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.
| Alert | Severity | Areas |
|---|---|---|
| High Wind Warning | Severe | Southwest Phillips |
| High Wind Watch | Severe | Central and Southeast Phillips; Central and Southern Vall… |
| High Wind Warning | Severe | Eastern Toole and Liberty; Hill County; Northern Blaine C… |
| High Wind Warning | Severe | East Glacier Park Region; Northern High Plains; Eastern G… |
| High Wind Warning | Severe | Judith Gap; Northern Sweet Grass; Melville Foothills; Sou… |
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
Areas with Most Violations
| ZIP Code | City | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|---|
| 59019 | Columbus | — | 117 | 0 | COLUMBUS TOWN OF |
| 59035 | Fort Smith | — | 83 | 19 | WORDEN BALLANTINE YELLOWSTONE |
| 59101 | Billings | — | 76 | 13 | BILLINGS CITY OF |
| 59003 | Ashland | — | 67 | 31 | ST LABRE INDIAN SCHOOL |
| 59038 | Hysham | — | 42 | 19 | HYSHAM TOWN OF |
| 59034 | Hardin | — | 26 | 0 | HARDIN CITY OF |
| 59029 | Fromberg | — | 23 | 4 | FROMBERG TOWN OF |
| 59701 | Butte | — | 20 | 0 | BUTTE SILVERBOW WATER DEPT |
| 59036 | Harlowton | — | 17 | 0 | CMRWA MUSSELSHELL JUDITH RURAL WATER SYS |
| 59401 | Great Falls | — | 14 | 0 | GREAT FALLS CITY OF |
Areas with No Violations
| ZIP Code | City | Safety Score | System | Population |
|---|---|---|---|---|
| 59008 | Belfry | — | BELFRY CARBON CO WATER AND SEWER DIST | 205 |
| 59011 | Big Timber | — | BIG TIMBER CITY OF | 1,650 |
| 59030 | Gardiner | — | GARDINER PARK CO WATER DIST | 700 |
| 59033 | Greycliff | — | COTTONWOOD ESTATES | 50 |
| 59047 | Livingston | — | LIVINGSTON CITY OF | 7,500 |
| 59801 | Missoula | — | MISSOULA WATER | 68,200 |
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
- 59001 (Absarokee) — 3 violations
- 59003 (Ashland) — 67 violations ⚠
- 59008 (Belfry)
- 59011 (Big Timber)
- 59101 (Billings) — 76 violations ⚠
- 59715 (Bozeman) — 2 violations
- 59014 (Bridger) — 3 violations
- 59015 (Broadview) — 3 violations
- 59701 (Butte) — 20 violations
- 59018 (Clyde Park) — 6 violations
- 59019 (Columbus) — 117 violations
- 59020 (Cooke City) — 12 violations
- 59027 (Emigrant) — 5 violations
- 59035 (Fort Smith) — 83 violations ⚠
- 59029 (Fromberg) — 23 violations ⚠
- 59030 (Gardiner)
- 59032 (Grass Range) — 9 violations
- 59401 (Great Falls) — 14 violations
- 59033 (Greycliff)
- 59034 (Hardin) — 26 violations
- 59036 (Harlowton) — 17 violations
- 59601 (Helena) — 12 violations ⚠
- 59037 (Huntley) — 2 violations
- 59038 (Hysham) — 42 violations ⚠
- 59041 (Joliet) — 12 violations
- 59901 (Kalispell) — 2 violations
- 59044 (Laurel) — 9 violations ⚠
- 59047 (Livingston)
- 59050 (Lodge Grass) — 5 violations
- 59053 (Martinsdale) — 2 violations
- 59054 (Melstone) — 4 violations
- 59801 (Missoula)
- 59072 (Roundup) — 3 violations
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Weather alerts: National Weather Service (NWS)
- Regulations: State plumbing boards, ICC, IAPMO
- Rebates: Rewiring America
Updated daily.