Pawtucket Tunnel excavation completed

21 February 2024

CBNA-Barletta joint venture CB3A has completed the excavation and lining of the 3.6km Pawtucket Tunnel in Rhode Island.

The project is Phase III of RestoredWaters RI, Narragansett Bay Commission’s (NBC) Combined Sewer Overflow Abatement Program. TBM Chloe the Clean Water Cruncher was launched in summer 2022.

The deep rock tunnel, 38m below the surface, will store and transport storm-related combined sewer and stormwater overflow to NBC’s Bucklin Point Wastewater Treatment Facility for full treatment before discharge into Narragansett Bay. The tunnel has a storage capacity of 221.5 million litres.

In addition to the tunnel, the works include two launching/receiving shafts, four drop shafts to divert storm-related flow into the tunnel, and a 49m-deep tunnel pump station to transport flow from the tunnel to the Bucklin Point.

The next step in this phase of the CSO program will include the installation of the four drop shafts and outfalls.

“We are excited to complete this important milestone in the Phase III RestoredWaters RI project,” said NBC Chairman Vincent Mesolella. “We are continuing to see the positive results of the investments made through this project, including a significantly cleaner Narragansett Bay, reopening of shellfishing beds, and healthier waters for all Rhode Islanders for generations to come.”

RestoredWaters RI is the largest public works project in Rhode Island history. It will reduce storm-related sewage discharges by 93%. Phases I and II were completed in 2008 and 2014 respectively.