(a) Based upon EPA's review of the air quality data for the 3-year period 2007 to 2009, EPA determined that the Metropolitan Washington, District of Columbia-Maryland-Virginia (DC-MD-VA) 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 Metropolitan Washington, DC-MD-VA nonattainment area is not subject to the consequences of failing to attain pursuant to section 179(d).

(b) Based upon EPA's review of the air quality data for the 3-year period 2007 to 2009, Washington, DC-MD-VA moderate nonattainment area has attained the 1997 8-hour ozone NAAQS by the applicable attainment date of June 15, 2010. 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 Washington, DC-MD-VA moderate nonattainment area will not be reclassified for failure to attain by its applicable attainment date pursuant to section 181(b)(2)(A).

(c) Based upon EPA's review of the air quality data for the 3-year period 2013 to 2015, the Washington, DC-MD-VA 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 Clean Air Act 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 Washington, DC-MD-VA marginal nonattainment area will not be reclassified for failure to attain by its applicable attainment date pursuant to section 181(b)(2)(A).