EPA Air · stack tests by state and year
Air-emissions stack tests in Montana, 2023
- 177Stack tests
A stack test measures what a source actually emits, at the stack, against the limit in its permit. Every stack test below was recorded against a source in Montana during 2023; one facility can appear more than once, because this is a record of what happened rather than a list of places.
Counties in Montana, 2023
- Yellowstone County 51
- Rosebud County 24
- Cascade County 17
- Big Horn County 14
- Glacier County 11
- Silver Bow County 9
- Flathead County 8
- Fallon County 7
- Deer Lodge County 6
- Valley County 5
- Jefferson County 4
- Gallatin County 3
- Richland County 3
- Stillwater County 3
- Roosevelt County 3
Montana, other years
Air-emissions stack tests recorded in Montana, 2023
| Date | Facility | Where | Kind | Agency |
|---|---|---|---|---|
| 2023-12-26 | ROCKY MOUNTAIN POWER | HARDIN, Big Horn, MT | Pass | State |
| 2023-12-26 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2023-12-26 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2023-12-21 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2023-12-15 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2023-12-15 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2023-12-15 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2023-12-15 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2023-12-15 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2023-12-15 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2023-12-15 | COLSTRIP ENERGY LTD PARTNERSHIP | COLSTRIP, Rosebud, MT | Pass | State |
| 2023-12-15 | COLSTRIP ENERGY LTD PARTNERSHIP | COLSTRIP, Rosebud, MT | Pass | State |
| 2023-12-15 | COLSTRIP ENERGY LTD PARTNERSHIP | COLSTRIP, Rosebud, MT | Pass | State |
| 2023-12-15 | COLSTRIP ENERGY LTD PARTNERSHIP | COLSTRIP, Rosebud, MT | Pass | State |
| 2023-11-28 | ROCKY MOUNTAIN POWER | HARDIN, Big Horn, MT | Pass | State |
| 2023-11-28 | WILLISTON BASIN - CABIN CREEK | BAKER, Fallon, MT | Pass | State |
| 2023-11-16 | BILLINGS REFINERY | BILLINGS, Yellowstone, MT | Pass | State |
| 2023-11-13 | MDU - GLENDIVE | GLENDIVE, Dawson, MT | Pass | State |
| 2023-11-13 | MDU - GLENDIVE | GLENDIVE, Dawson, MT | Pass | State |
| 2023-11-09 | NORTHWESTERN ENERGY MAINLINE #1 | CUT BANK, Glacier, MT | Pass | State |
| 2023-11-09 | NORTHWESTERN ENERGY MAINLINE #1 | CUT BANK, Glacier, MT | Pass | State |
| 2023-11-09 | NORTHWESTERN ENERGY MAINLINE #1 | CUT BANK, Glacier, MT | Pass | State |
| 2023-11-09 | NORTHWESTERN ENERGY MAINLINE #1 | CUT BANK, Glacier, MT | Pass | State |
| 2023-11-09 | NORTHWESTERN ENERGY MAINLINE #1 | CUT BANK, Glacier, MT | Pass | State |
| 2023-11-02 | BILLINGS REFINERY | BILLINGS, Yellowstone, MT | Pass | State |
| 2023-11-02 | MONTANA SULPHUR & CHEMICAL | BILLINGS, Yellowstone, MT | Pass | State |
| 2023-11-01 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2023-11-01 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2023-11-01 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2023-11-01 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2023-11-01 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2023-11-01 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2023-10-31 | WEYERHAEUSER-CFALLS — high-priority violation on file | COLUMBIA FALLS, Flathead, MT | Pass | State |
| 2023-10-31 | WEYERHAEUSER-CFALLS — high-priority violation on file | COLUMBIA FALLS, Flathead, MT | Pass | State |
| 2023-10-31 | WEYERHAEUSER-CFALLS — high-priority violation on file | COLUMBIA FALLS, Flathead, MT | Pass | State |
| 2023-10-31 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2023-10-31 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2023-10-18 | WILLISTON BASIN - HATHAWAY STATION | HATHAWAY, Rosebud, MT | Pass | State |
| 2023-10-18 | WILLISTON BASIN - FORT PECK STATION | NASHUA, Valley, MT | Pass | State |
| 2023-10-18 | WILLISTON BASIN - FORT PECK STATION | NASHUA, Valley, MT | Pass | State |
| 2023-10-12 | ROCKY MOUNTAIN POWER | HARDIN, Big Horn, MT | Pass | State |
| 2023-10-12 | PAR MONTANA BILLINGS REFINERY | BILLINGS, Yellowstone, MT | Pass | State |
| 2023-10-09 | ROCKY MOUNTAIN POWER | HARDIN, Big Horn, MT | Pass | State |
| 2023-10-09 | ROCKY MOUNTAIN POWER | HARDIN, Big Horn, MT | Pass | State |
| 2023-10-06 | ROCKY MOUNTAIN POWER | HARDIN, Big Horn, MT | Pass | State |
| 2023-10-06 | BILLINGS REFINERY | BILLINGS, Yellowstone, MT | Pass | State |
| 2023-10-05 | YELLOWSTONE POWER PLANT — high-priority violation on file | BILLINGS, Yellowstone, MT | Pass | State |
| 2023-09-15 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2023-09-15 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2023-09-15 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2023-09-15 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2023-09-14 | BAKKEN GATHERING PLANT | SIDNEY, Richland, MT | Pass | State |
| 2023-09-11 | CHARLIE CREEK COMPRESSOR STATION | LAMBERT, Richland, MT | Pass | State |
| 2023-09-11 | CHARLIE CREEK COMPRESSOR STATION | LAMBERT, Richland, MT | Pass | State |
| 2023-09-05 | SUN MOUNTAIN LUMBER | DEER LODGE, Powell, MT | Pass | State |
| 2023-08-25 | N. BORDER PIPELINE CO STA. 3 | CULBERTSON, Roosevelt, MT | Pass | State |
| 2023-08-21 | ROCKY MOUNTAIN POWER | HARDIN, Big Horn, MT | Pass | State |
| 2023-08-21 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2023-08-21 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2023-08-21 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2023-08-21 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2023-08-21 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2023-08-15 | MONTANA SULPHUR & CHEMICAL | BILLINGS, Yellowstone, MT | Pass | State |
| 2023-08-15 | MONTANA SULPHUR & CHEMICAL | BILLINGS, Yellowstone, MT | Pass | State |
| 2023-08-15 | MONTANA SULPHUR & CHEMICAL | BILLINGS, Yellowstone, MT | Pass | State |
| 2023-08-09 | WEYERHAEUSER-CFALLS — high-priority violation on file | COLUMBIA FALLS, Flathead, MT | Pass | State |
| 2023-07-25 | PAR MONTANA BILLINGS REFINERY | BILLINGS, Yellowstone, MT | Pass | State |
| 2023-07-21 | YELLOWSTONE POWER PLANT — high-priority violation on file | BILLINGS, Yellowstone, MT | Pass | State |
| 2023-07-20 | ASH GROVE CEMENT | CLANCY, Jefferson, MT | Pass | State |
| 2023-07-20 | ASH GROVE CEMENT | CLANCY, Jefferson, MT | Pass | State |
| 2023-07-20 | ASH GROVE CEMENT | CLANCY, Jefferson, MT | Pass | State |
| 2023-07-20 | ASH GROVE CEMENT | CLANCY, Jefferson, MT | Pass | State |
| 2023-07-17 | WEYERHAEUSER-CFALLS — high-priority violation on file | COLUMBIA FALLS, Flathead, MT | Pass | State |
| 2023-07-17 | WEYERHAEUSER-CFALLS — high-priority violation on file | COLUMBIA FALLS, Flathead, MT | Pass | State |
| 2023-07-10 | ROCKY MOUNTAIN LABORATORIES FACILITY | HAMILTON, Ravalli, MT | Pass | State |
| 2023-07-10 | ROCKY MOUNTAIN LABORATORIES FACILITY | HAMILTON, Ravalli, MT | Pass | State |
| 2023-07-10 | STILLWATER MINING CO SMELTER | COLUMBUS, Stillwater, MT | Pass | State |
| 2023-07-10 | STILLWATER MINING CO SMELTER | COLUMBUS, Stillwater, MT | Pass | State |
| 2023-07-10 | STILLWATER MINING CO SMELTER | COLUMBUS, Stillwater, MT | Pass | State |
| 2023-07-06 | WILLISTON BASIN - HATHAWAY STATION | HATHAWAY, Rosebud, MT | Pass | State |
| 2023-07-06 | WILLISTON BASIN - FORT PECK STATION | NASHUA, Valley, MT | Pass | State |
| 2023-07-06 | WILLISTON BASIN - FORT PECK STATION | NASHUA, Valley, MT | Pass | State |
| 2023-06-30 | DRY CREEK FIELD STATION 056 | RED LODGE, Carbon, MT | Pass | State |
| 2023-06-22 | PAR MONTANA BILLINGS REFINERY | BILLINGS, Yellowstone, MT | Pass | State |
| 2023-06-22 | PAR MONTANA BILLINGS REFINERY | BILLINGS, Yellowstone, MT | Pass | State |
| 2023-06-22 | PAR MONTANA BILLINGS REFINERY | BILLINGS, Yellowstone, MT | Pass | State |
| 2023-06-16 | PAR MONTANA BULK TERMINAL | BILLINGS, Yellowstone, MT | Pass | State |
| 2023-06-02 | SUN MOUNTAIN LUMBER | DEER LODGE, Powell, MT | Fail | State |
| 2023-05-10 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2023-05-10 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2023-05-08 | NORTHWESTERN ENERGY MAINLINE #1 | CUT BANK, Glacier, MT | Pass | State |
| 2023-05-08 | NORTHWESTERN ENERGY MAINLINE #1 | CUT BANK, Glacier, MT | Pass | State |
| 2023-05-08 | NORTHWESTERN ENERGY MAINLINE #1 | CUT BANK, Glacier, MT | Pass | State |
| 2023-05-08 | NORTHWESTERN ENERGY MAINLINE #1 | CUT BANK, Glacier, MT | Pass | State |
| 2023-05-08 | NORTHWESTERN ENERGY MAINLINE #1 | CUT BANK, Glacier, MT | Pass | State |
| 2023-05-08 | NORTHWESTERN ENERGY MAINLINE #1 | CUT BANK, Glacier, MT | Pass | State |
| 2023-05-03 | WILLISTON BASIN - HATHAWAY STATION | HATHAWAY, Rosebud, MT | Pass | State |
| 2023-05-03 | WILLISTON BASIN - CABIN CREEK | BAKER, Fallon, MT | Pass | State |
| 2023-04-24 | ROCKY MOUNTAIN POWER | HARDIN, Big Horn, MT | Pass | State |
| 2023-04-21 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
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Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.