01

Enhanced water quality monitoring

The Washington Aqueduct upgraded its data sonde to provide early warnings for seasonal algal blooms and potential sewage spills.

02

National Water Quality Month

Every day, the Washington Aqueduct produces and delivers 135 million gallons of safe, high-quality drinking water to one million people in the NCR.

03

Secure the Source Study

USACE, WSSC Water, Fairfax Water, and regional partners announced the launch of Secure the Source study to evaluate potential secondary water supply.

04

Georgetown Castle Restoration

115 years after its original construction, USACE began to rehabilitate the Georgetown Castle as part of an improvement project.

05

Regional Drought Watch

Washington Aqueduct officials reassure its more than one million customers that the region’s water infrastructure is fully prepared to handle the dry...

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06

How Washington Aqueduct Works

Examine the history & current operations of the Washington Aqueduct, a USACE mission that supplies water to Washington D.C. & surrounding communities.

Welcome to the Washington Aqueduct

Providing Safe, Reliable Drinking Water to the Nation’s Capital and Surrounding Communities

The Washington Aqueduct, a division of the U.S. Army Corps of Engineers (USACE) Baltimore District, is responsible for producing safe, reliable, and cost-effective drinking water for approximately one million citizens. Drawing from the Potomac River, we proudly serve as the wholesale water supplier for the District of Columbia (DC Water), Arlington County, and Fairfax Water in Virginia.

Our Mission

The mission of the Washington Aqueduct is to collect, purify, and pump an adequate supply of drinking water for its wholesale customers: DC Water, Arlington County, and Fairfax Water. 

 

 

Our Vision

Washington Aqueduct's vision is to be a leader in the water treatment and supply industry employing state of the art technology, highly-skilled and trained personnel, creative solutions and modern processes.

 

Water Quality and Consumer Confidence

Transparency and public safety are our top priorities. We continuously monitor and test our water throughout the treatment process to ensure compliance with strict Environmental Protection Agency (EPA) regulations.

Citizens and municipal partners can review our safety metrics, testing results, and operational data in our official reports:

Our Mission and Operations

Since 1853, the Washington Aqueduct has been a critical component of the National Capital Region's infrastructure. Our mission is to protect public health by treating and transmitting high-quality water that meets or exceeds all federal and state standards.

We operate a complex raw water transmission system and two primary treatment facilities:

  • The Dalecarlia Water Treatment Plant

  • The McMillan Water Treatment Plant

Together, these facilities process an average of 135 million gallons of water per day, ensuring uninterrupted service for residents, businesses, and federal facilities across the region.

Contact Information and Public Resources

We are committed to maintaining open communication with the communities we serve. For media inquiries, operational questions, or community relations, please reach out to our Public Affairs Office.

Email: WashingtonAqueductInquiries@usace.army.mil

Address:
5900 MacArthur Boulevard
Washington, D.C. 20016-2514

Emergency Contact: For local water main breaks or billing issues, please contact your local retail provider DC Water, Arlington County, or Fairfax Water.

WATER TREATMENT 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.
WATER QUALITY 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.
WATER SECURITY Washington Aqueduct's newly restored Georgetown Gatehouse, Washington, D.C.