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Lake Mills, WI Tap Water Quality 2026

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

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

Main Utility: Lake Mills Waterworks PWSID: WI1280108 Updated: 2026 Q2
✅

No federal limits exceeded on record

Lead is 4.60 ppb, 31% of the action level and no violations are open. No PFAS was detected.

C

Lake Mills earns a C for water quality

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

Lead: 4.60 ppb — 31% of the federal action level
PFAS tested, none detected
25 violations since 2015, 6 health-based
No violations currently open
Lake Mills's lead level vs. all Wisconsin community water systems
0 ppb5 ppb10 ppb15 ppb
Lead level: 4.60 ppb — 31% of the federal action level
✓ Lower lead than 20% of Wisconsin utilities
Population Served
6145
~2607 connections
Water Source
Groundwater
Drawn from wells — SDWIS source code GW
Active Violations
0
25 since 2015, all resolved

Lead & Copper Testing

Lead (Pb)
90th percentile of tap samples collected across the distribution system
31% of EPA action level
4.60 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.
123.1% of EPA action level
1,600 ppb
Action level: 1,300 ppb
The 90th-percentile lead result is 4.60 ppb, 31% 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 TREATMENT TECHNIQUE — TT 2022 Resolved
Consumer Confidence Rule OTHER — — 2020 Resolved
Consumer Confidence Rule OTHER — — 2020 Resolved
Public Notice OTHER — — 2018 Resolved
Lead and Copper Rule TREATMENT TECHNIQUE — TT 2017 Resolved
Combined Radium (-226 and -228) MCL EXCEEDANCE 5.5 PCI/L 5 pCi/L 2017 Resolved
Lead and Copper Rule MONITORING AND REPORTING — TT 2017 Resolved
Public Notice OTHER — — 2017 Resolved
Lead and Copper Rule MONITORING AND REPORTING — TT 2017 Resolved
Public Notice OTHER — — 2017 Resolved
Lead and Copper Rule MONITORING AND REPORTING — TT 2017 Resolved
Lead and Copper Rule MONITORING AND REPORTING — TT 2017 Resolved
Lead and Copper Rule MONITORING AND REPORTING — TT 2017 Resolved
Lead and Copper Rule MONITORING AND REPORTING — TT 2017 Resolved
Lead and Copper Rule MONITORING AND REPORTING — TT 2017 Resolved
Lead and Copper Rule MONITORING AND REPORTING — TT 2017 Resolved
Lead and Copper Rule MONITORING AND REPORTING — TT 2017 Resolved
Lead and Copper Rule MONITORING AND REPORTING — TT 2016 Unaddressed
Lead and Copper Rule MONITORING AND REPORTING — TT 2016 Resolved
Lead and Copper Rule TREATMENT TECHNIQUE — TT 2016 Resolved
Lead and Copper Rule TREATMENT TECHNIQUE — TT 2016 Resolved
Lead and Copper Rule TREATMENT TECHNIQUE — TT 2016 Resolved
Public Notice OTHER — — 2016 Resolved
Public Notice OTHER — — 2016 Resolved
Lead and Copper Rule MONITORING AND REPORTING — TT 2016 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

25 violations are on record since 2015, of which 6 were health-based. All have been resolved and none remain open.

About the Main Water System

Utility Lake Mills Waterworks
PWSID WI1280108
Water source Groundwater — Drawn from wells — SDWIS source code GW
Population served 6,145
Service connections 2,607
Systems serving this area 1
Regulator State primacy agency
Data through 2026 Q2 — EPA SDWIS

Frequently Asked Questions

Is Lake Mills tap water safe to drink? ▼
No federal limit is exceeded on record. No violations are currently open. Lead is 4.60 ppb, 31% of the action level.
Does Lake Mills water have PFAS? ▼
It was tested for the six regulated PFAS compounds and none were detected.
Who supplies water to Lake Mills? ▼
Lake Mills Waterworks (PWSID WI1280108). Groundwater. Drawn from wells — SDWIS source code GW
When was this system last inspected? ▼
It was last inspected on 2026-01-14. No significant deficiencies were recorded.

What Should Lake Mills Residents Do?

1
Read your annual water report
Your supplier publishes a Consumer Confidence Report each July covering the prior year.
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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