June 2022 Vol. 77 No. 6


$1 Billion Wastewater Plant Upgrade Leverages Modern Solutions

David Horton | Victaulic 

Across North America, population booms are putting pressure on the capacity limitations of aging municipal wastewater treatment plants. Local municipalities must decide to either build additional facilities or expand existing ones to address growing demand for wastewater services and clean water. 

Large-diameter AGS couplings were used in the project’s buried applications.
Large-diameter AGS couplings were used in the project’s buried applications.

As the largest city in Alberta, Canada, Calgary is home to 1.3 million residents and is considered one of Canada’s fastest-growing municipalities. Originally built in the 1930s, Calgary’s Bonnybrook Wastewater Treatment Plant is one of the largest biological nutrial removal plants in Canada and the largest wastewater treatment plant serving the area. 

Despite efforts over the years to increase treatment capacity through upgrades, Bonnybrook’s existing infrastructure was under-equipped to meet the needs of Calgary’s rapidly expanding population. In 2014, the local municipal government committed to investing more than $1 billion to renovate and expand Bonnybrook’s capacity to approximately 1.4 million citizens by 2024. 

Work on phase 1 of the Plant D expansion, the largest component of the Bonnybrook Expansion Program, began in 2016. Contractor Graham General and mechanical subcontractor Balzer’s Canada Inc. were tasked with upgrading existing solids-handling digesters, as well as installing new primary clarifiers, secondary clarifiers, and secondary treatment bioreactors, and new thermal hydrolysis, effluent filtration, biogas handling and storage facilities. 

As a large wastewater treatment plant, Bonnybrook’s specifications demanded the use of large-diameter valves, up to 48 inches. Additional piping solutions were also prefabricated for ease of installation on systems, including mixed liquids suspended in solid lines and buried lines going to the clarifier ponds. 

Alternative pipe-joining solutions 

Victaulic was engaged by Balzer’s Project Manager Kyle Hucul, to provide a variety of grooved solutions that enabled efficient installation of the piping systems throughout the project. The project scope included replacing the traditional M11 harness system with Advanced Groove System (AGS) couplings on 42-inch to 48-inch pipes. 

Victaulic Series W719 Butterfly Valve and AGS couplings were installed in tight spaces within the valve vault to allow thermal contraction and expansion, reducing footprint.
Victaulic Series W719 Butterfly Valve and AGS couplings were installed in tight spaces within the valve vault to allow thermal contraction and expansion, reducing footprint.

This eliminated flanging of up to 100 bolts throughout a single system and allowed simpler connections. The joint only requires four nuts and bolts on either side to install. 

“I typically like to avoid bolting up because you often encounter time-consuming issues, like misplacement of a few studs or nuts from the thousands of bolts we order. With Victaulic, we were able to eliminate the need to flange. All our team had to do was cut, groove and join. It saved a lot of time,” Hucul said. 

Finding an abundance of skilled labor able to weld or appropriately bolt up flanges is a pressing challenge, as every sector of the construction industry grapples with worker shortages. 

Due to the combination of the easy-to-install grooved designs and prefabrication solutions, Balzer’s Canada Inc. was able to reduce the number of skilled laborers needed for the job, while completing Plant D’s piping installations on a reduced schedule. 

“We simply dropped in the spool pieces and connected them,” Hucul explained. “The ease of installation also allowed my crews to accommodate misalignments because they did not need to rework and reweld any parts to do so. 

“We were able to install hundreds of feet of large-diameter pipes underground in a couple of weeks. The client was very happy.” 

The project also employed Victaulic pipe joining solutions and valves, including vertically installed Series W719 Butterfly Valves on large-diameter pipes, 14-inch Series 365 Plug Valves installed by rings, Victaulic Style 31 AWWA couplings for the sludge lines, and Bermad Series 972 Pressure Reducing Valves, expediting installation and improving safety. 

Dynamic movement 

A detailed stress analysis calculates the expected rate of differential settlement and identifies where settlement will occur when applying traditional buried services solutions, like an M11 harness. 

However, since Victaulic’s AGS coupling is designed for dynamic movement and accommodates both settlement and thermal contraction and expansion, contractors working on the Bonnybrook Expansion Program didn’t have to worry about calculating settlement risk or needing to re-excavate and backfill due to relaxed bolts. 

This solution allows more couplings to be placed close together as part of its dynamic design, requiring less space for trenching and, therefore, accelerating schedules and reducing worker safety risk. 

Large-diameter AGS couplings were used in the project’s buried applications.
Large-diameter AGS couplings were used in the project’s buried applications.

Graham General and Balzer’s Canada Inc. impressed project stakeholders with their ease of installation and ability to simplify requirements for construction. The contractors significantly reduced the concrete footprint of the valve vault – and, in turn, the concrete schedule – by introducing Victaulic’s Series W719 Butterfly Valve to the project. 

The grooved solutions used for wall penetration allowed for installation close to a wall, enabling construction in an area where it was not possible to install traditional flange valves. 

“The end wall leading into the bioreactor had a lot of pipe penetrations that were cast in place. If we had had to use flanges for this portion, it would have required us to cut the formwork apart to seal the pipes before completing the concrete pour,” Hucul said. 

Welding and flanging alternative solutions offer operators significant time- and cost-saving benefits. When the lines require maintenance, the couplings can be disassembled much quicker and easier than if they were flanged or welded. 

“They can simply pull off the pipe spools, flush them out and rebuild them,” Hucul explained. 

Collaborative partnership 

By working together on the massive, billion-dollar Bonnybrook expansion, Graham General, Balzer’s Canada Inc. and Victaulic were able to incorporate modern and cost-effective pipe-joining solutions across the entire system that improved safety and reduced risk while allowing crews to stay on top of scheduled completion dates despite obstacles. 

After five years of demanding work, contractors completed the first phase of the Bonnybrook Plant D expansion in 2021, providing Calgary’s residents with high-quality wastewater treatment service and the infrastructure to accommodate future growth. UC 


Victaulic, (610) 559-3300, victaulic.com 

Graham, (403)570-5000, grahambuilds.com 

Balzer’s Canada Inc., (306) 781-2400, balzerscanada.com 

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