Public water system · ID5420021
ActiveFiler Water Works
At a glance
Filer Water Works (PWSID ID5420021) is an active community water system in Twin Falls County, Idaho. It reports serving 2,858 people through 975 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, 4 are health-based, and the most recent began in July 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
2,858
Service connections
975
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Filer Water Works compare with other water systems in Twin Falls County?
By EPA's size categories, Filer Water Works is a small system (501 to 3,300 people). Twin Falls County has 54 active public water systems, and Filer Water Works is the 4th-largest of them by population served. Its population served is about twice the county average of 1,409 people per system, and accounts for 3.8% of the 76,088 people reported by systems filed under the county. Across Idaho, the 1,961 active systems average 899 people each. Nationally, the average active community water system reports serving 6,703 people, so Filer Water Works is about 57% 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. Idaho has 765 active community water systems, 39% of the state's 1,961 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 1,861 Idaho systems (95%) list groundwater as their primary source.
Who owns and regulates Filer Water Works?
EPA lists Filer Water Works as owned by a local government. The ID 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 54 active systems in Twin Falls County (30%) are also owned by a local government.
Does Filer Water Works have drinking water violations?
Of the 12 most recent violations in EPA's records, 4 are health-based, and the most recent began in July 2025. The violations listed here began between July 2020 and July 2025. By type: 5 monitoring and reporting, 4 contaminant level above the legal limit, 2 reporting and 1 monitoring. The contaminant or rule involved most often is Arsenic (4 of them). EPA lists 11 as resolved and 1 as unaddressed. 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.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2025-07-02 | ReportingNotification, Known or Potential LSL · code 4H | Lead and Copper Rule Revisionscode 5200 | No | Unaddressed |
| 2025-07-02 | ReportingNotification, Known or Potential LSL · code 4H | Lead and Copper Rule Revisionscode 5200 | No | Resolved |
| 2025-04-01 | Monitoring and reportingLead Consumer Notice · code 66 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2023-04-09 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Resolved |
| 2022-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2022-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2021-09-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2021-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2021-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2021-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2020-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2020-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | 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.
Filer Water Works: frequently asked questions
Who runs Filer Water Works?
Filer Water Works (PWSID ID5420021) is a community water system owned by a local government. It is regulated by the ID state drinking water program.
How many people does Filer Water Works serve?
Filer Water Works reports serving 2,858 people through 975 service connections in Twin Falls County, Idaho.
Where does Filer Water Works 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 Filer Water Works have any drinking water violations?
Of the 12 most recent violations in EPA's records, 4 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 Filer Water Works' 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, 4 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 ID state drinking water program.
Where can I find Filer Water Works' water quality report?
As a community water system, Filer Water Works 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 Twin Falls County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Twin Falls City of | Twin Falls | 56,121 | Community | Groundwater |
| Kimberly City of | Twin Falls | 5,359 | Community | Groundwater |
| Buhl City of | Twin Falls | 4,518 | Community | Groundwater |
| Hansen City of | Twin Falls | 1,200 | Community | Groundwater |
| LDS Church Kimberly Sc | Twin Falls | 659 | Transient non-community | Groundwater |
| Amalgamated Sugar Twin Falls | Twin Falls | 460 | Non-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, “Filer Water Works, PWSID ID5420021, Idaho”, https://aquacensus.com/water-systems/idaho/filer-water-works-id5420021 (data as of October 1, 2026).