RYAN DAM WATER SYSTEM
PWS ID: MT0000046 · HELENA, Montana 59620-0901
Population Served
230
Total Violations
189
Health-Based Violations
23
Water Source
Groundwater
System Details
- System Type
- Community
- Owner Type
- Private
- Connections
- 14
- County
- Cascade
- School/Daycare
- No
- MCL Violations
- 20
- Monitoring Violations
- 160
- Treatment Tech Violations
- 3
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MCL | 20 | 2008 |
| Coliform (TCR) | MR | 17 | 2008 |
| Lead and Copper Rule | MR | 13 | 2012 |
| Groundwater Rule | MR | 8 | 2019 |
| Consumer Confidence Rule | Other | 5 | 2019 |
| E. COLI | MR | 4 | 2023 |
| Nitrate-Nitrite | MR | 3 | 2000 |
| Endrin | MR | 3 | 1999 |
| Methoxychlor | MR | 3 | 1999 |
| Toxaphene | MR | 3 | 1999 |
| Dalapon | MR | 3 | 1999 |
| Endothall | MR | 3 | 1999 |
| Di(2-ethylhexyl) adipate | MR | 3 | 1999 |
| Simazine | MR | 3 | 1999 |
| Di(2-ethylhexyl) phthalate | MR | 3 | 1999 |
| Dinoseb | MR | 3 | 1999 |
| Aldicarb sulfoxide | MR | 3 | 1999 |
| Carbofuran | MR | 3 | 1999 |
| Atrazine | MR | 3 | 1999 |
| 2,3,7,8-TCDD | MR | 3 | 1999 |
| 2,4-D | MR | 3 | 1999 |
| 2,4,5-TP | MR | 3 | 1999 |
| Benzo(a)pyrene | MR | 3 | 1999 |
| Pentachlorophenol | MR | 3 | 1999 |
| Total Polychlorinated Biphenyls (PCB) | MR | 3 | 1999 |
| Chlordane | MR | 3 | 1999 |
| TTHM | MR | 3 | 2023 |
| Total Haloacetic Acids (HAA5) | MR | 3 | 2023 |
| Aldicarb sulfone | MR | 3 | 1999 |
| ETHYLENE DIBROMIDE | MR | 3 | 1999 |
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025.
This data is provided for informational purposes only.