How hard is the water in Rottenschwil?

Wasserversorgung Rottenschwil publishes a total hardness of 33.3 °fH for the supply zone Rottenschwil — that corresponds to 18.6 °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 Rottenschwil?

Wasserversorgung Rottenschwil publishes a nitrate value of 28.5 mg/l for the supply zone Rottenschwil. The statutory parametric value is 40 mg/l; the measured value represents 71 % of the parametric value. Basis: 2025, retrieved on 07/08/2026.

Who supplies the drinking water in Rottenschwil?

Wasserversorgung Rottenschwil. The values shown here come from the supply zone Rottenschwil 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.

Drinking water in Rottenschwil

One supply zone, water supplier: Wasserversorgung Rottenschwil.

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.

Rottenschwil

Wasserversorgung Rottenschwil

Assigned via the water supplier — the exact supply zone boundary within the postcode is not yet linked.

Water hardness

18.6 °dH

Hardness range hard

Key values Rottenschwil
Parameter	Value	Parametric value	Share of the parametric value	Reference
Nitrate	28.5 mg/l	40 mg/l	71 %	Mean · Rottenschwil
Sulphate	15 mg/l	—	—	Mean · Rottenschwil
Sodium	5.7 mg/l	200 mg/l	3 %	Mean · Rottenschwil

Show all recorded parameters (10 — most recent value per parameter)

Chemical parameters (1)

Chemical parameters – Rottenschwil
Parameter	Value	Parametric value	Share of the parametric value	Reference
Nitrate	28.5 mg/l	40 mg/l	71 %	Mean · Rottenschwil

Metabolites (2)

Metabolites – Rottenschwil
Parameter	Value	Parametric value	Share of the parametric value	Reference
Chlorothalonil metabolite R417888	0.145 µg/l	0.1 µg/l	145 % Mean above the parametric value	Mean · Rottenschwil
Chlorothalonil metabolite R471811	1.55 µg/l	0.1 µg/l	1,550 % Mean above the parametric value	Mean · Rottenschwil

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.

Indicator parameters (3)

Indicator parameters – Rottenschwil
Parameter	Value	Parametric value	Share of the parametric value	Reference
Chloride	14.1 mg/l	—	—	Mean · Rottenschwil
Sodium	5.7 mg/l	200 mg/l	3 %	Mean · Rottenschwil
Sulphate	15 mg/l	—	—	Mean · Rottenschwil

Further parameters (4)

Further parameters – Rottenschwil
Parameter	Value	Parametric value	Share of the parametric value	Reference
Calcium	97 mg/l	—	—	Mean · Rottenschwil
Magnesium	21.8 mg/l	—	—	Mean · Rottenschwil
Potassium	1 mg/l	—	—	Mean · Rottenschwil
Total hardness	33.3 °fH	—	—	Mean · Rottenschwil

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/1323/wasserversorgung-rottenschwil/3253/rottenschwil · 2025 · 2025 · retrieved on 07/08/2026

Postcodes in this zone: 8919

Frequently asked questions about drinking water in Rottenschwil

How hard is the water in Rottenschwil?: Wasserversorgung Rottenschwil publishes a total hardness of 33.3 °fH for the supply zone Rottenschwil — that corresponds to 18.6 °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 Rottenschwil?: Wasserversorgung Rottenschwil publishes a nitrate value of 28.5 mg/l for the supply zone Rottenschwil. The statutory parametric value is 40 mg/l; the measured value represents 71 % of the parametric value. Basis: 2025, retrieved on 07/08/2026.
Who supplies the drinking water in Rottenschwil?: Wasserversorgung Rottenschwil. The values shown here come from the supply zone Rottenschwil 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.