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 repair efforts underway:

Containment Efforts

• No overflow from the pipe was reported today.
• The pump installed at the collapse site is effectively managing wastewater levels within the sinkhole and preventing overflow.
• Wastewater continues to be pumped out and discharged further downstream into the Potomac Interceptor.
• Potential overflow risks remain due to increased inflows from snowmelt, peak wastewater periods, and periodic pump clogs.
• On-site containment measures and bypass pumping operations continue to   successfully limit the risk of overflow.

Cleaning Efforts

• Active removal of blockages from the collapsed pipe is ongoing.
• Large rocks and boulders that entered the pipe during the collapse are too big for vacuum equipment, presenting significant challenges.
• Manual removal of rocks is necessary, requiring personnel to enter the access pit with live flow of wastewater.
• CCTV inspection is planned to better determine the extent of the rock dam and blockage inside the damaged pipe.
• 3D LiDAR scanning is planned to assess the structural integrity of the pipe around the damaged pipe.
• These measures are critical to confirm the integrity of the adjacent pipe sections prior to restoring full flow and reducing the risk of additional failures.

Pumping Operation

• Bypass pumps continue to operate stably with periodic maintenance required due to clogs from wipes and improperly disposed fats, oils, and grease.
• A secondary access point is being constructed upstream of the collapse for improved wastewater pumping flexibility.
• Additional pumps are being brought in to support operations from the new access point.
• These measures are intended to reduce flows through the collapse site and improve safety and efficiency during debris and rock removal activities.

Environmental Impact and Evaluation

• Limited overflows into the Potomac River have resulted in slight increases in coliform levels near Lock 10 over the past two days.
• More water sampling will be needed to establish a statistical sample size to draw conclusions and establish a trend.
• Independent environmental experts are conducting ongoing water quality monitoring. 
• DC Water continues to coordinate with federal, state, and local regulators on environmental evaluation and restoration planning.