Mayor Muriel Bowser led the ceremonial blessing with a bottle of DC tap water, symbolising the District’s commitment to cleaner waterways and marking the beginning of Mary’s journey beneath the Potomac River.
“The DC Clean Rivers Programme plays such an important role in ensuring that we are the safe, clean and beautiful city that we are today,” said Bowser. “Whenever you make this type of investment in world-class infrastructure, that’s an investment in our collective future, it’s an investment in safe neighbourhoods and clean, swimmable waterways, and it’s an investment in our position as a beautiful waterfront city.”
TBM Mary will dig the northern leg of the tunnel, and TBM Emily – scheduled to arrive before the end of the year – will excavate the southern leg. The 6.4m-diameter Herrenknecht TBMs are named after abolitionist Mary and Emily Edmonson who attempted a daring escape from slavery via the Potomac River in 1848.
Together, they will construct the 8.9km Potomac River Tunnel, designed to prevent nearly one billion gallons of combined sewage and stormwater overflows from entering the Potomac River in an average year of rainfall.
DC Water CEO and general manager David Gadis said the ceremony celebrated not just a machine, but a movement.
“The Clean Rivers Program has been a game-changer for our city. We’ve watched the Anacostia River come back to life, and now, with Mary leading the way, we’re turning our focus to the Potomac. This tunnel is one of the final pieces of a legacy that will leave our rivers cleaner, our communities healthier, and our future brighter,” he said.
