Gov. Gavin Newsom on Sept. 22, 2022 vetoed AB 2550 which would have required the California Air Resources Board to bypass the Valley air district in areas where Valley regulators have failed to meet clean air standards on time. Credit: John Walker / The Fresno Bee

What's at stake?

The valley routinely has the worst air quality in the nation - specifically for small particles, known as PM 2.5. Without EPA's approval of the air district plan, more regulations could be coming.

Members of the governing board of the San Joaquin Valley Air Pollution Control District expressed frustration about the recent disapproval of its 2018 PM2.5 plan by the EPA during its most recent meetingmeeting on Thursday​.

In November, the EPA disapproved the air district’s evidence that the San Joaquin Valley was in attainment of the 1997 annual PM2.5 National Air Quality Standard by January 2021. The EPA found that the central details of the 2018 plan, including air monitoring data and a 5% emissions reduction forecast, were insufficient to achieve the 1997 standard.

The San Joaquin Valley remains the only air basin in the United States that has not met the 1997 rule, which requires an annual PM2.5 concentration below 15 micrograms per cubic meter for three consecutive years. PM2.5 particles are a type of air pollution that are linked to premature death, Alzheimer’s and autism.

Jessica Fierro, director of air quality planning at the Air District, said that remediating the recent federal disapproval will be “extremely challenging.”

“We are already implementing the most stringent stationary and mobile source emissions requirements,” Fierro said.

One of the EPA’s judgments was that the air district’s forecasted reduction in nitric oxide emissions was not enough to meet the 1997 rule. The 2018 plan relied heavily on homeowner incentives to replace residential fireplaces with gas-powered heating appliances.

The disapproval means that the Air District will have to pursue more measures to rein in pollution in the Valley in the coming months.

Air quality advocates at the Thursday meeting said that the Air District’s failures stem from its “pay-to-pollute” schemes that have expanded oil and gas extraction in the Valley.

“The Valley Air District is a captured agency that has failed my community and caused irreversible harm to the health of generations of Valley residents,” said Jasmin Martinez, coordinator at the Central Valley Air Quality Coalition.

“Valley residents have urged the district to take more aggressive actions, such as removing exemptions, closing loopholes and requiring direct [pollution] reductions instead of credits,” she said. “But we continue to see lenient rules and exemptions favoring the [oil and gas] industry.”

Fierro said that the EPA’s verdict puts the district’s technology-first ethos for coming into compliance with the 1997 rule at an impasse.

“(Additional reductions are) really not feasible for most control technologies,” she said. “This is a significant issue for our region. There’s simply a scarcity of measures.”

Fierro said that meeting the federal clean air mandate will require “significant analysis, a lot of innovation, [community] outreach and a lot of inter-agency coordination” and called on the California Air Resources Board and the EPA to provide more guidance on what to do next.

Buddy Mendes, Air District board member and Governing Board ex-chair, said there was only so much that could be done to improve Valley air, citing a 150-year-old account that the San Joaquin Valley was already “a smoky, mosquito-infested hell” even before industrialized agriculture.

Air District Calls On EPA To Reduce Valley Ozone

The board also discussed a new ozone pollution plan and renewed the agency’s clean-tech tractor replacement program.

Fierro updated the governing board on the agency’s ongoing efforts to create a new ozone-reduction plan. She presented a graph showing that half-a-decade of smog progress in the Valley has been wiped away by the rapidly escalating severity of California’s wildfire season.

Fierro said that the EPA needs to strengthen federal regulation on interstate trucks, planes, and trains to amend these new air quality deficits. “California needs the EPA’s help,” she said, adding that after years of stagnation in interstate truck and plane regulation, federally regulated pollution sources are now more prolific Nitric Oxide polluters than state-regulated sources.

Fierro said that it is hopeful that the EPA’s Southwest office, led by Martha Guzman, is addressing these concerns via a Clean Truck Rule published last month.

“This (rule) will absolutely help the Valley because of the interstate trucks that are traveling through our region,” she said.

Clean Tractor Program extended

The Air District governing board voted to accept $168 million in state funds this year to extend its program to replace tractor engines across the San Joaquin Valley. The program, which has in the last four years spent $569 million to upgrade 6,200 tractors in the Valley, covers a fraction of the costs for growers to upgrade their tractor engines to higher-efficiency, less-polluting technology.

An agricultural representative at the meeting said that to meet state deadlines for air pollution, an additional 3,000 tractors would need to be outfitted with clean tech in the next 21 months.

The new funding comes at a time when clean-tech tractor conversion rates in the Valley have declined 50% over the last six months. An air district representative said the decline is likely due to rising equipment costs from supply-chain shortages.

To boost farmer demand for the tractor incentive program, the Air District proposed to increase the tractor incentives by 50% with the new batch of state funds. This upgrade would cover 50-60% of the clean-tech upgrade costs, up 30-40% from what it is now.

The representative hoped the changes would help bring the number of applications back up. “With these changes, we expect to see a significant increase in the number of applications,” he said.

The air district also upgraded its clean tractor program for Valley growers with farms less than 100 acres. The program will now cover up to 80% of the small farmer’s cost to purchase certified pre-owned, high-efficiency tractors.

Will Scott Jr. drew a rare laugh from the crowd during his comments on behalf of the small-farmer program. Scott Jr. said despite the tractor trade-in program being a “godsend” for his modest farm, sending his old tractor to the crusher gave him a bit of heartache.

“That hurt me. That old equipment may not be perfectly functioning, but you have a relationship with it. You go out there everyday and if you cross your fingers enough, it starts up.”

Gregory Weaver is a freelance journalist based in California’s central San Joaquin Valley. He can be reached at

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Gregory Weaver is a staff writer for Fresnoland who covers the environment, air quality, and development.