DC Water said emergency repairs to the Potomac Interceptor have been completed after 55 days of continuous work, allowing wastewater flow to return to the pipe and bypass pumps to be shut off. Officials said the change caused water levels in the C & O Canal to drop quickly as diverted wastewater drained out, and crews have now begun environmental cleanup efforts that include flushing the canal with freshwater, clearing debris, removing muck, and excavating contaminated soil.
The collapse released an estimated 243.5 million gallons of wastewater and was described by the University of Maryland as one of the largest sewage spills in U.S. history.
According to DC Water, crews first mobilized after the January 19 collapse and installed an initial bypass pumping system within five days. The agency said overflows to the Potomac River were fully contained within 21 days, helping prevent about two billion gallons of wastewater from entering the river. DC Water also outlined the scale of the response, saying crews removed 10,500 gallons of rag-filled pump debris, hauled in 35 tons of gravel daily, and used 3,680 gallons of fuel per day to operate pumps and equipment.
With the emergency phase complete, DC Water said it is moving into a longer-term rehabilitation effort that will reinforce more than 2,700 linear feet of pipe through a slip-lining process. Environmental restoration will continue alongside that work, with brush and debris removal, soil excavation, and erosion control measures already underway. The agency said odors may remain strong near the mostly drained canal while cleanup continues over the next one to two months. Community meetings are scheduled for March 18 in Bethesda and March 19 in Alexandria to provide updates and gather public feedback.
