ONTARIO, CITY OF
PWS ID: OR4100587 · ONTARIO, Oregon 97914
PFAS Detected
1 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.
Population Served
14,465
Total Violations
150
Health-Based Violations
1
Water Source
Surface Water
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 4,082
- County
- Malheur
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 144
- Treatment Tech Violations
- 1
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Surface Water Treatment Rule | MR | 16 | 2023 |
| Coliform (TCR) | MR | 12 | 2013 |
| Interim Enhanced Surface Water Treatment Rule | MR | 9 | 2023 |
| Total Haloacetic Acids (HAA5) | MR | 6 | 2015 |
| TTHM | MR | 6 | 2015 |
| Arsenic | MR | 4 | 2009 |
| Nitrate | MR | 3 | 2009 |
| Toxaphene | MR | 2 | 2008 |
| Dalapon | MR | 2 | 2008 |
| Glyphosate | MR | 2 | 2008 |
| Dinoseb | MR | 2 | 2008 |
| Hexachlorocyclopentadiene | MR | 2 | 2008 |
| Heptachlor | MR | 2 | 2008 |
| 2,4,5-TP | MR | 2 | 2008 |
| Total Polychlorinated Biphenyls (PCB) | MR | 2 | 2008 |
| HEXACHLOROBENZENE | MR | 2 | 2008 |
| BHC-GAMMA | MR | 2 | 2008 |
| Chlordane | MR | 2 | 2008 |
| Benzo(a)pyrene | MR | 2 | 2008 |
| Heptachlor epoxide | MR | 2 | 2008 |
| Methoxychlor | MR | 2 | 2008 |
| Diquat | MR | 2 | 2008 |
| Simazine | MR | 2 | 2008 |
| Carbofuran | MR | 2 | 2008 |
| Endrin | MR | 2 | 2008 |
| LASSO | MR | 2 | 2008 |
| Endothall | MR | 2 | 2008 |
| OXAMYL | MR | 2 | 2008 |
| Picloram | MR | 2 | 2008 |
| Di(2-ethylhexyl) phthalate | MR | 2 | 2008 |
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 4 of 120 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| PFHxS | 8/19/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFNA | 8/19/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFBS | 8/19/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHpS | 8/19/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 4:2 FTS | 8/19/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHpA | 8/19/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| NEtFOSAA | 8/19/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| NMeFOSAA | 8/19/2024 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| PFTA | 8/19/2024 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| PFTrDA | 8/19/2024 | <0.007 µg/L | 0.007 µg/L | Not Detected |
| PFPeS | 8/19/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| NFDHA | 8/19/2024 | <0.02 µg/L | 0.02 µg/L | Not Detected |
| PFEESA | 8/19/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFMBA | 8/19/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFPeA | 8/19/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 8:2 FTS | 8/19/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFOS | 8/19/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFUnA | 8/19/2024 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| PFOA | 8/19/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| lithium | 8/19/2024 | 37.1000 µg/L | 9 µg/L | Detected |
| PFDA | 8/19/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFDoA | 8/19/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFMPA | 8/19/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFHxA | 8/19/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 6:2 FTS | 8/19/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 11Cl-PF3OUdS | 8/19/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 9Cl-PF3ONS | 8/19/2024 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| ADONA | 8/19/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| HFPO-DA | 8/19/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFBA | 8/19/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 8:2 FTS | 5/6/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| NMeFOSAA | 5/6/2024 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| NEtFOSAA | 5/6/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFTrDA | 5/6/2024 | <0.007 µg/L | 0.007 µg/L | Not Detected |
| PFHxA | 5/6/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFTA | 5/6/2024 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| PFBS | 5/6/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHpA | 5/6/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHxS | 5/6/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| lithium | 5/6/2024 | 33.5000 µg/L | 9 µg/L | Detected |
| PFNA | 5/6/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFOS | 5/6/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFOA | 5/6/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFDA | 5/6/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFPeA | 5/6/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFDoA | 5/6/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHpS | 5/6/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 6:2 FTS | 5/6/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFPeS | 5/6/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| NFDHA | 5/6/2024 | <0.02 µg/L | 0.02 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.