Water Hardness in Wauwatosa, WI
Wisconsin · 2 zip codes · 15 matched water systems
City avg (weighted): 140 PPM
Dataset updated March 9, 202615 matched water systems in the city rollupIndividual systems and ZIPs can differ. Methodology
Is Wauwatosa, WI Water Hard or Soft?
The displayed hardness for Wauwatosa, WI is 140 PPM (8.2 GPG) from Milwaukee Waterworks, classified as moderately hard. The citywide weighted average is 140 PPM.
Water hardness is not a drinking-water safety score. It measures calcium and magnesium minerals, and address-level results can shift by pressure zone, supply blend, building plumbing, or private well.
How this city reading is built
This city reading is a weighted rollup across 15 matched water systems and 2 ZIP codes. Citywide readings are useful for comparison, but individual utility zones and ZIPs can differ.
Hardness is a mineral-content reading, not a drinking-water safety rating. Use it for scale, appliance, and softener decisions; check your utility report or test your tap before sizing treatment equipment. See how we calculate local readings.
Water Systems in Wauwatosa
These systems are matched to Wauwatosa, WI. Citywide readings are useful for comparison, but the system serving a specific address may differ from the city average.
| Water System | Source | Hardness | Pop. Served |
|---|---|---|---|
| Milwaukee Waterworks WI2410100 | surface water | 140 PPM Moderately HardUSGS estimate: 247 PPM | |
| West Allis Waterworks WI2410595 | surface water | 140 PPM Moderately HardUSGS estimate: 247 PPM | |
| Wauwatosa Waterworks WI2410596 | surface water | 140 PPM Moderately HardUSGS estimate: 247 PPM | |
| North Shore Water Commission WI2413515 | surface water | 140 PPM Moderately HardUSGS estimate: 281 PPM | |
| Oak Creek Waterworks WI2410172 | surface water | 140 PPM Moderately HardUSGS estimate: 247 PPM |
Zip Codes in Wauwatosa, WI
What This Means For You
Use this city reading as a local planning estimate, not a final treatment specification. Hardness can vary by utility zone, seasonal blend, private well, and building plumbing. Confirm your tap reading with a utility report or home hardness test before sizing equipment.
Know your water hardness?
If you've tested your water or have your utility's CCR report, share your reading to help us improve accuracy for Wauwatosa, WI.
Frequently Asked Questions
How hard is the water in Wauwatosa, WI?
The citywide weighted average water hardness in Wauwatosa, WI is 140 PPM (8.2 GPG), classified as moderately hard. This is based on 15 matched water systems.
Do I need a water softener in Wauwatosa, WI?
With a citywide average hardness of 140 PPM, a water softener is worth considering for homes in Wauwatosa. Confirm your tap reading before sizing equipment.
Is hard water in Wauwatosa, WI safe to drink?
Water hardness itself is a mineral-content reading, not a drinking-water safety rating. Calcium and magnesium are naturally occurring minerals, but you should check your utility's Consumer Confidence Report for contaminant and compliance information.
How many water systems serve Wauwatosa, WI?
Wauwatosa, Wisconsin is served by 15 matched water systems across 2 zip codes.
Learn More About Your Water
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