The Environmental Protection Agency (EPA) is redesignating the Central New Hampshire nonattainment area from nonattainment to attainment for the 2010 1-hour primary sulfur dioxide (SO<INF>2</INF>) national ambient air quality standard (NAAQS). EPA is also approving the maintenance plan submitted by the State of New Hampshire for the area for the SO<INF>2</INF> NAAQS. This nonattainment area consists of portions of Hillsborough County, Merrimack County, and Rockingham County, New Hampshire. The primary emission source in the area is now subject to federally-enforceable emission control standards, and air quality in the area now meets the SO<INF>2</INF> NAAQS. This action is being taken under the Clean Air Act.