Water hardness in Concarneau
12 °fH hard
Tap water in Concarneau is hard: 12 °fH (120 mg/L · 7 gpg · 6.7 °dH).
Source: Ministère de la Santé (ARS), contrôle sanitaire SISE-Eaux, commune 29039 (2026-08) · data checked 2026-10-19
Concarneau is supplied by Concarneau Cornouaille Agglomération in Finistère, where water comes mostly from rivers and reservoirs on granite bedrock. These rocks release little limestone, yet the water is hard: 120 mg/L CaCO₃. Scale is modest but present.
TH en °fH : douce < 15, moyennement dure 15–25, dure 25–35, très dure > 35 °fH (classes usuelles ARS).
Water data
| Total hardness | 12 °fH |
|---|---|
| Utility | Ca Concarneau Cornouaille Agglomeration |
How Concarneau compares
- Tap water in Concarneau is 50 % softer than the median of the 33641 cities we track in France (23.9 °fH).
- By hardness it ranks 27030 of 33641 in France (1 = hardest); 19 % of these cities have softer water.
- In Finistère it is number 133 of 269 cities; the regional median is 12 °fH.
- Nearest city with clearly softer water: Trégunc, 5 km away (8.4 °fH).
- Nearest city with clearly harder water: Pleuven, 10 km away (16 °fH).
Ranking of the hardest and softest water in France →
What it means at home
- Fast scale on taps, shower screens and kettle; white spots on glassware.
- Water heater: efficiency loss and element failures within years if unprotected.
- Dry skin and dull hair after showering are common.
- Softener recommended; jug or reverse osmosis for drinking.
How much salt will you use for softening?
Recommended, especially with a heater or boiler: scale cuts efficiency and shortens its life.
Descale a coffee machine or kettle about every 2 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Concarneau
| Brand | Setting for this water |
|---|---|
| Bosch | H01 |
| Miele | 7 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| Hoover | S1 |
| LG | H1 |
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 Concarneau water hard or soft?
It is hard: 120 mg/L as CaCO₃ (7 gpg, 6.7 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Concarneau 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 Concarneau water?
7 gpg, equal to 6.7 °dH, 12 °fH or 120 mg/L calcium carbonate.
What dishwasher salt setting should I use in Concarneau?
For 120 mg/L (6.7 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Concarneau?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: Ministère de la Santé (ARS), contrôle sanitaire SISE-Eaux, commune 29039 (2026-08). Method: own measurement. Ministère de la Santé (ARS), contrôle sanitaire SISE-Eaux, commune 29039 · Outdated figure? Tell us