Water hardness by state
How hard is the water in Ohio?
Tap water in Ohio averages 21.1 grains per gallon (360 ppm calcium carbonate). That number determines how fast limescale coats your water heater, shower glass and appliances.
Sur la base de 91 mesures issues de 91 points de surveillance, 2019-07 → 2023-08.
Dureté de l’eau par comté — Ohio
Médianes des mesures relevées dans chaque comté. La dureté varie beaucoup plus à l’intérieur d’un État qu’entre États voisins : c’est de là que vient réellement votre valeur.
| Comté | gpg | mg/L | Fourchette (mg/L) | Classification |
|---|---|---|---|---|
| Butler County | 20.9 | 358 | 135–406 | Very hard water |
| Clark County | 23 | 394 | 340–424 | Very hard water |
| Champaign County | 22.7 | 388 | 2–416 | Very hard water |
| Greene County | 22.8 | 390 | 243–440 | Very hard water |
| Montgomery County | 23.1 | 395 | 342–439 | Very hard water |
| Hamilton County | 20.6 | 352 | 151–360 | Very hard water |
La fourchette correspond aux 10e-90e centiles des mesures locales. Les comtés comptant moins de cinq mesures sont omis plutôt qu’estimés.
What 21.1 gpg means in Ohio
This is very hard water — among the harshest levels measured. Scale attacks water heaters, dishwashers and pipes fast, shortening appliance lifespan and inflating energy bills. Protection is essential.
What it does to your home
Water heater: even a thin layer of scale insulates the heating element and drives energy use up.
Appliances: dishwashers, washing machines and coffee makers scale up and fail years early.
Fixtures and skin: white spots on faucets and glass, dry skin and dull hair after every shower.
Comment cette valeur a été obtenue
Median of the site-level medians at 91 groundwater monitoring sites (wells and springs — the sources most US public systems draw from) in the USGS National Water Information System (91 individual measurements, 2019-07 → 2023-08). Each site is collapsed to one value first so that a heavily sampled location cannot skew the state figure; the range shown is the 10th-90th percentile across sites. This describes the raw water resource, not a specific municipal tap after treatment.
Water Quality Portal — USGS National Water Information System (NWIS), characteristic "Hardness, Ca, Mg"Statewide average — hardness varies by utility and season. Always verify with your local water quality report.
Frequently asked questions — Ohio
Is 21.1 gpg considered hard water?
On the US scale, 0–3.5 gpg is soft, 3.5–7 gpg moderately hard, 7–10.5 gpg hard and above 10.5 gpg very hard. At 21.1 gpg (360 ppm), water in Ohio is classified as Very hard water.
Does Ohio have a limescale problem?
Water in Ohio averages 21.1 gpg — Very hard water. The harder the water, the faster calcium carbonate deposits build up in water heaters, appliances and pipes. Below 3.5 gpg the risk is minimal; above 7 gpg scale becomes a running cost.
How do I find the exact water hardness at my address in Ohio?
Check your utility's annual water quality report (Consumer Confidence Report) or your water bill, or use our free interactive hardness map. Hardness can vary widely between neighboring utilities in Ohio.
Do I need a salt-based water softener at 21.1 gpg?
Not necessarily. Salt softeners add sodium to your water and need constant refills. LIMPEO treats limescale with an electromagnetic field — no salt, no chemicals, no maintenance — and keeps healthy minerals in your drinking water.