Public water system · NN0400821
ActiveTwin Arrows Navajo Casino Internal
At a glance
Twin Arrows Navajo Casino Internal (PWSID NN0400821) is an active non-transient non-community water system in Arizona. It reports serving 25 people through 1 service connection. Its primary water source is purchased 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 April 2023.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
25
Service connections
1
Primary source
GWP
Purchased groundwater
System type
NTNCWS
Non-transient non-community water system
System record
How does Twin Arrows Navajo Casino Internal compare with other water systems in Arizona?
By EPA's size categories, Twin Arrows Navajo Casino Internal is a very small system (500 people or fewer). Across Arizona, the 1,769 active systems average 4,369 people each. Nationally, the average active non-transient non-community water system reports serving 430 people, so Twin Arrows Navajo Casino Internal is well below that figure.
What does “non-transient non-community water system” mean?
A non-transient non-community water system regularly serves at least 25 of the same people for more than six months a year, but not where they live. Schools, factories, office buildings and hospitals with their own supply are typical examples. Arizona has 232 active non-transient non-community water systems, 13% of the state's 1,769 active systems. Purchased groundwater means the system buys groundwater from another public water system rather than drawing its own. 71 Arizona systems (4%) list purchased groundwater as their primary source.
Who owns and regulates Twin Arrows Navajo Casino Internal?
EPA lists Twin Arrows Navajo Casino Internal as Native American-owned. The NN state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act.
Does Twin Arrows Navajo Casino Internal 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 2023. The violations listed here began between May 2021 and April 2023. By type: 7 monitoring, 4 reporting and 1 monitoring and reporting. The contaminant or rule involved most often is Revised Total Coliform Rule (11 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 |
|---|---|---|---|---|
| 2023-04-01 | ReportingReport Sample Result/Fail Monitor (RTCR) · code 4B | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2022-04-01 | ReportingReport Sample Result/Fail Monitor (RTCR) · code 4B | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2022-02-01 | ReportingReport Sample Result/Fail Monitor (RTCR) · code 4B | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2022-01-01 | ReportingReport Sample Result/Fail Monitor (RTCR) · code 4B | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2021-11-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2021-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2021-10-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2021-09-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2021-08-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2021-07-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2021-06-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2021-05-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | 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.
Twin Arrows Navajo Casino Internal: frequently asked questions
Who runs Twin Arrows Navajo Casino Internal?
Twin Arrows Navajo Casino Internal (PWSID NN0400821) is a non-transient non-community water system Native American-owned. It is regulated by the NN state drinking water program.
How many people does Twin Arrows Navajo Casino Internal serve?
Twin Arrows Navajo Casino Internal reports serving 25 people through 1 service connection in Arizona.
Where does Twin Arrows Navajo Casino Internal get its water?
EPA SDWIS lists this system's primary water source as purchased groundwater. Purchased groundwater means the system buys groundwater from another public water system rather than drawing its own.
Does Twin Arrows Navajo Casino Internal 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 2023. 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 Twin Arrows Navajo Casino Internal'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 2023. For current results, consult EPA ECHO, or the NN state drinking water program.
Where can I find Twin Arrows Navajo Casino Internal's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Twin Arrows Navajo Casino Internal is a non-transient non-community water system, so it is not required to publish one; like every public water system, it must notify the people it serves about violations under EPA's public notification rules.
Other water systems in Arizona
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Phoenix City of | Maricopa | 1,695,000 | Community | Surface water |
| Tucson City of | Pima | 732,906 | Community | Groundwater |
| Mesa City of | Maricopa | 466,000 | Community | Surface water |
| Gilbert, Town of | Maricopa | 247,600 | Community | Surface water |
| Chandler City of | Maricopa | 247,328 | Community | Surface water |
| Scottsdale City of | Maricopa | 241,361 | Community | 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, “Twin Arrows Navajo Casino Internal, PWSID NN0400821, Arizona”, https://aquacensus.com/water-systems/arizona/twin-arrows-navajo-casino-internal-nn0400821 (data as of October 1, 2026).