From groundwater to tap - Where does Swiss tap water actually come from?

Tap water is supplied to individual households in Switzerland by the surrounding waterworks. For this purpose, the waterworks process so-called raw water from various sources. After treatment, the drinking water is then produced from these sources. Depending on the region, the waterworks in Switzerland obtain approximately 40 % of the raw water for tap water production from groundwater, 40 % from springs and 20 % from surface waters such as lakes and rivers.

The water cycle

The water is in a constant cycle.

Due to the effect of solar radiation, water evaporates from seas, lakes and rivers and rises up into the earth's atmosphere in the form of water vapour. The temperature difference causes the water vapour to condense into water droplets. This forms clouds in the Earth's atmosphere. More and more water droplets accumulate in the clouds due to further condensation of water vapour. As soon as the accumulated water droplets have become too heavy, they empty themselves in the form of rain. This causes the previously evaporated water to fall back to earth into the oceans, lakes and rivers.

A large part of the rain, however, falls to the ground and seeps away. This forms the groundwater, which in turn forms the lakes and rivers. At correspondingly low temperatures, as they prevail in winter, the water droplets in the clouds crystallise into tiny snow crystals. The snow crystals gradually increase in size and weight as more water droplets crystallise. As soon as the snow crystals have become heavy enough, they fall to earth in the form of snow. This is how glaciers are formed, for example.

The water then evaporates again through renewed solar radiation and the water cycle begins again.

From groundwater to drinking water

For raw water extraction, groundwater is pumped to the earth's surface and piped to the waterworks. If the raw water for the subsequent tap water comes from spring, lake or river water, this water is also piped from the corresponding source directly to the waterworks in the region. The waterworks then purify the raw water and process it into tap water for later use. After treatment, the tap water is usually first piped to a water storage tank and from there to the individual households.

The quality of Swiss tap water

Swiss tap water is basically of very high quality and is among the cleanest and purest water in the world. On the one hand, this is due to the fact that about 40 % of the tap water in Switzerland consists of spring water. Spring water has always seeped through several layers of humus, gravel and sand as well as many layers of rock before it emerges at the source. As a result, this water has already been naturally filtered and purified to a very high degree. On the other hand, the Swiss waterworks are obliged by the Foodstuffs Act to regularly check their treated water for possible microorganisms, chemical impurities and other pollutants that are hazardous to health.

Exclude possible contamination

According to reports by SRF, the Luzerner Rundschau, the news portal Bzbasel.ch and according to other reports, however, various impurities and pollutants are also found from time to time in purified tap water in different regions in Switzerland, for whatever reason.

The causes for this can be manifold. In any case, one weak point in the water supply network is the water mains pipes. All the water pipes that run across the country and also to the houses and flats have only a limited lifespan. This is also mentioned in a report on Hausmagazin.ch. Due to this limited lifespan, individual pipes in the water supply network must be regularly repaired or replaced. During these repair works and due to a deteriorating condition of individual pipes over the years, there is basically the possibility that the tap water can become contaminated or that its quality deteriorates. The responsibility for a perfect quality of the tap water has been transferred to the house owners by the legislator. The house owners are thus obliged to ensure that the tenants of the respective house are supplied with high-quality drinking water. For this reason, water analyses, which can also be carried out by the tenants themselves from time to time, are recommended. Furthermore, it is important, for example, for kindergartens, schools and of course also for parents, that a perfect quality of the drinking water is guaranteed here.

With the help of our water analyses and water rapid tests, you always have the possibility to quickly and easily determine your water quality yourself.

With our proven test kits, water quick tests and also with our laboratory analysis, heavy metals, many other risk parameters and possible pollutants can be detected quickly and easily in the tap water in order to be able to counteract this if necessary.

The water is in a constant cycle.
Due to the effect of solar radiation, water evaporates from seas, lakes and rivers and rises up into the earth's atmosphere in the form of water vapour. The temperature difference causes the water vapour to condense into water droplets. This forms clouds in the Earth's atmosphere. More and more water droplets accumulate in the clouds due to further condensation of water vapour. As soon as the accumulated water droplets have become too heavy, they empty themselves in the form of rain. This causes the previously evaporated water to fall back to earth into the oceans, lakes and rivers.
A large part of the rain, however, falls to the ground and seeps away. This forms the groundwater, which in turn forms the lakes and rivers. At correspondingly low temperatures, as they prevail in winter, the water droplets in the clouds crystallise into tiny snow crystals. The snow crystals gradually increase in size and weight as more water droplets crystallise. As soon as the snow crystals have become heavy enough, they fall to earth in the form of snow. This is how glaciers are formed, for example.
The water then evaporates again through renewed solar radiation and the water cycle begins again.