Hard water in Pewaukee, WI

Tap water hardness
382mg/L
22.3gpg
Very hard

Reported by Pewaukee City Water and Sewer Utility · September 2025

WI typical
170 mg/L
EPA health violations since 2016
18
Softener for 3 people
48k grain
Data
Utility report

The water in Pewaukee carries roughly 382 mg/L of dissolved calcium and magnesium, or 22.3 grains per gallon. That is very hard water. The number comes from Pewaukee City Water and Sewer Utility, dated September 2025.

Pewaukee on the hardness scale, with nearby cities
060120180240300360+WI typical 170Wauwatosa: 134 mg/LWauwatosa 134West Allis: 135 mg/LWest Allis 135Menomonee Falls: 174 mg/LMenomonee Falls 174Oconomowoc: 310 mg/LOconomowoc 310Waukesha: 326 mg/LWaukesha 326New Berlin: 330 mg/LNew Berlin 330Sussex: 332 mg/LSussex 332Lisbon: 332 mg/LLisbon 332Brookfield: 424 mg/LBrookfield 424Germantown: 422 mg/LGermantown 422Pewaukee 382off the scalemg/L as calcium carbonate060120180240300360+WI 170Menomonee Falls: 174 mg/LMenomonee. 174Waukesha: 326 mg/LWaukesha 326New Berlin: 330 mg/LNew Berlin 330Sussex: 332 mg/LSussex 332Lisbon: 332 mg/LLisbon 332Brookfield: 424 mg/LBrookfield 424382 mg/Loff the scalemg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

At 382 mg/L, Pewaukee is 212 mg/L above the typical Wisconsin figure of 170. Of the 10 nearest cities we track, 8 have softer water and 2 have harder. The range nearby runs from 134 mg/L in Wauwatosa to 424 in Brookfield.

What 382 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 382 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.

Softener size for Pewaukee

3 people × 75 gallons a day × 22.3 gpg = 5,022 grains a day. A 48,000-grain unit regenerates about every 9 days.

Size it for your household

EPA record for Pewaukee's water system

Pewaukee City Water and Sewer Utility · PWSID WI2680214

18 health-based violations since 2016

Serves about 8,671 people from groundwater.

Health-based
18
Monitoring or reporting
54
Open now
2
20162017201820192020202120222023202420252026Gross alpha radioactivityCombined radium'16'18'20'22'24'26Gross alpha radioactivityCombined radium
Each dot is one health-based violation, placed at the start of its compliance period.
Contaminant or ruleViolationsPeriodStatus
Gross alpha radioactivitynaturally occurring radioactivity112023–2026Resolved
Combined radiumnaturally occurring radioactivity72017–2019Resolved

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 Pewaukee water hard?

Yes. It measures about 382 mg/L (22.3 grains per gallon), which the USGS classes as very hard.

What is the water hardness in Pewaukee in grains per gallon?

About 22.3 gpg. One grain per gallon equals 17.1 mg/L, so 382 mg/L divided by 17.1 gives 22.3.

What size water softener do I need in Pewaukee?

For 3 people using 75 gallons each per day, 22.3 gpg works out to about 5,022 grains a day. A 48,000-grain softener covers that with a regeneration about every 9 days.

Has the Pewaukee water system had EPA violations?

EPA records show 18 health-based violations for Pewaukee City Water and Sewer Utility since 2016, involving Gross alpha radioactivity, Combined radium. There were also 54 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 112 cities in Wisconsin

Hardness data: TapWaterData US Water Hardness (utility report, September 23, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.