Water hardness and tap water in Langenfeld (Rheinland)
Kreis Mettmann, Nordrhein-Westfalen · Postcode 40764
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 hardness12.1 °dH, mediumNo legal limit, only a range
- Data coverageCore parameters: 7 of 7Score based on complete data
Verified drinking-water values
Note from the test report (in the German original): Trinkwasseranalyse von März 2026 (ein genauer Tag ist nicht angegeben). Langenfeld und Monheim werden aus einer gemeinsamen Aufbereitungsanlage in Monheim versorgt. Die Werte stammen aus der Spalte „Hochbehälter Langenfeld“; Nitrat, Fluorid, PFAS und Uran werden – als Parameter, die sich im Verteilnetz nicht mehr erhöhen – nur an der Aufbereitungsanlage Monheim gemessen und sind entsprechend gekennzeichnet. Die Summe PFAS-20 liegt mit 0,040 µg/l unter dem Grenzwert von 0,10 µg/l.
Background on household plumbing, not a measurement: in Langenfeld (Rheinland), 37 % of buildings with living space were built before 1970, and a further 15 % 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 Langenfeld (Rheinland)
- Nitrate 19.7 mg/L – about 39 % 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.
- PFAS (sum of PFAS-20) 40 ng/L – about 40 % of the limit of 100 ng/L (since 12 January 2026).
- 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 – not detectable at the waterworks (limit 10 µg/L).
- pH 7.8 – 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 Langenfeld (Rheinland) in everyday life
At 12.1 °dH, Langenfeld (Rheinland) 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 Langenfeld (Rheinland) 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 Langenfeld (Rheinland) 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 Langenfeld (Rheinland) |
|---|---|---|
| Sodium | 20 mg/l | 25.3 mg/l – above |
| Nitrate | 10 mg/l | 19.7 mg/l – above |
| Nitrite | 0.02 mg/l | below the detection limit (0.02 mg/l) – not above |
| Sulphate | 240 mg/l | 56.3 mg/l – not above |
| Fluoride | 0.7 mg/l | 0.11 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 | below the detection limit (0.0001 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 Langenfeld (Rheinland)
Can you drink the tap water in Langenfeld (Rheinland)?
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: 100 out of 100 (data coverage: 7 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 Langenfeld (Rheinland)?
The total hardness is 12.1 °dH – hardness range “medium”. Dose detergent for the hardness range “medium”.
Is there PFAS in the tap water in Langenfeld (Rheinland)?
Yes, in measurable amounts: according to the published analysis by Verbandswasserwerk Langenfeld-Monheim (as of March 2026), the sum of PFAS-20 is 0.04 µg/l – that is 40 % of the limit of 0.1 µg/l, which has applied since 12 January 2026. Whether the limit of 0.02 µg/l for the sum of PFAS-4, which applies from 12 January 2028, is met cannot be read from the sum of PFAS-20.
Do I need to filter my tap water in Langenfeld (Rheinland)?
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
- PFAS100 / 100
- Nutrients100 / 100
- General parameters100 / 100
- Data timeliness100 / 100
- Data quality100 / 100
Data coverage: 7 of 7 core parameters. 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 Langenfeld und Monheim, März 2026 – Spalten Hochbehälter Langenfeld und Trinkwasseraufbereitungsanlage Monheim (Verbandswasserwerk Langenfeld-Monheim GmbH & Co. KG (über das Wasserportal wasserqualitaet-online.de)) · SHA-256 of the evaluated file: 79109a2e02d1cce2…, checked on 3 October 2026
Suggested citation: Trinkwassermonitor (2026): Tap water in Langenfeld (Rheinland). Values according to the water supplier’s test report, sampling date March 2026; at the waterworks, not household plumbing. https://trinkwassermonitor.ink/en/tap-water/langenfeld-rheinland/
JSON: /api/v1/evidence?city=langenfeld-rheinland
Data as of: March 2026 · verified: 21 of 21 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 Langenfeld (Rheinland). Retrieved from https://trinkwassermonitor.ink/en/tap-water/langenfeld-rheinland/.”