District of Columbia—TSP
District of Columbia—1971 Sulfur Dioxide NAAQS
[Primary and Secondary]
District of Columbia—2010 Sulfur Dioxide NAAQS
[Primary]
1 Includes any Indian country in each county or area, unless otherwise specified. EPA is not determining the boundaries of any area of Indian country in this table, including any area of Indian country located in the larger designation area. The inclusion of any Indian country in the designation area is not a determination that the state has regulatory authority under the Clean Air Act for such Indian country.
2 This date is April 9, 2018, unless otherwise noted.
District of Columbia-Carbon Monoxide
1 This date is November 15, 1990, unless otherwise noted.
District of Columbia—Ozone (1-Hour Standard) 2
2 The 1-hour ozone standard is revoked effective June 15, 2005 for all areas in the District of Columbia.
District of Columbia—1997 Annual PM2.5 NAAQS
a Includes Indian Country located in each county or area, except as otherwise specified.
1 This date is 90 days after January 5, 2005, unless otherwise noted.
2 This date is July 2, 2014, unless otherwise noted.
District of Columbia—2012 Annual PM2.5 NAAQS
1 Includes areas of Indian country located in each county or area, except as otherwise specified.
2 This date is April 15, 2015, unless otherwise noted.
District of Columbia—1997 24-Hour PM2.5 NAAQS
District of Columbia—2006 24-Hour PM2.5 NAAQS
1 This date is 30 days after November 13, 2009, unless otherwise noted.
District of Columbia—NO2 (1971 Annual Standard)
District of Columbia—NO2 (2010 1-Hour Standard)
1 This date is 90 days after October 31, 2011, unless otherwise noted.
District of Columbia—1997 8-Hour Ozone NAAQS
1 This date is June 15, 2004, unless otherwise noted.
District of Columbia—2008 8-Hour Ozone NAAQS
1 Excludes Indian country located in each area, unless otherwise noted.
District of Columbia—2015 8-Hour Ozone NAAQS
2 This date is August 3, 2018, unless otherwise noted.
District of Columbia—2008 Lead NAAQS
1 December 31, 2011 unless otherwise noted.