ONTARIO WATERWORKS
PWS ID: WI6630259 · Ontario, Wisconsin 54651
Population Served
554
Total Violations
77
Health-Based Violations
52
Water Source
Groundwater
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 241
- County
- Vernon
- School/Daycare
- No
- MCL Violations
- 51
- Monitoring Violations
- 15
- Treatment Tech Violations
- 1
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MCL | 51 | 2006 |
| Coliform (TCR) | MR | 8 | 2009 |
| Chlorine | MR | 4 | 2009 |
| Revised Total Coliform Rule | MON | 3 | 2025 |
| Public Notice | Other | 1 | 2024 |
| LEAD AND COPPER RULE REVISIONS | TT | 1 | 2024 |
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025.
This data is provided for informational purposes only.