Water hardness and tap water in Singen (Hohentwiel)
Landkreis Konstanz, Baden-Württemberg · Postcode 78224
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 (8), at the waterworks
- Water hardness20.2 °dH, hardNo legal limit, only a range
- Data coverageCore parameters: 1 of 7Score provisional
Verified drinking-water values
Note from the test report (in the German original): Eurofins-Prüfbericht für die Stadtwerke, Probe vom 24.02.2025 am Hochbehälter Hohentwiel, der zusammen mit dem Hochbehälter Buchberg die Kernstadt versorgt. Die Werte gelten für die Kernstadt, das Wasser dort ist teils mit Ozon aufbereitet. Die Stadtwerke nennen je Ort (Stand 03/2025): Kernstadt Nitrat 18 mg/l und 20,2 °dH, Hausen und Schlatt 27 mg/l und 19,6 °dH, Friedingen 16 mg/l und 20,2 °dH, Beuren 18 mg/l und 19,3 °dH, Bohlingen und Überlingen 19 mg/l und 21,3 °dH. Dieser Auszug enthält weder Schwermetalle noch PFAS. Die Werte gelten ab Hochbehälter.
Background on household plumbing, not a measurement: in Singen (Hohentwiel), 53 % of buildings with living space were built before 1970, and a further 11 % 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 Singen (Hohentwiel)
- Nitrate 18 mg/L – about 36 % of the limit of 50 mg/L and in the medium range – such values occur in catchments shaped by agriculture. Boiling does not reduce nitrate.
- pH 7.39 – 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 Singen (Hohentwiel) in everyday life
At 20.2 °dH, Singen (Hohentwiel) 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 Singen (Hohentwiel) 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 Singen (Hohentwiel) 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 Singen (Hohentwiel) |
|---|---|---|
| Sodium | 20 mg/l | 31 mg/l – above the bottled-water threshold |
| Nitrate | 10 mg/l | 18 mg/l – above the bottled-water threshold |
| Nitrite | 0.02 mg/l | not in the report |
| Sulphate | 240 mg/l | 37 mg/l – not above |
| Fluoride | 0.7 mg/l | not in the report |
| Manganese | 0.05 mg/l | 0.002 mg/l – not above |
| Arsenic | 0.005 mg/l | not in the report |
| Uranium | 0.002 mg/l | not in the report |
Questions about baby food are answered by your midwife, your paediatrician and the health office (Gesundheitsamt).
Frequently asked questions about tap water in Singen (Hohentwiel)
Can you drink the tap water in Singen (Hohentwiel)?
According to the verified values, yes: All tested parameters with a legal limit (8) meet the limits set by the German Drinking Water Ordinance (TrinkwV). WaterScore (provisional): 96.5 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 Singen (Hohentwiel)?
The total hardness is 20.2 °dH – 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 Singen (Hohentwiel)?
The published analysis by Stadtwerke Singen 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.
Do I need to filter my tap water in Singen (Hohentwiel)?
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)96.5 / 100
- Chemical safety100 / 100
- Nutrients100 / 100
- General parameters100 / 100
- Data timeliness86.2 / 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
- Extrakt aus Prüfbericht AR-25-R9-001574-01, Singen / HB Hohentwiel, Probenahme 24.02.2025 (Stadtwerke Singen (Analyse: Eurofins Institut Jäger GmbH)) · SHA-256 of the evaluated file: 3d4b8407e10cbeb5…, checked on 1 November 2026
Suggested citation: Trinkwassermonitor (2025): Tap water in Singen (Hohentwiel). Values according to the water supplier’s test report, sampling date 24 February 2025; at the waterworks, not household plumbing. https://trinkwassermonitor.ink/en/tap-water/singen-hohentwiel/
JSON: /api/v1/evidence?city=singen-hohentwiel
Data as of: 24 February 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 Singen (Hohentwiel). Retrieved from https://trinkwassermonitor.ink/en/tap-water/singen-hohentwiel/.”