Potomac River Tunnel Project Groundbreaking

The team broke ground recently on the Potomac River Tunnel (PRT) Project. Schnabel would like to thank DC Water for the opportunity to support the ongoing DC Clean Rivers Program over the past 14 years. We look forward to working with DC Water, CBNA and Halmar on the PRT project!

The PRT project includes an 18-foot-diameter, 5.5-mile-long deep sewer tunnel, shafts, drop structures and diversion facilities. Due to the stratigraphy of the tunnel alignment and schedule the PRT will be excavated with two tunnel boring machines: one for soft ground for the southern reach and another for rock the northern reach. The southern reach will eventually tie-in to the Anacostia River Tunnel System at the existing Bolling Airforce Base shaft. Connection of the PRT tunnel to the Anacostia River Tunnel System will be made at depth while flow in the existing system is maintained.

When completed, the PRT project will capture combined sewer overflows (CSOs) and convey them to the Anacostia River Tunnel System and ultimately to the Blue Plains Advanced Wastewater Treatment Plant. Set for completion in 2030, the PRT project will reduce CSOs to the Potomac River by 93%, enhancing water quality and aesthetics.

As part of the larger DC Clean Rivers Project, the Potomac River Tunnel will join over 18 miles of deep tunnels constructed to date on this program, that will increase the capacity of DC Water’s sewer system, reduce chronic flooding and reduce CSO’s discharge into the Anacostia and Potomac Rivers. This project showcases the benefits of innovative tunnel engineering on urban infrastructure.

About the project

The PRT will join over 18 miles of deep tunnels constructed to date on this program, that will increase the capacity of DC Water’s sewer system.