Waukesha County, Wisconsin
32 ZIP codes · Avg score 58/100 · Grade C · Updated 2026-06-04
In recent monitoring cycles, Waukesha County's 32 ZIP codes show a split record — several have documented water safety violations.
How Waukesha County Compares
How Waukesha County Compares
Waukesha County scores 8 points below the Wisconsin state average (66/100) and 10 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-04
ZIP Code Risk Map
Water Quality Map: Waukesha County, Wisconsin
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 11.8 (asthma 10.2%, diabetes 10.5%)
Estimated additional annual cost per homeowner: $1,014, driven primarily by flood
Infrastructure: 0.378% avg pipe failure probability, 33% of ZIPs at high risk
59.5% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
↑ Worsening trendEPA violation counts by year across Waukesha County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 53 violations. Past 5 years: 177 total (177 health-based). Health-based violations are rising versus the prior 2-year window — worth closer monitoring.
Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $1,014
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
176,283 housing units in Waukesha County
Source: U.S. Census Bureau ACS B25034 (Year Structure Built).
Water Safety Affordability
How much it costs to fix water issues relative to home values in Waukesha County
Remediation costs are relatively manageable for most homeowners in Waukesha County, representing a small fraction of property value.
Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.
Health Outcomes vs National Average
CDC PLACES data for Waukesha County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 5 systems in Waukesha County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Waukesha Water Utility | 70,718 | 147 |
| 2 | Pewaukee City Water and Sewer Utility | 8,671 | 102 |
| 3 | Lake Meadows Water Trust | 750 | 101 |
| 4 | Brookfield Water Utility | 29,070 | 100 |
| 5 | Lake Drive Water Trust | 500 | 98 |
64 total water systems serve Waukesha County.
All ZIP Codes in Waukesha County
32 ZIP codes tracked in Waukesha County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 53017 | Colgate | 70 | B | 0 | $477K |
| 2 | 53058 | Nashotah | 70 | B | 0 | $506K |
| 3 | 53064 | North Lake | 69 | C | 3 (1 health) | — |
| 4 | 53149 | Mukwonago | 69 | C | 10 (1 health) | $385K |
| 5 | 53146 | New Berlin | 68 | C | 1 | $319K |
| 6 | 53183 | Wales | 68 | C | 5 (2 health) | $383K |
| 7 | 53007 | Butler | 67 | C | 3 | $216K |
| 8 | 53018 | Delafield | 67 | C | 14 (3 health) | $485K |
| 9 | 53069 | Okauchee | 66 | C | 0 | $399K |
| 10 | 53089 | Sussex | 66 | C | 6 (1 health) | $387K |
| 11 | 53119 | Eagle | 66 | C | 0 | $374K |
| 12 | 53008 | Brookfield | 65 | C | 7 (1 health) | — |
| 13 | 53005 | Brookfield | 64 | C | 7 (1 health) | $386K |
| 14 | 53045 | Brookfield | 64 | C | 7 (1 health) | $444K |
| 15 | 53046 | Lannon | 64 | C | 2 | $256K |
| 16 | 53052 | Menomonee Falls | 64 | C | 1 | — |
| 17 | 53150 | Muskego | 64 | C | 9 (1 health) | $391K |
| 18 | 53118 | Dousman | 63 | C | 20 (7 health) | $367K |
| 19 | 53153 | North Prairie | 62 | C | 5 | $394K |
| 20 | 53122 | Elm Grove | 59 | C | 6 (1 health) | $470K |
| 21 | 53051 | Menomonee Falls | 58 | C | 1 | $342K |
| 22 | 53151 | New Berlin | 58 | C | 1 | $351K |
| 23 | 53066 | Oconomowoc | 54 | D | 6 | $403K |
| 24 | 53103 | Big Bend | 53 | D | 0 | $381K |
| 25 | 53029 | Hartland | 48 | D | 1 | $450K |
| 26 | 53189 | Waukesha | 46 | D | 23 (12 health) | $373K |
| 27 | 53186 | Waukesha | 41 | D | 23 (12 health) | $278K |
| 28 | 53188 | Waukesha | 41 | D | 23 (12 health) | $317K |
| 29 | 53056 | Merton | 40 | D | 0 | — |
| 30 | 53072 | Pewaukee | 40 | D | 49 (27 health) | $424K |
| 31 | 53127 | Genesee Depot | 40 | D | 0 | — |
| 32 | 53187 | Waukesha | 36 | F | 23 (12 health) | — |
Recommended Buyer Guides for Waukesha County
Below: editorial picks, no sponsored placements.
- Best Water Filters for PFAS — PFAS detected in 1 ZIP code
- Best Lead Paint Test Kits — 59.5% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
- Best Sump Pumps — Flood is the top compound risk factor
Deep Dive Reports
Detailed analysis for Waukesha County, Wisconsin
Overview
Waukesha County in Wisconsin covers 32 ZIP codes with an average Home Safety Score of C (58/100).
25 of 32 ZIP codes have recorded EPA violations. 95 health-based violations have been documented.
← Back to Wisconsin water quality report
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Updated daily.