Tap Water: Quality and Safety

Tap water is one of the most closely monitored food products in Switzerland. However, it frequently comes under criticism. Not long ago, the contamination of Swiss groundwater with a concerning pesticide – chlorothalonil – made headlines. This issue, however, was not due to insufficient water monitoring.

The Federal Office for Food Safety and Veterinary Affairs (FSVO) had only recently classified the breakdown products of this fungicide as «probably carcinogenic.» As a result, water had not previously been tested for this substance. Naturally, similar situations could occur with other water ingredients. Generally, however, you can safely drink tap water in Switzerland without concern.

What regulations exist for the ingredients in tap water in Switzerland?

Tap water is a natural product, and its ingredients largely depend on the raw water source. For this reason, regions supplying raw water for drinking water treatment focus heavily on groundwater and water protection. Legally, the regulations on water quality are nationally standardized. However, Switzerland aligns itself with EU guidelines.

Articles 97 and 118 of the Federal Constitution describe the protection of health and consumers. The Foodstuffs Act clearly defines the legal requirements for drinking water. Cantonal water suppliers must have a quality assurance system in place to ensure compliance with the following regulations:

• Ordinance of the FDHA on Drinking Water and Water in Public Baths and Shower Facilities (TBDV)
• Foodstuffs and Utility Articles Ordinance (LGV)

Minerals in Tap Water: What Should Be Present

Almost everyone knows that tap water contains minerals. These are among the desired water ingredients. By regularly drinking tap water, you provide 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

Contaminants in Tap Water: What Might Be Present

Depending on the region and season, tap water may contain various trace substances, such as metals, microbes, nitrates, pharmaceutical residues, pesticides, or microplastics. Beyond a certain concentration, these substances can be harmful to your body. It is normal for tap water to contain some contaminants. Even branded water contains trace substances. Regular monitoring ensures that contaminant concentrations remain low enough to avoid health risks even with lifelong consumption. Therefore, strict limits are enforced for tap water.

Tap Water Quality Standards 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
• E. coli (bacteria): 0 mg/L
• Copper: 2 mg/L
• Nickel: 0.02 mg/L
• Nitrate: 50 mg/L

How Is Tap Water Quality Ensured?

More than 2,500 water suppliers provide Swiss households with drinking water. Each has a sophisticated quality assurance system with modern analysis tools. Current measurement methods are so precise that even a single sugar cube dissolved in Lake Zurich could be detected. Compared to the past, many more substances are identified in water, including new and old trace substances.

✪ Despite this, tap water quality has not worsened. The ability to detect groundwater contamination at nanogram levels allows for more effective strategies to improve drinking water quality. Naturally, isolated incidents such as flooding or algae blooms may occasionally occur, but water suppliers usually inform the public in such cases.

If you want to be absolutely certain about your tap water's quality, you can test it for potential contaminants. Additionally, you can have your drinking water tested for its mineral content. This allows you to drink your local tap water year-round, which also benefits the environment.