When Wood’s Flats, now the Village of Montrose, was built out as a retirement spot for Cominco workers back in the 1950s, the latest technology was used to run clean water to the new houses.
With the water main now over 60 years old, the cost to replace the outdated pipes is about $9 million – a price that requires some very careful planning by village council.
Asbestos cement (AC) pipe, also known as transite, was a popular choice of engineers for potable water, sanitary sewer and storm drain pipelines from the 1940s to the 1960s.
The lightweight, corrosive resistant pipeline has a 50-year life span, which means the village has to come up with a plan to replace its aging infrastructure before the water service fails.
“It’s the type of pipe that was used back in the day when the majority of Montrose was built,” explained Kevin Chartres, the village’s chief administrative officer (CAO).
“The estimated life of these pipes as per our asset policy is 50 years,” he said. “So every metre of AC pipe in the village has passed its useful life already.”
Chartres clarified that the newer areas of Montrose are on a different system, but the older parts of town, such as 9th Avenue continue to be serviced water through an AC system.
Under the direction of Montrose council, village staff has been developing a financial plan to replace about 7,000 metres of AC pipe since the system recently underwent an assessment through a non-destructive technology called acoustic testing.
“It’s unrealistic that the village could replace them all now,” said Chartres. “The plan is to help us prioritize which ones need to be done first.”
He said the rate of AC pipe deterioration is dependent on factors such as how acidic soil is in a particular area, and that a previous study completed almost 15 years ago, revealed that areas of pipe have already surpassed life limit.
About 6,100 metres of pipe have been acoustically analyzed – which is the preferred method because it doesn’t require physical removal of any pipe from the ground.
A Canadian company called Echologics used its noninvasive technology to measure the speed of acoustic signals in the village’s system and data collected is then used to calculate the remaining pipe wall thickness.
The CAO provided a cost overview to Montrose council during the Sept. 15 meeting, and outlined projected budget funding for the village to move ahead and complete a capital plan this year.
Council approved $6,000 be allotted to a Capital AC Pipe Replacement Plan in 2014, which will be completed by TRUE Consulting, a Trail-based planning and engineering company.
With that direction, village staff can now apply for a provincial infrastructure grant to help fund the planning phase of the capital replacement project.
“Hopefully the assessment will come back and say a lot of the pipe is still good,” Chartres added. “But we need to work our a plan of how to replace it before it fails. That said, it’s not a $9 million replacement that we will be doing in five, 10 or even 20 years, it will be prioritized as per the capital plan.”
Asbestos cement pipe ceased to be produced in the 1970s after health concerns were raised about the manufacturing process.
Materials used to fabricate AC pipe included Portland cement, up to 12 per cent fibres, water and silica or silica-containing materials that were heat cured in an autoclave.
The presence of asbestos fibres in lieu of reinforcing steel provided adequate strength with lower weight, and made AC pipe a viable option for water and wastewater.
According to Health Canada (HC) website, there is no consistent, convincing evidence that ingested asbestos is hazardous. “There is, therefore, no need to establish a maximum acceptable concentration for asbestos in drinking water,” says HC.