About The District

The San Joaquin Valley Air Pollution Control
District is made up of eight counties in
California’s Central Valley: San Joaquin,
Stanislaus, Merced, Madera, Fresno, Kings, Tulare and the San Joaquin Valley Air Basin portion of Kern.

The Valley Air District is governed by a fifteen member Governing Board consisting of representatives from the Board of Supervisors of all eight counties, one Health and Science member, appointed by the Governor, one Physician, appointed by the Governor and five Valley city representatives.

General PowerPoint on San Joaquin Valley
Air Quality Issues

Valley Air District Map

The Air District’s Mission

The San Joaquin Valley Air District is a public health agency whose mission is to improve the health and quality of life for all Valley residents through efficient, effective and entrepreneurial air quality management strategies. Our Core Values have been designed to ensure that our mission is accomplished through commonsense, feasible measures that are based on sound science.

The Air District’s Vision

Healthful air that meets or exceeds air quality standards for all Valley residents. The District is a leader in air-pollution control. Valley residents take pride in our collective efforts to continuously improve air quality.

Core Values

  • Protection of Public Health – The District shall continue to strive to protect the health of Valley residents through efforts to meet health-based state and federal ambient air-quality standards, based on science and prioritized where possible using health-risk reduction strategies.

  • Active and Effective Air Pollution Control Efforts while Seeking to Improve the Valley’s Economic Prosperity and Grow Opportunities for All Valley Residents – District staff shall work diligently to adopt and fully implement cost-effective air pollution-control measures, provide meaningful incentives for reducing emissions, and develop creative alternatives for achieving emissions reductions.

  • Outstanding Customer Service – District staff shall work to provide excellent customer service for stakeholders in activities including: rule and plan development; permitting and emissions inventory functions; compliance activities; financial and grant-funding transactions; and responses to public complaints and inquiries.

  • Ingenuity and innovation - The District values innovation and ingenuity in meeting the challenges we face. Examples of this spirit of innovation include developing programs that provide new incentives for emissions reductions, and providing alternate compliance strategies that supplement traditional regulatory efforts and generate more emissions reductions than could otherwise be reasonably obtained.

  • Accountability to the public – The District serves, and is ultimately accountable to, the people of the Valley for the wise and appropriate use of public resources, and for accomplishing the District’s mission with integrity and honesty.

  • Open and transparent public processes – The District shall continue to provide meaningful opportunities for public input and be responsive to all public inquiries.

  • Recognition of the uniqueness of the San Joaquin Valley – The Valley’s meteorology, topography and economy differ significantly from those in other jurisdictions. Although it is valuable to review and evaluate efforts of other agencies, we must consistently look for solutions that fully consider the Valley’s unique needs.

  • Continuous improvement –The District works to continually improve its internal operations and processes, and strives to streamline District operations through optimally utilizing information technology and human resources.

  • Effective and efficient use of public funds – The District shall continually strive to efficiently use all resources and to minimize costs associated with District functions.

  • Respect for the Opinions and Interest of All Valley Residents – The District shall respect the interests and opinions of all Valley residents and fully consider these opinions, seeking collaboration with federal, state, and local agencies, agriculture, businesses, community groups and residents in carrying out the District’s mission.

  • Robust Public Outreach and Education on Valley Air Quality Progress and Continuing Air Quality Efforts – As we move forward in achieving our mission, the District shall continue its ongoing efforts to educate the public about air quality, and the significant clean air investments and air quality progress that have been made in the Valley.

STAR Culture

The District takes great pride in its STAR work culture which promotes excellent customer service, positive staff morale, outstanding attitude, and exceptionally high level of productivity and innovation.

The Jurisdiction Puzzle

Federal and state laws require emission control measures in areas where air pollution exceeds standards. The San Joaquin Valley is one of these areas. With a variety of state and federal agencies implementing air pollution reduction programs, it can be difficult to understand the mission and jurisdiction of each organization.

The federal government, primarily through the Environmental Protection Agency, sets standards, oversees state and local actions, and implements programs for toxic air pollutants, heavy-duty trucks, locomotives, ships, aircraft, off-road diesel equipment, and some types of industrial equipment.

State government, through the Air Resources Board and Bureau of Automotive Repair, sets more stringent state standards, oversees local actions, and implements programs for motor vehicle emissions, fuels, and smog checks.

Local air pollution control districts, such as the San Joaquin Valley Air Pollution Control District (Valley Air District), develop plans and implement control measures in their areas. These controls primarily affect stationary sources such as factories and plants. Local air districts also conduct public education and outreach efforts such as the Valley Air District’s Healthy Air Living, Wood Burning, and Smoking Vehicle voluntary programs.

Local cities and counties are responsible for implementing air friendly community planning that promotes pedestrian traffic, commute alternatives and cleaner transit fleets.

While their jurisdiction and specific programs may vary, all of these organizations share a common goal: to work cooperatively in establishing comprehensive air quality control programs to benefit all California residents.

Where the District Gets its Funding

The revenue to fund the District’s annual operating budget comes from the following three sources:

  • Permit fees paid annually by applicable businesses operating within the District.
  • Motor vehicle registration fees generated by a $19 surcharge fee for every vehicle registered within the District. A part of these fees are used for the internal operations of the District and a portion is distributed to qualified applicants for programs intended to reduce vehicle emissions.
  • The District receives federal and state grants annually from the California Air Resources Board and the United States Environmental Protection Agency.

The chart (below) illustrates the approximate breakdown of the three revenue sources by percentage:

Operating Budget

Making Progress

Air pollution within the District comes from a variety of sources. These include industrial facilities, vehicles and consumer products. The pie chart below illustrates the sources of ozone components and their levels.

Sources of Emissions in the San Joaquin Valley, 2023

NOx Emissions
VOC Emissions
PM2.5 Emissions

Emissions of reactive organic gases and oxides of nitrogen
Estimated by California Air Resources Board

After billions of dollars of investment by Valley businesses, pioneering air quality regulations and consistent effort by Valley residents, the Valley air basin has made historic improvements in air quality.

Despite natural challenges such as the geography, topography and meteorology of the air basin, which create a low capacity for air pollution, the Valley has worked its way up from nonattainment to attainment of critical health standards. Air quality in the Los Angeles area is only marginally worse than the Valley’s although about 10 times more pollution is emitted in that region. The Bay Area’s air quality is much better than the Valley’s, even though about six times more pollution is released there.

Yet the Valley has reduced emissions at the same rate or better than other areas in California and set unparalleled achievement milestones in the process.

  • In the 1990s, the Valley became the first air basin classified as “serious nonattainment” to come into attainment of health standards for coarse particulate matter (PM10).
  • In 2013, for the first time in recorded history, the Valley had zero violations of the hourly ozone standard established under the federal Clean Air Act, down from 281 violations in 1996 and seven violations in 2012. This remarkable achievement makes the Valley the first air basin in the country to improve from a designation of “extreme” nonattainment to attainment of an air pollutant.

Emission reductions are required by federal and state mandates such as the Federal Clean Air Act amendments and the California Clean Air Act. Though effective air pollution control programs are still needed, past efforts have brought about a significant improvement in air quality (see below).

Ozone Season Good and Unhealthy AQI County-Days

Since 2002, the number of days in each county where the Valley’s air quality was meeting the health standards has steadily improved, while the number of days exceeding the health standards has decreased significantly. In the past, 47% of the days had air quality exceeding a health standard, where in 2022, only 14% of days exceeded a health standard, while 86% of the days met all air quality standards.

Winter Season Air Quality Trends by Air Quality Index

Through the implementation of air quality improvement strategies in the Valley over the past 20 years, concentrations of PM2.5 during the winter season have decreased significantly across the region. Since the 2002-03 winter season, the number of days where the PM2.5 standard was exceeded has decreased from 39% to only 7%, while during the 2022-23 winter season, 93% of the days met the PM2.5 health standard.

Criteria Pollutants

Pollutant Status
Lead Attainment
Nitrogen Dioxide Attainment
Sulfur Dioxide Attainment
Carbon Monoxide Attainment
PM10 Attainment
Ozone, 1-hr standard (revoked) Attainment. In 2016 EPA determined that the District attained the standard based on sufficient, quality-assured, and certified data for the 2012-2014 monitoring period. The San Joaquin Valley is the first and only region to be classified as "Extreme Nonattainment" to then attain the standard.
Ozone, 8-hr standard 1997 Standard 84 ppb (Nonattainment): Continuing to make progress towards this standard, projected to attain by 2023. Days exceeding standard reduced by over 90%.
2008 Standard 75 ppb (Nonattainment): Continuing to make progress towards this standard, projected to attain by 2031. Days exceeding standard reduced by over 59%.
2015 Standard 70 ppb (Nonattainment): Continuing to make progress towards this standard, projected to attain by 2037. Days exceeding this standard reduced by over 46%.   
PM2.5 Attainment. 1997 24-hour Standard 65 µg/m3: In 2022 EPA determined that the District attained the standard based on sufficient, quality-assured, and certified data for 2018-2020 monitoring period.
1997 Annual Standard 15 µg/m3 (Nonattainment): Continuing to make progress towards this standard, projected to attain by 2023.
2006 24-hour Standard 35 µg/m3 (Nonattainment): Continuing to make progress towards this standard, projected to attain by 2024.
2012 Annual Standard 12 µg/m3 (Nonattainment): Continuing to make progress towards this standard, projected to attain by 2030.