Broken Potomac Interceptor sewer line spills wastewater near Clara Barton Parkway, triggering lane closure and delays

Wastewater spill reported in C&O Canal parkland near I-495 interchange

A broken section of a major regional sewer line led to a sanitary sewer overflow in Montgomery County, Maryland, prompting traffic restrictions along the Clara Barton Parkway and raising public health and environmental concerns along the Potomac River corridor.

The overflow was identified on the evening of January 19, 2026, after wastewater was observed flowing from the Potomac Interceptor within the Chesapeake & Ohio Canal National Historical Park. The damaged segment is located close to the Clara Barton Parkway just east of the I-495 interchange. As a precaution, crews closed the right inbound lane near the incident area, with officials warning that commuters should anticipate delays, particularly during peak travel times.

Traffic impacts and public access restrictions

The lane closure affects inbound traffic on the Clara Barton Parkway near the Capital Beltway connection, a choke point for commuters traveling between Montgomery County and the District. In addition to roadway impacts, park amenities may be disrupted: nearby trails and parking areas along the parkway can be affected by emergency response activity and containment work.

• Right inbound lane closure in the affected segment near the Beltway interchange
• Potential delays for inbound Clara Barton Parkway traffic and Beltway-bound drivers
• Possible limitations to trail use and parking access within the adjacent park area

Containment, repairs, and what is known so far

Crews were mobilized to mitigate and contain the overflow as much as possible while the damage is assessed and repairs are planned. At the time of the initial public updates, no repair timeline had been provided.

The Potomac Interceptor is a high-capacity sanitary sewer system that conveys approximately 60 million gallons of wastewater per day from areas near Washington Dulles International Airport through Northern Virginia and Maryland to Washington, D.C. From there, flows are routed onward to the Blue Plains Advanced Wastewater Treatment Plant for treatment.

Environmental and health considerations

The overflow is expected to reach the Potomac River. Officials emphasized that the drinking water system is separate from the wastewater system and is not impacted by the incident. The overflow is also described as occurring downstream of the Washington Aqueduct’s intake location at Great Falls.

Untreated sewage can contain pathogens that may cause illness; people are advised to avoid contact with affected water or contaminated areas.

Guidance issued for anyone who may have come into contact with the overflow includes leaving the area, washing exposed skin thoroughly with soap and clean water, disinfecting affected items, avoiding consumption of potentially exposed food or water, and seeking medical attention if symptoms develop. Residents near the area may notice odors associated with the overflow.

Broader infrastructure context

The incident occurs as work in the Clara Barton Parkway corridor has been associated with sewer system inspections and rehabilitation activity in recent years, reflecting the operational sensitivity of the Potomac Interceptor and the challenges of maintaining large-diameter wastewater infrastructure that serves multiple jurisdictions.