How hard is the water in Grady County, OK?
34.2 grains per gallon
A softener will pay its way here.
The median hardness measured in Grady County, OK is 585 mg/L as calcium carbonate, which is 34.2 gpg. That is very hard on the USGS scale. It comes from 389 samples at 31 sites between 2000 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 24.5 and 44.4 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 34.2 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 16.7 to 93.8 gpg
The softest single sample on record in Grady County was 286.5 mg/L and the hardest 1,605 mg/L, a 6-fold gap. The top quarter of sites read above 44.4 gpg and the bottom quarter below 24.5 gpg.
What a softener would cost to run
For a household of 3, a 48,000-grain unit covers a week between regenerations. Expect about 746 lb of salt a year (19 bags of 40 lb, about $134), 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 $234 a year.
Sizing at 34.2 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 2,052 | 24,000 | 250 lb |
| 2 | 4,104 | 32,000 | 499 lb |
| 4 | 8,208 | 64,000 | 999 lb |
| 6 | 12,312 | twin tank | 1,498 lb |
Grady County against the rest of Oklahoma
Among the 77 Oklahoma counties with data, Grady County is number 14 of 77 counting from the hardest. Across the whole country it is harder than 96% of counties.
Softest in Oklahoma: McCurtain County at 0.8 gpg. Hardest: Greer County at 125 gpg. Closest to Grady County: Alfalfa County (33.5), Kingfisher County (35.8), Roger Mills County (29.5).