Public water system · MO1010123
ActiveCalhoun Pws
At a glance
Calhoun Pws (PWSID MO1010123) is an active community water system in Henry County, Missouri. It reports serving 324 people through 163 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list 10 violations for this system; 5 are health-based, and the most recent began in February 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
324
Service connections
163
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Calhoun Pws compare with other water systems in Henry County?
By EPA's size categories, Calhoun Pws is a very small system (500 people or fewer). Henry County has 13 active public water systems. Its population served is well below the county average of 1,797 people per system, and accounts for 1.4% of the 23,361 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 Calhoun Pws is well below 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. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 179 Missouri systems (6.1%) list purchased surface water as their primary source.
Who owns and regulates Calhoun Pws?
EPA lists Calhoun 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. 10 of the 13 active systems in Henry County (77%) are also owned by a local government.
Does Calhoun Pws have drinking water violations?
EPA's records list 10 violations for this system; 5 are health-based, and the most recent began in February 2026. The violations listed here began between April 1999 and February 2026. By type: 5 contaminant level above the legal limit, 3 monitoring and reporting and 2 monitoring. The contaminant or rule involved most often is Total trihalomethanes (TTHM) (4 of them). EPA lists 10 as resolved. 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.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2026-02-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2019-06-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2016-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2016-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2016-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2015-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2009-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2005-08-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2001-02-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1999-04-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
All 10 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.
Calhoun Pws: frequently asked questions
Who runs Calhoun Pws?
Calhoun Pws (PWSID MO1010123) is a community water system owned by a local government. It is regulated by the MO state drinking water program.
How many people does Calhoun Pws serve?
Calhoun Pws reports serving 324 people through 163 service connections in Henry County, Missouri.
Where does Calhoun Pws get its water?
EPA SDWIS lists this system's primary water source as purchased surface water. Purchased surface water means the system buys surface water from another public water system rather than drawing its own.
Does Calhoun Pws have any drinking water violations?
EPA's records list 10 violations for this system; 5 are health-based, and the most recent began in February 2026. 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 Calhoun 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 10 violations for this system; 5 are health-based, and the most recent began in February 2026. For current results, consult the system's annual water quality report, EPA ECHO, or the MO state drinking water program.
Where can I find Calhoun Pws' water quality report?
As a community water system, Calhoun 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 Henry County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Henry County Water Company | Henry | 11,373 | Community | Surface water |
| Henry County Pwsd 3 | Henry | 2,993 | Community | Purchased surface water |
| Windsor Pws | Henry | 2,900 | Community | Groundwater |
| Harry S Truman Pwsd 2 | Henry + 1 more | 2,700 | Community | Surface water |
| Henry County Pwsd 4 | Henry | 1,140 | Community | Purchased surface water |
| Urich Pws | Henry | 505 | Community | Purchased surface water |
Related pages
Working with water-system records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.
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, “Calhoun Pws, PWSID MO1010123, Missouri”, https://aquacensus.com/water-systems/missouri/calhoun-pws-mo1010123 (data as of October 1, 2026).