Water Quality: Great Falls, MT
18 water systems • 65,624 people served
Multiple Health ViolationsWater Quality Summary
Great Falls is served by 18 public water systems with a combined service population of 65,624 people, and has 739 EPA Safe Drinking Water Act violations on record. Critically, 19 of those are health-based violations, meaning one or more contaminants were detected above EPA-established safe levels — a serious public health concern. Great Falls's violation count is 606% above the national average for Montana. Contaminants associated with violations include Barium, Chlorine Dioxide, Disinfection Byproducts, E. coli, Total Haloacetic Acids (HAA5).
Contaminants Found
Increases blood pressure and causes cardiovascular effects with long-term exposure.
Common source: Natural rock deposits, oil drilling operations, coal power plant waste
EPA limit: 2 mg/L
Can cause anemia in infants and young children; may cause nervous system effects at high levels.
Common source: Water treatment disinfectant used to control taste, odor, and microorganisms
EPA limit: 0.8 mg/L
Broad category of chemicals formed during disinfection, associated with increased cancer risk and adverse reproductive effects.
Common source: Reaction of disinfectants (chlorine, ozone, chloramines) with organic matter
Causes gastrointestinal illness; certain strains (e.g., O157:H7) can cause severe kidney failure and death.
Common source: Fecal contamination from humans or animals entering the water supply
EPA limit: Zero (no E. coli permitted in drinking water)
Haloacetic acids are associated with increased cancer risk and potential reproductive and developmental effects.
Common source: Reaction of chlorine disinfectants with organic matter in treated water
EPA limit: 0.060 mg/L (60 ppb)
Water Systems Serving Great Falls
| System Name | PWSID | Source | Population | Violations |
|---|---|---|---|---|
| GREAT FALLS CITY OF | MT0000525 | Surface Water | 60,000 | 5 |
| SUN PRAIRIE VILLAGE COUNTY | MT0000521 | Groundwater | 1,800 | 56 |
| PRAIRIE WATER COMPANY | MT0003539 | Surface Water | 1,000 | 34 |
| GORE HILL COUNTY WATER DIST | MT0000232 | Groundwater | 500 | 101 |
| HOMESTEAD ACRES COUNTY WATER AND SEWER | MT0000526 | Groundwater | 500 | 16 |
| HIGHWOOD MOBILE HOME PARK | MT0004681 | Surface Water | 400 | 6 |
| SUN PRAIRIE WATER DISTRICT | MT0000571 | Groundwater | 350 | 16 |
| GREAT FALLS RV PARK | MT0000027 | Surface Water | 274 | 0 |
| SOUTH WIND WATER AND SEWER DISTRICT | MT0000025 | Groundwater | 200 | 79 |
| PLEASANT PARK COMMUNITY INC | MT0000028 | Groundwater | 125 | 230 |
| BIG BEND RANCH SUBDIVISION | MT0004261 | Groundwater | 100 | 79 |
| SPRING TREE RIDGE | MT0004419 | Groundwater | 80 | 102 |
| GRASSLAND COLONY | MT0004832 | Groundwater | 80 | 0 |
| PARK GARDEN ESTATES | MT0000050 | Groundwater | 50 | 9 |
| WINDY ACRES WUA | MT0002806 | Groundwater | 50 | 4 |
| COBBLESTONE COURT | MT0004831 | Surface Water | 50 | 0 |
| BIG SKY MOBILE HOME PARK | MT0004683 | Surface Water | 40 | 2 |
| HIGH PLAINS H2O LLC | MT0005192 | Surface Water | 25 | 0 |
Concerned About Your Water?
A home water filter can remove common contaminants. NSF-certified filters are tested against EPA standards.
Consider a reverse osmosis system for comprehensive filtration or a carbon filter for basic improvement.
Other Cities in Montana
Data Sources
Drinking water violation data from the EPA Safe Drinking Water Information System (SDWIS). Data includes all recorded violations for active community water systems.