Additional Air Quality Designations for the 2006 24-Hour Fine Particle National Ambient Air Quality Standards

The EPA is taking final action to establish the initial 2006 24-hour fine particle (PM<INF>2.5</INF>) national ambient air quality standards (NAAQS) air quality designations for the Ak-Chin Indian Community located in Pinal County, Arizona, and the Gila River Indian Community located in Pinal County and Maricopa County, Arizona. On November 13, 2009, and February 3, 2011, the EPA promulgated air quality designations nationwide for all but these two areas for the 2006 24-hour PM<INF>2.5</INF> NAAQS. The EPA deferred initial PM<INF>2.5</INF> air quality designations for the Ak-Chin Indian Community and the Gila River Indian Community in the earlier promulgated designations.