Colusa Northern System
PWS ID: 090605046 · Colusa, 09 95932-4018
Population Served
67
Total Violations
385
Health-Based Violations
0
Water Source
Groundwater
System Details
- System Type
- Community
- Owner Type
- Native American
- Connections
- 13
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 149
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Nitrate | MR | 5 | 2004 |
| Consumer Confidence Rule | Other | 5 | 2005 |
| Coliform (TCR) | MR | 4 | 1996 |
| BHC-GAMMA | MR | 3 | 2004 |
| Methoxychlor | MR | 3 | 2004 |
| Toxaphene | MR | 3 | 2004 |
| Atrazine | MR | 3 | 2004 |
| LASSO | MR | 3 | 2004 |
| Heptachlor | MR | 3 | 2004 |
| Heptachlor epoxide | MR | 3 | 2004 |
| 2,4-D | MR | 3 | 2004 |
| 2,4,5-TP | MR | 3 | 2004 |
| Pentachlorophenol | MR | 3 | 2004 |
| Total Polychlorinated Biphenyls (PCB) | MR | 3 | 2004 |
| ETHYLENE DIBROMIDE | MR | 3 | 2004 |
| Xylenes, Total | MR | 3 | 2004 |
| Chlordane | MR | 3 | 2004 |
| Carbofuran | MR | 3 | 2004 |
| 1,2-DIBROMO-3-CHLOROPROPANE | MR | 3 | 2004 |
| Arsenic | MR | 2 | 2001 |
| Cadmium | MR | 2 | 2001 |
| Chromium | MR | 2 | 2001 |
| Fluoride | MR | 2 | 2001 |
| CYANIDE | MR | 2 | 2004 |
| Endrin | MR | 2 | 2004 |
| Dalapon | MR | 2 | 2004 |
| Diquat | MR | 2 | 2004 |
| Endothall | MR | 2 | 2004 |
| Glyphosate | MR | 2 | 2004 |
| OXAMYL | MR | 2 | 2004 |
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025.
This data is provided for informational purposes only.