DC Water is preparing to begin eight-months of construction on a major sewer line that runs along Clara Barton Parkway near I-495. Work will get underway on September 8th, to rehabilitate an 800-foot segment of the sanitary sewer system known as the Potomac Interceptor.

During construction, expect lane restrictions and reduced speeds eastbound on Clara Barton Parkway starting west of the I-495 ramp to just past the underpass. Access to the inner and outer loop of the Beltway/I-495 will remain available, however, drivers inbound on the parkway may experience some delays.

The Potomac Interceptor is a vital piece of infrastructure, transporting 60 million gallons of wastewater daily from Virginia, Maryland, and the District to the Potomac Pumping Station and the Blue Plains Advanced Wastewater Treatment Facility.

DC Water and its contractors will use a method called sliplining to repair the pipe by inserting a new, smaller diameter pipe into the existing larger line. This method reduces the need for major excavation, limits traffic impacts, and extends the life of the existing infrastructure.

This work is expected to continue through April and is part of an effort to rehabilitate the 78-inch sewer line before its condition deteriorates further. Completing the project now will help streamline construction activities and reduce future disruptions. A larger upgrade on the 54-mile Potomac Interceptor is planned for later this year.

Project Details

What: Potomac Interceptor Sanitary Sewer System Rehabilitation

Date: September 8th, and continuing through April 2026

Hours: 9:30 a.m. to 2:00 p.m.

Location: Clara Barton Parkway inbound prior to the I-495 ramp and just past the overpass

Impact: One lane closed and speed reduced to 30 mph through the construction zone

For more information

Click here for Project Factsheet.

Project email: potomacinterceptor@dcwater.com

Project Website: dcwater.com/potomacinterceptor

DC Water 24-hour Emergency: 202-612-3400