Upgrades at Toronto’s Ashbridges Bay Wastewater Treatment Plant


Graham has recently been awarded the CDN$236.5 million Effluent Disinfection System at Ashbridges Bay Treatment Plant project by the City of Toronto. Under this contract, Graham will replace the existing chlorine-based effluent disinfection system with a state of the art ultraviolet (UV) disinfection facility. This contract requires three major phases of construction:

  1. Excavation of ash lagoon (hazardous material) and backfill, plant water pumping station upgrades, seawall substation upgrades as well as upgrades to existing seawall gates.
  2. New Disinfection Building including associated UV treatment system, effluent and bypass channels, and site civil work.
  3. New west bypass conduit, east bypass conduit, final UV effluent channels, sample buildings, a new truck weigh scale, lighting, roads and landscaping.

In operations since 1917, the Ashbridges Bay Treatment Plant is one of Canada’s largest and oldest wastewater treatment plants. It is also the largest of four wastewater treatments plants owned and operated by the City of Toronto, serving a population of approximately 1.5 million.

About Graham
Graham is an employee-owned construction solutions partner with revenues exceeding $2.1 billion annually. Graham provides general contracting, design-build, construction management and public-private partnership (P3) services to the buildings, industrial and infrastructure sectors. Headquartered in Calgary, Alberta, Graham has offices throughout North America, including Toronto, and employs 1,200 professionals and office staff, as well as field capacity and self-perform experience of up to 2,000 people. Graham has the resources, capacity and expertise to undertake projects of every scope, scale and complexity.