Community Water System · PWS MO4036059
Terre Du Lac
Operator location Des Peres, Missouri - 80% of 456 violations are health-based (upper-third health share (> 23%)); groundwater source; 3,200 served per SDWIS.
- 3,200
- People served (this PWS)
- 456
- EPA violations (this PWS)
- 365
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Terre Du Lac standing, high SDWIS violation third
80% of 456 recorded violations are health-based - upper-third health share (> 23%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 80% is upper-third health share (> 23%). Population rank #10,162 of 29,740 among systems serving 500+.
The verdict
Terre Du Lac sits in the upper third of the sitemap cohort by violation count (456), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is mid-pack at 3,200 (mid served population (≤ 3,309)). Health-based share is 80% - most of this ledger is MCL or treatment-technique exceedance. No UCMR5 PFAS test appears for this system in this extract.
- #10,162 of 29,740
- Population · /systems
- #223 of 738
- Population · MO
- 456
- Total EPA violations on record
- 80%
- Health-based (MCL / treatment failure)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
System Details
- System Type
- Community
- Owner Type
- Private
- Connections
- 1,351
- County
- St. Francois
- School/Daycare
- No
- MCL Violations
- 365
- Monitoring Violations
- 31
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Combined Radium (-226 and -228) | MCL | 198 | 2016 |
| Gross Alpha, Excl. Radon and U | MCL | 155 | 2012 |
| Public Notice | Other | 42 | 2017 |
| Coliform (TCR) | MR | 16 | 2010 |
| Coliform (TCR) | MCL | 12 | 2008 |
| Consumer Confidence Rule | Other | 9 | 2020 |
| Lead and Copper Rule | MR | 6 | 2009 |
| Groundwater Rule | Other | 3 | 2016 |
| Gross Alpha, Excl. Radon and U | MR | 3 | 1995 |
| Combined Uranium | MR | 2 | 2012 |
| Radium-228 | MR | 2 | 2012 |
| Radium-226 | MR | 2 | 2012 |
Violation Count vs. the National Corpus
Terre Du Lac has 456 recorded EPA violations, 95% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 5% carry more. 80% of this system's own violations are health-based (365 of 456), and it ranks #10,162 of 29,740 by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
456 Higher than most more violations than 95% of 29,740 water systems
the national water-system corpus, bucketed by value
Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source EPA SDWIS · 2026-05-15
Health-based violations on Terre Du Lac
365 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for MO4036059.
Sources: EPA SDWIS · Missouri DNR, Public Drinking Water Branch
Nationwide peers
456 violations · 3,200 served: nearest cross-state SDWIS matches.
Cross-state systems with comparable violation load
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
Cross-state systems near this population served
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Terre Du Lac
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Missouri compares on the same EPA violation measures. Missouri systems
- Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
- Find and compare another public water system by name or PWSID. Search systems
EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.