State distribution
Hardness across indexed ZIPs
Counts describe published ZIP profiles, not a population-weighted statewide sample.
Soft · 0–60 PPM0
Moderately hard · 61–120 PPM9
Hard · 121–180 PPM18
Very hard · 181+ PPM291
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 regional evidence
278PPM
Very Hard
Indexed range 69–824 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 291 of 318 profiles with hardness data. The state median is 278 PPM, but the full indexed range is 69–824 PPM.
Evidence coverage
What the current records support
- Hardness estimate
- 57%
- Lead 90th percentile
- 99%
- Copper 90th percentile
- 23%
135
Low-confidence hardness profiles
101
Research-comparison eligible profiles
Reported source water
Utility source mix
- Groundwater
- 752
- Surface water
- 46
Highest medians
Highest eligible city medians
- 1. Richfield518 PPM
Lowest medians
Lowest eligible city medians
- 1. Richfield518 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
—
No regional sampleNo active flag
Abrams
Oconto County · 1 ZIP
118PPM regional
Single regional valueNo active flag
Adams
Adams County · 1 ZIP
285PPM regional
Single regional valueNo active flag
Albany
Green County · 1 ZIP
—
No regional sampleNo active flag
Algoma
Kewaunee County · 1 ZIP
—
No regional sampleNo active flag
Allenton
Washington County · 1 ZIP
446PPM regional
Single regional valueNo active flag
Allouez
Brown County · 2 ZIPs
254PPM regional
Single regional valueNo active flag
Alma
Buffalo County · 1 ZIP
—
No regional sampleNo active flag
Alma Center
Jackson County · 1 ZIP
—
No regional sampleNo active flag
Almena
Barron County · 1 ZIP
191PPM regional
Single regional valueNo active flag
Altoona
Eau Claire County · 1 ZIP
—
No regional sample1 active record
Amery
Polk County · 1 ZIP
225PPM regional
Single regional value1 active record
Amherst
Portage County · 1 ZIP
307PPM regional
Single regional valueNo active flag
Antigo
Langlade County · 1 ZIP
257PPM regional
Single regional value1 active record
Appleton
Outagamie County · 4 ZIPs
275PPM regional
Regional range 236–433No active flag
Arcadia
Trempealeau County · 1 ZIP
—
No regional sampleNo active flag
Arena
Iowa County · 1 ZIP
283PPM regional
Single regional valueNo active flag
Argyle
Lafayette County · 1 ZIP
—
No regional sampleNo active flag
Arlington
Columbia County · 1 ZIP
220PPM regional
Single regional valueNo active flag
Ashland
Ashland County · 1 ZIP
74PPM regional
Single regional valueNo active flag
Athens
Marathon County · 1 ZIP
—
No regional sampleNo active flag
Auburndale
Wood County · 1 ZIP
—
No regional sampleNo active flag
Augusta
Eau Claire County · 1 ZIP
—
No regional sampleNo active flag
Avoca
Iowa County · 1 ZIP
283PPM regional
Single regional valueNo active flag
County comparison
Highest regional-evidence county medians
| County | Median | Range | ZIP profiles |
|---|---|---|---|
| Washington County | 518 PPM | 421–529 | 11 |
| Waukesha County | 518 PPM | 244–540 | 22 |
| Jefferson County | 512 PPM | 494–549 | 7 |
| Dodge County | 467 PPM | 421–518 | 13 |
| Calumet County | 433 PPM | 433–433 | 7 |
| Ozaukee County | 421 PPM | 234–518 | 8 |
| Fond Du Lac County | 417 PPM | 135–421 | 10 |
| Sheboygan County | 417 PPM | 398–421 | 10 |
| Manitowoc County | 398 PPM | 398–398 | 10 |
| Walworth County | 396 PPM | 390–824 | 9 |
| Crawford County | 337 PPM | 337–337 | 6 |
| Vernon County | 337 PPM | 337–337 | 10 |