Regional Air Quality Plans -- San Joaquin Valley Unified APCD

This page updated June 30, 2003.

Air Quality Attainment Status

The San Joaquin Valley is nonattainment for both the federal and the State 1-hour ozone and PM10 standards. The Valley failed to attain the federal 1-hour ozone standard in 1999 and in 2001 was reclassified from Serious to Severe with a new attainment date deadline of 2005.

Criteria Pollutant

Attainment Status

Federal 1-hour Ozone Severe Nonattainment
State 1-hour Ozone Severe Nonattainment
Federal PM10 Serious Nonattainment
State PM10 Nonattainment


The San Joaquin Valley was originally classified as a Serious nonattainment area which required attainment of the ozone standard by 1999. Federal law requires a Serious ozone area to meet several core requirements that are generally considered adequate to get an area under this designation to attainment by 1999.

Despite the adoption of core measures for Serious ozone areas, the Valley was unable to achieve the federal ozone standard in 1999. In 2000, in response to California’s request, U.S. EPA re-classified the Valley to a Severe nonattainment area for the federal ozone standard and extended the Valley’s ozone attainment date to 2005.

The District has determined that it cannot attain the standard by 2005 and has elected to request a “bump up” to the highest nonattainment classification (extreme). This reclassification extends the attainment date to 2010 provided additional measures are undertaken, including setting stiffer stationary source permit requirements.

The formal request to U.S. EPA to reclassify the San Joaquin Valley as an Extreme ozone nonattainment area will be made in 2003; if the request is accepted, the District will revise its SIP to meet federal requirements for the Extreme classification.


The San Joaquin Valley was originally classified as a moderate PM10 nonattainment area with a December 31, 1994 attainment deadline. Because its moderate area plan showed it would not attain the PM10 standards on time, the Valley was reclassified to serious with a statutory attainment deadline of December 31, 2001.

In 1997, the Valley developed and ARB submitted a PM10 SIP to U.S. EPA. The Valley did not meet its 2001 attainment deadline. At the San Joaquin Valley District's request, the State withdrew the prior PM10 SIP in 2002. The agencies then focused on developing a new, stronger PM10 plan relying on improved science and identifying the full scope of control measures needed for attainment. The Valley adopted its 2003 PM10 Plan in June 2003, which ARB subsequently approved and submitted to U.S EPA.

San Joaquin Valley -- General Background