Hard water in Waukesha, WI
Reported by Waukesha Water Utility · April 2024
- WI typical
- 170 mg/L
- EPA health violations since 2016
- 160
- Softener for 3 people
- 32k grain
- Data
- Utility report
Tap water in Waukesha has about 326 mg/L of hardness, which is 19.1 grains per gallon. On the USGS scale that counts as very hard. The number comes from Waukesha Water Utility, dated April 2024.
Waukesha sits 156 mg/L above the typical Wisconsin figure of 170. Of the 10 nearest cities we track, 5 have softer water and 5 have harder. The range nearby runs from 134 mg/L in Wauwatosa to 424 in Brookfield.
What 326 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 326 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 × 19.1 gpg = 4,286 grains a day. A 32,000-grain unit regenerates about every 7 days.
EPA record for Waukesha's water system
160 health-based violations since 2016
Serves about 70,718 people from surface water.
- Health-based
- 160
- Monitoring or reporting
- 28
- Open now
- 2
| Contaminant or rule | Violations | Period | Status |
|---|---|---|---|
| Combined radiumnaturally occurring radioactivity | 24 | 2021–2023 | Resolved |
| Gross alpha radioactivitynaturally occurring radioactivity | 16 | 2021–2023 | Resolved |
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 Waukesha water hard?
Yes. It measures about 326 mg/L (19.1 grains per gallon), which the USGS classes as very hard.
What is the water hardness in Waukesha in grains per gallon?
About 19.1 gpg. One grain per gallon equals 17.1 mg/L, so 326 mg/L divided by 17.1 gives 19.1.
What size water softener do I need in Waukesha?
For 3 people using 75 gallons each per day, 19.1 gpg works out to about 4,286 grains a day. A 32,000-grain softener covers that with a regeneration about every 7 days.
Has the Waukesha water system had EPA violations?
EPA records show 160 health-based violations for Waukesha Water Utility since 2016, involving Combined radium, Gross alpha radioactivity. There were also 28 monitoring or reporting violations, which are about late or missing tests and notices.
Nearby cities
- Pewaukee382 mg/LVery hard
- New Berlin330 mg/LVery hard
- Brookfield424 mg/LVery hard
- Sussex332 mg/LVery hard
- Lisbon332 mg/LVery hard
- West Allis135 mg/LHard
- Muskego276 mg/LVery hard
- Wauwatosa134 mg/LHard
- Menomonee Falls174 mg/LHard
- Greenfield135 mg/LHard
Hardness data: TapWaterData US Water Hardness (utility report, April 5, 2024), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.