How hard is the water in Benewah County, ID?
4.8 grains per gallon
Optional: a softener helps, but plenty of homes skip it.
The median hardness measured in Benewah County, ID is 83 mg/L as calcium carbonate, which is 4.8 gpg. That is moderately hard on the USGS scale. It comes from 154 samples at 43 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 3.7 and 6.5 gpg. The whole middle of that range gives the same answer, so a test of your own tap is unlikely to change it. Confidence in the county figure: high (how it is measured).
What to do next
At 4.8 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.
More on when a softener is not worth it.
From 0.7 to 30.0 gpg
The softest single sample on record in Benewah County was 11.4 mg/L and the hardest 513.5 mg/L, a 45-fold gap. The top quarter of sites read above 6.5 gpg and the bottom quarter below 3.7 gpg.
Wells 4.8 gpg, rivers and lakes 1.1 gpg
154 groundwater samples from 43 wells put the median at 82.5 mg/L. 262 surface samples from 10 sites put it at 19 mg/L. In Benewah County the wells come out 3.7 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 105 lb of salt a year (3 bags of 40 lb, about $19), 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 $119 a year.
Sizing at 4.8 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 288 | 24,000 | 35 lb |
| 2 | 576 | 24,000 | 70 lb |
| 4 | 1,152 | 24,000 | 140 lb |
| 6 | 1,728 | 24,000 | 210 lb |
Benewah County against the rest of Idaho
Among the 44 Idaho counties with data, Benewah County is number 38 of 44 counting from the hardest. Across the whole country it is harder than 30% of counties.
Softest in Idaho: Valley County at 1.3 gpg. Hardest: Caribou County at 23 gpg. Closest to Benewah County: Gem County (5.3), Elmore County (4.4), Idaho County (5.5).