MCHENRY
PWS ID: IL1110600 · MCHENRY, Illinois 60050
PFAS Detected
2 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.
Population Served
22,335
Total Violations
101
Health-Based Violations
4
Water Source
Groundwater
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 8,484
- County
- McHenry
- School/Daycare
- No
- MCL Violations
- 2
- Monitoring Violations
- 93
- Treatment Tech Violations
- 2
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Lead and Copper Rule | MR | 8 | 2025 |
| Vinyl chloride | MR | 4 | 2023 |
| o-Dichlorobenzene | MR | 4 | 2023 |
| 1,2-Dichloropropane | MR | 4 | 2023 |
| 1,1,2-Trichloroethane | MR | 4 | 2023 |
| Tetrachloroethylene | MR | 4 | 2023 |
| CHLOROBENZENE | MR | 4 | 2023 |
| Toluene | MR | 4 | 2023 |
| DICHLOROMETHANE | MR | 4 | 2023 |
| Xylenes, Total | MR | 4 | 2023 |
| Trichloroethylene | MR | 4 | 2023 |
| 1,1-Dichloroethylene | MR | 4 | 2023 |
| cis-1,2-Dichloroethylene | MR | 4 | 2023 |
| Benzene | MR | 4 | 2023 |
| Carbon tetrachloride | MR | 4 | 2023 |
| 1,2,4-Trichlorobenzene | MR | 4 | 2023 |
| p-Dichlorobenzene | MR | 4 | 2023 |
| Styrene | MR | 4 | 2023 |
| 1,2-Dichloroethane | MR | 4 | 2023 |
| Ethylbenzene | MR | 4 | 2023 |
| trans-1,2-Dichloroethylene | MR | 4 | 2023 |
| 1,1,1-Trichloroethane | MR | 4 | 2023 |
| Coliform (TCR) | MCL | 2 | 1996 |
| Lead and Copper Rule | TT | 2 | 1992 |
| Gross Alpha, Excl. Radon and U | MR | 1 | 1977 |
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 2 of 240 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| PFTA | 5/23/2023 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| NEtFOSAA | 5/23/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| NMeFOSAA | 5/23/2023 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| lithium | 5/23/2023 | <9 µg/L | 9 µg/L | Not Detected |
| PFTrDA | 5/23/2023 | <0.007 µg/L | 0.007 µg/L | Not Detected |
| 4:2 FTS | 5/23/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 6:2 FTS | 5/23/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| NFDHA | 5/23/2023 | <0.02 µg/L | 0.02 µg/L | Not Detected |
| 8:2 FTS | 5/23/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFPeA | 5/23/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFEESA | 5/23/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFPeS | 5/23/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFHpS | 5/23/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFTA | 5/23/2023 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| PFTrDA | 5/23/2023 | <0.007 µg/L | 0.007 µg/L | Not Detected |
| NMeFOSAA | 5/23/2023 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| PFBA | 5/23/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFMBA | 5/23/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| NEtFOSAA | 5/23/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| HFPO-DA | 5/23/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| ADONA | 5/23/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 9Cl-PF3ONS | 5/23/2023 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| 11Cl-PF3OUdS | 5/23/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFUnA | 5/23/2023 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| PFHxA | 5/23/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFDoA | 5/23/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFDA | 5/23/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFOA | 5/23/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFOS | 5/23/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFNA | 5/23/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFHxS | 5/23/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFBS | 5/23/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| lithium | 5/23/2023 | <9 µg/L | 9 µg/L | Not Detected |
| PFHpA | 5/23/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFMPA | 5/23/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFPeA | 5/23/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFMBA | 5/23/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFEESA | 5/23/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| NFDHA | 5/23/2023 | <0.02 µg/L | 0.02 µg/L | Not Detected |
| PFPeS | 5/23/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| 8:2 FTS | 5/23/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| HFPO-DA | 5/23/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 4:2 FTS | 5/23/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFTA | 5/23/2023 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| lithium | 5/23/2023 | <9 µg/L | 9 µg/L | Not Detected |
| NMeFOSAA | 5/23/2023 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| NEtFOSAA | 5/23/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFHpS | 5/23/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFDoA | 5/23/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHpA | 5/23/2023 | <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.