Potomac Tunnel project underway: CBNA, Halmar, COWI, & Hatch join forces

February 15, 2024

Washington D.C. - CBNA, Halmar, COWI, and Hatch proudly announce a partnership aimed at providing unparalleled expertise in tunnel construction and innovative solutions to DC Water. Together, the group has secured a design-build contract for the construction of the Potomac River Tunnel (PRT).

The $819 million PRT contract represents a pivotal moment for DC Water, marking the largest-ever awarded contract by the Authority. The 5.5-mile-long tunnel will serve as a crucial mechanism to control combined sewer overflows (CSOs) into the Potomac River, significantly enhancing the water quality of this vital natural resource. This project is an integral component of the broader Clean Rivers Project, a $2.99 billion initiative aimed at improving water quality in the Anacostia and Potomac Rivers and Rock Creek while strengthening the sewer system's capacity.


Steven Kramer, COWI Senior Project Director, said:
“COWI will lead the design of the tunnel and adits, and provide geotechnical support for the entire project. We leverage our domestic and global personnel to bring experts in multiple disciplines. Our team began working in late 2023 and has already delivered several key early lead items which has enabled the design and build team to begin construction.  Working with CBNA-Halmar and Hatch through the tender process and now the actual project has been very exciting and gratifying for our engineers. In a design and build project, it is always rewarding to see our design being implemented especially on such a critical project as the Potomac River Tunnel.” 

Bruce MacKay, Hatch’s Managing Director for Water, noted:

"At Hatch, we believe in partnerships that align with our core values of sustainable progress and community enhancement. This collaboration exemplifies our dedication to pioneering designs that ensure a healthier, more sustainable future for the District of Columbia and its residents. Working with our partners, Hatch will be responsible for overall design management as well as the detailed design of underground works, including support of excavation and concrete structures.”


Traversing beneath and along the Georgetown waterfront, West Potomac Park and the National Mall, the 18-foot-diameter tunnel will extend to Hains Point, ultimately connecting to the existing Anacostia River Tunnel. Utilizing advanced tunnel boring machines, the construction will navigate various ground conditions, ranging from soft ground to rock. The surface and subsurface challenges will require precise engineering and the use of innovative construction techniques by the project partners.

Commencing in 2024 and slated for completion in early 2030, the project's impact will be significant. Once operational, the PRT is projected to curtail combined sewer overflows (CSOs) to the Potomac River by an impressive 93 percent during typical rainfall years, solidifying its pivotal role in enhancing environmental sustainability for the region.

For detailed insights into the Potomac River Tunnel Project, please visit dcwater.com/PRT.

About Hatch

Hatch is a project delivery, engineering, and professional services firm. Whatever our clients envision, our teams can design and build. With over six decades of business and technical experience in the mining, energy, and infrastructure sectors, we know your business and understand that your challenges are changing rapidly. We respond quickly with solutions that are smarter, more efficient, and innovative. We draw upon our 10,000 staff with experience in over 150 countries to challenge the status quo and create positive change for our clients, our employees, and the communities we serve.

Find out more on www.hatch.com.

For more information about Hatch, please contact:

Lindsay Janca

Global Director, Public Relations

Tel: +1 905 403 4199

Email: media@hatch.com

About COWI

COWI is a consulting group headquartered in Denmark with more than 7,500 employees. Together with our customers, we work to shape a sustainable and liveable world by co-creating sustainable solutions that improve the quality of life for people today and many generations ahead. Our range of services includes engineering, architecture, energy and environment. With a strong presence in the Nordic region, the UK and North America and activities in more than 35 countries, we provide flexibility when supporting our customers in achieving their sustainability goals. To learn more about COWI, visit us at www.cowi.com.

For further information about COWI, please contact:  

Lorna Wharton Chart PR MCIPR

Leading Specialist, Press and Public Affairs