Public water system · MI0000221
ActiveAnn Arbor Township
At a glance
Ann Arbor Township (PWSID MI0000221) is an active community water system in Washtenaw County, Michigan. It reports serving 1,338 people through 535 service connections. Its primary water source is purchased 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 December 2016.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,338
Service connections
535
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Ann Arbor Township compare with other water systems in Washtenaw County?
By EPA's size categories, Ann Arbor Township is a small system (501 to 3,300 people). Washtenaw County has 262 active public water systems. Its population served is about 17% above the county average of 1,147 people per system, and accounts for 0.4% of the 300,406 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 Ann Arbor Township 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. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 262 Michigan systems (2.5%) list purchased surface water as their primary source.
Who owns and regulates Ann Arbor Township?
EPA lists Ann Arbor Township 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. 16 of the 262 active systems in Washtenaw County (6.1%) are also owned by a local government.
Does Ann Arbor Township have drinking water violations?
EPA's records list 4 violations for this system; none is health-based, and the most recent began in December 2016. The violations listed here began between November 1992 and December 2016. By type: 3 monitoring and reporting and 1 public notice, recordkeeping or other. The contaminants or rules involved are Haloacetic acids (HAA5), Total trihalomethanes (TTHM), Consumer Confidence Rule 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 |
|---|---|---|---|---|
| 2016-12-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2016-12-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2001-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 1992-11-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | 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.
Ann Arbor Township: frequently asked questions
Who runs Ann Arbor Township?
Ann Arbor Township (PWSID MI0000221) is a community water system owned by a local government. It is regulated by the MI state drinking water program.
How many people does Ann Arbor Township serve?
Ann Arbor Township reports serving 1,338 people through 535 service connections in Washtenaw County, Michigan.
Where does Ann Arbor Township 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 Ann Arbor Township have any drinking water violations?
EPA's records list 4 violations for this system; none is health-based, and the most recent began in December 2016. 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 Ann Arbor Township'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 December 2016. For current results, consult the system's annual water quality report, EPA ECHO, or the MI state drinking water program.
Where can I find Ann Arbor Township's water quality report?
As a community water system, Ann Arbor Township 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 Washtenaw County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Ann Arbor | Washtenaw | 123,851 | Community | Surface water |
| Ypsilanti Community Utility Authority | Washtenaw | 53,988 | Community | Purchased surface water |
| Pittsfield Township | Washtenaw | 24,500 | Community | Purchased surface water |
| Saline | Washtenaw | 9,158 | Community | Groundwater |
| Scio Township | Washtenaw | 8,500 | Community | Purchased surface water |
| Milan | Washtenaw | 7,363 | 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, “Ann Arbor Township, PWSID MI0000221, Michigan”, https://aquacensus.com/water-systems/michigan/ann-arbor-township-mi0000221 (data as of October 1, 2026).