EPA Air · stack tests by state, industry and year
Petroleum and coal products manufacturing (NAICS 3241): stack tests in Montana, 2026
- 29Stack 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 2026 at a Montana source whose primary industry code is NAICS 3241. A facility filing more than one industry code is counted under the first one on its record.
Petroleum and coal products manufacturing (NAICS 3241) in Montana, other years
Other industries in Montana, 2026
- Utilities (NAICS 2211) 31
- Pipeline transportation (NAICS 4862) 17
- Nonmetallic mineral product manufacturing (NAICS 3273) 5
- Mining support (NAICS 2131) 4
- Merchant wholesalers, nondurable goods (NAICS 4247) 3
Air-emissions stack tests recorded in Montana, 2026
| Date | Facility | Where | Kind | Agency |
|---|---|---|---|---|
| 2026-08-17 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2026-08-13 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2026-08-13 | PAR MONTANA BILLINGS REFINERY | BILLINGS, Yellowstone, MT | Pass | State |
| 2026-08-13 | PAR MONTANA BILLINGS REFINERY | BILLINGS, Yellowstone, MT | Pass | State |
| 2026-08-13 | PAR MONTANA BILLINGS REFINERY | BILLINGS, Yellowstone, MT | Pass | State |
| 2026-08-11 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2026-08-05 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2026-08-05 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2026-08-05 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2026-08-04 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2026-08-04 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Fail | State |
| 2026-07-20 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2026-07-20 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2026-07-20 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2026-04-27 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2026-04-27 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2026-04-27 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2026-04-27 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2026-04-01 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2026-04-01 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2026-04-01 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2026-04-01 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2026-02-17 | PAR MONTANA BILLINGS REFINERY | BILLINGS, Yellowstone, MT | Pass | State |
| 2026-02-09 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2026-02-09 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2026-02-09 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2026-01-29 | PAR MONTANA BILLINGS REFINERY | BILLINGS, Yellowstone, MT | Pass | State |
| 2026-01-07 | BILLINGS REFINERY | BILLINGS, Yellowstone, MT | Pass | State |
| 2026-01-06 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, 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.