Ambient Air Monitoring Network

Learn about the Air District's ambient air monitoring network and special air quality studies.

The Air District maintains one of the most comprehensive air quality monitoring networks in the country, consisting of over 30 stations distributed among the nine Bay Area counties.

This network measures concentrations of pollutants for which health-based ambient air quality standards have been set by the U.S. Environmental Protection Agency and the California Air Resources Board. The network also measures concentrations of various pollutants designated as Toxic Air Contaminants by the state of California.

This information is used to determine compliance with state and federal air quality standards, prepare air quality forecasts, develop air quality plans, provide information for permit modeling, prepare environmental impact reports, and track air quality trends.

Pollutants measured by the monitoring network include:

  • Ground-level ozone
  • Carbon monoxide
  • Nitrogen oxides
  • Sulfur dioxide/oxides
  • Particulate matter
  • Hydrogen sulfide

Sulfur Dioxide Data Requirements Rule Compliance Information

On March 18, 2016, the U.S. Environmental Protection Agency sent a letter to the California Air Resources Board, informing the state that they considered three sources in Martinez, California, to be aggregated with respect to triggering compliance with the sulfur dioxide Data Requirements Rule ambient air characterization requirements. These sources are the Shell and Tesoro refineries and the Eco Services sulfur recovery plant. 

The Air District prepared an analysis outlining the proposed compliance with the sulfur dioxide Data Requirements Rule through ambient air monitoring. The Air District solicited comments from the public on this analysis from September 29 through October 31, 2016, and submitted it to the EPA. The EPA approved this approach on December 6, 2016. This information will be included in future Ambient Air Monitoring Network Reports.

2015 Air Monitoring Network Plan

The Air District released its latest Ambient Air Monitoring Network Report in July 2016. The report describes the District’s air monitoring network for 2015. It also describes the objectives of the monitoring network and lists proposed changes to the network planned to occur before June 30, 2017. The proposed changes may be found in the section titled Proposed Modifications to Network in 2016-2017. The District solicited comments from the public on these proposed changes to the air monitoring network. The public comment period ended June 25, 2016.

The next annual Ambient Air Monitoring Network Report is scheduled for release in July 2017.

2014 Air Monitoring Network Plan

The Air District released the2014 Ambient Air Monitoring Network Planin 2015. The report described the District’s air monitoring network for 2014, the objectives of the monitoring network, and proposed changes to the network. The proposed changes may be found in the section titled Proposed Modifications to Network in 2015-2016. It describes the objectives of the monitoring network and proposed changes planned to occur before June 30, 2015. The District solicited comments from the public on proposed changes to the air monitoring network. The public comment period ended June 30, 2015.


Spare the Air Status
Spare the Air Status
  • Monday,
    5/29

    No Spare the Air Alert in Effect

  • Tuesday,
    5/30

    No Spare the Air Alert in Effect

Last Updated: 9/27/2016