Ashbridges Bay Treatment Plant – Effluent Disinfection System

Location: Toronto, ON

The Ashbridges Bay Treatment Plant is Ontario’s oldest and largest wastewater treatment plant and has been in operation since 1917. The Effluent Disinfection System project comprises of construction of a new major disinfection facility, including a three-story building housing state-of-the-art UV disinfection equipment and chemical systems. Incorporated within the building are underground service tunnels and effluent conduits, mechanical service rooms, chemical storage and dosing facilities, electrical power distribution and large office space. Work also includes selective removals and upgrades to existing process equipment, electrical system, I&C systems, structural work, architectural work, building mechanical systems, fire protection, plumbing and drainage, site work and other miscellaneous work at the Plant Water Pumping Station. This project involves extensive heavy civil components including over 595 piles as well as over 3,000 cubic meters of concrete, placed to date.

Contract Value


Prime Consultant


Project Owner

City of Toronto

Contract Format

Stipulated Price

Completion Date

Ongoing (scheduled for Feb 2023)

Contract Duration

59 months