Hard water in West Allis, WI
Reported by West Allis Waterworks · May 2025
- WI typical
- 170 mg/L
- EPA health violations since 2016
- 0
- Softener for 3 people
- 24k grain
- Data
- Utility report
The water in West Allis carries roughly 135 mg/L of dissolved calcium and magnesium, or 7.9 grains per gallon. That is hard water. The number comes from West Allis Waterworks, dated May 2025.
At 135 mg/L, West Allis is 35 mg/L below the typical Wisconsin figure of 170. Of the 10 nearest cities we track, 3 have softer water and 4 have harder. The range nearby runs from 130 mg/L in Shorewood to 424 in Brookfield.
What 135 mg/L means at home
Expect white crust on faucets and showerheads, plus spots on dishes that come out of the dishwasher.
Kettles collect scale quickly. Water heaters build up sediment at the bottom of the tank, which makes them work harder over time.
Soap and detergent need a little more to lather, and soap scum shows up in the tub.
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 135 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 × 7.9 gpg = 1,775 grains a day. A 24,000-grain unit regenerates about every 13 days.
EPA record for West Allis's water system
No health-based violations since 2016
Serves about 63,240 people from surface water.
- 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 West Allis water hard?
Yes. It measures about 135 mg/L (7.9 grains per gallon), which the USGS classes as hard.
What is the water hardness in West Allis in grains per gallon?
About 7.9 gpg. One grain per gallon equals 17.1 mg/L, so 135 mg/L divided by 17.1 gives 7.9.
What size water softener do I need in West Allis?
For 3 people using 75 gallons each per day, 7.9 gpg works out to about 1,775 grains a day. A 24,000-grain softener covers that with a regeneration about every 13 days.
Has the West Allis water system had EPA violations?
EPA records show no health-based violations for West Allis Waterworks since 2016.
Nearby cities
- Greenfield135 mg/LHard
- Wauwatosa134 mg/LHard
- Milwaukee135 mg/LHard
- New Berlin330 mg/LVery hard
- Brookfield424 mg/LVery hard
- St. Francis135 mg/LHard
- Franklin210 mg/LVery hard
- Shorewood130 mg/LHard
- Cudahy142 mg/LHard
- Glendale134 mg/LHard
Hardness data: TapWaterData US Water Hardness (utility report, May 27, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.