Water hardness and tap water in Rüsselsheim am Main
Landkreis Groß-Gerau, Hessen · Postcode 65428
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 (18), at the waterworks
- Water hardness25.3 °dH, hardNo legal limit, only a range
- Data coverageCore parameters: 6 of 7Score based on complete data
Verified drinking-water values
Note from the test report (in the German original): Analysewerte der Stadtwerke Mainz (Vorlieferant, Wasserwerk Hof Schönau) für das Rüsselsheimer Versorgungsgebiet Altstadt-West, Altstadt-Ost, Eichgrund, Rübgrund, Ramsee, Friedrich-Ebert-Siedlung, Hasengrund, Böllensee-Siedlung, Bauschheim und Berliner Viertel. Gezeigt sind die Werte des 2. Halbjahrs 2025 (Dokument vom 15.01.2026). Die übrigen Stadtteile (Horlache, Haßloch Nord, Alt-Haßloch, Dicker Busch I und II, Kolonie, Königstädten) bekommen Wasser der Hessenwasser mit 19,5 °dH – ebenfalls hart, aber weniger als hier (25,3 °dH). Chlorid liegt mit 205 mg/l bei rund 82 % des Grenzwerts. Die Analyse führt die PFAS-Einzelstoffe auf, alle unter der Bestimmungsgrenze (0,001 bis 0,050 µg/l); eine Summe PFAS-20 und eine Summe der Trihalogenmethane weist sie nicht aus.
Background on household plumbing, not a measurement: in Rüsselsheim am Main, 60 % 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 Rüsselsheim am Main
- Nitrate 2 mg/L – about 4 % of the limit of 50 mg/L and in the unremarkable range. Boiling does not reduce nitrate.
- Lead – not detectable at the waterworks. Lead gets into the water almost only through old lead pipes in household plumbing, not via the supplier.
- Uranium 0.7 µg/L – unremarkable against a limit of 10 µg/L. In some regions uranium occurs naturally from the rock (geogenic).
- pH 7.33 – 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 Rüsselsheim am Main in everyday life
At 25.3 °dH, Rüsselsheim am Main 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 Rüsselsheim am Main 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 Rüsselsheim am Main 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)
| Substance | Maximum level | Value in Rüsselsheim am Main |
|---|---|---|
| Sodium | 20 mg/l | 78.6 mg/l – above |
| Nitrate | 10 mg/l | 2 mg/l – not above |
| Nitrite | 0.02 mg/l | below the detection limit (0.02 mg/l) – not above |
| Sulphate | 240 mg/l | 110 mg/l – not above |
| Fluoride | 0.7 mg/l | below the detection limit (0.2 mg/l) – not above |
| Manganese | 0.05 mg/l | below the detection limit (0.005 mg/l) – not above |
| Arsenic | 0.005 mg/l | below the detection limit (0.001 mg/l) – not above |
| Uranium | 0.002 mg/l | 0.0007 mg/l – not above |
Against the other thresholds of Annex 6, the water would qualify as: containing calcium (Calcium 151 mg/l, threshold above 150 mg/l).
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. Questions about baby food are answered by your midwife, your paediatrician and the health office (Gesundheitsamt).
Frequently asked questions about tap water in Rüsselsheim am Main
Can you drink the tap water in Rüsselsheim am Main?
According to the verified values, yes: All tested parameters with a legal limit (18) meet the limits set by the German Drinking Water Ordinance (TrinkwV). WaterScore: 97.6 out of 100 (data coverage: 6 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 Rüsselsheim am Main?
The total hardness is 25.3 °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.
Do I need to filter my tap water in Rüsselsheim am Main?
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
- Total97.6 / 100
- Chemical safety100 / 100
- Heavy metals100 / 100
- Nutrients100 / 100
- General parameters80.8 / 100
- Data timeliness100 / 100
- Data quality100 / 100
Data coverage: 6 of 7 core parameters. Not in the test report: PFAS (sum). Missing parameters are neither estimated nor counted as harmless: the score is based only on the values available. It is not a health assessment and says nothing about the water beyond the service connection. Methodology v3: how we calculate the WaterScore.
Evidence: cite and check
- Analysewerte Stadtwerke Mainz 2025 (2. Halbjahr 2025, Dokument vom 15.01.2026) (Stadtwerke Mainz AG (Vorlieferant) / Wasserversorgung Rüsselsheim GmbH (Netzbetreiber)) · SHA-256 of the evaluated file: 47e24efe73a42fbc…, checked on 3 October 2026
Suggested citation: Trinkwassermonitor (2025): Tap water in Rüsselsheim am Main. Values according to the water supplier’s test report, sampling date 2025; at the waterworks, not household plumbing. https://trinkwassermonitor.ink/en/tap-water/ruesselsheim-am-main/
JSON: /api/v1/evidence?city=ruesselsheim-am-main
Data as of: 2025 · verified: 27 of 27 evaluated parameters.
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 Rüsselsheim am Main. Retrieved from https://trinkwassermonitor.ink/en/tap-water/ruesselsheim-am-main/.”