On April 9, the District of Columbia Water and Sewer Authority (DC Water) named its massive tunnel boring machine (TBM), christened it with DC tap water, and prepared to send it underground to tunnel more than 4 miles along the Potomac at a depth of approximately 100 ft. The machine is more than 400 ft long and weighs more than 1,300 tons. It will dig the Blue Plains Tunnel, which is a portion of DC Water’s Clean River Project to significantly reduce combined sewer overflows (CSOs) and improve water quality in the District of Columbia.
D.C. Mayor Vincent C. Gray, EPA Regional Administrator Shawn Garvin, D.C. Councilmember Mary Cheh, DC Water Board of Directors Chairman Allen Lew and DC Water General Manager George S. Hawkins participated in the event at the Blue Plains Advanced Waste Water Treatment Plant.
“Much like her namesake, ‘Lady Bird’ will be performing important work for the long-term health of our rivers,” Hawkins said. “This tunnel will connect to another along the Anacostia River and another under Northeast D.C. that will reduce combined sewer overflows into the Anacostia by 98 percent.”
As in many older cities, about one-third of the District has a combined sewer system. Since the early 1900s, only separate sewer systems have been installed in the District. DC Water’s plan to significantly reduce CSOs to the Anacostia River is to build massive underground tunnels that will store the combined sewage and runoff during intense rainstorms and then slowly release it when the system has the capacity to treat it.
“Earlier this year, I unveiled the Sustainable DC Plan, a 20-year plan to make the District the healthiest, greenest, most livable city in the nation,” Mayor Gray said at the event. “The Clean Rivers Project goes a long way to providing sustainability for the region, making our waterways healthier and cleaner, while also addressing localized sewer issues from a century of urban development.”
DC Water’s TBM was named “Lady Bird” after Claudia Alta “Lady Bird” Johnson, First Lady and wife of President Lyndon B. Johnson. When her husband became president in 1964 she made it her mission to preserve and protect the environment. In 1964 she formed The Committee for a More Beautiful Capital, whose positive contributions are still visible today. She encouraged her husband to declare the Potomac River “a national disgrace,” which drew attention to the declining health of America’s waterways and was a catalyst for the eventual Clean Water Act of 1972.
Starting from two deep shafts at Blue Plains, the Lady Bird TBM will tunnel 24,200 lf up the Potomac River and to the Anacostia River, creating a metro-sized tunnel. That tunnel will also be instrumental in DC Water’s effort to reduce nutrient pollution to the Potomac River and Chesapeake Bay, and the innovative design saved $600 million over the alternatives.
Additional tunnels are also planned to reduce CSOs in the Potomac and Rock Creek sewersheds, although DC Water is also developing a green infrastructure pilot program. For more information, and specifications on the TBM and its route, please visit http://www.dcwater.com/news/presskits/tunnel or follow “Lady Bird” on Twitter @LadyBirdTBM.