Water Quality in GREAT FALLS, MT (59405)
EPA violation data for public water systems serving ZIP code 59405.
89
Total Violations
13
Health-Based
76
Monitoring / Reporting
85
Resolved
What does this mean?
85 of 89 violations have been resolved. 13 are health-based violations, meaning contaminant levels exceeded federal safety limits. The remaining 76 are monitoring or reporting violations (missed testing deadlines or late paperwork — not necessarily a water quality issue). Not all violations mean your water is unsafe. The EPA requires reporting even for minor administrative issues.
Violations Detail (89 total)
| Contaminant | Category | MCL Limit | Measured | Date | Status | Health Effects |
|---|---|---|---|---|---|---|
| Revised Total Coliform Rule | Health-Based | N/A | N/A | Dec 1, 2025 | Active | N/A |
| Revised Total Coliform Rule | Health-Based | N/A | N/A | Dec 1, 2025 | Active | N/A |
| Lead and Copper Rule | Monitoring | N/A | N/A | Sep 28, 2025 | Active | N/A |
| Groundwater Rule | Health-Based | N/A | N/A | Jul 31, 2025 | Resolved | N/A |
| Groundwater Rule | Health-Based | N/A | N/A | Jul 31, 2025 | Resolved | N/A |
| Groundwater Rule | Health-Based | N/A | N/A | Jul 31, 2025 | Resolved | N/A |
| Groundwater Rule | Health-Based | N/A | N/A | Jul 31, 2025 | Resolved | N/A |
| Lead and Copper Rule | Monitoring | N/A | N/A | Jul 17, 2025 | Resolved | N/A |
| Lead and Copper Rule | Monitoring | N/A | N/A | Jul 17, 2025 | Resolved | N/A |
| Lead and Copper Rule | Monitoring | N/A | N/A | Jul 17, 2025 | Resolved | N/A |
Lead & Copper Levels
Violation Timeline
2025(29)
Revised Total Coliform Rule
2A
Revised Total Coliform Rule
2A
Lead and Copper Rule
66
Groundwater Rule
41
Groundwater Rule
41
Groundwater Rule
41
Groundwater Rule
41
Lead and Copper Rule
52
Lead and Copper Rule
52
Lead and Copper Rule
52
Revised Total Coliform Rule
3A
Revised Total Coliform Rule
3A
Revised Total Coliform Rule
3A
Consumer Confidence Rule
71
Consumer Confidence Rule
71
Revised Total Coliform Rule
1A
Revised Total Coliform Rule
1A
Revised Total Coliform Rule
1A
Revised Total Coliform Rule
1A
Revised Total Coliform Rule
3A
Revised Total Coliform Rule
3A
Revised Total Coliform Rule
3A
E. COLI
34
E. COLI
34
E. COLI
34
E. COLI
34
Revised Total Coliform Rule
3A
Revised Total Coliform Rule
3A
Revised Total Coliform Rule
3A
2024(18)
Nitrate-Nitrite
03
Nitrate-Nitrite
03
Nitrate-Nitrite
03
Nitrite
03
Nitrite
03
Lead and Copper Rule
66
Revised Total Coliform Rule
3A
Revised Total Coliform Rule
3A
Revised Total Coliform Rule
3A
Nitrate-Nitrite
03
Nitrate-Nitrite
03
Nitrate-Nitrite
03
Lead and Copper Rule
57
Lead and Copper Rule
57
Lead and Copper Rule
57
Revised Total Coliform Rule
3A
Revised Total Coliform Rule
3A
Revised Total Coliform Rule
3A
How Does This Compare?
GREAT FALLS (59405) has 89 recorded violations, including 13 health-based. 4 remain unresolved. Consider testing your tap water independently for added peace of mind.
Recommended Water Filters
Based on the contaminants detected in your area, these filter types may help improve your water quality.
Reverse Osmosis System
Highly effective at removing heavy metals, dissolved solids, and a wide range of contaminants. Recommended for homes with lead or arsenic concerns.
Targets:Lead, Copper, Arsenic, Mercury, Cadmium
Look for:NSF/ANSI 58 certified
UV Water Purifier
Uses ultraviolet light to neutralize bacteria, viruses, and parasites without chemicals. Ideal for homes with microbial contamination concerns.
Targets:E. coli, Coliform, Giardia, Cryptosporidium
Look for:NSF/ANSI 55 (Class A) certified
Always look for filters certified by NSF International for the specific contaminants you want to remove.