The Environmental Protection Agency (EPA) is proposing to determine that the San Joaquin Valley, California fine particulate matter (PM2.5) nonattainment area attained the 1997 annual PM2.5 national ambient air quality standards (NAAQS). This proposed determination is based on ambient air quality monitoring data from 2022 through 2024. This is a very significant milestone for the San Joaquin Valley in terms of air quality. Unfortunately, EPA has kept moving the goalposts and established additional ambient air quality standards, especially for PM2.5 and the San Joaquin Valley has been forced to keep adopting rules and regulations to meet these tougher standards. The standard for which this ruling is being proposed is 15 µg/m3. New PM2.5 standards have since been established including 12 µg/m3 in 2012 and 9 µg/m3 in 2024. To get to this status has been painful for the industry given all of the rules and regulations that have been adopted and implemented to get to this point. According to the District, emissions of air pollutants from stationary sources has been reduced by over 93%.
