How hard is the water in Logan County, OK?
13.1 grains per gallon
A softener will pay its way here.
The median hardness measured in Logan County, OK is 225 mg/L as calcium carbonate, which is 13.1 gpg. That is very hard on the USGS scale. It comes from 24 samples at 8 sites between 1990 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 5.5 and 16.4 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: medium (how it is measured).
What to do next
At 13.1 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 Logan 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 0.5 to 36.5 gpg
The softest single sample on record in Logan County was 8.8 mg/L and the hardest 624 mg/L, a 71-fold gap. The top quarter of sites read above 16.4 gpg and the bottom quarter below 5.5 gpg. So even here some sites draw water soft enough to need nothing at all.
Wells 13.1 gpg, rivers and lakes 22.4 gpg
24 groundwater samples from 8 wells put the median at 224.5 mg/L. 412 surface samples from 24 sites put it at 384 mg/L. In Logan County the rivers and lakes come out 9.3 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 286 lb of salt a year (8 bags of 40 lb, about $52), 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 $152 a year.
Sizing at 13.1 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 786 | 24,000 | 96 lb |
| 2 | 1,572 | 24,000 | 191 lb |
| 4 | 3,144 | 24,000 | 383 lb |
| 6 | 4,716 | 40,000 | 574 lb |
Logan County against the rest of Oklahoma
Among the 77 Oklahoma counties with data, Logan County is number 40 of 77 counting from the hardest. Across the whole country it is harder than 63% of counties.
Softest in Oklahoma: McCurtain County at 0.8 gpg. Hardest: Greer County at 125 gpg. Closest to Logan County: Seminole County (13.2), Cimarron County (12.9), Pawnee County (12.9).