Open this photo in gallery: University of Calgary researchers check monitoring equipment as they track traces of COVID-19 in the wastewater system in Calgary on July 14, 2021. Wastewater testing for illicit substances is done weekly at six sites throughout Alberta as part of a pilot-study that ends this fall.Jeff McIntosh/The Canadian Press Wastewater monitoring is a cost-effective and reliable tool to help address the toxic drug crisis killing thousands of Canadians each year, giving a window into the prevalence of drug use in certain areas and whether new cocktails are entering the illicit market, Alberta-based researchers say. Wastewater surveillance...