MODESTO, CITY OF
PWS ID: CA5010010 · MODESTO, California 95355
PFAS Detected
8 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.
Population Served
218,771
Total Violations
25
Health-Based Violations
21
Water Source
Surface Water
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 70,793
- County
- Stanislaus
- School/Daycare
- No
- MCL Violations
- 21
- Monitoring Violations
- 3
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MCL | 16 | 1996 |
| Nitrate | MCL | 4 | 2013 |
| Coliform (TCR) | MR | 3 | 2001 |
| Combined Uranium | MCL | 1 | 1993 |
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 68 of 2580 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| 6:2 FTS | 9/12/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFBS | 9/12/2024 | 0.0034 µg/L | 0.003 µg/L | Detected |
| PFHpA | 9/12/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHxS | 9/12/2024 | 0.0069 µg/L | 0.003 µg/L | Detected |
| PFNA | 9/12/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFOS | 9/12/2024 | 0.0046 µg/L | 0.004 µg/L | Detected |
| PFOA | 9/12/2024 | 0.0041 µg/L | 0.004 µg/L | Detected |
| PFDoA | 9/12/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHxA | 9/12/2024 | 0.0039 µg/L | 0.003 µg/L | Detected |
| PFUnA | 9/12/2024 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| 11Cl-PF3OUdS | 9/12/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 9Cl-PF3ONS | 9/12/2024 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| ADONA | 9/12/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFBA | 9/12/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 4:2 FTS | 9/12/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 8:2 FTS | 9/12/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFMPA | 9/12/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFPeA | 9/12/2024 | 0.0046 µg/L | 0.003 µg/L | Detected |
| PFMBA | 9/12/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFEESA | 9/12/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| NFDHA | 9/12/2024 | <0.02 µg/L | 0.02 µg/L | Not Detected |
| PFPeS | 9/12/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFHpS | 9/12/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFDA | 9/12/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| HFPO-DA | 9/12/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFNA | 8/28/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFDoA | 8/28/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFOA | 8/28/2024 | 0.0055 µg/L | 0.004 µg/L | Detected |
| PFOS | 8/28/2024 | 0.0063 µg/L | 0.004 µg/L | Detected |
| PFHxS | 8/28/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHpA | 8/28/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFBS | 8/28/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHxA | 8/28/2024 | 0.0030 µg/L | 0.003 µg/L | Detected |
| PFMBA | 8/28/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFUnA | 8/28/2024 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| PFHpS | 8/28/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFPeS | 8/28/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| NFDHA | 8/28/2024 | <0.02 µg/L | 0.02 µg/L | Not Detected |
| PFDA | 8/28/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFEESA | 8/28/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFPeA | 8/28/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFBA | 8/28/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 8:2 FTS | 8/28/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 4:2 FTS | 8/28/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 6:2 FTS | 8/28/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 11Cl-PF3OUdS | 8/28/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 9Cl-PF3ONS | 8/28/2024 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| PFMPA | 8/28/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| ADONA | 8/28/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| HFPO-DA | 8/28/2024 | <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.