ALEXANDRIA, Va. —  AlexRenew, Alexandria’s wastewater authority, has completed construction of the Waterfront Tunnel, reaching another major milestone in its historic RiverRenew program by delivering critical infrastructure that will improve the water quality of Alexandria, Virginia’s local waterways.

The breakthrough moment occurred on March 13, when Hazel, AlexRenew’s tunnel boring machine, burst through a 100-foot-deep shaft south of Alexandria’s Oronoco Bay, marking a 2.2-mile journey 16 months in the making. Brown and Caldwell (BC) is proud to serve as Owner’s Advisor (OA) on RiverRenew, the largest infrastructure project in the city’s history.

“The collective efforts of our team to achieve this momentous milestone are nothing short of awe-inspiring. Their dedication and perseverance pave the way for a brighter future for the Potomac River.”

AlexRenew General Manager and CEO Justin Carl (in a press release)

To achieve this visionary project, Hazel and her crews worked around the clock to construct more than 2 miles of tunnel, made of over 15,000 concrete segments, and remove nearly 78,000 cubic yards of soil. Once in operation, the RiverRenew tunnel system will prevent over 120 million gallons of combined sewage from polluting the Potomac River, Hunting Creek, and Hooffs Run each year.

The system is expected to be fully operational in 2026, meeting a state mandate to improve water quality in the Potomac.

“The project will benefit the environment and the community for generations to come,” Brown and Caldwell Program Manager Kelvin Coles said.

About AlexRenew

AlexRenew is the wastewater treatment authority for Alexandria and parts of Fairfax County, serving more than 300,000 customers. Each year, the public utility treats approximately 13 billion gallons of wastewater before safely returning it to our waterways. AlexRenew is also implementing RiverRenew, the largest infrastructure project in the history of Alexandria.

About Hazel the TBM

Hazel, AlexRenew’s tunnel boring machine, was named after Hazel Johnson, an environmental activist from Chicago, Illinois, who is considered to be the mother of environmental justice. Hazel, the TBM, was a critical contributor to the success of the team that is building the RiverRenew tunnel system, a $615 million initiative to prevent millions of gallons of sewage from flowing into the Potomac every year.

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