Mariano Lake-Pinedale-Church Rock NTUA
PWS ID: NN3500211 · Ft Defiance, Navajo Nation 86504
PFAS Detected
1 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.
Population Served
4,562
Total Violations
108
Health-Based Violations
7
Water Source
Groundwater
System Details
- System Type
- Community
- Owner Type
- Native American
- Connections
- 1,334
- School/Daycare
- No
- MCL Violations
- 7
- Monitoring Violations
- 79
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Revised Total Coliform Rule | MON | 12 | 2017 |
| Coliform (TCR) | MR | 8 | 2012 |
| Coliform (TCR) | MCL | 6 | 2005 |
| Total Haloacetic Acids (HAA5) | MR | 6 | 2020 |
| TTHM | MR | 6 | 2020 |
| Fluoride | MR | 4 | 2021 |
| Glyphosate | MR | 3 | 2013 |
| cis-1,2-Dichloroethylene | MR | 3 | 2008 |
| 1,2-DIBROMO-3-CHLOROPROPANE | MR | 3 | 2008 |
| ETHYLENE DIBROMIDE | MR | 3 | 2008 |
| o-Dichlorobenzene | MR | 3 | 2008 |
| p-Dichlorobenzene | MR | 3 | 2008 |
| trans-1,2-Dichloroethylene | MR | 3 | 2008 |
| Trichloroethylene | MR | 3 | 2008 |
| Endothall | MR | 3 | 2013 |
| 2,3,7,8-TCDD | MR | 3 | 2013 |
| Diquat | MR | 3 | 2013 |
| Total Polychlorinated Biphenyls (PCB) | MR | 3 | 2008 |
| 1,1-Dichloroethylene | MR | 3 | 2008 |
| DICHLOROMETHANE | MR | 3 | 2008 |
| 1,2-DIBROMO-3-CHLOROPROPANE | MCL | 1 | 2010 |
| Nitrite | MR | 1 | 2010 |
| Revised Total Coliform Rule | Other | 1 | 2016 |
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 10 of 300 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| lithium | 9/27/2023 | 38.0000 µg/L | 9 µg/L | Detected |
| NMeFOSAA | 9/27/2023 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| NEtFOSAA | 9/27/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFTrDA | 9/27/2023 | <0.007 µg/L | 0.007 µg/L | Not Detected |
| PFTA | 9/27/2023 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| PFTA | 6/20/2023 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| PFTrDA | 6/20/2023 | <0.007 µg/L | 0.007 µg/L | Not Detected |
| NEtFOSAA | 6/20/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| NMeFOSAA | 6/20/2023 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| ADONA | 5/17/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFBS | 5/17/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHpA | 5/17/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHxS | 5/17/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFNA | 5/17/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFOS | 5/17/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFOA | 5/17/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFDA | 5/17/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFDoA | 5/17/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHxA | 5/17/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFUnA | 5/17/2023 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| lithium | 5/17/2023 | 28.0000 µg/L | 9 µg/L | Detected |
| 9Cl-PF3ONS | 5/17/2023 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| NFDHA | 5/17/2023 | <0.02 µg/L | 0.02 µg/L | Not Detected |
| HFPO-DA | 5/17/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFBA | 5/17/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 6:2 FTS | 5/17/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 4:2 FTS | 5/17/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 8:2 FTS | 5/17/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFMPA | 5/17/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFPeA | 5/17/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFMBA | 5/17/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFEESA | 5/17/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFPeS | 5/17/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| 11Cl-PF3OUdS | 5/17/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFTA | 5/17/2023 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| PFHpS | 5/17/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| NMeFOSAA | 5/17/2023 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| PFTrDA | 5/17/2023 | <0.007 µg/L | 0.007 µg/L | Not Detected |
| NEtFOSAA | 5/17/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 4:2 FTS | 5/17/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 6:2 FTS | 5/17/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| HFPO-DA | 5/17/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFBA | 5/17/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 8:2 FTS | 5/17/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFMPA | 5/17/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFHpS | 5/17/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 11Cl-PF3OUdS | 5/17/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFPeS | 5/17/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFHpA | 5/17/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| ADONA | 5/17/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025.
PFAS data from EPA UCMR5 monitoring program (2023-2025).
This data is provided for informational purposes only.