PFAS contamination data for 4,721 water systems in Montana, serving 1,278,458 people.
Montana follows federal EPA MCLs (PFOA/PFOS: 4 ppt).
MT follows federal EPA MCLs. PFAS investigation at Malmstrom AFB and other sites.
Montana follows federal EPA MCLs. Contamination investigation at Malmstrom AFB and fire training areas.
Free eligibility check — plus weekly MCL, deadline, and funding alerts for Montana.
| System | City | Population | PFOA (ppt) | PFOS (ppt) | Status |
|---|---|---|---|---|---|
| BILLINGS CITY OF MT0000153 | BILLINGS | 114,000 | — | — | Compliant |
| CAMP MUSTANG MT0003181 | CORWIN SPRINGS | 75,816 | — | — | Compliant |
| MISSOULA WATER MT0000294 | MISSOULA | 68,200 | — | — | Compliant |
| GREAT FALLS CITY OF MT0000525 | GREAT FALLS | 60,000 | — | — | Compliant |
| BOZEMAN CITY OF MT0000161 | BOZEMAN | 56,000 | — | — | Compliant |
| BUTTE SILVERBOW WATER DEPT MT0000170 | BUTTE | 33,000 | — | — | Compliant |
| HELENA WATER SYSTEM MT0000241 | HELENA | 32,091 | — | — | Compliant |
| KALISPELL PUBLIC WORKS MT0000259 | KALISPELL | 25,000 | — | 6.6 | Exceeds |
| MONTANA STATE UNIVERSITY BOZEMAN MT0004790 | BOZEMAN | 19,200 | — | — | Compliant |
| UNIVERSITY OF MONTANA MT0004204 | MISSOULA | 15,000 | — | — | Compliant |
| CO WATER DIST OF BILLINGS HEIGHTS MT0000155 | BILLINGS | 12,000 | — | — | Compliant |
| BELGRADE CITY OF MT0000136 | BELGRADE | 10,460 | — | — | Compliant |
| WHITEFISH CITY OF MT0000357 | WHITEFISH | 10,418 | — | — | Compliant |
| HAVRE CITY OF MT0000524 | HAVRE | 9,921 | — | — | Compliant |
| WEST YELLOWSTONE TOWN OF MT0003136 | WEST YELLOWSTONE | 9,899 | — | — | Compliant |
| MILES CITY CITY OF MT0000291 | MILES CITY | 9,565 | — | — | Compliant |
| MALMSTROM AIR FORCE BASE MT0000515 | MALMSTROM AIR FORCE BASE | 8,850 | — | — | Compliant |
| FLATHEAD COUNTY WATER AND SEWER MT0001744 | KALISPELL | 7,775 | — | — | Compliant |
| LIVINGSTON CITY OF MT0000573 | LIVINGSTON | 7,500 | — | — | Compliant |
| ANACONDA WATER DEPARTMENT MT0000016 | ANACONDA | 6,750 | — | — | Compliant |
| LAUREL MUNICIPAL WATER SYSTEM MT0000270 | LAUREL | 6,339 | — | — | Compliant |
| BIGFORK COUNTY WATER AND SEWER MT0000262 | BIGFORK | 6,100 | — | — | Compliant |
| LEWISTOWN CITY OF MT0000271 | LEWISTOWN | 5,923 | — | — | Compliant |
| LOCKWOOD WATER AND SEWER DISTRICT MT0000156 | BILLINGS | 5,900 | — | — | Compliant |
| ROCKY MOUNTAIN COLLEGE MT0004796 | BILLINGS | 5,700 | — | — | Compliant |
| HAMILTON CITY OF MT0000234 | HAMILTON | 5,585 | — | — | Compliant |
| POLSON CITY OF MT0000308 | POLSON | 5,300 | — | — | Compliant |
| SIDNEY CITY OF MT0000330 | SIDNEY | 5,000 | — | — | Compliant |
| LIBBY CITY OF MT0000274 | LIBBY | 4,892 | — | — | Compliant |
| GLENDIVE CITY OF MT0000229 | GLENDIVE | 4,873 | — | — | Compliant |
| BROWNING TOWN OF MT0000169 | BROWNING | 4,773 | — | — | Compliant |
| TOWN OF BROWNING 083090091 | BROWNING | 4,671 | — | — | Compliant |
| COLUMBIA FALLS CITY OF MT0000181 | COLUMBIA FALLS | 4,450 | — | — | Compliant |
| NORTH STAR ZOOT WATER MT0004284 | BOZEMAN | 4,323 | — | — | Compliant |
| DILLON CITY OF MT0000201 | DILLON | 4,300 | — | — | Compliant |
| RIVER ROCK COUNTY WATER AND SEWER DIST MT0004082 | BELGRADE | 4,200 | — | — | Compliant |
| BIG SKY COUNTY WATER AND SEWER DIST 363 MT0002385 | BIG SKY | 4,132 | — | — | Compliant |
| VALLEY WATER COMPANY MT0001577 | HAMILTON | 4,000 | — | — | Compliant |
| SHELBY CITY OF MT0000328 | SHELBY | 3,970 | — | — | Compliant |
| GLASGOW WATER CONDITIONING MT0003401 | GLASGOW | 3,500 | — | — | Compliant |
| HARDIN CITY OF MT0000235 | HARDIN | 3,500 | — | — | Compliant |
| LOLO WATER AND SEWER DIST MT0000278 | LOLO | 3,315 | — | — | Compliant |
| GLASGOW CITY OF MT0000415 | GLASGOW | 3,253 | — | — | Compliant |
| BIG SKY DRINKING WATER INC MT0003371 | CORVALLIS | 3,025 | — | — | Compliant |
| POPLAR, CITY OF 083090051 | POPLAR | 3,025 | — | — | Compliant |
| DRY PRAIRIE RURAL WATER AUTHORITY MT0004348 | CULBERTSON | 3,005 | — | — | Compliant |
| WOLF POINT CITY OF 083090058 | WOLF POINT | 3,000 | — | — | Compliant |
| MONTANA STATE UNIVERSITY BILLINGS MT0004788 | BILLINGS | 2,999 | — | — | Compliant |
| POPLAR CITY OF MT0000310 | POPLAR | 2,926 | — | — | Compliant |
| DEER LODGE CITY OF MT0000197 | DEER LODGE | 2,900 | — | — | Compliant |
| MEADOW VILLAGE BIG SKY MT0002384 | BIG SKY | 2,756 | — | — | Compliant |
| LAME DEER WATER SYSTEM 083090064 | LAME DEER | 2,605 | — | — | Compliant |
| CONSOLIDATED CHEYENNE US MT0000008 | LAME DEER | 2,500 | — | — | Compliant |
| CONRAD WATER DEPT MT0000186 | CONRAD | 2,500 | — | — | Compliant |
| RONAN CITY OF MT0000318 | RONAN | 2,483 | — | — | Compliant |
| BIG MOUNTAIN WATER COMPANY MT0000060 | WHITEFISH | 2,435 | — | — | Compliant |
| COLSTRIP CITY OF MT0000180 | COLSTRIP | 2,350 | — | — | Compliant |
| FORSYTH CITY OF MT0000215 | FORSYTH | 2,260 | — | — | Compliant |
| ROCKER WATER AND SEWER DISTRICT MT0003478 | ROCKER | 2,250 | — | — | Compliant |
| WELBORN AQUA HAUL MT0005114 | BELGRADE | 2,246 | — | — | Compliant |
| RAE WATER AND SEWER DIST 313 MT0000628 | BOZEMAN | 2,220 | — | — | Compliant |
| PABLO LAKE COUNTY WATER AND SEWER DIST MT0001917 | PABLO | 2,175 | — | — | Compliant |
| EAST HELENA CITY OF MT0000196 | EAST HELENA | 2,114 | — | — | Compliant |
| FORT BELKNAP AGENCY WATER SYSTEM 083090041 | HARLEM | 2,100 | — | — | Compliant |
| TROY CITY OF MT0000348 | TROY | 2,100 | — | — | Compliant |
| MONTANA STATE PRISON MT0000198 | DEER LODGE | 2,100 | — | — | Compliant |
| STEVENSVILLE TOWN OF MT0000335 | STEVENSVILLE | 2,090 | — | — | Compliant |
| TOWNSEND CITY OF MT0000344 | TOWNSEND | 2,000 | — | — | Compliant |
| EASTGATE VILLAGE SEWER AND WATER MT0001784 | EAST HELENA | 2,000 | — | — | Compliant |
| RED LODGE WATER DEPT MT0000314 | RED LODGE | 2,000 | — | — | Compliant |
| ROCKY BOY'S RURAL WATER 083090075 | BOX ELDER | 2,000 | — | — | Compliant |
| EUREKA TOWN OF MT0000210 | EUREKA | 1,995 | — | — | Compliant |
| FAIRMONT HOT SPRINGS RESORT MT0000589 | ANACONDA | 1,965 | — | — | Compliant |
| THREE FORKS CITY OF MT0000343 | THREE FORKS | 1,900 | — | — | Compliant |
| ROUNDUP WATER DEPARTMENT MT0000321 | ROUNDUP | 1,900 | — | — | Compliant |
| COLUMBUS TOWN OF MT0000185 | COLUMBUS | 1,900 | — | — | Compliant |
| BAKER CITY OF MT0000021 | BAKER | 1,858 | — | — | Compliant |
| MALTA CITY OF MT0000284 | MALTA | 1,800 | — | — | Compliant |
| MANHATTAN TOWN OF MT0000285 | MANHATTAN | 1,800 | — | — | Compliant |
| SUN PRAIRIE VILLAGE COUNTY MT0000521 | GREAT FALLS | 1,800 | — | — | Compliant |
| ASSINIBOINE & SIOUX RURAL WATER SYSTEM 083090050 | POPLAR | 1,726 | — | — | Compliant |
| HILL COUNTY WATER DISTRICTS MT0000249 | HINGHAM | 1,720 | — | — | Compliant |
| PLENTYWOOD WATER DEPARTMENT MT0000306 | PLENTYWOOD | 1,700 | — | — | Compliant |
| PLAINS TOWN OF MT0000305 | PLAINS | 1,700 | — | — | Compliant |
| CHOTEAU CITY OF MT0000175 | CHOTEAU | 1,691 | — | — | Compliant |
| BIG TIMBER CITY OF MT0000463 | BIG TIMBER | 1,650 | — | — | Compliant |
| SEELEY LAKE WATER DISTRICT MT0000327 | SEELEY LAKE | 1,575 | — | — | Compliant |
| TWO MEDICINE WATER - EAST GLACIER 083090090 | BROWNING | 1,504 | — | — | Compliant |
| VIRGINIA CITY WATER DEPT MT0000353 | VIRGINIA CITY | 1,500 | — | — | Compliant |
| YELLOWSTONE ICE AND WATER MT0003429 | BILLINGS | 1,500 | — | — | Compliant |
| FORT BENTON CITY OF MT0000216 | FORT BENTON | 1,500 | — | — | Compliant |
| WHITEHALL TOWN OF MT0000359 | WHITEHALL | 1,500 | — | — | Compliant |
| ROCKY BOY AGENCY WATER SYSTEM 083090079 | BOX ELDER | 1,442 | — | — | Compliant |
| ENNIS TOWN OF MT0000208 | ENNIS | 1,400 | — | — | Compliant |
| BOULDER CITY OF MT0000158 | BOULDER | 1,400 | — | — | Compliant |
| WORDEN COMMUNITY WUA MT0000365 | WORDEN | 1,400 | — | — | Compliant |
| PHILIPSBURG TOWN OF MT0000304 | PHILIPSBURG | 1,360 | — | — | Compliant |
| EL MAR ESTATES MSLA CO WATER MT0000517 | MISSOULA | 1,350 | — | — | Compliant |
| CROW AGENCY WATER SYSTEM 083090011 | CROW AGENCY | 1,300 | — | — | Compliant |
| CHINOOK CITY OF MT0000174 | CHINOOK | 1,300 | — | — | Compliant |
| VA MEDICAL CENTER HELENA MT0000246 | FORT HARRISON | 1,275 | — | — | Compliant |
| BLACK EAGLE CASCADE COUNTY WATER SEWER MT0000157 | BLACK EAGLE | 1,233 | — | — | Compliant |
| LAKESIDE WATER SYSTEM MT0000266 | LAKESIDE | 1,225 | — | — | Compliant |
| FOREST PARK WATER RSID 24 MT0000233 | GLENDIVE | 1,200 | — | — | Compliant |
| HELENA LEISURE LLC MT0000590 | HELENA | 1,200 | — | — | Compliant |
| CROW AGENCY WATER PLANT MT0000190 | CROW AGENCY | 1,200 | — | — | Compliant |
| HUNGRY HORSE CO WATER AND SEWER DISTRICT MT0000253 | HUNGRY HORSE | 1,135 | — | — | Compliant |
| SUPERIOR TOWN OF MT0000339 | SUPERIOR | 1,100 | — | — | Compliant |
| ABSAROKEE WATER AND SEWER DIST MT0000003 | ABSAROKEE | 1,100 | — | — | Compliant |
| HARLOWTON CITY OF MT0000240 | HARLOWTON | 1,050 | — | — | Compliant |
| ST MARY HEADQUARTERS AND CG MT0002729 | WEST GLACIER | 1,030 | — | — | Compliant |
| SCOBEY CITY OF MT0000326 | SCOBEY | 1,026 | — | — | Compliant |
| WHITE SULPHUR SPRINGS CITY OF MT0000360 | WHITE SULPHUR SPRINGS | 1,000 | — | — | Compliant |
| PRAIRIE WATER COMPANY MT0003539 | GREAT FALLS | 1,000 | — | — | Compliant |
| FAIRVIEW TOWN OF MT0000213 | FAIRVIEW | 1,000 | — | — | Compliant |
| MEADOW LAKE CO WATER AND SEWER DISTRICT MT0000914 | COLUMBIA FALLS | 950 | — | — | Compliant |
| WESTVIEW MOBILE HOME PARK MT0000437 | MISSOULA | 947 | — | — | Compliant |
| CULLIGAN WATER CONDITIONING GREAT FALLS MT0002630 | GREAT FALLS | 900 | — | — | Compliant |
| EAST GLACIER CO WATER AND SEWER DIST MT0002887 | EAST GLACIER | 900 | — | — | Compliant |
| PIONEER WATER SERVICE MT0004226 | BILLINGS | 900 | — | — | Compliant |
| CHESTER TOWN OF MT0000173 | CHESTER | 870 | — | — | Compliant |
| DARBY TOWN OF MT0000195 | DARBY | 850 | — | — | Compliant |
| HAYS/WHITE COW CANYON WS 083090044 | HARLEM | 840 | — | — | Compliant |
| VALLEY GROVE SUBDIVISION MT0003780 | BELGRADE | 825 | — | — | Compliant |
| HARLEM CITY OF MT0000239 | HARLEM | 820 | — | — | Compliant |
| PHANTOM HILLS WATER SYSTEM MT0004379 | MISSOULA | 810 | — | — | Compliant |
| WORDEN BALLANTINE YELLOWSTONE MT0000022 | FORT SMITH | 800 | — | — | Compliant |
| PINESDALE TOWN OF MT0002926 | PINESDALE | 800 | — | — | Compliant |
| JEFFERSON HILLS WUA MT0002978 | HELENA | 780 | — | — | Compliant |
| SOMERS CO WATER AND SEWER DIST MT0000332 | SOMERS | 765 | — | — | Compliant |
| FISHER WATER SERVICE MT0001848 | BILLINGS | 750 | — | — | Compliant |
| TIBER COUNTY WATER DISTRICT MT0000400 | BRADY | 750 | — | — | Compliant |
| BRIDGER TOWN OF MT0000165 | BRIDGER | 750 | — | — | Compliant |
| FORT BELKNAP INDIAN AGENCY MT0000238 | HARLEM | 750 | — | — | Compliant |
| LANDMARK SUBDIVISION MT0004262 | BOZEMAN | 750 | — | — | Compliant |
| MONTANA STATE HOSPITAL COMPLEX MT0004805 | WARM SPRINGS | 721 | — | — | Compliant |
| FAIRFIELD TOWN OF MT0000212 | FAIRFIELD | 718 | — | — | Compliant |
| NORTH STAR PUD MT0004264 | HELENA | 715 | — | — | Compliant |
| CULBERTSON TOWN OF MT0000192 | CULBERTSON | 714 | — | — | Compliant |
| TRAVOIS VILLAGE MOBILE PARK MT0003909 | MISSOULA | 702 | — | — | Compliant |
| ST IGNATIUS TOWN OF MT0001740 | ST IGNATIUS | 700 | — | — | Compliant |
| GARDINER PARK CO WATER DIST MT0000224 | GARDINER | 700 | — | — | Compliant |
| WOODS BAY WATER AND SEWER DISTRICT MT0004698 | BIGFORK | 685 | — | — | Compliant |
| ELK GROVE WATER MT0004248 | BOZEMAN | 672 | — | — | Compliant |
| GENESIS BUSINESS PARK MT0004178 | GALLATIN GATEWAY | 670 | — | — | Compliant |
| FORT PECK RURAL COUNTY WATER DISTRICT MT0004177 | FT. PECK | 663 | — | — | Compliant |
| ST LABRE INDIAN SCHOOL MT0000018 | ASHLAND | 650 | — | — | Compliant |
| CASCADE TOWN OF MT0000171 | CASCADE | 650 | — | — | Compliant |
| BEDROCKBABB WATER SYSTEM 083090004 | BROWNING | 645 | — | — | Compliant |
| CIRCLE TOWN OF MT0000176 | CIRCLE | 644 | — | — | Compliant |
| SHERIDAN TOWN OF MT0000329 | SHERIDAN | 632 | — | — | Compliant |
| GREENFIELD MOBILE HOME PARK MT0000373 | MISSOULA | 620 | — | — | Compliant |
| BIG SANDY TOWN OF MT0000150 | BIG SANDY | 608 | — | — | Compliant |
| HOT SPRINGS MUNICIPAL WATER MT0000251 | HOT SPRINGS | 600 | — | — | Compliant |
| BELT TOWN OF MT0000138 | BELT | 600 | — | — | Compliant |
| PTARMIGAN VILLAGE INC MT0000133 | WHITEFISH | 600 | — | — | Compliant |
| JOLIET TOWN OF MT0000256 | JOLIET | 600 | — | — | Compliant |
| MEDICINE LAKE TOWN OF MT0000289 | MEDICINE LAKE | 600 | — | — | Compliant |
| CEDAR PARK WATER PLANT MT0000625 | BILLINGS | 600 | — | — | Compliant |
| CHERRY CREEK ESTATES LLC MT0004392 | BILLINGS | 600 | — | — | Compliant |
| VAUGHN CASCADE COUNTY WATER AND SEWER MT0000352 | VAUGHN | 585 | — | — | Compliant |
| WIBAUX TOWN OF MT0000361 | WIBUAX | 550 | — | — | Compliant |
| FRENCHTOWN HIGH SCHOOL MT0000856 | FRENCHTOWN | 550 | — | — | Compliant |
| BUSBY COMMUNITY WATER SYSTEM 083090063 | LAME DEER | 535 | — | — | Compliant |
| WINDSOR ESTATES MT0003807 | LINCOLN | 530 | — | — | Compliant |
| TWO BUTTES WATER USERS ASSN MT0000580 | FORT SHAW | 525 | — | — | Compliant |
| WYE AREA WATER SYSTEM MT0004107 | MISSOULA | 512 | — | — | Compliant |
| HEADQUARTERS APGAR MT0003176 | WEST GLACIER | 500 | — | — | Compliant |
| RUDYARD WATER USERS MT0003126 | HINGHAM | 500 | — | — | Compliant |
| MT STATE HOSPITAL WARM SPRINGS MT0000354 | WARM SPRINGS | 500 | — | — | Compliant |
| W YELLOWSTONE MT SPRING WATER MT0003661 | WEST YELLOWSTONE | 500 | — | — | Compliant |
| CAMP CREEK CAMPGROUND - BLM MT0003222 | LEWISTOWN | 500 | — | — | Compliant |
| COVERED WAGON MB HM PARK MT0003810 | LINCOLN | 500 | — | — | Compliant |
| HOMESTEAD ACRES COUNTY WATER AND SEWER MT0000526 | GREAT FALLS | 500 | — | — | Compliant |
| HIGHLAND PARK UTILITIES ASSN MT0000570 | GLENDIVE | 500 | — | — | Compliant |
| GORE HILL COUNTY WATER DIST MT0000232 | GREAT FALLS | 500 | — | — | Compliant |
| FROMBERG TOWN OF MT0000222 | FROMBERG | 500 | — | — | Compliant |
| ALBERTON TOWN OF MT0000015 | ALBERTON | 495 | — | — | Compliant |
| LODGE GRASS TOWN OF MT0000277 | LODGE GRASS | 480 | — | — | Compliant |
| CUSTER CO WATER AND SEWER DIST MT0003041 | MILES CITY | 480 | — | — | Compliant |
| CUT BANK NORTH WATER DISTRICT MT0000619 | CUT BANK | 478 | — | — | Compliant |
| PRYOR CREEK WATER ASSN MT0002956 | HUNTLEY | 475 | — | — | Compliant |
| FLATHEAD CO WATER DISTRICT NO 8 MT0000261 | COLUMBIA FALLS | 475 | — | — | Compliant |
| TRI COUNTY WATER DISTRICT MT0002912 | POWER | 470 | — | — | Compliant |
| SUNBURST TOWN OF MT0000338 | SUNBURST | 459 | — | — | Compliant |
| INDIAN SPRINGS RANCH SUB MT0004611 | EUREKA | 455 | — | — | Compliant |
| VALIER TOWN OF MT0000351 | VALIER | 452 | — | — | Compliant |
| FRAZER WATER SYSTEM 083090053 | WOLF POINT | 452 | — | — | Compliant |
| NORTH VALLEY COUNTY WATER AND SEWER DIST MT0003595 | GLASGOW | 450 | — | — | Compliant |
| BROADUS TOWN OF MT0000166 | BROADUS | 450 | — | — | Compliant |
| FORT SMITH WATER AND SEWER DISTRICT MT0004765 | FORT SMITH | 450 | — | — | Compliant |
| BAXTER CREEK NO 2 HOA MT0003323 | BELGRADE | 450 | — | — | Compliant |
| ANDESITE RIDGE WATER SYSTEM MT0004468 | BIG SKY | 450 | — | — | Compliant |
| FROID TOWN OF MT0000221 | FROID | 450 | — | — | Compliant |
| CORAM COUNTY WATER AND SEWER DISTRICT MT0000189 | CORAM | 450 | — | — | Compliant |
| CONSOLIDATED CHARLO LAKE CO W AND S DIST MT0000172 | CHARLO | 450 | — | — | Compliant |
| DRY PRAIRIE VALLEY COUNTY MT0004708 | CULBERTSON | 440 | — | — | Compliant |
| BUSHARD WATER COMPANY MT0005164 | BLACK EAGLE | 425 | — | — | Compliant |
| STANFORD TOWN OF MT0000334 | STANFORD | 425 | — | — | Compliant |
| TWIN BRIDGES TOWN OF MT0000349 | TWIN BRIDGES | 424 | — | — | Compliant |
| PRYOR WATER SYSTEM 083090012 | CROW AGENCY | 406 | — | — | Compliant |
| LA CASA GRANDE WATER AND SEWER DISTRICT MT0001924 | EAST HELENA | 404 | — | — | Compliant |
| HEART BUTTE WATER SYSTEM 083090005 | BROWNING | 400 | — | — | Compliant |
| ASHLAND WATER AND SEWER DIST MT0000458 | ASHLAND | 400 | — | — | Compliant |
| HIGHWOOD MOBILE HOME PARK MT0004681 | GREAT FALLS | 400 | — | — | Compliant |
| JOPLIN WATER USERS MT0003129 | HINGHAM | 400 | — | — | Compliant |
| ROUND BUTTE WATER COMPANY MT0000320 | RONAN | 400 | — | — | Compliant |
| GOLDEN ESTATES HOMEOWNERS ASSOCIATION MT0004187 | EAST HELENA | 400 | — | — | Compliant |
| EL-MAR TRAILER COURT MT0000375 | MISSOULA | 400 | — | — | Compliant |
| EAGLEMAN COMMUNITY WATER 083090074 | BOX ELDER | 400 | — | — | Compliant |
| FRAZER WATER USERS ASSN MT0000220 | FRAZER | 400 | — | — | Compliant |
| EKALAKA TOWN OF MT0000206 | EKALAKA | 400 | — | — | Compliant |
| WYLIE CREEK ESTATES SUBDIVISION MT0003961 | BOZEMAN | 400 | — | — | Compliant |
| SKYVIEW WATER AND SEWER UTILITY MT0004039 | EAST HELENA | 400 | — | — | Compliant |
| FOREST ACRES TR PK WHITEFISH MT0000064 | WHITEFISH | 390 | — | — | Compliant |
| GRANT CREEK WATER USERS ASSOCIATION INC MT0003305 | MISSOULA | 380 | — | — | Compliant |
| SUNDANCE SUBDIVISION MT0005056 | BILLINGS | 378 | — | — | Compliant |
| STONE CREEK SUBDIVISION MT0005183 | BILLINGS | 378 | — | — | Compliant |
| JETTE MEADOWS LAKE CO W AND S DIST MT0003100 | POLSON | 375 | — | — | Compliant |
| BROCKTON, TOWN OF 083090057 | WOLF POINT | 375 | — | — | Compliant |
| DRY REDWATER REGIONAL WATER AUTHORITY MT0004839 | CIRCLE | 365 | — | — | Compliant |
| JORDAN TOWN OF MT0000257 | JORDAN | 364 | — | — | Compliant |
| ST IGNATIUS (MISSION) SO.SIDE 083090031 | PABLO | 356 | — | — | Compliant |
| MT MOONLIGHT BASIN MT0004023 | BELGRADE | 355 | — | — | Compliant |
| CHERRY VIEW MT0004856 | LAKESIDE | 352 | — | — | Compliant |
| HIDDEN LAKE YELLOWSTONE COUNTY W AND S D MT0003374 | BILLINGS | 350 | — | — | Compliant |
| FIRELIGHT MEADOWS LLC MT0004236 | BOZEMAN | 350 | — | — | Compliant |
| SADDLE MOUNTAIN CORP CLANCY MT0000057 | CLANCY | 350 | — | — | Compliant |
| BAINVILLE TOWN OF MT0000020 | BAINVILLE | 350 | — | — | Compliant |
| WATER SERVICE INC TROUT CREEK MT0000347 | TROUT CREEK | 350 | — | — | Compliant |
| MONTANA DEVELOPMENT CENTER MT0000159 | BOULDER | 350 | — | — | Compliant |
| FORT SMITH W AND S DIST FORT SMITH TR PK MT0000104 | FORT SMITH | 350 | — | — | Compliant |
| 779 RADAR SQUADRON MT0000500 | OPHEIM AFS | 350 | — | — | Compliant |
| LOWER PIONEER MOUNTAIN WATER SYSTEM MT0004462 | BIG SKY | 350 | — | — | Compliant |
| SUN PRAIRIE WATER DISTRICT MT0000571 | GREAT FALLS | 350 | — | — | Compliant |
| MARTIN CITY COUNTY WATER DISTRICT MT0000286 | MARTIN CITY | 340 | — | — | Compliant |
| DUTTON TOWN OF MT0000204 | DUTTON | 338 | — | — | Compliant |
| IRON HORSE HOMEOWNERS ASSOC MT0004052 | COLUMBIA FALLS | 335 | — | — | Compliant |
| NOXON WATER DISTRICT MT0000299 | NOXON | 330 | — | — | Compliant |
| V.A. MEDICAL CENTER MILES CITY MT0001933 | MILES CITY | 325 | — | — | Compliant |
| FOREST PARK WATER USERS ASSOCIATION MT0000591 | CLANCY | 323 | — | — | Compliant |
| MIDVALE WATER AND SEWER DISTRICT MT0000211 | EUREKA | 320 | — | — | Compliant |
| EMERALD VIEW PARK MT0002996 | BILLINGS | 320 | — | — | Compliant |
| MOUNTAIN ACRES MB HM PK MT0003809 | LINCOLN | 320 | — | — | Compliant |
| SHILOH ROAD DEVELOPMENT MT0005178 | BILLINGS | 315 | — | — | Compliant |
| SOUTHSIDE PUBLIC WATER SUPPLY MT0002652 | KALISPELL | 306 | — | — | Compliant |
| BIG SKY OF MONT INC MT0000151 | BIG SKY | 300 | — | — | Compliant |
| MOBILE CITY HOME PARK NO 2 MT0003043 | BILLINGS | 300 | — | — | Compliant |
| GILDFORD WATER USERS MT0003123 | HINGHAM | 300 | — | — | Compliant |
| MOUNTAIN MEADOWS ESTATES LLP MT0001791 | BILLINGS | 300 | — | — | Compliant |
| HIGHLAND PARK WATER ASSOC MT0000230 | DAWSON | 300 | — | — | Compliant |
| SEVILLE WATER SYSTEM 083090008 | BROWNING | 300 | — | — | Compliant |
| ROBERTS WUA CARBON CO WATER AND SEWER MT0000317 | ROBERTS | 300 | — | — | Compliant |
| NASHUA TOWN OF MT0000297 | NASHUA | 300 | — | — | Compliant |
| OILMONT COUNTY WATER DISTRICT MT0000587 | SUNBURST | 300 | — | — | Compliant |
| HILDRETH SUBDIVISION NO 2 MT0002486 | DILLON | 300 | — | — | Compliant |
| KELLER SUBDIVISION NO 2 HOA MT0002485 | DILLON | 300 | — | — | Compliant |
| COOKE CITY WATER DISTRICT MT0000187 | COOKE CITY | 300 | — | — | Compliant |
| CLYDE PARK WATER DEPT MT0000178 | CLYDE PARK | 300 | — | — | Compliant |
| NORTHERN PINES COMMUNITY HOA MT0004193 | COLUMBIA FALLS | 295 | — | — | Compliant |
| JETTE LAKE LANDOWNERS ASSOCIATION MT0003102 | POLSON | 295 | — | — | Compliant |
| KEVIN TOWN OF MT0000265 | KEVIN | 290 | — | — | Compliant |
| ANACONDA CCC MT0062254 | ANACONDA | 290 | — | — | Compliant |
| RIDGEWOOD TERRACE MHP MT0004186 | LINCOLN | 280 | — | — | Compliant |
| HIGHWOOD COUNTY WATER AND SEWER DISTRICT MT0000248 | HIGHWOOD | 280 | — | — | Compliant |
| LIMA TOWN OF MT0000276 | LIMA | 279 | — | — | Compliant |
| HIDDEN VILLAGE MT0002386 | BIG SKY | 276 | — | — | Compliant |
| TRAPPER CREEK JOB CORPS MT0062207 | DARBY | 275 | — | — | Compliant |
| WINIFRED TOWN OF MT0000363 | WINIFRED | 274 | — | — | Compliant |
| GREAT FALLS RV PARK MT0000027 | GREAT FALLS | 274 | — | — | Compliant |
| ALPINE PACIFIC UTILITIES MT0004700 | SOMERS | 270 | — | — | Compliant |
| RYEGATE TOWN OF MT0000322 | RYEGATE | 270 | — | — | Compliant |
| ASHLAND COMMUNITY WATER SYSTEM 083090061 | LAME DEER | 265 | — | — | Compliant |
| HYSHAM TOWN OF MT0000428 | HYSHAM | 262 | — | — | Compliant |
| WYOLA WATER SYSTEM 083090014 | CROW AGENCY | 261 | — | — | Compliant |
| COUNTRY LAKE HOMES WHITEFISH MT0003031 | KALISPELL | 260 | — | — | Compliant |
| GERALDINE TOWN OF MT0000225 | GERALDINE | 260 | — | — | Compliant |
| KATOONAH LODGES MT0003692 | MISSOULA | 258 | — | — | Compliant |
| DENTON TOWN OF MT0000199 | DENTON | 255 | — | — | Compliant |
| KICKING HORSE JOB CENTER MT0000558 | RONAN | 250 | — | — | Compliant |
| TROUTBECK RISE LAKESIDE EST WATER SYSTEM MT0000267 | LAKESIDE | 250 | — | — | Compliant |
| SORREL SPRINGS HOA MT0000518 | FRENCHTOWN | 250 | — | — | Compliant |
| RIDGEWOOD ESTATES MT0003175 | BIGFORK | 250 | — | — | Compliant |
| BLUE SKY HEIGHTS WUA CLANCY MT0000030 | CLANCY | 250 | — | — | Compliant |
| LEXLEY ACRES MOBILE HOME PARK MT0000461 | BELGRADE | 250 | — | — | Compliant |
| WILSALL WATER DISTRICT MT0000362 | WILSALL | 250 | — | — | Compliant |
| ANACONDA CIVILIAN CONS CENTER MT0000017 | ANACONDA | 250 | — | — | Compliant |
| HEART BUTTE SCHOOL 083090009 | HEART BUTTE | 250 | — | — | Compliant |
| STARR SCHOOL WATER SYSTEM 083090007 | BROWNING | 250 | — | — | Compliant |
| HILLTOP TERRACE NO 2 COLUMBIA F MT0003399 | KALISPELL | 250 | — | — | Compliant |
| GRANITE PARK WATER ASSOCIATION MT0004563 | BILLINGS | 250 | — | — | Compliant |
| MEADOW VILLAGE WATER DISTRICT MT0000645 | SIDNEY | 250 | — | — | Compliant |
| PACHE WATER SYSTEM 083090036 | PABLO | 250 | — | — | Compliant |
| HINSDALE WATER DEPARTMENT MT0000250 | HINSDALE | 250 | — | — | Compliant |
| PRECISION WATER MT0004497 | BILLINGS | 250 | — | — | Compliant |
| PONDEROSA HOMEOWNERS ASSN INC MT0002863 | KALISPELL | 246 | — | — | Compliant |
| YELLOWSTONE BOYS AND GIRLS RANCH MT0000154 | BILLINGS | 240 | — | — | Compliant |
| FORT PECK TOWN OF MT0000218 | FORT PECK | 240 | — | — | Compliant |
| HEART BUTTE SCHOOL MT0003160 | HEART BUTTE | 240 | — | — | Compliant |
| WELLS GARDEN ESTATES MT0002927 | BILLINGS | 240 | — | — | Compliant |
| GREEN TREE MEADOWS COUNTY W &/OR S DIST MT0003194 | BIGFORK | 237 | — | — | Compliant |
| EAGLE BEND DEVELOPMENT MT0003071 | BIGFORK | 235 | — | — | Compliant |
| SPIRIT HILLS SUBDIVISION MT0004208 | BOZEMAN | 230 | — | — | Compliant |
| KOKANEE BEND HOA MT0002997 | COLUMBIA FALLS | 230 | — | — | Compliant |
| HUNTLEY YELLOWSTONE CO WATER AND SEWER MT0000254 | HUNTLEY | 230 | — | — | Compliant |
| HEBGEN LAKE ESTATES CO WATER SEWER DISTR MT0001983 | WEST YELLOWSTONE | 230 | — | — | Compliant |
| CLANCY WATER DEPT MT0000177 | CLANCY | 230 | — | — | Compliant |
| NEIHART TOWN OF MT0000298 | NEIHART | 229 | — | — | Compliant |
| GRASS LAND ESTATES MT0004448 | EAST HELENA | 228 | — | — | Compliant |
| TURTLE LAKE WATER SYSTEM 083090032 | PABLO | 225 | — | — | Compliant |
| CRYSTAL SPRINGS WATER SYSTEM MT0003986 | BILLINGS | 225 | — | — | Compliant |
| HOLMBERG VILLAGE ESTATES MT0004190 | HELENA | 225 | — | — | Compliant |
| LAST STARR HOMES (INACTIVE) 083090006 | BROWNING | 225 | — | — | Compliant |
| SAGE CREEK CO WATER DISTRICT MT0003150 | CHESTER | 225 | — | — | Compliant |
| FORT KIPP SUBDIVISION WATER SYSTEM 083090052 | WOLF POINT | 221 | — | — | Compliant |
| MNIHNAPA WATER SYSTEM 083090047 | HARLEM | 220 | — | — | Compliant |
| THE NINES SUBDIVISION MT0004989 | BILLINGS | 220 | — | — | Compliant |
| HOLLYWOOD HEIGHTS TRAILER PARK LLC MT0000454 | MISSOULA | 220 | — | — | Compliant |
| DIXON, TOWN OF 083090034 | PABLO | 216 | — | — | Compliant |
| SALISH SHORES TRADE WINDS COMM VILLAGE MT0003911 | THOMPSON FALLS | 215 | — | — | Compliant |
| CIRCLE H WATER INC MT0004446 | MISSOULA | 215 | — | — | Compliant |
| ELMO WATER SYSTEM 083090024 | PABLO | 210 | — | — | Compliant |
| WAGON WHEEL TRAILER VILLAGE MT0000379 | MISSOULA | 210 | — | — | Compliant |
| FLATHEAD COUNTY WATER DIST 101 MT0000184 | COLUMBIA FALLS | 210 | — | — | Compliant |
| GLACIER POINT HO AND WUA MT0004559 | HELENA | 210 | — | — | Compliant |
| STOCKETT WATER AND SEWER DIST MT0000579 | STOCKETT | 210 | — | — | Compliant |
| WILDERNESS PLATEAU WATER AND SEWER DIST MT0002985 | TROY | 208 | — | — | Compliant |
| EAST GATE WORK CAMP MT0003440 | GARDINER | 208 | — | — | Compliant |
| HAPPY VALLEY WATER DIST B KSPL MT0001984 | COLUMBIA FALLS | 207 | — | — | Compliant |
| GOODAN KEIL CO WATER DIST MT0002393 | MISSOULA | 207 | — | — | Compliant |
| BELFRY CARBON CO WATER AND SEWER DIST MT0000460 | BELFRY | 205 | — | — | Compliant |
| POWER TETON COUNTY WATER DIST MT0000311 | POWER | 205 | — | — | Compliant |
| BRIDGE CREEK ESTATES SUBDIVISION MT0004555 | EAST HELENA | 205 | — | — | Compliant |
| LION MOUNTAIN HOMEOWNERS ASSOC MT0000392 | COLUMBIA FALLS | 204 | — | — | Compliant |
| KREMLIN WATER USERS MT0003121 | HINGHAM | 200 | — | — | Compliant |
| GO 2 U WATER DELIVERY MT0004754 | LAUREL | 200 | — | — | Compliant |
| PARADISE WATER DISTRICT MT0000385 | PARADISE | 200 | — | — | Compliant |
| SOUTH WIND WATER AND SEWER DISTRICT MT0000025 | GREAT FALLS | 200 | — | — | Compliant |
| JETTE MEADOWS LAKE CO W&S DIST PHASE II MT0003101 | POLSON | 200 | — | — | Compliant |
| TRACY WATER USERS CORP MT0000345 | SAND COULEE | 200 | — | — | Compliant |
| BASIN COUNTY WATER AND SEWER DIST MT0000014 | BASIN | 200 | — | — | Compliant |
| RED WHEEL TRAILER COURT MT0000024 | GREAT FALLS | 200 | — | — | Compliant |
| BEARCREEK MUNICIPAL WATER SYS MT0000063 | RED LODGE | 200 | — | — | Compliant |
| BABB WATER USERS ASSN MT0000019 | BABB | 200 | — | — | Compliant |
| LIBBY DAM PROJECT SEATTLE DIST MT0000273 | LIBBY | 200 | — | — | Compliant |
| OAK RIDGE ESTATES MT0004250 | BILLINGS | 200 | — | — | Compliant |
| LOMA COUNTY WATER DISTRICT MT0002669 | LOMA | 200 | — | — | Compliant |
| GALATA COUNTY WATER DISTRICT MT0000009 | GALATA | 200 | — | — | Compliant |
| KOUNTZ TRAILER COURT MT0001788 | BOZEMAN | 200 | — | — | Compliant |
| BROADVIEW TOWN OF MT0000167 | BROADVIEW | 200 | — | — | Compliant |
| INDIAN WATER USERS ASSOC. MT0000207 | ELMO | 200 | — | — | Compliant |
| EAST GLACIER PARK CO MT0000205 | EAST GLACIER | 200 | — | — | Compliant |
| MISSION MEADOWS RV CAMPSITE PARK, INC. MT0000621 | MISSOULA | 200 | — | — | Compliant |
| AQUA GOAT LLC MT0005161 | BILLINGS | 200 | — | — | Compliant |
| MUDDY CLUSTER WATER SYSTEM 083090065 | LAME DEER | 195 | — | — | Compliant |
| VALLEY GARDEN GOLF VILLAGE HOA MT0003597 | ENNIS | 195 | — | — | Compliant |
| GREENWOOD VILLAGE RV AND MHP MT0003602 | KALISPELL | 195 | — | — | Compliant |
| TWO BUTTES WATER USERS ASSN MT0000219 | FORT SHAW | 195 | — | — | Compliant |
| PINE HILLS YOUTH CORRECT FACIL MT0000292 | MILES CITY | 193 | — | — | Compliant |
| STAR MOBILE HOME PARK MT0000034 | BOZEMAN | 190 | — | — | Compliant |
| SUNSET WEST DEVELOPMENT MT0000383 | MISSOULA | 190 | — | — | Compliant |
| STILL RIVER ESTATES SUBDIVISION MT0005118 | BILLINGS | 188 | — | — | Compliant |
| WINNETT TOWN OF MT0000364 | WINNETT | 187 | — | — | Compliant |
| MOORE TOWN OF MT0000295 | MOORE | 186 | — | — | Compliant |
| PELE PARK MT0000593 | EAST HELENA | 186 | — | — | Compliant |
| RAMSHORN VIEW ESTATES MT0004035 | TOWNSEND | 185 | — | — | Compliant |
| HINGHAM WATER USERS MT0003124 | HINGHAM | 181 | — | — | Compliant |
| DAVIS MEADOW VILLAGE MT0003990 | EAST HELENA | 180 | — | — | Compliant |
| SANGSTER WATER HAULING LLC MT0003551 | GREAT FALLS | 180 | — | — | Compliant |
| GOLDEN AGE VILLAGE MT0003313 | EMIGRANT | 180 | — | — | Compliant |
| BAIR CLARK PROPERTIES, LLC MT0000374 | MISSOULA | 180 | — | — | Compliant |
| RICHEY TOWN OF MT0000316 | RICHEY | 180 | — | — | Compliant |
| SAND COULEE WATER USERS DISTRICT MT0000325 | SAND COULEE | 180 | — | — | Compliant |
| INDIAN WATER USERS ASSN MT0000324 | SAINT IGNATIUS | 180 | — | — | Compliant |
| TAMARACK WOODS HOA LAKESIDE MT0003393 | KALISPELL | 180 | — | — | Compliant |
| SACO TOWN OF MT0000323 | SACO | 180 | — | — | Compliant |
| CASITAS DEL MESA MHP MT0002738 | GLENDIVE | 180 | — | — | Compliant |
| CHERRY CREEK WUA GLASGOW MT0000228 | GLASGOW | 180 | — | — | Compliant |
| FOREST PARK TRAILER COURT #2 MT0001367 | BOZEMAN | 175 | — | — | Compliant |
| MOUNTAIN HERITAGE WATER SYSTEM MT0002873 | HELENA | 175 | — | — | Compliant |
| ELK MEADOWS RANCHETTES MT0000632 | HUSON | 175 | — | — | Compliant |
| FISCHER'S TRAILER COURT MT0000026 | GREAT FALLS | 175 | — | — | Compliant |
| KOOTENAI CREEK VILLAGE MT0004241 | HAMILTON | 175 | — | — | Compliant |
| TOWN VIEW ESTATES WUA INC MT0002172 | HELENA | 175 | — | — | Compliant |
| MOBILE CITY TRAILER COURT MT0000646 | MISSOULA | 175 | — | — | Compliant |
| CINNABAR THE MT0001557 | GARDINER | 175 | — | — | Compliant |
| WESTBY TOWN OF MT0000355 | WESTBY | 172 | — | — | Compliant |
| AZURE VS GW 083090071 | BOX ELDER | 171 | — | — | Compliant |