The Largest Advanced Wastewater Treatment Plant in the World

DC Water’s Blue Plains Advanced Wastewater Treatment Plant is the largest plant of its kind in the world. On an average day, the facility treats close to 300 million gallons of wastewater with a daily capacity of 384 million gallons and the ability to treat over 780 million gallons a day at peak flow. Wastewater flows in from the District of Columbia and from Montgomery and Prince George’s Counties in Maryland and Fairfax and Loudoun counties in Virginia.

The plant opened as a primary treatment facility in 1937. Since that time, new processes and technologies have been added to provide advanced wastewater treatment. The Blue Plains facility now uses both primary and secondary treatment as well as denitrification, multimedia filtration and chlorination/dechlorination during the treatment process.

At DC Water, we believe wastewater is more than just waste. During the treatment process, useful products like biosolids and energy are extracted to be reused. We land apply our biosolids across the region, recycling nitrogen and phosphorous back into local soils. The thermal hydrolysis process used in our digesters also generates electricity, enough to support a quarter of the power usage at Blue Plains. These efforts help to continue to improve our treatment process and remain a leader in sustainability for the future.

For more information on the Blue Plains Advanced Wastewater Treatment Plant, we encourage you to take an in-person or virtual tour

Upcoming Meeting

Board of Directors Meeting

April 24, 2023

Monday 9:00 AM

Announcement

Aerial View of Construction near Watergate Complex Shows cranes and construction of drop shaft underway
Scaffolding Installation Begins near Watergate Complex for Potomac River Tunnel Project

Rock Creek and Potomac Parkway NW Beginning September 23, 2025, to Mid-November 2025

DC Water is installing temporary scaffolding at the Rock Creek Trail site, west of the Watergate Complex. Trail users are advised to adhere to flagger instructions during installation.

Scaffolding installation is expected to be completed by September 26, 2025, and will remain in place until mid-November 2025.

Latest Blog Post
A helicopter lowers a drill rig to workers on the Potomac River.
DC Water begins drilling in Potomac River to explore options to rehab underwater sewer line
When one of your major sewer lines runs through the Potomac River, a backhoe and trencher won't do. That's why we've got helicopters carrying a 14-ton drill and workers suspended midair over the Potomac.
Upcoming Meeting
Date
October 7, 2025
Tuesday, 9:30 AM

Upcoming Events

Customer Service Center Announcement

Payment Plan Incentive: provides a credit back of 40% of the last 3 payments made and in the new fiscal year 50% will be credited. Eligible participants are residential customers who have had an outstanding balance for 60 days or greater and with an outstanding balance of $500 or more.