03/11/2024
Serving over 3.6 million customers, Toronto Water is one of the largest municipal water, wastewater and stormwater utilities in North America. Toronto Water’s Humber Treatment Plant is located at the mouth of the Humber River in Etobicoke, a suburb west of downtown Toronto. This plant is Toronto’s second largest wastewater treatment facility, serving a population of approximately 662,000. As part of Toronto’s large-scale Capital Improvements Program (CIP), the Humber Treatment Plant - South Plant required upgrades to address aging infrastructure and buildings, optimize operational performance, and address community concerns.
Toronto Water was looking for a supplier with global wastewater treatment resources and experience with engineering and construction for tight urban spaces. Black & Veatch was selected to work with the City of Toronto’s Engineering & Construction Services (ECS) division and provide detailed design, program management, and construction management services for the South Plant upgrades. During the design phase, Black & Veatch determined that only one process train (comprising of one aeration tank and four final clarifiers) could be taken out of service at any given time to maintain existing facility operations throughout construction. The team performed multiple constructability reviews to develop a feasible sequencing plan, avoiding operational disruptions and ensuring compliance with effluent discharge requirements set by the Ministry of the Environment, Conservation and Parks (MECP). City of Toronto ECS and Black & Veatch in conjunction with Toronto Water fostered a collaborative owner/contractor relationship through effective communication and regular team-building meetings.
Updates to the Humber Treatment South Plant included aeration tank modernizations, ferrous chloride feed system replacements, a new Return Activated Sludge (RAS) building, final clarifiers enhancements, electrical substation upgrades, and a new effluent pumping station.
Like most CIPs in major cities, the Humber Treatment Plant upgrades came with numerous challenges that the team had to overcome. In Tunnel Gallery T19, an existing pipe that collected effluent from the final clarifiers needed to be removed to make space for a new scum tank. The effluent conduit discharged to an outfall to Lake Ontario; since it was located below lake level, the galleries were in danger of flooding if the pipe was ever breached. To protect the pipe and proactively reduce the risk of flooding, the team cut an opening into the effluent conduit and sent a professional diver to insert a plug and install a plate with a gasket. From the tunnel side, a plate was welded on and the pipe was filled with grout and encased flush to the wall.
With substantial completion achieved in November 2022, the modernized Humber Treatment Plant handles 125 million gallons per day (473 million liters per day) to keep up with Toronto’s rapidly growing population. Construction was strategically sequenced to mitigate any disruptions to facility operations. These upgrades create safer conditions for utility staff, ensure reliability of wastewater treatment processes, and maintain the beautiful City of Toronto landscape.
About Black & Veatch
Black & Veatch is a 100-percent employee-owned global engineering, procurement, consulting and construction company with a more than 100-year track record of innovation in sustainable infrastructure. Since 1915, we have helped our clients improve the lives of people around the world by addressing the resilience and reliability of our most important infrastructure assets. Our revenues in 2022 were US$4.3 billion. Visit www.bv.com and on social media.
