Worst tap water in the Netherlands?

Reading time: ~12 minutes

What does bad tap water actually mean?

Anyone searching for the worst tap water in the Netherlands is actually looking for two different things: is my water unsafe, and is my water worse than someone else's? The answer to the first question is no. The answer to the second is: in some respects, yes, and those respects can be measured.

At PureFilter, we find that customers rarely call because they think their water is unsafe. They call because they have a limescale ring on their tap, because they read something about PFAS in the newspaper, or because the water at their parents' house tastes different from their own. Those are exactly the three points where the Netherlands does differ: hardness, source, and the substances that make purification work hardest.

Where in the Netherlands is water quality worst?

This is almost always where things go wrong, and the confusion is understandable. The Netherlands genuinely ranks at the bottom in Europe on water quality. But that ranking concerns surface water: ditches, streams, rivers and lakes. NPO Radio 1 reported, based on RIVM research, that the Netherlands is one of the worst EU member states on water quality, partly due to pollution from chemical substances, medicine residues and pesticides.

That is not the same as your tap. Between the ditch and your glass sit ten drinking water companies with purification that, according to the Drinkwaterplatform (Dutch drinking water industry platform), must meet hundreds of requirements, far more than bottled water. Poor source water in the Netherlands therefore does not produce poor tap water. It produces more expensive and more complicated purification, and that is the real problem the sector is warning about.

The real difference: the source of your drinking water

If there is one factor that explains the regional differences, it is the source. According to the RIVM, sixty percent of Dutch drinking water comes from groundwater. In the west of the country, groundwater is too salty, so surface water from the Rhine, the Meuse and the IJsselmeer is used there instead, partly pre-purified through infiltration in the dunes.

Groundwater is rainwater that has sometimes taken centuries to reach its place, filtered through layers of clay and sand and without oxygen, so without bacteria and viruses. River water is young, exposed to everything discharged further upstream, and therefore needs much more intensive purification. If you want to know where your water comes from, that is shown on the map Bron van het drinkwater (Source of drinking water) from Atlas Leefomgeving.

That distinction between source and technique is exactly why it pays to know which filter type suits the water in your region. A filter that tackles limescale does not solve a PFAS problem, and vice versa.

PFAS: where the biggest regional difference lies

PFAS is where the regional difference can be most sharply substantiated, and the figures come from the RIVM itself. By law, twenty different PFAS combined may total 100 nanograms per litre in drinking water, and the RIVM confirms that Dutch drinking water complies. Based on new knowledge about effects on the immune system, the RIVM now recommends a much stricter guideline value: 4.4 nanograms per litre, expressed in PFOA equivalents.

Measured against that stricter standard, a pattern does emerge. The RIVM report PFAS in Nederlands drinkwater (PFAS in Dutch drinking water) states that in more than half of measurements in drinking water made from river water, the concentration exceeds the WHO reference point, versus one in ten measurements in drinking water from groundwater. The highest concentrations are found in the western Netherlands, where drinking water is mainly made from river water.

Two things are worth noting straight away. First, the amount of PFAS from drinking water alone stays on average below the health-based limit; through food, the Dutch take in roughly three times as much, according to the RIVM. Second, the level is not falling quickly, since PFAS barely break down. Anyone who wants to see where PFAS has been measured in the Netherlands can find the measured locations listed there, and the overview of everywhere PFAS turns up explains why the route via food is usually bigger than the one via your tap.

If you live in the west and want to bring that route down to zero, the question is which technique can do that. We explain this on our page about the water filter against PFAS.

Nitrate on sandy and loess soils

The second regional dividing line runs not between east and west but between sand and clay. According to Vewin (Dutch association of drinking water companies), it is mainly the leaching water from farms on sandy and loess soils that contains too much nitrate. Groundwater with more than 50 milligrams of nitrate per litre is less suitable for making drinking water, and in about 20 percent of groundwater abstractions, nitrate, nickel and sulphate are already, or may in future become, a problem substance.

There are even 34 designated vulnerable groundwater protection areas where the nitrate concentration in shallow groundwater must fall permanently below that standard. Again, this concerns the source, not your tap: the tap water coming from those areas meets the standard because the company purifies it further or blends sources. What it means is that purification there costs more effort. How nitrate works, and why infants in particular are mentioned, is covered in our article on filtering nitrate from tap water.

Hardness: the difference you notice

Hardness is the only difference you can see without a laboratory, and it is the difference most people mean by bad water. Evides (Dutch drinking water company) explains that hardness is expressed in German degrees of hardness and can vary considerably by production company depending on soil composition, groundwater flow and agriculture. The dunes are naturally rich in lime, so water there is harder; water from the Meuse is softer, partly because it is already softened in the storage reservoirs.

Hard water is not unhealthy. It leaves limescale on your tap, in your kettle and in your coffee machine, and it makes tea and coffee taste flatter. If you want the value for your own town, it is listed per municipality in our overview of water hardness per municipality. For the background on how hard Dutch water actually is, we have covered hard water in the Netherlands separately.

Chlorine: why Dutch tap water tastes different

This is the point where the Netherlands actually differs favourably on an international level. Because bacteria and viruses are already made harmless during purification using UV light or ozone, and because the pipe network barely leaks, adding chlorine is not necessary. According to the Drinkwaterplatform, only PWN (Dutch drinking water company) and Evides add a minimal amount of chlorine dioxide as a precaution, in a dose that is not measurable at the tap.

If your water smells of chlorine on holiday in Spain or France, that is not imagination but policy. And it is not just a matter of taste: at high concentrations, chlorine can undergo reactions that produce harmful by-products. What chlorine does in water, and why a filter changes that, is covered in filtering chlorine from tap water.

Ranking: how the regions compare

There is no official ranking from best to worst tap water, nor can there be one: all ten drinking water companies supply water that meets the same statutory requirements. What can be done is to place the regions side by side on the three points that differ per area. That produces this picture.

The conclusion from that table is not that there is a loser. It is that the question is being framed wrongly. The western Netherlands has the biggest PFAS challenge and the south the biggest nitrate challenge, while on hardness the dividing line runs differently again. Anyone living in the west therefore has a different reason to filter than someone living in Brabant, which explains why the best water filter for one person is something different than for another.

What you can do yourself if you want certainty

A filter is not a necessity in the Netherlands. The RIVM and the Voedingscentrum (Dutch Nutrition Centre) simply advise continuing to drink tap water, and we endorse that advice. What a filter does do is take responsibility for the last few metres: the part of the route your drinking water company no longer controls, such as the pipes inside your own home, and the substances putting pressure on the source that you would rather not have in your glass at all.

The PureFilter Mineral+ is an under-sink filter with five filtration stages that removes more than 100 contaminants, including PFAS, microplastics, heavy metals such as lead and copper, fluoride, nitrates, medicine residues and chlorine. It is NSF-certified to 42, 53, 61 and 372. The final stage is what sets it apart: via Swedish Mineral Rock™, calcium, magnesium and potassium go back in. Purify first, then mineralise, in that order.

The filter costs €149.00 including the first filter cartridge. A replacement filter costs €65.00 and lasts around twelve months for 1 to 3 people; around six months for 4 to 6 people. The duo with two cartridges costs €115.00. Converted, that is less than one cent per litre, compared with €0.40 to €1.00 for a litre of bottled water. If you would rather not think about it, the Filterplan automatically ships cartridges on time for €48.00 or €86.00 per delivery.

You install it yourself in 5 to 10 minutes on the cold water pipe under your sink. You do not need a plumber; for the installation you use a single pair of water pump pliers, and later you replace the cartridge with the supplied key. A 3/8 connector is included as standard. If you first want to see what fits under a sink, take a look at what water filters we sell.

Comparison: PureFilter next to the alternatives

When comparing, pay attention to the minerals column. A technique that removes everything also removes calcium, magnesium and potassium, which lowers the pH value of tap water. That is exactly the difference between stripping everything out and purifying selectively, and it is why we placed mineralisation as the final step for our under-sink filter.

Looking up the quality of your own tap water

You do not have to guess. In three steps, you know exactly what comes out of your tap.

• Step 1: look up your supplier via the map from Vewin. The Netherlands has ten drinking water companies, and your postcode determines which one serves you.
• Step 2: check the source on the map Bron van het drinkwater. Groundwater, river water or bank-filtered groundwater accounts for most of the differences.
• Step 3: request the quality report from your own company. These publish hardness, acidity and measured substances per production location, usually updated quarterly. We show how to read such a report using Vitens (Dutch drinking water company) water quality as an example.

A test strip from a webshop measures hardness and acidity roughly, but says nothing about PFAS, medicine residues or microplastics. For those substances you depend on measurements from your water company and the RIVM, and that is exactly what we advise customers to check before buying anything.

Frequently asked questions

Conclusion

There is no worst tap water in the Netherlands. All ten drinking water companies supply water that meets statutory requirements, and the RIVM ranks the quality among the best in the world. The ranking where the Netherlands sits at the bottom concerns surface water, not your tap.

What does vary per region are three things. The source: sixty percent of drinking water comes from groundwater, in the west it is river water. The pressure on that source: the western Netherlands has the highest PFAS concentrations, the south on sandy and loess soils has the biggest nitrate challenge, with 34 designated vulnerable groundwater protection areas. And hardness, which you notice on your kettle.

Anyone wanting to filter on that basis should look at technique, not fear. The PureFilter Mineral+ costs €149.00 including the first filter, is NSF-certified to 42, 53, 61 and 372, removes more than 100 contaminants, and you install it in 5 to 10 minutes without a plumber, using a single pair of water pump pliers. The replacement filter costs €65.00 and lasts around twelve months for 1 to 3 people, around six months for 4 to 6 people: less than one cent per litre. With 40 days of free returns and a 5-year warranty, you can calmly check at home whether you taste the difference.