Potomac Interceptor Repairs Update
February 28, 2026

• The bypass pumping system continues to divert wastewater around the collapse site and back into the Potomac Interceptor, preventing any overflows from reaching the Potomac River in nearly three weeks. The last time an overflow reached the river was 20 days ago, February 8.
• Crews continue to clean the pipe and progress is being made to remove the remaining muck, debris, and rocks inside.
• After cleaning, an inspection will be performed with CCTV cameras inside the pipe in preparation for the emergency repair to apply a geopolymer lining similar in strength to concrete.
• Work has begun on the environmental rehabilitation of the overflow areas and drainage channel, which will include debris clean-up, soil raking, stabilization of the soil and stream and other mitigations.
• Work remains on schedule to complete the emergency repair by mid-March.

Water Quality Sampling

DC Water is performing daily water quality sampling. It’s important to note that historically the E. coli levels in the Potomac and Anacostia rivers vary widely from day to day. This is reflected in recent sampling results with stormwater runoff from rain and snow impacting water quality. Fluctuations in water quality are influenced by factors such as weather events, river flow, runoff, pollutants, releases of combined overflows, and other sources discharging into waterways.

Given these variables, measurements taken much further downstream cannot be attributed solely to this incident.

For the Potomac River, historical water quality data shows E. coli levels may vary from a range as low as 10 MPN/100mL to as much as 5,000 MPN/100mL on a given day. A more detailed explanation is posted on the District Department of Energy and Environment (DOEE) website at doee.dc.gov/release/potomac-interceptor-update-and-faqs.

Below are the results of sampling during the period from February 16 – present. Past results may be found on our dedicated Potomac Interceptor Response page.