Crews also reach a major milestone near Dulles International Airport as the next phase of repairs begins this week

DC Water has completed the first major step in emergency repairs to a 175-foot section of the Potomac Interceptor near Pennyfield Lock in Potomac, Maryland. Crews added a new, stronger lining inside the pipe after inspections found serious wear and damage.

The work is part of ongoing repairs to 1,700 linear feet of pipe near Pennyfield Lock. This section was prioritized for repair because inspections found significant damage inside the pipe. Work began on Friday to apply geopolymer, a concrete-like material, inside the pipe. With the new lining complete, crews are preparing for the next phase of work for the remainder of the pipe segment.

“We are making strong progress on these repairs while working as quickly and safely as possible,” said DC Water Interim CEO and General Manager Matthew Brown. “This work will strengthen a critical sewer line, reduce risk for nearby communities and help protect the Potomac River.”

The next step at Pennyfield Lock is to install a new pipe inside the existing one. Crews are preparing two access points where the new pipe sections will be put into place. Work is expected to begin late next month. The new pipe is designed to last 50 to 75 years before it shows signs of wear.

DC Water has also reached a major milestone near Dulles International Airport in Loudoun County, Virginia. Last week, crews completed work to add a concrete-like lining that strengthens the pipe. The next phase of repairs is expected to begin this week and will use cured-in-place pipe, or CIPP. CIPP is a flexible liner that is placed inside the existing pipe and then hardened to create a strong new layer inside the sewer line.

Repairing the pipes from the inside allows DC Water to strengthen the sewer line without digging up and replacing large sections. This approach reduces disruption for nearby communities.

These repairs are part of DC Water’s broader effort to inspect and rehabilitate the Potomac Interceptor, a 54-mile sewer line that carries wastewater from parts of Maryland and Northern Virginia to DC Water’s Blue Plains Advanced Wastewater Treatment Plant.

After a pipe failure in Cabin John, Maryland, earlier this year, DC Water expanded inspections across the system. Crews used advanced tools to check the pipe and identify the areas most in need of repair.

DC Water is also moving forward with repairs at Broad Run in Loudoun County, Virginia, and near the DC-Maryland border. Together, these projects help reduce risk, protect public health, and safeguard local waterways.

DC Water will continue working with regional partners, government agencies and nearby communities as repairs move forward.

For more information about the Potomac Interceptor and related repair projects, visit dcwater.com/potomacinterceptor.