1. Dutch tap water is top quality
Our tap water meets very strict standards. Drinking water companies extract water from purifying sources (dunes, rivers, groundwater) and test it continuously. It contains no added chlorine and only minimal amounts of undesirable substances. RIVM stresses that the quality is among "the best in the world". With such pure quality, an additional filter adds virtually nothing: in practice, it does not completely remove any additional harmful substance from the water.
The Netherlands has stringent drinking water laws, which water companies and inspectorates closely enforce. The Human Environment & Transport Inspectorate (ILT) monitors compliance with the Drinking Water Decree. Thanks to this supervision, you are already safe in the Netherlands: the water meets all standards in 99.9% of measurements. So the risk of pollution is incredibly low.
2. Very small health benefits
The remaining contaminants in our tap water are in such low concentrations that they pose no risk. The amount of undesirable substances in tap water is comparable to the active substance from a paracetamol tablet dissolved in six Olympic-sized swimming pools.
3. Filters actually cause problems
In practice, home filters actually pose risks. Wiebe de Vos explains: "You have to clean the filters and membranes regularly. In home water filters, the water often stands still, allowing bacteria to grow." Leftover contaminants and microorganisms accumulate in the filters. If these detach over time, the 'filtered' water actually contains more harmful substances than ordinary tap water. In short, a filter can be counterproductive.
4. Good minerals disappear
Many filters (especially reverse-osmosis membranes) remove almost all substances from the water. As a result, you also lose useful minerals. Dutch tap water, for instance, naturally contains calcium and magnesium, which are good for your body and pH buffers. If you remove everything at home with a filter, the water does not actually become healthier. Not even if you later add a scoop of table salt.
5. High cost and environmental impact
Home filters are often expensive and consume a lot of water. For example, membrane and osmosis systems produce wastewater: half of the tap water can be lost in purification. You also have to clean or regenerate the filters (as with salt in softeners). This incurs costs and unnecessarily burdens the environment. For the average Dutch person, this is far too expensive for something that has no health benefits.
Filter sellers and other influencers like to use misleading claims to scare consumers. This makes it more likely you'll buy such a filter. In the Netherlands, you are better off trusting the strict controls and modern technologies (such as membrane technology from UT) of drinking water companies. "Their systems are much safer and better controlled than a home filter can ever be," says De Vos.
