You turn on the tap, fill your glass and drink. Without thinking. Because Dutch tap water is the best in the world, isn't it?
It meets the standards, that's true. But the rivers and groundwater from which it is made are becoming dirtier every year. PFAS, medicine residues, pesticides: drinking water companies have to work harder and harder to remove them. And what happens in the pipes in your own home, no one checks. Time to take a closer look at what comes out of your tap.
What is in your tap water?
Our drinking water comes from groundwater for roughly 60 percent and from surface water, such as the Rhine and the Meuse, for 39 percent. Drinking water companies themselves say that the quality of those sources has been declining for years. They find more and more pesticides, medicine residues and highly concerning substances such as PFAS in them (Omgevingsweb).
PFAS: the substance that never disappears. PFAS are also called 'forever chemicals', because they hardly break down. The tap water meets the legal standard, but the RIVM warns that the Dutch are getting too much PFAS from all sources combined. If you live in the western Netherlands, where more river water is used, the levels in your tap water are structurally higher (Radar). Sewage treatment plants cannot completely remove PFAS. As long as they are produced, they remain in the cycle.
Medicine residues. Every year, an estimated at least 140 tons of medicine residues end up in surface water via sewage treatment in the Netherlands (Rijksoverheid). Painkillers, antibiotics, antidepressants. The concentrations in the tap water are very low, but the amount in the sources is growing due to an aging population and increased medicine use.
Lead from your own pipes. This problem only arises in the home, after the water meter. In an estimated 100,000 to 200,000 homes built before 1960, there are still lead pipes that have never been replaced. Lead particles can enter the water from them, which is especially harmful to babies and young children (NOS). New pipes can also release metals for the first few months (Radar).
When things go wrong. In the Netherlands, it also happens that a water company issues a boil advisory, for example after work or in the event of contamination. Then you may have to boil all your drinking water for weeks.
The tap water is not unsafe. But 'it meets the standard' is different from 'there is nothing in it'. Anyone who wants to decide for themselves what they take in can take an extra step.
How does filtration work?
A water filter removes substances from water in two ways: by holding them on a surface, or by stopping them because they are too large. Most filters for home and on the go combine one or more of these techniques.
Activated carbon. This is carbon that has been processed so that it is full of tiny pores. One gram therefore has a huge inner surface area. Substances in the water stick to that surface; that is called adsorption. Activated carbon is especially good at removing organic substances and improving taste and odor. What it usually does not stop are minerals such as calcium and magnesium, and for microorganisms it usually needs an extra step (Crate Club).
Ion exchange. Here, unwanted particles with a charge, such as lime or certain metals, are exchanged for harmless ions. This is often found in filter jugs and softens the water.
Membranes. A membrane works as an extremely fine sieve. The smaller the pores, the more is stopped. Ultrafiltration, for example, stops bacteria and particles. Reverse osmosis goes the furthest and removes almost everything from the water, including the minerals.
How well a filter works does not only depend on the technology. The amount of filter material, how long the water stays in it and how old the filter is also matter.
Which filter is right for you?
The best choice depends on where you drink and what you want to achieve.
| Type | Where | Technology | Minerals remain? | Suitable for |
|---|---|---|---|---|
| Filter bottle | On the go | Usually activated carbon | Yes | Anyone who wants to drink tap water everywhere and does not want to buy disposable bottles |
| Filter jug | At home, in the refrigerator | Activated carbon + ion exchange | Partially (less lime) | Anyone who wants softer water or better taste at home |
| Tap or sink filter | At home, directly on the pipe | Activated carbon, sometimes with membrane | Usually yes | Households that want to filter all drinking and cooking water |
| Reverse osmosis | At home, under the sink | Fine membrane + pre-filters | No | Anyone who wants to remove almost everything from the water; it costs more and flushes water away |
What to pay attention to
A fresh filter works best. Every filter does its job until it is full. Anyone who regularly replaces a filter knows for sure that the water is always optimally filtered. We therefore recommend a fresh filter every month: small moment, big difference.
Made for tap water. A filter bottle is intended to make your tap water better, at home and on the go. If your water company issues a boil advisory, then simply follow it.
You solve the lead problem at the source. If you live in a house built before 1960, then have the pipes checked. Flush the tap until that time before drinking. A filter can help, but does not replace new pipes.
Minerals are not a problem. Calcium and magnesium in tap water are healthy and give taste. A filter that leaves them in is therefore not a disadvantage.
Finally
The quality of our drinking water sources is declining, PFAS continue to accumulate and what happens in your own pipes, you often do not know. You do not have to be afraid of your tap, but blind trust is also not necessary. A good filter gives you an extra layer of control over what you drink, at home and on the go. Replace it in time and use it for tap water.