CSO Long Term Control Program

In November 1997 the Rhode Island Department of Environmental Management (RIDEM) issued the final discharge permit to the City including time schedules associated with study work at the Washington Street and Wellington Avenue Combined Sewer Overflow (CSO) Facilities.

In November, 1999 the City entered into a consent agreement (RIA-292) with the RIDEM regarding a plan to address the City's CSO Control Program. As required by the consent agreement the City submitted three Technical Memorandums (TM) that would be used to develop a detailed scope of work to develop a CSO Control Program in compliance with RIDEM and USEPA CSO policies.

Between 2000 and 2004 the RIDEM and City discussed the approach for the CSO Control Program. In July 2004 the RIDEM approved the Request for Proposals prepared by the City for engineering services associated with the development of the City's CSO Control Program. The CSO longterm control plan will be developed as a phased approach.

After RIDEM approval, the City Council awarded the contract to EarthTech in November, 2004. The program would initially address the Wellington Avenue CSO Facility as it was prioritized due to the USEPA designation of King Park Beach as a Flagship Beach.

The Phase 1 Part 1 work consisted of the following tasks and the work was completed in October , 2005:

  • Data Collection/Field Investigations Flow Metering of service area to Wellington Ave CSO Facility
  • Identification and Prioritization of Catchement Areas
  • Thames Street Interceptor Manhole Inspections
  • Identified Work for Phase 1 Part 2

The work completed in Phase 1 Part 1 was submitted was submitted for review and approval by the RIDEM to proceed with the work associated with Phase 1 Part 2. Approval was received and EarthTech was authorized to proceed in February, 2006 with the following tasks:

  • Thames Street Interceptor TV Inspection
  • Flow metering in Catchement Area 6
  • Hydraulic Model Evaluation
  • Windshield Surveys
  • The following field work in the prioritized Catchement Areas 1, 3, & 4
    • Flow Isolation/ Follow up CCTV
    • Manhole Inspections
    • House to House Surveys
    • Smoke Testing
    • Dye Testing
  • Report on Results and Recommendations due to RIDEM January 31, 2007

The Phase 1 Part 2 report which contains recommendations for Phase 2 work was reviewed and approved by the RIDEM in May, 2007. The City authorized EarthTech to proceed with the Phase 2 work in July, 2007. Phase 2 uses the field work from Phase 1 to identify longterm improvements to the sewer system in order to comply with the RIDEM and EPA CSO policies.

The primary goal is to eliminate overflows from the Wellington Avenue facility. The Phase 2 results and recommendation are due to be submitted to RIDEM for review and approval by February 28, 2009. The tasks in Phase 2 include the following:

  • Develop hydraulic computer model of collection system
  • Identify longterm plan for Wellington Ave. facility (i.e. sewer separation, storage and conveyance, etc)
  • Design for high priority sewer defects identified in Phase 1

The Phase 1 Part 2 report also identified work that the City could proceed with prior to final approval of the report. A Phase 1 Part 3 contract was awarded to EarthTech in November 2006 and included the following tasks:

  • Design for disconnection of 28 catchbasins and rehabilitation of 290 manholes
  • Smoke Testing for Area 6
  • House to House surveys -Area 6
  • Flow isolation -Area 6
  • Dye testing - Area 6

Future Phases of the CSO longterm Control Plan include the following:

Phase 3 will consist of the design of the longterm controls recommended in Phase 2 and approved by the RIDEM. Presently, it is anticipated the design and permitting tasks will take place in FY's 2010 and 2011.

Phase 4 will consist of the construction contract for the approved design of the longterm controls prepared in Phase 3. In addition there will be ongoing monitoring to verify the improvements do in fact control CSO's as proposed. It is anticipated construction would begin in FY2012.

Additional Work

The Phase 1 Part 2 report identified 28 catchbasins that were connected to the sanitary sewer system. These catch basins have been addressed as follows:

  • 3 catchbasins after further investigation were found not to be connected to the sanitarty sewer system.
  • 5 catchbasins were disconnected by EarthTech personnel
  • 1 catchbasin was disconnected by School Department personnel
  • 18 catchbasins have disconnection designed as part of Phase 1 Part 3 contract
  • 1 catchbasin requires additional review.

A construction contract (#08-001) was awarded in September, 2007 to disconnect 15 of the catchbasins that were included in the Phase 1 Part 3 contract. This work will be completed Spring, 2008.

City and EarthTech personnel also worked with the RIDOT to eliminate a cross connection between catchbasins on Memorial Blvd. West and the sanitary sewer system. The cross connection was eliminated in December, 2007.

Besides the work previously described as Phase 3 and Phase 4, the following related projects are proposed starting in FY2009:

  • Design and construction of catchbasin disconnects in Area 6
  • Construction of manhole rehabilitation
  • Construction of high priority sewer repairs
  • Thames St. Interceptor Improvements

The City is also working with property owners to disconnect roof drains, yard drains and sump pumps that have been identified as part of Phase 1 connected to the sanitary sewer system.

As of January 2008, the City has notified 539 property owners of which 186 have successfully disconnected a drain from the sanitary sewer system. City staff is working with the remaining property owners with disconnection.



The City of Newport, Rhode Island | City Hall | 43 Broadway | Newport, RI 02840 | 401-845-5300