How hard is the water in Jefferson County, WI?
16.1 grains per gallon
A softener will pay its way here.
The median hardness measured in Jefferson County, WI is 275 mg/L as calcium carbonate, which is 16.1 gpg. That is very hard on the USGS scale. It comes from 51 samples at 12 sites between 1990 and 2014, 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 17.8 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 16.1 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 12.9 to 32.1 gpg
The softest single sample on record in Jefferson County was 220 mg/L and the hardest 550 mg/L, a 3-fold gap. The top quarter of sites read above 17.8 gpg and the bottom quarter below 15 gpg.
Wells 15.9 gpg, rivers and lakes 16.1 gpg
2 groundwater samples from 2 wells put the median at 273 mg/L. 49 surface samples from 10 sites put it at 275 mg/L. In Jefferson County the rivers and lakes come out 0.2 gpg harder. Here the surface water reads harder than the wells, which often points to streams fed by limestone springs or irrigation return flow. 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 24,000-grain unit covers a week between regenerations. Expect about 351 lb of salt a year (9 bags of 40 lb, about $63), 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 $163 a year.
Sizing at 16.1 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 966 | 24,000 | 118 lb |
| 2 | 1,932 | 24,000 | 235 lb |
| 4 | 3,864 | 32,000 | 470 lb |
| 6 | 5,796 | 48,000 | 705 lb |
Jefferson County against the rest of Wisconsin
Among the 72 Wisconsin counties with data, Jefferson County is number 24 of 72 counting from the hardest. Across the whole country it is harder than 73% of counties.
Softest in Wisconsin: Vilas County at 1.4 gpg. Hardest: Calumet County at 28.4 gpg. Closest to Jefferson County: Door County (16.4), Portage County (16.4), Oconto County (15.5).