(a) Determination of Attainment: Effective February 6, 2013, EPA has determined that, based on 2009 to 2011 ambient air quality data, the Nogales PM_2.5 nonattainment area has attained the 2006 24-hour PM_2.5 NAAQS. This determination suspends the requirements for this area to submit an attainment demonstration, associated reasonably available control measures, a reasonable further progress plan, contingency measures, and other planning SIPs related to attainment for as long as this area continues to attain the 2006 24-hour PM_2.5 NAAQS. If EPA determines, after notice-and-comment rulemaking, that this area no longer meets the 2006 PM_2.5 NAAQS, the corresponding determination of attainment for that area shall be withdrawn.

(b) Determination of Attainment: Effective October 4, 2013, EPA has determined that, based on 2010 to 2012 ambient air quality data, the West Central Pinal PM_2.5 nonattainment area has attained the 2006 24-hour PM_2.5 NAAQS. This determination suspends the requirements for this area to submit an attainment demonstration, associated reasonably available control measures, a reasonable further progress plan, contingency measures, and other planning SIPs related to attainment for as long as this area continues to attain the 2006 24-hour PM_2.5 NAAQS. If EPA determines, after notice-and-comment rulemaking, that this area no longer meets the 2006 PM_2.5 NAAQS, the corresponding determination of attainment for that area shall be withdrawn.

(c) Determination of attainment. Effective June 9, 2017, the EPA has determined that, based on 2013 to 2015 ambient air quality data, the Nogales, AZ PM_2.5 nonattainment area has attained the 2006 24-hour PM_2.5 NAAQS by the applicable attainment date of December 31, 2015. Therefore, the EPA has met the requirement pursuant to CAA section 188(b)(2) to determine whether the area attained the standard. The EPA also has determined that the Nogales, AZ nonattainment area will not be reclassified for failure to attain by its applicable attainment date under section 188(b)(2).

(d) Determination of attainment. Effective November 4, 2019, the EPA has determined that, based on 2015 to 2017 ambient air quality data, the West Central Pinal County, AZ PM_2.5 nonattainment area has attained the 2006 24-hour PM_2.5 NAAQS by the applicable attainment date of December 31, 2017. Therefore, the EPA has met the requirement pursuant to CAA section 188(b)(2) to determine whether the area attained the standard. The EPA also has determined that the West Central Pinal County, AZ nonattainment area will not be reclassified for failure to attain by its applicable attainment date under section 188(b)(2).