Washington Aqueduct Water Testing

Water filtration systems at the Washington Aqueduct process Potomac River water for distribution to the National Capital Region, Washington, D.C., Feb. 18, 2026. The Washington Aqueduct, owned and operated by the U.S. Army Corps of Engineers, Baltimore District, produces an average of 150 million gallons of safe drinking water per day through multi-stage purification that meets or exceeds all EPA safety standards, serving wholesale customers DC Water, Arlington County and Fairfax Water. (U.S. Army Corps of Engineers photo by Jeremy Todd)