How hard is the water in Asotin County, WA?
7.3 grains per gallon
A softener is worth it here.
The median hardness measured in Asotin County, WA is 125 mg/L as calcium carbonate, which is 7.3 gpg. That is hard on the USGS scale. It comes from 11 samples at 3 sites between 1990 and 2016, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 5.5 and 7.4 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 7.3 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 Asotin 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 3.6 to 7.6 gpg
The softest single sample on record in Asotin County was 62 mg/L and the hardest 130 mg/L, a 2-fold gap. The top quarter of sites read above 7.4 gpg and the bottom quarter below 5.5 gpg.
Wells 3.6 gpg, rivers and lakes 7.4 gpg
1 groundwater samples from 1 wells put the median at 62 mg/L. 10 surface samples from 2 sites put it at 127.5 mg/L. In Asotin County the rivers and lakes come out 3.8 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 159 lb of salt a year (4 bags of 40 lb, about $29), 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 $129 a year.
Sizing at 7.3 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 438 | 24,000 | 53 lb |
| 2 | 876 | 24,000 | 107 lb |
| 4 | 1,752 | 24,000 | 213 lb |
| 6 | 2,628 | 24,000 | 320 lb |
Asotin County against the rest of Washington
Among the 38 Washington counties with data, Asotin County is number 11 of 38 counting from the hardest. Across the whole country it is harder than 40% of counties.
Softest in Washington: Chelan County at 0.6 gpg. Hardest: Island County at 20.7 gpg. Closest to Asotin County: Okanogan County (7.3), Pend Oreille County (7.6), Ferry County (7.8).