Public water system · ID7190013
ActiveChallis City of
At a glance
City of Challis (PWSID ID7190013) is an active community water system in Custer County, Idaho. It reports serving 900 people through 566 service connections. Its primary water source is surface water, 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 January 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
900
Service connections
566
Primary source
SW
Surface water
System type
CWS
Community water system
System record
How does City of Challis compare with other water systems in Custer County?
By EPA's size categories, City of Challis is a small system (501 to 3,300 people). Custer County has 57 active public water systems, and City of Challis is the largest of them by population served. Its population served is about 8.8 times the county average of 102 people per system, and accounts for 15% of the 5,823 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 Challis 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. Surface water means the system draws its water from rivers, lakes, streams or reservoirs. 66 Idaho systems (3.4%) list surface water as their primary source.
Who owns and regulates City of Challis?
EPA lists City of Challis 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. 4 of the 57 active systems in Custer County (7%) are also owned by a local government.
Does City of Challis have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2026. The violations listed here began between April 2021 and January 2026. By type: 10 monitoring and reporting and 2 monitoring. The contaminant or rule involved most often is Carbon, total (5 of them). EPA lists 9 as resolved, 2 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 |
|---|---|---|---|---|
| 2026-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Unaddressed |
| 2024-09-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Carbon, totalcode 2920 | No | Resolved |
| 2024-07-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2023-10-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2023-10-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36 | Surface Water Treatment Rulecode 0200 | No | Archived |
| 2023-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2022-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Carbon, totalcode 2920 | No | Resolved |
| 2022-05-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36 | Surface Water Treatment Rulecode 0200 | No | Resolved |
| 2022-05-01 | Monitoring and reportingMonitoring, Turbidity (Enhanced SWTR) · code 38 | Interim Enhanced Surface Water Treatment Rulecode 0300 | No | Resolved |
| 2022-04-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Carbon, totalcode 2920 | No | Resolved |
| 2021-04-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Carbon, totalcode 2920 | No | Resolved |
| 2021-04-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Carbon, totalcode 2920 | 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.
City of Challis: frequently asked questions
Who runs City of Challis?
City of Challis (PWSID ID7190013) 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 Challis serve?
City of Challis reports serving 900 people through 566 service connections in Custer County, Idaho.
Where does City of Challis get its water?
EPA SDWIS lists this system's primary water source as surface water. Surface water means the system draws its water from rivers, lakes, streams or reservoirs.
Does City of Challis 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 January 2026. 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 Challis' 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 January 2026. 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 Challis' water quality report?
As a community water system, City of Challis 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 Custer County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Mackay City of | Custer | 566 | Community | Groundwater |
| Blm Joe T Fallini | Custer | 540 | Transient non-community | Groundwater |
| Usfs Fishook Well | Custer | 460 | Transient non-community | Groundwater |
| Usfs Glacier View Campground | Custer | 314 | Transient non-community | Groundwater |
| Mountain Village Lodge and Restaurant | Custer | 225 | Transient non-community | Groundwater |
| Sawtooth Luces | Custer | 200 | 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, “Challis City of, PWSID ID7190013, Idaho”, https://aquacensus.com/water-systems/idaho/challis-city-of-id7190013 (data as of October 1, 2026).