Hard water in Waunakee, WI
Reported by Waunakee Waterworks · September 2025
- WI typical
- 170 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 32k grain
- Data
- Utility report
Waunakee water measures 282 mg/L (16.5 gpg) of hardness, very hard by USGS standards. The number comes from Waunakee Waterworks, dated September 2025.
At 282 mg/L, Waunakee is 112 mg/L above the typical Wisconsin figure of 170. Of the 10 nearest cities we track, 2 have softer water and 8 have harder. The range nearby runs from 270 mg/L in Fitchburg to 420 in Monona.
What 282 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 282 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 × 16.5 gpg = 3,710 grains a day. A 32,000-grain unit regenerates about every 8 days.
EPA record for Waunakee's water system
No health-based violations since 2016
Serves about 14,879 people from groundwater.
- Health-based
- 0
- Monitoring or reporting
- 3
- 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 Waunakee water hard?
Yes. It measures about 282 mg/L (16.5 grains per gallon), which the USGS classes as very hard.
What is the water hardness in Waunakee in grains per gallon?
About 16.5 gpg. One grain per gallon equals 17.1 mg/L, so 282 mg/L divided by 17.1 gives 16.5.
What size water softener do I need in Waunakee?
For 3 people using 75 gallons each per day, 16.5 gpg works out to about 3,710 grains a day. A 32,000-grain softener covers that with a regeneration about every 8 days.
Has the Waunakee water system had EPA violations?
EPA records show no health-based violations for Waunakee Waterworks since 2016. There were also 3 monitoring or reporting violations, which are about late or missing tests and notices.
Nearby cities
- DeForest280 mg/LVery hard
- Middleton337 mg/LVery hard
- Madison341 mg/LVery hard
- Sun Prairie337 mg/LVery hard
- Monona420 mg/LVery hard
- Cottage Grove347 mg/LVery hard
- Fitchburg270 mg/LVery hard
- McFarland364 mg/LVery hard
- Verona360 mg/LVery hard
- Oregon283 mg/LVery hard
Hardness data: TapWaterData US Water Hardness (utility report, September 16, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.