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
26–50 of 145City of Glendive
MT0000229 · 4,873 served
City of Columbia Falls
MT0000181 · 4,450 served
North Star Zoot Water
MT0004284 · 4,323 served
City of Dillon
MT0000201 · 4,300 served
River Rock County Water and Sewer Dist
MT0004082 · 4,200 served
Big Sky County Water and Sewer Dist 363
MT0002385 · 4,132 served
City of Shelby
MT0000328 · 3,970 served
City of Hardin
MT0000235 · 3,500 served
Lolo Water and Sewer Dist
MT0000278 · 3,315 served
City of Glasgow
MT0000415 · 3,253 served
City of Cut Bank
MT0000193 · 3,105 served
Dry Prairie Rural Water Authority
MT0004348 · 3,005 served
City of Deer Lodge
MT0000197 · 2,900 served
Conrad Water Dept
MT0000186 · 2,500 served
City of Ronan
MT0000318 · 2,483 served
Big Mountain Water Company
MT0000060 · 2,435 served
City of Colstrip
MT0000180 · 2,350 served
Rae Water and Sewer Dist 313
MT0000628 · 2,325 served
City of Forsyth
MT0000215 · 2,260 served
Pablo Lake County Water and Sewer Dist
MT0001917 · 2,175 served
City of East Helena
MT0000196 · 2,114 served
City of Troy
MT0000348 · 2,100 served
Montana State Prison
MT0000198 · 2,100 served
Town of Stevensville
MT0000335 · 2,090 served
City of Townsend
MT0000344 · 2,000 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 Glendive
Violation history, PFAS records, and official source links
City of Columbia Falls
Violation history, PFAS records, and official source links
North Star Zoot Water
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