Toadlena Ntua
PWSID: NN3503028
This system has unresolved violations related to monitoring, reporting, or procedural requirements, but none involve contaminant levels exceeding EPA health limits.
This system has more violations on record than 92% of water systems in Arizona.
Violation trend: 10.0 per year over the last 5 years, similar to 11.6 per year in the previous 5.
System Details
| Population Served | 903 |
| Service Connections | 264 |
| Water Source | Groundwater |
| System Type | Community Water System |
| Owner | Native American |
| Status | Active |
| City | Ft Defiance |
| EPA ZIP on File | 86504 |
Areas Served
Lead & Copper Testing
| Contaminant | Level | EPA Action Level | Status |
|---|---|---|---|
| Lead (90th percentile) | 0.0020 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0010 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0010 mg/L | 0.015 mg/L | Below Action Level |
| Lead (90th percentile) | 0.0010 mg/L | 0.015 mg/L | Below Action Level |
2 Active Violations
| Contaminant | Violation | Date | Health-Based | Status |
|---|---|---|---|---|
| 7500 | Other | 2025-04-01 | Open | |
| 7500 | Other | 2024-10-01 | Open |
Violation History (120 total)
| Contaminant | Violation | Date | Health-Based | Status |
|---|---|---|---|---|
| 1005 | MCL Measured: 0.0127 MG/L (EPA limit: 0.010 mg/L) | 2025-07-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0117 MG/L (EPA limit: 0.010 mg/L) | 2025-04-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0126 MG/L (EPA limit: 0.010 mg/L) | 2025-01-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0127 MG/L (EPA limit: 0.010 mg/L) | 2024-10-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0127 MG/L (EPA limit: 0.010 mg/L) | 2024-10-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0136 MG/L (EPA limit: 0.010 mg/L) | 2024-07-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0136 MG/L (EPA limit: 0.010 mg/L) | 2024-07-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0136 MG/L (EPA limit: 0.010 mg/L) | 2024-07-01 | Yes | Acknowledged |
| 7500 | Other | 2024-07-01 | Returned to Compliance | |
| 7500 | Other | 2024-07-01 | Returned to Compliance | |
| 1005 | MCL Measured: 0.0149 MG/L (EPA limit: 0.010 mg/L) | 2024-04-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0149 MG/L (EPA limit: 0.010 mg/L) | 2024-04-01 | Yes | Acknowledged |
| 7500 | Other | 2024-04-01 | Returned to Compliance | |
| 7500 | Other | 2024-04-01 | Returned to Compliance | |
| 1005 | MCL Measured: 0.0143 MG/L (EPA limit: 0.010 mg/L) | 2024-01-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0143 MG/L (EPA limit: 0.010 mg/L) | 2024-01-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0151 MG/L (EPA limit: 0.010 mg/L) | 2023-10-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0151 MG/L (EPA limit: 0.010 mg/L) | 2023-10-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0145 MG/L (EPA limit: 0.010 mg/L) | 2023-07-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0145 MG/L (EPA limit: 0.010 mg/L) | 2023-07-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0145 MG/L (EPA limit: 0.010 mg/L) | 2023-07-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0135 MG/L (EPA limit: 0.010 mg/L) | 2023-04-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0135 MG/L (EPA limit: 0.010 mg/L) | 2023-04-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0135 MG/L (EPA limit: 0.010 mg/L) | 2023-04-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0133 MG/L (EPA limit: 0.010 mg/L) | 2023-01-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0133 MG/L (EPA limit: 0.010 mg/L) | 2023-01-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0133 MG/L (EPA limit: 0.010 mg/L) | 2023-01-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0128 MG/L (EPA limit: 0.010 mg/L) | 2022-10-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0128 MG/L (EPA limit: 0.010 mg/L) | 2022-10-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0115 MG/L (EPA limit: 0.010 mg/L) | 2022-07-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0115 MG/L (EPA limit: 0.010 mg/L) | 2022-07-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0115 MG/L (EPA limit: 0.010 mg/L) | 2022-07-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0119 MG/L (EPA limit: 0.010 mg/L) | 2022-04-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0119 MG/L (EPA limit: 0.010 mg/L) | 2022-04-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0119 MG/L (EPA limit: 0.010 mg/L) | 2022-04-01 | Yes | Acknowledged |
| 7500 | Other | 2022-04-01 | Returned to Compliance | |
| 7500 | Other | 2022-04-01 | Returned to Compliance | |
| 7500 | Other | 2022-04-01 | Returned to Compliance | |
| 1005 | MCL Measured: 0.0135 MG/L (EPA limit: 0.010 mg/L) | 2022-01-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0135 MG/L (EPA limit: 0.010 mg/L) | 2022-01-01 | Yes | Acknowledged |
| 1005 | MR | 2022-01-01 | Major | Returned to Compliance |
| 1005 | MR | 2022-01-01 | Major | Returned to Compliance |
| 1052 | MR | 2022-01-01 | Major | Acknowledged |
| 1052 | MR | 2022-01-01 | Major | Acknowledged |
| 1005 | MCL Measured: 0.0157 MG/L (EPA limit: 0.010 mg/L) | 2021-10-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0157 MG/L (EPA limit: 0.010 mg/L) | 2021-10-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0175 MG/L (EPA limit: 0.010 mg/L) | 2021-07-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0175 MG/L (EPA limit: 0.010 mg/L) | 2021-07-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0178 MG/L (EPA limit: 0.010 mg/L) | 2021-04-01 | Yes | Acknowledged |
| 1005 | MCL Measured: 0.0178 MG/L (EPA limit: 0.010 mg/L) | 2021-04-01 | Yes | Acknowledged |
Showing 50 of 118 historical violations.
Understanding This Water System's Record
Toadlena Ntua is a community water system water system that draws from groundwater sources and serves a population of 903 in Ft Defiance, Arizona. This page shows its complete compliance history as reported to the EPA's Safe Drinking Water Information System (SDWIS), the federal database that tracks every public water system in the United States.
What Do These Violations Mean?
Health-based violations mean the system exceeded an EPA maximum contaminant level (MCL) or failed to provide required treatment. These indicate potential health risks from contaminants like lead, arsenic, bacteria, nitrates, or disinfection byproducts. Non-health-based violations involve monitoring, reporting, or procedural requirements — the system missed a testing deadline or failed to notify customers, but contaminant levels were not necessarily unsafe.
What Should You Do?
Your water utility is required to publish an annual Consumer Confidence Report (CCR) that details test results and any violations. If your system has active health-based violations, consider a certified water filter rated for the specific contaminants involved. The contaminant guides on this site explain health risks and filter options for common pollutants. For the most current results, contact your water utility directly — EPA data can lag weeks or months behind real-time testing.