Hard water in Troy, OH
County estimate from 606 water samples in Miami 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 Troy put hardness at about 328 mg/L (19.1 gpg), which would be very hard on the USGS scale. Treat this as a rough guide: it is the median of 606 samples taken across Miami County, mostly wells and streams, not a test of Troy's treated tap water.
At 328 mg/L, Troy is 215 mg/L above the typical Ohio figure of 113. Of the 10 nearest cities we track, 9 have softer water and 1 has harder. The range nearby runs from 49 mg/L in Piqua to 342 in Sidney.
What 328 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 328 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.
3 people × 75 gallons a day × 19.1 gpg = 4,309 grains a day. A 32,000-grain unit regenerates about every 7 days.
EPA record for Troy's water system
No health-based violations since 2016
Serves about 26,305 people from groundwater.
- Health-based
- 0
- Monitoring or reporting
- 2
- Open now
- 0
EPA lists this system as serving Troy.
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 Troy water hard?
Yes. It measures about 328 mg/L (19.1 grains per gallon), which the USGS classes as very hard.
What is the water hardness in Troy in grains per gallon?
About 19.1 gpg. One grain per gallon equals 17.1 mg/L, so 328 mg/L divided by 17.1 gives 19.1.
What size water softener do I need in Troy?
For 3 people using 75 gallons each per day, 19.1 gpg works out to about 4,309 grains a day. A 32,000-grain softener covers that with a regeneration about every 7 days.
Has the Troy water system had EPA violations?
EPA records show no health-based violations for Troy City PWS since 2016. There were also 2 monitoring or reporting violations, which are about late or missing tests and notices.
Nearby cities
- Piqua49 mg/LSoft
- Vandalia155 mg/LHard
- Englewood155 mg/LHard
- Clayton155 mg/LHard
- Huber Heights155 mg/LHard
- Shiloh155 mg/LHard
- Sidney342 mg/LVery hard
- Dayton147 mg/LHard
- Trotwood147 mg/LHard
- Riverside149 mg/LHard
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.