How hard is the water in Walworth County, WI?
21.6 grains per gallon
A softener will pay its way here.
The median hardness measured in Walworth County, WI is 369 mg/L as calcium carbonate, which is 21.6 gpg. That is very hard on the USGS scale. It comes from 15 samples at 7 sites between 1990 and 2026, 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 21.3 and 23.6 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: medium (how it is measured).
What to do next
At 21.6 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 16.5 to 40.1 gpg
The softest single sample on record in Walworth County was 282 mg/L and the hardest 686 mg/L, a 2-fold gap. The top quarter of sites read above 23.6 gpg and the bottom quarter below 21.3 gpg.
Wells 21.6 gpg, rivers and lakes 14.2 gpg
15 groundwater samples from 7 wells put the median at 369 mg/L. 552 surface samples from 43 sites put it at 243 mg/L. In Walworth County the wells come out 7.4 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 32,000-grain unit covers a week between regenerations. Expect about 471 lb of salt a year (12 bags of 40 lb, about $85), 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 $185 a year.
Sizing at 21.6 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,296 | 24,000 | 158 lb |
| 2 | 2,592 | 24,000 | 315 lb |
| 4 | 5,184 | 40,000 | 631 lb |
| 6 | 7,776 | 64,000 | 946 lb |
Walworth County against the rest of Wisconsin
Among the 72 Wisconsin counties with data, Walworth County is number 8 of 72 counting from the hardest. Across the whole country it is harder than 87% of counties.
Softest in Wisconsin: Vilas County at 1.4 gpg. Hardest: Calumet County at 28.4 gpg. Closest to Walworth County: Ozaukee County (21.6), Outagamie County (21.1), Grant County (21).