Public water system · MI0005030
ActiveOntonagon
At a glance
Ontonagon (PWSID MI0005030) is an active community water system in Ontonagon County, Michigan. It reports serving 2,607 people through 1,431 service connections. Its primary water source is surface water, and EPA lists it as owned by a local government. EPA's records list 4 violations for this system; none is health-based, and the most recent began in June 2017.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
2,607
Service connections
1,431
Primary source
SW
Surface water
System type
CWS
Community water system
System record
How does Ontonagon compare with other water systems in Ontonagon County?
By EPA's size categories, Ontonagon is a small system (501 to 3,300 people). Ontonagon County has 25 active public water systems, and Ontonagon is the largest of them by population served. Its population served is about 12 times the county average of 211 people per system, and accounts for 49% of the 5,270 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 Ontonagon is about 61% 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. Surface water means the system draws its water from rivers, lakes, streams or reservoirs. 68 Michigan systems (0.6%) list surface water as their primary source.
Who owns and regulates Ontonagon?
EPA lists Ontonagon 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 25 active systems in Ontonagon County (20%) are also owned by a local government.
Does Ontonagon have drinking water violations?
EPA's records list 4 violations for this system; none is health-based, and the most recent began in June 2017. The violations listed here began between August 1993 and June 2017. By type: 4 monitoring and reporting. The contaminants or rules involved are Interim Enhanced Surface Water Treatment Rule, Total trihalomethanes (TTHM), Haloacetic acids (HAA5) and Total coliform bacteria (TCR). EPA lists 4 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 |
|---|---|---|---|---|
| 2017-06-01 | Monitoring and reportingFailure Submit Filter Profile/CPE Report · code 29 | Interim Enhanced Surface Water Treatment Rulecode 0300 | No | Resolved |
| 2016-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2016-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 1993-08-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
All 4 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.
Ontonagon: frequently asked questions
Who runs Ontonagon?
Ontonagon (PWSID MI0005030) is a community water system owned by a local government. It is regulated by the MI state drinking water program.
How many people does Ontonagon serve?
Ontonagon reports serving 2,607 people through 1,431 service connections in Ontonagon County, Michigan.
Where does Ontonagon get its water?
EPA SDWIS lists this system's primary water source as surface water. Surface water means the system draws its water from rivers, lakes, streams or reservoirs.
Does Ontonagon have any drinking water violations?
EPA's records list 4 violations for this system; none is health-based, and the most recent began in June 2017. 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 Ontonagon's 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 4 violations for this system; none is health-based, and the most recent began in June 2017. For current results, consult the system's annual water quality report, EPA ECHO, or the MI state drinking water program.
Where can I find Ontonagon's water quality report?
As a community water system, Ontonagon 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 Ontonagon County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Mcmillan Township | Ontonagon | 391 | Community | Groundwater |
| Rockland Township | Ontonagon | 350 | Community | Groundwater |
| Bergland Township | Ontonagon | 210 | Community | Groundwater |
| Interior Township | Ontonagon | 200 | Community | Groundwater |
| North Coast Adventures Campground | Ontonagon | 180 | Transient non-community | Groundwater |
| Settlers Cooperative | Ontonagon | 150 | 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, “Ontonagon, PWSID MI0005030, Michigan”, https://aquacensus.com/water-systems/michigan/ontonagon-mi0005030 (data as of October 1, 2026).