PFAS in the tap water of Cernay (Haut-Rhin): 50 ng/L, 100x our 0.5 ng/L benchmark
Last PFAS check: · Source: Hub'eau
PFAS in drinking water
100× 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.
Sample taken in Steinbach, on the same distribution network as Cernay (CERNAY-WATTWILLER ZH-STEINBACH). 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.
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 100% of the cities we track
checked on 24 June 2026
20 PFAS (see each substance)
| PFAS substance | Value |
|---|---|
| Acide sulfonique de perfluorooctane (PFOS) | 0.03 µg/L |
| Perfluorohexane sulfonate (PFHXS) | 0.014 µg/L |
| Acide perfluorohexanoïque (PFHXA) | 0.01 µg/L |
| Acide perfluoropentanoïque (PFPEA) | 0.006 µg/L |
| Acide perfluoro-octanoïque (PFOA) | 0.006 µg/L |
| Acide sulfonique de perfluorobutane (PFBS) | 0.004 µg/L |
| Acide perfluoroheptanoïque (PFHPA) | 0.004 µg/L |
| Acide perfluoropentane sulfonique (PFPS) | 0.002 µg/L |
| Acide perfluoro-decanoïque (PFDA) | <0,002 µg/L |
| Acide perfluoro tridecanoique (PFTrDA) | <0,002 µg/L |
| Acide perfluorododécane sulfonique (PFDoDS) | <0,002 µg/L |
| Acide perfluorododécanoique (PFDoDA) | <0,002 µg/L |
| Acide perfluorobutanoïque (PFBA) | <0,005 µg/L |
| Acide perfluoro tridecane sulfonique (PFTrDS) | <0,005 µg/L |
| Acide perfluoroheptane sulfonique (PFHpS) | <0,002 µg/L |
| Acide perfluoro-nonanoïque (PFNA) | <0,002 µg/L |
| Acide perfluorodecane sulfonique (PFDS) | <0,002 µg/L |
| Acide perfluoro undecane sulfonique (PFUnDS) | <0,002 µg/L |
| Acide perfluorononane sulfonique (PFNS) | <0,002 µg/L |
| Acide perfluoro undecanoïque (PFUnA) | <0,002 µg/L |
Above our health benchmark. Here are some filter options.
- EU legal limit
- 76 ng/L sum of 20 PFAS, below the 100 ng/L limit
- Last PFAS test
- 24 June 2026
- Water supplier
- COM. DE COM.THANN-CERNAY SEC CERNAY
In Cernay, the 4 most closely watched PFAS (PFAS-4) add up to 50 ng/L (0.05 µg/L) at the latest PFAS check on 24 June 2026. That's 100 times our 0.5 ng/L health benchmark, and above Sweden's legal limit of 4 ng/L. Sum of 20 PFAS: 76 ng/L (0.076 µg/L), below the EU legal limit (100 ng/L). Sampled in Steinbach, on the same network. 2 checks since 8 April 2025: sum of 20 PFAS from 13 ng/L to 76 ng/L. Source: Hub'eau, Qualité de l'eau potable (Ministère de la Santé / OFB / BRGM).
Details and sources
PFAS over time in Cernay
2 PFAS checks since 8 April 2025, from the published measurements. Samples from 2 communes on the same network: it's the same water, so each one applies to Cernay.
“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 |
|---|---|---|---|
| 50 ng/L – < 52 ng/L · calculated | 76 ng/L | Steinbach | |
| 13 ng/L – < 15 ng/L · calculated | 13 ng/L | Cernay |
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 20 test results
| What was tested | Value | Limit | Status |
|---|---|---|---|
| Nitrate | 9.2 mg/L | ≤ 50 mg/L | within the limit |
| Nitrite | <0,01 mg/L | ≤ 0.5 mg/L | within the limit |
| Lead | <2 µg/L | ≤ 10 µg/L | within the limit |
| Copper | 0.028 mg(Cu)/L | ≤ 2 mg(Cu)/L | within the limit |
| Nickel | <5 µg/L | ≤ 20 µg/L | within the limit |
| Arsenic | 0.43 µg/L | ≤ 10 µg/L | within the limit |
| Cadmium | <0,01 µg/L | ≤ 5 µg/L | within the limit |
| Chromium | 0.24 µg/L | ≤ 50 µg/L | within the limit |
| Fluoride | 0.06 mg/L | ≤ 1.5 mg/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 unité pH | 6.5–9 unité pH | within the limit |
| Water hardness | 9.6 °f | no limit | for reference |
| Electrical conductivity | 310 µS/cm | 200–1,100 µS/cm | within the limit |
| Chloride | 33 mg/L | ≤ 250 mg/L | within the limit |
| Sulphate | 21 mg/L | ≤ 250 mg/L | within the limit |
| Sodium | 20 mg/L | ≤ 200 mg/L | within the limit |
| Iron | 15 µg/L | ≤ 200 µg/L | within the limit |
| Turbidity | <0,1 NFU | ≤ 2 NFU | within the limit |
Frequently asked questions
Is tap water in Cernay safe to drink?
Yes. At the check on 30 July 2026, the tap water in Cernay was within every limit tested. “Eau d'alimentation conforme aux exigences de qualité en vigueur pour l'ensemble des paramètres mesurés.”
How high are PFAS levels in Cernay's drinking water?
The total of 20 PFAS ("forever chemicals") was last measured at 76 ng/L. The EU limit is 100 ng/L, so this water is at 76 % of the limit. (below the EU limit)
Does the water in Cernay also meet the strictest limits in Europe?
No. The four most harmful PFAS add up to 50 ng/L. That is 12.5 times Sweden's legal limit of 4 ng/L, in force since 2026. Germany will set a similar one in 2028. The water still passes the current EU legal limit (100 ng/L for the total of 20 PFAS).
Are PFAS levels rising in Cernay's tap water?
Calculated PFAS-4 values are listed in the table. The chart uses laboratory-published sum-of-20 results; there are too few laboratory-published PFAS-4 sums for the existing trend calculation.
How hard is the water in Cernay?
The water hardness in Cernay is 9.6 °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 21 September 2026.
Same water network
Same distribution network as Cernay, so in principle the same water.
Nearby communes
The closest to Cernay 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=68063
- License
- Licence Ouverte / Open Licence (Etalab)
- Retrieved
- 21 September 2026
- Supply networks
- CERNAY-WATTWILLER ZH-STEINBACH
Water report for Cernay
Get new PFAS results for Cernay, 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.