New DC Water project will improve the health of the Potomac River

Potomac River
April 16, 2021

DC Water is beginning a project in Georgetown to provide the area with separate pipes for stormwater and for sewage. Called sewer separation, it keeps stormwater from entering the combined sewer system, which can overflow during rain events due to the larger volume. 

Sewer separation is just one component of the plan to mitigate combined sewer overflows to the Potomac River, and is part of the larger Clean Rivers Project that is cleaning up all three waterways in the District. 

In the Potomac River sewershed, DC Water will use a multifaceted approach to reduce combined sewer overflows (CSOs), which contribute harmful bacteria, trash and other pollutants to the river. In addition to constructing a tunnel, DC Water is using sewer separation to reduce overflows from two CSO outfalls. 

Commenting on the project, DC Water CEO and General Manager David L. Gadis, said, “DC Water’s sewer separation project in Georgetown is an important step in improving the health of the Potomac River. When the Potomac River Tunnel is completed by 2030, these two projects will reduce combined sewer overflows to the river by 92 percent.”

The work includes installation of new sanitary sewers, storm water lines, manholes, sewer laterals, cleanouts and catch basins. DC Water will also relocate existing water mains at two sites along Wisconsin Avenue and 31st Street, NW. Additionally, the existing sewer regulator along the 48-inch Upper Potomac Interceptor will be modified. That work will take place on Water Street, NW, but all work is south of the C&O Canal. Construction begins this May and is slated for completion by September 2022. 

DC Water is hosting a virtual Community Meeting on April 20, 2021 to provide an overview of the project, the construction schedule, and what to expect during construction. Meeting details follow:

Date/Time: Tuesday, April 20, 2021 at 6:30 p.m.
Join the meeting at:
Dial-in option (audio only): 1-301-715-8592 Webinar ID: 817 4194 2834

For more information and a map of the three construction sites, see