Built in 1910, the Ashbridges Bay plant is one of Canada’s oldest and largest WWTP, with a nominal treatment capacity of 818 ML/day. Initially, significant modifications were made to the existing grit building, effluent conduit, and channel. This was followed by extensive civil works including demolition, construction of a new bypass channel, and installation of 307 caisson foundations.

To improve the preliminary process areas and strengthen odour control, work on this contract included construction of a new screening building, loading bay building, and a 4-cell biofilter building. Equipment included new screens, pumps, conveyors, and compactors for handling and loading systems for screenings and grit.

With installation of new mechanical and electrical upgrades within adjacent areas, the project rendered the preliminary process areas compliant with the current electrical and fire protection standards. To perform the work, extensive planning and staging was required to maintain flows and keep the plant operational at all times.