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Fond du Lac, WI Tap Water Quality 2026

Water quality report for Fond du Lac, WI — PFAS, lead and copper results, violation history and state inspection findings from EPA SDWIS.

A look at Fond du Lac's drinking water using EPA enforcement records: violations, lead and copper results, PFAS sampling and state inspection findings.

Main Utility: Fond Du Lac Waterworks PWSID: WI4200469 Updated: 2026 Q2
✅

No federal limits exceeded on record

Lead is 6.10 ppb, 41% of the action level and no violations are open. No PFAS was detected.

C

Fond du Lac earns a C for water quality

Graded on violations, lead, and PFAS, with state inspection findings.

Lead: 6.10 ppb — 41% of the federal action level
PFAS tested, none detected
8 violations since 2015, 1 health-based
No violations currently open
Fond du Lac's lead level vs. all Wisconsin community water systems
0 ppb5 ppb10 ppb15 ppb
Lead level: 6.10 ppb — 41% of the federal action level
✓ Lower lead than 14% of Wisconsin utilities
Population Served
44236
~16049 connections
Water Source
Groundwater
Drawn from wells — SDWIS source code GW
Active Violations
0
8 since 2015, all resolved

Lead & Copper Testing

Lead (Pb)
90th percentile of tap samples collected across the distribution system
41% of EPA action level
6.10 ppb
Action level: 15 ppb
Copper (Cu)
90th percentile of tap samples. SDWIS reports a copper figure only when a system exceeds the action level, so any value here is an exceedance.
114.2% of EPA action level
1,484 ppb
Action level: 1,300 ppb
The 90th-percentile lead result is 6.10 ppb, 41% of the 15 ppb federal action level. The action level is a treatment trigger, not a legal maximum, and it is measured across sampled taps rather than at any single home. Copper reached the action level here; a copper figure appears in SDWIS only when a system triggers it.

Contaminant Violations (2015–Present)

ContaminantTypeMeasuredLimitPeriodStatus
LEAD AND COPPER RULE REVISIONS TREATMENT TECHNIQUE — — 2024 Resolved
Public Notice OTHER — — 2024 Resolved
Consumer Confidence Rule OTHER — — 2019 Resolved
Consumer Confidence Rule OTHER — — 2019 Resolved
TTHM MONITORING AND REPORTING — 0.080 mg/L 2016 Resolved
Total Haloacetic Acids (HAA5) MONITORING AND REPORTING — 0.060 mg/L 2016 Resolved
Coliform (TCR) MONITORING AND REPORTING — 5% of samples 2015 Resolved
Chlorine MONITORING AND REPORTING — 4.0 mg/L 2015 Resolved
Understanding violation types MCL violations mean a contaminant exceeded the federal maximum limit — the most serious type.
TT (Treatment Technique) violations mean required treatment procedures weren't followed, but don't necessarily mean contamination occurred.

Violation History

8 violations are on record since 2015, of which 1 were health-based. All have been resolved and none remain open.

About the Main Water System

Utility Fond Du Lac Waterworks
PWSID WI4200469
Water source Groundwater — Drawn from wells — SDWIS source code GW
Population served 44,236
Service connections 16,049
Systems serving this area 1
Regulator State primacy agency
Data through 2026 Q2 — EPA SDWIS

Frequently Asked Questions

Is Fond du Lac tap water safe to drink? ▼
No federal limit is exceeded on record. No violations are currently open. Lead is 6.10 ppb, 41% of the action level.
Does Fond du Lac water have PFAS? ▼
It was tested for the six regulated PFAS compounds and none were detected.
Who supplies water to Fond du Lac? ▼
Fond Du Lac Waterworks (PWSID WI4200469). Groundwater. Drawn from wells — SDWIS source code GW
When was this system last inspected? ▼
It was last inspected on 2026-03-12. No significant deficiencies were recorded.

What Should Fond du Lac Residents Do?

1
Consider a filter certified for lead
Look for NSF/ANSI 53 certification for lead reduction.
2
Check for a lead service line
Lead reaches tap water mainly through service lines and household plumbing. Suppliers now publish an inventory identifying lead lines.
3
Flush before drinking
If water has sat in pipes more than six hours, run the cold tap for two minutes before drinking or cooking.

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