The Soft Water in Zurich

The so-called “Züri water” is sourced approximately 70 % from Lake Zurich, about 15 % from springs, and the remaining 15 % from groundwater. Zurich’s water utility thus supplies not only the city itself but also 67 surrounding municipalities with high-quality drinking water.

Many people find Zurich’s water particularly pleasant due to its low hardness.

The water hardness in Zurich is 14–19 °fH (7–10 °dH). The threshold for soft water is 8.4 °dH or 15 °fH – meaning Zurich water ranges from soft to moderately hard.

These values indicate how many calcium and magnesium ions – the so-called alkaline earth metals – are dissolved in the water. The more there are, the harder the water. In everyday life, these minerals form what is known as “limescale.”

Top Quality from the Supplier

The quality of Zurich’s drinking water is excellent. Approximately 5 000 microbiological and chemical analyses are conducted each year. These tests comply with the strictest requirements in Switzerland for food products. The water is considered safe up to the house connection and is carefully treated in modern facilities.

Nitrate Levels: Well Below the Limit

Chemical analyses show an average nitrate concentration of 10 mg/L – the legal maximum is 40 mg/L. Elevated nitrate levels indicate intensive agricultural activity, but Zurich remains largely unaffected.

Züri Water: Affordable and Low-Scale

Compared to bottled mineral water, Zurich tap water is up to 1 000 times cheaper – and more environmentally friendly. Its low limescale content also saves on detergent and extends the lifespan of household appliances. Drinking tap water conserves both resources and your wallet.

Why a Water Analysis Still Makes Sense

Despite strict controls, contaminants can arise in house installations – e.g. from old pipes, heavy metals, or microbes. From the house connection onwards, responsibility lies with the owner. A professional analysis provides clarity.

Further Information:
City of Zurich: Water Supply