Water hardness and tap water in Offenburg
Ortenaukreis, Baden-Württemberg · Postcode 77652, 77654, 77656
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 hardness6.1 °dH, softNo 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): Analyse vom 05.03.2026 für das Wasserwerk Am Sägeteich, aus dem laut OWV die Stadt Offenburg mit allen Stadtteilen versorgt wird (Grundwasser des Kinzigtals). Für Nitrat, Fluorid und Uran nennt die Einheitenspalte des Dokuments versehentlich µg/L; Messwerte und Grenzwertspalte entsprechen mg/L und sind hier so übernommen. Werte „< BG“ liegen unter der Bestimmungsgrenze, die das Dokument nicht beziffert.
Background on household plumbing, not a measurement: in Offenburg, 49 % 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 Offenburg
- Nitrate 10.2 mg/L – about 20 % 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) 4.1 ng/L – about 4 % 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 0.5 µg/L – unremarkable against a limit of 10 µg/L. In some regions uranium occurs naturally from the rock (geogenic).
- pH 7.96 – 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 Offenburg in everyday life
At 6.1 °dH, Offenburg is in the hardness range “soft” (soft: below 8.4 °dH, medium: 8.4–14 °dH, hard: above 14 °dH).
- Dose detergent for the hardness range “soft” – the lowest amount on the pack.
- Limescale deposits are rare; kettles and coffee machines only need descaling every few months.
- At this hardness you do not need limescale protection or a water softener.
Baby food and low sodium: tap water in Offenburg 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 Offenburg 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 Offenburg |
|---|---|---|
| Sodium | 20 mg/l | 11.3 mg/l – not above |
| Nitrate | 10 mg/l | 10.2 mg/l – above |
| Nitrite | 0.02 mg/l | below the limit of quantification – cannot be assessed |
| Sulphate | 240 mg/l | 17.4 mg/l – not above |
| Fluoride | 0.7 mg/l | 0.13 mg/l – not above |
| Manganese | 0.05 mg/l | below the limit of quantification – cannot be assessed |
| Arsenic | 0.005 mg/l | below the limit of quantification – cannot be assessed |
| Uranium | 0.002 mg/l | 0.0005 mg/l – not above |
Against the other thresholds of Annex 6, the water would qualify as: low in sodium (“suitable for a low-sodium diet”) (Sodium 11.3 mg/l, threshold below 20 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 Offenburg
Can you drink the tap water in Offenburg?
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: 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 Offenburg?
The total hardness is 6.1 °dH – hardness range “soft”. Dose detergent for the hardness range “soft” – the lowest amount on the pack.
Is there PFAS in the tap water in Offenburg?
Yes, in measurable amounts: according to the published analysis by Offenburger Wasserversorgung (OWV) (as of 5 March 2026), the sum of PFAS-20 is 0.0041 µg/l – that is 4 % of the limit of 0.1 µg/l, which has applied since 12 January 2026. Even this sum of all 20 substances is below the limit of 0.02 µg/l that applies from 12 January 2028 to the sum of four of them (PFAS-4).
Do I need to filter my tap water in Offenburg?
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 Offenburg (WW Am Sägeteich) vom 05.03.2026 (Offenburger Wasserversorgung GmbH / badenova Netze (über das Wasserportal wasserqualitaet-online.de)) · SHA-256 of the evaluated file: 90cedd7801465802…, checked on 3 October 2026
Suggested citation: Trinkwassermonitor (2026): Tap water in Offenburg. Values according to the water supplier’s test report, sampling date 5 March 2026; at the waterworks, not household plumbing. https://trinkwassermonitor.ink/en/tap-water/offenburg/
JSON: /api/v1/evidence?city=offenburg
Data as of: 5 March 2026 · verified: 24 of 24 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 Offenburg. Retrieved from https://trinkwassermonitor.ink/en/tap-water/offenburg/.”