Tap water hardness in Harjumaa
We have published hardness data for 11 cities in Harjumaa. The median is 2.02 mmol/L; the hardest water is in Peetri (3.4 mmol/L), the softest in Laagri (0.87 mmol/L).
82 % of these cities have hard or very hard water (over 120 mg/L).
Estonian laboratories report total hardness (üldkaredus) in mmol/L or mg-eq/L (1 mmol/L = 2 mg-eq/L = 100 mg/L CaCO₃); groundwater supplies are mostly hard.
Cities in Harjumaa, hardest first
| mmol/L | mg/L | ||
|---|---|---|---|
| Peetri | 3.4 | 340 | very hard |
| Viimsi | 2.9 | 290 | very hard |
| Tallinn | 2.35 | 235 | very hard |
| Vaida | 2.3 | 230 | very hard |
| Kose | 2.15 | 215 | very hard |
| Paldiski | 2.02 | 202 | very hard |
| Jüri | 1.95 | 195 | very hard |
| Muraste | 1.5 | 150 | hard |
| Saku | 1.2 | 120 | hard |
| Kuusalu | 1.15 | 115 | moderately hard |
| Laagri | 0.87 | 87 | moderately hard |