Tap water hardness in Gunma

We have published hardness data for 11 cities in Gunma. The median is 51 mg/L; the hardest water is in Chiyoda (79 mg/L), the softest in Itakura (41 mg/L).

0 % of these cities have hard or very hard water (over 120 mg/L).

Japanese waterworks report hardness (硬度) in mg/L CaCO₃; the standard is 300 mg/L and the target 10–100 mg/L.

Cities in Gunma, hardest first

All cities in Japan →