Evides drinking water: how hard is it and what does it cost?

Reading time: about 16 minutes

Who is Evides and where does it supply water?

Evides Waterbedrijf supplies drinking water 24 hours a day to 2.5 million consumers and businesses in three areas: the south-west of Zuid-Holland, the whole province of Zeeland and the south-west of Noord-Brabant, the Brabantse Wal. Its head office is in Rotterdam.

That supply area is unusually varied. In Rotterdam, Dordrecht and Spijkenisse the water comes from a river. On Schouwen-Duiveland and Goeree-Overflakkee it comes from the dunes. In Bergen op Zoom and Ossendrecht it comes from deep groundwater. Three different sources, three different compositions, and so three different answers to the question of how hard your water is.

That is the most important thing to know about Evides, and it is exactly what most overview pages leave out: there is no single figure that is correct for the whole Evides area. A page that says Evides water is 7.8 °dH has taken an average from Rotterdam and pasted it onto Zeeland.

You see the same pattern with other water companies. Anyone living in Zuid-Holland-Zuid sometimes gets Evides and sometimes the drinking water from Oasen (another Dutch water company), and in Noord-Brabant the boundary with the water hardness of Brabant Water (also a Dutch water company) runs straight through the province. For the city of Rotterdam itself we have a separate piece: the tap water in Rotterdam. This page is about the company and its whole supply area.

Where does Evides water come from?

From three sources, and the largest is surface water. Evides takes in river water from the Maas (Meuse) and pumps it to the Brabantse Biesbosch, where three linked storage reservoirs are located: De Gijster, Honderd en Dertig and Petrusplaat.

That reserve does something a groundwater pumping station cannot. As soon as something is wrong with the Meuse, a silt wave after heavy rain, an extra discharge or an industrial incident, Evides simply switches off the intake pumps. In Eijsden in Limburg and Keizersveer in Noord-Brabant, continuous measurements of the river quality are taken, and the pumps only come back on once the pollution has flowed past the intake. With eighty million cubic metres in reserve, you can keep that up for weeks.

The second source is dune water. Evides takes in surface water from the Haringvliet, pre-treats it in Ouddorp and then introduces it into the soil of the dune areas. It slowly seeps away via ponds and canals, and after at least 30 days in the dune soil it is pumped up again and treated further.

The third source is groundwater. On the Brabantse Wal, Evides pumps up water from 30 to 120 metres deep and treats it at the Halsteren, Huijbergen and Ossendrecht sites. In Dordrecht, groundwater is extracted at a number of places and treated at the Baanhoek production site, after which it is mixed with drinking water made from Meuse water.

According to the RIVM (the Dutch National Institute for Public Health and the Environment), about 60% of Dutch drinking water nationally comes from groundwater. Evides is therefore on the other side of that split, and that explains part of what follows on PFAS. How the different purification techniques compare, and which filter type suits water from the Meuse and the dunes, can be found on our overview page.

How hard is Evides water?

Here is the figure you are missing everywhere else. In the last storage reservoir, Evides applies partial softening to 8.5 degrees German hardness, or 1.5 millimoles per litre. That is not an estimate from a comparison site but the water company’s own process description.

At 8.5 °dH, the softened Meuse water therefore sits just in the medium category, close to the border with soft. That is deliberate: softening to zero would strip the minerals from your drinking water, and nobody is happy about that. Evides gives as its reason for softening that you get less limescale and need less detergent.

But that figure does not apply to the whole area, and that is the point. Evides itself writes that the hardness can differ greatly per production site because of soil structure, groundwater flow and agriculture. Specifically:

If you live in the dune area, your water is therefore harder than the area average, and that is not a fault but geology. How that plays out nationally can be read in water hardness per municipality and in hard water in the Netherlands.

There is one limit that is almost never mentioned and that you should know before you start softening yourself: the Drinking Water Decree (Drinkwaterbesluit) prescribes that softened drinking water that you supply to third parties via a collective pipe network may not be reduced below 5.6 °dH. So the legislator itself believes there should be a floor under the hardness.

Looking up your water hardness by postcode

Because it differs per production site, your own postcode is the only figure that matters to you. You will have it in two minutes.

• Go to the my water hardness page of Evides and enter your postcode. You get the hardness of the production site that serves your address.
• If you want to see the full composition, click through to the water quality data per production site. The measured levels of minerals and salts are listed there too.
• Hold your result against the scale: below 8 °dH is soft, 8 to 12 is medium. Above 10, descaling your kettle and coffee machine becomes a recurring chore.
• Set your dishwasher and washing machine to the value you found. It is in the manual and saves salt and detergent with every wash.

Be careful with third-party overview pages. For Rotterdam we come across values of 7.8 °dH, of 8.5 °dH and of “between 7 and 10”, all presented as the figure. They do not even contradict each other, they just measure different things at different moments. The postcode tool of your own water company is the only source that is correct for your tap.

What does drinking water from Evides cost in 2026?

According to Evides, in 2026 you pay €1.320 per cubic metre and €101.05 standing charge per year, both including 9% VAT. On top comes the tap water tax (Belasting op Leidingwater): €0.476 per cubic metre, up to a consumption of 50,000 cubic metres per year. One cubic metre is 1,000 litres.

Work it out for a household that uses 100 cubic metres a year: 100 times €1.796 is €179.60, plus €101.05 standing charge is about €281 per year, or roughly €23.40 per month. Per litre that comes to €0.0028 all-in. A litre of bottled water costs €0.40 to €1.00, so you pay a factor of 140 to 350 more for it. The broader calculation is in what a cubic metre of water costs.

Two figures that Evides itself provides and that you will not read anywhere else. First: 64% of customers use less than 100 cubic metres per year, so for the majority the bill comes out lower than the example above. Second: if Evides does not know your consumption, it estimates you at 130 cubic metres per year. At that consumption you end up at about €335 per year. If your instalment feels high, that is often the explanation: you are paying according to an estimate, not according to your meter.

Is Evides expensive? The honest calculation

It is one of the most frequently asked questions about this company, and the answer is more nuanced than the question suggests. The Evides rates actually went down in 2026.

For a household of 100 cubic metres, that saves about €15 per year compared with 2025. Evides explains the decrease by a one-off cost item that was included in the 2025 rates and not in 2026.

That leaves the comparison with the neighbours. Brabant Water charges €1.51 all-in per cubic metre and €95.75 standing charge in 2026; at Evides that is €1.796 all-in and €101.05. On 100 cubic metres the difference is about €34 per year, roughly €2.83 per month. That is a real difference and at the same time a small amount, and there is a logical reason behind it: making drinking water from river water, with storage reservoirs, intake stops and multi-stage treatment, simply costs more than pumping up deep groundwater that comes out of the soil already clean.

What does make a difference in your own wallet is your consumption. At PureFilter we see that customers who were on bottled water barely see their water bill rise after switching to filtered tap water, while the grocery bill gets noticeably lighter. Work out your own needs at how much water you need per day.

Is there PFAS in Evides water?

Traces, and the company is open about it. Evides writes that it finds traces of PFAS in the surface water of the Meuse and the Haringvliet and that it also sees very small amounts in the drinking water. All values are below the applicable standards and below the new European drinking water standard that came into force in January 2026.

Two limit values are being mixed up, and that is the source of nearly all the confusion on this subject.

Since early 2022, Evides has been measuring using improved methods in the sources and in the treated drinking water, and it publishes the measurement series per production site: Baanhoek, Berenplaat, Braakman, Kralingen, Haamstede, Ouddorp, Huijbergen, Ossendrecht, Halsteren and Midden-Zeeland. The conclusion is that the supplied drinking water meets the assessment values at all sites.

The RIVM adds two things that are relevant to the Evides area. Drinking water from surface water contains more PFAS than drinking water from groundwater, and people take in about three times as much PFAS through food as through drinking water. You have little grip on your groceries, but you do on your tap. Background on this group of substances is in PFAS and forever chemicals, where measurements have been taken in the Netherlands is shown on the PFAS map of the Netherlands, and which techniques actually hold back PFAS is covered on our PFAS page.

Let us stay honest about the direction: Evides itself argues for a national and European total ban on the production, emission and use of PFAS, on the grounds that what is not in the source does not need to be removed by treatment either. That is a position we fully support.

Medicine residues, contrast agents and pesticides

Water from a river carries the traces of everything that happens upstream. Evides therefore publishes, per substance group, what it finds and where the health-based guideline value lies. The figures are reassuring, and at the same time they are the reason people filter.

Put that in proportion. Someone who takes metformin swallows 390 to 4,000 milligrams per day; in the drinking water the figure is at most 0.0009 milligrams per litre. The difference is a factor of four hundred thousand to well over four million. Anyone who uses these figures to scare you is not doing the maths.

What is true is that the list gets longer as the measuring equipment gets better. Evides now measures in nanograms, a billionth of a gram, and measures more substances than is legally required. What medicine residues in tap water and filtering pesticides from tap water mean in practice is worked out in those two pieces.

What Evides itself says about home water softeners

This is one of the most useful pieces of text on the whole Evides site, and almost nobody links to it. The water company warns about four concrete things with a home softener based on ion exchange.

• Bacterial growth. Any treatment of tap water can affect its quality. Filters must be cleaned or replaced in time, and the synthetic resin must regenerate in time.
• Pressure loss. A softener with the required protection costs about 70 kPa, or 0.7 bar. You notice that in your shower.
• Ventilation in the meter cupboard. An extra appliance disturbs the airflow, and with too little ventilation the tap water warms up. Warm standing water is exactly what you do not want.
• Quality certificate. The appliance must have a Kiwa ATA or comparable certificate to comply with the Regulation on materials and chemicals for drinking and hot tap water supply (Regeling materialen en chemicaliën drink- en warmtapwatervoorziening).

A softener and a water filter are often confused, although they do something quite different. A softener changes the hardness of all your water, including water you do nothing with, and swaps calcium and magnesium for sodium. An under-sink filter treats only the water that comes out of your kitchen tap and leaves the rest of your installation alone. The full comparison is in water softener or water filter, and how to tackle limescale without stripping your water bare is in filtering limescale from tap water.

What Evides does not control

A water company’s responsibility stops at the water meter. Behind it your installation begins, and there are four things there that no treatment site can solve for you.

Lead pipes. With lead water pipes, Evides advises running the tap for two minutes before using the water to drink or cook, and in that case recommends that women who want to become pregnant, pregnant women and children up to and including seven years old drink bottled water at home. In the pre-war districts of Rotterdam, Dordrecht and Vlissingen that is not theory. What lead does is covered in filtering lead from tap water.

Warm tap water. Evides advises against regularly drinking warm tap water, because copper from pipes and boiler vessels can dissolve in it and taps can release nickel, chromium and cadmium. Drawing cold water and then heating it is the advice. More on this at drinking warm tap water.

White or brown water. According to Evides, white water is caused by air bubbles after works and is not harmful; leave a glass to stand for a moment and it clears. The explanation is at white water from the tap.

Boil-water advisory. After a pipe burst or after works, the quality cannot temporarily be guaranteed. Evides itself points out that a boil-water advisory always lasts several days, because water samples have to be analysed in a laboratory. A water filter never replaces such an advisory: NSF 42, 53, 61 and 372 concern chemical substances and materials, not microbiological purification. What you do instead is covered in a boil-water advisory for tap water.

Do you need a water filter in the Evides area?

No. Evides says so itself, and we would rather write it ourselves than have you read it elsewhere: the water fully meets all the requirements of the Water Supply Act (waterleidingwet), and filtering is not necessary for that. A filter shop that tells you the tap water in Rotterdam or Zeeland is not good deserves your distrust.

Evides does add a sentence that you should take with you if you filter anyway: maintain the filter regularly to prevent bacterial growth. That is not a detail but the core of the difference between a good and a bad filter, and it is exactly why how often you replace a water filter is a more important question than which brand you buy.

Why people in this area filter anyway comes down to three reasons, none of which is about safety.

• The source. River water simply carries more traces than deep groundwater. Evides removes a great deal, but not everything, and the company says so too.
• Taste and limescale. At 8.5 °dH you notice limescale in your kettle and on your shower glass, and in the dune area more than that. For coffee it is also a matter of taste, see a filter in your coffee machine.
• The sum of everything. The RIVM advises reducing total PFAS intake. You have more grip on that at your tap than on your diet, even if your starting point is already good.

Our under-sink water filter removes all 40 chemicals tested, from 75% to 99.97% from the water in five steps, including PFAS, microplastics, heavy metals, fluoride and nitrate, and then adds back calcium, magnesium and potassium via Swedish Mineral Rock™. It is tested by Equinox Labs, an independent laboratory (2026). A household osmosis system usually skips that last step and leaves you with bare water; why that matters is covered in osmosis water, healthy or unhealthy. If you have a Quooker (a boiling-water tap), it does not replace filtering: see water filter and Quooker.

Comparison: softener, filter jug, osmosis or filter

The PureFilter Mineral+ costs €149.00 including the first filter. A replacement filter costs €65.00 and lasts about twelve months for 1 to 3 people, and about six months for 4 or more. The duo with two cartridges costs €115.00. Converted, that is €48 per year with the Filter Plan for 1 to 3 people. If you would rather not think about it, the Filter Plan automatically sends the cartridges on time for €48.00 or €86.00 per delivery.

Installation takes 5 to 10 minutes: you do not need a plumber, you use one water pump pliers to connect to the cold water supply, and later you change the cartridge with the supplied key. Step by step, it is in the guide to installing a water filter. The full overview of the under-sink filters we sell is in the web shop, and how the models compare is covered in the best water filter.

Frequently asked questions

Conclusion

Anyone who gets Evides drinking water from the tap is, in most cases, drinking Meuse water that has spent two to three months in the Biesbosch and has been softened to 8.5 degrees German hardness in the last storage reservoir. In the dune area it is harder, and on the Brabantse Wal it comes from groundwater 30 to 120 metres deep. So there is no single figure that is correct for the whole area, and your own postcode is the only thing that counts.

The figures to remember: €1.320 per cubic metre in 2026 plus €0.476 tax and €101.05 standing charge, together about €281 per year at 100 cubic metres. That is a decrease of some €15 compared with 2025. PFAS is measured in the sources and in the drinking water and stays below the European standard of 100 nanograms per litre at all ten production sites. Medicine residues are found at concentrations at least a factor of four hundred thousand below a daily dose.

In the Evides area you therefore do not filter because the water is bad, because it is not. You do it for the limescale in your kettle, for the taste, or because you want to take control of the last metres from the water meter to the glass yourself. And if you do, keep to the same order that Evides follows in its own treatment: first remove what does not belong in it, then keep what you want to retain. And replace your filter on time, because that is the only thing that can make a filter worse than no filter.