Water hardness in Oberhausen
10.8 °dH very hard
Tap water in Oberhausen is very hard: 10.8 °dH (192 mg/L · 11.2 gpg · 19.2 °fH).
Source: RWW - Trinkwasserdaten 2025 (Median, Niedrigstwert, Hoechstwert) (2025) · data checked 2026-10-19
Range across supply zones: 102–252 mg/L.
2 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| °dH | mg/L | ||
|---|---|---|---|
| Oberhausen (noerdlich A42 und oestlich A516/A3); works Dorsten-Holsterhausen | 13.5 | 241 | very hard |
| Oberhausen (suedlich A42, oder noerdlich A42 und westlich A516/A3); works Muelheim-Styrum-Ost and -West | 8 | 143 | hard |
Oberhausen is supplied by RWW through two areas: south of the A42, shared with Mülheim, and the north and east, fed from Dorsten-Holsterhausen. The median is 191.9 mg/L CaCO₃ and the range is 101.7 to 251.7 mg/L, so the northern and eastern districts are noticeably harder. Both RWW tables are 2025 data. Check which area your street belongs to before buying a descaler.
German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
Water data
| Total hardness | 10.8 °dH |
|---|
How Oberhausen compares
- Tap water in Oberhausen is 7 % softer than the median of the 809 cities we track in Germany (11.5 °dH).
- By hardness it ranks 449 of 809 in Germany (1 = hardest); 44 % of these cities have softer water.
- In Nordrhein-Westfalen it is number 89 of 153 cities; the regional median is 11.3 °dH.
- Nearest city with clearly softer water: Mülheim an der Ruhr, 5 km away (8.3 °dH).
- Nearest city with clearly harder water: Gladbeck, 15 km away (13.5 °dH).
Ranking of the hardest and softest water in Germany →
What it means at home
- Severe scale: heater elements and washing-machine heaters fail early.
- Detergent use is very high; taps and screens coat within days.
- Dishwasher at maximum salt setting.
- An ion-exchange softener is practically essential; RO for drinking water.
How much salt will you use for softening?
Yes. At this hardness a softener pays for itself through appliance life and detergent.
Descale a coffee machine or kettle about every 1 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Oberhausen
| Brand | Setting for this water |
|---|---|
| Bosch | H03 |
| Miele | 11 °dH |
| AEG / Electrolux | 3 |
| Beko | 3rd |
| Hoover | S2 |
| LG | H2 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is Oberhausen water hard or soft?
It is very hard: 192 mg/L as CaCO₃ (11.2 gpg, 10.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Oberhausen safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
How many grains per gallon is Oberhausen water?
11.2 gpg, equal to 10.8 °dH, 19.2 °fH or 192 mg/L calcium carbonate.
What dishwasher salt setting should I use in Oberhausen?
For 192 mg/L (10.8 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Oberhausen?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: RWW - Trinkwasserdaten 2025 (Median, Niedrigstwert, Hoechstwert) (2025). Method: figure published by the water supplier. RWW - Trinkwasserdaten 2025 (Median, Niedrigstwert, Hoechstwert) · Outdated figure? Tell us