EPA Air · stack tests by county and year
Air-emissions stack tests in Porter County, Indiana, 2025
- 54Stack 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 Porter County, Indiana 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 Porter County facility page.
Porter County, Indiana, 2025
Air-emissions stack tests in Porter County, other years
Air-emissions stack tests recorded in Porter County, Indiana, 2025
| Date | Facility | Kind | Agency |
|---|---|---|---|
| 2025-11-18 | CLEVELAND-CLIFFS BURNS HARBOR LLC — high-priority violation on file | Pass | State |
| 2025-10-09 | URSCHEL LABORATORIES INC | Pass | State |
| 2025-10-09 | URSCHEL LABORATORIES INC | Pass | State |
| 2025-10-09 | URSCHEL LABORATORIES INC | Pass | State |
| 2025-10-09 | URSCHEL LABORATORIES INC | Pass | State |
| 2025-10-08 | URSCHEL LABORATORIES INC | Pass | State |
| 2025-10-08 | URSCHEL LABORATORIES INC | Pass | State |
| 2025-10-08 | URSCHEL LABORATORIES INC | Pass | State |
| 2025-10-08 | URSCHEL LABORATORIES INC | Pass | State |
| 2025-10-08 | URSCHEL LABORATORIES INC | Pass | State |
| 2025-10-08 | URSCHEL LABORATORIES INC | Pass | State |
| 2025-10-08 | URSCHEL LABORATORIES INC | Pass | State |
| 2025-10-08 | URSCHEL LABORATORIES INC | Pass | State |
| 2025-09-13 | NLMK INDIANA — high-priority violation on file | Pass | State |
| 2025-09-13 | NLMK INDIANA — high-priority violation on file | Pass | State |
| 2025-09-13 | NLMK INDIANA — high-priority violation on file | Pass | State |
| 2025-09-13 | NLMK INDIANA — high-priority violation on file | Pass | State |
| 2025-09-13 | NLMK INDIANA — high-priority violation on file | Pass | State |
| 2025-09-13 | NLMK INDIANA — high-priority violation on file | Pass | State |
| 2025-09-13 | NLMK INDIANA — high-priority violation on file | Pass | State |
| 2025-09-11 | NLMK INDIANA — high-priority violation on file | Pass | State |
| 2025-09-11 | NLMK INDIANA — high-priority violation on file | Pass | State |
| 2025-09-11 | NLMK INDIANA — high-priority violation on file | Pass | State |
| 2025-09-11 | NLMK INDIANA — high-priority violation on file | Fail | State |
| 2025-09-11 | NLMK INDIANA — high-priority violation on file | Pass | State |
| 2025-09-11 | NLMK INDIANA — high-priority violation on file | Fail | State |
| 2025-07-16 | CLEVELAND-CLIFFS BURNS HARBOR LLC — high-priority violation on file | Pass | State |
| 2025-07-16 | CLEVELAND-CLIFFS BURNS HARBOR LLC — high-priority violation on file | Pass | State |
| 2025-07-10 | CLEVELAND-CLIFFS BURNS HARBOR LLC — high-priority violation on file | Pass | State |
| 2025-07-10 | CLEVELAND-CLIFFS BURNS HARBOR LLC — high-priority violation on file | Pass | State |
| 2025-06-18 | O-N MINERALS (PORTAGE) COMPANY LLC DBA CARMEUSE LIME & STONE — high-priority violation on file | Pass | State |
| 2025-06-18 | O-N MINERALS (PORTAGE) COMPANY LLC DBA CARMEUSE LIME & STONE — high-priority violation on file | Pass | State |
| 2025-06-18 | O-N MINERALS (PORTAGE) COMPANY LLC DBA CARMEUSE LIME & STONE — high-priority violation on file | Pass | State |
| 2025-06-18 | O-N MINERALS (PORTAGE) COMPANY LLC DBA CARMEUSE LIME & STONE — high-priority violation on file | Pass | State |
| 2025-06-11 | U S STEEL MIDWEST PLANT | Pass | State |
| 2025-06-10 | U S STEEL MIDWEST PLANT | Pass | State |
| 2025-05-29 | MILESTONE CONTRACTORS LP | Pass | State |
| 2025-05-29 | MILESTONE CONTRACTORS LP | Pass | State |
| 2025-05-29 | MILESTONE CONTRACTORS LP | Pass | State |
| 2025-05-29 | MILESTONE CONTRACTORS LP | Pass | State |
| 2025-05-22 | PVS TECHNOLOGIES INC — high-priority violation on file | Pass | State |
| 2025-05-22 | PVS TECHNOLOGIES INC — high-priority violation on file | Pass | State |
| 2025-05-02 | O-N MINERALS (PORTAGE) COMPANY LLC DBA CARMEUSE LIME & STONE — high-priority violation on file | Fail | State |
| 2025-05-02 | O-N MINERALS (PORTAGE) COMPANY LLC DBA CARMEUSE LIME & STONE — high-priority violation on file | Fail | State |
| 2025-05-02 | O-N MINERALS (PORTAGE) COMPANY LLC DBA CARMEUSE LIME & STONE — high-priority violation on file | Fail | State |
| 2025-05-02 | O-N MINERALS (PORTAGE) COMPANY LLC DBA CARMEUSE LIME & STONE — high-priority violation on file | Pass | State |
| 2025-05-01 | O-N MINERALS (PORTAGE) COMPANY LLC DBA CARMEUSE LIME & STONE — high-priority violation on file | Pass | State |
| 2025-05-01 | O-N MINERALS (PORTAGE) COMPANY LLC DBA CARMEUSE LIME & STONE — high-priority violation on file | Pass | State |
| 2025-05-01 | O-N MINERALS (PORTAGE) COMPANY LLC DBA CARMEUSE LIME & STONE — high-priority violation on file | Pass | State |
| 2025-05-01 | O-N MINERALS (PORTAGE) COMPANY LLC DBA CARMEUSE LIME & STONE — high-priority violation on file | Pass | State |
| 2025-04-29 | CLEVELAND-CLIFFS BURNS HARBOR LLC — high-priority violation on file | Pass | State |
| 2025-04-16 | PVS TECHNOLOGIES INC — high-priority violation on file | Pass | State |
| 2025-04-16 | PVS TECHNOLOGIES INC — high-priority violation on file | Pass | State |
| 2025-01-27 | CLEVELAND-CLIFFS BURNS HARBOR 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.
What this page shows
This page covers Clean Air Act facilities in the EPA air register with stack tests in Porter county, IN, for 2025. It lists 54 stack tests recorded in 2025.