How hard is the water in Winterthur?

Stadtwerk Winterthur publishes a total hardness of 27.1 °fH for the supply zone Winterthur: Tössgrundwasser — that corresponds to 15.2 °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 Winterthur?

Stadtwerk Winterthur publishes a nitrate value of 6.4 mg/l for the supply zone Winterthur: Tössgrundwasser. The statutory parametric value is 40 mg/l; the measured value represents 16 % of the parametric value. Basis: 2025, retrieved on 07/08/2026.

Who supplies the drinking water in Winterthur?

Stadtwerk Winterthur. The values shown here come from the supply zone Winterthur: Tössgrundwasser 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 Winterthur

One supply zone, water supplier: Stadtwerk Winterthur.

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.

Winterthur: Tössgrundwasser

Stadtwerk Winterthur

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

Water hardness

15.2 °dH

Hardness range hard

Key values Winterthur: Tössgrundwasser
Parameter	Value	Parametric value	Share of the parametric value	Reference
Sum of PFAS	< 0.027 µg/l below limit of quantification	—	—	Mean · Winterthur: Tössgrundwasser
Nitrate	6.4 mg/l	40 mg/l	16 %	Mean · Winterthur: Tössgrundwasser
Escherichia coli (E. coli)	0 KBE/100ml	0/100 ml	—	Maximum · Median 0 · Winterthur: Tössgrundwasser
Sulphate	4.1 mg/l	—	—	Mean · Winterthur: Tössgrundwasser
Sodium	5.8 mg/l	200 mg/l	3 %	Mean · Winterthur: Tössgrundwasser

Show all recorded parameters (26 — most recent value per parameter)

Microbiology (3)

Microbiology – Winterthur: Tössgrundwasser
Parameter	Value	Parametric value	Share of the parametric value	Reference
Aerobic mesophilic bacteria	5.1 KBE/ml	300 1/ml	—	Mean · Winterthur: Tössgrundwasser
Escherichia coli (E. coli)	0 KBE/100ml	0/100 ml	—	Maximum · Median 0 · Winterthur: Tössgrundwasser
Intestinal enterococci	0 KBE/100ml	0/100 ml	—	Maximum · Median 0 · Winterthur: Tössgrundwasser

Chemical parameters (2)

Chemical parameters – Winterthur: Tössgrundwasser
Parameter	Value	Parametric value	Share of the parametric value	Reference
Fluoride	0.066 mg/l	1.5 mg/l	4 %	Mean · Winterthur: Tössgrundwasser
Nitrate	6.4 mg/l	40 mg/l	16 %	Mean · Winterthur: Tössgrundwasser

PFAS (4)

PFAS – Winterthur: Tössgrundwasser
Parameter	Value	Parametric value	Share of the parametric value	Reference
Perfluorohexane sulfonic acid (PFHxS)	< 0.001 µg/l below limit of quantification	0.3 µg/l	< 0.3 % *	Mean · Winterthur: Tössgrundwasser
Perfluorooctanesulfonic acid (PFOS)	< 0.001 µg/l below limit of quantification	0.3 µg/l	< 0.3 % *	Mean · Winterthur: Tössgrundwasser
Perfluorooctanoic acid (PFOA)	< 0.0003 µg/l below limit of quantification	0.5 µg/l	< < 0.1 % *	Mean · Winterthur: Tössgrundwasser
Sum of PFAS	< 0.027 µg/l below limit of quantification	—	—	Mean · Winterthur: Tössgrundwasser

* Value below the limit of quantification: the actual share of the parametric value is not known; it lies somewhere below the stated upper bound. The marker shows where the limit of quantification of the measurement lies relative to the parametric value.

Metabolites (2)

Metabolites – Winterthur: Tössgrundwasser
Parameter	Value	Parametric value	Share of the parametric value	Reference
Chlorothalonil metabolite R417888	< 0.01 µg/l below limit of quantification	0.1 µg/l	< 10 % *	Mean · Winterthur: Tössgrundwasser
Chlorothalonil metabolite R471811	< 0.02 µg/l below limit of quantification	0.1 µg/l	< 20 % *	Mean · Winterthur: Tössgrundwasser

Indicator parameters (8)

Indicator parameters – Winterthur: Tössgrundwasser
Parameter	Value	Parametric value	Share of the parametric value	Reference
Chloride	7.8 mg/l	—	—	Mean · Winterthur: Tössgrundwasser
Conductivity (25 °C)	476 µS/cm	—	—	Mean · Winterthur: Tössgrundwasser
Iron	0.0065 mg/l	0.2 mg/l	3 %	Mean · Winterthur: Tössgrundwasser
Manganese	< 0.0005 mg/l below limit of quantification	50 µg/l	< 1 % *	Mean · Winterthur: Tössgrundwasser
pH	7.5	—	—	Mean · Winterthur: Tössgrundwasser
Sodium	5.8 mg/l	200 mg/l	3 %	Mean · Winterthur: Tössgrundwasser
Sulphate	4.1 mg/l	—	—	Mean · Winterthur: Tössgrundwasser
Temperature	12.9 °C	—	—	Mean · Winterthur: Tössgrundwasser

Further parameters (7)

Further parameters – Winterthur: Tössgrundwasser
Parameter	Value	Parametric value	Share of the parametric value	Reference
Calcium	75.8 mg/l	—	—	Mean · Winterthur: Tössgrundwasser
Dissolved organic carbon (DOC)	0.52 mg/l	—	—	Mean · Winterthur: Tössgrundwasser
Hydrogen carbonate	326 mg/l	—	—	Mean · Winterthur: Tössgrundwasser
Magnesium	19.8 mg/l	—	—	Mean · Winterthur: Tössgrundwasser
Potassium	1.4 mg/l	—	—	Mean · Winterthur: Tössgrundwasser
Spectral absorption coefficient 254 nm (SAC 254)	1.04 1/m	—	—	Mean · Winterthur: Tössgrundwasser
Total hardness	27.1 °fH	—	—	Mean · Winterthur: Tössgrundwasser

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/792/stadtwerk-winterthur/3438/winterthur-tossgrundwasser · 2025 · 2025 · retrieved on 07/08/2026

Postcodes in this zone: 8400 , 8409

Frequently asked questions about drinking water in Winterthur

How hard is the water in Winterthur?: Stadtwerk Winterthur publishes a total hardness of 27.1 °fH for the supply zone Winterthur: Tössgrundwasser — that corresponds to 15.2 °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 Winterthur?: Stadtwerk Winterthur publishes a nitrate value of 6.4 mg/l for the supply zone Winterthur: Tössgrundwasser. The statutory parametric value is 40 mg/l; the measured value represents 16 % of the parametric value. Basis: 2025, retrieved on 07/08/2026.
Who supplies the drinking water in Winterthur?: Stadtwerk Winterthur. The values shown here come from the supply zone Winterthur: Tössgrundwasser 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.

No data yet

For 3 postcodes 8405, 8406, 8408 there is no verified assignment yet.