Additional Air Quality Designations for the 2006 24-Hour Fine Particle National Ambient Air Quality Standards, 110(k)(6) Correction and Technical Correction Related to Prior Designation, and Decisions Related to the 1997 Air Quality Designations and Classifications for the Annual Fine Particles National Ambient Air Quality Standards

On November 13, 2009, EPA promulgated air quality designations nationwide for all but three areas for the 2006 24-hour fine particle (PM<INF>2.5</INF>) National Ambient Air Quality Standards (NAAQS). This rule takes several additional actions related to the 2006 24-hour PM<INF>2.5</INF> NAAQS designations. It establishes the initial PM<INF>2.5</INF> air quality designations for three areas (Pinal County, Arizona; Plumas County, California; and Shasta County, California) and their respective surrounding counties that EPA deferred in the November 13, 2009 promulgated designations. Plumas and Shasta counties and their surrounding counties are being designated "unclassifiable/attainment," while a portion of Pinal County is being designated as "nonattainment." This action also includes a 110(k)(6) error correction (affecting Ravalli, Montana) and a technical correction (affecting Knoxville, Tennessee) related to the 2006 24-hour PM<INF>2.5</INF> NAAQS designations. Finally, in this action, EPA announces its decision to retain the current designation of unclassifiable/attainment for Harris County, Texas and Pinal County, Arizona for the 1997 annual PM<INF>2.5</INF> NAAQS.