pfasnearmeDrinking water quality from official sources

PFAS in the tap water of Mons (Belgium): 1.6 ng/L, 3.2x our 0.5 ng/L benchmark

Last PFAS check: · Source: SPW-ARNE / SWDE

PFAS in drinking water

3.2× above our health benchmark

Amount found in the water 1.6 ng/L 0.0016 µg/L · the 4 most harmful PFAS (PFAS-4)
Our health benchmark 0.5 ng/L

0.5 ng/L is our benchmark, not an official limit. Same EFSA method as Sweden, Denmark and the Netherlands, but stricter. It's a yearly average, compared here with the latest check.

How we chose 0.5 ng/L

The PFAS figures come from the sample of 17 December 2025 in distribution zone ZW1363 (SWDE), one of the 13 zones serving Mons.

More about this result
Target value in Belgium (binding from 2028) no verdict
finer than the lab's detection limit 1.6 ng/L · Limit: 4 ng/L
Legal limit in Sweden (since 2026) no verdict
finer than the lab's detection limit 1.6 ng/L · Limit: 4 ng/L
Limit in Denmark (since 2021) no verdict
finer than the lab's detection limit 1.6 ng/L · Limit: 2 ng/L
Limit in Germany (from 2028) within the limit
below this limit 1.6 ng/L · Limit: 20 ng/L

The US also limits PFOA and PFOS to 4 ng/L each, per substance.

Substances below the detection limit count as 0, so the real total may be higher.

One of these four, PFOA, is classified as causing cancer in humans by the WHO's cancer research agency (IARC).

More PFAS than in 60% of the cities we track

Legal limit (Belgium and EU) within the limit
2 % of the EU limit 0.0016 µg/L · Limit: 0.1 µg/L

checked on 17 December 2025

20 PFAS (see each substance)
PFAS substance Value
PFHxS 0.0016 µg/L
PFOS <0,001 µg/L
PFOA <0,001 µg/L
PFHxA <0,001 µg/L
PFHpA <0,001 µg/L
PFBA <0,001 µg/L
PFPeA <0,001 µg/L
PFNA <0,001 µg/L
PFDA <0,001 µg/L
PFUnDA <0,001 µg/L
PFDoDA <0,001 µg/L
PFTrDA <0,001 µg/L
PFBS <0,001 µg/L
PFPeS <0,001 µg/L
PFHpS <0,001 µg/L
PFNS <0,001 µg/L
PFDS <0,001 µg/L
PFUnDS <0,001 µg/L
PFDoDS <0,001 µg/L
PFTrDS <0,001 µg/L

Above our health benchmark. Get new results by email below.

Legal limit (Belgium and EU)
1.6 ng/L sum of 20 PFAS, below the 100 ng/L limit
Last PFAS test
17 December 2025
Water supplier
IDEA, SWDE

In Mons, the 4 most closely watched PFAS (PFAS-4) add up to 1.6 ng/L (0.0016 µg/L) at the latest PFAS check on 17 December 2025. That's 3.2 times our 0.5 ng/L health benchmark, but below Sweden's legal limit of 4 ng/L. Sum of 20 PFAS: 1.6 ng/L (0.0016 µg/L), below the EU legal limit (100 ng/L). 101 checks since 4 September 2023: PFAS-4 up to 6 ng/L, sometimes below the detection limit, averaging at least 0.21 ng/L over 12 months (non-detects as 0). Source: SPW-ARNE / SWDE – Etat des lieux du monitoring PFAS dans les eaux distribuées (sept. 2023 – déc. 2025).

Details and sources
Water supplier: IDEA, SWDE Latest water check: 17 December 2025 Data updated on

PFAS over time in Mons

101 PFAS checks since 4 September 2023, values as published. Samples come from 13 distribution networks. The trend refers to the network “ZW1177 (SWDE)”.

0.5 ng/L6 ng/L04 September 202317 December 2025
PFAS-4 sum per check in ng/L. Dashed line: pfasnearme's 0.5 ng/L benchmark. Hollow dots: below the detection limit.
DatePFAS-4Sum of 20 PFASNetwork
1.6 ng/L1.6 ng/LZW1363 (SWDE)
< 4 ng/L< 23.5 ng/LZW1177 (SWDE)
< 4 ng/L< 20 ng/LZW1177 (SWDE)
< 4 ng/L< 20.5 ng/LZIDEA1 (IDEA)
3.4 ng/L3.4 ng/LZW1177 (SWDE)
< 4 ng/L1 ng/LZW1171 (SWDE)
< 4 ng/L< 20 ng/LZW1172 (SWDE)
< 4 ng/L< 20 ng/LZW1177 (SWDE)
< 4 ng/L< 20 ng/LZW1175 (SWDE)
< 4 ng/L< 20 ng/LZW1476 (SWDE)
< 4 ng/L< 20 ng/LZW1170 (SWDE)
< 4 ng/L1 ng/LZW1177 (SWDE)
Show the 89 earlier checks (back to 4 September 2023)
< 4 ng/L< 20.5 ng/LZW1173 (SWDE)
4 ng/L15.2 ng/LZW1175 (SWDE)
< 4 ng/L< 20.5 ng/LZW1476 (SWDE)
< 4 ng/L1 ng/LZW1177 (SWDE)
< 4 ng/L1 ng/LZW1177 (SWDE)
< 4 ng/L< 20 ng/LZW1177 (SWDE)
< 4 ng/L< 20 ng/LZW1177 (SWDE)
< 4 ng/L< 23 ng/LZIDEA1 (IDEA)
1 ng/L1 ng/LZW1486 (SWDE)
< 4 ng/L< 20.5 ng/LZIDEA9 (IDEA)
< 4 ng/L< 23 ng/LZW1177 (SWDE)
< 4 ng/L< 20.5 ng/LZW1476 (SWDE)
5 ng/L21 ng/LZW1175 (SWDE)
< 4 ng/L1 ng/LZW1177 (SWDE)
< 4 ng/L< 20.5 ng/LZW1170 (SWDE)
2 ng/L2 ng/LZIDEA1 (IDEA)
< 4 ng/L< 23 ng/LZW1177 (SWDE)
< 4 ng/L< 20 ng/LZIDEA1 (IDEA)
< 4 ng/L< 26 ng/LZW1177 (SWDE)
< 5 ng/L< 26 ng/LZW1177 (SWDE)
< 4 ng/L< 26 ng/LZW1177 (SWDE)
< 4 ng/L< 26 ng/LZW1177 (SWDE)
< 4 ng/L< 21 ng/LZIDEA10 (IDEA)
< 4 ng/L< 26 ng/LZW1172 (SWDE)
< 4 ng/L< 27 ng/LZW1172 (SWDE)
< 4 ng/L< 27 ng/LZW1476 (SWDE)
< 4 ng/L< 27 ng/LZW1171 (SWDE)
< 4 ng/L< 27 ng/LZW1173 (SWDE)
< 4 ng/L< 27 ng/LZW1175 (SWDE)
< 4 ng/L< 26 ng/LZW1176 (SWDE)
< 4 ng/L< 25 ng/LZW1476 (SWDE)
< 4 ng/L< 20 ng/LZIDEA1 (IDEA)
4 ng/L10 ng/LZIDEA10 (IDEA)
< 4 ng/L< 20 ng/LZIDEA9 (IDEA)
< 4 ng/L< 23 ng/LZW1476 (SWDE)
6 ng/L13 ng/LZIDEA10 (IDEA)
< 4 ng/L< 25 ng/LZW1172 (SWDE)
< 4 ng/L< 23 ng/LZW1171 (SWDE)
< 4 ng/L< 23 ng/LZW1172 (SWDE)
< 4 ng/L< 22 ng/LZW1476 (SWDE)
< 4 ng/L4 ng/LZW1175 (SWDE)
< 4 ng/L< 25 ng/LZW1177 (SWDE)
< 4 ng/L< 25 ng/LZW1363 (SWDE)
< 4 ng/L< 23 ng/LZW1170 (SWDE)
3 ng/L5 ng/LZIDEA10 (IDEA)
< 4 ng/L< 25 ng/LZW1476 (SWDE)
< 4 ng/L< 22 ng/LZW1172 (SWDE)
< 4 ng/L< 25 ng/LZW1177 (SWDE)
5 ng/L15 ng/LZW1175 (SWDE)
< 4 ng/L< 22 ng/LZIDEA1 (IDEA)
< 4 ng/L< 24 ng/LZW1173 (SWDE)
< 4 ng/L< 23 ng/LZIDEA1 (IDEA)
4 ng/L10 ng/LZW1175 (SWDE)
< 4 ng/L< 24 ng/LZW1486 (SWDE)
< 4 ng/L< 25 ng/LZIDEA1 (IDEA)
< 4 ng/L2 ng/LZIDEA1 (IDEA)
< 4 ng/L< 25 ng/LZW1170 (SWDE)
< 4 ng/L< 25 ng/LZW1172 (SWDE)
< 4 ng/L< 25 ng/LZW1476 (SWDE)
< 4 ng/L2 ng/LZW1177 (SWDE)
< 4 ng/L< 22 ng/LZW1176 (SWDE)
< 4 ng/L< 22 ng/LZW1363 (SWDE)
< 8 ng/L< 40 ng/LZW1171 (SWDE)
< 8 ng/L< 40 ng/LZW1172 (SWDE)
< 8 ng/L1 ng/LZW1173 (SWDE)
< 8 ng/L1 ng/LZW1175 (SWDE)
< 8 ng/L1 ng/LZW1476 (SWDE)
< 8 ng/L< 40 ng/LZW1176 (SWDE)
< 4 ng/L< 25 ng/LZW1172 (SWDE)
< 4 ng/L< 23 ng/LZW1173 (SWDE)
< 4 ng/L< 23 ng/LZW1171 (SWDE)
2 ng/L11 ng/LZW1175 (SWDE)
< 4 ng/L< 23 ng/LZW1177 (SWDE)
< 4 ng/L< 23 ng/LZW1363 (SWDE)
< 4 ng/L< 23 ng/LZW1476 (SWDE)
< 4 ng/L< 21 ng/LZIDEA9 (IDEA)
< 4 ng/L< 22 ng/LZIDEA1 (IDEA)
3 ng/L6 ng/LZIDEA10 (IDEA)
< 4 ng/L< 20 ng/LZW1176 (SWDE)
< 4 ng/L< 22 ng/LZW1172 (SWDE)
< 4 ng/L< 22 ng/LZW1172 (SWDE)
< 4 ng/L< 22 ng/LZW1486 (SWDE)
< 4 ng/L< 24 ng/LZW1170 (SWDE)
< 4 ng/L< 24 ng/LZW1173 (SWDE)
< 4 ng/L< 22 ng/LZW1476 (SWDE)
< 4 ng/L< 22 ng/LZW1171 (SWDE)
< 4 ng/L< 21 ng/LZW1177 (SWDE)
< 4 ng/L< 21 ng/LZW1363 (SWDE)
5 ng/L15 ng/LZW1175 (SWDE)

“<” means not detected, the figure being the detection limit. “–” means not published. Labs have only reported the PFAS-4 sum (SANDRE code 9268) since autumn 2025. How to read a PFAS result

What the latest check found

The authorities have not published an overall verdict for this water.

Frequently asked questions

Is tap water in Mons safe to drink?

All the values shown here (17 December 2025) are within the legal limits, but the authorities have not published an overall verdict for this water.

How high are PFAS levels in Mons's drinking water?

The total of 20 PFAS ("forever chemicals") was last measured at 1.6 ng/L. The EU limit is 100 ng/L, so this water is at 2 % of the limit. (below the EU limit)

Does the water in Mons also meet the strictest limits in Europe?

Yes. Even against Europe's strictest legal limit, Sweden's 4 ng/L in force since 2026, the measured value of 1.6 ng/L stays below.

Are PFAS levels rising in Mons's tap water?

Too few quantified checks to say (1 since 4 September 2023). pfasnearme adds each new publication weekly; a trend needs at least three quantified values.

Which PFAS limits apply in Belgium?

Belgium applies the EU limit of 100 ng/L for the sum of 20 PFAS as binding law (Flemish Drinkwaterbesluit of 2023, Walloon Code de l'eau since February 2025). For the four most harmful PFAS (PFAS-4) all three regions set a target of 4 ng/L that becomes binding in 2028. This site's 0.5 ng/L benchmark is stricter than both.

How hard is the water in Mons?

No hardness value is available for Mons in this source.

Where does this data come from?

All values come from official publications: SPW-ARNE / SWDE – Etat des lieux du monitoring PFAS dans les eaux distribuées (sept. 2023 – déc. 2025). Retrieved on 28 September 2026.

Same water network

Same distribution network as Mons, so in principle the same water.

Frameries
PFAS-4: below 4 ng/L
Quaregnon
PFAS-4: below 4 ng/L
Saint-Ghislain
PFAS-4: below 4 ng/L
La Louvière
PFAS-4: below 4 ng/L
Soignies
PFAS-4: below 4 ng/L
Le Roeulx
PFAS-4: 1.6 ng/L
Jurbise
PFAS-4: below 4 ng/L
Lens
PFAS-4: below 4 ng/L

Nearby cities

The closest to Mons on this site.

Quévy
PFAS-4: below 4 ng/L 10 km away
Colfontaine
PFAS-4: below 4 ng/L 10 km away
Estinnes
PFAS-4: 1.6 ng/L 12 km away
Boussu
PFAS-4: below 4 ng/L 13 km away
Dour
PFAS-4: below 4 ng/L 15 km away

Data source
SPW-ARNE / SWDE – Etat des lieux du monitoring PFAS dans les eaux distribuées (sept. 2023 – déc. 2025)
https://environnement.wallonie.be/home/gestion-environnementale/environnement-sante/pfas
Retrieved
28 September 2026
Supply networks
ZIDEA1 (IDEA), ZIDEA10 (IDEA), ZIDEA9 (IDEA), ZW1170 (SWDE), ZW1171 (SWDE), ZW1172 (SWDE), ZW1173 (SWDE), ZW1175 (SWDE), ZW1176 (SWDE), ZW1177 (SWDE), ZW1363 (SWDE), ZW1476 (SWDE), ZW1486 (SWDE)

Wallonia: Service public de Wallonie (SPW-ARNE) with SWDE, PFAS monitoring of distributed water, one row per sample and distribution zone, September 2023 to December 2025. The reuse licence for this document is still to be confirmed with SPW; attributed to SPW-ARNE and SWDE meanwhile.

Limits in Belgium. Belgium applies the EU limit of 100 ng/L for the sum of 20 PFAS as binding law (Flemish Drinkwaterbesluit of 2023, Walloon Code de l'eau since February 2025). For the four most harmful PFAS (PFAS-4) all three regions set a target of 4 ng/L that becomes binding in 2028. This site's 0.5 ng/L benchmark is stricter than both.

Résultats du monitoring PFAS des eaux distribuées (SPW-ARNE, coordination SWDE), une ligne par prélèvement et zone de distribution (ZDE) ; la commune est desservie par 13 zones (ZIDEA1, ZIDEA10, ZIDEA9, ZW1170, ZW1171, ZW1172, ZW1173, ZW1175, ZW1176, ZW1177, ZW1363, ZW1476, ZW1486). Valeurs publiées en ng/L, converties en µg/L ; un « < » indique que tous les composés étaient sous la limite de quantification. Licence de réutilisation non vérifiée pour ce document (les données ouvertes du SPW sont normalement CC BY 4.0) ; attribution SPW-ARNE et SWDE en attendant confirmation.

This site is a data project, not an official source. If in doubt, check with your water supplier or local authority.