Hard water in Stoughton, WI
Reported by Stoughton Waterworks · January 2025
- WI typical
- 170 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 32k grain
- Data
- Utility report
The water in Stoughton carries roughly 312 mg/L of dissolved calcium and magnesium, or 18.2 grains per gallon. That is very hard water. The number comes from Stoughton Waterworks, dated January 2025.
Stoughton sits 142 mg/L above the typical Wisconsin figure of 170. Of the 10 nearest cities we track, 3 have softer water and 7 have harder. The range nearby runs from 270 mg/L in Fitchburg to 420 in Monona.
What 312 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 312 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 × 18.2 gpg = 4,106 grains a day. A 32,000-grain unit regenerates about every 7 days.
EPA record for Stoughton's water system
No health-based violations since 2016
Serves about 13,078 people from groundwater.
- Health-based
- 0
- Monitoring or reporting
- 1
- 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 Stoughton water hard?
Yes. It measures about 312 mg/L (18.2 grains per gallon), which the USGS classes as very hard.
What is the water hardness in Stoughton in grains per gallon?
About 18.2 gpg. One grain per gallon equals 17.1 mg/L, so 312 mg/L divided by 17.1 gives 18.2.
What size water softener do I need in Stoughton?
For 3 people using 75 gallons each per day, 18.2 gpg works out to about 4,106 grains a day. A 32,000-grain softener covers that with a regeneration about every 7 days.
Has the Stoughton water system had EPA violations?
EPA records show no health-based violations for Stoughton Waterworks since 2016. There were also 1 monitoring or reporting violation, which are about late or missing tests and notices.
Nearby cities
- McFarland364 mg/LVery hard
- Oregon283 mg/LVery hard
- Edgerton291 mg/LVery hard
- Monona420 mg/LVery hard
- Fitchburg270 mg/LVery hard
- Cottage Grove347 mg/LVery hard
- Madison341 mg/LVery hard
- Verona360 mg/LVery hard
- Milton342 mg/LVery hard
- Sun Prairie337 mg/LVery hard
Hardness data: TapWaterData US Water Hardness (utility report, January 13, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.