Public water system · IA1528010
ActiveGriswold Water Supply
At a glance
Griswold Water Supply (PWSID IA1528010) is an active community water system in Cass County, Iowa. It reports serving 1,008 people through 543 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, 2 are health-based, and the most recent began in July 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,008
Service connections
543
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Griswold Water Supply compare with other water systems in Cass County?
By EPA's size categories, Griswold Water Supply is a small system (501 to 3,300 people). Cass County has 15 active public water systems, and Griswold Water Supply is the 2nd-largest of them by population served. Its population served is about 38% above the county average of 732 people per system, and accounts for 9.2% of the 10,975 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 Griswold 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 Griswold Water Supply?
EPA lists Griswold 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. 8 of the 15 active systems in Cass County (53%) are also owned by a local government.
Does Griswold Water Supply have drinking water violations?
Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in July 2025. The violations listed here began between October 1988 and July 2025. By type: 10 monitoring and reporting and 2 contaminant level above the legal limit. The contaminant or rule involved most often is Nitrate (6 of them). EPA lists 7 as resolved and 5 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 |
|---|---|---|---|---|
| 2025-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Archived |
| 2025-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Archived |
| 2024-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Archived |
| 2024-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Archived |
| 2005-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 1998-05-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1998-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Resolved |
| 1995-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Resolved |
| 1992-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 1992-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 1988-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 1988-10-01 | Monitoring and reportingMonitoring, Check/Repeat/Confirmation · code 04 | Nitratecode 1040 | No | 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.
Griswold Water Supply: frequently asked questions
Who runs Griswold Water Supply?
Griswold Water Supply (PWSID IA1528010) is a community water system owned by a local government. It is regulated by the IA state drinking water program.
How many people does Griswold Water Supply serve?
Griswold Water Supply reports serving 1,008 people through 543 service connections in Cass County, Iowa.
Where does Griswold 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 Griswold Water Supply have any drinking water violations?
Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in July 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 Griswold 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, 2 are health-based, and the most recent began in July 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 Griswold Water Supply's water quality report?
As a community water system, Griswold 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 Cass County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Atlantic Municipal Utilities | Cass | 7,252 | Community | Groundwater |
| Anita Municipal Utilities | Cass | 972 | Community | Groundwater |
| Massena Water Supply | Cass | 364 | Community | Groundwater |
| Lewis Water Supply | Cass | 357 | Community | Groundwater |
| Cumberland Water Supply | Cass | 266 | Community | Groundwater |
| Hitchcock House | Cass | 216 | 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, “Griswold Water Supply, PWSID IA1528010, Iowa”, https://aquacensus.com/water-systems/iowa/griswold-water-supply-ia1528010 (data as of October 1, 2026).