UNION HILL WATER ASSOCIATION INC
PWS ID: WA5390260 · Redmond, Washington 98053
Population Served
8,720
Total Violations
312
Health-Based Violations
3
Water Source
Groundwater
System Details
- System Type
- Community
- Owner Type
- Private
- Connections
- 2,104
- County
- King
- School/Daycare
- No
- MCL Violations
- 3
- Monitoring Violations
- 306
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| 1,2,4-Trichlorobenzene | MR | 7 | 2005 |
| o-Dichlorobenzene | MR | 7 | 2005 |
| p-Dichlorobenzene | MR | 7 | 2005 |
| trans-1,2-Dichloroethylene | MR | 7 | 2005 |
| 1,2-Dichloroethane | MR | 7 | 2005 |
| 1,1,1-Trichloroethane | MR | 7 | 2005 |
| Carbon tetrachloride | MR | 7 | 2005 |
| 1,2-Dichloropropane | MR | 7 | 2005 |
| Tetrachloroethylene | MR | 7 | 2005 |
| Benzene | MR | 7 | 2005 |
| Ethylbenzene | MR | 7 | 2005 |
| Styrene | MR | 7 | 2005 |
| DICHLOROMETHANE | MR | 7 | 2005 |
| Toluene | MR | 7 | 2005 |
| Vinyl chloride | MR | 7 | 2005 |
| Trichloroethylene | MR | 7 | 2005 |
| 1,1-Dichloroethylene | MR | 7 | 2005 |
| cis-1,2-Dichloroethylene | MR | 7 | 2005 |
| CHLOROBENZENE | MR | 7 | 2005 |
| Pentachlorophenol | MR | 7 | 2005 |
| 1,1,2-Trichloroethane | MR | 7 | 2005 |
| Methoxychlor | MR | 6 | 2005 |
| Toxaphene | MR | 6 | 2005 |
| Hexachlorocyclopentadiene | MR | 6 | 2005 |
| Atrazine | MR | 6 | 2005 |
| LASSO | MR | 6 | 2005 |
| Heptachlor | MR | 6 | 2005 |
| Heptachlor epoxide | MR | 6 | 2005 |
| HEXACHLOROBENZENE | MR | 6 | 2005 |
| Benzo(a)pyrene | MR | 6 | 2005 |
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 60 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| PFTA | 3/21/2023 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| PFBS | 3/21/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| NEtFOSAA | 3/21/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFNA | 3/21/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFTrDA | 3/21/2023 | <0.007 µg/L | 0.007 µg/L | Not Detected |
| NFDHA | 3/21/2023 | <0.02 µg/L | 0.02 µg/L | Not Detected |
| PFPeS | 3/21/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFHpS | 3/21/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| lithium | 3/21/2023 | <9 µg/L | 9 µg/L | Not Detected |
| PFHpA | 3/21/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHxS | 3/21/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFBA | 3/21/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFMBA | 3/21/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFEESA | 3/21/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFMPA | 3/21/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| 8:2 FTS | 3/21/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| NMeFOSAA | 3/21/2023 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| 6:2 FTS | 3/21/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFPeA | 3/21/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| HFPO-DA | 3/21/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 9Cl-PF3ONS | 3/21/2023 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| 11Cl-PF3OUdS | 3/21/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFUnA | 3/21/2023 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| PFHxA | 3/21/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFDoA | 3/21/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFDA | 3/21/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| ADONA | 3/21/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFOS | 3/21/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| 4:2 FTS | 3/21/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFOA | 3/21/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| 9Cl-PF3ONS | 10/10/2023 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| 4:2 FTS | 10/10/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 6:2 FTS | 10/10/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFBA | 10/10/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| ADONA | 10/10/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| HFPO-DA | 10/10/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 8:2 FTS | 10/10/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFMPA | 10/10/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFPeA | 10/10/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFMBA | 10/10/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFEESA | 10/10/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 11Cl-PF3OUdS | 10/10/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFPeS | 10/10/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| lithium | 10/10/2023 | <9 µg/L | 9 µg/L | Not Detected |
| NFDHA | 10/10/2023 | <0.02 µg/L | 0.02 µg/L | Not Detected |
| PFDoA | 10/10/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHpS | 10/10/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFTA | 10/10/2023 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| PFTrDA | 10/10/2023 | <0.007 µg/L | 0.007 µg/L | Not Detected |
| NEtFOSAA | 10/10/2023 | <0.005 µg/L | 0.005 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.