EPA Air · stack tests by county and year
Air-emissions stack tests in Washington County, Pennsylvania, 2026
- 29Stack 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 Washington 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 Washington County facility page.
Washington County, Pennsylvania, 2026
Air-emissions stack tests in Washington County, other years
Air-emissions stack tests recorded in Washington County, Pennsylvania, 2026
| Date | Facility | Kind | Agency |
|---|---|---|---|
| 2026-08-06 | EQT MIDSTREAM COMPANY LLC/DEEMSTON WICKS COMP STA | Pass | State |
| 2026-07-13 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/JOHNSTON COMP STA | Pass | State |
| 2026-07-01 | EQM GATHERING OPCO LLC/BLUE MOON COMP STA | Pass | State |
| 2026-06-24 | COLUMBIA GAS TRANS CORP/DONEGAL COMP STA | Pass | State |
| 2026-06-23 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/NANCY STEWART | Pass | State |
| 2026-06-17 | EQT PROD CO/MOJO COMPRESSOR UNIT | Pass | State |
| 2026-06-16 | GOLDEN EAGLE CONST CO/EIGHTY FOUR PLT | Pending | State |
| 2026-06-02 | EQM GATHERING OPCO LLC/PISCES COMP STA | Pass | State |
| 2026-05-04 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/REDD COMP STA | Pass | State |
| 2026-04-28 | MARKWEST LIBERTY MIDSTREAM/ CARPENTER COMP STA | Pass | State |
| 2026-04-22 | EQM GATHERING OPCO LLC/TWILIGHT COMP STA | Pass | State |
| 2026-04-16 | MARKWEST LIBERTY MIDST & RES/IMPERIAL CIBUS RANCH COMP STA | Pass | State |
| 2026-04-15 | MARKWEST LIBERTY MIDST & RES/IMPERIAL CIBUS RANCH COMP STA | Pass | State |
| 2026-04-09 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/SHAW COMP STA | Pass | State |
| 2026-04-01 | MARKWEST LIBERTY MIDSTREAM/DRYER BOOSTER COMP STA | Pass | State |
| 2026-04-01 | EQM GATHERING OPCO LLC/KRYPTONITE COMP STA | Pass | State |
| 2026-03-31 | MARKWEST LIBERTY MIDSTREAM/BRIGICH COMP STA | Pass | State |
| 2026-03-31 | EQM GATHERING OPCO LLC/KRYPTONITE COMP STA | Pass | State |
| 2026-03-27 | MARKWEST LIBERTY MIDSTREAM/SMITH COMP STA | Pass | State |
| 2026-03-24 | MARKWEST LIBERTY MIDSTREAM/BAKER COMP STA | Pass | State |
| 2026-03-20 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/HARMON CREEK GAS PLT — high-priority violation on file | Pass | State |
| 2026-03-17 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/FULTON BOOSTER STA — high-priority violation on file | Pass | State |
| 2026-03-17 | MARKWEST LIBERTY MIDST & RESOURCES/THREE BROTHERS COMP STA | Pass | State |
| 2026-02-26 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/LOWRY COMP STA | Pass | State |
| 2026-02-24 | MARKWEST LIBERTY MIDSTREAM/WELLING COMP STA | Pass | State |
| 2026-02-12 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/NANCY STEWART | Pass | State |
| 2026-02-10 | K PETROLEUM INC/HACKETT COMP STA — high-priority violation on file | Pass | State |
| 2026-02-09 | MARKWEST LIBERTY MIDSTREAM/TIMBERLAKE COMP STA | Pass | State |
| 2026-01-06 | PERRYMAN CO/TITANIUM CONVERSION FAC — 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.