Public water system · ID5420010
ActiveCastleford City of
At a glance
City of Castleford (PWSID ID5420010) is an active community water system in Twin Falls County, Idaho. It reports serving 275 people through 112 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, 3 are health-based, and the most recent began in December 2022.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
275
Service connections
112
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does City of Castleford compare with other water systems in Twin Falls County?
By EPA's size categories, City of Castleford is a very small system (500 people or fewer). Twin Falls County has 54 active public water systems. Its population served is well below the county average of 1,409 people per system, and accounts for 0.4% 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 City of Castleford 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. 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 City of Castleford?
EPA lists City of Castleford 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 City of Castleford have drinking water violations?
Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in December 2022. The violations listed here began between July 2008 and December 2022. By type: 8 monitoring and reporting, 3 contaminant level above the legal limit and 1 monitoring. The contaminant or rule involved most often is Arsenic (4 of them). EPA lists 7 as resolved, 4 as archived 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. 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. 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 |
|---|---|---|---|---|
| 2022-12-30 | Monitoring and reportingLead Consumer Notice · code 66 | Lead and Copper Rulecode 5000 | No | Unaddressed |
| 2019-10-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2019-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Archived |
| 2013-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Archived |
| 2009-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2009-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Arseniccode 1005 | Yes | Resolved |
| 2008-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
| 2008-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Resolved |
| 2008-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Arseniccode 1005 | No | Resolved |
| 2008-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2008-10-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 2008-07-01 | 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.
City of Castleford: frequently asked questions
Who runs City of Castleford?
City of Castleford (PWSID ID5420010) is a community water system owned by a local government. It is regulated by the ID state drinking water program.
How many people does City of Castleford serve?
City of Castleford reports serving 275 people through 112 service connections in Twin Falls County, Idaho.
Where does City of Castleford 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 City of Castleford have any drinking water violations?
Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in December 2022. 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 City of Castleford'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, 3 are health-based, and the most recent began in December 2022. For current results, consult the system's annual water quality report, EPA ECHO, or the ID state drinking water program.
Where can I find City of Castleford's water quality report?
As a community water system, City of Castleford 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 |
| Filer Water Works | Twin Falls | 2,858 | Community | Groundwater |
| Hansen City of | Twin Falls | 1,200 | Community | Groundwater |
| LDS Church Kimberly Sc | Twin Falls | 659 | 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, “Castleford City of, PWSID ID5420010, Idaho”, https://aquacensus.com/water-systems/idaho/castleford-city-of-id5420010 (data as of October 1, 2026).