Review finds no evidence of 'unprofessional conduct' in Calgary water main break

Amir Said · CBC News

· Posted: May 28, 2025 8:13 PM EDT | Last Updated: May 29

As the one-year day of past June's catastrophic h2o main interruption approaches, an autarkic reappraisal of the incidental suggests that determination was nary wrongdoing by the City of Calgary's engineering oregon geoscience services.

The findings of a caller study by the Association of Professional Engineers and Geoscientists of Alberta (APEGA) suggest that the pre-stressed factual cylinder tube (PCCP) nonaccomplishment experienced by the Bearspaw southbound feeder main is accordant with incidents crossed North America.

"PCCP manufacturing standards were relaxed from the precocious 1960s to the aboriginal 1970s by the American Water Works Association, resulting successful a precocious complaint of premature failures, and standards person since been strengthened," reads a merchandise by APEGA.

WATCH | Pipe worldly to blasted for rupture:

The study recovered "no indications of unskilled signifier oregon unprofessional conduct."

Had specified grounds been found, APEGA would person launched a ceremonial investigation.

Calgary Mayor Jyoti Gondek told CBC News that she's pleased with the findings of the autarkic review.

"I deliberation that's the benignant of reassurance that Calgarians are seeking, that this incidental was managed successful a nonrecreational manner," she said.

The Bearspaw southbound feeder main, Calgary's largest h2o feeder main and the tube that transfers the bulk of the city's treated water, ruptured connected June 5, 2024, flooding a thoroughfare with cleanable water.

Calgarians were asked to severely bounds their h2o usage arsenic repairs got underway.

The metropolis recovered galore sections of tube needed repairs, extending h2o restrictions into precocious September. At the time, Calgarians were prohibited from watering their gardens oregon lawns and were asked to keep limiting their indoor h2o use.

Since then, the h2o main has undergone important repairs, portion the incidental prompted the City of Calgary to adhd h2o organisation infrastructure nonaccomplishment to its database of high-risk exigency scenarios.

The autarkic report's findings are accordant with the results of a reappraisal commissioned by the city in 2024.

Last year's forensic investigation, led by Associated Engineering, cited microcracking on the protective mortar outer furniture of the pipe, precocious chloride levels successful the ungraded astatine assorted locations, and snapped wires pursuing corrosion and hydrogen embrittlement arsenic factors that contributed to the nonaccomplishment of the feeder main, though nary singular origin could beryllium identified arsenic the superior origin of the rupture.

Rupture was 'hard to predict'

Kerry Black, a civilian engineering prof astatine the University of Calgary, said it's important for radical to recognize that the factors down the rupture "are hard to predict," adjacent by experts.

"They truly did person a robust attraction and prevention program successful spot astatine the clip of the rupture," she said. "Certainly we've seen different municipalities looking to the City of Calgary arsenic a model, arsenic an illustration of however you tin bash monitoring and prevention well, but that adjacent erstwhile you do, things tin spell wrong."

The metropolis is liable for 16,000 kilometres of waste, tempest and drinking h2o pipes, according to its ain figures.

"There's a world that monitoring and maintaining each of those kilometres of pipes is difficult," said Black. 

While she believes Calgary has "a bully program successful place," she said the metropolis could bash a amended occupation of communicating its h2o infrastructure work, and the costs associated with that, to Calgarians.

"I cognize it's thing that cipher truly wants to perceive about, but there's a reality: infrastructure costs money," she said. 

"For me, [it's] that semipermanent readying of however are we getting mundane Calgarians to recognize however costly it is to supply the infrastructure that we each trust connected truthful much, and are we consenting to assistance shepherd a way guardant to acknowledging that?"

Gondek said that she and the city's infrastructure services wide manager Michael Thompson volition contiguous "a elaborate summary" adjacent week, highlighting what's been done by the metropolis since past year's incident.