EPA Air · stack tests by county and year
Air-emissions stack tests in Crook County, Wyoming, 2026
- 4Stack 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 Crook County, Wyoming during 2026. 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 Crook County facility page.
Air-emissions stack tests in Crook County, other years
Air-emissions stack tests recorded in Crook County, Wyoming, 2026
| Date | Facility | Kind | Agency |
|---|---|---|---|
| 2026-05-11 | COLONY PLANT (BENTONITE PERFORMANCE MINERALS) | Pass | State |
| 2026-01-29 | COLONY PLANT (BENTONITE PERFORMANCE MINERALS) | Pass | State |
| 2026-01-29 | COLONY PLANT (BENTONITE PERFORMANCE MINERALS) | Pass | State |
| 2026-01-29 | COLONY PLANT (BENTONITE PERFORMANCE MINERALS) | Pass | State |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.
What this page shows
This page covers Clean Air Act facilities in the EPA air register with stack tests in Crook county, WY, for 2026. It lists 4 stack tests recorded in 2026.