Fairfax County Water Authority (FCWA or more recently Fairfax Water for short) is the main water company in the Northern Virginia region of the United States, and one of the four major water providers in the Washington, D.C. metropolitan area (the other three being Virginia American Water, the Washington Aqueduct and the Washington Suburban Sanitary Commission). Fairfax Water serves most of the populated areas of Fairfax County, and also serves neighboring communities of Alexandria, Prince William County, Virginia and Loudoun County, Virginia through an interconnection with Virginia American Water, which purchases water through wholesale agreements. It serves drinking water to 1.5 million people.
FCWA does not provide sanitary sewer service; this is left to the individual jurisdictions it serves.