East Trunk Sanitary Sewer Rehabilitation

Growth within upstream areas continued to increase flows to the east trunk and ultimately the G.E. Booth Wastewater Treatment Plant in Mississauga, Ontario. The rehabilitation of this trunk and operation as a storage facility will provide flexibility and additional system resiliency and was thus considered a critical project for the Region of Peel.

The project included a condition assessment of the upstream Energy Dissipation Chamber (EDC) and the abandoned section of the East Trunk, completed using CCTV, 360 camera and Faro 3D scanning. The data from the condition assessment provided the basis of the feasibility for rehabilitation or decommissioning.

The feasibility study was completed to determine the approach of achieving in-line storage for the Region. It evaluated four options including:

1. Replacement of the abandoned EDC with rehabilitation of the trunk sewer
2. A new storage system
3. Rehabilitation of the EDC and the trunk sewer
4. The complete decommissioning of the abandoned EDC and trunk sewer

The feasibility study was supported by the completion of the condition assessment, rehabilitation option assessment, hydraulic assessment, slope stability assessment, and permits and approvals assessment.

The conceptual design evolved from the evaluation of options identified in the feasibility study. The conceptual design included the evaluation of two storage systems, using tanks for storage and parallel pipes for storage with various operational options. The conceptual drawings featured four parallel 3,600mm storage pipes with flushing gates and a vortex drop structure, and two concrete tanks with water spray nozzles for cleaning/flushing and a vortex drop. The final recommendation to the Region of Peel was to construct the parallel pipe option.