Montgomery County MD: Sewer Pipe Burst Releases 900K Gallons of Sewage

A major sewage spill into the Potomac River, originating from a collapsed section of the Potomac Interceptor sewer line in Montgomery County, Maryland, continues to raise environmental concerns and draw political scrutiny. The incident, which began on January 19, 2026, has released an estimated 240 million to 300 million gallons of untreated wastewater into the river, according to reports.

The rupture occurred in a 72-inch diameter portion of the Potomac Interceptor, a critical component of the District of Columbia Water and Sewer Authority (DC Water) system. The interceptor carries wastewater from communities in Virginia and Maryland to the Blue Plains Advanced Wastewater Treatment Plant in Washington, D.C. The aging infrastructure, largely constructed in 1962, is responsible for transporting sewage from Dulles International Airport and surrounding areas.

Initial estimates suggest approximately 40 million gallons of raw sewage have been flowing into the Potomac River each day since the collapse – equivalent to filling roughly 66 Olympic-size swimming pools. Dean Naujoks, the Potomac Riverkeeper, described the situation as dire, stating Oh, my god, the smell is horrific. It’s such high concentrations of sewage that just grabbing a sample is a public health risk. Officials have cautioned the public to avoid the affected areas and to wash thoroughly if exposed to the water.

DC Water has been working to mitigate the spill by installing a bypass system near Lock 10 of the Chesapeake and Ohio Canal National Historical Park. This system diverts wastewater through a contained section of the canal, carrying it 2,700 feet before rejoining the Potomac Interceptor at an undamaged point. The bypass has since been enhanced with additional pumps to increase capacity.

Repair efforts are complicated by a rock dam that is currently blocking access to the damaged section of the pipe. DC Water plans to install a steel gate to isolate the affected area, allowing crews to pump out remaining wastewater and begin excavating the rock dam. The full extent of the damage will not be known until the dam is removed. Emergency repairs are expected to take between four and six weeks, with a longer-term rehabilitation phase of the C&O Canal anticipated to last between nine and ten months.

The incident has sparked political debate. Former President Donald Trump, in a post on Truth Social on February 16, 2026, blamed Maryland Governor Wes Moore for gross mismanagement of local Democrat leaders, alleging a failure to request federal emergency assistance. However, Maryland officials have stated they are actively collaborating with the Environmental Protection Agency (EPA) on cleanup and repair efforts.

The Potomac River sewage spill is being described as potentially one of the worst environmental disasters in the region’s history. The University of Maryland School of Public Health has characterized the spill as one of the largest in U.S. History. The impact on the river’s ecosystem and potential public health risks are still being assessed.

The affected area is approximately 5 miles (8.0 km) upstream from Washington, D.C. The Potomac Interceptor sewer line is partially located within the Chesapeake and Ohio Canal National Historical Park, adding another layer of complexity to the repair process and raising concerns about the canal’s long-term health. The Washington Suburban Sanitary Commission (WSSC) manages a section of the Potomac Interceptor in the Maryland suburbs, while DC Water is responsible for the majority of the infrastructure.

The collapse of the Potomac Interceptor highlights the challenges facing aging infrastructure in the United States. The incident underscores the need for investment in maintaining and upgrading critical systems like sewer networks to prevent future environmental disasters and protect public health. The long-term consequences of this spill, and the effectiveness of the ongoing repair and rehabilitation efforts, will be closely monitored by environmental agencies and local communities.