Well water hardness in Wisconsin
Across 28 counties of Wisconsin, the median well sampled by the USGS has 13.9 gpg of hardness. Counties range from 1.2 gpg (Douglas County) to 28 gpg (Winnebago County).
Millions of American households drink water from their own well. No utility tests that water and no water quality report covers it. These pages summarise the hardness the U.S. Geological Survey measured in wells county by county, so you know what to expect before you test your own well.
Counties, hardest first
| gpg | mg/L | wells | ||
|---|---|---|---|---|
| Winnebago County | 28 | 480 | 11 | very hard |
| Fond du Lac County | 27.2 | 466 | 12 | very hard |
| Washington County | 22.4 | 383 | 13 | very hard |
| Waukesha County | 22.1 | 378 | 39 | very hard |
| Walworth County | 21.1 | 361 | 15 | very hard |
| Sheboygan County | 20.9 | 357 | 39 | very hard |
| Outagamie County | 20.2 | 346 | 16 | very hard |
| Dane County | 19.6 | 335 | 24 | very hard |
| Rock County | 19 | 326 | 17 | very hard |
| Racine County | 16.9 | 290 | 31 | very hard |
| Waupaca County | 16.4 | 280 | 16 | very hard |
| Portage County | 16.2 | 277 | 56 | very hard |
| Brown County | 15.8 | 270 | 87 | very hard |
| Kenosha County | 14.7 | 251 | 22 | very hard |
| Marquette County | 13.1 | 225 | 17 | very hard |
| Waushara County | 12.5 | 214 | 16 | very hard |
| Oconto County | 12.4 | 213 | 10 | very hard |
| Marinette County | 11.9 | 203 | 13 | very hard |
| Shawano County | 11.7 | 200 | 87 | very hard |
| Menominee County | 9.8 | 169 | 74 | hard |
| Langlade County | 8.2 | 140 | 59 | hard |
| Forest County | 7.6 | 130 | 31 | hard |
| Wood County | 6.4 | 110 | 142 | moderately hard |
| Ashland County | 5.4 | 93 | 40 | moderately hard |
| Burnett County | 4.9 | 84 | 47 | moderately hard |
| Vilas County | 1.8 | 31 | 122 | soft |
| Bayfield County | 1.3 | 23 | 47 | soft |
| Douglas County | 1.2 | 20 | 50 | soft |
Counties with fewer than 10 sampled wells, or a median outside 5–500 mg/L, are not shown until the figure is reviewed.
Wisconsin: tap water hardness by city → · Well water hardness by state and county →