Southern California air officials voted overwhelmingly Friday to give themselves the power to levy fines on the ports of Los Angeles and Long Beach if they don’t fulfill their promises to transition to cleaner equipment.

The ports remain the largest source of smog-forming pollution in Southern California — releasing more emissions than the region’s 6 million cars each day.

The South Coast Air Quality Management District’s governing board voted 9-1 in favor of an agreement that commits the ports to installing zero-emission equipment, such as electric truck chargers or hydrogen fuel pumps, to curb air pollution from the heaviest polluters. The plans will be submitted in three phases: heavy-duty trucks and most cargo-moving equipment by 2028; smaller locomotives and harbor crafts by 2029; and cargo ships and other large vessels by 2030.

If the ports don’t meet their deadlines, they would be fined $50,000 to $200,000, which would go into a clean-air fund to aid communities affected by port pollution. The AQMD, for its part, forgoes imposing new rules on the ports for five years.

Many environmental advocates voiced disappointment, saying the agreement doesn’t contain specific pollution reduction requirements.

“I urge you not to sign away the opportunity to do more to help address the region’s air pollution crisis in exchange for a pinky promise,” said Kathy Ramirez, one of dozens of speakers at Friday’s board meeting. “This is about our lives. I would encourage you to think about why you joined the AQMD board. If not for clean air, then for what?”

Port officials and shipping industry officials lauded the decision as a pragmatic way to transition to a zero-emissions economy.

“The give and take of ideas and compromises in this process — it mirrors exactly what a real-world transition to zero emissions looks like,” said William Bartelson, an executive at the Pacific Maritime Assn. “It’s practical, it’s inclusive and it’s grounded in shared goals.”

The vote answers a long-standing question over how the AQMD intends to reduce pollution from the sprawling trade complex, a focus of environmental justice efforts for decades.

The twin ports of Los Angeles and Long Beach, known as the San Pedro Port Complex, is the largest container port in the Western Hemisphere, handling 40% of all container cargo entering the United States. Despite years of efforts at reducing pollution, the vast majority of heavy machinery, big rigs, trains and ships that serve the region’s bustling goods movement still are powered by diesel engines that emit toxic particles and nitrogen oxides, a precursor to smog.

For nearly a decade the AQMD has vacillated between strict regulation and a pact with the ports with more flexibility. Several negotiations over a memorandum of understanding failed between 2017 and 2022. The board was prepared to require the ports to offset smog-forming pollution from trucks, trains and ships through clean air projects, like solar panels or electric vehicle chargers. Instead, the ports presented the AQMD with a proposed cooperative agreement, prompting the agency to pause its rulemaking.

The AQMD doubled the penalties in that proposal and agreed not to make new rules for five years, not the 10 the industry wanted.

Perhaps the most important details of the agreement — the types of energy or fuel used; the appropriate number of chargers or fueling stations — won’t be published for years. The lack of specifics prompted skepticism from many environmental advocates.

“It’s just a stall tactic to make a plan for a plan in the hope that emission reductions will come sometime in the future,” said Fernando Gaytan, a senior attorney with environmental nonprofit Earthjustice.

The contract also includes a clause that the AQMD or ports could terminate the agreement “for any reason” with a 45-day written notice. Wayne Nastri, the AQMD’s executive officer, said this gives the agency the option to switch back to requiring zero-emission infrastructure at the ports.

“If we report back to you and you’re not seeing the progress being made, you can be confident knowing that you can pivot and release that [rulemaking] package,” Nastri said to the board.

At the end of public comment, opponents of the agreement broke into loud chants. The AQMD cleared the gallery as the board discussed the proposal.

Board member Veronica Padilla-Campos, the lone “no” vote, said the agreement lacked the necessary emission reductions and offered “no clear accountability” to local communities.

Fellow board member Nithya Raman acknowledged many criticisms of the agreement but ultimately voted for it.

“I really have come to believe that the choice before us is this cooperative agreement or no action at all on this issue — continuing a decade of inaction,” Raman said.

“I will be voting to support it today, because I do think that it is our only pathway to take any steps forward toward cleaner air at the single largest source of air pollution in the region.”

The plan still must be approved by commissioners at the Port of Los Angeles and the Port of Long Beach Harbor Commission at meetings this year.