Tapcensus

All water systems in Montana

2,352 systems

SystemServesStatusRules violated, 3 yrUnresolved
Billings City of
Billings · Yellowstone County 		114,000 0 0
Missoula Water
Missoula · Missoula County 		68,200 0 0
Great Falls City of
Great Falls · Cascade County 		60,000 0 0
Bozeman City of
Bozeman · Gallatin County 		56,000 0 0
Butte Silverbow Water Dept
Butte · Silver Bow County 		33,000 2 0
Helena Water System
Helena · Lewis and Clark County 		32,091 0 0
Kalispell Public Works
Kalispell · Flathead County 		25,000 0 0
Montana State University Bozeman
Bozeman · Gallatin County 		19,200 0 0
University of Montana
Missoula · Missoula County 		15,000 1 0
Billings Heights CO Water Dist of
Billings · Yellowstone County 		12,000 3 0
Belgrade City of
Belgrade · Gallatin County 		10,460 0 0
Whitefish City of
Whitefish · Flathead County 		10,418 0 0
Havre City of
Havre · Hill County 		9,921 5 0
West Yellowstone Town of
West Yellowstone · Gallatin County 		9,899 0 0
Miles City City of
Miles City · Custer County 		9,565 2 0
Flathead County Water and Sewer
Kalispell · Flathead County 		9,520 1 0
Livingston City of
Livingston · Park County 		9,200 0 0
Malmstrom Air Force Base
Great Falls · Cascade County 		8,850 3 0
Anaconda Water Department
Anaconda · Deer Lodge County 		6,750 1 0
Laurel Municipal Water System
Laurel · Yellowstone County 		6,339 1 0
Bigfork County Water and Sewer
Bigfork · Flathead County 		6,100 0 0
Lewistown City of
Lewistown · Fergus County 		5,923 1 0
Lockwood Water and Sewer District
Billings · Yellowstone County 		5,900 0 0
Rocky Mountain College
Billings · Yellowstone County 		5,700 0 0
Hamilton City of
Hamilton · Ravalli County 		5,660 0 0
Polson City of
Polson · Lake County 		5,300 2 0
Sidney City of
Sidney · Richland County 		5,000 0 0
Libby City of
Libby · Lincoln County 		4,892 1 0
Glendive City of
Glendive · Dawson County 		4,873 0 0
Town of Browning
County 		4,671 1 0
Columbia Falls City of
Columbia Falls · Flathead County 		4,450 0 0
North Star Zoot Water
Bozeman · Gallatin County 		4,323 0 0
Dillon City of
Dillon · Beaverhead County 		4,300 0 0
River Rock County Water and Sewer Dist
Belgrade · Gallatin County 		4,200 2 0
Big Sky County Water and Sewer Dist 363
Big Sky · Madison County 		4,132 1 0
Shelby City of
Shelby · Toole County 		3,970 1 1
Hardin City of
Hardin · Big Horn County 		3,500 1 0
Ridge Run
Flathead County 		3,500 0 0
Lolo Water and Sewer Dist
Lolo · Missoula County 		3,315 1 0
Quartz Flat Rest Stop East
Superior · Mineral County 		3,301 1 0
Quartz Flat Rest Stop West
Superior · Mineral County 		3,301 1 0
Glasgow City of
Glasgow · Valley County 		3,253 1 0
Montana Technological University
Butte · Silver Bow County 		3,200 1 0
Cut Bank City of
Cut Bank · Glacier County 		3,105 1 0
Poplar, City of
County 		3,025 5 2
Source Giant Springs INC
Great Falls · Cascade County 		3,007 1 0
Dry Prairie Rural Water Authority
Culbertson · Roosevelt County 		3,005 2 0
Dena Mora Saltese East Rest
Saltese · Mineral County 		3,000 2 0
Wolf Point City of
County 		3,000 0 0
Montana State University Billings
Billings · Yellowstone County 		2,999 0 0
About this data

Rules violated counts the rules a system was in violation of in the past three years, including monitoring and reporting lapses; one rule can carry several violations. Unresolved is the number of those rules still in violation at EPA's latest data refresh.

Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Montana records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.