CLARK COUNTY CONS PWSD 1
PWS ID: MO2024138 · WILLIAMSTOWN, Missouri 63473-0000
Population Served
7,140
Total Violations
14
Health-Based Violations
0
Water Source
Groundwater
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 3,188
- County
- Clark
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 13
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Revised Total Coliform Rule | MON | 4 | 2022 |
| Coliform (TCR) | MR | 3 | 2003 |
| Stage 2 Disinfectants and Disinfection Byproducts Rule | MR | 2 | 2008 |
| Consumer Confidence Rule | Other | 1 | 2019 |
| Total Haloacetic Acids (HAA5) | MR | 1 | 2008 |
| TTHM | MR | 1 | 2008 |
| Lead and Copper Rule | MR | 1 | 2023 |
| Gross Alpha, Excl. Radon and U | MR | 1 | 1994 |
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 60 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| PFTrDA | 8/15/2023 | <0.007 µg/L | 0.007 µg/L | Not Detected |
| NMeFOSAA | 8/15/2023 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| PFTA | 8/15/2023 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| NEtFOSAA | 8/15/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| lithium | 8/15/2023 | <9 µg/L | 9 µg/L | Not Detected |
| 9Cl-PF3ONS | 2/8/2023 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| NEtFOSAA | 2/8/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFTrDA | 2/8/2023 | <0.007 µg/L | 0.007 µg/L | Not Detected |
| PFTA | 2/8/2023 | <0.008 µg/L | 0.008 µg/L | Not Detected |
| PFHpS | 2/8/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFPeS | 2/8/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| NFDHA | 2/8/2023 | <0.02 µg/L | 0.02 µg/L | Not Detected |
| PFEESA | 2/8/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFMBA | 2/8/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFMPA | 2/8/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| 4:2 FTS | 2/8/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 6:2 FTS | 2/8/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFBA | 2/8/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| NMeFOSAA | 2/8/2023 | <0.006 µg/L | 0.006 µg/L | Not Detected |
| ADONA | 2/8/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFPeA | 2/8/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 11Cl-PF3OUdS | 2/8/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFUnA | 2/8/2023 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| PFHxA | 2/8/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFDoA | 2/8/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFDA | 2/8/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFOA | 2/8/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFOS | 2/8/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFNA | 2/8/2023 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFHxS | 2/8/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFHpA | 2/8/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFBS | 2/8/2023 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| lithium | 2/8/2023 | <9 µg/L | 9 µg/L | Not Detected |
| HFPO-DA | 2/8/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 8:2 FTS | 2/8/2023 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFMPA | 2/25/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| 9Cl-PF3ONS | 2/25/2024 | <0.002 µg/L | 0.002 µg/L | Not Detected |
| ADONA | 2/25/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| HFPO-DA | 2/25/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFBA | 2/25/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 6:2 FTS | 2/25/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 11Cl-PF3OUdS | 2/25/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| 8:2 FTS | 2/25/2024 | <0.005 µg/L | 0.005 µg/L | Not Detected |
| PFMBA | 2/25/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFPeA | 2/25/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFEESA | 2/25/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| PFPeS | 2/25/2024 | <0.004 µg/L | 0.004 µg/L | Not Detected |
| PFHpS | 2/25/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| 4:2 FTS | 2/25/2024 | <0.003 µg/L | 0.003 µg/L | Not Detected |
| NFDHA | 2/25/2024 | <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.