DC Water activated a bypass system Saturday evening to contain wastewater overflows caused by a collapse in the Potomac Interceptor sewer line along Clara Barton Parkway in Montgomery County and within the C & O Canal National Historic Park.
The problem began late Monday, when a 72-inch section of the sanitary sewer line collapsed, sending millions of gallons of wastewater into the surrounding area. The Potomac Interceptor normally carries up to 60 million gallons of wastewater per day from parts of Maryland and Virginia to the Blue Plains Advanced Wastewater Treatment Plant.
Crews completed the installation of six high-powered pumps earlier Saturday, allowing wastewater to be rerouted around the damaged section of pipe. Each pump can move up to seven million gallons of wastewater per day, diverting flow from upstream of the collapse into an isolated section of the canal and then back into the sewer system downstream. Engineers on site confirmed the system is capturing most of the wastewater and is expected to bring flows back to normal levels through the evening, helping prevent additional overflows into the park and the Potomac River. The bypass also allows excavation and repair work to begin at the collapse site.
DC Water had initially anticipated activating the pumps Monday evening, January 26, with full operation by Tuesday, January 27, but crews were able to finish construction and bring the system online earlier than expected ahead of the winter storm. Officials continue to urge the public to follow posted warning signs and avoid contact with any overflow, noting that exposure to raw sewage can cause illness. There is no impact to drinking water, as the sewer and drinking water systems are separate and the overflow occurred downstream from the Washington Aqueduct intakes at Great Falls.
The C & O Canal Towpath remains open and no overflow has reached the towpath, though odors may be noticeable in nearby areas. As repairs continue, one inbound lane of Clara Barton Parkway remains closed just east of the I-495 interchange.
