Water hardness and tap water in Hanau

Name: Water hardness and tap water in Hanau
Creator: Trinkwassermonitor
License: https://creativecommons.org/licenses/by/4.0/

Main-Kinzig-Kreis, Hessen · Postcode 63450, 63452, 63454, 63456, 63457

This page is a translation of the German version; the German page is authoritative. German version · Report a translation error

Short answer: The tap water in Hanau has a total hardness of 13.55 °dH, hardness range “medium” (as of January 2026). All tested parameters with a legal limit (17) meet the limits set by the German Drinking Water Ordinance (TrinkwV). Source: test report by Stadtwerke Hanau. WaterScore: 100 out of 100 (data coverage: 6 of 7 core parameters).

Limits of the Drinking Water OrdinancemetAll tested parameters (17), at the waterworks
Water hardness13.55 °dH, mediumNo legal limit, only a range
Data coverageCore parameters: 6 of 7Score based on complete data

Verified drinking-water values

Parameter	Value	Limit (TrinkwV)	Sampling date	Source	Status
Nitrate	4.6 mg/L	50 mg/L	January 2026	Stadtwerke Hanau GmbH	verified
Nitrite	< 0.03 mg/L	0.5 mg/L	January 2026	Stadtwerke Hanau GmbH	verified
Lead	0.000054 mg/L	0.01 mg/L from 12 January 2028: 0.005 mg/L	January 2026	Stadtwerke Hanau GmbH	verified
Arsenic	0.000074 mg/L	0.01 mg/L new plants from 2028, all from 2036: 0.004 mg/L	January 2026	Stadtwerke Hanau GmbH	verified
Uranium	0.000115 mg/L	0.01 mg/L	January 2026	Stadtwerke Hanau GmbH	verified
Mercury	< 0.000002 mg/L	0.001 mg/L	January 2026	Stadtwerke Hanau GmbH	verified
Copper	< 0.005 mg/L	2 mg/L	January 2026	Stadtwerke Hanau GmbH	verified
Cadmium	< 0.000005 mg/L	0.003 mg/L	January 2026	Stadtwerke Hanau GmbH	verified
Chromium	< 0.00005 mg/L	0.025 mg/L from 12 January 2030: 0.005 mg/L	January 2026	Stadtwerke Hanau GmbH	verified
Nickel	0.000455 mg/L	0.02 mg/L	January 2026	Stadtwerke Hanau GmbH	verified
Chloride	56.15 mg/L 22 % of the limit	250 mg/L	January 2026	Stadtwerke Hanau GmbH	verified
Sulphate	73.6 mg/L 29 % of the limit	250 mg/L	January 2026	Stadtwerke Hanau GmbH	verified
Sodium	29.3 mg/L 15 % of the limit	200 mg/L	January 2026	Stadtwerke Hanau GmbH	verified
Calcium	73.4 mg/L	–	January 2026	Stadtwerke Hanau GmbH	verified
Magnesium	14.25 mg/L	–	January 2026	Stadtwerke Hanau GmbH	verified
pH	7.63	6.5–9.5	January 2026	Stadtwerke Hanau GmbH	verified
Total hardness	13.55 °dH (medium)	no legal limit	January 2026	Stadtwerke Hanau GmbH	verified
Electrical conductivity	442 µS/cm	–	January 2026	Stadtwerke Hanau GmbH	verified
Fluoride	0.1 mg/L	1.5 mg/L	January 2026	Stadtwerke Hanau GmbH	verified
Iron	< 0.005 mg/L	0.2 mg/L	January 2026	Stadtwerke Hanau GmbH	verified
Ammonium	< 0.026 mg/L	0.5 mg/L	January 2026	Stadtwerke Hanau GmbH	verified
Coliform bacteria	0 KBE/100ml	0 per 100 ml	January 2026	Stadtwerke Hanau GmbH	verified

Note from the test report (in the German original): Stadtwerke Hanau · Trinkwasseranalyse für das Versorgungsgebiet Innenstadt aus dem Wasserwerk Leipziger Straße, Stand 01/2026. Die Stadtwerke geben Schwankungsbereiche an, weil sich Rohwasser und Brunnenbetrieb im Jahresverlauf ändern; gezeigt ist jeweils die Mitte der Spanne, die Spanne selbst steht in der Originalangabe. Die Gesamthärte schwankt zwischen 13,0 und 14,1 °dH und erreicht damit zeitweise knapp den Härtebereich hart – die Stadtwerke ordnen die Innenstadt „mittel / hart“ zu. Hanau wird aus sechs Wasserwerken versorgt; welches Ihre Straße beliefert, zeigt der Wasserwerksfinder der Stadtwerke. Die übrigen Gebiete: Großauheim (Wasserwerk Bruchwiesen 6,05–8,33 °dH, weich; Wasserwerk Wallersee 20,6–22,2 °dH, hart), Wolfgang und Lamboy (Großkrotzenburg, 6,69–8,23 °dH, weich), Mittelbuchen (17,5–19,0 °dH, hart) sowie Kesselstadt, Wilhelmsbad und Hohe Tanne (Wilhelmsbad, 24,2–25,2 °dH, hart). PFAS-20 und PFAS-4 führt die Tabelle ohne Analysewert; laut Stadtwerken sind im Trinkwasser des Wasserwerks keine Rückstände nachweisbar.

Is a value wrong or out of date? Report an error – we check every report against the original source.

Water at your own tap: The values describe the water the supplier delivers – not automatically the water at your tap. The water supplier is responsible up to the service connection (Hausanschluss); the building owner is responsible for the pipes beyond it. Lead can dissolve from lead pipes, leaded solder joints or old brass fittings, especially when water has stood in the pipes for a long time (stagnant water); this mainly affects buildings constructed before about 1973. If water has stood in the pipes for several hours, let it run until it comes out cool. If you suspect lead pipes, a lead analysis of the stagnant water by an accredited laboratory will help.

What the values mean for Hanau

Nitrate 4.6 mg/L – about 9 % of the limit of 50 mg/L and in the unremarkable range. Boiling does not reduce nitrate.
Lead 0.054 µg/L – about 1 % of the limit of 10 µg/L, measured at the waterworks. Today’s limit is met; it will drop to 5 µg/L on 12 January 2028. Lead from household plumbing (old lead pipes) comes on top of this and is not covered by this value.
Uranium 0.11 µg/L – unremarkable against a limit of 10 µg/L. In some regions uranium occurs naturally from the rock (geogenic).
pH 7.63 – 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 Hanau in everyday life

At 13.55 °dH, Hanau is in the hardness range “medium” (soft: below 8.4 °dH, medium: 8.4–14 °dH, hard: above 14 °dH).

Dose detergent for the hardness range “medium”.
As a rule of thumb, descale the kettle about every four to six weeks and the coffee machine as the manufacturer recommends.
A limescale protection device is not a must at medium hardness; regular descaling is often enough.

Baby food and low sodium: tap water in Hanau 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 Hanau 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)

Values at the waterworks next to the maximum levels for bottled water “suitable for infant food”
Substance	Maximum level	Value in Hanau
Sodium	20 mg/l	29.3 mg/l – above
Nitrate	10 mg/l	4.6 mg/l – not above
Nitrite	0.02 mg/l	below the detection limit (0.03 mg/l) – cannot be assessed
Sulphate	240 mg/l	73.6 mg/l – not above
Fluoride	0.7 mg/l	0.1 mg/l – not above
Manganese	0.05 mg/l	not in the report
Arsenic	0.005 mg/l	0.000074 mg/l – not above
Uranium	0.002 mg/l	0.000115 mg/l – not above

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 Hanau

Can you drink the tap water in Hanau?

According to the verified values, yes: All tested parameters with a legal limit (17) meet the limits set by the German Drinking Water Ordinance (TrinkwV). WaterScore: 100 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 Hanau?

The total hardness is 13.55 °dH – hardness range “medium”. Dose detergent for the hardness range “medium”.

Is there PFAS in the tap water in Hanau?

The published analysis by Stadtwerke Hanau 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 Hanau?

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

Total100 / 100
Chemical safety100 / 100
Heavy metals100 / 100
Nutrients100 / 100
General parameters100 / 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

Trinkwasseranalyse für das Versorgungsgebiet Innenstadt (Wasserwerk Leipziger Straße), Stand 01/2026 (Stadtwerke Hanau GmbH)

Suggested citation: Trinkwassermonitor (2026): Tap water in Hanau. Values according to the water supplier’s test report, sampling date January 2026; at the waterworks, not household plumbing. https://trinkwassermonitor.ink/en/tap-water/hanau/

JSON: /api/v1/evidence?city=hanau

Data as of: January 2026 · verified: 22 of 22 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 Hanau. Retrieved from https://trinkwassermonitor.ink/en/tap-water/hanau/.”