How hard is the water in Roger Mills County, OK?
29.5 grains per gallon
A softener will pay its way here.
The median hardness measured in Roger Mills County, OK is 505 mg/L as calcium carbonate, which is 29.5 gpg. That is very hard on the USGS scale. It comes from 222 samples at 26 sites between 1992 and 2025, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 16.3 and 68.1 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 29.5 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.
More on sizing a softener for your household.
From 10.0 to 175.2 gpg
The softest single sample on record in Roger Mills County was 172 mg/L and the hardest 3,000 mg/L, a 17-fold gap. The top quarter of sites read above 68.1 gpg and the bottom quarter below 16.3 gpg.
Wells 10.8 gpg, rivers and lakes 29.5 gpg
1 groundwater samples from 1 wells put the median at 185 mg/L. 221 surface samples from 25 sites put it at 505 mg/L. In Roger Mills County the rivers and lakes come out 18.7 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 40,000-grain unit covers a week between regenerations. Expect about 644 lb of salt a year (17 bags of 40 lb, about $116), 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 $216 a year.
Sizing at 29.5 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,770 | 24,000 | 215 lb |
| 2 | 3,540 | 32,000 | 431 lb |
| 4 | 7,080 | 64,000 | 861 lb |
| 6 | 10,620 | 80,000 | 1,292 lb |
Roger Mills County against the rest of Oklahoma
Among the 77 Oklahoma counties with data, Roger Mills County is number 16 of 77 counting from the hardest. Across the whole country it is harder than 94% of counties.
Softest in Oklahoma: McCurtain County at 0.8 gpg. Hardest: Greer County at 125 gpg. Closest to Roger Mills County: Harper County (28.9), Stephens County (28.7), Blaine County (26.3).