How hard is the water in Gilliam County, OR?
5.6 grains per gallon
Optional: a softener helps, but plenty of homes skip it.
The median hardness measured in Gilliam County, OR is 96 mg/L as calcium carbonate, which is 5.6 gpg. That is moderately hard on the USGS scale. It comes from 252 samples at 46 sites between 1991 and 2024, 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 5.1 and 6.4 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 5.6 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 0.5 to 51.3 gpg
The softest single sample on record in Gilliam County was 7.8 mg/L and the hardest 879 mg/L, a 113-fold gap. The top quarter of sites read above 6.4 gpg and the bottom quarter below 5.1 gpg.
Wells 5.6 gpg, rivers and lakes 4.7 gpg
252 groundwater samples from 46 wells put the median at 96 mg/L. 54 surface samples from 7 sites put it at 81.3 mg/L. In Gilliam County the wells come out 0.9 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. The two sources are close, so the county figure should hold whichever one your tap is on.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 122 lb of salt a year (4 bags of 40 lb, about $22), 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 $122 a year.
Sizing at 5.6 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 336 | 24,000 | 41 lb |
| 2 | 672 | 24,000 | 82 lb |
| 4 | 1,344 | 24,000 | 164 lb |
| 6 | 2,016 | 24,000 | 245 lb |
Gilliam County against the rest of Oregon
Among the 36 Oregon counties with data, Gilliam County is number 17 of 36 counting from the hardest. Across the whole country it is harder than 33% of counties.
Softest in Oregon: Columbia County at 1.4 gpg. Hardest: Malheur County at 17.8 gpg. Closest to Gilliam County: Jefferson County (5.6), Wasco County (5.5), Clackamas County (5.8).