Underneath DC's Clean Rivers Project

DC Water has three tunnel boring machines deployed on its $2.6 billion project to address combined sewer overflows
Underneath DC's Clean Rivers Project
A look inside the Anacostia River Tunnel which will stretch for more than 12 miles and be bored at depths of 100 to 125 feet below ground with finished inside diameters ranging from 20 to 23 feet. It is designed to capture and store combined sewage, reducing the District’s discharge to the Anacostia River by 96 percent, based on precipitation averages.

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The District of Columbia has three monster tunnel boring machines doing work beneath the ground as its Clean Rivers Project marks the halfway point in its 20-year plan.

The Clean Rivers Project includes the construction of multiple tunnels to capture combined sewer overflows and improve the quality of the Anacostia and Potomac rivers and Rock Creek.

“It’s required by federal statutes for us to address the combined sewer overflow problem here in the District of Columbia,” says Clean Rivers Project Director Carlton Ray. “We developed a 20-year plan in 2002 and it was accepted by the U.S. Environmental Protection Agency, the Department of Justice and other folks and began in 2005.”

The Anacostia River Tunnel System portion of the program will stretch for more than 12 miles and be bored at depths of 100 to 125 feet below ground with finished inside diameters ranging from 20 to 23 feet. The tunnels will be designed to capture and store combined sewage, reducing the District’s discharge to the Anacostia River by 96 percent, based on precipitation averages.

“We’re currently about halfway through the program,” Ray says. “We’re on schedule and on budget right now, so we’re doing quite well.”

The machines
The first tunnel boring machine to go online for DC Water was Lady Bird, a 26-foot-diameter, 442-foot-long machine that can tunnel an average of 125 feet a day.

 “We’ve gotten her over that several times,” says Ray. Lady Bird, which was christened on April 9, 2013, is named after Claudia Alta Taylor “Lady Bird” Johnson, the First Lady of the United States from 1963 to 1969. The machine began tunneling on July 29, 2013.

Lady Bird is excavating the Blue Plains Tunnel, which begins at the Blue Plains Advanced Wastewater Treatment Facility and goes north along the Potomac River toward the Anacostia River. It will then extend under the Anacostia beyond Poplar Point.

“She has mined approximately 20,000 feet out of a total of over 24,000 feet and she’s on schedule,” Ray says.

A second tunneling machine has been procured for the Anacostia River Tunnel. Slightly shorter than Lady Bird, Nannie was named after educator and civil rights activist Nannie Helen Burroughs. Nannie will begin excavation by the middle of this summer. Nannie is 26 feet in outside diameter, is 350 feet in length and will go a tad slower than Lady Bird, averaging about 100 feet a day.

The third tunnel, the First Street Tunnel, will be excavated by the program’s newest machine, Lucy, which was christened in April. Lucy has a 23-foot diameter and is 350 feet in length and will proceed at about 50 feet a day. The new machine will also begin excavation in mid-summer.

“She’s a refurbished tunnel boring machine, but all her main parts have been replaced,” Ray says. “This is a fast-tracked project for us, a fairly short project with it being less than a half-mile in length.”

Herrenknecht AG in Schwanu, Germany manufactured all three of the tunnel boring machines.

“They’re amazing pieces of equipment,” Ray says. “Lady Bird has been extremely active and very busy. She’s mined about 80 percent of the Blue Plains Tunnel and it’ll be exciting to see the other two getting to work soon.”

DC Water has contracted with three design-build teams who are responsible for designing, procuring and operating the machines to complete each of their respective projects.

Doing the work on the Blue Plains Tunnel is the joint venture of contractors Traylor Brothers-Skanska-JayDee. A joint venture of Impregilo-Healy-Parsons will build the Anacostia River Tunnel with Nannie and the joint venture of Skanska-JayDee will build the First Street Tunnel.

Next half of the project

While the project is at its halfway point, Ray says there is still plenty of work that needs to be done. This fall, DC Water plans to begin the procurement phase for a new tunnel called the Northeast Boundary Tunnel, which will be a design-build project just like the other tunnels.

“It’s going to be between 28,000 and 29,000 lineal feet and it’ll be about 26 feet finished inside diameter,” Ray says. “That one has a completion date of 2022 and somewhere between the price range of $500 and $600 million dollars.”

DC Water is also looking at the Long Term Control Plan’s Potomac River projects as well. These include the Potomac and Rock Creek Tunnels. These would serve the Kennedy Center and Watergate, but they are still a number of years away, Ray says.

DC Water is investigating whether green infrastructure can be used instead of gray infrastructure on those two tunneling projects. Green solutions are already being put into place in parts of the District’s service area.

The community

DC Water is doing as much as possible to keep community members up to date on what is happening with the Clean Rivers Project through biannual newsletters, meetings with local newspapers and meetings with advisory neighborhood committees.

“Both Lady Bird and Nannie are also active on Twitter and we do a lot of things on Facebook and our website to keep our customers updated,” Ray says. “We meet with civic associations to talk about the project, the importance of the project and what issues they might experience due to the project.”

The community was involved in naming the third tunneling machine. DC Water had an online survey where residents could select between three names for the machine — Lucy, Mary and Anna.


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