How hard is the water in Johnson County, WY?
16.9 grains per gallon
A softener will pay its way here.
The median hardness measured in Johnson County, WY is 290 mg/L as calcium carbonate, which is 16.9 gpg. That is very hard on the USGS scale. It comes from 22 samples at 13 sites between 1990 and 2023, 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 8.2 and 41.6 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: medium (how it is measured).
What to do next
At 16.9 gpg a softener pays its way here. Before you buy, check the quoted unit's grain capacity against the sizing table below, and ask whether it regenerates on demand, which uses less salt than a timer. Call your utility for its own report if you are on city water. Because Johnson 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 0.5 to 105.1 gpg
The softest single sample on record in Johnson County was 9.3 mg/L and the hardest 1,800 mg/L, a 194-fold gap. The top quarter of sites read above 41.6 gpg and the bottom quarter below 8.2 gpg. So even here some sites draw water soft enough to need nothing at all.
Wells 16.9 gpg, rivers and lakes 34.2 gpg
22 groundwater samples from 13 wells put the median at 290 mg/L. 2,022 surface samples from 33 sites put it at 585.5 mg/L. In Johnson County the rivers and lakes come out 17.3 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 370 lb of salt a year (10 bags of 40 lb, about $67), 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 $167 a year.
Sizing at 16.9 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,014 | 24,000 | 123 lb |
| 2 | 2,028 | 24,000 | 247 lb |
| 4 | 4,056 | 32,000 | 493 lb |
| 6 | 6,084 | 48,000 | 740 lb |
Johnson County against the rest of Wyoming
Among the 23 Wyoming counties with data, Johnson County is number 7 of 23 counting from the hardest. Across the whole country it is harder than 76% of counties.
Softest in Wyoming: Park County at 1.4 gpg. Hardest: Natrona County at 124.4 gpg. Closest to Johnson County: Uinta County (14.5), Platte County (14.4), Sweetwater County (14.3).