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

DC Water Officials with NPS and ANC commissioners doing ceremonial groundbreaking
DC Water Breaks Ground on Piney Branch Tunnel, Final Phase of DC Clean Rivers Project

Today, DC Water broke ground on the Piney Branch Tunnel, the final major tunnel in our Clean Rivers Project. This work will help keep sewage and trash out of local waterways and make Rock Creek, the Potomac River, and the Chesapeake Bay cleaner for our community.

When we finish the Piney Branch Tunnel, it will hold at least 4.2 million gallons of rainwater and wastewater during heavy storms. Instead of overflowing into Piney Branch, that water will go to the Blue Plains Water Resource Recovery Facility, where it will be treated.

Latest Blog Post
Five photos from the American Water Works Association (AWWA) ACE26 conference featuring panel discussions, technical presentations, networking, and attendees posing at the ACE26 display.
ACE26 Highlights: How DC Water Advanced the Conversation on Water
More than 80 DC Water employees joined thousands of water professionals in Washington, D.C., sharing expertise, building partnerships and advancing conversations that will help shape the future of water.
Upcoming Meeting
Date
July 23, 2026
Thursday, 9:30 AM

Upcoming Events

Jul 23
Jul 25

Customer Service Center Announcement

Payment Plan Incentive: provides a credit back of 50% of the last 3 payments made. 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.