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CALGARY — The City of Calgary has announced the selection of Siegfried Kiefer as chair of the independent review panel for the Bearspaw South feeder main break.

The massive feeder main break occurred in June, leading to months of water restrictions and other onerous measures.

News of this appointment followed the Dec. 11 release of the final results of a pipe investigation, which was overseen by Associated Engineering and Pure Technologies, and was conducted to understand the factors that led to the deterioration of the feeder main and its failure.

The findings state there was not one single factor that led to its demise, but rather a few variables.

These include:

• Some pipes showed visible mortar cracking and delamination upon excavation, while other pipes had intact mortar.
• Soil testing along the feeder main showed significantly aggressive soils in certain areas, predominantly due to high chloride concentrations.
• Laboratory testing confirmed some distressed pipes did have chlorides penetrate the mortar, while other pipes showed no evidence of chloride penetration.
• Severe pitting and corrosion of the prestress wires was present, as well as significant quantities of brittle wire failure. The prestress wires were prone to splitting.
• Evidence of hydrogen embrittlement and stress corrosion cracking of the prestress wires was found. Both in this case appear to be due to chloride penetration of the mortar and/or microcracking.

It was also found the original design of the pipe was consistent with the proper guidelines of the time and operations of the pipeline were well within the design parameters of the pipe, a release reads.

The Bearspaw South feeder main is the largest in Calgary’s network and distributes a significant portion of the city’s treated water supply.  Since the pipe failed, 29 pipe segment repairs have taken place to support the stabilization of feeder main.

When it comes to the independent review panel, an advisory group comprised of three community Leaders, Dawn Farrell, Wayne Stensby and Dr. Edward McCauley, were tasked with searching for a qualified chair,

“Kiefer has over 40 years of managing and operating critical infrastructure and will lead the panel in examining what happened, why it happened and what changes are needed to prevent this type of incident from re-occurring,” the release continues.

He will work closely with the advisory group to select an expert panel of senior industry leaders, establish terms of reference and finalize the details of the mandate.

It is expected that the review will take 12 months to be completed.

The panel will be responsible for sharing information and the results of the review. Once those details are confirmed, further updates on the panel members, the terms of reference and the mandate will be shared with Calgarians.

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