· Drinking water
Water hardness rankings refreshed for summer 2026
Municipal drinking-water hardness readings are back on the atlas with updated prairie and Ontario city pages. Hardness is a use metric for soap, scale, and taste.
By OpenStats research desk
Summer refresh is live on the water quality atlas: municipal hardness and related drinking-water parameters are updated for cities with direct municipal report coverage, including prairie standouts such as Calgary and Regina, plus larger Ontario pages such as Toronto and prairie neighbour Winnipeg.
Hardness measures use, scale, and taste
Hardness measures dissolved calcium and magnesium, usually as milligrams per litre of calcium carbonate. Health Canada does not set a maximum acceptable concentration for hardness because those minerals at typical municipal levels are not treated as a health limit. The figure still matters for soap, scale, appliances, and taste, which is why municipalities publish it and why OpenStats surfaces it next to pH and other report fields.
Soft water (roughly 0 to 60 mg/L) lathers easily; very hard water (above 180 mg/L) leaves more scale in kettles and heaters. Prairie groundwater systems often run harder than Great Lakes surface supplies. That pattern shows up again in this month's city pages, but every reading should be read with its data tier: direct municipal reports outrank regional proxies.
How to read the update
Start with a hometown on this hub, then follow the water atlas link for the municipal table. The drinking water hardness guide explains the soft-to-very-hard classes in plain language. For property-level decisions, use your utility's report or a licensed professional. Community averages describe a geography, while a single tap needs a local reading.
YMYL topics on OpenStats stay factual and sourced. Seed or fallback rows stay labeled until a live municipal source covers that place directly; see editorial standards and methodology.