Potomac Interceptor Sewer Reconstruction - Great Falls, Virginia

Potomac Interceptor Reconstruction Site - Great Falls, Virginia

Construction on the Potomac Interceptor, a major sewer line for the Washington region, is entering its final phase at the site near Potomac Heritage Trail in Great Falls, Virginia. Crews are wrapping up the final connections to the new infrastructure and soon, the area will look like its natural environment again. Reforestation and restoration of the trail are planned for late 2025.

The Project Team continues to work closely with local partners including NOVA parks, and local government agencies, to ensure a smooth and successful transition as we approach the end of construction.

About the Project

This project is focused on rehabilitating key segments of the Potomac Interceptor (PI), a critical part of the region’s sewer infrastructure. The section being upgraded is right next to our odor control facility at Great Falls and includes reconstruction of a manhole that runs along the Potomac Heritage Trail.

The system carries about 60 million gallons of wastewater every day from communities near Washington Dulles International Airport all the way to the Potomac Pumping station in Washington, DC. From there, the water goes to the Blue Plains Advanced Wastewater Treatment Plant to be treated before being safely released into the Potomac River.

The system serves several communities, including Fairfax and Loudoun Counties, the towns of Vienna and Herndon, Dulles Airport, and Montgomery County, Maryland. DC Water is leading this important effort to make sure the system stays reliable for years to come.

What's Being Done

  • Switching wastewater flow to the new pipes installed
  • Backfilling and securing all deep excavation areas
  • Removing construction equipment and clearing the site
  • Restoring the natural environment
  • Repaving River Park Drive
  • Rebuilding the Potomac Heritage Trail to its pre-construction conditions

Timeline

  • Design Started: May 2020
  • Construction Started: Spring 2022
  • Expected Completion: Spring 2026
  • Work Hours: 6:00 AM – 4:30 PM, Monday through Friday

Upcoming Meeting

Board of Directors Meeting

April 24, 2023

Monday 9:00 AM

Announcement

Christening of TBM Emily with DC Water Interim General Manager Matt Brown holding bottle of tap water to christen Emily
DC Water Welcomes the Community Underground to See the Potomac River Tunnel and Christens Tunnel Boring Machine Emily

DC Water celebrated the christening of Emily today. It’s the second giant tunnel boring machine (TBM) that will help build the 5.5-mile Potomac River Tunnel. The celebration continued with Community Day. Residents and families met Emily and stepped inside the tunnel where she will soon begin digging.

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Upcoming Meeting
Date
October 8, 2026
Thursday, 9:30 AM

Upcoming Events

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.