
Work continues on the Potomac Interceptor, a section of which collapsed on January 19, along Clara Barton Parkway and the I-495 interchange and C & O Canal Historical Park causing a sanitary sewer overflow.
A bypass system established five days after the overflow occurred continues to successfully divert wastewater around the collapse site and back into the Potomac Interceptor further downstream. ...

DC Water is taking emergency measures with the immediate and ongoing closure of all northbound lanes of 14th Street between L Street NW and Thomas Circle, due to the imminent risk of collapse posed by an abandoned, century-old, brick-lined sewer tunnel beneath the roadway.
DC Water and its contractors continue to make progress constructing new access points to the Potomac Interceptor, one upstream of the damaged section, and an additional entry downstream to divert more wastewater flow from the pipe. These access points will allow crews to install a bulkhead, blocking flow in the pipe upstream of the collapsed area, keeping the site as dry as possible so crews can ...
DC Water is releasing new findings regarding the environmental impacts following the January 19, collapse in a section of the Potomac Interceptor. Based on flow monitoring data collected before and after interim bypass pumping was activated, DC Water estimates approximately 243 million gallons of wastewater has overflowed from the collapse site.
Update on Extended Repairs, Safety Measures, and Water Quality Monitoring
Overnight CCTV inspection of the Potomac Interceptor revealed the blockage inside the collapsed sewer line is far more significant, showing a large rock dam stretching approximately 30 feet downstream of the original failure.
DC Water and its contractor are working to clean debris from a damaged section of the Potomac Interceptor, a sanitary sewer line that collapsed on January 19, along Clara Barton Parkway and the 495 interchange and the C & O Canal National Historical Park. While limited overflows occurred earlier in the week, no overflows from the site were reported today. Here is an update on the cleaning and ...
Potomac Interceptor Overflow Update
Tuesday, February 3, 2026
Work to clean and repair the damaged section of the Potomac Interceptor continues, though progress is being slowed by large boulders and rocks inside the pipe. Meanwhile, increased flow from groundwater infiltration attributed to snowmelt, along with periodic clogging of the bypass pumps, at times, resulted in minor overflows near the ...

Cleaning efforts continue today on the Potomac Interceptor, to remove debris and obstructions inside the damaged section of the sewer line. The 72-inch pipe collapsed two weeks ago along Clara Barton Parkway and the 495 interchange and the C & O Canal National Historical Park in Montgomery County, Md. Here is an update on the ongoing work.
Potomac Interceptor Overflow Update
Monday, February 2 ...
DC Water and its contractor are working to clean out the damaged section of the Potomac Interceptor, a sanitary sewer line which overflowed January 19, along Clara Barton Parkway and the 495 interchange and into the C & O Canal National Historical Park. Below is an update on the work being done and progress to date.
Potomac Interceptor Update
Sunday, February 1, 2026
Containment
- Overflow from the ...
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The overflow remains contained for now, with no overflows ...
