How hard is the water in Franklin County, OH?
26.6 grains per gallon
A softener will pay its way here.
The median hardness measured in Franklin County, OH is 455 mg/L as calcium carbonate, which is 26.6 gpg. That is very hard on the USGS scale. It comes from 334 samples at 58 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 23.4 and 33.3 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 26.6 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 14.8 to 50.1 gpg
The softest single sample on record in Franklin County was 253 mg/L and the hardest 857 mg/L, a 3-fold gap. The top quarter of sites read above 33.3 gpg and the bottom quarter below 23.4 gpg.
Wells 26.6 gpg, rivers and lakes 16 gpg
334 groundwater samples from 58 wells put the median at 455.3 mg/L. 1,984 surface samples from 186 sites put it at 273.8 mg/L. In Franklin County the wells come out 10.6 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, a 40,000-grain unit covers a week between regenerations. Expect about 581 lb of salt a year (15 bags of 40 lb, about $105), 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 $205 a year.
Sizing at 26.6 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,596 | 24,000 | 194 lb |
| 2 | 3,192 | 24,000 | 388 lb |
| 4 | 6,384 | 48,000 | 777 lb |
| 6 | 9,576 | 80,000 | 1,165 lb |
Franklin County against the rest of Ohio
Among the 88 Ohio counties with data, Franklin County is number 6 of 88 counting from the hardest. Across the whole country it is harder than 93% of counties.
Softest in Ohio: Scioto County at 5.7 gpg. Hardest: Perry County at 113.3 gpg. Closest to Franklin County: Athens County (26.8), Shelby County (25.5), Madison County (25.1).