The preliminary findings from the Bearspaw South Feeder Main pipe investigation will be shared on Nov. 26 at the City of Calgary council meeting.
The purpose of the pipe investigation, overseen by Associated Engineering and Pure Technologies, is to understand the factors that led to the deterioration of the feeder main and its failure on June 5, 2024, according to Calgary’s website.
Some preliminary findings already released indicate that several different factors may have contributed to the feeder main failure, including microcracking of the protective mortar outer layer of the pipe; high chloride levels in soil at various locations; and wires which snapped due to corrosion and hydrogen embrittlement.
The report indicated that there was not one specific factor that led to the failure of the feeder main in June.
Since reparations were made throughout the summer and into November, City officials stated the pipe responded well and is stabilized.
“Through our acoustic monitoring, we have recorded only two wire snaps on the feeder main between October and November,” said Michael Thompson, general manager of infrastructure services. “Throughout July and August, there were 23 wire snaps.”
The final pipe investigation report will be presented at Calgary’s Infrastructure and Planning Committee on Dec. 11.
Long term rehabilitation options of the feeder main are currently being considered, while an enhanced emergency response plan is being developed, equipping the feeder main with Acoustic Fibre Optic (AFO) monitoring and maintaining a critical parts inventory.
The feeder main is a vital piece of Calgary’s infrastructure and supplies water to the City of Airdrie as well as other surrounding communities.