How hard is the water in Archuleta County, CO?
5.8 grains per gallon
Optional: a softener helps, but plenty of homes skip it.
The median hardness measured in Archuleta County, CO is 100 mg/L as calcium carbonate, which is 5.8 gpg. That is moderately hard on the USGS scale. It comes from 1,529 samples at 89 sites between 1990 and 2026, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 3.4 and 12.3 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 5.8 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 Archuleta 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 1.3 to 47.9 gpg
The softest single sample on record in Archuleta County was 22 mg/L and the hardest 820 mg/L, a 37-fold gap. The top quarter of sites read above 12.3 gpg and the bottom quarter below 3.4 gpg.
Wells 17 gpg, rivers and lakes 5.1 gpg
2 groundwater samples from 2 wells put the median at 291.5 mg/L. 1,527 surface samples from 87 sites put it at 88 mg/L. In Archuleta County the wells come out 11.9 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 128 lb of salt a year (4 bags of 40 lb, about $23), 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 $123 a year.
Sizing at 5.8 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 348 | 24,000 | 42 lb |
| 2 | 696 | 24,000 | 85 lb |
| 4 | 1,392 | 24,000 | 169 lb |
| 6 | 2,088 | 24,000 | 254 lb |
Archuleta County against the rest of Colorado
Among the 63 Colorado counties with data, Archuleta County is number 53 of 63 counting from the hardest. Across the whole country it is harder than 34% of counties.
Softest in Colorado: Larimer County at 0.4 gpg. Hardest: Mesa County at 143.7 gpg. Closest to Archuleta County: Pitkin County (5.8), Bent County (5.6), Gilpin County (6.3).