Public water system · 085690004
ActiveArapahoe Comm Water System
At a glance
Arapahoe Comm Water System (PWSID 085690004) is an active community water system in Wyoming. It reports serving 4,100 people through 422 service connections. Its primary water source is groundwater, and EPA lists it as Native American-owned. 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
4,100
Service connections
422
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Arapahoe Comm Water System compare with other water systems in Wyoming?
By EPA's size categories, Arapahoe Comm Water System is a medium system (3,301 to 10,000 people). Across Wyoming, the 775 active systems average 838 people each. Nationally, the average active community water system reports serving 6,703 people, so Arapahoe Comm Water System is about 39% 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. Wyoming has 332 active community water systems, 43% of the state's 775 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 585 Wyoming systems (75%) list groundwater as their primary source.
Who owns and regulates Arapahoe Comm Water System?
EPA lists Arapahoe Comm Water System as Native American-owned. The EPA Region 08 is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act.
Does Arapahoe Comm Water System 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 September 2017 and January 2026. By type: 11 monitoring and reporting and 1 monitoring. The contaminant or rule involved most often is Nitrate-Nitrite (3 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 |
|---|---|---|---|---|
| 2026-01-14 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Resolved |
| 2024-10-09 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Resolved |
| 2020-04-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Radium-226code 4020 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Uraniumcode 4006 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Radium-228code 4030 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Radium (-226 and -228)code 4010 | No | Resolved |
| 2019-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitrate-Nitritecode 1038 | No | Resolved |
| 2019-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitrate-Nitritecode 1038 | No | Resolved |
| 2019-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitrate-Nitritecode 1038 | No | Resolved |
| 2017-09-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | 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.
Arapahoe Comm Water System: frequently asked questions
Who runs Arapahoe Comm Water System?
Arapahoe Comm Water System (PWSID 085690004) is a community water system Native American-owned. It is regulated by the EPA Region 08.
How many people does Arapahoe Comm Water System serve?
Arapahoe Comm Water System reports serving 4,100 people through 422 service connections in Wyoming.
Where does Arapahoe Comm Water System 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 Arapahoe Comm Water System 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 Arapahoe Comm Water System'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 January 2026. For current results, consult the system's annual water quality report, EPA ECHO, or the EPA Region 08.
Where can I find Arapahoe Comm Water System's water quality report?
As a community water system, Arapahoe Comm Water System 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 Wyoming
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Cheyenne Board of Public Utilities | Laramie | 64,165 | Community | Surface water |
| Casper, City of | Natrona | 59,000 | Community | Purchased surface water |
| Laramie, City of | Albany | 32,395 | Community | Surface water |
| Gillette, City of | Campbell | 32,222 | Community | Groundwater |
| Jackson, Town of | Teton | 24,760 | Community | Groundwater |
| Rock Springs, City of | Sweetwater | 24,000 | Community | Purchased surface water |
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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, “Arapahoe Comm Water System, PWSID 085690004, Wyoming”, https://aquacensus.com/water-systems/wyoming/arapahoe-comm-water-system-085690004 (data as of October 1, 2026).