Nitrate-Nitrite (Combined) violations in Montana
338 active public water systems in Montana had a Nitrate-Nitrite (Combined) violation in the past three years, 10 of them in the latest quarter of EPA's data. What Nitrate-Nitrite (Combined) is and why it matters.
Systems with a Nitrate-Nitrite (Combined) violation
Latest quarter first, then largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Hardin Eastbound Rest Area Hardin · Big Horn County |
877 | 1 | 0 | |
|
Hardin Westbound Rest Area Hardin · Big Horn County |
715 | 2 | 0 | |
|
Stokes Market Florence Florence · Ravalli County |
600 | 2 | 1 | |
|
Still River Estates Subdivision Billings · Yellowstone County |
188 | 3 | 0 | |
|
Moose Crossing INC Kalispell · Flathead County |
84 | 2 | 0 | |
|
King Ranch Colony Lewistown · Fergus County |
56 | 4 | 2 | |
|
Pops Inn Park City · Stillwater County |
50 | 2 | 0 | |
|
Centerville Bar Stockett · Cascade County |
40 | 2 | 0 | |
|
Buffalo Lodge Bar Dillon · Beaverhead County |
30 | 1 | 0 | |
|
Horse Prairie Campground West Dillon · Beaverhead County |
25 | 1 | 1 | |
|
Polson City of Polson · Lake County |
5,300 | 2 | 0 | |
|
Big Sky County Water and Sewer Dist 363 Big Sky · Madison County |
4,132 | 1 | 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 | |
|
Dena Mora Saltese East Rest Saltese · Mineral County |
3,000 | 2 | 1 | |
|
Lame Deer Water System County |
2,605 | 4 | 2 | |
|
Montana State Prison Deer Lodge · Powell County |
2,100 | 8 | 1 | |
|
Dena Mora Saltese West Rest Saltese · Mineral County |
2,000 | 3 | 0 | |
|
Roundup Water Department Roundup · Musselshell County |
1,900 | 1 | 0 | |
|
Malta City of Malta · Phillips County |
1,800 | 3 | 0 | |
|
Choteau City of Choteau · Teton County |
1,691 | 1 | 0 | |
|
Cenex Zip Trip Num 50 Park City · Stillwater County |
1,500 | 3 | 1 | |
|
Big Sky Conoco Travel Shoppe Big Sky · Gallatin County |
1,000 | 2 | 0 | |
|
Fairview Town of Fairview · Richland County |
1,000 | 2 | 0 | |
|
Deanos Travel Plaza Missoula · Missoula County |
959 | 2 | 0 | |
|
Oles Country Store Stevensville · Ravalli County |
820 | 2 | 0 | |
|
Dearborn N Craig Rest Stop Craig · Lewis and Clark County |
808 | 1 | 0 | |
|
Bears Country Store Libby · Lincoln County |
805 | 2 | 0 | |
|
Shepherd Schools Shepherd · Yellowstone County |
800 | 3 | 1 | |
|
Worden Ballantine Yellowstone Ballantine, Worden · Yellowstone County |
800 | 4 | 2 | |
|
Tiber County Water District Conrad · Pondera County |
750 | 5 | 0 | |
|
Montana State Hospital Complex Warm Springs · Deer Lodge County |
721 | 5 | 1 | |
|
Lost Trail Rest Area Sula · Ravalli County |
701 | 1 | 0 | |
|
ST Ignatius Town of St Ignatius · Lake County |
700 | 4 | 1 | |
|
ST Labre Indian School Ashland · Rosebud County |
650 | 3 | 0 | |
|
Sheridan Town of Sheridan · Madison County |
632 | 5 | 0 | |
|
Big Sandy Town of Big Sandy · Chouteau County |
608 | 2 | 0 | |
|
Elder Grove Middle School Bldg 6 Billings · Yellowstone County |
600 | 2 | 1 | |
|
Jefferson City South Rest Stop Jefferson City · Jefferson County |
600 | 2 | 0 | |
|
Town Pump Travel Plaza Glendive Glendive · Dawson County |
600 | 3 | 1 | |
|
Westgate Cenex Glendive · Dawson County |
600 | 2 | 0 | |
|
Wilson Foods Arlee · Lake County |
600 | 2 | 1 | |
|
Jim Darcy School District NO 1 Helena · Lewis and Clark County |
575 | 1 | 0 | |
|
Frenchtown High School Frenchtown · Missoula County |
550 | 5 | 0 | |
|
Wibaux Town of Wibaux · Wibaux County |
550 | 8 | 0 | |
|
Armington Jct Belt Rest Stop Belt · Cascade County |
510 | 2 | 0 | |
|
Fortine Mercantile Trego · Lincoln County |
504 | 2 | 0 | |
|
Earthquake Lake Visitor Center West Yellowstone · Madison County |
503 | 2 | 0 | |
|
Eddies Corner Moore · Fergus County |
503 | 2 | 0 |
About this data
A system is counted once if any of its violations in the past three years involved Nitrate-Nitrite (Combined), including monitoring and reporting lapses. Rules violated and status in the table are for the whole system, not Nitrate-Nitrite (Combined) alone.
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.