Robinson Consultants Inc. was retained by Niagara Region to complete the rehabilitation planning, preliminary design, and detailed design for the Stamford Interceptor Trunk Sewer Rehabilitation Phase II. Niagara Region identified the need to rehabilitate the Stamford Interceptor Trunk Sewer (SITS) in the City of Niagara Falls based on historical CCTV inspections which showed that the segments are in very poor condition based on severe corrosion and exposed reinforcement as a result of hydrogen sulfide (H2S) in the pipe. The project scope included Phase II of the trunk sewer consisting of 1560m of 1050mm diameter reinforced concrete pipe, composed of 14 segments and 14 maintenance holes. The SITS runs parallel to the Ontario Power Generation (OPG) canal and along the new high traffic pedestrian trail (Millennium Recreational Trail). The objective of the project was to rehabilitate Phase II of the SITS and the associated maintenance holes using trenchless technology. As part of the trunk sewer rehabilitation project, the Region’s intention was to minimize disruption and closure of the Millennium Recreational Trail to reduce inconvenience to the public as well as reduce potential impacts to the existing OPG lands during construction.
Based on an evaluation of the potential trenchless rehabilitation options for the SITS, it was recommended that the Region proceed with the use of Cured-in-Place Pipe (CIPP) to rehabilitate the sewer due to its capability to resist H2S corrosion, provide a fully structural rehabilitation solution, and minimize impacts to flow capacity, and its suitability for 1050mm diameter pipe and commercial availability in the local market. Extensive coordination required during the design phase in order to minimize disruption and closure of the Millennium Recreational Trail to reduce inconvenience to the public as well as reduce potential impacts to the existing OPG lands during construction.
For the procurement process, it was recommended that the Region pursue a Request for Proposal (RFP) process versus a tender due to the complexity of the project, specialty nature of the rehabilitation work and the risks associated with working within the property. The objectives for the RFP are to retain a qualified and experienced rehabilitation contractor with a well-planned approach and methodology to complete the work.