EPA Air · stack tests by county and year
Air-emissions stack tests in Douglas County, Wisconsin, 2026
- 9Stack 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 Douglas County, Wisconsin 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 Douglas County facility page.
Douglas County, Wisconsin, 2026
Air-emissions stack tests in Douglas County, other years
Air-emissions stack tests recorded in Douglas County, Wisconsin, 2026
| Date | Facility | Kind | Agency |
|---|---|---|---|
| 2026-04-09 | SUPERIOR REFINING COMPANY LLC — high-priority violation on file | Pass | State |
| 2026-04-09 | SUPERIOR REFINING COMPANY LLC — high-priority violation on file | Pass | State |
| 2026-04-08 | SUPERIOR REFINING COMPANY LLC — high-priority violation on file | Pass | State |
| 2026-04-07 | SUPERIOR REFINING COMPANY LLC — high-priority violation on file | Pass | State |
| 2026-02-27 | GRAYMONT (WI) LLC — high-priority violation on file | Pass | State |
| 2026-02-05 | SUPERIOR REFINING COMPANY LLC — high-priority violation on file | Pass | State |
| 2026-02-04 | SUPERIOR REFINING COMPANY LLC — high-priority violation on file | Pass | State |
| 2026-02-04 | SUPERIOR REFINING COMPANY LLC — high-priority violation on file | Pass | State |
| 2026-02-03 | SUPERIOR REFINING COMPANY 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.