CANMORE – There will be no cost to Canmore taxpayers from last year’s boil water advisory and systemwide flushing that left parts of the community without drinking water for more than a week.
Members of EPCOR presented findings to Canmore council Tuesday (April 19) after completing the nine-month investigation to determine the cause of the boil water advisory.
According to the investigation, there isn’t one likely cause, but EPCOR has pointed to an excess of sediment in the lines as the most likely reason.
“The accumulation of sediment in the existing distribution system was most likely the cause of the high turbidity,” said Vicki Campbell, EPCOR’s senior manager of capital, growth and operations. “That’s due to the lack of routine flushing program.”
Campbell couldn’t tell council the total cost to EPCOR without going in camera, but that the company was covering all costs and the capital project for the new waterline is on budget.
The investigation found three factors led to the 10-day boil water advisory that impacted Canmore and nearby residents last summer.
The complexity of the Canmore water system, the lack of a system wide hydraulic analysis and the amount of sediment in the water system were all outlined as the reasons for the advisory.
A staff report to council stated the Town’s topography and water sources are part of the complex system in Canmore that needs multiple water pressure zones managed through pressure reducing valves.
Had there been more hydraulic analysis throughout the system, it could have revealed the issue, though it is not normal practice, according to the report. Finally, the system had a large amount of sediment due to a lack of regular pipe cleaning.
High turbidity is when water becomes cloudy or hazy from a large number of individual particles and caused from a range of reasons such as mud, wood ashes and melting glaciers.
Campbell said a unique issue in Canmore is that water can’t be discharged over land the regular way since there’s not a full storm sewer system. That means flushing needs to be completed more slowly and areas found to flush into that won’t lead to flooding.
“Canmore has some unique issues where the flush water can’t be discharged over land … These sensitive areas in the valley bottom, there’s not a full storm sewer system like in most communities that we could discharge it to,” she said. “There’s a lot more challenges than the easy way of doing things.”
Campbell noted EPCOR is working with a technical expert to find an efficient way to clean the lines and a report is expected to be complete by the end of April. She said areas of concern for sediment are Cougar Creek, Kananaskis Way and Elk Ridge.
The hydraulic analysis modelling is also not a usual practice, Campbell said, but one being undertaken due to the uniqueness of the Canmore system.
Kevin Visser, EPCOR’s senior manager of regional operations, said additional workers came from Edmonton, Chestermere, Kananaskis and Strathmore to help during the boil water advisory.
He said most of the crews worked towards flushing the lines, while others did advanced work to prepare for the next area to be cleared. It was flushed in a safe manner such as avoiding flooding basements and not discharging into a source of water.
“Really high groundwater levels prevent us from putting in a traditional storm system. … There was a lot of coordination going into that,” he said, adding more than 200 hydrants were flushed.
The boiling water advisory from Alberta Health Services began July 29 to Aug. 9, 2021 and was first detected in the Cougar Creek area by residents.
Canmore, Dead Man’s Flats, Harvie Heights and the Canmore Nordic Centre were all part of the initial advisory due to high turbidity being detected.
It was detected when a new water line was being installed as part of the South Bow Loop capital project under the Town’s 2017 utility master plan in the southeast of town. The first phase had 400 metres of piping installed from the Three Sisters Parkway to the Bow River to connect with existing pipe under the river then connect with the wastewater treatment plant.
The second phase was where the water issues were detected and would give the Town a third connection to have the second pumphouse supply water to the Benchlands Reservoir. The project will eventually connect the Three Sisters area to Bow Valley Trail beneath the Bow River to improve the flow of water, address pressure issues and give better water flow for fire crews.
The commissioning of the water pipe is planned for July, but the report highlighted that due to issues last year, it will take “considerable effort” in a revised plan.
Andreas Comeau, the Town’s manager of public works, called the work “an important and valuable project” that will add another secure way to move water to all ends of Canmore. It also adds potable water to the wastewater treatment plant and the waste management plant.
Each of the two phases cost more than $3 million, Comeau said.
Potable water trucks were setup at multiple locations in Canmore and EPCOR staff systematically flushed the water lines, monitored and tested the water supply before declaring it safe.
“I think everyone takes potable water for granted all the time,” Coun. Wade Graham said. “It’s not until you don’t have it that it’s a major concern.”
