Public water system · IA1759048
ActivePlymouth Water Supply
At a glance
Plymouth Water Supply (PWSID IA1759048) is an active community water system in Cerro Gordo County, Iowa. It reports serving 378 people through 175 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, none is health-based, and the most recent began in November 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
378
Service connections
175
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Plymouth Water Supply compare with other water systems in Cerro Gordo County?
By EPA's size categories, Plymouth Water Supply is a very small system (500 people or fewer). Cerro Gordo County has 34 active public water systems, and Plymouth Water Supply is the 6th-largest of them by population served. Its population served is well below the county average of 1,173 people per system, and accounts for 0.9% of the 39,879 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 Plymouth Water Supply 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. 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 Plymouth Water Supply?
EPA lists Plymouth 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. 11 of the 34 active systems in Cerro Gordo County (32%) are also owned by a local government.
Does Plymouth Water Supply have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in November 2025. The violations listed here began between October 2018 and November 2025. By type: 9 monitoring and reporting and 3 public notice, recordkeeping or other. The contaminant or rule involved most often is Public Notice (3 of them). EPA lists 7 as resolved, 3 as unaddressed and 2 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. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement. 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 |
|---|---|---|---|---|
| 2025-11-24 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Unaddressed |
| 2025-11-24 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Unaddressed |
| 2025-08-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Archived |
| 2025-08-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Archived |
| 2025-07-25 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Unaddressed |
| 2024-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2022-12-01 | Monitoring and reportingLead Consumer Notice · code 66 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2021-06-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2018-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | 2,4-Dcode 2105 | No | Resolved |
| 2018-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Vinyl chloridecode 2976 | No | Resolved |
| 2018-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Dichloromethanecode 2964 | No | Resolved |
| 2018-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Carbon tetrachloridecode 2982 | No | Resolved |
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.
Plymouth Water Supply: frequently asked questions
Who runs Plymouth Water Supply?
Plymouth Water Supply (PWSID IA1759048) is a community water system owned by a local government. It is regulated by the IA state drinking water program.
How many people does Plymouth Water Supply serve?
Plymouth Water Supply reports serving 378 people through 175 service connections in Cerro Gordo County, Iowa.
Where does Plymouth 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 Plymouth Water Supply have any drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in November 2025. 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 Plymouth 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. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in November 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the IA state drinking water program.
Where can I find Plymouth Water Supply's water quality report?
As a community water system, Plymouth 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 Cerro Gordo County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Mason City Water Department | Cerro Gordo | 27,338 | Community | Groundwater |
| Clear Lake Water Department | Cerro Gordo | 7,687 | Community | Groundwater |
| Rockwell Water Supply | Cerro Gordo | 1,071 | Community | Groundwater |
| Ventura Water Works | Cerro Gordo | 716 | Community | Groundwater |
| Thornton Water Supply | Cerro Gordo | 400 | Community | Groundwater |
| Bell Harbor | Cerro Gordo | 352 | 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, “Plymouth Water Supply, PWSID IA1759048, Iowa”, https://aquacensus.com/water-systems/iowa/plymouth-water-supply-ia1759048 (data as of October 1, 2026).