Tap water hardness in Noord-Holland
We have published hardness data for 5 cities in Noord-Holland. The median is 7.8 °dH; the hardest water is in Amsterdam (7.8 °dH), the softest in Andijk (7.6 °dH).
100 % of these cities have hard or very hard water (over 120 mg/L).
Dutch suppliers report °dH; most networks are softened centrally to 5.6–8.4 °dH.
Cities in Noord-Holland, hardest first
| °dH | mg/L | ||
|---|---|---|---|
| Amsterdam | 7.8 | 139 | hard |
| Diemen | 7.8 | 139 | hard |
| Heemstede | 7.8 | 139 | hard |
| Ouderkerk aan de Amstel | 7.8 | 139 | hard |
| Andijk | 7.6 | 136 | hard |