PFAS in Longpont's tap water: under 4 ng/L, none of the four main PFAS detected
Last PFAS check: · Source: Hub'eau
PFAS in drinking water
No PFAS detected
The lab sees nothing below 4 ng/L, 8 times our benchmark of 0.5 ng/L. Water above our benchmark would pass this check unnoticed.
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.
Sample taken in Chouy, on the same distribution network as Longpont (UDI DU NADON). The health authority samples one tap per network; a network carries the same treated water everywhere.
More about this result
The US also limits PFOA and PFOS to 4 ng/L each, per substance.
The lab detects each of the four substances from 1 ng/L upward. None reached that limit, so their total is below 4 ng/L rather than zero.
checked on 5 February 2026
20 PFAS (see each substance)
| PFAS substance | Value |
|---|---|
| Acide perfluoro tridecane sulfonique (PFTrDS) | <0,005 µg/L |
| Perfluorohexane sulfonate (PFHXS) | <0,001 µg/L |
| Acide perfluoro undecanoïque (PFUnA) | <0,001 µg/L |
| Acide perfluoropentane sulfonique (PFPS) | <0,001 µg/L |
| Acide perfluorobutanoïque (PFBA) | <0,002 µg/L |
| Acide perfluorohexanoïque (PFHXA) | <0,002 µg/L |
| Acide perfluoro undecane sulfonique (PFUnDS) | <0,002 µg/L |
| Acide perfluoroheptanoïque (PFHPA) | <0,001 µg/L |
| Acide perfluorononane sulfonique (PFNS) | <0,002 µg/L |
| Acide sulfonique de perfluorobutane (PFBS) | <0,001 µg/L |
| Acide perfluorodecane sulfonique (PFDS) | <0,001 µg/L |
| Acide perfluoro tridecanoique (PFTrDA) | <0,001 µg/L |
| Acide perfluoropentanoïque (PFPEA) | <0,001 µg/L |
| Acide perfluoro-octanoïque (PFOA) | <0,001 µg/L |
| Acide perfluorododécanoique (PFDoDA) | <0,001 µg/L |
| Acide perfluoroheptane sulfonique (PFHpS) | <0,002 µg/L |
| Acide perfluorododécane sulfonique (PFDoDS) | <0,001 µg/L |
| Acide perfluoro-decanoïque (PFDA) | <0,001 µg/L |
| Acide perfluoro-nonanoïque (PFNA) | <0,001 µg/L |
| Acide sulfonique de perfluorooctane (PFOS) | <0,001 µg/L |
None found. The lab sees nothing below 4 ng/L, so our 0.5 ng/L benchmark cannot be checked.
Water report for Longpont
Get new PFAS results for Longpont, with a short explanation. At most one update a week, only when there's something new.
- EU legal limit
- none detected sum of 20 PFAS below the detection limit, limit 100 ng/L
- Last PFAS test
- 5 February 2026
- Water supplier
- SYNDICAT DES EAUX DU SOISSONNAIS ET DU VALOIS
In Longpont, none of the 4 most closely watched PFAS (PFAS-4) was detected at the latest PFAS check on 5 February 2026. The total is below 4 ng/L, the sum of the detection limits and 8 times our 0.5 ng/L benchmark. Sum of 20 PFAS: <0,029 µg/L, below the EU legal limit (100 ng/L). Sampled in Chouy, on the same network. 2 checks since 5 February 2026, PFAS-4 always below the detection limit (4 ng/L). Source: Hub'eau, Qualité de l'eau potable (Ministère de la Santé / OFB / BRGM).
Details and sources
PFAS over time in Longpont
3 PFAS checks since 14 February 2025, from the published measurements. Samples from 2 communes on the same network: it's the same water, so each one applies to Longpont.
“Calculated”: PFAS-4 worked out from the four substances in the same sample. The chart, averages and trends use lab-published sums only.
| Date | PFAS-4 | Sum of 20 PFAS | Sampled at |
|---|---|---|---|
| < 4 ng/L | < 29 ng/L | Villers-Hélon | |
| < 4 ng/L | < 29 ng/L | Chouy | |
| < 4 ng/L · calculated | < 100 ng/L | Chouy |
Calculated values: “<” is an upper bound from published thresholds, “≥” a lower bound, “–” means no published sum or complete measurement. How to read a PFAS result
What the latest check found
The authorities have not published an overall verdict for this water.
Values to watch
These results are close to their legal limit, or over it.
| What was tested | Value | Limit | Status |
|---|---|---|---|
| Nitrate | 39.1 mg/L | ≤ 50 mg/L | within the limit |
See all 13 test results
| What was tested | Value | Limit | Status |
|---|---|---|---|
| Nitrate | 39.1 mg/L | ≤ 50 mg/L | within the limit |
| Nitrite | <0,010 mg/L | ≤ 0.5 mg/L | within the limit |
| Copper | 0.1 mg(Cu)/L | ≤ 2 mg(Cu)/L | within the limit |
| Nickel | 0.7 µg/L | ≤ 20 µg/L | within the limit |
| Cadmium | <0,5 µg/L | ≤ 5 µg/L | within the limit |
| Chromium | <0,5 µg/L | ≤ 50 µg/L | within the limit |
| Escherichia coli | 0 n/(100mL) | ≤ 0 mL) | within the limit |
| Enterococci | 0 n/(100mL) | ≤ 0 mL) | within the limit |
| Coliform bacteria | 0 n/(100mL) | ≤ 0 mL) | within the limit |
| pH | 7.9 unité pH | 6.5–9 unité pH | within the limit |
| Electrical conductivity | 705 µS/cm | 200–1,100 µS/cm | within the limit |
| Iron | <5 µg/L | ≤ 200 µg/L | within the limit |
| Turbidity | <0,30 NFU | ≤ 2 NFU | within the limit |
Frequently asked questions
Is tap water in Longpont safe to drink?
All the values shown here (27 April 2026) are within the legal limits, but the authorities have not published an overall verdict for this water. “Eau d’alimentation non conforme aux limites de qualité en vigueur pour le paramètre plomb. Cette teneur en plomb n’est représentative que po ur le point d’utilisation d’eau concerné et non pour l’ensemble du rés eau de distribution. Un nouveau recontrôle sera réalisé.”
How high are PFAS levels in Longpont's drinking water?
At the latest check the total of 20 PFAS ("forever chemicals") was below the laboratory's reporting limit of 29 ng/L. The EU limit is 100 ng/L, so this water is under 29 % of the limit. (below the EU limit)
Does the water in Longpont also meet the strictest limits in Europe?
As far as this check can tell, yes. None of the four compounds was quantified, so their total is below 4 ng/L, the sum of the laboratory's detection limits, and under Sweden's legal limit of 4 ng/L in force since 2026.
Are PFAS levels rising in Longpont's tap water?
Too few quantified checks to say (0 since 14 February 2025). pfasnearme adds each new publication weekly; a trend needs at least three quantified values. These history statistics use laboratory-published sums only.
How hard is the water in Longpont?
No hardness value is available for Longpont in this source.
Where does this data come from?
All values come from official publications: Hub'eau, Qualité de l'eau potable (Ministère de la Santé / OFB / BRGM). Retrieved on 12 September 2026.
Same water network
Same distribution network as Longpont, so in principle the same water.
Nearby communes
The closest to Longpont on this site.
Data source
- Hub'eau, Qualité de l'eau potable (Ministère de la Santé / OFB / BRGM)
- https://hubeau.eaufrance.fr/api/v1/qualite_eau_potable/resultats_dis?code_commune=02438
- License
- Licence Ouverte / Open Licence (Etalab)
- Retrieved
- 12 September 2026
- Supply networks
- UDI DU NADON
This site is a data project, not an official source. If in doubt, check with your water supplier or local authority.