DC Water is investigating a sanitary sewer overflow from the Potomac Interceptor sewer line in the C & O Canal National Historical Park in Montgomery County after wastewater was observed exiting the pipe.
According to the Montgomery County Department of Emergency Management and Homeland Security, “DC Water is investigating a sanitary sewer overflow near the C&O Canal in Montgomery County. Drinking water is NOT affected, but residents may notice an odor in the area. Crews are working to contain and repair.”
Crews and contractors have been mobilized to contain the overflow, assess damage, and begin repairs, with the affected pipe located near Clara Barton Parkway just east of the Interstate 495 interchange, where the right inbound lane has been closed as a precaution.
The overflow is expected to reach the Potomac River, though officials said DC Water’s drinking water system is not affected and the incident is downstream from the Washington Aqueduct’s intake points. DC Water warned that untreated sewage can pose health risks if contacted and advised people to avoid the area and follow safety precautions; nearby residents may notice odors, and impacts to park trails and parking areas are possible as emergency measures continue and repair timelines are determined.
We are investigating a sanitary sewer overflow (SSO) from the Potomac Interceptor in Montgomery County, MD. Crews are on site to contain the overflow and begin repairs. Drinking water is NOT impacted. Details: https://t.co/bagpR6rAbi #DCWater pic.twitter.com/4YYfZtELTy
— DC Water (@dcwater) January 20, 2026
