The study looked at water quality changes in the Bow River in Alberta, Canada from 2004 to 2011. They found that the three wastewater treatment plants in Calgary are the main sources of pollutants affecting the river's water quality. Non-point sources also contribute, with their impact varying along the river. The researchers used a mass balance approach and statistical analyses to analyze the water quality data. They suggest that understanding these sources and processes better will help in managing water quality more effectively.