State distribution
Hardness across indexed ZIPs
Counts describe published ZIP profiles, not a population-weighted statewide sample.
Soft · 0–60 PPM11
Moderately hard · 61–120 PPM9
Hard · 121–180 PPM11
Very hard · 181+ PPM525
State water index
Wisconsin water hardness
Search 479 indexed communities and 556 ZIP profiles, then compare the underlying utility, source, distance, and reporting context.
Median indexed hardness
288PPM
Very Hard
Indexed range 41.3–467 PPM
- ZIP profiles
- 556
- Cities
- 479
- Matched utilities
- 798
- Counties
- 71
Understanding Wisconsin
Why local comparisons matter here
Wisconsin includes Great Lakes supplies, glacial sand-and-gravel aquifers, and carbonate or sandstone bedrock systems across the state.
In this index, very hard is the largest category, covering 525 of 556 profiles with hardness data. The state median is 288 PPM, but the full indexed range is 41.3–467 PPM.
Evidence coverage
What the current records support
- Hardness estimate
- 100%
- Lead 90th percentile
- 99%
- Copper 90th percentile
- 23%
231
Low-confidence hardness profiles
230
Nearest site more than 25 miles away
Reported source water
Utility source mix
- Groundwater
- 752
- Surface water
- 46
Highest medians
Hardest indexed cities
- 1. Cedar Grove467 PPM
- 2. Oostburg450 PPM
- 3. Belgium449 PPM
- 4. Random Lake432 PPM
- 5. Saukville430 PPM
Lowest medians
Softest indexed cities
- 1. Winter41 PPM
- 2. Park Falls41 PPM
- 3. Montreal41 PPM
- 4. Iron Belt41 PPM
- 5. Hurley41 PPM
City directory
Explore Wisconsin by city
Search by city or county, then sort by name, hardness, or ZIP coverage.
479 cities · 556 ZIP profiles
479 cities found
Page 1 of 20
Abbotsford
Marathon County · 1 ZIP
293PPM
Single indexed valueNo active flag
Abrams
Oconto County · 1 ZIP
257PPM
Single indexed valueNo active flag
Adams
Adams County · 1 ZIP
290PPM
Single indexed valueNo active flag
Albany
Green County · 1 ZIP
395PPM
Single indexed valueNo active flag
Algoma
Kewaunee County · 1 ZIP
222PPM
Single indexed valueNo active flag
Allenton
Washington County · 1 ZIP
396PPM
Single indexed valueNo active flag
Allouez
Brown County · 2 ZIPs
234PPM
Single indexed valueNo active flag
Alma
Buffalo County · 1 ZIP
284PPM
Single indexed valueNo active flag
Alma Center
Jackson County · 1 ZIP
254PPM
Single indexed valueNo active flag
Almena
Barron County · 1 ZIP
333PPM
Single indexed valueNo active flag
Altoona
Eau Claire County · 1 ZIP
261PPM
Single indexed value1 active record
Amery
Polk County · 1 ZIP
320PPM
Single indexed value1 active record
Amherst
Portage County · 1 ZIP
286PPM
Single indexed valueNo active flag
Antigo
Langlade County · 1 ZIP
255PPM
Single indexed value1 active record
Appleton
Outagamie County · 4 ZIPs
236PPM
Range 235–289No active flag
Arcadia
Trempealeau County · 1 ZIP
317PPM
Single indexed valueNo active flag
Arena
Iowa County · 1 ZIP
284PPM
Single indexed valueNo active flag
Argyle
Lafayette County · 1 ZIP
339PPM
Single indexed valueNo active flag
Arlington
Columbia County · 1 ZIP
347PPM
Single indexed valueNo active flag
Ashland
Ashland County · 1 ZIP
70PPM
Single indexed valueNo active flag
Athens
Marathon County · 1 ZIP
288PPM
Single indexed valueNo active flag
Auburndale
Wood County · 1 ZIP
289PPM
Single indexed valueNo active flag
Augusta
Eau Claire County · 1 ZIP
225PPM
Single indexed valueNo active flag
Avoca
Iowa County · 1 ZIP
278PPM
Single indexed valueNo active flag
County comparison
Highest indexed county medians
| County | Median | Range | ZIP profiles |
|---|---|---|---|
| Ozaukee County | 425 PPM | 242–448.5 | 8 |
| Waukesha County | 416 PPM | 242–417 | 22 |
| Washington County | 411 PPM | 393–427 | 11 |
| Walworth County | 408 PPM | 405–414 | 9 |
| Rock County | 396 PPM | 396–405 | 11 |
| Jefferson County | 394 PPM | 394–417 | 7 |
| Dane County | 377 PPM | 283.5–394 | 34 |
| Dodge County | 375 PPM | 329.5–398 | 13 |
| Green County | 372 PPM | 357–395 | 6 |
| Sheboygan County | 359 PPM | 236–467 | 10 |
| Columbia County | 336 PPM | 329.5–370 | 11 |
| Fond Du Lac County | 333 PPM | 319–358 | 10 |