Public water system · IA5288021
ActiveTiffin Water Supply
At a glance
Tiffin Water Supply (PWSID IA5288021) is an active community water system in Johnson County, Iowa. It reports serving 7,577 people through 1,500 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 5 violations for this system; 2 are health-based, and the most recent began in June 2014.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
7,577
Service connections
1,500
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Tiffin Water Supply compare with other water systems in Johnson County?
By EPA's size categories, Tiffin Water Supply is a medium system (3,301 to 10,000 people). Johnson County has 125 active public water systems, and Tiffin Water Supply is the 5th-largest of them by population served. Its population served is about 5.5 times the county average of 1,384 people per system, and accounts for 4.4% of the 172,955 people reported by systems filed under the county. Across Iowa, the 1,828 active systems average 1,718 people each. Nationally, the average active community water system reports serving 6,703 people, so Tiffin Water Supply is about 13% above 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. Iowa has 1,084 active community water systems, 59% of the state's 1,828 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 1,502 Iowa systems (82%) list groundwater as their primary source.
Who owns and regulates Tiffin Water Supply?
EPA lists Tiffin Water Supply as owned by a local government. The IA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 12 of the 125 active systems in Johnson County (9.6%) are also owned by a local government.
Does Tiffin Water Supply have drinking water violations?
EPA's records list 5 violations for this system; 2 are health-based, and the most recent began in June 2014. The violations listed here began between January 1987 and June 2014. By type: 3 monitoring and reporting and 2 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (2 of them). EPA lists 5 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 |
|---|---|---|---|---|
| 2014-06-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2005-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2001-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2000-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Arseniccode 1005 | No | Resolved |
| 1987-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Combined Radium (-226 and -228)code 4010 | Yes | Resolved |
All 5 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.
Tiffin Water Supply: frequently asked questions
Who runs Tiffin Water Supply?
Tiffin Water Supply (PWSID IA5288021) is a community water system owned by a local government. It is regulated by the IA state drinking water program.
How many people does Tiffin Water Supply serve?
Tiffin Water Supply reports serving 7,577 people through 1,500 service connections in Johnson County, Iowa.
Where does Tiffin Water Supply 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 Tiffin Water Supply have any drinking water violations?
EPA's records list 5 violations for this system; 2 are health-based, and the most recent began in June 2014. 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 Tiffin Water Supply'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 5 violations for this system; 2 are health-based, and the most recent began in June 2014. For current results, consult the system's annual water quality report, EPA ECHO, or the IA state drinking water program.
Where can I find Tiffin Water Supply's water quality report?
As a community water system, Tiffin Water Supply 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 Johnson County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Iowa City Water Department | Johnson | 68,753 | Community | Surface water |
| University Water System | Johnson | 26,684 | Community | Surface water |
| North Liberty Water Supply | Johnson | 23,276 | Community | Groundwater |
| Coralville Muni Water System | Johnson | 22,318 | Community | Groundwater |
| Solon Water Dept | Johnson | 3,018 | Community | Groundwater |
| Lone Tree Muni Water System | Johnson | 1,357 | 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, “Tiffin Water Supply, PWSID IA5288021, Iowa”, https://aquacensus.com/water-systems/iowa/tiffin-water-supply-ia5288021 (data as of October 1, 2026).