WC146 JanFeb 2026 - Magazine - Page 17
BONNYBROOK WWTP EXPANSION
$640 million
Location: Calgary, Alberta
Owner: City of Calgary
Project/Construction Manager: Graham Construction
Mechanical Contractor: Balzers Canada Inc.; AECON
Electrical Contractors: The Vector Group,; InCom Electric Corp.
Underground: Standard General Inc.; Whissell Contracting Ltd.; KLS
Earthworks & Environmental: KLS
Engineers: Stantec; Jacobs; AECOM
Other Key Players: WPC Water Solutions; AGAT Labs;
Englobe; EXP; McElhanney; Victaulic (supplier)
Owner Advisor and Construction Insurance Broker: Aon
Legal: Blake, Cassels & Graydon (advisor for the City of Calgary)
Phase 1 saw the addition of two new BNR bioreactors, two new primary
treatment clari昀椀ers, and four new secondary treatment clari昀椀ers to
increase Bonnybrook’s capacity.
point where it’s challenging to do routine maintenance such as
dewatering components when excess capacity is lacking.
“Although we never hit our absolute max capacity, we knew
those days were coming soon if we didn’t keep on building to
stay ahead of the curve,” Jablonski says.
Time was thus of the essence. Initial plans called for the addition of a fourth plant, Plant D, for a 30 per cent increase in
treatment capacity to 1,366,000 people in one fell swoop by
2020. However, it’s been a long haul getting there. A province-wide economic downturn in 2015 cooled population
growth projections, so when the City finally broke ground on
Plant D in 2016 the City had already divided the project into
two separate phases to properly reflect adjusted and somewhat
moderated treatment capacity needs.
Work on Phase 1 lasted through 2021 and saw crews add two
new BNR bioreactors, two new primary treatment clarifiers,
and four new secondary treatment clarifiers to increase Bonnybrook’s capacity for an additional 216,666 people, a figure representing two-thirds of the overall planned capacity increase for
Plant D. Phase 1 activities also included upgrading anaerobic
digesters and the ultraviolet disinfection system to bring it in
line with modern technology capabilities.
Climate change projections were also a major project driver
and thus strongly influenced planning. Calgary made headlines
in 2013 when flooding severely impacted much of the city core,
and Bonnybrook, situated right next to the Bow River, was
pretty much submerged. “The river level was so high it backed
up into our outfall and inundated the treatment systems and
channels,” Jablonski recalls. “The overland flooding also filled
the tunnels with water and inundated the plant’s process and
electrical equipment.” The price tag for the damage to
WAT E R C A N A D A . N E T
WATER C AN ADA • JANUARY/ FEBRUARY 2026
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