DC Water is working to repair and strengthen a 2,700-foot section of the Potomac Interceptor, a major sewer line along Clara Barton Parkway between the I-495 interchange and Lock 10 of the C & O Canal. The area includes a section of the interceptor that collapsed on January 19 causing more than 243 million gallons of sewer overflow into the Potomac River. After the failure, DC Water accelerated the rehabilitation which was previously planned but had not yet started. Once complete, the work will help protect the long-term reliability of a critical part of the region’s wastewater system.

Crews have started early construction activities, including site excavation, building access roads for construction equipment, and delivering new pipe materials needed for installation.

The Potomac Interceptor carries about 60 million gallons of wastewater each day from parts of Maryland, Virginia, and the District, to DC Water’s Blue Plains Advanced Wastewater Treatment Facility. Keeping this sewer line in good condition helps protect public health, the environment, and reliable sewer service for the region.

To complete the rehabilitation, DC Water and its contractors are using slip lining and temporary bypass pumping operations. Slip lining installs a new pipe inside the existing sewer line to strengthen and restore the system to like-new condition. Bypass pumping reroutes wastewater around the active construction area, allowing crews to complete repairs safely while maintaining uninterrupted sewer service. These methods reduce the extensive digging needed to replace the existing pipe and limits impacts to nearby roads, parkland, and surrounding communities.

DC Water expects construction to continue through February 2027. During that time, crews will rehabilitate both the 72-inch and 66-inch sections of the Potomac Interceptor in this area.

PROJECT UPDATES

July 2, 2026
DC Water to Continue Daily Potomac River Testing Through July 31 as Potomac Interceptor Repairs Continue

PROJECT DETAILS

WHAT

Repair and rehabilitation of a major sewer line along Clara Barton Parkway at I-495 near Rock Run

DATE

Late Summer 2026 to February 2027

HOURS

7 a.m. to 5 p.m.

LOCATION

Clara Barton Parkway Inbound Prior to the I-495 ramp to Lock 10 of the C & O Canal

IMPACT

One lane closure and reduced speeds of 30 mph through the construction zone

FOR MORE INFORMATION

Click here for the Project Fact sheet

Project email: potomac.interceptor@dcwater.com

Project Website: dcwater.com/potomacinterceptor

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