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Montana Water Quality
2,263 public water systems serving 1,112,267 people.
Water Systems
2,263
Total Violations
297,270
Violation Rate
94.7%
PFAS Detection
62.2%
28 of 45 tested
Largest Water Systems
BILLINGS CITY OF
BILLINGS, MT · 114,000 served
MISSOULA WATER
MISSOULA, MT · 68,200 served
GREAT FALLS CITY OF
GREAT FALLS, MT · 60,000 served
BOZEMAN CITY OF
BOZEMAN, MT · 56,000 served
BUTTE SILVERBOW WATER DEPT
BUTTE, MT · 33,000 served
HELENA WATER SYSTEM
HELENA, MT · 32,091 served
KALISPELL PUBLIC WORKS
KALISPELL, MT · 25,000 served
MONTANA STATE UNIVERSITY BOZEMAN
BOZEMAN, MT · 19,200 served
UNIVERSITY OF MONTANA
MISSOULA, MT · 15,000 served
CO WATER DIST OF BILLINGS HEIGHTS
BILLINGS, MT · 12,000 served
BELGRADE CITY OF
BELGRADE, MT · 10,460 served
WHITEFISH CITY OF
WHITEFISH, MT · 10,418 served
HAVRE CITY OF
HAVRE, MT · 9,921 served
WEST YELLOWSTONE TOWN OF
WEST YELLOWSTONE, MT · 9,899 served
MILES CITY CITY OF
MILES CITY, MT · 9,565 served
MALMSTROM AIR FORCE BASE
MALMSTROM AIR FORCE BASE, MT · 8,850 served
FLATHEAD COUNTY WATER AND SEWER
KALISPELL, MT · 7,775 served
LIVINGSTON CITY OF
LIVINGSTON, MT · 7,500 served
ANACONDA WATER DEPARTMENT
ANACONDA, MT · 6,750 served
LAUREL MUNICIPAL WATER SYSTEM
LAUREL, MT · 6,339 served
Most Violations
#1 MALTA CITY OF MALTA
3,072 #2 HELENA RV AND MOBILE HOME PARK HAILEY
2,806 #3 WESTVIEW MOBILE HOME PARK MISSOULA
2,111 #4 SPRINGHILL PARK SUBDIVISION BOZEMAN
1,959 #5 BRADY COUNTY WATER SEWER DISTRICT BRADY
1,954 #6 CLYDE PARK WATER DEPT CLYDE PARK
1,877 #7 ST CHARLES SCHOOL ASHLAND
1,793 #8 PLEASANT PARK COMMUNITY INC GREAT FALLS
1,791 #9 FOREST PARK WATER RSID 24 GLENDIVE
1,742 #10 RIVERSHORE COMMUNITY LLC PORT ORCHARD
1,698 #11 WHITE SULPHUR SPRINGS CITY OF WHITE SULPHUR SPRINGS
1,611 #12 BITTERROOT GATEWAY MB PK LOLO LOLO
1,600 #13 PINE CREST TR PK CAMPBELL
1,574 #14 BEARCREEK MUNICIPAL WATER SYS RED LODGE
1,555 #15 ST LABRE INDIAN SCHOOL ASHLAND
1,488 Counties in Montana
Yellowstone
116 systems · 168,956 served
· 16,006 violations
Gallatin
207 systems · 147,444 served
· 30,683 violations
Missoula
243 systems · 138,758 served
· 31,553 violations
Flathead
324 systems · 105,538 served
· 20,270 violations
Cascade
98 systems · 96,521 served
· 15,613 violations
Lewis and Clark
162 systems · 67,948 served
· 24,270 violations
Silver Bow
23 systems · 42,630 served
· 2,525 violations
Ravalli
129 systems · 30,657 served
· 9,816 violations
Lake
91 systems · 19,815 served
· 7,834 violations
Lincoln
91 systems · 19,119 served
· 7,279 violations
Mineral
37 systems · 16,697 served
· 1,421 violations
Park
58 systems · 15,803 served
· 12,317 violations
Hill
16 systems · 14,962 served
· 2,905 violations
Madison
45 systems · 14,392 served
· 4,771 violations
Fergus
20 systems · 11,162 served
· 4,498 violations
Glacier
27 systems · 10,757 served
· 3,989 violations
Custer
11 systems · 10,579 served
· 431 violations
Dawson
32 systems · 10,547 served
· 6,707 violations
Big Horn
23 systems · 10,335 served
· 6,556 violations
Jefferson
42 systems · 10,086 served
· 6,871 violations
Deer Lodge
15 systems · 9,563 served
· 2,034 violations
Beaverhead
48 systems · 9,494 served
· 6,629 violations
Broadwater
20 systems · 9,301 served
· 3,084 violations
Sanders
44 systems · 9,212 served
· 3,111 violations
Carbon
36 systems · 9,108 served
· 5,566 violations
Stillwater
31 systems · 8,417 served
· 5,741 violations
Granite
21 systems · 7,984 served
· 2,193 violations
Rosebud
15 systems · 7,415 served
· 3,651 violations
Sweet Grass
15 systems · 7,279 served
· 1,071 violations
Richland
16 systems · 7,074 served
· 4,453 violations
Showing top 30 of 56 counties.