On November 3rd, DC Water celebrated a major milestone in the Potomac River Tunnel Project with the ceremonial blessing of Mary, the tunnel boring machine that will dig the northern leg of the tunnel. The event at West Potomac Park marked the start of the tunnelling of this key phase of DC Water’s Clean Rivers Program.

Mayor Muriel Bowser led the blessing, joined by DC Water CEO David L. Gadis, Board Chair Dr. Unique N. Morris-Hughes, and other District leaders including Dr. Mousa Wone, DC Water Vice President and Chief Engineer. Mary and her sister TBM Emily which will dig the southern leg later this year are named after abolitionists sisters Mary and Emily Edmonson, who attempted a daring escape from slavery via the Potomac River in 1848. The two TBMs will construct the 5.5-mile tunnel, designed to intercept nearly one billion gallons of combined sewage and stormwater annually.

Our team had the privilege to attend the event: Area Manager Virginia, Thomas Martin and our senior Tunnel Engineer, Jared Clark were on-site to witness this historic moment.

Once completed in 2030, the tunnel will reduce overflow events from 74 to just four per year and cut overflow volume by 93%, helping keep the Potomac River cleaner and healthier.

GZ is proud to be part of the Construction Management team of this critical project. Our services include design review, submittal review and technical input into the proposed solutions and construction management and resident engineering services. GZ is presently providing on-site environmental compliance management services and will provide resident engineering and inspection services when tunneling starts.

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

To read the full press release visit this link.

Inauguration of the TBM Mary for the Potomac River Tunnel on November 3rd.