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.
Health effects: The combined limit protects against methemoglobinemia — the same risk as nitrate alone and nitrite alone. In infants under 6 months, gut bacteria convert these nitrogen compounds to forms that block oxygen transport in blood ('blue baby syndrome'). Pregnant women and individuals with certain enzyme deficiencies are also at elevated risk.
Systems with a Nitrate-Nitrite (Combined) violation
Latest quarter first, then largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Spring Creek Coal Domestic Decker · Big Horn County |
200 | 1 | 0 | |
|
Corral Bar INC Gallatin Gateway · Gallatin County |
195 | 1 | 0 | |
|
Cskt Division of Fire Management County |
190 | 7 | 1 | |
|
Days Inn Missoula Airport Missoula · Missoula County |
190 | 1 | 0 | |
|
Winnett Town of Winnett · Petroleum County |
187 | 8 | 1 | |
|
Cherry Creek Wua Glasgow Glasgow · Valley County |
180 | 5 | 0 | |
|
Simms High School Simms · Cascade County |
180 | 3 | 0 | |
|
Ivanhoe Water INC Polson · Lake County |
178 | 2 | 0 | |
|
Big Sky SD Ophir Elementary School Gallatin Gateway · Gallatin County |
175 | 3 | 0 | |
|
Hellgate Campground Helena · Lewis and Clark County |
175 | 3 | 1 | |
|
Florence Carlton Community Church Florence · Missoula County |
172 | 1 | 0 | |
|
Hoving Business Center Helena · Lewis and Clark County |
170 | 5 | 1 | |
|
Fox Hill Estates Kalispell · Flathead County |
163 | 1 | 0 | |
|
Wingate by Wyndham Butte · Silver Bow County |
160 | 3 | 0 | |
|
Joes in and Out Malta · Phillips County |
152 | 2 | 0 | |
|
Anaconda Country Club Anaconda · Deer Lodge County |
150 | 2 | 0 | |
|
Court Sheriff Campground Helena · Lewis and Clark County |
150 | 2 | 0 | |
|
Greycliff Mill Greycliff · Sweet Grass County |
150 | 2 | 0 | |
|
Hamilton Golf Club Snack Shop Hamilton · Ravalli County |
150 | 1 | 0 | |
|
Island Mountain Development Group County |
150 | 3 | 0 | |
|
Lambert Sewer and Water Assn Lambert · Richland County |
150 | 4 | 0 | |
|
Teton Pass Ski Area INC Choteau · Teton County |
150 | 2 | 0 | |
|
Trailhead Christian Fellowship Church Townsend · Broadwater County |
150 | 1 | 0 | |
|
Mission Valley Amish Church County |
147 | 2 | 0 | |
|
Philipsburg Bay Campground Philipsburg · Granite County |
138 | 2 | 0 | |
|
MT Steakhouse Lincoln · Lewis and Clark County |
133 | 3 | 1 | |
|
Terry High School District NO 5 Terry · Prairie County |
133 | 3 | 0 | |
|
Pine Meadows Golf Course Elks 456 the Lewistown · Fergus County |
130 | 2 | 0 | |
|
Sage Creek Colony Chester · Liberty County |
130 | 2 | 0 | |
|
Beaver Creek Golf Course Havre · Hill County |
128 | 2 | 0 | |
|
Bruckner Truck and Equipment Missoula · Missoula County |
125 | 2 | 0 | |
|
Pleasant Park Community INC Great Falls · Cascade County |
125 | 3 | 0 | |
|
Arrowhead School District NO 75 Pray · Park County |
120 | 2 | 0 | |
|
Coal Banks Landing Blm Lewistown · Chouteau County |
120 | 2 | 0 | |
|
Dodson Town of Dodson · Phillips County |
120 | 5 | 1 | |
|
Sun Life Health Foods Kalispell · Flathead County |
120 | 2 | 0 | |
|
Joe & Dee's Glendive · Dawson County |
120 | 2 | 0 | |
|
Madison Valley Baptist Church Unapproved Ennis · Madison County |
120 | 1 | 0 | |
|
Travelers Rest Ropers Lounge Lolo · Missoula County |
120 | 2 | 0 | |
|
Tally Lake Campground Kalispell · Flathead County |
117 | 1 | 0 | |
|
Sidney Richland County Airport Unapprove Sidney · Richland County |
115 | 2 | 0 | |
|
ST Anthony Orthodox Church Bozeman · Gallatin County |
115 | 2 | 0 | |
|
Terry Downtown Wua Terry · Prairie County |
115 | 2 | 0 | |
|
Montana Frontier Cafe Stevensville · Ravalli County |
110 | 2 | 0 | |
|
Craig Bar Wolf Creek · Lewis and Clark County |
108 | 2 | 0 | |
|
Madison County Golf Assoc Ennis · Madison County |
108 | 1 | 0 | |
|
Souths Country Store Helena · Lewis and Clark County |
108 | 2 | 1 | |
|
Bear's Lair Florence · Ravalli County |
107 | 2 | 0 | |
|
Wye West Lounge Missoula · Missoula County |
106 | 2 | 0 | |
|
F H Stoltze Land and Lumber CO Columbia Falls · Flathead County |
105 | 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.