Wildfire season is getting longer in Alberta every year with climate change, scorching land and polluting the air with thick smoke. But, the City of Calgary is studying another, perhaps less obvious, impact of wildfires — drinking water contamination. There haven't been any major fires in the Bow and Elbow river watersheds, upstream of the City of Calgary, for years. But, there are fears a major fire west of the city could wash burned material into the rivers, impacting the drinking water supply for the city's 1.4 million residents.