PFAS in the tap water in Flemish Brabant
The tap water in Flemish Brabant meets the legal standard. In most of the province it also meets the stricter Flemish target. But in some areas, such as the south of Leuven and the eastern Brussels periphery, it contains more PFAS than that target. Here you can read what that means and what you can do yourself.
See the figuresShop ZeroWaterHow much PFAS is in the tap water in Flemish Brabant?
- The tap water in Flemish Brabant meets the legal standard (100 nanograms per litre for 20 PFAS).
- In the south of Leuven, the eastern Brussels periphery and around Londerzeel it is above the Flemish target.
- In the Hageland and the east of the province there is hardly any PFAS: often below 1 nanogram per litre.
- De Watergroep says: you can keep drinking tap water. It wants to meet the target everywhere by 2028.
Figures per area
Many municipalities are spread over several supply areas. The figure for your street may therefore differ from the rest of your municipality.
| Area | Median* | Highest* | Company |
|---|---|---|---|
| South of LeuvenLeuven (Heverlee, Haasrode), Bierbeek, Lubbeek (Pellenberg), Oud-Heverlee, Boutersem (Bost) | 18 | 29 | De Watergroep |
| Eastern Brussels peripheryKraainem, Wezembeek-Oppem, Tervuren, Zaventem (Voskapel), Steenokkerzeel, parts of Kortenberg and Grimbergen (Strombeek-Bever) | 6.5 | 10 | De Watergroep |
| Zaventem airport areaZaventem (airport), Machelen, parts of Vilvoorde, Kraainem and Wezembeek-Oppem | Above the target, according to the Flemish government. No exact figure published. | Farys | |
| Londerzeel and MeiseLonderzeel (Steenhuffel), Meise (Imde, Rossem, Nerom) | 5.5 | 6 | De Watergroep |
| Kapelle-op-den-BosKapelle-op-den-Bos (Nieuwenrode, Ramsdonk), Londerzeel (centre), Meise (Westrode) | 4 | 7 | De Watergroep |
| Zenne valleyHalle (west), Sint-Pieters-Leeuw, Sint-Genesius-Rode | 4 | 6 | De Watergroep |
| North of LeuvenHerent, Holsbeek, Rotselaar, parts of Leuven, Lubbeek, Bierbeek and Oud-Heverlee | 3 | 24 | De Watergroep |
| West of BrusselsAsse, Affligem, Dilbeek, Liedekerke, Ternat, Wemmel, Drogenbos, Linkebeek | 2.5 | 5.7 | Farys |
| North-west of BrusselsMerchtem, Opwijk, Meise (Wolvertem), Grimbergen (Humbeek), Zemst | 2 – 3 | 3 | De Watergroep |
| Halle (east)Essenbeek, Buizingen, Hallerbos. Temporary treatment plant since 2024 | 0 | 24 | De Watergroep |
| PajottenlandGooik, Galmaarden, Herne, Lennik, Pepingen, Roosdaal, Beersel | 0 – 2 | 6 – 11 | De Watergroep, Farys |
| Hageland and the rest of the provinceTienen, Landen, Diest, Aarschot, Hoegaarden, Zoutleeuw, Scherpenheuvel-Zichem, Tremelo, Haacht, Keerbergen, Vilvoorde, Overijse, Huldenberg, Hoeilaart, Bertem and more | 0 – 1.5 | 0 – 7 | De Watergroep |
Diest (Hoste) is an exception in the east: median 5, highest 6. Want to know the figure for your address? Look it up with your drinking water company, for example De Watergroep (dewatergroep.be/kwaliteit).
Why Flemish Brabant in particular?
Most tap water in Flemish Brabant comes from De Watergroep, which makes it mainly from groundwater. In the east of the province, that groundwater contains hardly any PFAS.
Around Leuven it is different. The groundwater near Heverlee and Haasrode contains more PFAS. According to the Flemish government, this comes from an old landfill and a fire at a company in Haasrode in 1985, where firefighting foam with PFAS was used. De Watergroep has switched off the most polluted wells and is working on extra treatment.
In the west and around Brussels, part of the water is bought in, for example water from Wallonia via Vivaqua. That water sometimes contains more PFAS. In Halle, De Watergroep installed a temporary treatment plant in 2024. Since then, the median there is below the target again. A new supply via the Farys network is planned.
* Sum of the four PFAS in the target (PFOA, PFOS, PFNA and PFHxS), in nanograms per litre. Median and highest value per supply area, measured in the network and at the tap in 2024. Values below the reporting limit count as 0. Source: VMM (Flanders Environment Agency), Drinking water quality 2024, annex 2. Levels vary by street and by measurement.
What is PFAS?
PFAS is a large group of man-made substances. They are found in many things you use every day.
- Non-stick pans
- Rain jackets and outdoor clothing
- Food packaging
- Cosmetics and firefighting foam
Why is it called a ‘forever chemical’?
- PFAS hardly break down in nature.
- They enter rivers and groundwater through factories and products.
- That water is also used to make drinking water.
- They stay in your body for a long time.
Why PFAS deserves attention
EFSA, the European Food Safety Authority, says: part of the European population takes in more PFAS than is good for their health. This comes mainly from food, but also from drinking water.
It builds up
Your body clears PFAS only slowly. Small amounts add up over the years.
Effect on your immune system
According to EFSA, even small amounts of PFAS can make your immune system work less well.
The target is stricter than the law
Flanders aims for 4 nanograms per litre for four PFAS. The law is less strict. Below you can read the difference.
Law and target: what's the difference?
There are two numbers you may read about. They don't measure the same thing, but this is how it works:
- The law (EU): a maximum of 100 nanograms per litre for 20 PFAS combined. It applies across the EU from 12 January 2026. Flemish tap water meets this standard.
- The Flemish target: 4 nanograms per litre for four PFAS combined (PFOA, PFOS, PFNA and PFHxS). Drinking water companies should reach it by January 2028. It is based on EFSA advice.
The target is stricter because it looks at the four PFAS that have been studied most and that EFSA considers most important for your health.
Good to know
- Tap water in Flanders is safe to drink, say VMM and De Watergroep.
- Drinking water made from groundwater usually contains less PFAS than water made from surface water such as rivers and canals.
- Every Flemish drinking water company has made a plan to reach the target.
- Boiling does not remove PFAS from your water.
ZeroWater filters PFAS
Just keep drinking tap water. Want to take in less PFAS through your water? Then a certified filter is a simple extra step.
less PFAS in your water
This percentage applies to PFOA and PFOS, the two best-known and most studied PFAS. The ZeroWater 5-stage filter has been tested for these to the NSF/ANSI 53 standard and certified by the independent institute IAPMO. View the certificate.
Tested, certified
Not a promise, but an independently tested result. Tested with far more PFOA and PFOS than is found in Belgian tap water.
More than just PFAS
The filter is also certified for lead, chromium-6, mercury and chlorine. That makes your water taste purer too.
See it for yourself 000 PPM
Every jug comes with a TDS meter. It shows how pure your water is. Does it show 006? Then it's time for a new filter.
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Add to cartView product →Questions about PFAS in Flemish Brabant
Can I still drink the tap water in Flemish Brabant?
Yes. The tap water in Flemish Brabant meets the legal standard. VMM and De Watergroep say you can keep drinking tap water. Want to take in less PFAS? Then you can filter your water as an extra step.
Does ZeroWater filter all PFAS?
The honest answer: ZeroWater is certified for PFOA and PFOS, the two best-known PFAS. There are thousands of types of PFAS. We have no certificate for the other types, so we don't make any promises about them.
How much PFAS is in the water at my address?
That depends on your supply area. Customers of De Watergroep can look up the measurements for their address at dewatergroep.be/kwaliteit. Customers of Farys can find the water quality per municipality at farys.be.
Why is there more PFAS around Leuven?
The groundwater near Heverlee and Haasrode contains more PFAS. According to the Flemish government, this comes from an old landfill and a fire in 1985, where firefighting foam with PFAS was used. De Watergroep has switched off the most polluted wells and is working on extra treatment.
Does boiling or bottled water help?
Boiling does not remove PFAS from water. Bottled water creates a lot of plastic waste. A filter on your regular tap water is a simpler alternative.
How often should I replace the filter?
That depends on your tap water. The harder your water, the faster the filter fills up. Test your water with the TDS meter: when it shows 006, it's time for a new filter.
Know what you drink
Just tap water, but with less PFAS. For you and your family in Flemish Brabant.
Shop ZeroWaterReplacement filters- VMM (Flanders Environment Agency) – Drinking water quality 2024, report and annex 2 with the median and highest value per supply area (in Dutch). vmm.vlaanderen.be
- VMM – Is there PFOS or PFAS in tap water? (in Dutch). vmm.vlaanderen.be
- Flemish Parliament – answer to written question no. 49 on PFAS in drinking water, 2025 (in Dutch). vlaamsparlement.be
- Flemish Parliament – answer to written question no. 533 on the Parkabdij water abstraction in Leuven, 2025 (in Dutch). vlaamsparlement.be
- VRT NWS – De Watergroep reduces PFAS in tap water in Halle, April 2024 (in Dutch). vrt.be
- EFSA – PFAS in food: EFSA assesses risks and sets tolerable intake (2020). efsa.europa.eu
- EU Drinking Water Directive 2020/2184. eur-lex.europa.eu
- ZeroWater Performance Data Sheet, IAPMO certification to NSF/ANSI 53 and 42. View PDF
ZeroWater is certified for the reduction of PFOA and PFOS. Results were achieved under laboratory conditions; actual results may vary.