UPDATE: Potomac Interceptor Oveflow, Saturday, January 31
January 31, 2026
DC Water and its contractor continue work to mitigate the sanitary sewer overflow that occurred on January 19, from the Potomac Interceptor, along Clara Barton Parkway and the 495 interchange and into the C& O Canal National Historical Park. Below is an update on the progress.
Potomac Interceptor Overflow Update
January 31, 2026
Containment
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The overflow remains contained for now, with no overflows from the damaged pipe section for a third straight day.
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Pumping operations continue and the bypass is operating as expected.
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We have eight pumps running, which provides us excess capacity and redundancy.
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Some residual wastewater may still be in the creek bed, and the excavation work may release a small amount of wastewater into the creek bed.
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The risk of overflow is greatly reduced, however, the potential for dry and wet weather overflows will not be eliminated until full flow is returned to the sewer line.
Repair Efforts
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Site preparations continue for operations to begin clearing the blockage at the collapse site.
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Contractors today excavated and opened up another section of the Potomac Interceptor further downstream of the break.
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Once cleaning of the collapse site begins, some soil and debris loosened by the cleaning may flow downstream.
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The second location will allow another access point to capture this debris as part of the cleaning process.
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This work will continue on Sunday and it is expected to take several days to clean out the pipe and restore full flow, pending any unknown issues.
Environmental Cleanup and Review
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We have begun taking water samples for testing.
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Teams are in the process of surveying the area to develop a cleanup and restoration plan, which will be reviewed with our partner agencies at the federal, state and local level.
Impact of Snow Melt
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The C & O Canal section being used as a bypass has extra capacity that should be able to handle snow melt.
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With eight pumps operating, we also have additional pumping capacity should flow inside the PI increase.
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The C & O Canal section being used for the bypass is dammed at Lock 14, preventing any snowmelt upstream from entering the bypass section and impacting water levels.
