Drinking water quality in Cergy
PFAS in drinking water
The total of 20 PFAS ("forever chemicals") was last measured at 0.002 µg/L. The EU limit is 0.1 µg/L, so this water is at 2 % of the limit. (3 February 2026)
The four most harmful PFAS add up to 0 µg/L, below the health limit of 0.004 µg/L used in Sweden since 2026.
Substances too small to measure count as 0, so the real total may be higher.
12 PFAS (see each substance)
| Acide perfluoropentanoïque (PFPEA) | 0.002 µg/L |
| Acide perfluorododécanoique (PFDoDA) | <0,001 µg/L |
| Acide perfluorononane sulfonique (PFNS) | <0,002 µg/L |
| Acide perfluoro-octanoïque (PFOA) | <0,0010 µg/L |
| Acide perfluoro undecanoïque (PFUnA) | <0,001 µg/L |
| Acide perfluoro-nonanoïque (PFNA) | <0,001 µg/L |
| Acide sulfonique de perfluorooctane (PFOS) | <0,001 µg/L |
| Acide perfluoroheptanoïque (PFHPA) | <0,001 µg/L |
| Acide perfluoroheptane sulfonique (PFHpS) | <0,002 µg/L |
| Acide perfluorobutanoïque (PFBA) | <0,002 µg/L |
| Acide perfluoro undecane sulfonique (PFUnDS) | <0,002 µg/L |
| Acide perfluorodecane sulfonique (PFDS) | <0,001 µg/L |
Water report for Cergy
Get the free water report for Cergy, plus an alert whenever new official results are published.
Official assessment
The latest official test passed all quality requirements.
„A noter, la présence d'une flore aerobie à 36°C élevée malgré la prése nce de chlore. Eau conforme aux exigences de qualité en vigueur pour l'ensemble des a utres paramètres mesurés.“
Values to watch
These values are at least halfway to their legal limit, or over it.
| Parameter | Value | Limit | Status |
|---|---|---|---|
| Lead | 12 µg/L | ≤ 10 µg/L | exceeded |
Show all 20 official measurements
| Parameter | Value | Limit | Status |
|---|---|---|---|
| Nitrate | 24.2 mg/L | ≤ 50 mg/L | within limit |
| Nitrite | <0,01 mg/L | ≤ 0.5 mg/L | within limit |
| Lead | 12 µg/L | ≤ 10 µg/L | exceeded |
| Copper | 0.222 mg(Cu)/L | ≤ 2 mg(Cu)/L | within limit |
| Nickel | 8 µg/L | ≤ 20 µg/L | within limit |
| Arsenic | <2 µg/L | ≤ 10 µg/L | within limit |
| Cadmium | <1 µg/L | ≤ 5 µg/L | within limit |
| Chromium | <5,00 µg/L | ≤ 50 µg/L | within limit |
| Uranium | <10 µg/L | ≤ 30 µg/L | within limit |
| Fluoride | 0.11 mg/L | ≤ 1.5 mg/L | within limit |
| Escherichia coli | 0 n/(100mL) | ≤ 0 mL) | within limit |
| Enterococci | 0 n/(100mL) | ≤ 0 mL) | within limit |
| Coliform bacteria | 0 n/(100mL) | ≤ 0 mL) | within limit |
| pH | 7.4 unité pH | 6.5–9 unité pH | within limit |
| Water hardness | 29.38 °f | no limit | informational |
| Electrical conductivity | 637 µS/cm | 200–1,100 µS/cm | within limit |
| Chloride | 31.1 mg/L | ≤ 250 mg/L | within limit |
| Sulphate | 46.9 mg/L | ≤ 250 mg/L | within limit |
| Iron | <10 µg/L | ≤ 200 µg/L | within limit |
| Turbidity | 0.17 NFU | ≤ 2 NFU | within limit |
Frequently asked questions
Is tap water in Cergy safe to drink?
Yes. The latest official test (16 April 2026) checked the tap water in Cergy and it passed every requirement.
How high are PFAS levels in Cergy's drinking water?
The total of 20 PFAS ("forever chemicals") was last measured at 0.002 µg/L. The EU limit is 0.1 µg/L, so this water is at 2 % of the limit. (below the EU limit)
Does the water in Cergy also meet the strictest limits in Europe?
Yes. Even against Europe's strictest limit, the health limit of 0.004 µg/L used in Sweden since 2026, the measured value of 0 µg/L stays below.
How hard is the water in Cergy?
The water hardness in Cergy is 29.38 °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 28 August 2026.
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=95127
- License
- Licence Ouverte / Open Licence (Etalab)
- Retrieved
- 28 August 2026
- Supply networks
- CACP OUEST, CACP CERGY-ST CHRIST PUISEUX PONTOISE, CACP NORD, CACP PREFECTURE VILLAGES, CERGY VILLAGE-VAUREAL VILLAGE, MENUCOURT COURDIM CERGY LE HT, COM. D'AGGLOMERATION CENTRE, COM. D'AGGLOMERATION BOUCLE NORD
This site is a data project, not an official source. If in doubt, check with your water supplier or local authority.