How hard is the water in Rio Grande County, CO?
7.7 grains per gallon
A softener is worth it here.
The median hardness measured in Rio Grande County, CO is 133 mg/L as calcium carbonate, which is 7.7 gpg. That is hard on the USGS scale. It comes from 31 samples at 26 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 2.8 and 9.3 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 7.7 gpg a softener is worth getting, mainly to protect the water heater and cut soap use. Get at least two quotes, ask each installer what grain capacity they are fitting, and check it against the sizing table below. Because Rio Grande County straddles a decision line, check your own tap with a $10 test strip before you spend anything.
More on sizing a softener for your household.
From 1.6 to 15.8 gpg
The softest single sample on record in Rio Grande County was 28.1 mg/L and the hardest 270 mg/L, a 10-fold gap. The top quarter of sites read above 9.3 gpg and the bottom quarter below 2.8 gpg. So even here some sites draw water soft enough to need nothing at all.
Wells 7.7 gpg, rivers and lakes 2.3 gpg
31 groundwater samples from 26 wells put the median at 132.5 mg/L. 1,666 surface samples from 83 sites put it at 40 mg/L. In Rio Grande County the wells come out 5.4 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. A utility here that draws from the river 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 169 lb of salt a year (5 bags of 40 lb, about $30), 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 $130 a year.
Sizing at 7.7 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 462 | 24,000 | 56 lb |
| 2 | 924 | 24,000 | 112 lb |
| 4 | 1,848 | 24,000 | 225 lb |
| 6 | 2,772 | 24,000 | 337 lb |
Rio Grande County against the rest of Colorado
Among the 63 Colorado counties with data, Rio Grande County is number 43 of 63 counting from the hardest. Across the whole country it is harder than 42% of counties.
Softest in Colorado: Larimer County at 0.4 gpg. Hardest: Mesa County at 143.7 gpg. Closest to Rio Grande County: Lake County (7.7), Jefferson County (7.6), Mineral County (8.2).