An investigation is underway after city officials confirmed an “unintentional” wastewater leak into the Bow River in southeast Calgary.
Crews identified the leak around 11 a.m. on Friday on the east bank of the river, near the Ogden Street bridge, about 500 metres away from the Bonnybrook Wastewater treatment plant.
At a press conference on Saturday, city officials said crews first noticed a potential issue on March 19, when monitoring systems showed wastewater levels flowing into the plant were lower than usual and continued to drop as they investigated what was happening.
Water samples from the Bow River were taken on Thursday as crews conducted inspections to find indications of leaks into the river, but couldn’t find any.
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Test results – which came back Friday – showed elevated levels of E. coli near the plant, and upon further investigation, a leak was found. The city said that within three hours of getting the results, it was able to identify the source as one of three pipes that carry untreated wastewater under the Bow River into the plant.
“When we completely shut down the leaking pipe (Friday), we can be grateful that the backup pipe was able to take diverted waste from the situation and the existing third pipe is now acting as backup,” says Calgary mayor Jyoti Gondek.
As a precaution, AHS, Alberta Environment and Protected Areas and communities downstream from the leak were all notified.
“Three wastewater pipes leading to the Bonnybrook plant are designed to support each other in cases like this, ensuring continued service for Calgary,” says Doug Morgan, general manager of operational services.
“Our immediate focus is continuing monitoring and ensuring the release is fully stopped. The city is currently conducting a full assessment to determine the last inspection date for these pipes (as well as ) reviewing long-term maintenance and monitoring strategies to prevent similar issues,” he added.
The city confirmed Calgary’s drinking water hasn’t been impacted and said the risk to the public is low. It is, however recommending that Calgarians and their pets avoid contact with the affected area and that any fish caught be cooked before being eaten.
Wastewater flowing into the plant has since returned to almost normal, and the city plans to give an update on Monday.
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