Oct 22, 2020

Rhode Island Storm Water Tunnel Underway

The Narragansett Bay Commission’s CSO Phase III tunnel will divert and treat storm water and sewage from Pawtucket and Central Falls.


storm water management

The final stage of a massive storm water runoff and sewage collection and treatment project was set in motion by the Coastal Resources Management Council (CRMC) at an Oct. 13 online meeting. 

Several issues need to be resolved, however, including where to dispose of 800,000 tons of pulverized rock and sediment, according to ecoRI.

The Narragansett Bay Commission (NBC), Rhode Island’s largest wastewater treatment operation, manages the combined sewer overflow (CSO) system. This CSO system is credited with significant pollution reduction in upper Narragansett Bay. 

CSO Phase III will divert, store, and treat up to 58.5 million gallons of storm water and sewage from Central Falls and Pawtucket before it is discharged into the Blackstone and Seekonk rivers, reported ecoRI.

Final plans have yet to be completed and submitted to CRMC. According to ecoRI, the project will have a tunnel pump station, four drop shafts, a tunnel odor-control facility and two additional treatment clarifiers will be built at Bucklin Point.

Structures on nine properties in East Providence and Pawtucket will be demolished to prepare for construction.

The Pawtucket tunnel is expected to take five years to complete and tunnel boring is scheduled to begin in two years. The project is the first of four segments for Phase III. According to ecoRI, additional connections and segments will be completed through 2041 and the work will include sewer connections, a smaller tunnel link, additional wastewater storage and green storm water infrastructure.

The $548 million Pawtucket tunnel project received a loan covering half the cost from the U.S. EPA and the Rhode Island Clean Water State Revolving Fund and other programs will also finance a portion of the project costs.

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