Hard water in Monroe, WI
Reported by Monroe Waterworks · August 2022
- WI typical
- 170 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 32k grain
- Data
- Utility report
The water in Monroe carries roughly 261 mg/L of dissolved calcium and magnesium, or 15.2 grains per gallon. That is very hard water. The number comes from Monroe Waterworks, dated August 2022.
Monroe sits 91 mg/L above the typical Wisconsin figure of 170. None of the 10 nearest cities we track has softer water. The range nearby runs from 270 mg/L in Fitchburg to 420 in Monona.
What 261 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 261 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 × 15.2 gpg = 3,431 grains a day. A 32,000-grain unit regenerates about every 9 days.
EPA record for Monroe's water system
No health-based violations since 2016
Serves about 10,780 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 Monroe water hard?
Yes. It measures about 261 mg/L (15.2 grains per gallon), which the USGS classes as very hard.
What is the water hardness in Monroe in grains per gallon?
About 15.2 gpg. One grain per gallon equals 17.1 mg/L, so 261 mg/L divided by 17.1 gives 15.2.
What size water softener do I need in Monroe?
For 3 people using 75 gallons each per day, 15.2 gpg works out to about 3,431 grains a day. A 32,000-grain softener covers that with a regeneration about every 9 days.
Has the Monroe water system had EPA violations?
EPA records show no health-based violations for Monroe Waterworks since 2016.
Nearby cities
- Oregon283 mg/LVery hard
- Verona360 mg/LVery hard
- Fitchburg270 mg/LVery hard
- Stoughton312 mg/LVery hard
- Beloit333 mg/LVery hard
- Janesville298 mg/LVery hard
- Edgerton291 mg/LVery hard
- McFarland364 mg/LVery hard
- Monona420 mg/LVery hard
- Madison341 mg/LVery hard
Hardness data: TapWaterData US Water Hardness (utility report, August 16, 2022), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.