Section 52.425 - Determinations of attainment(a) Based upon EPA's review of the air quality data for the 3-year period 2008 to 2010, EPA determined that Philadelphia-Wilmington-Atlantic City, PA-NJ-MD-DE 8-hour ozone moderate nonattainment area (the Philadelphia Area) attained the 1997 8-hour ozone National Ambient Air Quality Standard (NAAQS) by the applicable attainment date of June 15, 2011. Therefore, EPA has met the requirement pursuant to CAA section 181(b)(2)(A) to determine, based on the area's air quality as of the attainment date, whether the area attained the standard. EPA also determined that the Philadelphia Area nonattainment area will not be reclassified for failure to attain by its applicable attainment date under section 181(b)(2)(A).(b) Based upon EPA's review of the air quality data for the 3-year period 2007 to 2009, EPA determined that the Philadelphia-Wilmington, PA-NJ-DE fine particle (PM2.5) nonattainment area attained the 1997 annual PM2.5 National Ambient Air Quality Standard (NAAQS) by the applicable attainment date of April 5, 2010. Therefore, EPA has met the requirement pursuant to CAA section 179(c) to determine, based on the area's air quality as of the attainment date, whether the area attained the standard. EPA also determined that the Philadelphia-Wilmington, PA-NJ-DE PM2.5 nonattainment area is not subject to the consequences of failing to attain pursuant to section 179(d).(c) The EPA has determined, as of June 3, 2016, that based on 2012 to 2014 ambient air quality data, the Seaford, DE 2008 ozone Marginal nonattainment area has attained the 2008 ozone NAAQS by the applicable attainment date of July 20, 2015. Therefore, the EPA has met the requirement pursuant to CAA section 181(b)(2)(A) to determine, based on the area's air quality data as of the attainment date, whether the area attained the standard. The EPA also determined that the Seaford nonattainment area will not be reclassified for failure to attain by its applicable attainment date under section 181(b)(2)(A).(d) Based upon EPA's review of the air quality data for the 3-year period 2013 to 2015, Philadelphia-Wilmington-Atlantic City, PA-NJ-MD-DE marginal ozone nonattainment area has attained the 2008 8-hour ozone national ambient air quality standard (NAAQS) by the applicable attainment date of July 20, 2016. Therefore, EPA has met the requirement pursuant to CAA section 181(b)(2)(A) to determine, based on the area's air quality as of the attainment date, whether the area attained the standard. EPA also determined that the Philadelphia-Wilmington-Atlantic City, PA-NJ-MD-DE marginal ozone nonattainment area will not be reclassified for failure to attain by its applicable attainment date pursuant to section 181(b)(2)(A). 77 FR 17343 , Mar. 26, 2012, as amended at 77 FR 28784 , May 16, 2012; 81 FR 26709 , May 4, 2016; 82 FR 50819 , Nov. 2, 2017 81 FR 26709 , 5/4/2016; 82 FR 50819 , 12/4/2017