Water hardness and tap water in Krefeld
Krefeld, Nordrhein-Westfalen · Postcode 47798, 47799, 47800, 47802, 47803
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 (9), at the waterworks
- Water hardness13.6 °dH, mediumNo legal limit, only a range
- Data coverageCore parameters: 5 of 7Score based on complete data
Verified drinking-water values
Note from the test report (in the German original): NGN Netzgesellschaft Niederrhein mbH (SWK-Konzern) · Jahresdurchschnittsanalysedaten 2025, Wasserwerk Gladbacher Straße (westliches Stadtgebiet und Hüls). Das zweite Krefelder Wasserwerk 'In der Elt' (östliche Stadtteile) misst deutlich höheres Nitrat (35,1 mg/l) und PFAS (Summe PFAS-20: 0,064 µg/l, Summe PFAS-4: 0,011 µg/l) – beide Werte bleiben klar unter den geltenden Grenzwerten.
Background on household plumbing, not a measurement: in Krefeld, 56 % of buildings with living space were built before 1970, and a further 12 % 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 Krefeld
- Nitrate 8.2 mg/L – about 16 % of the limit of 50 mg/L and in the unremarkable range. Boiling does not reduce nitrate.
- PFAS (sum of PFAS-20) 7 ng/L – about 7 % 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 7.7 – 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 Krefeld in everyday life
At 13.6 °dH, Krefeld 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 Krefeld 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 Krefeld 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 Krefeld |
|---|---|---|
| Sodium | 20 mg/l | 38.1 mg/l – above |
| Nitrate | 10 mg/l | 8.2 mg/l – not above |
| Nitrite | 0.02 mg/l | not in the report |
| Sulphate | 240 mg/l | 114.6 mg/l – not above |
| Fluoride | 0.7 mg/l | not in the report |
| Manganese | 0.05 mg/l | not in the report |
| Arsenic | 0.005 mg/l | not in the report |
| Uranium | 0.002 mg/l | below the detection limit (0.001 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 Krefeld
Can you drink the tap water in Krefeld?
According to the verified values, yes: All tested parameters with a legal limit (9) meet the limits set by the German Drinking Water Ordinance (TrinkwV). WaterScore: 100 out of 100 (data coverage: 5 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 Krefeld?
The total hardness is 13.6 °dH – hardness range “medium”. Dose detergent for the hardness range “medium”.
Is there PFAS in the tap water in Krefeld?
Yes, in measurable amounts: according to the published analysis by NGN Netzgesellschaft Niederrhein (SWK) (as of 2025), the sum of PFAS-20 is 0.007 (middle of the range given by the supplier) µg/l – that is 7 % of the limit of 0.1 µg/l, which has applied since 12 January 2026.
Do I need to filter my tap water in Krefeld?
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: 5 of 7 core parameters. Not in the test report: Nitrite and Arsenic. 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 Krefeld, Wasserwerk Gladbacher Straße, Jahresdurchschnitt 2025 (NGN Netzgesellschaft Niederrhein mbH (SWK-Konzern)) · SHA-256 of the evaluated file: de9dfc5a8fa0b12c…, checked on 3 October 2026
Suggested citation: Trinkwassermonitor (2025): Tap water in Krefeld. Values according to the water supplier’s test report, sampling date 2025; at the waterworks, not household plumbing. https://trinkwassermonitor.ink/en/tap-water/krefeld/
JSON: /api/v1/evidence?city=krefeld
Data as of: 2025 · verified: 13 of 13 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 Krefeld. Retrieved from https://trinkwassermonitor.ink/en/tap-water/krefeld/.”