Oljato NTUA
PWS ID: NN4900224 · Ft Defiance, Navajo Nation 86504
Population Served
1,276
Total Violations
49
Health-Based Violations
3
Water Source
Groundwater
System Details
- System Type
- Community
- Owner Type
- Native American
- Connections
- 373
- School/Daycare
- No
- MCL Violations
- 3
- Monitoring Violations
- 36
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Antimony, Total | MCL | 3 | 2012 |
| Total Haloacetic Acids (HAA5) | MR | 3 | 2020 |
| Coliform (TCR) | MR | 3 | 2012 |
| TTHM | MR | 3 | 2020 |
| Stage 2 Disinfectants and Disinfection Byproducts Rule | MR | 2 | 2013 |
| DICHLOROMETHANE | MR | 1 | 2005 |
| Vinyl chloride | MR | 1 | 2005 |
| trans-1,2-Dichloroethylene | MR | 1 | 2005 |
| Carbon tetrachloride | MR | 1 | 2005 |
| 1,2-Dichloropropane | MR | 1 | 2005 |
| 1,1,2-Trichloroethane | MR | 1 | 2005 |
| Toluene | MR | 1 | 2005 |
| Ethylbenzene | MR | 1 | 2005 |
| Gross Alpha, Excl. Radon and U | MR | 1 | 2005 |
| Combined Uranium | MR | 1 | 2005 |
| o-Dichlorobenzene | MR | 1 | 2005 |
| 1,2-Dichloroethane | MR | 1 | 2005 |
| Revised Total Coliform Rule | Other | 1 | 2016 |
| Xylenes, Total | MR | 1 | 2005 |
| Nitrite | MR | 1 | 2010 |
| 1,2,4-Trichlorobenzene | MR | 1 | 2005 |
| 1,1-Dichloroethylene | MR | 1 | 2005 |
| Benzene | MR | 1 | 2005 |
| p-Dichlorobenzene | MR | 1 | 2005 |
| Trichloroethylene | MR | 1 | 2005 |
| CHLOROBENZENE | MR | 1 | 2005 |
| 1,1,1-Trichloroethane | MR | 1 | 2005 |
| Styrene | MR | 1 | 2005 |
| Tetrachloroethylene | MR | 1 | 2005 |
| cis-1,2-Dichloroethylene | MR | 1 | 2005 |
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025.
This data is provided for informational purposes only.