Drinking Water Compliance OS

O'FALLON, MO · St. Charles County

ST MARYS INSTITUTE Water System

Inactive system

This water system is marked inactive in EPA’s federal records as of March 1, 1999. It is no longer an operating public water system under this PWSID, and no compliance deadlines — including the 2027 Consumer Confidence Report rule — apply to it.

If you are a resident looking for your current water provider, see water systems in St. Charles County, MO.

Data sourced from the EPA ECHO database (SDWA bulk download), last refreshed July 4, 2026. This is a record-keeping and public-information tool — it does not replace Missouri’s official records. Always confirm current status with Missouri before making decisions based on this information.

System facts

System ID (PWSID)
MO6069050
System type
Community Water System
Population served
150
Service connections
1
Ownership
privately owned
Water source
groundwater (wells)

Violation history

  • Monitoring, Regular

    Nitrate-Nitrite

    January 1, 1997 – December 31, 1997

    Archived
  • Monitoring, Routine Minor (TCR)

    Coliform (TCR)

    November 1, 1995 – November 30, 1995

    Archived
  • Monitoring, Routine Major (TCR)

    Coliform (TCR)

    October 1, 1994 – October 31, 1994

    Archived

Archived closed in EPA's records (typically due to age or a data correction)

Enforcement actions

No enforcement actions on record for this system.

Last known contact on file (system is inactive)

Not on record

314-240-3420

O'FALLON, MO 63366