Noemí Bueno’s daughter was barely 14 months old when she started struggling to breathe.

Bueno, a San Bernardino resident who works as a crossing guard for a local school, remembers taking her baby girl to hospital after hospital, desperate for answers, before a doctor finally offered a diagnosis: asthma.

Bueno’s baby stayed in the hospital for four days, but even when she returned home her asthma kept her inside. “As she took a few steps, she felt like she was drowning again and I had to hug her and keep her from walking,” Bueno told CalMatters in Spanish. “As soon as she felt the air outside, the symptoms would begin again — and I feared she’d return to the hospital.”

Bueno was right to be worried: Air pollution is known to trigger asthma attacks, and has been linked to heart attacks, stroke, and cognitive problems. Much of Southern California — San Bernardino included — consistently struggles with smog and particle pollution. And Latino, Black, Asian American, and lower-income Californians bear the brunt of poor air quality.

The biggest contributors to pockets of unhealthy air across the state are the planes, trains, trucks and ships that move goods around, according to the California Air Resources Board. Heavy-duty trucks spew out 25 percent of diesel particulate pollution statewide, and produce about 8 percent of the state’s total greenhouse gases.

To tackle that tailpipe pollution, California’s clean air enforcers have proposed a rule that calls for major truck manufacturers to sell zero-emission vehicles in the state. Called the Advanced Clean Trucks regulation, it also asks major corporations and government agencies to report information about how they use their trucks — laying the groundwork for future rules to drive business toward clean truck companies.

It’s a controversial proposal that faces criticism from all sides. Environmental groups and a handful of legislators say the rule doesn’t push manufacturers hard enough to put more battery or fuel-cell electric trucks on the road; manufacturers say the rule could force them to supply trucks that fleet owners aren’t ready to buy.

On Thursday, the air board is expected to weigh those concerns and decide to either revise the rule, or push it to a mid-2020 vote. “This meeting will really set the tone for what the standard will actually look like,” said Jimmy O’Dea, senior vehicles analyst with the Union of Concerned Scientists, a science advocacy organization.

Sales requirements for certain vehicles, like zero-emission vans and semitrucks that haul trailers, will start at 3 percent in 2024 and rise to 15 percent in 2030. Other vehicles, like delivery or garbage trucks, will start at 7 percent, and climb to 50 percent by 2030.

Companies that manufacture clean trucks will be able to sell credits to conventional truck makers that can’t or won’t invest in developing zero-emission vehicles.

Once the rule is finalized, the air board will need to apply to the U.S. Environmental Protection Agency for special permission to enforce it. And right now, California and the EPA are battling over the latter’s decision to revoke California’s authority to run a similar sales requirement for clean passenger vehicles.

Still, Tony Brasil, chief of the air board’s Transportation and Clean Technology Branch, isn’t worrying about that yet; by the time the Advanced Clean Trucks proposal clears California’s regulatory hurdles and is ready for EPA approval, the 2020 presidential election will be over. “We won’t know what the administration may look like at that point, either,” Brasil said.

Plus, he said, the proposal is key for meeting federal air pollution targets. As written, a Union of Concerned Scientists analysis estimates the rule could put 75,000 clean trucks on the road by 2030 — or about 4 percent of the state’s trucks.

Brasil confirmed the number is in the same ballpark as the air board’s. That’s not enough, according to Katherine Garcia, communications associate for Sierra Club California. “We’re really seeing this as a historic moment for California to significantly reduce toxic air pollution,” she said.

“This really is about public health. People who live near a port, near a freeway, near a warehouse district — these folks are getting hit by toxic diesel pollution every day.”

And with both national population and international trade through the ports of Los Angeles and Long Beach projected to grow, the Southern California Association of Governments expects truck traffic to increase, too. A key freight corridor in southern California that saw 16,000 trucks daily in 2016 could see 25,000 or 30,000 daily by 2045, according to SCAG data shared with CalMatters.

Map courtesy of the Southern California Association of Governments.

That means tailpipe pollution will increase. So a coalition of environmental advocacy groups, including Sierra Club California, the Natural Resources Defense Council, and the Union of Concerned Scientists, are calling for a tougher rule that would boost the number of clean trucks on the road to 15 percent by 2030.

A handful of California legislators have joined the call for a tougher rule. At the end of November, Democratic assemblymembers Eloise Gómez Reyes, Phil Ting, Luz Rivas, and Marc Berman joined Democratic senators Ben Allen and Bob Wieckowski in a letter to air board chair Mary Nichols that said the proposed rule “falls woefully short of an impactful goal.”

In their letter, the lawmakers said: “Improving local air quality and reducing California’s contribution to global warming will require more than 4 percent of trucks to be zero-emission by 2030.”

Manufacturers are pushing against the air board’s proposal from the opposite direction. “We have no opposition to being able to supply the trucks,” said Tim Blubaugh, executive vice president at the Truck and Engine Manufacturers Association. “What we’re concerned with is having a ready buyer for those trucks.”

In a letter sent just days before the Thursday hearing, Blubaugh lays out the trade association’s concerns that the proposal “would put the cart before the horse” by setting a sales requirement “without first ensuring that the requisite [zero-emission vehicle] recharging infrastructure and [zero-emission vehicle] purchasing requirements will be in place.” His association pushed for financial incentives to help subsidize the costs of zero-emission trucks and the installation of charging infrastructure.

The California Air Resources Board does have a program called the Hybrid and Zero-Emission Truck and Bus Voucher Incentive Project, which provides discounts to clean vehicle buyers; the trouble is that money for the 2019-2020 fiscal year already is spent. Blubaugh said that means companies can’t plan on the subsidy long-term to reshape their truck fleets.

The air board’s Brasil, however, argues that the popularity of the discount program signals demand for clean trucks. Brasil also disagrees with the criticism that the proposed targets aren’t tough enough on manufacturers. “We think that they’re a good start,” he said.

The Advanced Clean Trucks proposal will join a collection of programs aimed at curbing emissions from trucks and buses. One air board rule already requires zero-emission transit buses by 2040 and another calls for zero-emission airport shuttle buses by 2035. “We’re focused on where can we get zero-emission trucks, as many as possible, where it makes sense,” Brasil said.

Other states will be watching the air board’s decision on Thursday. A coalition of air pollution control agencies from Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island, and Vermont wrote to the Air Resources Board to push for the higher 15 percent target.

A strong rule in California, the East Coast coalition said, would help drive the clean trucks market and lead the way for other states. “Our states, and the entire nation, have benefitted from California’s exceptional leadership in putting us on the path to a zero-emission transportation sector,” the letter said.

Legislators are paying attention, too. “The hope had been that the air board would provide the leadership necessary,” said San Francisco Democratic Assemblymember Phil Ting. “But obviously if they aren’t able to then we’ll definitely consider legislative action.”

Some 437 miles south of the air board’s hearing in Sacramento, San Bernardino’s Noemi Bueno is ready for change. The daughter she rushed from hospital to hospital is now 14 years old, and her second daughter is 12. Both are runners, and both have asthma. Bueno watches their races with their inhalers in her bag — just in case.

She said she knows trucks are necessary to transport food, or important packages. “I understand that,” she said. “But I wish there was a change, that they didn’t use diesel, that there were machines that don’t pollute.”

One of her daughters wants to be a P.E. teacher one day — a job that Bueno knows will require being outside. “I’d like the environment to improve, the pollution to diminish, so that my daughter’s dreams aren’t cut short,” she said.

Jackie Botts contributed to this reporting, and translated the conversations with Noemí Bueno.

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