Its the Bergen Outfall Pipe Upgrade!
OHL USA, Inc., an OHL North America company, announces it has been awarded a $187 million joint venture contract (40% OHL USA, Inc., 40% Posillico Civil, Inc., 20% SELI Overseas USA, Inc.) by Suffolk County Department of Public Works to replace existing outfall pipe at the Bergen Point Waste Water Treatment Plant (WWTP) in Babylon, NY. This is the largest construction project in Suffolk County in several decades and OHL’s first project on Long Island, expanding OHL’s regional presence in the New York area. Construction started on February 8th, 2018 and will be completed by summer 2021.
The project includes the construction of a 14,200-foot, 120-inch inner diameter tunnel through a mixture of soft soil materials under the Great South Bay with the use of a tunnel boring machine (TBM). The tunnel will be constructed to replace the existing Prestressed Concrete Cylinder Pipe (PCCP) outfall pipe, which carries millions of gallons of treated wastewater, connecting the Bergen Point Wastewater Treatment Plant (WWTP) to the Barrier Island under the Great South Bay. The new tunnel will address the concerns of potential failure of the current pipe and has a longer lifespan.
The tunnel will be excavated and concurrently lined using precast concrete segment rings. The JV has selected a slurry TBM as the most effective and efficient means of tunnel excavation and elected to use 48-inch wide precast segment liners. The shaft construction will be divided into major work phases including site preparation, excavation of the launch shaft and installation of the new slurry TBM. Once the TBM is installed, tunnel excavation will proceed in four foot “pushes,” followed by the installation of the permanent tunnel lining. Additionally, the team will also complete ancillary work within the tunnel including the installation of new piping and valving, associated plumbing, HVAC, and electrical work.