Is Colorado tap water hard or soft?
Mostly not. 27 % of the 11 cities with published data in Colorado have hard or very hard water (over 120 mg/L). The median is 6.1 gpg, from 1.3 gpg in Longmont to 10.5 gpg in Pueblo.
We have published hardness data for 11 cities in Colorado. The median is 6.1 gpg; the hardest water is in Pueblo (10.5 gpg), the softest in Longmont (1.3 gpg).
27 % of these cities have hard or very hard water (over 120 mg/L).
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Cities in Colorado, hardest first
| gpg | mg/L | ||
|---|---|---|---|
| Pueblo | 10.5 | 180 | very hard |
| Castle Pines | 8.5 | 146 | hard |
| Aurora | 7.9 | 136 | hard |
| Centennial | 6.7 | 115 | moderately hard |
| Durango | 6.4 | 109 | moderately hard |
| Denver | 6.1 | 105 | moderately hard |
| Commerce City | 5.2 | 89 | moderately hard |
| Broomfield | 4.8 | 82 | moderately hard |
| Boulder | 2.5 | 42 | soft |
| Firestone | 1.9 | 33 | soft |
| Longmont | 1.3 | 22 | soft |
FAQ
Is Colorado water hard or soft?
Mostly not. 27 % of the 11 cities we cover have hard or very hard water; the median is 6.1 gpg.
Which city in Colorado has the hardest water?
Pueblo, at 10.5 gpg, has the hardest water of the 11 cities with published data.
Which city in Colorado has the softest water?
Longmont, at 1.3 gpg, has the softest water of the 11 cities with published data.
Do I need a water softener in Colorado?
Above about 120 mg/L (7 gpg) scale builds up in water heaters, kettles and dishwashers, and a softener or at least regular descaling pays off. Look up your own city in the table: in Colorado the values range from 1.3 gpg to 10.5 gpg.
On a private well? Well water hardness in Colorado by county →