How hard is the water in Montgomery County, OH?
21 grains per gallon
A softener will pay its way here.
The median hardness measured in Montgomery County, OH is 359 mg/L as calcium carbonate, which is 21 gpg. That is very hard on the USGS scale. It comes from 190 samples at 108 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 19.1 and 24 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 21 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 13.8 to 32.5 gpg
The softest single sample on record in Montgomery County was 236 mg/L and the hardest 556 mg/L, a 2-fold gap. The top quarter of sites read above 24 gpg and the bottom quarter below 19.1 gpg.
Wells 21 gpg, rivers and lakes 18.3 gpg
190 groundwater samples from 108 wells put the median at 359 mg/L. 1,217 surface samples from 117 sites put it at 314 mg/L. In Montgomery County the wells come out 2.7 gpg harder. Groundwater sits in contact with rock for years and picks up calcium and magnesium as it goes, so wells usually read harder. The two sources are close, so the county figure should hold whichever one your tap is on.
What a softener would cost to run
For a household of 3, a 32,000-grain unit covers a week between regenerations. Expect about 458 lb of salt a year (12 bags of 40 lb, about $82), 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 $182 a year.
Sizing at 21 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,260 | 24,000 | 153 lb |
| 2 | 2,520 | 24,000 | 307 lb |
| 4 | 5,040 | 40,000 | 613 lb |
| 6 | 7,560 | 64,000 | 920 lb |
Montgomery County against the rest of Ohio
Among the 88 Ohio counties with data, Montgomery County is number 21 of 88 counting from the hardest. Across the whole country it is harder than 86% of counties.
Softest in Ohio: Scioto County at 5.7 gpg. Hardest: Perry County at 113.3 gpg. Closest to Montgomery County: Pike County (20.9), Preble County (20.9), Wayne County (20.9).