California Air Resources Board

SACRAMENTO – The California Air Resources Board is calling on the U.S. Environmental Protection Agency to approve its plans to meet the eight hour ozone standard for both Southern and Central California and is revoking its plan to attain the one-hour ozone standard in Southern California.

ARB staff decided to pull the outdated 2003 one-hour ozone standard plan back since there is already a one hour State Implementation Plan, or "SIP," in place for Southern California that the U.S. EPA approved in 2001. This SIP has helped reduce smog-forming emissions in Southern California at unprecedented rates: Although ozone concentrations in the South Coast were more than twice the standard during the mid-1990s, today more than 60 percent of the area's population live and work in areas that meet the standard. These areas include nearly all of Orange County and the coastal region of Los Angeles County.

ARB will not rescind its one hour ozone SIP for the Central Valley since there is no other plan in place for reducing the region's smog-forming emissions.

"At this point, the current SIP is no more than a paperwork exercise. We have the framework in place to reduce South Coast ozone emissions already and have passed the halfway mark in terms of being where we need to be by 2010," said ARB Chairman Mary Nichols. "We now need the U.S. EPA to act on our eight-hour ozone standard plans."

The U.S. EPA set a new eight-hour ozone standard in 1997 that largely supersedes the previous one-hour standard since it is more stringent and protective. The eight-hour standard protects the public against chronic health effects from day-long episodes to unhealthy ozone concentrations as compared to one-hour exposures.

ARB submitted eight-hour ozone SIPs for both the Central Valley and Southern California to the U.S. EPA in November. These SIPs include measures that will reduce thousands of deaths and illnesses associated with smog exposure. The U.S. EPA never acted on the 15-year-old plan that ARB is rescinding today.