Water hardness in Hamilton
7.6 gpg hard
Tap water in Hamilton is hard: 7.6 gpg (130 mg/L · 7.3 °dH · 13 °fH).
Source: City of Hamilton (Ohio), 2025 Water Quality Report (CCR, reporting year 2025) (2025) · data checked 2026-10-23
Hamilton pumps all of its water from wells in the Great Miami Buried Valley Aquifer and treats it at lime-softening plants, which is why the finished water sits at 130 mg/L CaCO₃ rather than the much higher raw-water level. That is hard water, though softer than the raw aquifer. Expect some scale in kettles and heaters.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 7.6 gpg |
|---|---|
| Calcium (mg/L) | 21 |
| Magnesium (mg/L) | 23 |
| Utility | City of Hamilton Utilities (Water Production; lime-softened groundwater, North and South plants) |
How Hamilton compares
- Tap water in Hamilton is 16 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 826 of 1372 in the United States (1 = hardest); 39 % of these cities have softer water.
- In Ohio it is number 7 of 31 cities; the regional median is 7 gpg.
- Nearest city with clearly harder water: Richmond, 56 km away (17.1 gpg).
Ranking of the hardest and softest water in the United States →
What it means at home
- Fast scale on taps, shower screens and kettle; white spots on glassware.
- Water heater: efficiency loss and element failures within years if unprotected.
- Dry skin and dull hair after showering are common.
- Softener recommended; jug or reverse osmosis for drinking.
How much salt will you use for softening?
Recommended, especially with a heater or boiler: scale cuts efficiency and shortens its life.
Descale a coffee machine or kettle about every 2 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Hamilton
| Brand | Setting for this water |
|---|---|
| Bosch | H01 |
| Miele | 7 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| Hoover | S1 |
| LG | H2 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is Hamilton water hard or soft?
It is hard: 130 mg/L as CaCO₃ (7.6 gpg, 7.3 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Hamilton safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
How many grains per gallon is Hamilton water?
7.6 gpg, equal to 7.3 °dH, 13 °fH or 130 mg/L calcium carbonate.
What dishwasher salt setting should I use in Hamilton?
For 130 mg/L (7.3 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Hamilton?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: City of Hamilton (Ohio), 2025 Water Quality Report (CCR, reporting year 2025) (2025). Method: figure published by the water supplier. City of Hamilton (Ohio), 2025 Water Quality Report (CCR, reporting year 2025) · Outdated figure? Tell us