Approval and Promulgation of Implementation Plans; Designation of Areas for Air Quality Planning Purposes; California; South Coast Moderate Area Plan and Reclassification as Serious Nonattainment for the 2006 PM2.5

The Environmental Protection Agency (EPA) is proposing to approve state implementation plan (SIP) revisions submitted by California to address Clean Air Act (CAA or Act) requirements for the 2006 24-hour fine particulate matter (PM2.5) national ambient air quality standards (NAAQS) in the Los Angeles-South Coast Air Basin (South Coast) Moderate PM2.5 nonattainment area. These SIP revisions are the 2012 PM2.5 Plan, submitted February 13, 2013, and the 2015 Supplement, submitted March 4, 2015. The EPA is also proposing to reclassify the South Coast PM2.5 nonattainment area, including reservation areas of Indian Country and any other area of Indian Country within it where the EPA or a tribe has demonstrated that the tribe has jurisdiction, as a Serious nonattainment area for the 2006 PM2.5 NAAQS based on EPA's determination that the area cannot practicably attain this standard by the applicable Moderate area attainment date of December 31, 2015. Upon final reclassification as a Serious area, California will be required to submit a Serious area plan including a demonstration that the plan provides for attainment of the 2006 PM2.5 NAAQS by the applicable Serious area attainment date, which is no later than December 31, 2019, or by the most expeditious alternative date practicable, in accordance with the requirements of part D of Title I of the CAA.