Canmore’s Wastewater Odour Fix Delayed as Costs Climb to $7.2M

A long-promised fix for Canmore’s persistent wastewater smell will miss its original summer 2026 target, meaning residents frustrated by years of sewage odours will likely endure another season of unpleasant smells despite millions already spent trying to solve the issue.

Town administration told council on May 19 that the permanent odour-control system at the Canmore Wastewater Treatment Plant is now expected to be completed in late fall 2026, months later than originally anticipated. The latest cost estimate has also climbed to roughly $7.2 million.

The project centres on enclosing the plant’s open-air sludge holding tanks, known as digesters, which administration says remain the primary source of lingering odour complaints affecting nearby neighbourhoods, particularly in South Canmore.

Back in October 2025, council approved an additional $5 million outside the normal budget process in hopes the system could be operational before the summer of 2026. At the time, officials said the accelerated timeline would allow the town to avoid “another odour season.”

Instead, residents are now being told the town is preparing temporary mitigation measures while the permanent system continues through redesign, procurement and construction.

“We had a little bit of a blip with the province on the regulatory piece,” the Town’s manager of Public Works Andreas Comeau told council during Tuesday’s update.

According to administration, Alberta Environment intervened shortly after council approved the accelerated project last fall, questioning whether enclosing the digester tanks constituted a “process change” requiring amendments to the plant’s provincial operating approval.

“We got a phone call from the province saying what are you guys doing?” Comeau said.

Town officials said they spent months responding to provincial questions while trying to determine whether the project would trigger a formal public notification and approval process that could have delayed the project even further.

“It wasn’t until the second week of February that we finally got confirmation that we were allowed to proceed without an amendment,” Comeau said.

The delay came as engineers and contractors were also substantially redesigning the project itself.

Early concepts presented to council last fall envisioned adding a third enclosed tank roughly the same size as the plant’s two existing digesters. But further engineering analysis led the project team toward a smaller enclosed tank paired with revised piping systems, new operational infrastructure and changes intended to better integrate with the town’s planned long-term wastewater treatment plant expansion.

“There was a lot of things to think about,” Comeau told council.

Administration said the redesign also improved safety for workers and reduced future construction conflicts that could have complicated the larger wastewater plant expansion currently planned for 2031.

The more detailed design work, however, also pushed the project budget higher.

“The project’s going to sit at about $7.2 million with a new overage of $1.65 million beyond what we had anticipated,” Comeau said.

Town administration said the additional costs will be covered internally using savings from other wastewater and underground utility projects rather than through additional borrowing or tax increases.

Council first made wastewater odours a formal priority in 2022 after years of complaints from residents living near the facility.

A consultant’s odour study identified multiple sources within the plant and recommended a phased approach to mitigation rather than attempting a single sweeping fix.

Phase 1, completed in early 2024, installed a chemical injection system to reduce hydrogen sulphide levels entering the plant. While the upgrade successfully lowered hydrogen sulphide concentrations, administration acknowledged it “clearly didn’t hit the mark regarding odours.”

Phase 2, completed in 2025, added a photoionization unit and carbon air scrubber at the plant’s dewatering facility. Although officials said those upgrades significantly improved air quality inside the facility itself, odour complaints from the community continued.

That left the digesters, two large open-air sludge holding tanks, as the remaining major source.

The town’s website still encourages residents to “log an observation” whenever odours are noticed to help staff track patterns and operational issues.

As the permanent solution continues under construction, administration says several temporary mitigation measures are being prepared for this summer.

Fence-line odour sensors are already installed and being monitored by EPCOR, which operates the wastewater facility on behalf of the town.

A second hydrogen peroxide injection point is also expected to be operational by the end of May to help treat sludge before it enters the digester tanks.

If odours worsen, operators may also begin recirculating sludge to prevent it from becoming septic and producing stronger smells.

“We can be fairly adaptive,” Comeau said.

The town is also investigating floating plastic covers that could temporarily sit on top of the sludge tanks to trap odours, although officials warned those systems currently appear to involve long lead times and overseas suppliers.

Mayor Sean Krausert acknowledged the delay would likely disappoint many residents.

“Coming from a place where we hoped it would be done prior to the summer months to where it is now is disappointing,” Krausert said.

Still, he noted the project remains substantially faster than a typical infrastructure delivery timeline.

Under a conventional design-bid-build approach, administration estimated the project could have taken more than two years to complete. Instead, the town opted to simultaneously advance engineering design, contractor involvement and equipment procurement in an attempt to compress timelines.

In the meantime, officials are continuing to encourage residents to report odours when they occur so operators can respond more quickly.

“We are encouraging people to continue to report,” Comeau said.