Public water system · MO6010849
ActiveWentzville Pws
At a glance
Wentzville Pws (PWSID MO6010849) is an active community water system in St. Charles County, Missouri. It reports serving 41,784 people through 16,546 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 7 violations for this system; 2 are health-based, and the most recent began in July 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
41,784
Service connections
16,546
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Wentzville Pws compare with other water systems in St. Charles County?
By EPA's size categories, Wentzville Pws is a large system (10,001 to 100,000 people). St. Charles County has 54 active public water systems, and Wentzville Pws is the 4th-largest of them by population served. Its population served is about 7.1 times the county average of 5,867 people per system, and accounts for 13% of the 316,837 people reported by systems filed under the county. Across Missouri, the 2,943 active systems average 2,049 people each. Nationally, the average active community water system reports serving 6,703 people, so Wentzville Pws is about 6.2 times that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. Missouri has 1,612 active community water systems, 55% of the state's 2,943 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 2,521 Missouri systems (86%) list groundwater as their primary source.
Who owns and regulates Wentzville Pws?
EPA lists Wentzville Pws as owned by a local government. The MO state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 20 of the 54 active systems in St. Charles County (37%) are also owned by a local government.
Does Wentzville Pws have drinking water violations?
EPA's records list 7 violations for this system; 2 are health-based, and the most recent began in July 2025. The violations listed here began between March 1991 and July 2025. By type: 3 monitoring and reporting, 2 contaminant level above the legal limit, 1 reporting and 1 monitoring. The contaminant or rule involved most often is Total coliform bacteria (TCR) (5 of them). EPA lists 6 as resolved and 1 as unaddressed. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2025-07-02 | ReportingNotification, Known or Potential LSL · code 4H | Lead and Copper Rule Revisionscode 5200 | No | Unaddressed |
| 2018-08-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2007-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2005-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2003-11-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1991-05-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1991-03-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
All 7 violations in EPA's records, newest first.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
Wentzville Pws: frequently asked questions
Who runs Wentzville Pws?
Wentzville Pws (PWSID MO6010849) is a community water system owned by a local government. It is regulated by the MO state drinking water program.
How many people does Wentzville Pws serve?
Wentzville Pws reports serving 41,784 people through 16,546 service connections in St. Charles County, Missouri.
Where does Wentzville Pws get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does Wentzville Pws have any drinking water violations?
EPA's records list 7 violations for this system; 2 are health-based, and the most recent began in July 2025. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is Wentzville Pws' water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. EPA's records list 7 violations for this system; 2 are health-based, and the most recent began in July 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the MO state drinking water program.
Where can I find Wentzville Pws' water quality report?
As a community water system, Wentzville Pws must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
Other water systems in St. Charles County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| St Charles County Pwsd 2 | St. Charles | 100,587 | Community | Purchased surface water |
| St Charles Pws | St. Charles | 78,961 | Community | Purchased surface water |
| St Peters Pws | St. Charles | 52,575 | Community | Purchased surface water |
| Ofallon Pws | St. Charles | 32,515 | Community | Purchased surface water |
| St Paul Pws | St. Charles | 1,700 | Community | Groundwater |
| Orchard Farm Schools | St. Charles | 1,600 | Non-transient non-community | Groundwater |
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About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “Wentzville Pws, PWSID MO6010849, Missouri”, https://aquacensus.com/water-systems/missouri/wentzville-pws-mo6010849 (data as of October 1, 2026).