EPA Air · stack tests by state, industry and year
Primary metal manufacturing (NAICS 3314): stack tests in Montana, 2025
- 3Stack 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 3314. A facility filing more than one industry code is counted under the first one on its record.
Primary metal manufacturing (NAICS 3314) in Montana, other years
Other industries in Montana, 2025
- Pipeline transportation (NAICS 4862) 54
- Petroleum and coal products manufacturing (NAICS 3241) 42
- Utilities (NAICS 2211) 42
- Oil and gas extraction (NAICS 2111) 12
- Food manufacturing (NAICS 3113) 5
- National security and international affairs (NAICS 9281) 3
Air-emissions stack tests recorded in Montana, 2025
| Date | Facility | Where | Kind | Agency |
|---|---|---|---|---|
| 2025-06-02 | STILLWATER MINING CO SMELTER | COLUMBUS, Stillwater, MT | Pass | State |
| 2025-06-02 | STILLWATER MINING CO SMELTER | COLUMBUS, Stillwater, MT | Pass | State |
| 2025-06-02 | STILLWATER MINING CO SMELTER | COLUMBUS, Stillwater, 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.