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Bonnybrook Wastewater Treatment Plant Expansion Program

Expanding the world’s largest cold-weather BNR plant

  • 135M


  • $500M

    Construction Value

  • Calgary, Alberta

    Calgary, Alberta

Increasing Calgary's wastewater treatment capabilities

The Bonnybrook Wastewater Treatment Plant is one of the largest biological nutrient removal (BNR) plants in Canada and the largest cold-weather BNR plant in the world. Influent temperatures reach a minimum of 10 C with air temperatures as low as -40 C in the winter.

Population growth and increasingly stringent treatment standards have been the primary drivers for numerous plant expansions since it was constructed in 1932. Currently, the plant provides treatment up to an average capacity of 396 ML/d and peak capacity of 1,069 ML/d to serve 946,000 Equivalent Population (EP), but it is nearing its installed capacity.

Upgrade projects for Secondary Plants B and C are under development as interim measures to provide additional capacity. Parallel to these upgrades, the design of a full treatment plant expansion (Plant D) is currently underway to increase the installed capacity by 325,000 EP (135 ML/d). Peak flow capacity will be increased to 1,390 ML/d.

The project includes upgrades to primary influent conveyance, primary treatment, primary effluent conveyance, BNR process, secondary clarification, effluent filtration, UV disinfection, plant outfall, chemical and process utility systems, secondary sludge thickening, secondary sludge dewatering, thermal hydrolysis of dewatered waste activated sludge, sludge digestion, and biogas management.

At a Glance

The Alberta Floods
Protecting the Bow by rebuilding Bonnybrook
Meet Our Team

Ryan Roberts, Senior Vice President, Water Project Delivery

I believe project success is achieved through open, honest communication and a clear understanding of client expectations and deliverables.
Ryan Roberts Senior Vice President, Water Project Delivery Read More

Francis Rozsa, Principal, Water

Water is our most valuable resource, and we must strive to find better ways to protect it.

Joe Uglevich, Vice President, US Discipline Leader, Water

My experience has proven that successful teams include technical staff, clients, and stakeholders working together towards a common goal.
Joe Uglevich Vice President, US Discipline Leader, Water Read More
  • Ryan Roberts

    Senior Vice President, Water Project Delivery

  • Francis Rozsa

    Principal, Water

  • Joe Uglevich

    Vice President, US Discipline Leader, Water

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