The California Air Resources Board (CARB) has adopted a plan that demonstrates to the US Environmental Protection Agency how the San Joaquin Valley air basin will attain each of four federal standards for fine particulate matter by regulatory deadlines.
Meeting standards for fine particle pollution, or PM2.5, is the San Joaquin Valley’s most critical air quality challenge. The San Joaquin Valley has the worst particulate matter pollution in California—and the worst in the nation for annual federal standards. The newly adopted 2018 Valley PM2.5 Plan is expected to result in significant improvement in air quality by 2024. . . .
Particulate matter, which can be made up of soot, soil, dust and sulfate particles, comes from a variety of sources, but primarily from the burning of carbon-based fuels, such as gasoline, diesel and wood. In the San Joaquin Valley, car and truck emissions make up about half of measured airborne PM2.5, and local sources, such as wood smoke and dust, make up the other half.
Despite progress—existing CARB strategies such as engine and fuels standards have reduced Valley NOx emissions by 60% and Valley Air District programs have reduced PM2.5 emissions by nearly 40%—PM2.5 emissions are expected to rise as the population grows.
Currently, the Valley is designated non-attainment for the following federal health-based standards for PM2.5: the 1997 24-hour (65 micrograms per cubic meter) and annual (15 ug/m3) standards, and the 2006 24-hour (35 ug/m3) and 2012 annual (12 ug/m3) standards. Deadlines for attaining these standards are 2020, 2024 and 2025, respectively. (The 2020 deadline is for both 1997 standards.)
Measures for reducing emissions include:
New regulations targeting emissions from heavy-duty trucks, including an inspection and maintenance program, a low-NOx engine standard and a low-emission diesel fuel requirement.
Tightened controls on residential wood-burning stoves and fireplaces, and enhanced incentives for cleaner-burning alternatives.
Enhanced incentives for purchase of cleaner agricultural equipment and commercial underfired charbroilers.
A suite of measures to reduce emissions of NOx from flares, including flares at refineries, oil fields and landfills, internal combustion engines and boilers, among other sources.
CARB expects significant benefits from the plan. For example, the city of Fresno is predicted to see a 40% improvement in air quality between 2013 (the base year of the plan) and 2024, when the Valley is expected to attain the 35 ug/m3 standard). The Valley Air District has committed to an aggregate reduction of 1.3 tons per day of directly emitted PM2.5 emissions and 1.9 tons per day of NNOxOx emissions in 2024.