce its Omnibus low-NOx emissions regulation for heavy-duty vehicles and engines, a decision criticized by the American Trucking Associations.

Under the Clean Air Act, since 1967, California has been allowed to adopt emissions requirements independent from EPA’s regulations to meet its significant air quality challenges. But the state must get a waiver from the agency in order to do so. 

Other states have the option to adopt California’s more stringent emissions rules.

The Omnibus regulation will require manufacturers to comply with more stringent emissions standards. It will cut heavy-duty NOx emissions by 90%, overhaul engine testing procedures, and further extend engine warranties, according to the EPA.

CARB said its Low-NOx standards will protect communities from dangerous NOx pollution, which mixes in the atmosphere to form ground-level ozone, commonly called smog.

Nine other states — Colorado, Massachusetts, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont, and Washington — also have adopted CARB’s Heavy-Duty Low NOx Omnibus Standards, according to the Environmental Defense Fund.

EPA also granted California a waiver for its Advanced Clean Cars II (ACCII) rule, allowing the state to fully implement its regulation that would move the state toward 100% sales of zero emission options by 2035.

The agency, in its announcement of the waiver, said that it reviewed information from California and comments submitted by the public.

“Applying the limited criteria for waiver review under the Clean Air Act, EPA determined that opponents of the waivers did not meet their burden to show how the program is inconsistent with the Clean Air Act.”

ATA: ‘Waiver Will Be Short-Lived’

The American Trucking Associations slammed the decision in a statement, predicting that the incoming administration would reverse the move:

“This ill-advised waiver will be short-lived,” said ATA President and CEO Chris Spear.

“We look forward to the incoming administration and soon-to-be EPA Administrator Lee Zeldin reversing these misguided policies and restoring common sense to the nation’s environmental policy.

“California’s mandates have already created significant truck shortages and price increases, needlessly limiting truck sales and purchases in California. These policies are divorced from reality, disregard the operational needs of the trucking industry, and will have adverse consequences for consumers in the price they pay for everyday goods," Spear said.

The Owner-Operator Independent Drivers Association also said it looked forward to "working with the Trump administration's EPA in good faith towards achievable environmental outcomes.”

“The Omnibus Low-NOx waiver for California calls into question the policymaking process under the Biden administration's EPA," said OOIDA President Todd Spencer in a statement.

"Purposefully injecting uncertainty into a $588 billion American industry is bad for our economy and makes no meaningful progress towards purported environmental goals. 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."

Previous Challenges to CARB's NOx Rules

In 2022, the Truck and Engine Manufacturers Association filed suit challenging the NOx rules, contending that the narrow two-year window given to comply violated the requirements for California's emissions exemption. 

However, after facing criticism and being perceived as anti-clean-air, the association withdrew its suit.

The following year, CARB announced a "historic and unprecedented agreement" with EMA and major truck and engine makers to provide flexibility for truck and engine makers in meeting the state’s emissions standards, creating the Clean Truck Partnership.

Opposition to California's Electric-Vehicle Mandates

Meanwhile, California continues to move forward with its Advanced Clean Trucks and Advanced Clean Fleets rules, which are separate from the low-NOx standard.

Trucking organizations from eight states recently wrote letters asking their governors to delay implementation of the electric-truck regulations. 

In a letter to the governors of Colorado, Massachusetts, New Jersey, New Mexico, New York, Oregon, Rhode Island, and Washington, state trucking associations asked them to delay implementation of Advanced Clean Trucks (ACT) rules, which are set to take effect at the beginning of 2025 and 2027. 

“In New Jersey, important legislation to delay the EV truck regulations by two years passed the Assembly Transportation Committee last week,” said Eric DeGesero, lobbyist for the New Jersey Motor Truck Association. 

“We simply do not have the infrastructure in place for such a dramatic change in our trucking and logistics systems, and seven other states are in a similar position. If the ACT regulations are not delayed, we will see a disastrous impact on our American economy that will result in higher prices, job losses, and shipping delays across the country.”

Constitutional Question on EPA Clean Air Act Waivers

In addition, the U.S. Supreme Court last week declined to weigh in on the constitutionality of California’s ability to set more stringent emissions standards

The court said it would not review challenges to California’s authority to enforce its own pollution limits for new cars and passenger trucks. The court did say it would review a narrow question regarding whether the petitioners had standing to bring their claims, leading to contradictory headlines in the media.

The case was about California’s Advanced Clean Cars regulations, but a decision would likely also have affected challenges to the state’s Advanced Clean Trucks and Advanced Clean Fleets rules.