Hard water in Oxford, OH

Tap water hardness
303mg/L
17.7gpg
Very hardCounty estimate

County estimate from 1,123 water samples in Butler County · July 2026

OH typical
113 mg/L
EPA health violations since 2016
0
Softener for 3 people
32k grain
Data
County estimate

Water samples from around Oxford put hardness at about 303 mg/L (17.7 gpg), which would be very hard on the USGS scale. Treat this as a rough guide: it is the median of 1,123 samples taken across Butler County, mostly wells and streams, not a test of Oxford's treated tap water.

Oxford on the hardness scale, with nearby cities
060120180240300360+OH typical 113Monroe: 45 mg/LMonroe 45Hamilton: 105 mg/LHamilton 105Fairfield: 111 mg/LFairfield 111Beckett Ridge: 111 mg/LBeckett Ridge 111Cincinnati: 113 mg/LCincinnati 113Miamisburg: 142 mg/LMiamisburg 142West Carrollton: 147 mg/LWest Carrollton 147Montgomery: 150 mg/LMontgomery 150Mason: 280 mg/LMason 280Middletown: 303 mg/LMiddletown 303Oxford 303mg/L as calcium carbonate060120180240300360+OH 113Monroe: 45 mg/LMonroe 45Hamilton: 105 mg/LHamilton 105Fairfield: 111 mg/LFairfield 111Beckett Ridge: 111 mg/LBeckett Ri. 111Mason: 280 mg/LMason 280Middletown: 303 mg/LMiddletown 303303 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 303 mg/L, Oxford is 190 mg/L above the typical Ohio figure of 113. None of the 10 nearest cities we track has harder water. The range nearby runs from 45 mg/L in Monroe to 303 in Middletown.

What 303 mg/L means at home

Scale forms fast here. Kettles and coffee makers need regular descaling, and showerheads clog unless you clean them.

Tank water heaters collect mineral sediment that insulates the water from the burner, so flushing the tank matters more than usual.

Dishes and glass shower doors spot easily. Soap scum and a dull film on hair or laundry are common complaints.

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

At 303 mg/L most of the trouble is scale, and only a few things deal with it.

Ion-exchange water softener

The standard whole-house fix. It swaps calcium and magnesium for sodium or potassium and needs salt plus a drain. Size it with the calculator below.

Salt-free conditioner

No salt and no drain line. It changes how minerals form scale instead of removing them, so water still tests hard.

Reverse osmosis or carbon filter

Under-sink reverse osmosis removes minerals from drinking water only. Plain carbon filters improve taste but do not soften.

Softener size for Oxford

3 people × 75 gallons a day × 17.7 gpg = 3,987 grains a day. A 32,000-grain unit regenerates about every 8 days.

Size it for your household

EPA record for Oxford's water system

Oxford City PWS · PWSID OH0902312

No health-based violations since 2016

Serves about 24,000 people from groundwater.

Health-based
0
Monitoring or reporting
0
Open now
0

EPA lists this system as serving Oxford.

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 Oxford water hard?

Yes. It measures about 303 mg/L (17.7 grains per gallon), which the USGS classes as very hard.

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

About 17.7 gpg. One grain per gallon equals 17.1 mg/L, so 303 mg/L divided by 17.1 gives 17.7.

What size water softener do I need in Oxford?

For 3 people using 75 gallons each per day, 17.7 gpg works out to about 3,987 grains a day. A 32,000-grain softener covers that with a regeneration about every 8 days.

Has the Oxford water system had EPA violations?

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

Nearby cities

All 108 cities in Ohio

Hardness data: TapWaterData US Water Hardness (county estimate, July 4, 2026), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.