Prairie provinces (mainly Saskatchewan and Manitoba) contain high quantities of calcium and magnesium, often as dolomite, which are readily soluble in the groundwater that contains high concentrations of trapped carbon dioxide from the last glaciation. In these parts of Canada, the total hardness in ppm of calcium carbonate equivalent frequently exceeds 200 ppm, if groundwater is the only source of potable water. The west coast, by contrast, has unusually soft water, derived mainly from mountain lakes fed by glaciers and snowmelt.
Some typical values are:
* Montreal 116 ppm
* Calgary 165 ppm
* Regina 496 ppm
* Saskatoon 160–180 ppm
* Winnipeg 77 ppm
* Toronto 121 ppm
* Vancouver < 3 ppm
* Charlottetown, PEI 140&ndash;150 ppm
* Waterloo Region 400 ppm
* Guelph 460 ppm
* Saint John (West) 160–200 ppm
* Ottawa 30 ppm