Water hardness and tap water in Zirndorf
Landkreis Fürth, Bayern · Postcode 90513
This page is a translation of the German version; the German page is authoritative. German version · Report a translation error
- Limits of the Drinking Water OrdinancemetAll tested parameters (16), at the waterworks
- Water hardness21.4 °dH, hardNo legal limit, only a range
- Data coverageCore parameters: 1 of 7Score provisional
Verified drinking-water values: water “Versorgungsbereich Weitersdorf”
| Parameter | Value | Limit (TrinkwV) | Sampling date | Source | Status |
|---|---|---|---|---|---|
| Nitrate | 0.72 mg/L | 50 mg/L | 3 July 2025 | Stadtwerke Zirndorf GmbH | verified |
| Chloride | 29.8 mg/L | 250 mg/L | 3 July 2025 | Stadtwerke Zirndorf GmbH | verified |
| Sulphate | 39.9 mg/L | 250 mg/L | 3 July 2025 | Stadtwerke Zirndorf GmbH | verified |
| Sodium | 12.6 mg/L | 200 mg/L | 3 July 2025 | Stadtwerke Zirndorf GmbH | verified |
| Calcium | 81 mg/L | – | 3 July 2025 | Stadtwerke Zirndorf GmbH | verified |
| Magnesium | 43.7 mg/L | – | 3 July 2025 | Stadtwerke Zirndorf GmbH | verified |
| pH | 7.67 | 6.5–9.5 | 3 July 2025 | Stadtwerke Zirndorf GmbH | verified |
| Total hardness | 21.4 °dH (hard) | no legal limit | 3 July 2025 | Stadtwerke Zirndorf GmbH | verified |
| Electrical conductivity | 745 µS/cm | – | 3 July 2025 | Stadtwerke Zirndorf GmbH | verified |
| Fluoride | 0.64 mg/L | 1.5 mg/L | 3 July 2025 | Stadtwerke Zirndorf GmbH | verified |
| Iron | < 0.01 mg/L | 0.2 mg/L | 3 July 2025 | Stadtwerke Zirndorf GmbH | verified |
| Manganese | < 0.002 mg/L | 0.05 mg/L | 3 July 2025 | Stadtwerke Zirndorf GmbH | verified |
Note from the test report (in the German original): Blatt der Stadtwerke zur Probe vom 03.07.2025. Dieser Wert gilt für den Versorgungsbereich Turm Weitersdorf, zu dem alle Haushalte gehören, die nicht in den Straßenlisten für den Hochbehälter Alte Veste stehen. Blei, Kupfer, Uran und PFAS nennt das Blatt nicht. Die Website der Stadtwerke zeigt für Sulfat 39,3 mg/l, das PDF 39,9 mg/l; hier steht der Wert aus dem PDF.
Background on household plumbing, not a measurement: in Zirndorf, 31 % of buildings with living space were built before 1970, and a further 24 % between 1970 and 1979 (Zensus 2022, Statistisches Bundesamt, dl-de/by-2-0). (Zensus 2022) According to the German Environment Agency (Umweltbundesamt), lead pipes exist at most in houses built before 1973 – and by no means in all of them. Whether there are any in your house is known to the owner or a plumber. (UBA)
What the values mean for Zirndorf
- Nitrate 0.72 mg/L – about 1 % of the limit of 50 mg/L and in the unremarkable range. Boiling does not reduce nitrate.
- pH 7.67 – within the range of the Drinking Water Ordinance (6.5 to 9.5). The pH determines how corrosive the water is in household plumbing.
Water hardness in Zirndorf in everyday life
At 21.4 °dH, Zirndorf is in the hardness range “hard” (soft: below 8.4 °dH, medium: 8.4–14 °dH, hard: above 14 °dH).
- Dose detergent for the hardness range “hard” – a larger amount is needed; a water softener for the washing machine can save detergent.
- Limescale builds up quickly: descale the kettle about every two to three weeks, and taps and shower heads too.
- In your own house, limescale protection or a water softener can be worthwhile at this hardness; in a rented flat, the owner decides.
Baby food and low sodium: tap water in Zirndorf next to the bottled-water thresholds
Bottled water may only be labelled “suitable for preparing infant food” („geeignet für die Zubereitung von Säuglingsnahrung“) if it keeps to the maximum levels of the German Mineral and Table Water Ordinance (Mineral- und Tafelwasser-Verordnung, Annex 6). Here the published values for Zirndorf are shown next to them, each substance on its own. This is a comparison with labelling thresholds for bottled water, not a statement on whether your tap water is suitable for baby food. (Min/TafelWV, Anlage 6)
For context: the German Environment Agency (Umweltbundesamt) considers preparing baby food with bottled water carrying this label necessary only in rare cases, for example when tap water is temporarily allowed to contain more than 50 mg/l nitrate. (UBA 2016, p. 59) Water from lead pipes in the house is always unsuitable for infants. (UBA 2020, p. 16) The values apply at the waterworks.
| Substance | Maximum level | Value in Zirndorf |
|---|---|---|
| Sodium | 20 mg/l | 12.6 mg/l – not above |
| Nitrate | 10 mg/l | 0.72 mg/l – not above |
| Nitrite | 0.02 mg/l | not in the report |
| Sulphate | 240 mg/l | 39.9 mg/l – not above |
| Fluoride | 0.7 mg/l | 0.64 mg/l – not above |
| Manganese | 0.05 mg/l | below the detection limit (0.002 mg/l) – not above |
| Arsenic | 0.005 mg/l | not in the report |
| Uranium | 0.002 mg/l | not in the report |
Against the other thresholds of Annex 6, the water would qualify as: low in sodium (“suitable for a low-sodium diet”) (Sodium 12.6 mg/l, threshold below 20 mg/l).
Questions about baby food are answered by your midwife, your paediatrician and the health office (Gesundheitsamt).
Frequently asked questions about tap water in Zirndorf
Can you drink the tap water in Zirndorf?
According to the verified values, yes: All tested parameters with a legal limit (16) meet the limits set by the German Drinking Water Ordinance (TrinkwV). WaterScore (provisional): 98.3 out of 100 – the test report contains only 1 of 7 core parameters. This applies to the water from the waterworks – restrictions can only arise from old household plumbing.
How hard is the water in Zirndorf?
It depends on the address: Versorgungsbereich Weitersdorf 21.4 °dH and Versorgungsbereich Alte Veste 16.5 °dH – both in the hardness range “hard”. Dose detergent for the hardness range “hard” – a larger amount is needed; a water softener for the washing machine can save detergent.
Is there PFAS in the tap water in Zirndorf?
The published analysis by Stadtwerke Zirndorf that we evaluated gives no PFAS value. This does not mean there is no PFAS in the water; there is simply no figure for it. Since 12 January 2026, a limit of 0.1 µg/l has applied to the sum of PFAS-20. The supplier can tell you whether PFAS was measured and with what result. For the other waters, the analyses give no PFAS value.
Do I need to filter my tap water in Zirndorf?
Based on the verified supplier values, a filter is not necessary. It can make sense if you do not like the taste. If you suspect lead pipes in an old building, a filter does not help; a laboratory analysis at the tap does – that is a question of the household plumbing, not of the water leaving the works.
WaterScore
- Total (provisional)98.3 / 100
- Chemical safety100 / 100
- Nutrients100 / 100
- General parameters100 / 100
- Data timeliness93.3 / 100
- Data quality100 / 100
Data coverage: 1 of 7 core parameters. Not in the test report: Nitrite, Lead, Copper, Arsenic, Uranium and PFAS (sum). Missing parameters are neither estimated nor counted as harmless: the score is based only on the values available and is therefore provisional. It is not a health assessment and says nothing about the water beyond the service connection. Methodology v4: how we calculate the WaterScore.
Evidence: cite and check
- Wasseranalyse, Probenahme 03.07.2025, Prüfbericht vom 15.07.2025 (Stadtwerke Zirndorf GmbH) · SHA-256 of the evaluated file: 1d52ed4cad8e4ae2…, checked on 1 November 2026
Suggested citation: Trinkwassermonitor (2025): Tap water in Zirndorf. Values according to the water supplier’s test report, sampling date 3 July 2025; at the waterworks, not household plumbing. https://trinkwassermonitor.ink/en/tap-water/zirndorf/
JSON: /api/v1/evidence?city=zirndorf
Data as of: 3 July 2025 · verified: 12 of 12 evaluated parameters. (older than twelve months – under § 46 TrinkwV your supplier must publish current values online)
This page shows only verified test data with sources, or states explicitly where data is missing (no estimated values). Cite as: “Trinkwassermonitor (2026). Tap water in Zirndorf. Retrieved from https://trinkwassermonitor.ink/en/tap-water/zirndorf/.”