PFAS in Guenroc's tap water: 3.4 ng/L, 6.8x our 0.5 ng/L benchmark
Last PFAS check: · Source: Hub'eau
PFAS in drinking water
6.8× above our health benchmark
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.
More about this result
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 90% of the cities we track
checked on 5 June 2026
20 PFAS (see each substance)
| PFAS substance | Value |
|---|---|
| Acide sulfonique de perfluorooctane (PFOS) | 0.0034 µg/L |
| Acide perfluoroheptanoïque (PFHPA) | <0,005 µg/L |
| Acide perfluoro tridecanoique (PFTrDA) | <0,002 µg/L |
| Acide perfluoro tridecane sulfonique (PFTrDS) | <0,001 µg/L |
| Acide perfluoro-nonanoïque (PFNA) | <0,001 µg/L |
| Acide perfluorododécane sulfonique (PFDoDS) | <0,001 µg/L |
| Acide perfluoroheptane sulfonique (PFHpS) | <0,002 µg/L |
| Acide sulfonique de perfluorobutane (PFBS) | <0,005 µg/L |
| Acide perfluoro undecane sulfonique (PFUnDS) | <0,001 µg/L |
| Acide perfluoro-octanoïque (PFOA) | <0,002 µg/L |
| Acide perfluoropentane sulfonique (PFPS) | <0,001 µg/L |
| Acide perfluoro-decanoïque (PFDA) | <0,002 µg/L |
| Acide perfluoropentanoïque (PFPEA) | <0,002 µg/L |
| Perfluorohexane sulfonate (PFHXS) | <0,002 µg/L |
| Acide perfluorobutanoïque (PFBA) | <0,005 µg/L |
| Acide perfluorodecane sulfonique (PFDS) | <0,001 µg/L |
| Acide perfluorononane sulfonique (PFNS) | <0,001 µg/L |
| Acide perfluorododécanoique (PFDoDA) | <0,002 µg/L |
| Acide perfluoro undecanoïque (PFUnA) | <0,002 µg/L |
| Acide perfluorohexanoïque (PFHXA) | <0,005 µg/L |
Above our health benchmark. Here are some filter options.
- EU legal limit
- 3.4 ng/L sum of 20 PFAS, below the 100 ng/L limit
- Last PFAS test
- 5 June 2026
- Water supplier
- S.T.G.S.
In Guenroc, the 4 most closely watched PFAS (PFAS-4) add up to 3.4 ng/L (0.0034 µg/L) at the latest PFAS check on 5 June 2026. That's 6.8 times our 0.5 ng/L health benchmark, but below Sweden's legal limit of 4 ng/L. Sum of 20 PFAS: 3.4 ng/L (0.0034 µg/L), below the EU legal limit (100 ng/L). 7 checks since 6 February 2025: PFAS-4 up to 3.8 ng/L, sometimes below the detection limit, averaging at least 2.2 ng/L over 12 months (non-detects as 0). No clear trend. Source: Hub'eau, Qualité de l'eau potable (Ministère de la Santé / OFB / BRGM).
Details and sources
PFAS over time in Guenroc
7 PFAS checks since 6 February 2025, values as published. Samples from 3 communes on the same network: it's the same water, so each one applies to Guenroc.
| Date | PFAS-4 | Sum of 20 PFAS | Sampled at |
|---|---|---|---|
| 3.4 ng/L | 3.4 ng/L | Guenroc | |
| 1.6 ng/L | 1.6 ng/L | Saint-Juvat | |
| < detection limit | < detection limit | Val-d'Arguenon | |
| 3.8 ng/L | 14.2 ng/L | Val-d'Arguenon | |
| < detection limit | < detection limit | Val-d'Arguenon | |
| < detection limit | < detection limit | Val-d'Arguenon | |
| < detection limit | < detection limit | Val-d'Arguenon |
“<” 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
At the latest check, the water was within every limit tested.
Values to watch
These results are close to their legal limit, or over it.
| What was tested | Value | Limit | Status |
|---|---|---|---|
| Nitrate | 26 mg/L | ≤ 50 mg/L | within the limit |
See all 18 test results
| What was tested | Value | Limit | Status |
|---|---|---|---|
| Nitrate | 26 mg/L | ≤ 50 mg/L | within the limit |
| Nitrite | <0,01 mg/L | ≤ 0.5 mg/L | within the limit |
| Arsenic | <0,5 µg/L | ≤ 10 µg/L | within the limit |
| Cadmium | <0,025 µg/L | ≤ 5 µg/L | within the limit |
| Chromium | <0,5 µg/L | ≤ 50 µg/L | within the limit |
| Uranium | <0,5 µg/L | ≤ 30 µg/L | within the limit |
| Fluoride | 0.099 mg/L | ≤ 1.5 mg/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 | 8.14 unité pH | 6.5–9.5 pH | within the limit |
| Water hardness | 13 °f | no limit | for reference |
| Electrical conductivity | 416 µS/cm | 200–1,100 µS/cm | within the limit |
| Chloride | 66 mg/L | ≤ 250 mg/L | within the limit |
| Sulphate | 22 mg/L | ≤ 250 mg/L | within the limit |
| Sodium | 23 mg/L | ≤ 200 mg/L | within the limit |
| Iron | <2,5 µg/L | ≤ 200 µg/L | within the limit |
| Turbidity | 0.13 NFU | ≤ 2 NFU | within the limit |
Frequently asked questions
Is tap water in Guenroc safe to drink?
Yes. At the check on 5 June 2026, the tap water in Guenroc was within every limit tested. “Eau d'alimentation conforme aux exigences de qualité en vigueur pour l'ensemble des paramètres mesurés. Cependant, les analyses réalisées ont mis en évidence la présence notable de chlorates. La valeur la plus faible possible de ce paramètre doit être visée sans pour autant compromettre la désinfection. La réglementation fixe une limite de qualité à 700 µg/l lorsqu'une méthode de désinfection des eaux destinées à la consommation humaine qui génère des chlorates est utilisée. Au delà de cette valeur, il est recommandé de ne pas consommer cette eau, une restriction d'usage est nécessaire. La présence de chlorates peut avoir pour origine la présence d'impuretés dans le désinfectant employé (javel, hypochlorite de calcium ...), dans ce cas la limite de qualité est fixée à 250 µg/l. Il convient, pour respecter cette exigence, de veiller à la pureté des réactifs employés ainsi qu'à leur condition de stockage et d'emploi (dosage, utilisation sous 3 mois après la livraison). Compte tenu de la teneur mesurée en chlorates sur ce prélèvement, un suivi renforcé sera mis en place sur ce paramètre.”
How high are PFAS levels in Guenroc's drinking water?
The total of 20 PFAS ("forever chemicals") was last measured at 3.4 ng/L. The EU limit is 100 ng/L, so this water is at 3 % of the limit. (below the EU limit)
Does the water in Guenroc 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 3.4 ng/L stays below.
Are PFAS levels rising in Guenroc's tap water?
No clear trend. Since 6 February 2025, 7 checks have been published; on the main network the PFAS-4 sum ranged between 1.6 ng/L and 3.8 ng/L (3 quantified values), at times below the detection limit. pfasnearme only reports a trend from a change of at least 25 % and 1 ng/L.
How hard is the water in Guenroc?
The water hardness in Guenroc is 13 °f (soft). This mainly matters for household appliances and detergent dosing, not for health.
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 28 September 2026.
Nearby communes
The closest to Guenroc 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=22069
- License
- Licence Ouverte / Open Licence (Etalab)
- Retrieved
- 28 September 2026
- Supply networks
- GUENROC
Water report for Guenroc
Get new PFAS results for Guenroc, with a short explanation. At most one update a week, only when there's something new.
This site is a data project, not an official source. If in doubt, check with your water supplier or local authority.