COUNTY REPORT WI

Fond du Lac County, Wisconsin

18 ZIP codes · Avg score 53/100 · Grade D · Updated 2026-06-04

Compared to state averages, Fond du Lac County scores below the baseline — health violations appear more frequently than the norm across its 18 ZIP codes.

How Fond du Lac County Compares

Fond du Lac County53/100
Wisconsin avg66/100
National avg68/100

How Fond du Lac County Compares

D
County Grade
53/100
Avg Safety Score
18
ZIP Codes
22
Water Systems

Fond du Lac County scores 13 points below the Wisconsin state average (66/100) and 15 points below the national average (68/100).

Data: EPA SDWIS Last verified: 2026-06-04

D
County Grade
53
Avg Safety Score
18
ZIP Codes
Best ZIP: 53011 (70/100)
Lowest ZIP: 54979 (40/100)
$243K
Median Home Value
$2,089
Avg Remediation (86% of home value)

ZIP Code Risk Map

Water Quality Map: Fond du Lac County, Wisconsin

Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.

A B C D F

Key Risk Factors

Health risk index: 13.6 (asthma 11%, diabetes 11.5%)

Estimated additional annual cost per homeowner: $972, driven primarily by energy_code_gap

Infrastructure: 0.399% avg pipe failure probability, 39% of ZIPs at high risk

68.6% of homes built before 1978 (lead paint era)

Violation History (2023–2025)

→ Stable trend

EPA violation counts by year across Fond du Lac County water systems. Health-based shown in red, total in blue.

2023
1 (1 health)
2024
14 (14 health)
2025
1 (1 health)

Peak year: 2024 with 14 violations. Past 5 years: 16 total (16 health-based).

Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.

County Health Indicators vs National Average

Asthma 11% (national: 8.9%)
Diabetes 11.5% (national: 10.5%)
Obesity 43.6% (national: 32.4%)

Black markers indicate national averages. Source: CDC PLACES, Census ACS.

Infrastructure Overview

1970
Median Build Year
68.6%
Pre-1978 Housing
40%
Pipe Failure Probability
39%
ZIPs at High Infra Risk
High
Lead Pipe Risk

Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.

Compound Risk Breakdown

Estimated additional annual cost per homeowner: $972

Energy Code Gap $345/yr
Flood $322/yr
Water / Lead $225/yr

Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).

Housing Age Distribution

50,282 housing units in Fond du Lac County

Pre-1940 25%
1940–1959 14%
1960–1979 24%
1980–1999 21%
2000+ 16%

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 Fond du Lac County

$243K
Median Home Value
$2,089
Est. Remediation Cost
0.9%
of Home Value
Remediation as % of home value low burden

Remediation costs are relatively manageable for most homeowners in Fond du Lac 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 Fond du Lac County residents

Asthma 11% (US avg: 8.9%)
Diabetes 11.5% (US avg: 11%)
Obesity 43.6% (US avg: 32.4%)

Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.

Water Systems with Most Violations

Top 5 systems in Fond du Lac County ranked by EPA violation count.

# Water System Population Violations
1 FOND DU LAC WATERWORKS 44,303 39
2 Ashwood Grove Edgewater 1,046 39
3 Fond Du Lac Tn Water Utility 980 39
4 Woodland Park 66 39
5 Mary Hill Park Sanitary District 65 39

22 total water systems serve Fond du Lac County.

All ZIP Codes in Fond du Lac County

18 ZIP codes tracked in Fond du Lac County.

# ZIP Code City Safety Score Grade Violations Home Value
1 53011 Cascade 70 B 0 $244K
2 53065 Oakfield 70 B 0 $247K
3 53019 Eden 66 C 0 $227K
4 53057 Mount Calvary 66 C 0 $230K
5 53010 Campbellsport 65 C 10 $276K
6 53931 Fairwater 65 C 2 $130K
7 53963 Waupun 61 C 7 (1 health) $183K
8 53919 Brandon 60 C 0 $211K
9 53049 Malone 53 D 0 $271K
10 54936 Fond Du Lac 49 D 13 (2 health)
11 54937 Fond Du Lac 47 D 13 (2 health) $262K
12 54971 Ripon 44 D 2 (1 health) $183K
13 54935 Fond Du Lac 42 D 13 (2 health) $166K
14 53079 Saint Cloud 40 D 0 $243K
15 54932 Eldorado 40 D 0 $256K
16 54964 Pickett 40 D 0 $233K
17 54974 Rosendale 40 D 0 $250K
18 54979 Van Dyne 40 D 0 $262K

Recommended Buyer Guides for Fond du Lac County

Four sources — EPA, NSF, FEMA, CDC — drive the match.

Overview

Fond du Lac County in Wisconsin covers 18 ZIP codes with an average Home Safety Score of D (53/100).

7 of 18 ZIP codes have recorded EPA violations. 8 health-based violations have been documented.

← Back to Wisconsin water quality report

Data Sources

Updated daily.

What You Can Do

Fond du Lac County has a grade of D. Here are steps to protect your household.

1

Test your tap water

Order a certified lab test kit ($20-$50) to check for lead, bacteria, and other contaminants specific to your ZIP code.

2

Consider a certified water filter

NSF-certified filters can remove most common contaminants. Match the filter to your test results for best protection. Try our filter matcher

3

Contact your water utility

Request the latest Consumer Confidence Report (CCR) from your water provider. It details exactly what was found in your water supply.

4

Check for lead in your home

68.6% of homes in this county were built before 1978. Older plumbing and solder can leach lead into drinking water, especially in the morning.

Frequently Asked Questions

Is water safe in Fond du Lac County?
Fond du Lac County receives a grade of D. 5 of 18 ZIP codes have health-based violations. Independent water testing is recommended.
How many water systems serve Fond du Lac County?
Fond du Lac County is served by 22 public water systems that supply drinking water to residents across 18 ZIP codes.
What is the biggest environmental risk in Fond du Lac County?
The primary environmental risk factor in Fond du Lac County is energy_code_gap. This contributes to an estimated additional annual cost of $972 per homeowner.
How old are homes in Fond du Lac County?
The median home build year in Fond du Lac County is 1970. 68.6% of homes were built before 1978, which means they may contain lead-based paint and older plumbing materials.
How does Fond du Lac County compare to Wisconsin?
Fond du Lac County has an average water safety score of 53/100, which is below the Wisconsin state average of 66/100.

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