An unpleasant odour drifting across much of east Calgary prompted a spike in emergency calls Wednesday, as residents from neighbourhoods stretching from the far north to the deep southeast wondered what was causing the smell. Fire crews were kept busy responding to reports people believed were gas leaks, with some calls coming from schools in northeast Calgary as the powerful stench blanketed parts of the area. Ideas about what the smell might be ranged from natural gas or propane to sewage or even durian fruit. Officials say the odour is believed to be linked to stormwater runoff ponds at Calgary International Airport that collect de-icing compounds, including organic chemicals like glycol. “The compounds they use to de ice when that runoff is collected into retention ponds around the airport, and what it is is when it’s underneath the ice in the winter, most people don’t really notice it.” said Alex Kwan, public information officer with the Calgary Fire Department. “But as soon as we get the warmer conditions in the spring, then it basically smells like a like a rotting type of smell,” he added. The smell was reported across a wide stretch of the city’s east side, often arriving in waves depending on wind conditions. In a written statement to CTV , Calgary Airports said, “Calgary Airports recognizes the odours around the airport are concerning to our neighbours. As ice and snow melt on stormwater ponds and wetlands, naturally decomposing organic material can release odours into the air. The smell poses no risk to public health, and both short- and long-term solutions are actively being implemented.” The airport authority added, “We conduct regular air and water sampling in partnership with The Calgary Fire Department and the City of Calgary, which have consistently shown that air quality remains well within safe limits and the compounds present are not harmful to people, wildlife or fish.” It said mitigation work is ongoing, noting, “While we continue to work towards long-term solutions to be completed in 2027, Calgary Airports’ Environment team is taking active steps each spring to reduce odour impacts. These measures include water treatment, aeration, stormline cleaning, and pond dredging.” Fire officials say while the pond odours are not considered toxic, residents should not assume every unusual smell is harmless. “We’ll always send a crew to investigate regardless, because we don’t want any of those to be missed,” said Kwan, “so we’ll always investigate any one of these kind of complaints.” Officials added the increase in odour complaints can strain resources, even as crews continue to respond to each call to ensure there is no real hazard.
