How hard is the water in Fairfield, OH?

Tap water hardness
111mg/L
6.5gpg
Moderately hard

Reported by Butler CO. Water District 2 PWS · October 2025

OH typical
113 mg/L
EPA health violations since 2016
0
Softener for 3 people
24k grain
Data
Utility report

Fairfield water measures 111 mg/L (6.5 gpg) of hardness, moderately hard by USGS standards. The number comes from Butler CO. Water District 2 PWS, dated October 2025.

Fairfield on the hardness scale, with nearby cities
060120180240300360+OH typical 113Monroe: 45 mg/LMonroe 45Hamilton: 105 mg/LHamilton 105Beckett Ridge: 111 mg/LBeckett Ridge 111Norwood: 113 mg/LNorwood 113Cincinnati: 113 mg/LCincinnati 113Montgomery: 150 mg/LMontgomery 150The Village of Indian Hill: 150 mg/LThe Village of Indian Hill 150Mason: 280 mg/LMason 280Middletown: 303 mg/LMiddletown 303Oxford: 303 mg/LOxford 303Fairfield 111mg/L as calcium carbonate060120180240300360+OH 113Monroe: 45 mg/LMonroe 45Hamilton: 105 mg/LHamilton 105Beckett Ridge: 111 mg/LBeckett Ri. 111Norwood: 113 mg/LNorwood 113Montgomery: 150 mg/LMontgomery 150Mason: 280 mg/LMason 280111 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

At 111 mg/L, Fairfield is close to the typical Ohio figure of 113 mg/L. Of the 10 nearest cities we track, 2 have softer water and 7 have harder. The range nearby runs from 45 mg/L in Monroe to 303 in Middletown.

What 111 mg/L means at home

You may see faint white spots on glasses and shower doors after the water dries.

Scale builds up slowly. A kettle or coffee maker needs descaling now and then, maybe every few months.

Hardness is not a health problem, and EPA sets no limit for it. It is a matter of scale and soap.

What to do about it

Optional. Plenty of households at this level live with it and descale the kettle now and then.

Water softener

Worth a look if spots on glass bother you, or if your tankless water heater manual asks for softer water.

Carbon filter

Improves taste and removes chlorine. It leaves calcium and magnesium in place.

Softener size for Fairfield

3 people × 75 gallons a day × 6.5 gpg = 1,460 grains a day. A 24,000-grain unit regenerates about every 16 days.

Size it for your household

EPA record for Fairfield's water system

Fairfield City PWS · PWSID OH0900715

No health-based violations since 2016

Serves about 44,907 people from groundwater.

Health-based
0
Monitoring or reporting
0
Open now
0

EPA lists Fairfield City PWS as the system serving Fairfield. The hardness figure above comes from a different system's report, which TapWaterData uses for Fairfield.

Health-based means a contaminant above its legal limit or a missed treatment step. Monitoring and reporting violations are late or missing tests and notices. Source: EPA ECHO, 2026Q3 export, violations with periods starting 2016 or later. Full EPA record.

Questions

Is Fairfield water hard?

Somewhat. It measures about 111 mg/L (6.5 grains per gallon), which the USGS classes as moderately hard.

What is the water hardness in Fairfield in grains per gallon?

About 6.5 gpg. One grain per gallon equals 17.1 mg/L, so 111 mg/L divided by 17.1 gives 6.5.

What size water softener do I need in Fairfield?

For 3 people using 75 gallons each per day, 6.5 gpg works out to about 1,460 grains a day. A 24,000-grain softener covers that with a regeneration about every 16 days.

Has the Fairfield water system had EPA violations?

EPA records show no health-based violations for Fairfield City PWS since 2016.

Nearby cities

All 108 cities in Ohio

Hardness data: TapWaterData US Water Hardness (utility report, October 5, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.