1 day Ago By CBC
The wastewater leak into the Bow River, which Calgarians were notified about on Saturday, has been fully contained, the city said on Monday. Mayor Jyoti Gondek said crews are working on pumping sewage out of the pipe and finding the cause of the leak, before moving on to repair and replacement work. Alberta Health Services and Alberta Environment and Protected Areas are assisting this work.
Since the leak was discovered on Friday, Gondek noted that sampling tests are now showing water quality near the site has improved, and water flow to the Bonnybrook Wastewater Treatment Plant has returned to normal. "These measures show the leak is fully contained," Gondek said. "This situation is an isolated incident.
I've been advised that this is the first time Calgary has had a wastewater leak from a river crossing using this type of pipe." The city's announcement comes after it received testing results on Friday from the Bow River near the Bonnybrook plant that indicated waste had leaked into the river. After crews identified a leak from a sewage pipe on the river's east bank across from the plant, the leaking pipe was found.
Valves to it were closed and wastewater was diverted to other pipes. When the public was notified on Saturday, Gondek said no water advisories were needed, the risk to the public was low and drinking water was still safe. Doug Morgan, Calgary's general manager of operational services, said he's confident the pipe's leak has been stopped.
Additional wastewater flowed backward through the pipe and into the leak site on Saturday, he noted, but crews anticipated and halted this flow. He added no problems were found in the two pipes water was diverted into. Water quality tests are still being done every four hours.
He added that while there's no way for his team to know exactly how much wastewater leaked into the river, they do know the Bonnybrook plant, which typically receives 365 million litres a day, received seven million litres less on March 19 — a rate that grew each day until a drop of an estimated 52 million litres was recorded on both Thursday and Friday. "Even on what we believed to be the most severe days, the flow at the leak site would have been approximately 1.3 per cent of the total flow in the river," Morgan said, to put the leak in context.
"We also know from modelling and other similar incidents in other cities that the material would have diluted quickly, minimizing effects downstream." Communication flow breakdown After the Bearspaw South Feeder Main break last summer, which led to months of water restrictions, Gondek says the city committed to improving communication to alert senior leadership, as well as the public, on potential problems. On Monday, Gondek said senior city leadership should have been notified earlier about the decline in water flow to the Bonnybrook plant, which was first noticed on March 19, nine days before the leak was discovered and the mayor was alerted.
Gondek argues the delay meant the public wasn't notified early enough, and more people like contractors and private-sector experts couldn't get involved to help find the source of the problem more quickly. "If a red flag had been raised sooner, we may have tested the water sooner and stopped the dangerous flow of waste into the Bow River in a more timely manner," Gondek said. Call for national focus on aging infrastructure Through the city's effort to take a more proactive approach to the health of its pipes, Gondek said the city has begun inspecting aging pipes for potential future problems.
It's all part of a program that will take roughly three years in total. "Calgary was on the front lines of learning what happens when you don't invest properly in monitoring and maintenance," Gondek said. "For that reason, the budget that we passed at the end of November was an infrastructure budget.
We invested in technology, in maintenance as well as proactive planning for redundancies in case of any future emergencies." Gondek advocated for a national focus on aging infrastructure, which has been overlooked in the past in favour of more immediate, short-term investments. She noted it's a common problem in cities across North America, and similar policies should be applied around the country.
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