
Colorado
The 16 hardness figures we’ve verified run from 1.2 to 16 grains per gallon, with a median of 6.8; 38% are hard or very hard.
How the 16 figures spread across the bands
- Soft 0
- Slightly hard 3
- Moderately hard 7
- Hard 3
- Very hard 3
- Hardness
- 6.8 gpg medianAverage 7.0 gpg (120 ppm), from 1.2 to 16. Each published figure counts once in the average, median and spread; a figure published as a range is shown as its range and isn't averaged.
- Coverage
- 17 places17 listings as published
- Disinfectant
- 2 of 5use chloramine; 3 use chlorine
Every place we have
Sources are each city’s water quality report or its utility. Gather the listings up by place or by the water system that serves them, or see every listing as published; open a group to see what’s in it.
17 places
| On the scale | Disinfectant | Sources | Ask Aqua | ||
|---|---|---|---|---|---|
Commerce City No source linked
|
16 gpg276 ppm, very hard | SoftSlightly hardModerately hardHardVery hardVery hard 16 gpg |
– | ||
Centennial No source linked
|
12 gpg205 ppm, very hard | SoftSlightly hardModerately hardHardVery hardVery hard 12 gpg |
– | ||
Thornton No source linked
|
12 gpg196 ppm, very hard | SoftSlightly hardModerately hardHardVery hardVery hard 12 gpg |
– | ||
Arvada No source linked
|
9.0 gpg158 ppm, hard | SoftSlightly hardModerately hardHardVery hardHard 9.0 gpg |
– | ||
Castle Rock No source linked
|
8.9 gpg152 ppm, hard | SoftSlightly hardModerately hardHardVery hardHard 8.9 gpg |
– | ||
Aurora 2 notes
|
7.8 gpg132 ppm, hard | SoftSlightly hardModerately hardHardVery hardHard 7.8 gpg |
Chlorine | Disinfectant | |
Pueblo No source linked
|
6.9 gpg117 ppm, moderately hard | SoftSlightly hardModerately hardHardVery hardModerately hard 6.9 gpg |
– | ||
Westminster No source linked
|
6.9 gpg118 ppm, moderately hard | SoftSlightly hardModerately hardHardVery hardModerately hard 6.9 gpg |
– | ||
Colorado Springs No source linked
|
6.6 gpg113 ppm, moderately hard | SoftSlightly hardModerately hardHardVery hardModerately hard 6.6 gpg |
Chlorine | Disinfectant | |
Fort Collins No source linked
|
6.0 gpg111 ppm, moderately hard | SoftSlightly hardModerately hardHardVery hardModerately hard 6.0 gpg |
Chlorine | Disinfectant | |
Denver No source linked
|
5.8 gpg98 ppm, moderately hard | SoftSlightly hardModerately hardHardVery hardModerately hard 5.8 gpg |
Chloramine | Disinfectant | |
Durango No source linked
|
5.0 gpg89 ppm, moderately hard | SoftSlightly hardModerately hardHardVery hardModerately hard 5.0 gpg |
– | ||
Broomfield No source linked
|
4.9 gpg83 ppm, moderately hard | SoftSlightly hardModerately hardHardVery hardModerately hard 4.9 gpg |
– | ||
Boulder No source linked
|
2.4 gpg41 ppm, slightly hard | SoftSlightly hardModerately hardHardVery hardSlightly hard 2.4 gpg |
– | ||
Loveland No source linked
|
1.3 gpg22 ppm, slightly hard | SoftSlightly hardModerately hardHardVery hardSlightly hard 1.3 gpg |
– | ||
Longmont No source linked
|
1.2 gpg20 ppm, slightly hard | SoftSlightly hardModerately hardHardVery hardSlightly hard 1.2 gpg |
– | ||
Lakewood |
– | Chloramine | Disinfectant |
Missing your city? Aquatell researches cities on request from the utility’s own reports, usually within a week. A note on a figure says what we found when we checked it: units that didn’t agree, another page with a different figure, a range.
What to do about it
Hard water
Above about 3.5 grains per gallon, scale builds in water heaters, fixtures and appliances. A softener sized for your hardness and household removes it for the whole house.
Chlorine or chloramine
Standard carbon removes chlorine’s taste and smell. Chloramine lasts longer in the pipes and needs catalytic carbon to remove it.
Not sure what you need?
Aqua knows these figures and Aquatell’s treatment charts, and can size a system for your home.




