How hard is the water in Noble County, OK?
19.6 grains per gallon
A softener will pay its way here.
The median hardness measured in Noble County, OK is 335 mg/L as calcium carbonate, which is 19.6 gpg. That is very hard on the USGS scale. It comes from 492 samples at 34 sites between 2007 and 2024, drawn from every sampling site in the county, wells and surface water together.
How much it varies here
Half the sites came in between 15 and 21.9 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 19.6 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 2.0 to 36.8 gpg
The softest single sample on record in Noble County was 34.8 mg/L and the hardest 630 mg/L, an 18-fold gap. The top quarter of sites read above 21.9 gpg and the bottom quarter below 15 gpg. So even here some sites draw water soft enough to need nothing at all.
What a softener would cost to run
For a household of 3, a 32,000-grain unit covers a week between regenerations. Expect about 427 lb of salt a year (11 bags of 40 lb, about $77), 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 $177 a year.
Sizing at 19.6 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,176 | 24,000 | 143 lb |
| 2 | 2,352 | 24,000 | 286 lb |
| 4 | 4,704 | 40,000 | 572 lb |
| 6 | 7,056 | 64,000 | 858 lb |
Noble County against the rest of Oklahoma
Among the 77 Oklahoma counties with data, Noble County is number 26 of 77 counting from the hardest. Across the whole country it is harder than 83% of counties.
Softest in Oklahoma: McCurtain County at 0.8 gpg. Hardest: Greer County at 125 gpg. Closest to Noble County: Murray County (19.2), Johnston County (20.3), Carter County (18.7).