State distribution
Hardness across indexed ZIPs
Counts describe published ZIP profiles, not a population-weighted statewide sample.
Soft · 0–60 PPM82
Moderately hard · 61–120 PPM17
Hard · 121–180 PPM11
Very hard · 181+ PPM51
State water index
Colorado water hardness
Search 58 indexed communities and 161 ZIP profiles, then compare the underlying utility, source, distance, and reporting context.
Median indexed hardness
59PPM
Soft
Indexed range 13.7–829 PPM
- ZIP profiles
- 161
- Cities
- 58
- Matched utilities
- 94
- Counties
- 36
Understanding Colorado
Why local comparisons matter here
Colorado contains high mountain headwaters, Front Range systems, western valleys, and eastern plains aquifers. Elevation and source geology create sharp local contrasts.
In this index, soft is the largest category, covering 82 of 161 profiles with hardness data. The state median is 59 PPM, but the full indexed range is 13.7–829 PPM.
Evidence coverage
What the current records support
- Hardness estimate
- 100%
- Lead 90th percentile
- 98%
- Copper 90th percentile
- 4%
9
Low-confidence hardness profiles
9
Nearest site more than 25 miles away
Reported source water
Utility source mix
- Surface water
- 77
- Groundwater
- 15
- Groundwater influenced by surface water
- 2
Highest medians
Hardest indexed cities
- 1. Yuma829 PPM
- 2. Las Animas812 PPM
- 3. La Junta750 PPM
- 4. Wray731 PPM
- 5. Holyoke716 PPM
Lowest medians
Softest indexed cities
- 1. Greeley14 PPM
- 2. Evans14 PPM
- 3. Loveland17 PPM
- 4. Berthoud30 PPM
- 5. Dacono32 PPM
City directory
Explore Colorado by city
Search by city or county, then sort by name, hardness, or ZIP coverage.
58 cities · 161 ZIP profiles
58 cities found
Page 1 of 3
Alamosa
Alamosa County · 1 ZIP
109PPM
Single indexed valueNo active flag
Arvada
Jefferson County · 5 ZIPs
57PPM
Range 54.9–58.8No active flag
Aspen
Pitkin County · 1 ZIP
93PPM
Single indexed valueNo active flag
Aurora
Arapahoe County · 11 ZIPs
54PPM
Range 24.6–60.6No active flag
Bayfield
La Plata County · 1 ZIP
144PPM
Single indexed valueNo active flag
Berthoud
Larimer County · 1 ZIP
30PPM
Single indexed valueNo active flag
Black Hawk
Gilpin County · 1 ZIP
54PPM
Single indexed valueNo active flag
Boulder
Boulder County · 5 ZIPs
43PPM
Range 40.1–45.8No active flag
Brighton
Adams County · 1 ZIP
44PPM
Single indexed valueNo active flag
Broomfield
Broomfield County · 2 ZIPs
46PPM
Range 45–47.8No active flag
Burlington
Kit Carson County · 1 ZIP
141PPM
Single indexed valueNo active flag
Colorado Springs
El Paso County · 25 ZIPs
206PPM
Range 108–218.5No active flag
Cortez
Montezuma County · 1 ZIP
153PPM
Single indexed valueNo active flag
Craig
Moffat County · 1 ZIP
170PPM
Single indexed valueNo active flag
Crested Butte
Gunnison County · 1 ZIP
212PPM
Single indexed valueNo active flag
Cripple Creek
Teller County · 1 ZIP
110PPM
Single indexed valueNo active flag
Dacono
Weld County · 1 ZIP
32PPM
Single indexed valueNo active flag
Delta
Delta County · 1 ZIP
289PPM
Single indexed valueNo active flag
Denver
Jefferson County · 33 ZIPs
54PPM
Range 23.3–60.6No active flag
Durango
La Plata County · 3 ZIPs
147PPM
Range 145.5–1491 active record
Englewood
Arapahoe County · 1 ZIP
57PPM
Single indexed valueNo active flag
Evans
Weld County · 2 ZIPs
14PPM
Single indexed valueNo active flag
Florence
Fremont County · 1 ZIP
205PPM
Single indexed valueNo active flag
Fountain
El Paso County · 2 ZIPs
228PPM
Range 225–231.5No active flag
County comparison
Highest indexed county medians
| County | Median | Range | ZIP profiles |
|---|---|---|---|
| Bent County | 812 PPM | 812–812 | 1 |
| Yuma County | 780 PPM | 730.5–829 | 2 |
| Phillips County | 716 PPM | 716–716 | 1 |
| Prowers County | 703 PPM | 703–703 | 1 |
| Huerfano County | 521 PPM | 520.5–520.5 | 1 |
| Otero County | 447 PPM | 144–749.5 | 2 |
| Logan County | 412 PPM | 412–412 | 1 |
| Mesa County | 382 PPM | 373–389 | 4 |
| Delta County | 246 PPM | 203.5–288.5 | 2 |
| San Miguel County | 245 PPM | 245–245 | 1 |
| Montrose County | 235 PPM | 232.5–236.5 | 2 |
| Pueblo County | 232 PPM | 224–240 | 6 |