Hard water in Grafton, WI
Reported by Grafton Waterworks · November 2023
- WI typical
- 170 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 48k grain
- Data
- Utility report
The water in Grafton carries roughly 370 mg/L of dissolved calcium and magnesium, or 21.6 grains per gallon. That is very hard water. The number comes from Grafton Waterworks, dated November 2023.
Grafton sits 200 mg/L above the typical Wisconsin figure of 170. Of the 10 nearest cities we track, 7 have softer water and 3 have harder. The range nearby runs from 129 mg/L in Whitefish Bay to 440 in Mequon.
What 370 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 370 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 × 21.6 gpg = 4,869 grains a day. A 48,000-grain unit regenerates about every 9 days.
EPA record for Grafton's water system
No health-based violations since 2016
Serves about 12,269 people from groundwater.
- Health-based
- 0
- Monitoring or reporting
- 0
- Open now
- 0
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 Grafton water hard?
Yes. It measures about 370 mg/L (21.6 grains per gallon), which the USGS classes as very hard.
What is the water hardness in Grafton in grains per gallon?
About 21.6 gpg. One grain per gallon equals 17.1 mg/L, so 370 mg/L divided by 17.1 gives 21.6.
What size water softener do I need in Grafton?
For 3 people using 75 gallons each per day, 21.6 gpg works out to about 4,869 grains a day. A 48,000-grain softener covers that with a regeneration about every 9 days.
Has the Grafton water system had EPA violations?
EPA records show no health-based violations for Grafton Waterworks since 2016.
Nearby cities
- Cedarburg400 mg/LVery hard
- Mequon440 mg/LVery hard
- Germantown422 mg/LVery hard
- Jackson352 mg/LVery hard
- Fox Point133 mg/LHard
- Glendale134 mg/LHard
- West Bend340 mg/LVery hard
- Menomonee Falls174 mg/LHard
- Whitefish Bay129 mg/LHard
- Shorewood130 mg/LHard
Hardness data: TapWaterData US Water Hardness (utility report, November 28, 2023), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.