Tap Water in Switzerland: Quality and Controls

Tap water is one of the most monitored food products in Switzerland. Nevertheless, it occasionally comes under scrutiny. Recently, the contamination of Swiss groundwater with a concerning pesticide—chlorothalonil—made headlines. However, this was not due to a lack of water monitoring.

The Federal Food Safety and Veterinary Office (FSVO) had just classified the breakdown products of the fungicide as "probably carcinogenic." Therefore, water had not been tested for this substance before. Naturally, similar situations can occur with other water constituents. Generally, however, you can assume that tap water in Switzerland is safe to drink.

What Regulations Exist for the Constituents of Tap Water in Switzerland?

Tap water is a natural product, whose constituents largely depend on the raw water. Therefore, in regions where raw water is sourced for drinking water treatment, special attention is paid to groundwater and water protection.

Legally, the regulations for water quality are governed nationally. However, Switzerland follows the guidelines of the EU.

The Federal Constitution describes the protection of health and consumers under Articles 97 and 118. The Food Act clearly defines the legal requirements for drinking water. Cantonal water suppliers must have a quality assurance system that ensures compliance with the following regulations:

• Ordinance of the FDHA on Drinking Water and Water in Publicly Accessible Baths and Shower Facilities (TBDV)
• Food and Commodities Ordinance (LGV)

Tap Water Minerals: What Should Be Present

Almost everyone knows that tap water contains minerals. They are among the desired water constituents. Regularly drinking tap water provides your body with essential minerals and trace elements. The following natural minerals are found in tap water:

• Calcium
• Magnesium
• Sodium
• Potassium
• Iron
• Manganese
• Chlorite
• Sulfate
• Carbonate

Tap Water Contaminants: What Might Be Present

Depending on the region and season, tap water may contain various trace substances. These include water constituents such as metals, germs, nitrate, pharmaceutical residues, pesticides, or microplastics. At certain concentrations, trace substances can be harmful to your body.

It's normal for tap water to contain contaminants. Even branded water contains trace substances. However, continuous monitoring ensures that the concentration of contaminants remains so low that your health is not at risk, even with lifelong consumption. Therefore, there are strict limit values for tap water that must be adhered to.

Tap Water Limit Values in Switzerland

• Aluminum: 0.2 mg/L
• Ammonium: 0.5 mg/L
• Lead: 0.01 mg/L
• Cadmium: 0.005 mg/L
• Chromium: 0.05 mg/L
• Enterococci (bacteria): 0 mg/L
• Escherichia coli (bacteria): 0 mg/L
• Copper: 2 mg/L
• Nickel: 0.02 mg/L
• Nitrate: 50 mg/L

How Is the Quality of Tap Water Ensured?

Over 2,500 water suppliers provide households in Switzerland with drinking water. Each has an elaborate quality assurance system with modern analytical instruments. Today's measurement methods are so precise that a sugar cube dissolved in Lake Zurich can be detected.

Unlike in the past, many more substances are now detected in water. This also leads to the detection of new—and old—trace substances.

✪ However, this does not mean that the quality of tap water is deteriorating. The ability to detect groundwater contamination at the nanogram level leads to more effective strategies for improving drinking water quality.

Of course, it's not impossible that occasional incidents occur—for example, during floods or algal blooms. But in such cases, the population is usually informed by the water supplier.

If you want to be sure about the quality of your tap water, you can have it analyzed for potential contaminants. Additionally, you have the option to test your drinking water for mineral content. This way, you can drink your local tap water year-round and also help protect the environment.