How hard is the water in Washita County, OK?
64.8 grains per gallon
A softener will pay its way here.
The median hardness measured in Washita County, OK is 1110 mg/L as calcium carbonate, which is 64.8 gpg. That is very hard on the USGS scale. It comes from 281 samples at 17 sites between 1990 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 53.1 and 104 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 64.8 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 22.0 to 138.7 gpg
The softest single sample on record in Washita County was 376 mg/L and the hardest 2,375 mg/L, a 6-fold gap. The top quarter of sites read above 104 gpg and the bottom quarter below 53.1 gpg.
Wells 95.2 gpg, rivers and lakes 64.8 gpg
4 groundwater samples from 3 wells put the median at 1630 mg/L. 277 surface samples from 14 sites put it at 1110 mg/L. In Washita County the wells come out 30.4 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, the water is harder than a standard single tank handles in a week, so plan on a larger or twin-tank unit. Expect about 1,416 lb of salt a year (36 bags of 40 lb, about $255), 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 $355 a year.
Sizing at 64.8 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 3,888 | 32,000 | 473 lb |
| 2 | 7,776 | 64,000 | 946 lb |
| 4 | 15,552 | twin tank | 1,892 lb |
| 6 | 23,328 | twin tank | 2,838 lb |
Washita County against the rest of Oklahoma
Among the 77 Oklahoma counties with data, Washita County is number 9 of 77 counting from the hardest. Across the whole country it is harder than 99% of counties.
Softest in Oklahoma: McCurtain County at 0.8 gpg. Hardest: Greer County at 125 gpg. Closest to Washita County: Tillman County (52), Kiowa County (43.8), Beckham County (41).