The 4,360-acre Andrews Air Force Base (AAFB) site is an active U.S. Department of Defense facility in Camp Springs, Maryland, about five miles southeast of Washington, D.C. The base has been in operation since 1942. It includes runways and airfield operational areas, an industrial area, and housing and recreation facilities. Past activities at the site contaminated soil, sediment, surface water and groundwater with petroleum and hazardous chemicals. Investigation and cleanup activities are ongoing.