EPA Air · stack tests by county and year
Air-emissions stack tests in Natrona County, Wyoming, 2025
- 22Stack tests
A stack test measures what a source actually emits, at the stack, against the limit in its permit. Each row below is one stack test recorded against a source in Natrona County, Wyoming during 2025. A facility can appear several times: this is the year’s record of what happened, not a list of places. The sources themselves are on the Natrona County facility page.
Natrona County, Wyoming, 2025
Air-emissions stack tests in Natrona County, other years
Air-emissions stack tests recorded in Natrona County, Wyoming, 2025
| Date | Facility | Kind | Agency |
|---|---|---|---|
| 2025-11-25 | CASPER REFINERY (HF SINCLAIR CASPER REFINING LLC) — high-priority violation on file | Pass | State |
| 2025-11-25 | CASPER REFINERY (HF SINCLAIR CASPER REFINING LLC) — high-priority violation on file | Pass | State |
| 2025-11-24 | CASPER REFINERY (HF SINCLAIR CASPER REFINING LLC) — high-priority violation on file | Pass | State |
| 2025-10-17 | CASPER REFINERY (HF SINCLAIR CASPER REFINING LLC) — high-priority violation on file | Pass | State |
| 2025-10-16 | CASPER REFINERY (HF SINCLAIR CASPER REFINING LLC) — high-priority violation on file | Pass | State |
| 2025-10-15 | CASPER COMPRESSOR STATION (TALLGRASS INTERSTATE GAS TRANSMISSION) | Pass | State |
| 2025-10-15 | CASPER COMPRESSOR STATION (TALLGRASS INTERSTATE GAS TRANSMISSION) | Pass | State |
| 2025-10-15 | CASPER COMPRESSOR STATION (TALLGRASS INTERSTATE GAS TRANSMISSION) | Pass | State |
| 2025-10-15 | CASPER COMPRESSOR STATION (TALLGRASS INTERSTATE GAS TRANSMISSION) | Pass | State |
| 2025-10-15 | CASPER COMPRESSOR STATION (TALLGRASS INTERSTATE GAS TRANSMISSION) | Pass | State |
| 2025-10-15 | CASPER COMPRESSOR STATION (TALLGRASS INTERSTATE GAS TRANSMISSION) | Pass | State |
| 2025-10-15 | CASPER COMPRESSOR STATION (TALLGRASS INTERSTATE GAS TRANSMISSION) | Pass | State |
| 2025-10-15 | CASPER COMPRESSOR STATION (TALLGRASS INTERSTATE GAS TRANSMISSION) | Pass | State |
| 2025-10-15 | CASPER COMPRESSOR STATION (TALLGRASS INTERSTATE GAS TRANSMISSION) | Pass | State |
| 2025-10-15 | CASPER COMPRESSOR STATION (TALLGRASS INTERSTATE GAS TRANSMISSION) | Pass | State |
| 2025-10-15 | CASPER COMPRESSOR STATION (TALLGRASS INTERSTATE GAS TRANSMISSION) | Pass | State |
| 2025-10-15 | CASPER COMPRESSOR STATION (TALLGRASS INTERSTATE GAS TRANSMISSION) | Pass | State |
| 2025-10-08 | CASPER REFINERY (HF SINCLAIR CASPER REFINING LLC) — high-priority violation on file | Fail | State |
| 2025-10-07 | CASPER REFINERY (HF SINCLAIR CASPER REFINING LLC) — high-priority violation on file | Fail | State |
| 2025-02-10 | CASPER REFINERY (HF SINCLAIR CASPER REFINING LLC) — high-priority violation on file | Pass | State |
| 2025-02-10 | CASPER REFINERY (HF SINCLAIR CASPER REFINING LLC) — high-priority violation on file | Pass | State |
| 2025-02-10 | CASPER REFINERY (HF SINCLAIR CASPER REFINING LLC) — high-priority violation on file | Pass | State |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.