Jump to main content or area navigation.

Contact EPA Pacific Southwest Air Program

Pacific Southwest, Region 9

Serving: Arizona, California, Hawaii, Nevada, Pacific Islands, Tribal Nations

Air Actions, California

Southeast Desert Air Actions

On this page:

You will need Adobe Reader to view some of the files on this page. See EPA's PDF page to learn more about PDF, and for a link to the free Adobe Reader.

  • March, 2015: Final rulemaking determining the South East Desert Air Quality Maintenance Area has attained the National Ambient Air Quality Standard for 1-hour ozoneĀ 
  • August, 2014: Proposed rule - Southeast Desert Air Quality Maintenance Area has attained the National Ambient Air Quality Standard for 1-hour ozone
  • December 2011: Final Determination of Failure to Attain the 1-hour Ozone Standard for San Joaquin Valley, South Coast and Southeast Desert
  • September 2011: Proposed Determinations of Failure to Attain the 1-hour Ozone Standard for San Joaquin Valley, South Coast and Southeast Desert

March, 2015: Final rulemaking determining the South East Desert Air Quality Maintenance Area has attained the National Ambient Air Quality Standard for 1-hour ozone

EPA has determined that the Southeast Desert nonattainment area has attained the 1979 1-hour ozone National Ambient Air Quality Standard (0.120 parts per million). The air quality improvement results in large part from the decrease in upwind emissions of ozone precursors, the chemical compounds that react form ozone in the lower atmosphere in the presence of sunlight.

The Southeast Desert is composed of parts of the Antelope Valley, Mojave Desert, and South Coast Air Quality Management Districts and includes portions of Los Angeles, Riverside and San Bernardino Counties. The area remains in nonattainment with the 8-hour ozone standard set in 2008 (0.075 parts per million).

August, 2014: Proposed rulemaking to determine the Southeast Desert Air Quality Maintenance Area has attained the National Ambient Air Quality Standard for 1-hour ozone

August 12, 2014: EPA is proposing to determine that the Southeast Desert nonattainment area has attained the 1-hour ozone National Ambient Air Quality Standard (0.120 parts per million). The air quality improvement results in large part from the decrease in upwind emissions of ozone precursors, the chemical compounds that react form ozone in the lower atmosphere in the presence of sunlight.


December 2011: Final Determination of Failure to Attain the 1-hour Ozone Standard for San Joaquin Valley, South Coast and Southeast Desert

December 16, 2011: EPA finalized its determination that the South Coast, San Joaquin Valley and the Southeast Desert 1-hour ozone nonattainment areas have failed to attain the 1-hour ozone standard by their applicable attainment date. This final action includes response to public comments.

September 2011: Proposed Determinations of Failure to Attain the 1-hour Ozone Standard for San Joaquin Valley, South Coast and Southeast Desert

September 1, 2011: EPA proposed to find that the South Coast, San Joaquin Valley and the Southeast Desert 1-hour ozone nonattainment areas have failed to attain the 1-hour ozone standard by their applicable attainment date. EPA is required to make these determinations to ensure implementation of certain 1-hour ozone requirements, such as contingency measures and section 185 major stationary source fee programs, which are given effect by such determinations.

Contact Information
Doris Lo (lo.doris@epa.gov)
(415) 972-3959

Jump to main content.