State distribution
Hardness across indexed ZIPs
Counts describe published ZIP profiles, not a population-weighted statewide sample.
Soft · 0–60 PPM1
Moderately hard · 61–120 PPM24
Hard · 121–180 PPM19
Very hard · 181+ PPM83
State water index
Ohio water hardness
Search 119 indexed communities and 162 ZIP profiles, then compare the underlying utility, source, distance, and reporting context.
Median regional evidence
234PPM
Very Hard
Indexed range 5.1–433 PPM
- ZIP profiles
- 162
- Cities
- 119
- Matched utilities
- 119
- Counties
- 65
Understanding Ohio
Why local comparisons matter here
Ohio combines Lake Erie and river-supplied cities with glacial and bedrock aquifers across the interior and Appalachian southeast.
In this index, very hard is the largest category, covering 83 of 127 profiles with hardness data. The state median is 234 PPM, but the full indexed range is 5.1–433 PPM.
Evidence coverage
What the current records support
- Hardness estimate
- 78%
- Lead 90th percentile
- 100%
- Copper 90th percentile
- 86%
79
Low-confidence hardness profiles
6
Research-comparison eligible profiles
Reported source water
Utility source mix
- Surface water
- 68
- Groundwater
- 50
- Groundwater influenced by surface water
- 1
Highest medians
Highest eligible city medians
Lowest medians
Lowest eligible city medians
City directory
Explore Ohio by city
Search by city or county, then sort by name, hardness, or ZIP coverage.
119 cities · 162 ZIP profiles
119 cities found
Page 1 of 5
Alliance
Stark County · 1 ZIP
76PPM regional
Single regional valueNo active flag
Amherst
Lorain County · 1 ZIP
175PPM regional
Single regional valueNo active flag
Ashland
Ashland County · 1 ZIP
—
No regional sampleNo active flag
Aurora
Portage County · 1 ZIP
164PPM regional
Single regional valueNo active flag
Avon
Lorain County · 1 ZIP
164PPM regional
Single regional valueNo active flag
Avon Lake
Lorain County · 1 ZIP
164PPM regional
Single regional valueNo active flag
Barnesville
Belmont County · 1 ZIP
340PPM regional
Single regional valueNo active flag
Bellbrook
Greene County · 1 ZIP
391PPM regional
Single regional valueNo active flag
Bellefontaine
Logan County · 1 ZIP
383PPM regional
Single regional valueNo active flag
Bellevue
Huron County · 1 ZIP
224PPM regional
Single regional valueNo active flag
Belpre
Washington County · 1 ZIP
247PPM regional
Single regional valueNo active flag
Berea
Cuyahoga County · 1 ZIP
164PPM regional
Single regional valueNo active flag
Berlin
Holmes County · 2 ZIPs
279PPM regional
Regional range 235.5–322No active flag
Bowling Green
Wood County · 2 ZIPs
234PPM regional
Single regional valueNo active flag
Brilliant
Jefferson County · 1 ZIP
240PPM regional
Single regional valueNo active flag
Brookville
Montgomery County · 1 ZIP
336PPM regional
Single regional valueNo active flag
Bryan
Williams County · 1 ZIP
292PPM regional
Single regional valueNo active flag
Bucyrus
Crawford County · 1 ZIP
—
No regional sampleNo active flag
Byesville
Guernsey County · 1 ZIP
298PPM regional
Single regional valueNo active flag
Canal Fulton
Stark County · 1 ZIP
134PPM regional
Single regional valueNo active flag
Canfield
Mahoning County · 1 ZIP
96PPM regional
Single regional valueNo active flag
Chardon
Geauga County · 1 ZIP
5PPM regional
Single regional valueNo active flag
Chauncey
Athens County · 1 ZIP
267PPM regional
Single regional valueNo active flag
Chillicothe
Ross County · 1 ZIP
329PPM regional
Single regional valueNo active flag
County comparison
Highest regional-evidence county medians
| County | Median | Range | ZIP profiles |
|---|---|---|---|
| Pickaway County | 414 PPM | 414–414 | 1 |
| Champaign County | 394 PPM | 394–394 | 1 |
| Clark County | 394 PPM | 389–394.5 | 7 |
| Pike County | 393 PPM | 392.5–392.5 | 1 |
| Greene County | 391 PPM | 390.5–390.5 | 2 |
| Logan County | 383 PPM | 383–383 | 1 |
| Butler County | 358 PPM | 358–358 | 2 |
| Montgomery County | 358 PPM | 336–387 | 6 |
| Auglaize County | 347 PPM | 347–347 | 1 |
| Clermont County | 345 PPM | 337–352 | 2 |
| Hamilton County | 344 PPM | 344–344 | 2 |
| Belmont County | 340 PPM | 339.5–339.5 | 1 |