PFAS in Les Houches's tap water: 1 ng/L, 2x our 0.5 ng/L benchmark
Last PFAS check: · Source: Hub'eau
PFAS in drinking water
2× 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 82% of the cities we track
checked on 11 February 2026
20 PFAS (see each substance)
| PFAS substance | Value |
|---|---|
| Acide sulfonique de perfluorooctane (PFOS) | 0.001 µg/L |
| Acide perfluoroheptane sulfonique (PFHpS) | <0,002 µg/L |
| Acide perfluoro undecanoïque (PFUnA) | <0,001 µg/L |
| Acide perfluoro tridecanoique (PFTrDA) | <0,001 µg/L |
| Acide perfluorododécane sulfonique (PFDoDS) | <0,001 µg/L |
| Acide perfluoro-octanoïque (PFOA) | <0,001 µg/L |
| Acide perfluoro-nonanoïque (PFNA) | <0,001 µg/L |
| Acide perfluoro undecane sulfonique (PFUnDS) | <0,002 µg/L |
| Acide perfluoroheptanoïque (PFHPA) | <0,001 µg/L |
| Acide perfluoropentane sulfonique (PFPS) | <0,001 µg/L |
| Acide perfluorobutanoïque (PFBA) | <0,002 µg/L |
| Acide perfluorononane sulfonique (PFNS) | <0,002 µg/L |
| Acide perfluoropentanoïque (PFPEA) | <0,001 µg/L |
| Acide sulfonique de perfluorobutane (PFBS) | <0,001 µg/L |
| Acide perfluoro tridecane sulfonique (PFTrDS) | <0,005 µg/L |
| Acide perfluorododécanoique (PFDoDA) | <0,001 µg/L |
| Acide perfluorodecane sulfonique (PFDS) | <0,001 µg/L |
| Acide perfluoro-decanoïque (PFDA) | <0,001 µg/L |
| Perfluorohexane sulfonate (PFHXS) | <0,001 µg/L |
| Acide perfluorohexanoïque (PFHXA) | <0,002 µg/L |
Above our health benchmark. Here are some filter options.
- EU legal limit
- 1 ng/L sum of 20 PFAS, below the 100 ng/L limit
- Last PFAS test
- 11 February 2026
- Water supplier
- REGIE DE L'EAU O2VCMB
In Les Houches, the 4 most closely watched PFAS (PFAS-4) add up to 1 ng/L (0.001 µg/L) at the latest PFAS check on 11 February 2026. That's 2 times our 0.5 ng/L health benchmark, but below Sweden's legal limit of 4 ng/L. Sum of 20 PFAS: 1 ng/L (0.001 µg/L), below the EU legal limit (100 ng/L). 5 checks since 6 October 2025: PFAS-4 up to 1 ng/L, sometimes below the detection limit. Source: Hub'eau, Qualité de l'eau potable (Ministère de la Santé / OFB / BRGM).
Details and sources
PFAS over time in Les Houches
6 PFAS checks since 10 April 2025, from the published measurements. Samples from 2 communes on the same network: it's the same water, so each one applies to Les Houches. Samples come from 4 distribution networks. The trend refers to the network “LES HOUCHES - RESEAU PRINCIPAL”.
“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 |
|---|---|---|---|---|
| 1 ng/L | 1 ng/L | Les Houches | LES HOUCHES - RESEAU PRINCIPAL | |
| < 4 ng/L | < 29 ng/L | Servoz | SERVOZ - RESEAU PRINCIPAL | |
| < 4 ng/L | < 29 ng/L | Les Houches | LES HOUCHES - RESEAU PRINCIPAL | |
| < 4 ng/L | < 29 ng/L | Les Houches | LES HOUCHES - LES CHAVANTS | |
| < 4 ng/L | < 29 ng/L | Les Houches | LES HOUCHES - LE THOVEX | |
| < 4 ng/L · calculated | < 100 ng/L | Les Houches | LES HOUCHES - RESEAU PRINCIPAL |
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.
Values to watch
These results are close to their legal limit, or over it.
Outside a reference value: Electrical conductivity 154 µS/cm on 15 April 2026 (reference 200–1,100 µS/cm). These are indicator parameters with reference values, not legal limits.
| What was tested | Value | Limit | Status |
|---|---|---|---|
| Electrical conductivity | 154 µS/cm | 200–1,100 µS/cm | below the reference value |
See all 20 test results
| What was tested | Value | Limit | Status |
|---|---|---|---|
| Nitrate | 4.9 mg/L | ≤ 50 mg/L | within the limit |
| Nitrite | <0,01 mg/L | ≤ 0.5 mg/L | within the limit |
| Lead | <0,20 µg/L | ≤ 10 µg/L | within the limit |
| Copper | 0.0021 mg/L | ≤ 2 mg/L | within the limit |
| Arsenic | <3,0 µg/L | ≤ 10 µg/L | within the limit |
| Cadmium | <0,10 µg/L | ≤ 5 µg/L | within the limit |
| Chromium | <0,50 µg/L | ≤ 50 µg/L | within the limit |
| Uranium | 1.4 µg/L | ≤ 30 µg/L | within the limit |
| Fluoride | <0,05 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 | 7.8 unité pH | 6.5–9 unité pH | within the limit |
| Water hardness | 7.5 °f | no limit | for reference |
| Electrical conductivity | 154 µS/cm | 200–1,100 µS/cm | below the reference value |
| Chloride | 0.18 mg/L | ≤ 250 mg/L | within the limit |
| Sulphate | 15 mg/L | ≤ 250 mg/L | within the limit |
| Sodium | 1.7 mg/L | ≤ 200 mg/L | within the limit |
| Iron | <10 µg/L | ≤ 200 µg/L | within the limit |
| Turbidity | <0,20 NFU | ≤ 2 NFU | within the limit |
Frequently asked questions
Is tap water in Les Houches safe to drink?
Yes. At the check on 15 April 2026, the tap water in Les Houches was within every limit tested. Outside a reference value: Electrical conductivity 154 µS/cm on 15 April 2026 (reference 200–1,100 µS/cm). These are indicator parameters with reference values, not legal limits. “Eau d'alimentation conforme aux limites de qualité et non conforme aux références de qualité.”
How high are PFAS levels in Les Houches's drinking water?
The total of 20 PFAS ("forever chemicals") was last measured at 1 ng/L. The EU limit is 100 ng/L, so this water is at 1 % of the limit. (below the EU limit)
Does the water in Les Houches 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 1 ng/L stays below.
Are PFAS levels rising in Les Houches's tap water?
Too few quantified checks to say (1 since 10 April 2025). pfasnearme adds each new publication weekly; a trend needs at least three quantified values. These history statistics use laboratory-published sums only.
How hard is the water in Les Houches?
The water hardness in Les Houches is 7.5 °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 12 September 2026.
Same water network
Same distribution network as Les Houches, so in principle the same water.
Nearby communes
The closest to Les Houches 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=74143
- License
- Licence Ouverte / Open Licence (Etalab)
- Retrieved
- 12 September 2026
- Supply networks
- SERVOZ - RESEAU PRINCIPAL, LES HOUCHES - RESEAU PRINCIPAL, LES HOUCHES - COUPEAU, LES HOUCHES - LE THOVEX, LES HOUCHES - VAUDAGNE, LES HOUCHES - LE LAC, LES HOUCHES - LES CHAVANTS
Water report for Les Houches
Get new PFAS results for Les Houches, 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.