Public water system · MI0001250
ActiveCassopolis
At a glance
Cassopolis (PWSID MI0001250) is an active community water system in Cass County, Michigan. It reports serving 1,815 people through 842 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in March 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,815
Service connections
842
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Cassopolis compare with other water systems in Cass County?
By EPA's size categories, Cassopolis is a small system (501 to 3,300 people). Cass County has 135 active public water systems, and Cassopolis is the 2nd-largest of them by population served. Its population served is about 7.2 times the county average of 251 people per system, and accounts for 5.4% of the 33,840 people reported by systems filed under the county. Across Michigan, the 10,599 active systems average 847 people each. Nationally, the average active community water system reports serving 6,703 people, so Cassopolis 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. Michigan has 1,332 active community water systems, 13% of the state's 10,599 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 10,214 Michigan systems (96%) list groundwater as their primary source.
Who owns and regulates Cassopolis?
EPA lists Cassopolis as owned by a local government. The MI state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 5 of the 135 active systems in Cass County (3.7%) are also owned by a local government.
Does Cassopolis have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in March 2026. The violations listed here began between November 1995 and March 2026. By type: 9 monitoring and reporting, 1 monitoring, 1 reporting and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Chlorine (3 of them). EPA lists 9 as resolved and 3 as archived. 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. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2026-03-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Archived |
| 2026-03-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Archived |
| 2023-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2021-10-11 | ReportingReport Sample Result/Fail Monitor (RTCR) · code 4B | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2020-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2020-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2017-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2017-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2016-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Uraniumcode 4006 | No | Resolved |
| 2013-08-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2013-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 1995-11-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
The 12 most recent 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.
Cassopolis: frequently asked questions
Who runs Cassopolis?
Cassopolis (PWSID MI0001250) is a community water system owned by a local government. It is regulated by the MI state drinking water program.
How many people does Cassopolis serve?
Cassopolis reports serving 1,815 people through 842 service connections in Cass County, Michigan.
Where does Cassopolis 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 Cassopolis have any drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in March 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 Cassopolis' 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. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in March 2026. For current results, consult the system's annual water quality report, EPA ECHO, or the MI state drinking water program.
Where can I find Cassopolis' water quality report?
As a community water system, Cassopolis 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 Cass County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Dowagiac | Cass | 6,350 | Community | Groundwater |
| Cass County Water System | Cass | 1,350 | Community | Groundwater |
| Edwardsburg | Cass | 1,260 | Community | Groundwater |
| Marcellus | Cass | 1,198 | Community | Groundwater |
| Howard-Ellis Elementary | Cass | 780 | Non-transient non-community | Groundwater |
| Shady Point Campground West Well | Cass | 640 | 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, “Cassopolis, PWSID MI0001250, Michigan”, https://aquacensus.com/water-systems/michigan/cassopolis-mi0001250 (data as of October 1, 2026).