States ›Missouri ›St. Francois County ›Terre du Lac

Terre du Lac, MO Tap Water Quality 2026

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

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

Main Utility: Terre Du Lac PWSID: MO4036059 Updated: 2026 Q2
✅

No federal limits exceeded on record

Lead is 3.90 ppb, 26% of the action level and no violations are open. PFAS has never been sampled at this system.

B

Terre du Lac earns a B for water quality

Graded on violations and lead, with state inspection findings. PFAS not tested.

Lead: 3.90 ppb — 26% of the federal action level
PFAS never sampled at this system
10 violations since 2015, 5 health-based
No violations currently open
Terre du Lac's lead level vs. all Missouri community water systems
0 ppb5 ppb10 ppb15 ppb
Lead level: 3.90 ppb — 26% of the federal action level
✓ Lower lead than 23% of Missouri utilities
Population Served
2020
~1351 connections
Water Source
Groundwater
Drawn from wells — SDWIS source code GW
Active Violations
0
10 since 2015, all resolved

Lead & Copper Testing

Lead (Pb)
90th percentile of tap samples collected across the distribution system
26% of EPA action level
3.90 ppb
Action level: 15 ppb
The 90th-percentile lead result is 3.90 ppb, 26% 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.

Contaminant Violations (2015–Present)

ContaminantTypeMeasuredLimitPeriodStatus
Consumer Confidence Rule OTHER — — 2020 Resolved
Public Notice OTHER — — 2017 Resolved
Public Notice OTHER — — 2016 Resolved
Public Notice OTHER — — 2016 Resolved
Groundwater Rule OTHER — — 2016 Resolved
Combined Radium (-226 and -228) MCL EXCEEDANCE 10.4 PCI/L 5 pCi/L 2016 Resolved
Combined Radium (-226 and -228) MCL EXCEEDANCE 8.88 PCI/L 5 pCi/L 2015–2016 Resolved
Combined Radium (-226 and -228) MCL EXCEEDANCE 8.43 PCI/L 5 pCi/L 2015–2016 Resolved
Combined Radium (-226 and -228) MCL EXCEEDANCE 8.05 PCI/L 5 pCi/L 2015–2016 Resolved
Combined Radium (-226 and -228) MCL EXCEEDANCE 6.2 PCI/L 5 pCi/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

10 violations are on record since 2015, of which 5 were health-based. All have been resolved and none remain open.

About the Main Water System

Utility Terre Du Lac
PWSID MO4036059
Water source Groundwater — Drawn from wells — SDWIS source code GW
Population served 2,020
Service connections 1,351
Systems serving this area 1
Regulator State primacy agency
Data through 2026 Q2 — EPA SDWIS

Frequently Asked Questions

Is Terre du Lac tap water safe to drink? ▼
No federal limit is exceeded on record. No violations are currently open. Lead is 3.90 ppb, 26% of the action level.
Does Terre du Lac water have PFAS? ▼
This system has never been sampled for PFAS. EPA's national monitoring covered systems serving 3,300 people or more, so no results exist — which is not evidence that none is present.
Who supplies water to Terre du Lac? ▼
Terre Du Lac (PWSID MO4036059). Groundwater. Drawn from wells — SDWIS source code GW
When was this system last inspected? ▼
It was last inspected on 2024-07-30. No significant deficiencies were recorded.

What Should Terre du Lac 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.

Nearby Cities in Missouri

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