Public water system · OK3002004
ActiveArapaho
At a glance
Arapaho (PWSID OK3002004) is an active community water system in Custer County, Oklahoma. It reports serving 748 people through 463 service connections. Its primary water source is purchased 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 April 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
748
Service connections
463
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Arapaho compare with other water systems in Custer County?
By EPA's size categories, Arapaho is a small system (501 to 3,300 people). Custer County has 11 active public water systems, and Arapaho is the 5th-largest of them by population served. Its population served is about 66% below the county average of 2,181 people per system, and accounts for 3.1% of the 23,986 people reported by systems filed under the county. Across Oklahoma, the 1,254 active systems average 2,907 people each. Nationally, the average active community water system reports serving 6,703 people, so Arapaho 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. Oklahoma has 864 active community water systems, 69% of the state's 1,254 active systems. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 299 Oklahoma systems (24%) list purchased surface water as their primary source.
Who owns and regulates Arapaho?
EPA lists Arapaho as owned by a local government. The OK state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 7 of the 11 active systems in Custer County (64%) are also owned by a local government.
Does Arapaho have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in April 2025. The violations listed here began between April 2023 and April 2025. By type: 8 monitoring and reporting and 4 monitoring. The contaminant or rule involved most often is Revised Total Coliform Rule (4 of them). EPA lists 12 as resolved. 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.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2025-04-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2025-04-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chloraminecode 1006 | No | Resolved |
| 2025-01-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2025-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chloraminecode 1006 | No | Resolved |
| 2024-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2024-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2023-11-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2023-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chloraminecode 1006 | No | Resolved |
| 2023-06-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2023-04-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2023-04-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2023-04-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chloraminecode 1006 | 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.
Arapaho: frequently asked questions
Who runs Arapaho?
Arapaho (PWSID OK3002004) is a community water system owned by a local government. It is regulated by the OK state drinking water program.
How many people does Arapaho serve?
Arapaho reports serving 748 people through 463 service connections in Custer County, Oklahoma.
Where does Arapaho get its water?
EPA SDWIS lists this system's primary water source as purchased surface water. Purchased surface water means the system buys surface water from another public water system rather than drawing its own.
Does Arapaho 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 April 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 Arapaho'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 April 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the OK state drinking water program.
Where can I find Arapaho's water quality report?
As a community water system, Arapaho 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 |
|---|---|---|---|---|
| Weatherford | Custer | 10,833 | Community | Groundwater |
| Clinton | Custer | 8,883 | Community | Surface water |
| Thomas | Custer | 1,238 | Community | Groundwater |
| Custer County Rwd #3 | Custer | 960 | Community | Groundwater |
| Frontier Development Auth | Custer | 437 | Community | Purchased surface water |
| Custer City Pws | Custer | 393 | 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, “Arapaho, PWSID OK3002004, Oklahoma”, https://aquacensus.com/water-systems/oklahoma/arapaho-ok3002004 (data as of October 1, 2026).