Air Quality

San Joaquin Valley Air BasinAir quality issues are prevalent due to the geography of the San Joaquin region, which is located within the federally designated San Joaquin Valley Air Basin. The basin is defined by the mountain and foothill ranges to the east and west, the San Joaquin County line to the north, and the Tehachapi and Sierra Nevada Mountains to the south.

According to the San Joaquin Valley Air Pollution Control District, our geography creates a giant bowl, which is an ideal condition for air pollution creation and retention.

Federal air quality regulations require Metropolitan Planning Organizations (MPOs) to monitor four air pollutants:
  • Ozone;
  • Particulate matter under 2.5 microns in diameter (PM 2.5);
  • Particulate matter under 10 microns in diameter (PM-10); and
  • Carbon Dioxide (CO).
The San Joaquin Valley is currently designated as nonattainment with respect to Federal air quality standards for ozone and PM 2.5; and has a maintenance plan for PM-10, as well as a maintenance plan for CO for the urbanized/metropolitan areas of Kern, Fresno, Stanislaus, and San Joaquin Counties.

As San Joaquin County's transportation planning agency, SJCOG is responsible for demonstrating that transportation plans and programs satisfy the requirements of the Clean Air Act.

Additionally, Senate Bill 375 (SB 375) was enacted to reduce greenhouse gas emissions from automobiles and light trucks through integrated transportation, land use, housing, and environmental planning. Under the law, SJCOG is tasked with developing a Sustainable Communities Strategy (SCS), a required element of the RTP that provides a plan for meeting greenhouse gas reduction targets set forth by the California Air Resources Board. By modeling travel demand and emissions data, SJCOG is able to show the air quality impacts of the projects and plans included in the RTP/SCS.

You can view or download the full technical report at the following link:
2015 Air Quality Conformity Analysis