Water hardness in Sion (canton of Valais): 23.9°fH, quality index 7/10. Official Swiss cantonal data.
✓ Compliant with sanitary standardsSion has soft water (23.9°fH). Low limescale risk: descale appliances every 3 to 4 months as a precaution.
Swiss tap water is subject to the federal Food Act (LDA/LEDAl) and the Ordinance on drinking water (OPBD). The sanitary compliance indicator shows whether the latest cantonal analyses found any non-conformities on parameters such as bacteriology, nitrates or heavy metals.
The TH (Total Hardness) measures calcium and magnesium content. Below 15°fH: very soft. From 15 to 25: soft. From 25 to 32: moderately hard. From 32 to 42: hard. Above 42: very hard. Sion's water is moderately hard at 23.9°fH.
Maintenance budget: ~£67/year
For 2 persons, water at 23.9°f deposits around 1.1 kg of limescale per year in your appliances. Estimated cost in descalers, salt and filters.
Calcium: ~38 mg per litre
Your water provides 38 mg of calcium/L, which is 4% of the recommended daily intake.
Filter jug: cartridge every 5 months
At 23.9°f, replace the cartridge every 5 months. An under-sink filter lasts 6 to 12 months.
The tap water hardness in Sion is 23.9°fH, corresponding to moderately hard water. In comparison, the Suisse romande average is 24°fH and the Valais cantonal average is 18°fH.
Yes. The water in Sion is sanitary compliant (Swiss Food Act LDA and Drinking Water Ordinance OPBD). The hardness of 23.9°fH affects taste and appliance maintenance, not safety. Swiss tap water is subject to strict regular monitoring by cantonal authorities.
At 23.9°fH, a water softener is optional in Sion. Regular descaling (every 1 to 3 months depending on appliance) and a pitcher filter are sufficient to limit limescale buildup.
A hardness of 23.9°fH corresponds to approximately 38 mg of calcium per litre, or 4% of the recommended daily intake. This calcium is not dangerous; hard water can even contribute to your daily calcium intake.
Water in Sion is distributed by cantonal utilities in the canton of Valais (EauSud, SINEF, ABV, OIKEN, SIG, Viteos or municipal services depending on the city). Source: OIKEN SA 2024.
Data: official cantonal utilities (EauSud, SINEF, ABV, OIKEN, SIG, Viteos, municipal services) (2024–2026).