(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 (PM_2.5) nonattainment area attained the 1997 annual PM_2.5 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 PM_2.5 nonattainment area is not subject to the consequences of failing to attain pursuant to section 179(d).

(c) Based upon EPA's review of the air quality data for the three-year period 2005 to 2007, EPA determined, as of June 18, 2012, that the New York-Northern New Jersey-Long Island (NY-NJ-CT) one-hour ozone nonattainment area did not meet its applicable one-hour ozone attainment date of November 15, 2007. Separate from and independent of this determination, based on 2008-2010 complete, quality-assured ozone monitoring data at all monitoring sites in the area, and data for 2011, EPA determined, as of June 18, 2012, that the NY-NJ-CT one-hour ozone nonattainment area has attained the one-hour ozone standard.

(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).

(e) EPA has determined, as of August 21, 2019, that the Warren County Nonattainment Area has attained the 3-hour, 24-hour, and annual 1971 sulfur dioxide national ambient air quality standard (NAAQS). This determination (informally known as a Clean Data Determination) is based on air quality monitoring data, air quality dispersion modeling information, and other supporting information. This determination suspends the requirements for the State to submit a reasonable further progress plan, attainment demonstration, contingency measures and any other plan elements relating to attainment of the 3-hour, 24-hour, and annual 1971 SO₂ NAAQS for as long as the area continues to meet each NAAQS.