Tap water hardness in Niigata
We have published hardness data for 3 cities in Niigata. The median is 33 mg/L; the hardest water is in Nagaoka (35 mg/L), the softest in Niigata (19 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 Niigata, hardest first
| mg/L | mg/L | ||
|---|---|---|---|
| Nagaoka | 35 | 35 | soft |
| Jōetsu | 33 | 33 | soft |
| Niigata | 19 | 19 | soft |