How hard is the water in Rio Blanco County, CO?
4.3 grains per gallon
Optional: a softener helps, but plenty of homes skip it.
The median hardness measured in Rio Blanco County, CO is 73 mg/L as calcium carbonate, which is 4.3 gpg. That is moderately hard on the USGS scale. It comes from 262 samples at 72 sites between 1990 and 2026, drawn from groundwater wells, which is what most taps and private wells in the county draw on.
How much it varies here
Half the sites came in between 2.1 and 19.7 gpg. That spread crosses a decision line, so some homes here land on a different answer. A $10 test strip on your own tap settles it. Confidence in the county figure: high (how it is measured).
What to do next
At 4.3 gpg this is your call. Look for white film on glasses and crust on the shower head: if you see little of either, you can live without one. If you do want one, a 24,000-grain unit is enough, so ask for that size rather than a bigger one. Because Rio Blanco County straddles a decision line, check your own tap with a $10 test strip before you spend anything.
More on when a softener is not worth it.
From 0.6 to 69.2 gpg
The softest single sample on record in Rio Blanco County was 10.6 mg/L and the hardest 1,185 mg/L, a 112-fold gap. The top quarter of sites read above 19.7 gpg and the bottom quarter below 2.1 gpg.
Wells 4.3 gpg, rivers and lakes 20.6 gpg
262 groundwater samples from 72 wells put the median at 72.9 mg/L. 2,174 surface samples from 194 sites put it at 352 mg/L. In Rio Blanco County the rivers and lakes come out 16.3 gpg harder. Here the surface water reads harder than the wells, which often points to streams fed by limestone springs or irrigation return flow. A utility here that draws from the aquifer can deliver noticeably different water from a private well next door.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 93 lb of salt a year (3 bags of 40 lb, about $17), and roughly 2,346 gallons of regeneration water. Installed, most units run $1,000 to $4,500; spread over 15 years with salt, that is about $117 a year.
Sizing at 4.3 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 258 | 24,000 | 31 lb |
| 2 | 516 | 24,000 | 63 lb |
| 4 | 1,032 | 24,000 | 126 lb |
| 6 | 1,548 | 24,000 | 188 lb |
Rio Blanco County against the rest of Colorado
Among the 63 Colorado counties with data, Rio Blanco County is number 60 of 63 counting from the hardest. Across the whole country it is harder than 27% of counties.
Softest in Colorado: Larimer County at 0.4 gpg. Hardest: Mesa County at 143.7 gpg. Closest to Rio Blanco County: Grand County (4.2), Chaffee County (4.3), Jackson County (4.3).