Is Lake Saint Louis, Missouri tap water safe?
2 water systems report serving Lake Saint Louis. Your water depends on which one serves your address. Check your bill if unsure. This list is matched from the ZIP codes in this place, so it may include nearby systems.
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St Charles County PWSD 2
Serves 100,587 people · Surface water · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2026).
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Wentzville PWS
Serves 41,784 people · Groundwater · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; 1 not yet resolved; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).