On the 14/01/22 the 10.3m Multi-Mode TBM, built by Herrenknecht for Narragansett Bay Commission's (USA) Pawtucket Tunnel Project, passed its Factory Acceptance Testing. The TBM - commissioned by the CB3A Joint Venture which includes CBNA (Civil & Building North America Inc.), Barletta Heavy Division, Inc. and AECOM for construction - is expected to arrive in Rhode Island in the Spring of 2022! NBC’s CSO Phase III involves construction of a 3.5 km-long and 9.14 m (30 ft) in diameter deep rock tunnel that will be driven by this machine along the Blackstone River in Pawtucket.
The Pawtucket Tunnel is designed to store the volume of the combined sewer overflows (CSOs) in Providence, Pawtucket and Central Falls. The stored volume will be pumped to the BPWWTF by the Tunnel Pump Station. The Tunnel Pump Station is being designed for a firm capacity of 27.3 MGD. Four main dewatering pumps will have a nominal rating of 9.1 MGD each. The combined capacity of all three main pumps will be 27.3 MGD. The fourth pump will serve as a standby. To accommodate a wide range of flow conditions, each of the four main pumps will be provided with a variable frequency drive (VFD).
Upgrades to the BPWWTF are required to improve performance of the secondary treatment to accommodate future tunnel pump out operations after wet weather events. The BPWWTF, located in East Providence (Ri), serves the 75-square mile Bucklin Point Service Area (BPSA), treating flow from all or parts of East Providence, Pawtucket, Central Falls, Smithfield, Cumberland, and Lincoln.
Phase III of the program (Phase III CSO Program), which began in 2016, is focused primarily on the Bucklin Point Service Area (BPSA) in the communities of Pawtucket and Central Falls. Its projected completion date is 2041.
The Phase III CSO Program has been subdivided into four sub-phases, as follows:
• Phase IIIA: Pawtucket Tunnel
• Phase IIIB: Upper BVI Relief Structure and OF-206 Sewer Separation
• Phase IIIC: Stub Tunnel to Control OF-220
• Phase IIID: West River Interceptor and OF-035 Sewer Separation
For further information please click here and us/37 for the tunnelbuilder archive, visit https://www.narrabay.com. 03/22.
