MASON CITY WATER DEPARTMENT
PWS ID: IA1750048 · MASON CITY, Iowa 50401
PFAS Detected
1 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.
Population Served
27,338
Total Violations
647
Health-Based Violations
68
Water Source
Groundwater
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 19,000
- County
- Cerro Gordo
- School/Daycare
- No
- MCL Violations
- 68
- Monitoring Violations
- 429
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Combined Radium (-226 and -228) | Other | 123 | 2003 |
| Combined Radium (-226 and -228) | MCL | 43 | 2004 |
| Coliform (TCR) | MCL | 25 | 2012 |
| Consumer Confidence Rule | Other | 17 | 2004 |
| Carbon tetrachloride | MR | 12 | 1995 |
| p-Dichlorobenzene | MR | 12 | 1995 |
| 1,1-Dichloroethylene | MR | 12 | 1995 |
| trans-1,2-Dichloroethylene | MR | 12 | 1995 |
| DICHLOROMETHANE | MR | 12 | 1995 |
| 1,2-Dichloropropane | MR | 12 | 1995 |
| CHLOROBENZENE | MR | 12 | 1995 |
| 1,2,4-Trichlorobenzene | MR | 12 | 1995 |
| Trichloroethylene | MR | 12 | 1995 |
| Xylenes, Total | MR | 12 | 1995 |
| LASSO | MR | 12 | 1995 |
| Benzo(a)pyrene | MR | 12 | 1995 |
| 2,4-D | MR | 12 | 1995 |
| Dalapon | MR | 12 | 1995 |
| Di(2-ethylhexyl) adipate | MR | 12 | 1995 |
| Di(2-ethylhexyl) phthalate | MR | 12 | 1995 |
| Pentachlorophenol | MR | 12 | 1995 |
| Simazine | MR | 12 | 1995 |
| 2,4,5-TP | MR | 12 | 1995 |
| cis-1,2-Dichloroethylene | MR | 12 | 1995 |
| Ethylbenzene | MR | 12 | 1995 |
| Styrene | MR | 12 | 1995 |
| Tetrachloroethylene | MR | 12 | 1995 |
| Toluene | MR | 12 | 1995 |
| Atrazine | MR | 12 | 1995 |
| Dinoseb | MR | 12 | 1995 |
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 2 of 60 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| NEtFOSAA | 7/17/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 8:2 FTS | 7/17/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| lithium | 7/17/2024 | 92.0000 µg/L | 9 µg/L | Detected |
| PFMBA | 7/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| NMeFOSAA | 7/17/2024 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| 6:2 FTS | 7/17/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFTA | 7/17/2024 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| PFHpS | 7/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFPeS | 7/17/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFTrDA | 7/17/2024 | <0.007 µg/L | 0.007 µg/L | Not Detected |
| PFEESA | 7/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFPeA | 7/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFOS | 7/17/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFNA | 7/17/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFHxS | 7/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHpA | 7/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFBS | 7/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 11Cl-PF3OUdS | 7/17/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFDoA | 7/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| NFDHA | 7/17/2024 | <0.02 µg/L | 0.02 µg/L | Not Detected |
| PFMPA | 7/17/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFUnA | 7/17/2024 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| 9Cl-PF3ONS | 7/17/2024 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| ADONA | 7/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFDA | 7/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| HFPO-DA | 7/17/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFBA | 7/17/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFOA | 7/17/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| 4:2 FTS | 7/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHxA | 7/17/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| HFPO-DA | 1/10/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFPeA | 1/10/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 6:2 FTS | 1/10/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 8:2 FTS | 1/10/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFMPA | 1/10/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFBA | 1/10/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFMBA | 1/10/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFEESA | 1/10/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFPeS | 1/10/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFHpS | 1/10/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| ADONA | 1/10/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| NEtFOSAA | 1/10/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFOS | 1/10/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFTrDA | 1/10/2024 | <0.007 µg/L | 0.007 µg/L | Not Detected |
| PFTA | 1/10/2024 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| NMeFOSAA | 1/10/2024 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| PFHxS | 1/10/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 4:2 FTS | 1/10/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| lithium | 1/10/2024 | 80.0000 µg/L | 9 µg/L | Detected |
| NFDHA | 1/10/2024 | <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.