On May 24, 2012, the Air Resources Board (ARB) approved the SIP revision for the federal lead standard, which U.S. EPA revised in 2008.The SIP revision addresses attainment of the federal lead standard in the South Coast Air Basin portion of Los Angeles County, the only area in California designated as nonattainment for lead. Lead concentrations in this nonattainment area have been below the level of the federal standard since December 2011.
