Calgary officials are monitoring the city's water supply following a sewer pipe leak in a municipality upstream on the Bow River, but the city says its tap water remains safe to drink.
Alberta issued a biological hazard advisory late Saturday, stating a main sewer line break within the Town of Cochrane was causing an overland sewage discharge into the Bow at a bridge along Highway 22.
The alert, which has since been cancelled, said Cochrane's drinking water was not affected and remained safe, but people should avoid the area to allow crews to respond to the incident.
Calgary issued a news release on Sunday morning saying it has seen no change in water quality at the Bearspaw Water Treatment Plant, but as a precaution, it has asked people to stay out of the Bow River for the rest of the day.
"We are conducting extra water quality sampling on the Bow and will provide updates as they are available," the news release read.
A Sunday post on the town of Cochrane website said its water remains safe for drinking but restrictions on water use, including outdoors, are in effect.
The town said wastewater was no longer entering the river, but corrected that several hours later to say the discharge had only been "significantly reduced."
"The top priority remains ensuring the continued provision of safe drinking water and implementing all necessary measures to stop the flow," the town's most recent statement on Sunday afternoon said.
"This is a complex and quickly evolving situation and we appreciate your cooperation as we continue to respond."
An earlier statement by the Town of Cochrane said it was told on Saturday at 6 p.m. that a contractor completing work on behalf of the town had "impacted" its wastewater and water pipelines as they were setting up for drilling operations.
The town said an onsite incident response is continuing with work to mitigate the problem.
Ryan Fournier, the press secretary for Alberta's environment minister, said officials with the department are responding and are working with Calgary and Cochrane to ensure drinking water remains safe.
Fournier said any other questions about the sewage release should be directed to the municipalities.
Mark Crowdis, the City of Calgary's manager of water quality and regulatory assurance, said the city's water remains safe because of the treatment is receives at the Bearspaw facility.
"It has the technology and ability to treat this type of contaminent in the water," he said.
Crowdis said additional samples were being taken upstream from the treatment plant's intake, as well as throughout the city's distribution system.
He said officials were hoping to confirm by the end of Sunday that the Bow River was safe for recreational users.
This report by The Canadian Press was first published Oct. 22, 2023.
— By Rob Drinkwater in Edmonton
The Canadian Press
