Public Workshop for the 9 µg/m3 Fine Particulate Matter National Ambient Air Quality Standard

Notice of Public Workshop for the 9 µg/m3 Fine Particulate Matter National Ambient Air Quality Standard: Designations

California Air Resources Board (CARB) staff invite you to participate in a public workshop on the evening of September 25, 2024, to kick off the State Implementation Plan (SIP) planning efforts for the 9 microgram per cubic meter (µg/m3) fine particulate matter (PM2.5) national ambient air quality standard (NAAQS or standard). This workshop will be the first in a series exploring various aspects of planning for the 9 µg/m3 PM2.5 standard which the State is required to undertake pursuant to the federal Clean Air Act (Act). During this first workshop, CARB staff will present key background information on the 9 µg/m3 standard and the science of PM2.5. Staff will also introduce the process for initially designating regions of the State for the purpose of implementing the standard. CARB staff encourage public engagement at this workshop and throughout the planning process, leading to submittal of SIPs to the U.S. Environmental Protection Agency (U.S. EPA) for designated nonattainment areas in late 2027. Staff will review some of the sources of PM2.5 in different areas of California and discuss how they inform control programs for PM2.5.

The workshop will be held both in person and on Zoom. The meeting will be conducted in English with Spanish interpretation available. Workshop materials, including the staff presentation and meeting recording, will be posted on the 9 µg/m3 SIP webpage.

Date: Wednesday, September 25, 2024
Time: 5:00 p.m. to 7:00 p.m.
In-person location: CalEPA Headquarters Building, Sierra Hearing Room (second
floor), 1001 I Street, Sacramento, CA 95814
Virtual location: Please register via Zoom

Background

The Act requires U.S. EPA to set health-based NAAQS for numerous pollutants, including PM2.5. On February 7, 2024, U.S. EPA strengthened the annual PM2.5 standard from 12.0 µg/m3 to 9.0 μg/m3, based on an integrated assessment of an extensive body of new scientific evidence, which improved the body of knowledge regarding PM2.5-related health effects.

The first step in addressing the lower standard is designating regions of the State as either attaining or not attaining the new standard. Preliminary analysis of data from California’s statewide air monitoring network conducted by CARB staff has identified areas that are anticipated to be nonattainment, attainment after exclusion of exceptional events (e.g., wildfires), or attainment/unclassifiable for the 9 μg/m3 standard. As shown in the map below, areas expected to be designated nonattainment are the South Coast, San Joaquin Valley, Bay Area, San Diego, Sacramento, Imperial, Yuba City-Marysville, Portola, and Mendocino. This workshop provides an opportunity for public feedback, input, and ideas on regions’ potential designations for the new PM2.5 standard.

Please contact SIP planning staff at sipplanning@arb.ca.gov with any questions regarding this workshop.