CSO Project Construction

Combined Sewer Overflow (CSO) Construction

Construction related to Phase II of the Narragansett Bay Commission's Combined Sewer Overflow has been completed. For the history of the project, click here. For information on the Phase III stakeholders process, click here.

NBC's CSO Program is a federally-mandated water quality improvement project mandated by the 1972 Federal Clean Water Act, and will enable Rhode Island to meet the Department of Environmental Management policy to "elminate overflows from a three-month storm" (1.64 inches of rain in six hours). Phase I of the project included a deep rock tunnel that captures sewage overflows and transports the flow for treatment to the NBC's Field's Point Wastewater Treatment Facility. Phase II included two near surface interceptors along the Seekonk and Woonasquatucket Rivers to bring additional flow to the Phase I tunnel, a new storm drainage system in the Summit neighborhood, and a constructed wetlands in Central Falls.

 East Side | West Side

EAST SIDE


Hope Street (303.05/OF 027)

Project components:

  • 15,798 linear feet of new storm drains, ranging in size from 12” to 30” -- complete.
  • 6,000 linear feet of new drinking water pipes, ranging in size from 6” to 8” -- complete.
  • 111 drainage manholes  -- complete.
  • 136 catch basins -- complete.
  • Relocation/modernization of gas and water lines in coordination with National Grid and Providence Water -- complete.
  • Reconstruction and curb-to-curb repaving of all affected streets and sidewalks.
  • Pedestrian enhancements for Hope Street.

Completion: August 2013


North Main Street (303.06/OF 037 West)

Project components:

  • New storm drains -- complete.
  • New drinking water pipes  -- complete.
  • New catch basins --  complete.
  • New drainage manholes -- complete.
  • New river headwall -- complete.
  • Reconstruction and curb-to-curb repaving of all affected street and sidewalks.
  • Street enhancements, including making Smithfield Avenue a 2-way street

Completion: Spring 2014


5th Street to Glendale, from North Main to Summit (303.07/OF 037 North)

Project components:

  • New storm drains
  • New drinking water pipes 
  • New catch basins
  • New drainage manholes
  • Reconstruction and curb-to-curb repaving of all affected street and sidewalks

Completion: December 2014 


Colonial Road to 4th Street, from North Main to Summit (303.08/OF 037 South)

Project components:

  • New storm drains
  • New drinking water pipes
  • New catch basins
  • New drainage manholes
  • Reconstruction and curb-to-curb repaving of all affected street and sidewalks

Completion: January 2015


India Point Park (303.04/SCSOI Main)

Project components:

  • 7200-ft long near-surface interceptor along the Seekonk River from Richmond Square to Phase I tunnel (vicinity of India Street)

Completion: December 2014

 


 

WEST SIDE

Woonasquatucket River CSO Interceptor (303.03C WCSOI Main)

Project components:

  • 10,000 ft long near-surface interceptor along the Woonasquatucket River from Providence/Johnston line to the Phase I tunnel (near Calvery/Bath Streets)
  • Includes 21 jacking pits to service the mini tunnel boring machine (MTBM) and a 1800-ft deep-rock adit (>220 ftdeep) to connect to tunnel

Completion: Spring 2015