PFAS in Saint-Malo-de-Guersac's tap water: under 3 ng/L, none of the four main PFAS detected
Last PFAS check: · Source: Hub'eau
PFAS in drinking water
None of the 4 most harmful PFAS detected
The lab sees nothing below 3 ng/L, 6 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 Nantes, on the same distribution network as Saint-Malo-de-Guersac (SAINT-NAZAIRE AGGLO - LA CARENE). 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 0.5 to 1.5 ng/L upward. None reached that limit, so their total is below 3 ng/L rather than zero.
checked on 7 July 2026
20 PFAS (see each substance)
| PFAS substance | Value |
|---|---|
| Acide perfluoropentanoïque (PFPEA) | 0.005 µg/L |
| Acide perfluorobutanoïque (PFBA) | 0.0042 µg/L |
| Acide perfluorohexanoïque (PFHXA) | 0.0023 µg/L |
| Acide perfluoroheptane sulfonique (PFHpS) | <0,001 µg/L |
| Acide perfluorononane sulfonique (PFNS) | <0,001 µg/L |
| Acide perfluoro-nonanoïque (PFNA) | <0,0005 µg/L |
| Acide perfluoro-octanoïque (PFOA) | <0,0005 µg/L |
| Acide perfluoro tridecane sulfonique (PFTrDS) | <0,005 µg/L |
| Acide perfluoro undecane sulfonique (PFUnDS) | <0,0015 µg/L |
| Acide perfluorododécanoique (PFDoDA) | <0,0015 µg/L |
| Acide sulfonique de perfluorooctane (PFOS) | <0,0015 µg/L |
| Acide perfluoro tridecanoique (PFTrDA) | <0,001 µg/L |
| Acide perfluorodecane sulfonique (PFDS) | <0,001 µg/L |
| Acide perfluoropentane sulfonique (PFPS) | <0,001 µg/L |
| Acide sulfonique de perfluorobutane (PFBS) | <0,001 µg/L |
| Acide perfluoro undecanoïque (PFUnA) | <0,0015 µg/L |
| Acide perfluorododécane sulfonique (PFDoDS) | <0,0015 µg/L |
| Acide perfluoroheptanoïque (PFHPA) | <0,001 µg/L |
| Acide perfluoro-decanoïque (PFDA) | <0,0015 µg/L |
| Perfluorohexane sulfonate (PFHXS) | <0,0005 µg/L |
None found. The lab sees nothing below 3 ng/L, so our 0.5 ng/L benchmark cannot be checked.
Water report for Saint-Malo-de-Guersac
Get new PFAS results for Saint-Malo-de-Guersac, with a short explanation. At most one update a week, only when there's something new.
- EU legal limit
- 12 ng/L sum of 20 PFAS, below the 100 ng/L limit
- Last PFAS test
- 7 July 2026
- Water supplier
- SAINT-NAZAIRE AGGLO - LA CARENE
In Saint-Malo-de-Guersac, none of the 4 most closely watched PFAS (PFAS-4) was detected at the latest PFAS check on 7 July 2026. The total is below 3 ng/L, the sum of the detection limits and 6 times our 0.5 ng/L benchmark. Sum of 20 PFAS: 12 ng/L (0.012 µg/L), below the EU legal limit (100 ng/L). Sampled in Nantes, on the same network. 9 checks since 10 February 2025: PFAS-4 up to 5.1 ng/L, sometimes below the detection limit, averaging at least 1.34 ng/L over 12 months (non-detects as 0). Rising on the main network. Source: Hub'eau, Qualité de l'eau potable (Ministère de la Santé / OFB / BRGM).
Details and sources
PFAS over time in Saint-Malo-de-Guersac
23 PFAS checks since 23 January 2025, from the published measurements. Samples from 3 communes on the same network: it's the same water, so each one applies to Saint-Malo-de-Guersac.
“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 |
|---|---|---|---|
| < 3 ng/L · calculated | 12 ng/L | Nantes | |
| < 3 ng/L · calculated | 8.9 ng/L | Nantes | |
| < 3 ng/L · calculated | 8.9 ng/L | Nantes | |
| < 3 ng/L · calculated | < detection limit | Campbon | |
| < 3 ng/L · calculated | 4.9 ng/L | Nantes | |
| < 3 ng/L · calculated | 3.2 ng/L | Nantes | |
| 0.6 ng/L – < 3.1 ng/L · calculated | 6.6 ng/L | Nantes | |
| < 3 ng/L · calculated | 0.6 ng/L | Campbon | |
| < 3 ng/L · calculated | 1.1 ng/L | Nantes | |
| 4.5 ng/L | 24 ng/L | Férel | |
| 5.1 ng/L | 32 ng/L | Férel | |
| 2.5 ng/L | 18 ng/L | Férel |
Show the 11 earlier checks (back to 23 January 2025)
| 2.4 ng/L – < 3.9 ng/L · calculated | 3.2 ng/L | Campbon | |
| < 10 ng/L · calculated | < detection limit | Nantes | |
| < 10 ng/L · calculated | < detection limit | Nantes | |
| < detection limit | < detection limit | Férel | |
| < detection limit | < detection limit | Férel | |
| < detection limit | < detection limit | Férel | |
| < detection limit | < detection limit | Férel | |
| < detection limit | < detection limit | Férel | |
| < detection limit | < detection limit | Férel | |
| < 10 ng/L · calculated | < detection limit | Campbon | |
| < 10 ng/L · calculated | < detection limit | Nantes |
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.
See all 17 test results
| What was tested | Value | Limit | Status |
|---|---|---|---|
| Nitrate | 7.6 mg/L | ≤ 50 mg/L | within the limit |
| Nitrite | <0,010 mg/L | ≤ 0.5 mg/L | within the limit |
| Lead | <0,2 µg/L | ≤ 10 µg/L | within the limit |
| Copper | 0.0119 mg(Cu)/L | ≤ 2 mg(Cu)/L | within the limit |
| Nickel | 3.4 µg/L | ≤ 20 µg/L | within the limit |
| Cadmium | <0,010 µg/L | ≤ 5 µg/L | within the limit |
| Chromium | 0.4 µg/L | ≤ 50 µg/L | within the limit |
| Escherichia coli | <1 n/(100mL) | ≤ 0 mL) | within the limit |
| Enterococci | <1 n/(100mL) | ≤ 0 mL) | within the limit |
| Coliform bacteria | <1 n/(100mL) | ≤ 0 mL) | within the limit |
| pH | 7.7 unité pH | 6.5–9 unité pH | within the limit |
| Water hardness | 32.2 °f | no limit | for reference |
| Electrical conductivity | 723 µS/cm | 200–1,100 µS/cm | within the limit |
| Chloride | 53.9 mg/L | ≤ 250 mg/L | within the limit |
| Sulphate | 95.1 mg/L | ≤ 250 mg/L | within the limit |
| Iron | 2 µg/L | ≤ 200 µg/L | within the limit |
| Turbidity | <0,30 NFU | ≤ 2 NFU | within the limit |
Frequently asked questions
Is tap water in Saint-Malo-de-Guersac safe to drink?
All the values shown here (7 July 2026) are within the legal limits, but the authorities have not published an overall verdict for this water. “Eau d'alimentation conforme aux exigences de qualité en vigueur pour l'ensemble des paramètres mesurés.”
How high are PFAS levels in Saint-Malo-de-Guersac's drinking water?
The total of 20 PFAS ("forever chemicals") was last measured at 12 ng/L. The EU limit is 100 ng/L, so this water is at 12 % of the limit. (below the EU limit)
Does the water in Saint-Malo-de-Guersac 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 3 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 Saint-Malo-de-Guersac's tap water?
Yes. On the main network, the PFAS-4 sum rose from 2.5 ng/L (28 August 2025) to 4.5 ng/L (25 November 2025) across 3 quantified checks. pfasnearme's benchmark is 0.5 ng/L as an annual mean. These history statistics use laboratory-published sums only.
How hard is the water in Saint-Malo-de-Guersac?
The water hardness in Saint-Malo-de-Guersac is 32.2 °f (hard). 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.
Same water network
Same distribution network as Saint-Malo-de-Guersac, so in principle the same water.
Nearby communes
The closest to Saint-Malo-de-Guersac 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=44176
- License
- Licence Ouverte / Open Licence (Etalab)
- Retrieved
- 28 September 2026
- Supply networks
- SAINT-NAZAIRE AGGLO - LA CARENE
This site is a data project, not an official source. If in doubt, check with your water supplier or local authority.