How hard is the water in Lincoln County, OK?
11.1 grains per gallon
A softener will pay its way here.
The median hardness measured in Lincoln County, OK is 190 mg/L as calcium carbonate, which is 11.1 gpg. That is very hard on the USGS scale. It comes from 79 samples at 56 sites between 1990 and 2025, 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 6.2 and 17 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: high (how it is measured).
What to do next
At 11.1 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. Because Lincoln 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 0.2 to 147.2 gpg
The softest single sample on record in Lincoln County was 3.9 mg/L and the hardest 2,520 mg/L, a 646-fold gap. The top quarter of sites read above 17 gpg and the bottom quarter below 6.2 gpg. So even here some sites draw water soft enough to need nothing at all.
Wells 11.1 gpg, rivers and lakes 17.3 gpg
79 groundwater samples from 56 wells put the median at 190 mg/L. 718 surface samples from 33 sites put it at 297 mg/L. In Lincoln County the rivers and lakes come out 6.2 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 242 lb of salt a year (7 bags of 40 lb, about $44), 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 $144 a year.
Sizing at 11.1 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 666 | 24,000 | 81 lb |
| 2 | 1,332 | 24,000 | 162 lb |
| 4 | 2,664 | 24,000 | 324 lb |
| 6 | 3,996 | 32,000 | 486 lb |
Lincoln County against the rest of Oklahoma
Among the 77 Oklahoma counties with data, Lincoln County is number 50 of 77 counting from the hardest. Across the whole country it is harder than 55% of counties.
Softest in Oklahoma: McCurtain County at 0.8 gpg. Hardest: Greer County at 125 gpg. Closest to Lincoln County: McIntosh County (11), Hughes County (11.2), Bryan County (10.8).