Drinking water in Olten
2 supply zones — values can differ depending on the district. Below is the zone with the most documented parameters, the others collapsed underneath. To determine the exact match, look up the postcode.
How to read the share of the parametric value
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.
4600, Messegelände 1 - Welser Messe
eww agAssigned via the water supplier — the exact supply zone boundary within the postcode is not yet linked.
These values are more than a year old. The most recent analysis the water supplier has published for this zone dates from 12/01/2024. We have no newer values — which is why we show the latest available ones rather than none at all. They say nothing about how the water has changed since then.
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Nitrate | 8,9 mg/l | 50 mg/l | 18 % | Single value · 4600, Messegelände 1 - Welser Messe |
| Sulphate | 6,3 mg/l | 250 mg/l | 3 % | Single value · 4600, Messegelände 1 - Welser Messe |
| Sodium | 4,8 mg/l | 200 mg/l | 2 % | Single value · 4600, Messegelände 1 - Welser Messe |
Show all recorded parameters (11 — most recent value per parameter)
Chemical parameters (1)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Nitrate | 8,9 mg/l | 50 mg/l | 18 % | Single value · 4600, Messegelände 1 - Welser Messe |
Indicator parameters (5)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Chloride | 6,8 mg/l | 200 mg/l | 3 % | Single value · 4600, Messegelände 1 - Welser Messe |
| Conductivity (25 °C) | 349 µS/cm | 2,500 µS/cm | — | Single value · 4600, Messegelände 1 - Welser Messe |
| pH | 7,7 | 6,5–9,5 | — | Single value · 4600, Messegelände 1 - Welser Messe |
| Sodium | 4,8 mg/l | 200 mg/l | 2 % | Single value · 4600, Messegelände 1 - Welser Messe |
| Sulphate | 6,3 mg/l | 250 mg/l | 3 % | Single value · 4600, Messegelände 1 - Welser Messe |
Further parameters (5)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Calcium | 61,1 mg/l | 400 mg/l | 15 % | Single value · 4600, Messegelände 1 - Welser Messe |
| Carbonate hardness | 10,3 °dH | — | — | Single value · 4600, Messegelände 1 - Welser Messe |
| Magnesium | 13,4 mg/l | 150 mg/l | 9 % | Single value · 4600, Messegelände 1 - Welser Messe |
| Potassium | 1 mg/l | 50 mg/l | 2 % | Single value · 4600, Messegelände 1 - Welser Messe |
| Total hardness | 11,6 °dH | — | — | Single value · 4600, Messegelände 1 - Welser Messe |
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.
Postcodes in this zone: 4600
Show 1 more supply zone
Olten - Trimbach
Städtische Betriebe OltenAssigned via the water supplier — the exact supply zone boundary within the postcode is not yet linked.
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Nitrate | 25.2 mg/l | 40 mg/l | 63 % | Mean · Olten - Trimbach |
| Escherichia coli (E. coli) | nn not detectable Unit not stated in the document | 0/100 ml | — | Maximum · Median nn · Olten - Trimbach |
Show all recorded parameters (9 — most recent value per parameter)
Microbiology (3)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Aerobic mesophilic bacteria | nn not detectable Unit not stated in the document | 300 1/ml | — | Mean · Olten - Trimbach |
| Escherichia coli (E. coli) | nn not detectable Unit not stated in the document | 0/100 ml | — | Maximum · Median nn · Olten - Trimbach |
| Intestinal enterococci | nn not detectable Unit not stated in the document | 0/100 ml | — | Maximum · Median nn · Olten - Trimbach |
Chemical parameters (1)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Nitrate | 25.2 mg/l | 40 mg/l | 63 % | Mean · Olten - Trimbach |
Metabolites (2)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Chlorothalonil metabolite R417888 | 0.05 µg/l | 0.1 µg/l | 50 % | Mean · Olten - Trimbach |
| Chlorothalonil metabolite R471811 | 0.36 µg/l | 0.1 µg/l | 360 % Mean above the parametric value | Mean · Olten - Trimbach |
Annual means and medians are not individual measured values, but the parametric values apply per sample. If a mean lies above it, at least one individual sample was above it — the mean does not say how many, or by how much. That is why this is not reported here as an exceedance of the parametric value. What counts remains the water supplier's publication, which each row links to.
Further parameters (3)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Calcium | 116 mg/l | — | — | Mean · Olten - Trimbach |
| Magnesium | 7.01 mg/l | — | — | Mean · Olten - Trimbach |
| Total hardness | 31 °fH | — | — | Mean · Olten - Trimbach |
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.
Postcodes in this zone: 4600
Frequently asked questions about drinking water in Olten
- How hard is the water in Olten?
- eww ag publishes a total hardness of 11.6 °dH for the supply zone 4600, Messegelände 1 - Welser Messe (hardness range medium). 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: 2024-01-12, retrieved on 08/08/2026.
- How much nitrate is in the drinking water in Olten?
- eww ag publishes a nitrate value of 8,9 mg/l for the supply zone 4600, Messegelände 1 - Welser Messe. The statutory parametric value is 50 mg/l; the measured value represents 18 % of the parametric value. Basis: 2024-01-12, retrieved on 08/08/2026.
- Who supplies the drinking water in Olten?
- eww ag. The values shown here come from the supply zone 4600, Messegelände 1 - Welser Messe 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.