EPA Air · stack tests by county and year
Air-emissions stack tests in Flathead County, Montana, 2025
- 6Stack 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 Flathead County, Montana 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 Flathead County facility page.
Flathead County, Montana, 2025
Air-emissions stack tests in Flathead County, other years
Air-emissions stack tests recorded in Flathead County, Montana, 2025
| Date | Facility | Kind | Agency |
|---|---|---|---|
| 2025-12-17 | WEYERHAEUSER-EVERGREEN — high-priority violation on file | Pass | State |
| 2025-12-12 | FLATHEAD ELECTRIC LFGE FACILITY | Pass | State |
| 2025-11-19 | WEYERHAEUSER-EVERGREEN — high-priority violation on file | Fail | State |
| 2025-08-25 | WEYERHAEUSER-CFALLS — high-priority violation on file | Pass | State |
| 2025-08-12 | WEYERHAEUSER-CFALLS — high-priority violation on file | Fail | State |
| 2025-03-21 | FLATHEAD ELECTRIC LFGE FACILITY | 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 Flathead county, MT, in 2025. It lists 6 stack tests recorded in 2025.