State Hub
Montana Water Quality
145
Utilities in database
0.7M
Residents served
0
With open violations
36
PFAS monitored
Quick Answer
Montana public drinking water is served by 145 EPA-tracked water systems, providing service to approximately 0.7 million residents through public utilities. No open health-based violations are currently recorded across tracked systems in the EPA federal database. 36 systems have official PFAS monitoring records from the EPA UCMR 5 program (2023–2025). About 48% of MT residents use private wells, which fall outside federal utility compliance monitoring.
No open health-based violations are currently recorded in the EPA SDWIS database for Montana's tracked water systems. Always verify with your utility's Consumer Confidence Report for annual test results.
Drinking Water in Montana
Montana has 145 community water systems serving approximately 0.7 million residents. Primary water sources include groundwater. The most commonly reported contaminants include disinfection byproducts, nitrates. 48% of Montana residents rely on private wells. MDEQ holds primary enforcement authority under the Safe Drinking Water Act.
Safest Large Utilities
Montana systems with no open health violations serving 10,000+ residents.
Utilities in Montana
1–25 of 145City of Billings
MT0000153 · 114,000 served
Missoula Water
MT0000294 · 68,200 served
City of Great Falls
MT0000525 · 60,000 served
City of Bozeman
MT0000161 · 56,000 served
Butte Silverbow Water Dept
MT0000170 · 33,000 served
Helena Water System
MT0000241 · 32,091 served
Kalispell Public Works
MT0000259 · 25,000 served
Billings Heights Co Water Dist of
MT0000155 · 12,000 served
City of Belgrade
MT0000136 · 10,460 served
City of Whitefish
MT0000357 · 10,418 served
City of Havre
MT0000524 · 9,921 served
Town of West Yellowstone
MT0003136 · 9,899 served
City of Miles City
MT0000291 · 9,565 served
Malmstrom Air Force Base
MT0000515 · 8,850 served
Flathead County Water and Sewer
MT0001744 · 7,775 served
City of Livingston
MT0000573 · 7,500 served
Anaconda Water Department
MT0000016 · 6,750 served
Laurel Municipal Water System
MT0000270 · 6,339 served
Bigfork County Water and Sewer
MT0000262 · 6,100 served
City of Lewistown
MT0000271 · 5,923 served
Lockwood Water and Sewer District
MT0000156 · 5,900 served
City of Hamilton
MT0000234 · 5,585 served
City of Polson
MT0000308 · 5,300 served
City of Sidney
MT0000330 · 5,000 served
City of Libby
MT0000274 · 4,892 served
Key Contaminant Concerns in Montana
These contaminants appear most frequently in Montana utility records or pose elevated risk in this region based on EPA data.
Nitrates
Nitrate (NO₃⁻) is a nitrogen-containing compound that forms naturally through the decomposition of organic matter. At elevated concentrations — almost always caused by human activity — nitrate is converted in the digestive system to nitrite, which then reacts with hemoglobin to form methemoglobin, a form of hemoglobin that cannot carry oxygen. In the body, nitrite also reacts with amines in food to form N-nitroso compounds (nitrosamines) — known carcinogens classified by the IARC as Group 2A (probable human carcinogens). The United States applies over 23 million tons of nitrogen fertilizer annually, making agricultural runoff the dominant source of nitrate contamination in U.S. groundwater.
EPA limit: 10 mg/L
DBPs
When utilities add chlorine to water to kill pathogens, it reacts with dissolved organic matter — leaves, algae, soil — to produce disinfection byproducts (DBPs). Over 600 DBPs have been identified. The EPA regulates two groups: total trihalomethanes (TTHMs, including chloroform) and haloacetic acids (HAA5). DBP levels tend to be highest in surface water systems and in warm months when organic matter is elevated.
EPA limit: 80 µg/L (TTHMs) / 60 µg/L (HAA5)
City Water Reports in Montana
Tap water quality pages for Montana cities — violations, PFAS records, utility profiles, and official source links.
Independent Water Testing
Find a certified lab in Montana
Utility compliance records show what water systems report to the EPA. An independent test from a certified laboratory confirms what's actually in your tap water. Montana labs can test for PFAS, lead, nitrates, bacteria, and dozens of other contaminants.
Explore Water Quality in Montana
City of Billings
Violation history, PFAS records, and official source links
Missoula Water
Violation history, PFAS records, and official source links
City of Great Falls
Violation history, PFAS records, and official source links
PFAS monitoring records — Montana
36 water systems in Montana with EPA UCMR 5 records
Lead in Montana drinking water
State-specific lead data, violation utilities, and testing guidance
PFAS in Montana drinking water
State-specific PFAS data, MCL context, and treatment options
Certified water testing labs in Montana
Labs certified for PFAS (EPA 533/537.1), lead, and bacteria testing
Water treatment options
Reverse osmosis, activated carbon, and filtration guides with cost ranges
Data sources and methodology
How WaterUtilityReport.com sources and validates official EPA data
Common Questions About Montana Drinking Water
Does Montana drinking water have PFAS?
36 Montana water systems have EPA UCMR 5 PFAS monitoring records (2023–2025)
Which Montana water utilities have open violations?
Browse Montana utility compliance records and violation history
How do I test my water in Montana?
State-certified labs for PFAS (EPA 533/537.1), lead, nitrate, and bacteria testing
What treatment removes PFAS from MT tap water?
Reverse osmosis removes PFAS, lead, arsenic, and nitrates — cost, maintenance, and NSF certification explained
What do Montana PFAS records tell me about my water?
EPA limits, health context, and what UCMR 5 detection above MRL means for your water
How is Montana water quality data sourced here?
EPA SDWIS violations, UCMR 5 PFAS records, and CCR data — sources, accuracy notes, and limitations
Montana Water FAQs
Data sources: Utility compliance and violation data from EPA SDWIS (Safe Drinking Water Information System). PFAS monitoring records from EPA UCMR 5 (Unregulated Contaminant Monitoring Rule 5, 2023–2025). Contaminant data from EPA and ATSDR public references. This page summarizes public records — it is not a compliance determination. Methodology →
Last updated: 2026-04-23