Pease Air National Guard Base is a New Hampshire Air National Guard base located at Portsmouth International Airport at Pease in New Hampshire. It occupies a portion of what was once Pease Air Force Base, a former Strategic Air Command facility with a base-related population of 10,000 and which was home to the 509th Bomb Wing (509 BW) flying the General Dynamics FB-111A. Pease AFB was closed pursuant to 1991 Base Realignment and Closure Commission action, with the 509 BW transferring to Whiteman AFB, Missouri. In 1983, investigations had shown soil and water contamination with degreasers and JP-4 jet fuel, and in 1990 the base was put on the National Priorities List of superfund sites. As of 2015, after 25 years of the Pease Development Authority's work, Pease International Tradeport has 275 businesses employing close to 10,000 civilian workers. Pease continues to be home to the New Hampshire Air National Guard's 157th Air Refueling Wing (157 ARW), an Air Mobility Command gained Air National Guard unit, and since 2009 the 64th Air Refueling Squadron, an active duty United States Air Force "associate" unit to the 157th. The 157 ARW was a former tenant activity at Pease AFB and remained at the installation following the BRAC-directed closure of its regular Air Force activities. As of 2011, the base population is 380 full-time military personnel, with a monthly surge of up to 950 when part-time military personnel are included. Location Pease Air Force Base occupied of land in total, with roughly 40 percent in the city of Portsmouth and 60 percent in the town of Newington, plus a small amount of golf course acreage in Greenland, all within Rockingham County in the Seacoast Region of New Hampshire. Pease Air National Guard Base is approximately in size, and as of September 2014 included 46 structures. It is located approximately from Manchester, Portland, and Boston — major cities of New Hampshire, Maine, and Massachusetts, respectively. History What would become Pease Air Force Base started as the Portsmouth Municipal Airport in the 1930s. With the onset of World War II, improvements to the airport were announced in December 1941. The airport was closed to civilian traffic effective August 1942, as part of defense measures along the east coast. Civil Air Patrol usage started in February 1944, and in August the airport was leased to the U.S. Navy, who already had a nearby presence at Portsmouth