D36/100
Great Falls Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 61,800 residents · Montana
What's In Great Falls's Tap Water?
76
Contaminants Tested
0
Exceed EPA Limits
1
Above EPA Goals
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.008 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2019.
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Water Utility Details
SUN PRAIRIE VILLAGE COUNTY
Population Served
1,800
Water Source
Groundwater
System ID
MT0000521
GREAT FALLS CITY OF
Population Served
60,000
Water Source
Surface Water
System ID
MT0000525
Frequently Asked Questions About Great Falls Water
Is Great Falls tap water safe to drink?
Great Falls, Montana tap water receives a grade of D (36/100), which is considered poor. 0 contaminant(s) exceed EPA maximum contaminant levels and 98 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.
What contaminants are in Great Falls's water?
Of the 76 contaminants tested in Great Falls's water supply, the most notable include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Great Falls have any water quality violations?
Yes, Great Falls has 98 EPA violation(s) on record, with the most recent in 2023. Violation types include Other, MR, MCL. 6 of these are health-based violations, which are the most serious category.
Do I need a water filter in Great Falls?
Great Falls water meets EPA standards, so a filter is not strictly necessary. However, some residents prefer the added security of a water filter. EPA health goals (MCLGs) are stricter than legal limits and are set at levels with zero expected health risk. 1 contaminant(s) exceed these stricter goals.
Where does Great Falls's tap water come from?
Great Falls's drinking water is sourced from groundwater and supplied by SUN PRAIRIE VILLAGE COUNTY and 1 other water system(s). The system serves approximately 61,800 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.
How often is Great Falls's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Great Falls's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Great Falls's water compare to other cities in Montana?
Great Falls's water quality score of 36/100 earns a grade of D, which is considered poor. This is a concerning score that suggests significant water quality issues. Visit our Montana state page to see how all cities in the state compare.
What should I do if I'm concerned about Great Falls's water quality?
If you have concerns about Great Falls's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (SUN PRAIRIE VILLAGE COUNTY) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.