Basel Tap Water – Naturally Filtered

For water quality in Basel, the origin and filtering of the water are crucial. Basel tap water predominantly comes from the Rhine, with a smaller portion from the Wiese – a river originating from Feldberg. This water undergoes several filtration stages before reaching consumers.

The use of Rhine water is central to the drinking water supply in Basel and the surrounding area, as natural groundwater resources are either insufficient or potentially contaminated. After a coarse pre-cleaning, the raw water is pumped into the groundwater under the Lange Erlen and Hardwald forests. There, it is naturally filtered before being extracted again as clean drinking water.

The aquifers in Lange Erlen (IWB) and Hardwald (Hardwasser AG) supply water for around 220,000 people in Basel-Stadt, Riehen, Bettingen, Binningen, and Allschwil.

To maintain water quality even in the event of incidents in the Rhine, more water is fed into the groundwater than is extracted. Additionally, the quality of the Rhine water is closely monitored before it enters the aquifers.

Top Quality through Continuous Monitoring

Drinking water is one of the most controlled foodstuffs in Switzerland. In Basel, it is checked daily through laboratory analyses. A key quality factor is water hardness: Basel's water, at 19 °fH or 10.6 °dH, is classified as medium-hard. The limit values for soft water are 8.4 °dH (15 °fH).

These values indicate the content of dissolved minerals such as calcium and magnesium. These can be so-called hardness builders and lead to limescale deposits.

✔ Conversion: °fH × 0.56 = °dH

Ensuring Water Quality in Basel at Home Too

Despite the high quality of public water, contamination can occur in domestic installations – for example, by germs in fittings or heavy metals from old pipes.

You can gain certainty about the quality of your tap water through a water test in the laboratory . The sample analysis shows whether your drinking water is free of pollutants.