The South Coast Air Basin consists of Orange County, the urban portion of Los Angeles County, and the western portions of San Bernardino and Riverside Counties. The South Coast Air Quality Management District (District) has prepared a comprehensive air quality plan update for this area in consultation with the Air Resources Board and the Southern California Association of Governments. The District's "Air Quality Management Plan" or "AQMP" addresses federal Clean Air Act requirements for SIPs as well as California Clean Air Act requirements.
The SIP component will revise the region's demonstration of attainment for both the federal one-hour ozone standard by 2010 and the federal PM10 standard by 2006. Upon local, State, and federal approval, the 2003 Plan will replace the existing 1997/1999 Ozone SIP and 1997 PM10 SIP for the South Coast, plus the 2002 Coachella Valley PM10 Plan. The 2003 Plan uses more recent data on air quality, emissions and modeling to assess attainment. It will also include an updated control strategy for both stationary and mobile sources, reflecting new measures for local, State, and federal implementation. The District develops the local element with the Southern California Association of Governments; CARB prepares the State/federal element in consultation with the affected agencies.
The South Coast District Board adopted the local element on August 1, 2003. The CARB adopted the statewide element and approved the comprehensive SIP for the South Coast Air Basin and the PM10 SIP for the Coachella Valley on October 23, 2003. CARB submitted the South Coast and Coachella SIPs to U.S. EPA on January 9, 2004.