Tap water hardness in Gyeonggi-do
We have published hardness data for 25 cities in Gyeonggi-do. The median is 68 mg/L; the hardest water is in Pyeongtaek (133 mg/L), the softest in Uijeongbu (30 mg/L).
4 % of these cities have hard or very hard water (over 120 mg/L).
Korean waterworks report hardness (경도) in mg/L CaCO₃; the drinking-water standard is 300 mg/L (1,000 mg/L for some sources).
Cities in Gyeonggi-do, hardest first
| mg/L | mg/L | ||
|---|---|---|---|
| Pyeongtaek | 133 | 133 | hard |
| Icheon | 108 | 108 | moderately hard |
| Yeoju | 92 | 92 | moderately hard |
| Gwacheon | 80 | 80 | moderately hard |
| Guri | 75 | 75 | moderately hard |
| Ansan | 74 | 74 | moderately hard |
| Anyang | 74 | 74 | moderately hard |
| Uiwang | 72 | 72 | moderately hard |
| Yongin | 72 | 72 | moderately hard |
| Hanam | 71 | 71 | moderately hard |
| Suwon | 70 | 70 | moderately hard |
| Seongnam | 69 | 69 | moderately hard |
| Gunpo | 68 | 68 | moderately hard |
| Gwangju | 68 | 68 | moderately hard |
| Bucheon | 67 | 67 | moderately hard |
| Gimpo | 66 | 66 | moderately hard |
| Gwangmyeong | 63 | 63 | moderately hard |
| Paju | 63 | 63 | moderately hard |
| Pocheon | 62 | 62 | moderately hard |
| Namyangju | 57 | 57 | soft |
| Yangpyeong | 52 | 52 | soft |
| Yeoncheon | 45 | 45 | soft |
| Dongducheon | 45 | 45 | soft |
| Gapyeong | 44 | 44 | soft |
| Uijeongbu | 30 | 30 | soft |