Drinking Water Treatment

Drinking water for the District of Columbia comes from the Potomac River. The U.S. Army Corps of Engineers Washington Aqueduct, a federal drinking water treatment plant, collects water from the Potomac River at Great Falls and Little Falls. The Aqueduct treats this water to make sure it meets federal drinking water requirements and is safe to drink. DC Water purchases treated drinking water from the Washington Aqueduct and distributes it to our customers.

The Aqueduct draws water from the Potomac River and treats it at two treatment plants, Dalecarlia and McMillan. Here, water from the Potomac River is treated to meet safe drinking water standards in a multistep process. For more information on the drinking water treatment process, visit the Aqueduct's website. 

Drinking Water Distribution System 

DC Water distributes the water that has been treated at the Aqueduct though a series of more than 1,300 miles of pipes that run underground. As the water travels through the pipes to individual homes and other buildings, DC Water monitors the system to ensure that only safe, high quality water reaches our customers. DC Water maintains the underground pipe system that begins at the water treatment plant and ends at private service lines, the pipes that connect a home or other building to the public water main in the street.