STATE REPORT MT 6 ALERTS 101 HEALTH VIOLATIONS

Montana Water Quality & Safety Report

33 ZIP codes · 91 water systems · IPC plumbing code · Updated 2026-03-16

Data: EPA SDWIS, NWS, State plumbing boards, Rewiring America Last verified: 2026-03-16

33
ZIP Codes
91
Water Systems
27
ZIPs with Violations
6
Active Alerts
IPC
Plumbing Code

Overview

We track water quality, weather alerts, plumbing regulations, and energy rebates for 33 ZIP codes across Montana, covering 91 community water systems that serve approximately 420,154 people.

27 of 33 ZIP codes (82%) have recorded EPA violations. 101 health-based violations have been documented.

Active Weather Alerts

6 active alerts in Montana including 4 warnings. Severe weather can directly affect tap water quality — flooding, power outages, and infrastructure damage may lead to boil-water advisories.

AlertSeverityAreas
High Wind WarningSevereSouthwest Phillips
High Wind WatchSevereCentral and Southeast Phillips; Central and Southern Vall…
High Wind WarningSevereEastern Toole and Liberty; Hill County; Northern Blaine C…
High Wind WarningSevereEast Glacier Park Region; Northern High Plains; Eastern G…
High Wind WarningSevereJudith Gap; Northern Sweet Grass; Melville Foothills; Sou…

View all Montana alerts →

Plumbing Regulations

Montana follows the International Plumbing Code (2021 edition).

  • Plumbing code: IPC (2021)
  • Homeowner DIY: Allowed with permit
  • Water heater permit: Required
  • Annual backflow test: Required

Full Montana regulations →

Areas with Most Violations

ZIP CodeCitySafety ScoreViolationsHealth-BasedSystem
59019Columbus—1170COLUMBUS TOWN OF
59035Fort Smith—8319WORDEN BALLANTINE YELLOWSTONE
59101Billings—7613BILLINGS CITY OF
59003Ashland—6731ST LABRE INDIAN SCHOOL
59038Hysham—4219HYSHAM TOWN OF
59034Hardin—260HARDIN CITY OF
59029Fromberg—234FROMBERG TOWN OF
59701Butte—200BUTTE SILVERBOW WATER DEPT
59036Harlowton—170CMRWA MUSSELSHELL JUDITH RURAL WATER SYS
59401Great Falls—140GREAT FALLS CITY OF

Areas with No Violations

ZIP CodeCitySafety ScoreSystemPopulation
59008Belfry—BELFRY CARBON CO WATER AND SEWER DIST205
59011Big Timber—BIG TIMBER CITY OF1,650
59030Gardiner—GARDINER PARK CO WATER DIST700
59033Greycliff—COTTONWOOD ESTATES50
59047Livingston—LIVINGSTON CITY OF7,500
59801Missoula—MISSOULA WATER68,200

Lead & Copper

  • 0 ZIP codes exceed the EPA lead action level

Radon Risk

  • High risk (Zone 1): 0 ZIP codes (0%)
  • Moderate risk (Zone 2): 0 ZIP codes
  • Low risk (Zone 3): 0 ZIP codes

All 33 ZIP Codes in Montana

Data Sources

Updated daily.

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