Ozaukee County, Wisconsin
9 ZIP codes · Avg score 72/100 · Grade B · Updated 2026-06-03
Compared to state averages, Ozaukee County scores well — its 9 ZIP codes sit above the baseline for tap water quality.
How Ozaukee County Compares
How Ozaukee County Compares
Ozaukee County scores 6 points above the Wisconsin state average (66/100) and 4 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Ozaukee County, Wisconsin
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 11.5 (asthma 10.2%, diabetes 10.1%)
Estimated additional annual cost per homeowner: $1,461, driven primarily by flood
Infrastructure: 0.375% avg pipe failure probability, 25% of ZIPs at high risk
61.1% of homes built before 1978 (lead paint era)
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: $1,461
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
39,469 housing units in Ozaukee 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 Ozaukee County
Remediation costs are relatively manageable for most homeowners in Ozaukee 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 Ozaukee 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 Ozaukee County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Saukville Waterworks | 4,268 | 15 |
| 2 | Port Washington Waterworks | 12,853 | 12 |
| 3 | Cedarburg L & W Commission | 11,800 | 10 |
| 4 | Grafton Waterworks | 12,269 | 8 |
| 5 | Osprey Mobile Home Park | 150 | 8 |
22 total water systems serve Ozaukee County.
All ZIP Codes in Ozaukee County
9 ZIP codes tracked in Ozaukee County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 53021 | Fredonia | 83 | B | 1 | $278K |
| 2 | 53004 | Belgium | 82 | B | 2 (1 health) | $245K |
| 3 | 53074 | Port Washington | 78 | B | 4 | $276K |
| 4 | 53097 | Mequon | 74 | B | 5 (1 health) | $526K |
| 5 | 53012 | Cedarburg | 72 | B | 0 | $391K |
| 6 | 53024 | Grafton | 71 | B | 8 | $354K |
| 7 | 53080 | Saukville | 68 | C | 2 (1 health) | $292K |
| 8 | 53092 | Thiensville | 66 | C | 1 | $440K |
| 9 | 53060 | Newburg | 53 | D | 0 | — |
Recommended Buyer Guides for Ozaukee County
Eight risk categories drive the selection — PFAS exceedance, lead above EPA action level, pre-1978 housing share, EPA Radon Zone 1, flood-top-risk, wildfire-top-risk, multi-contaminant load, and a baseline fallback — and each category maps to a specific buyer-guide track that surfaces when the county data hits its threshold for that hazard signal.
- Best Lead Paint Test Kits — 61.1% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best Sump Pumps — Flood is the top compound risk factor
- Best Mold Test Kits — Flood-driven moisture and mold risk
Deep Dive Reports
Detailed analysis for Ozaukee County, Wisconsin
Overview
Ozaukee County in Wisconsin covers 9 ZIP codes with an average Home Safety Score of B (72/100).
7 of 9 ZIP codes have recorded EPA violations. 3 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.