UNALASKA WATER SYSTEM
PWS ID: AK2260309 · UNALASKA, Alaska 99685
Population Served
9,400
Total Violations
398
Health-Based Violations
3
Water Source
Surface Water
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 603
- County
- Aleutians West Census Area
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 288
- Treatment Tech Violations
- 3
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Surface Water Treatment Rule | MR | 12 | 2024 |
| Nitrate | MR | 11 | 2024 |
| Coliform (TCR) | MR | 9 | 2015 |
| Arsenic | MR | 8 | 2003 |
| Chlorine | MR | 8 | 2024 |
| Barium | MR | 7 | 1992 |
| Cadmium | MR | 7 | 1992 |
| Chromium | MR | 7 | 1992 |
| Selenium | MR | 7 | 1992 |
| Fluoride | MR | 7 | 1992 |
| Mercury | MR | 7 | 1992 |
| Methoxychlor | MR | 6 | 2001 |
| Toxaphene | MR | 6 | 2001 |
| 2,4,5-TP | MR | 6 | 2001 |
| 2,4-D | MR | 6 | 2001 |
| BHC-GAMMA | MR | 6 | 2001 |
| Endrin | MR | 6 | 2001 |
| p-Dichlorobenzene | MR | 5 | 1997 |
| Carbon tetrachloride | MR | 5 | 1997 |
| CHLOROBENZENE | MR | 5 | 1997 |
| Toluene | MR | 5 | 1997 |
| Tetrachloroethylene | MR | 5 | 1997 |
| Ethylbenzene | MR | 5 | 1997 |
| 1,1-Dichloroethylene | MR | 5 | 1997 |
| Trichloroethylene | MR | 5 | 1997 |
| 1,2-Dichloroethane | MR | 5 | 1997 |
| 1,1,2-Trichloroethane | MR | 5 | 1997 |
| 1,1,1-Trichloroethane | MR | 5 | 1997 |
| o-Dichlorobenzene | MR | 5 | 1997 |
| 1,2-Dichloropropane | MR | 5 | 1997 |
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 240 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| lithium | 7/10/2023 | <9 µg/L | 9 µg/L | Not Detected |
| PFOS | 6/19/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| HFPO-DA | 6/19/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| ADONA | 6/19/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 9Cl-PF3ONS | 6/19/2023 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| 11Cl-PF3OUdS | 6/19/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFUnA | 6/19/2023 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| PFHxA | 6/19/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFBS | 6/19/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHpA | 6/19/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFNA | 6/19/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFDA | 6/19/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFOA | 6/19/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFBA | 6/19/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| NEtFOSAA | 6/19/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFHxS | 6/19/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFTrDA | 6/19/2023 | <0.007 µg/L | 0.007 µg/L | Not Detected |
| PFHpS | 6/19/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFPeS | 6/19/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| NFDHA | 6/19/2023 | <0.02 µg/L | 0.02 µg/L | Not Detected |
| PFTA | 6/19/2023 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| PFDoA | 6/19/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 6:2 FTS | 6/19/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFEESA | 6/19/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFMBA | 6/19/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFPeA | 6/19/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFMPA | 6/19/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| 8:2 FTS | 6/19/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 4:2 FTS | 6/19/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| NMeFOSAA | 6/19/2023 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| PFTrDA | 6/13/2024 | <0.007 µg/L | 0.007 µg/L | Not Detected |
| PFTA | 6/13/2024 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| NEtFOSAA | 6/13/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| NMeFOSAA | 6/13/2024 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| lithium | 3/27/2023 | <9 µg/L | 9 µg/L | Not Detected |
| lithium | 3/27/2023 | <9 µg/L | 9 µg/L | Not Detected |
| lithium | 3/27/2023 | <9 µg/L | 9 µg/L | Not Detected |
| PFOS | 12/29/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| ADONA | 12/29/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFBS | 12/29/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHpA | 12/29/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHxS | 12/29/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFNA | 12/29/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| 8:2 FTS | 12/29/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| lithium | 12/29/2023 | <9 µg/L | 9 µg/L | Not Detected |
| NEtFOSAA | 12/29/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFTrDA | 12/29/2023 | <0.007 µg/L | 0.007 µg/L | Not Detected |
| PFTA | 12/29/2023 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| PFHpS | 12/29/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFPeS | 12/29/2023 | <0.004 µg/L | 0.004 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.