Drinking water in Solothurn
One supply zone, water supplier: Regio Energie Solothurn.
How to read the share of the parametric value
12 % Share of the parametric value. The proportion of the permitted maximum that the measured value uses — here 12 %, so just over an eighth.
< 10 % * Below the limit of quantification. The substance was not detectable. The mark shows where the detection limit lies relative to the parametric value — the actual share of the parametric value is below that.
Several samples per year: for chemical parameters the mean value is given, for microbiological ones the highest measured value. There the parametric value is zero — a single finding would disappear in the average, and it is precisely that finding which is the information. Which reference applies is stated in the last column of the table.
Stadt Solothurn
Regio Energie SolothurnAssigned via the water supplier — the exact supply zone boundary within the postcode is not yet linked.
Water hardness
14.3 °dH
Hardness range hard
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Nitrate | 13.6 mg/l | 40 mg/l | 34 % | Mean · Stadt Solothurn |
| Escherichia coli (E. coli) | 0 KBE/100ml | 0/100 ml | — | Maximum · Median 0 · Stadt Solothurn |
| Sulphate | 12.48 mg/l | — | — | Mean · Stadt Solothurn |
| Sodium | 10.3 mg/l | 200 mg/l | 5 % | Mean · Stadt Solothurn |
Show all recorded parameters (22 — most recent value per parameter)
Microbiology (3)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Aerobic mesophilic bacteria | 2 KBE/ml | 300 1/ml | — | Mean · Stadt Solothurn |
| Escherichia coli (E. coli) | 0 KBE/100ml | 0/100 ml | — | Maximum · Median 0 · Stadt Solothurn |
| Intestinal enterococci | 0 KBE/100ml | 0/100 ml | — | Maximum · Median 0 · Stadt Solothurn |
Chemical parameters (2)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Fluoride | 0.07 mg/l | 1.5 mg/l | 5 % | Mean · Stadt Solothurn |
| Nitrate | 13.6 mg/l | 40 mg/l | 34 % | Mean · Stadt Solothurn |
PFAS (1)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Perfluorooctanesulfonic acid (PFOS) | 0.011 µg/l | 0.3 µg/l | 4 % | Mean · Stadt Solothurn |
Metabolites (2)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Chlorothalonil metabolite R417888 | 0.02 µg/l | 0.1 µg/l | 20 % | Mean · Stadt Solothurn |
| Chlorothalonil metabolite R471811 | 0.08 µg/l | 0.1 µg/l | 80 % | Mean · Stadt Solothurn |
Indicator parameters (8)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Chloride | 13.53 mg/l | — | — | Mean · Stadt Solothurn |
| Conductivity (25 °C) | 520 µS/cm | — | — | Mean · Stadt Solothurn |
| Iron | 0.005 mg/l | 0.2 mg/l | 3 % | Mean · Stadt Solothurn |
| pH | 7.44 | — | — | Mean · Stadt Solothurn |
| Sodium | 10.3 mg/l | 200 mg/l | 5 % | Mean · Stadt Solothurn |
| Sulphate | 12.48 mg/l | — | — | Mean · Stadt Solothurn |
| Temperature | 12.83 °C | — | — | Mean · Stadt Solothurn |
| Turbidity | 0.17 TE/F | — | — | Mean · Stadt Solothurn |
Further parameters (6)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Calcium | 87.6 mg/l | — | — | Mean · Stadt Solothurn |
| Dissolved organic carbon (DOC) | 0.42 mg/l | — | — | Mean · Stadt Solothurn |
| Hydrogen carbonate | 316.3 mg/l | — | — | Mean · Stadt Solothurn |
| Magnesium | 8.9 mg/l | — | — | Mean · Stadt Solothurn |
| Potassium | 1.7 mg/l | — | — | Mean · Stadt Solothurn |
| Total hardness | 25.5 °fH | — | — | Mean · Stadt Solothurn |
Values taken unchanged from the publications linked below — for each parameter the most recent recorded value. „—" in the parametric value column: no currently valid legal parametric value is stored in our database for this parameter; the parameter register with all parametric values is being expanded continuously.
Source: https://trinkwasser.ch/de/versorger/853/regio-energie-solothurn/2572/stadt-solothurn · 2025 · 2025 · retrieved on 07/08/2026
Postcodes in this zone: 4500
Frequently asked questions about drinking water in Solothurn
- How hard is the water in Solothurn?
- Regio Energie Solothurn publishes a total hardness of 25.5 °fH for the supply zone Stadt Solothurn — that corresponds to 14.3 °dH. The hardness range is a classification under the German Detergents and Cleaning Products Act (soft below 8,4 °dH, medium 8,4 to 14 °dH, hard above that) and not a quality verdict — it indicates how much calcium and magnesium is dissolved in the water. Basis: 2025, retrieved on 07/08/2026.
- How much nitrate is in the drinking water in Solothurn?
- Regio Energie Solothurn publishes a nitrate value of 13.6 mg/l for the supply zone Stadt Solothurn. The statutory parametric value is 40 mg/l; the measured value represents 34 % of the parametric value. Basis: 2025, retrieved on 07/08/2026.
- Who supplies the drinking water in Solothurn?
- Regio Energie Solothurn. The values shown here come from the supply zone Stadt Solothurn and apply to the water the supplier delivers. What happens between the building connection and the tap — in old lead pipes, for example — is not covered by these analyses; information on that is provided by owners, the health authority or an examination by an accredited laboratory.
General questions — how current the data is, limit of quantification, parametric values, who is behind this site — are answered under Questions & answers.