We’re excited to share the news that DC Water has launched the tunnel boring machine (TBM) Mary on the Potomac River Tunnel Project last week, marking the start of excavation for this major infrastructure initiative.

The first rotation of the cutterhead signals the transition from planning into active tunneling for the 5.5-mile tunnel system, which will significantly reduce combined sewer overflows into the Potomac River and improve long-term water quality in the region.

Gall Zeidler Consultants (GZ) is proud to be part of the Construction Management team for this critical project. Our services include design review, submittal review, and technical input into proposed solutions, as well as construction management and resident engineering services. GZ is currently providing on-site environmental compliance management services and will continue to support the project with resident engineering and inspection services as tunneling progresses.

Mary will excavate approximately 2.4 miles north from West Potomac Park to Georgetown University, with a second TBM, Emily, expected to complete the southern drive later this year.

GZ is honored to contribute to this transformative project alongside a strong team of partners delivering resilient and sustainable underground infrastructure solutions.

To learn more about GZ’s project involvement, please visit this site.

To read the full press release visit this link.

First turn of cutterhead signals the start of excavation for the Potomac River Tunnel Project. (Image Courtesy of DC Water)