Despite Burden, California Backs EPA’s PM Plan But Seeks Tougher Rules

Source: By Stuart Parker, Inside EPA • Posted: Tuesday, January 10, 2023

Despite the daunting compliance challenge California is expected to face from EPA’s plan to strengthen fine particle (PM2.5) limits, state officials are welcoming the agency’s proposal and even asking for stronger standards, though they are also pressing for stronger state and federal controls on mobile sources such as trucks and ships.

The California Air Resources Board (CARB) in a Jan. 6 statement says EPA should consider going even further than Administrator Michael Regan has proposed so far, by tightening the annual health-based national ambient air quality standard (NAAQS) for PM2.5 more than EPA suggests, and also by tightening a 24-hour health-based limit as well.

“We applaud this move by EPA toward stronger standards to protect public health, and we encourage further strengthening of EPA’s proposal,” CARB Executive Officer Steven Cliff said.

However, Cliff urges EPA to approve the state’s pending requests for waivers from Clean Air Act requirements to adopt tougher rules for mobile sources, and to issue stricter federal rules.

“In light of the fact that over half of mobile source emissions in California come primarily from federally regulated sources, such as locomotives, ships and airplanes, it is imperative that EPA expeditiously approve California’s waiver requests, and commit to do its part to reduce harmful emissions to mitigate the impacts of fine particulate pollution, especially on the low-income communities and people with greater economic and environmental challenges who bear the brunt of these impacts,” he adds.

California has several pending requests for waivers from federal mobile source rules before the agency, as the state seeks to exercise its unique air act powers to set limits tougher than federal standards.

Regan in his proposal unveiled Jan. 6 advocates tightening the current annual health-based, or “primary” PM2.5 standard down to a level between 9 micrograms per cubic meter (ug/3) and 10 ug/m3, tougher than the current annual limit of 12 ug/m3. Regan does not plan to also tighten the current daily primary limit of 35 ug/m3.

EPA’s own regulatory impacts analysis (RIA) shows that California counties will be disproportionately impacted by any tightening of the NAAQS, even under the least-stringent scenario considered by EPA. The RIA predicts that a range of available and cost-effective control options it considered will not be adequate to bring dozens of California counties into attainment with a new limit.

But despite such findings, CARB urges EPA to further strengthen the standards while also clamping down further on mobile sources. “Given scientific studies demonstrating health impacts down to the level of 8 micrograms, CARB encourages EPA to consider further strengthening of the proposal,” the air board says.

CARB “also urges EPA to consider strengthening the short-term or 24-hour standard. CARB has previously urged EPA to consider a short-term standard for fine particulate matter as low as 25 micrograms, to ensure the highest level of health protection.”

The California agency notes the substantial estimated health benefits that flow from reducing levels of PM2.5, and that low-income communities and communities of color are disproportionately affected by fine particle pollution. CARB estimates that lowering the current annual PM2.5 standard in the range of 8-10 ug/m3 could prevent 4,600 annual premature deaths in the state, 850 heart and lung disease hospitalizations, and 2,100 asthma emergency room visits.

“Research has shown that PM2.5 air pollution exposure is linked to a growing number of additional health problems, even at low concentrations, resulting in economic impacts, including lost workdays and school absences. Research also shows that PM2.5 disproportionately impacts people of color and low-income communities often located near ports, freeways or other sources of this harmful pollution, in both California and across the country,” CARB says.

Additional Measures

Therefore, additional measures to limit emissions will be required, especially for mobile sources that state regulators have limited abilities to control, CARB says.

If EPA grants California’s truck rule waiver requests, this would allow for tougher state limits on NOx from heavy-duty vehicles that other states could then adopt. California has adopted strict limits on NOx for new heavy-duty trucks, under its “omnibus” rule, and is driving a rapid electrification of its overall vehicle fleet that should reduce GHGs and slash NOx and PM2.5 emissions. The California truck NOx standards are tougher than new federal limits.

But more will be required on a national level if California is to attain NAAQS for PM2.5 and other pollutants such as NOx and ozone, for example, because so many trucks operating in the state are registered elsewhere, California officials have previously said. EPA has said it intends to decide in March whether to grant California’s waivers, and to also propose stronger federal GHG standards in March for heavy-duty vehicles, alongside new proposed GHG and other limits for light-duty vehicles.

Locomotives and international shipping emissions also fall under federal jurisdiction. California is forging ahead with proposed tougher locomotive rules, but EPA has so far only promised the state it will consider its options for tightening federal rules for the sector.

Substantial Strengthening

CARB’s call for a tougher PM NAAQS echoes that of major environmental and public health groups, which have said they are disappointed with EPA’s proposal.

For example, Earthjustice, which has represented a range of groups seeking tougher PM2.5 standards, said in a Jan. 6 statement, “EPA’s proposed action is not in line with the powerful scientific evidence that supports a substantial strengthening of soot standards.”

“This delayed proposed rule on soot is a disappointment and missed opportunity overall. Though aspects of EPA’s proposal would somewhat strengthen important public health protections, EPA is not living up to the ambitions of this administration to follow the science, protect public health, and advance environmental justice,” added Earthjustice attorney Seth Johnson.

And the American Lung Association (ALA) Jan. 6 said, “Rather than actually proposing the science-based, most protective 8 ug/m3 annual level or the 25 ug/m3 24-hour level, EPA is only inviting comments on those protective levels. This falls far short of what is needed to meet the White House’s stated goals of furthering public health and environmental justice.”

“Health organizations and experts are united in their ask of EPA to finalize the national standards for particle pollution at 8 ug/m3 for the annual standard and 25 ug/m3 for the 24-hour standard,” ALA says. EPA’s Clean Air Scientific Advisory Committee (CASAC) has called for an annual primary limit in the range of 8 ug/m3 to 10 ug/m3, while a majority of the panel also called for the daily limit to be strengthened to a range from 25 ug/m3 to 30 ug/m3.

But industry groups called into question the need to tighten the standards at all.

The current standards “are effective and will continue to build on significant improvements in air quality while protecting public health. There is no compelling scientific evidence or requirement under the Clean Air Act to support more stringent PM standards that would likely place new regulatory and cost burdens on state and local governments, businesses, and the public,” said the American Petroleum Institute Jan. 6.

“We are disappointed that the Administration did not consider maintaining the current NAAQS standards. A better approach would be to focus on supporting innovative solutions through the implementation of the existing standards and the unprecedented new investments made by Congress,” said the U.S. Chamber of Commerce.

The Portland Cement Association dubbed the proposal “yet another regulatory burden that will hamper the cement industry’s ability to manufacture sustainable construction materials to meet the nation’s infrastructure needs.”

In joint Jan. 6 comments, the American Forest and Paper Association and American Wood Council said, “We are disappointed that EPA is proposing to significantly tighten the current NAAQS Standard for particulate matter without a clear path to achieve it.” — Stuart Parker (