CHESHIRE, CT – Excavation of the Northeast Boundary Tunnel (NEBT) in Washington, D.C., a joint-venture project valued at $580 million being constructed by The Lane Construction Corporation and its parent company, Webuild Group (formerly Salini Impregilo), is complete, as reported in a press release by Lane.
The Earth Pressure Balance Tunnel Boring Machine (TBM) “Chris” has completed the combined sewer outflow (CSO) tunnel being built to improve the water quality of the Anacostia River in Washington, D.C. The 23-foot inside diameter tunnel was successfully completed with about 27,700 feet excavated and 4,442 rings installed. The tunnel starts at RFK Stadium and ends at R Street, NW near downtown D.C.
The April 2021 hole-through milestone at the R Street shaft comes almost one year after Chris reached the W Street shaft, the first and only in-line shaft that the TBM crossed during its 26,700-foot-long drive beneath Washington, D.C.
The project is the largest component of the Clean Rivers Project, a greater initiative being led by DC Water, which will provide a complete system where sanitary and storm water from local jurisdictions is treated before being discharged into the Anacostia and Potomac Rivers. The $2.7 billion project to reduce CSOs in D.C.'s rivers is one of the largest infrastructure overhauls in the city's history. In addition to massive underground tunnels, the project also features large-scale green infrastructure projects to hybridize stormwater management.
Once the project is fully completed, the NEBT will increase the capacity of the existing sewer system to help manage flooding due to weather events, a problem the District has been experiencing for decades. Construction within the NEBT is expected to be finished by 2023.
The Anacostia River Tunnel project, the first component of the Clean Rivers Project, was also constructed by the Lane-Salini Impregilo joint-venture team. Since the service of the Blue Plains and Anacostia River Tunnels began in March 2018, SCOs to the Anacostia River have seen a 90 percent reduction, according to D.C. Water.
Just this past week, Lane lowered TBM “MudHoney” into a shaft in Seattle to start excavating the storage tunnel for the Ship Canal Water Quality Project in Washington. It’s another project currently being developed by Lane in the clean water sector that, too, will prevent millions of gallons of polluted stormwater and sewage from entering the local water resources each year.
