Client – City of Ottawa
Consultant – EGIS
Awarded Contract Value – $14M
Contract Timeline – July 2022 to November 2024
The Storm Sewer Trunk Rehabilitation Phase 2 project (Contract No. CP000504) involved the replacement and rehabilitation of a major storm sewer trunk between Saunderson Drive and Foley Avenue in Ottawa. The work was completed using open-cut trench construction methods and included the installation of a new 2,100 mm diameter Class 140D concrete storm sewer pipe.
The new trunk sewer was connected to existing storm infrastructure, including 2,900 x 1,950 mm and 2,200 x 1,600 mm corrugated steel pipe arch (CSPA) sewers. Grouted joints and concrete collars were used to ensure watertight connections. To maintain stormwater flow during construction, temporary bypass systems were implemented. These included flow restrictions, bulkheading, and bypass pumping to divert flow and maintain dry working conditions. Major elements of the work included:
- Installation of 2,100 mm concrete pipe, including custom bends and 45-degree 1,050 mm WYE fittings.
- Construction of large maintenance holes, including 3,810 x 3,810 mm and 3,000 x 1,500 mm structures, each equipped with safety platforms.
- Establishment of bypass connections at key locations (Sta 0+480, 0+160, and 0+019) to support phased construction.
- Execution of dewatering operations under a comprehensive groundwater management plan, which included the installation of piezometers and monitoring of settlement in adjacent properties.
- Subgrade improvements where necessary, including sub-excavation, installation of geotextile fabric, and placement of select materials to stabilize trench foundations.
- In addition to sewer works, Cavanagh also completed the roadbuilding, grading, earth excavation, and asphalt paving. As the general contractor, Cavanagh managed the concrete, utility, and landscape subcontractors to successfully complete the project.
