PFAS in Rennes's tap water: under 3.4 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 3.4 ng/L, 6.8 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.
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 0.4 to 1 ng/L upward. None reached that limit, so their total is below 3.4 ng/L rather than zero.
checked on 6 May 2026
20 PFAS (see each substance)
| PFAS substance | Value |
|---|---|
| Acide perfluorobutanoïque (PFBA) | <0,0050 µg/L |
| Acide perfluoro-nonanoïque (PFNA) | <0,0010 µg/L |
| Acide perfluoroheptanoïque (PFHPA) | <0,0010 µg/L |
| Acide perfluorodecane sulfonique (PFDS) | <0,00040 µg/L |
| Acide perfluoro tridecane sulfonique (PFTrDS) | <0,00040 µg/L |
| Perfluorohexane sulfonate (PFHXS) | <0,00040 µg/L |
| Acide perfluorohexanoïque (PFHXA) | <0,0010 µg/L |
| Acide perfluoro undecanoïque (PFUnA) | <0,0010 µg/L |
| Acide sulfonique de perfluorobutane (PFBS) | <0,00040 µg/L |
| Acide perfluoropentane sulfonique (PFPS) | <0,00040 µg/L |
| Acide perfluorododécane sulfonique (PFDoDS) | <0,00040 µg/L |
| Acide perfluoro-octanoïque (PFOA) | <0,0010 µg/L |
| Acide perfluorododécanoique (PFDoDA) | <0,0010 µg/L |
| Acide perfluoropentanoïque (PFPEA) | <0,0050 µg/L |
| Acide perfluoro-decanoïque (PFDA) | <0,0010 µg/L |
| Acide sulfonique de perfluorooctane (PFOS) | <0,0010 µg/L |
| Acide perfluoro undecane sulfonique (PFUnDS) | <0,00040 µg/L |
| Acide perfluoro tridecanoique (PFTrDA) | <0,0010 µg/L |
| Acide perfluorononane sulfonique (PFNS) | <0,00040 µg/L |
| Acide perfluoroheptane sulfonique (PFHpS) | <0,00040 µg/L |
None found. The lab sees nothing below 3.4 ng/L, so our 0.5 ng/L benchmark cannot be checked.
Water report for Rennes
Get new PFAS results for Rennes, 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
- 6 May 2026
- Water supplier
- SPL EBR
In Rennes, none of the 4 most closely watched PFAS (PFAS-4) was detected at the latest PFAS check on 6 May 2026. The total is below 3.4 ng/L, the sum of the detection limits and 6.8 times our 0.5 ng/L benchmark. Sum of 20 PFAS: <SEUIL µg/L, below the EU legal limit (100 ng/L). 21 checks since 15 April 2025: PFAS-4 up to 11.93 ng/L, sometimes below the detection limit, averaging at least 0.36 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 Rennes
23 PFAS checks since 18 February 2025, from the published measurements. Samples from 5 communes on the same network: it's the same water, so each one applies to Rennes. Samples come from 3 distribution networks. The trend refers to the network “CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES”.
“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 | Network |
|---|---|---|---|---|
| < detection limit | < detection limit | Rennes | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| < detection limit | < detection limit | Vern-sur-Seiche | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| < detection limit | < detection limit | Rennes | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| < detection limit | < detection limit | Rennes | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| < detection limit | < detection limit | Rennes | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| 11.93 ng/L | 73.8 ng/L | Rennes | 035000446, 035000446 +1 | |
| 1.62 ng/L | 2.92 ng/L | Plouasne | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| 1.8 ng/L | 5.4 ng/L | Plouasne | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| 1.93 ng/L | 16.61 ng/L | Sixt-sur-Aff | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| < detection limit | < detection limit | Rennes | 035000446, 035000446 +1 | |
| 0.44 ng/L | 2.35 ng/L | Mézières-sur-Couesnon | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| < detection limit | < detection limit | Rennes | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES |
Show the 11 earlier checks (back to 18 February 2025)
| < detection limit | 7.8 ng/L | Plouasne | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| < detection limit | < detection limit | Mézières-sur-Couesnon | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| < detection limit | < detection limit | Rennes | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| < detection limit | < detection limit | Mézières-sur-Couesnon | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| < detection limit | < detection limit | Plouasne | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| < detection limit | < detection limit | Rennes | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| 0.47 ng/L | 1.19 ng/L | Mézières-sur-Couesnon | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| < detection limit | < detection limit | Plouasne | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| 2 ng/L | 2 ng/L | Rennes | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| 0.55 ng/L – < 3.55 ng/L · calculated | 2 ng/L | Sixt-sur-Aff | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES | |
| < 3.4 ng/L · calculated | < detection limit | Rennes | CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES |
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
At the latest check, the water was within every limit tested.
See all 21 test results
| What was tested | Value | Limit | Status |
|---|---|---|---|
| Nitrate | 24.8 mg/L | ≤ 50 mg/L | within the limit |
| Nitrite | <0,02 mg/L | ≤ 0.5 mg/L | within the limit |
| Lead | <1,0 µg/L | ≤ 10 µg/L | within the limit |
| Copper | 0.0035 mg(Cu)/L | ≤ 2 mg(Cu)/L | within the limit |
| Nickel | 2 µg/L | ≤ 20 µg/L | within the limit |
| Arsenic | <0,20 µg/L | ≤ 10 µg/L | within the limit |
| Cadmium | <0,025 µg/L | ≤ 5 µg/L | within the limit |
| Chromium | <1,0 µg/L | ≤ 50 µg/L | within the limit |
| Uranium | <0,50 µg/L | ≤ 30 µg/L | within the limit |
| Fluoride | 0.073 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 unité pH | 6.5–9 unité pH | within the limit |
| Water hardness | 15.5 °f | no limit | for reference |
| Electrical conductivity | 418 µS/cm | 200–1,100 µS/cm | within the limit |
| Chloride | 44.9 mg/L | ≤ 250 mg/L | within the limit |
| Sulphate | 19.5 mg/L | ≤ 250 mg/L | within the limit |
| Sodium | 18 mg/L | ≤ 200 mg/L | within the limit |
| Iron | <20 µg/L | ≤ 200 µg/L | within the limit |
| Turbidity | <0,20 NFU | ≤ 2 NFU | within the limit |
Frequently asked questions
Is tap water in Rennes safe to drink?
Yes. At the check on 27 July 2026, the tap water in Rennes was within every limit tested. “Eau d'alimentation conforme aux exigences de qualité en vigueur pour l'ensemble des paramètres mesurés. A noter cependant en ce point d'éc hantillonnage, la présence d'une flore revivifiable anormalement élevé e. L'exploitant a été informé de cette situation dès connaissance de c elle-ci par mon service.”
How high are PFAS levels in Rennes's drinking water?
The total of 20 PFAS ("forever chemicals") was last measured at –. The EU limit is 100 ng/L, so this water is at – of the limit. (below the EU limit)
Does the water in Rennes 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 3.4 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 Rennes's tap water?
No clear trend. Since 18 February 2025, 21 checks have been published; on the main network the PFAS-4 sum ranged between 0.44 ng/L and 2 ng/L (6 quantified values), at times below the detection limit. pfasnearme only reports a trend from a change of at least 25 % and 1 ng/L. These history statistics use laboratory-published sums only.
How hard is the water in Rennes?
The water hardness in Rennes is 15.5 °f (medium). 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 21 September 2026.
Same water network
Same distribution network as Rennes, so in principle the same water.
Nearby communes
The closest to Rennes 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=35238
- License
- Licence Ouverte / Open Licence (Etalab)
- Retrieved
- 21 September 2026
- Supply networks
- CEBR_VILLEJEAN/ROPHEMEL/MEZIERES/AVA_RENNES
This site is a data project, not an official source. If in doubt, check with your water supplier or local authority.