Water hardness in Columbus (Ohio)
7.2 gpg hard
Tap water in Columbus (Ohio) is hard: 7.2 gpg (123 mg/L · 6.9 °dH · 12.3 °fH).
Source: City of Columbus 2025 Consumer Confidence Report, Hardness by treatment plant (2025) · data checked 2026-10-19
Range across supply zones: 85–132 mg/L.
3 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| gpg | mg/L | ||
|---|---|---|---|
| Dublin Road Water Plant | 7.3 | 125 | hard |
| Hap Cremean Water Plant | 5.7 | 98 | moderately hard |
| Parsons Avenue Water Plant | 7.2 | 123 | hard |
The Columbus Division of Water reports hardness by treatment plant in its 2025 report. Dublin Road averages 125 mg/L, Parsons Avenue (wells) 123 mg/L and Hap Cremean 98 mg/L, which is the softest. The page shows the median of 123 mg/L (7.2 gpg) within a range of 85 to 132 mg/L. The city also softens its water to a set target, so the figures are for treated water as delivered.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 7.2 gpg |
|---|---|
| Utility | City of Columbus Division of Water |
How Columbus (Ohio) compares
- Tap water in Columbus (Ohio) is 21 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 875 of 1372 in the United States (1 = hardest); 36 % of these cities have softer water.
- In Ohio it is number 9 of 31 cities; the regional median is 7 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 Columbus
| 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 Columbus (Ohio) water hard or soft?
It is hard: 123 mg/L as CaCO₃ (7.2 gpg, 6.9 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Columbus (Ohio) 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 Columbus (Ohio) water?
7.2 gpg, equal to 6.9 °dH, 12.3 °fH or 123 mg/L calcium carbonate.
What dishwasher salt setting should I use in Columbus (Ohio)?
For 123 mg/L (6.9 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Columbus (Ohio)?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: City of Columbus 2025 Consumer Confidence Report, Hardness by treatment plant (2025). Method: own measurement. City of Columbus 2025 Consumer Confidence Report, Hardness by treatment plant · Outdated figure? Tell us