EPA Air · stack tests by county and year
Air-emissions stack tests in Butler County, Pennsylvania, 2026
- 12Stack 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 Butler County, Pennsylvania 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 Butler County facility page.
Butler County, Pennsylvania, 2026
Air-emissions stack tests in Butler County, other years
Air-emissions stack tests recorded in Butler County, Pennsylvania, 2026
| Date | Facility | Kind | Agency |
|---|---|---|---|
| 2026-07-23 | MARKWEST LIBERTY BLUESTONE LLC/TRILLITH COMP STA | Pass | State |
| 2026-07-22 | UGI MORAINE EAST GATHERING LLC/RENICK COMP STA | Pass | State |
| 2026-07-21 | MARKWEST LIBERTY BLUESTONE LLC/ROYAL OAK COMP STA | Pass | State |
| 2026-06-30 | PINE RUN MIDSTREAM LLC/BASS COMP STA | Pass | State |
| 2026-06-26 | COMMERCIAL ASPHALT SUPPLY/FENELTON | Fail | State |
| 2026-06-09 | MTN GATHERING LLC/FORWARD COMP STA | Pass | State |
| 2026-06-04 | VORTEQ COIL FINISHERS/VALENCIA PLT | Pass | State |
| 2026-05-21 | MARKWEST LIBERTY BLUESTONE LLC/VOLL COMP STA | Pass | State |
| 2026-05-19 | MARKWEST LIBERTY BLUESTONE LLC/BLUESTONE GAS PROC PLT | Pass | State |
| 2026-03-25 | ARMSTRONG CEMENT & SUPPLY/WINFIELD — high-priority violation on file | Pass | State |
| 2026-03-12 | MARKWEST LIBERTY BLUESTONE LLC/BLUESTONE GAS PROC PLT | Pass | State |
| 2026-03-04 | MARKWEST LIBERTY BLUESTONE LLC/VOLL COMP STA | Pass | State |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.