Hard water in Marysville, OH
County estimate from 1,063 water samples in Union 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 Marysville put hardness at about 316 mg/L (18.5 gpg), which would be very hard on the USGS scale. Treat this as a rough guide: it is the median of 1,063 samples taken across Union County, mostly wells and streams, not a test of Marysville's treated tap water. One more reason for caution: EPA lists Marysville's water system as using surface water, which is often softer than the wells behind the county figure.
Marysville sits 203 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 94 mg/L in Powell to 124 in Westerville.
What 316 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 316 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 × 18.5 gpg = 4,158 grains a day. A 32,000-grain unit regenerates about every 7 days.
EPA record for Marysville's water system
No health-based violations since 2016
Serves about 25,571 people from surface water.
- Health-based
- 0
- Monitoring or reporting
- 2
- Open now
- 1
EPA lists this system as serving Marysville.
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 Marysville water hard?
Yes. It measures about 316 mg/L (18.5 grains per gallon), which the USGS classes as very hard.
What is the water hardness in Marysville in grains per gallon?
About 18.5 gpg. One grain per gallon equals 17.1 mg/L, so 316 mg/L divided by 17.1 gives 18.5.
What size water softener do I need in Marysville?
For 3 people using 75 gallons each per day, 18.5 gpg works out to about 4,158 grains a day. A 32,000-grain softener covers that with a regeneration about every 7 days.
Has the Marysville water system had EPA violations?
EPA records show no health-based violations for Marysville City PWS since 2016. There were also 2 monitoring or reporting violations, which are about late or missing tests and notices.
Nearby cities
- Dublin97 mg/LModerately hard
- Powell94 mg/LModerately hard
- Delaware94 mg/LModerately hard
- Hilliard97 mg/LModerately hard
- Worthington97 mg/LModerately hard
- Upper Arlington97 mg/LModerately hard
- Lincoln Village97 mg/LModerately hard
- Grandview Heights97 mg/LModerately hard
- Westerville124 mg/LHard
- Columbus97 mg/LModerately hard
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.