EPA Air · stack tests by state, industry and year
Utilities (NAICS 2211): stack tests in Montana, 2025
- 42Stack tests
A stack test measures what a source actually emits, at the stack, against the limit in its permit. Each row is one stack test recorded during 2025 at a Montana source whose primary industry code is NAICS 2211. A facility filing more than one industry code is counted under the first one on its record.
Utilities (NAICS 2211) in Montana, other years
Other industries in Montana, 2025
- Pipeline transportation (NAICS 4862) 54
- Petroleum and coal products manufacturing (NAICS 3241) 42
- Oil and gas extraction (NAICS 2111) 12
- Food manufacturing (NAICS 3113) 5
- National security and international affairs (NAICS 9281) 3
- Primary metal manufacturing (NAICS 3314) 3
Air-emissions stack tests recorded in Montana, 2025
| Date | Facility | Where | Kind | Agency |
|---|---|---|---|---|
| 2025-12-24 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2025-12-24 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2025-12-12 | FLATHEAD ELECTRIC LFGE FACILITY | KALISPELL, Flathead, MT | Pass | State |
| 2025-11-26 | MDU - GLENDIVE | GLENDIVE, Dawson, MT | Pass | State |
| 2025-11-18 | YELLOWSTONE COUNTY GENERATING STATION | LAUREL, Yellowstone, MT | Pass | State |
| 2025-10-24 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2025-10-16 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2025-10-16 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2025-08-07 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2025-08-07 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2025-07-23 | BASIN ELECTRIC POWER COOPERATIVE | BAINVILLE, Roosevelt, MT | Pass | State |
| 2025-07-23 | BASIN ELECTRIC POWER COOPERATIVE | BAINVILLE, Roosevelt, MT | Pass | State |
| 2025-07-02 | YELLOWSTONE POWER PLANT — high-priority violation on file | BILLINGS, Yellowstone, MT | Pass | State |
| 2025-05-30 | YELLOWSTONE POWER PLANT — high-priority violation on file | BILLINGS, Yellowstone, MT | Pass | State |
| 2025-05-20 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2025-05-20 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2025-05-02 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2025-04-29 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2025-04-29 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2025-04-29 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2025-04-29 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2025-04-28 | BASIN ELECTRIC POWER COOPERATIVE | BAINVILLE, Roosevelt, MT | Pass | State |
| 2025-04-28 | BASIN ELECTRIC POWER COOPERATIVE | BAINVILLE, Roosevelt, MT | Pass | State |
| 2025-04-25 | YELLOWSTONE POWER PLANT — high-priority violation on file | BILLINGS, Yellowstone, MT | Pass | State |
| 2025-04-25 | YELLOWSTONE POWER PLANT — high-priority violation on file | BILLINGS, Yellowstone, MT | Pass | State |
| 2025-04-10 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2025-04-10 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2025-04-07 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2025-04-07 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2025-03-21 | FLATHEAD ELECTRIC LFGE FACILITY | KALISPELL, Flathead, MT | Pass | State |
| 2025-03-03 | ROCKY MOUNTAIN POWER | HARDIN, Big Horn, MT | Pass | State |
| 2025-02-21 | BASIN CREEK POWER SERVICES | BUTTE, Silver Bow, MT | Pass | State |
| 2025-02-21 | BASIN CREEK POWER SERVICES | BUTTE, Silver Bow, MT | Pass | State |
| 2025-02-21 | BASIN CREEK POWER SERVICES | BUTTE, Silver Bow, MT | Pass | State |
| 2025-02-21 | BASIN CREEK POWER SERVICES | BUTTE, Silver Bow, MT | Pass | State |
| 2025-02-21 | BASIN CREEK POWER SERVICES | BUTTE, Silver Bow, MT | Pass | State |
| 2025-02-21 | BASIN CREEK POWER SERVICES | BUTTE, Silver Bow, MT | Pass | State |
| 2025-02-21 | BASIN CREEK POWER SERVICES | BUTTE, Silver Bow, MT | Pass | State |
| 2025-02-21 | BASIN CREEK POWER SERVICES | BUTTE, Silver Bow, MT | Pass | State |
| 2025-02-21 | BASIN CREEK POWER SERVICES | BUTTE, Silver Bow, MT | Pass | State |
| 2025-01-14 | ROCKY MOUNTAIN POWER | HARDIN, Big Horn, MT | Pass | State |
| 2025-01-13 | ROCKY MOUNTAIN POWER | HARDIN, Big Horn, MT | Pass | State |
Primary NAICS code as filed on the facility record; dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.