Hardness, nitrates, pH, sanitary compliance: the real tap water quality in Dolus-d'Oléron (hard water), with official Hub'Eau data updated monthly.
⚠ Non-compliance detectedTap water in Dolus-d'Oléron has a hardness of 31.3°f — a high level that accelerates scale build-up on surfaces and appliances. Within a few weeks without maintenance, deposits become visible on taps, shower walls and heating elements (washing machine, kettle, water heater). Monthly descaling and regular use of antiscale products are recommended to protect your installations. Official sanitary tests report a non-compliance on at least one monitored parameter: see the details below.
Results from the latest official sanitary samples (Hub’Eau, French Ministry of Health). Click a card to understand what each parameter measures.
Sanitary compliance summarises adherence to French regulatory limits across all analysed parameters (bacteriology, chemistry, radioactivity). Compliant water can be consumed directly from the tap without additional treatment.
The TH (titre hydrotimétrique) measures calcium and magnesium concentration, expressed in French degrees (°f). The higher it is, the harder the water and the faster limescale deposits on surfaces and in appliances.
Nitrates come mainly from agriculture and waste water. The French regulatory limit is 50 mg/L; below 25 mg/L, the level is considered low.
PFAS are persistent chemical compounds, sometimes called "forever chemicals", used in industry. The vigilance threshold used here is 0.1 µg/L, consistent with current health recommendations.
pH measures water acidity. Regulations require a value between 6.5 and 9: outside this range, water may encourage pipe corrosion or affect taste.
Free chlorine is added to disinfect water and prevent bacterial growth in the distribution network. High levels can produce a perceptible taste or odour, without health risk at authorised levels.
Turbidity measures water clarity, in NTU (nephelometric turbidity units). A low value indicates clear water with few suspended particles.
Conductivity reflects overall water mineralisation, in µS/cm. It has no strict sanitary threshold but indicates the dissolved mineral salt content.
Maintenance budget: ~£88/year
For 2 persons, water at 31.3°f deposits around 1.5 kg of limescale per year in your appliances. Estimated cost in descalers, salt and filters.
Calcium: ~50 mg per litre
Your water provides 50 mg of calcium/L, which is 5% of the recommended daily intake.
Filter jug: cartridge every 4 months
At 31.3°f, replace the cartridge every 4 months. An under-sink filter lasts 6 to 12 months.
Drinking water in Dolus-d'Oléron, in the Charente-Maritime department is managed by r.e.s.e., which handles production, treatment and distribution of tap water in the municipality. The last available official sanitary analysis for Dolus-d'Oléron dates from 9 June 2026.
Compare the water quality in Dolus-d'Oléron with any other city available on the site.
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How does Dolus-d'Oléron compare to the 65 cities in the Charente-Maritime department and the 4806 largest cities in France in our database, on key water quality indicators.
Comparison based on 65 cities in Charente-Maritime department and the 4806 largest cities in France in our database.
Top 10 cities in the Charente-Maritime department ranked by tap water quality in our database.
Dolus-d'Oléron ranks 62th out of 65 cities in the department in our database.
Tap water in Dolus-d'Oléron has a quality index of 3.6/10 (caution recommended) in our database, calculated on nitrates, PFAS, pH, free chlorine and turbidity. This is a comparative reading of Hub'Eau data, not an official rating.
Tap water hardness in Dolus-d'Oléron is 31.3°f (French degrees), making it hard water. The average is 28.7°f in the Charente-Maritime department and 22.1°f across our entire database.
Yes. At 31.3°f, water in Dolus-d'Oléron is hard: limescale deposits quickly on taps, shower walls and heating appliances.
It may be justified. At 31.3°f, water in Dolus-d'Oléron is hard: a softener limits scale build-up in pipes and heating appliances, worth comparing with simple antiscale maintenance depending on daily inconvenience.
The last available official sanitary analysis (9 June 2026) reports a non-compliance on at least one parameter. Official conclusion: "Eau d'alimentation non-conforme aux exigences de qualité." The affected parameter and any usage restrictions are in the official report: contact your water distributor or regional health agency (ARS) for details.
The pH measured in Dolus-d'Oléron is 7.3. Regulations require a value between 6.5 and 9: the water is within this range.
Compare tap water quality in other cities of the Charente-Maritime department, ranked by quality index.
Methodology: the quality index compares each city against the 4806 other cities in our database on 5 parameters (nitrates, PFAS, pH, free chlorine, turbidity) and averages its relative position on each. This is not an official rating, only a simplified comparative reading of Hub’Eau data.