Water hardness in Castelnau-le-Lez
32 °fH very hard
Tap water in Castelnau-le-Lez is very hard: 32 °fH (320 mg/L · 18.7 gpg · 17.9 °dH).
Source: Ministère de la Santé (ARS), contrôle sanitaire SISE-Eaux, commune 34057 (2026-08) · data checked 2026-10-19
Range across supply zones: 317–324 mg/L.
Castelnau-le-Lez (Hérault) is served by Veolia (S.A. Ruas Michel). The ARS health control (SISE-Eaux, commune 34057, August 2026) measures 320 mg/L CaCO₃, between 317 and 324 mg/L. The water is classed as very hard.
TH en °fH : douce < 15, moyennement dure 15–25, dure 25–35, très dure > 35 °fH (classes usuelles ARS).
Water data
| Total hardness | 32 °fH |
|---|---|
| Utility | S.A. Ruas Michel Groupe Veolia |
How Castelnau-le-Lez compares
- Tap water in Castelnau-le-Lez is 34 % harder than the median of the 33641 cities we track in France (23.9 °fH).
- By hardness it ranks 5629 of 33641 in France (1 = hardest); 83 % of these cities have softer water.
- In Hérault it is number 91 of 324 cities; the regional median is 25.7 °fH.
- Nearest city with clearly softer water: Lattes, 7 km away (19.9 °fH).
- Nearest city with clearly harder water: Clapiers, 3 km away (49 °fH).
Ranking of the hardest and softest water in France →
What it means at home
- Severe scale: heater elements and washing-machine heaters fail early.
- Detergent use is very high; taps and screens coat within days.
- Dishwasher at maximum salt setting.
- An ion-exchange softener is practically essential; RO for drinking water.
How much salt will you use for softening?
Yes. At this hardness a softener pays for itself through appliance life and detergent.
Descale a coffee machine or kettle about every 1 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Castelnau-le-Lez
| Brand | Setting for this water |
|---|---|
| Bosch | H05 |
| Miele | 18 °dH |
| AEG / Electrolux | 4 |
| Beko | 5th |
| Hoover | S3 |
| LG | H3 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is Castelnau-le-Lez water hard or soft?
It is very hard: 320 mg/L as CaCO₃ (18.7 gpg, 17.9 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Castelnau-le-Lez safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. TH en °fH : douce < 15, moyennement dure 15–25, dure 25–35, très dure > 35 °fH (classes usuelles ARS).
How many grains per gallon is Castelnau-le-Lez water?
18.7 gpg, equal to 17.9 °dH, 32 °fH or 320 mg/L calcium carbonate.
What dishwasher salt setting should I use in Castelnau-le-Lez?
For 320 mg/L (17.9 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Castelnau-le-Lez?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Ministère de la Santé (ARS), contrôle sanitaire SISE-Eaux, commune 34057 (2026-08). Method: own measurement. Ministère de la Santé (ARS), contrôle sanitaire SISE-Eaux, commune 34057 · Outdated figure? Tell us