EPA Air · stack tests by county and year
Air-emissions stack tests in Washington County, Pennsylvania, 2025
- 59Stack 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 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 Washington County facility page.
Washington County, Pennsylvania, 2025
Air-emissions stack tests in Washington County, other years
Air-emissions stack tests recorded in Washington County, Pennsylvania, 2025
| Date | Facility | Kind | Agency |
|---|---|---|---|
| 2025-12-17 | ETC NORTHEAST PIPELINE/REVOLUTION CRYO PLT | Pass | State |
| 2025-11-19 | MCC INTL/MILLER CENT CAST INC/MCDONALD PLT — high-priority violation on file | Pass | State |
| 2025-11-11 | COLUMBIA GAS TRANS LLC/REDD FARM COMP STA | Pass | State |
| 2025-11-05 | MARKWEST LIBERTY MIDST & RESOURCES/THREE BROTHERS COMP STA | Pass | State |
| 2025-11-04 | ROVER PIPELINE LLC/BULGER COMP STA | Pass | State |
| 2025-10-24 | DIVERSIFIED PROD LLC/NV 60 WELLPAD | Pass | State |
| 2025-10-17 | DIVERSIFIED PROD LLC/NV 34 WELLPAD — high-priority violation on file | Pass | State |
| 2025-10-16 | DIVERSIFIED PROD LLC/NINEVEH 58 WELL PAD — high-priority violation on file | Pass | State |
| 2025-10-15 | UGI GIBRALTAR GATHERING LLC/GIBRALTAR COMP STA | Pass | State |
| 2025-10-14 | EQM GATHERING OPCO LLC/MCINTOSH COMP STA | Pass | State |
| 2025-10-14 | EQM GATHERING OPCO LLC/MCINTOSH COMP STA | Pass | State |
| 2025-10-07 | JESSOP STEEL LLC/WASHINGTON PLT | Pass | State |
| 2025-10-07 | MARKWEST LIBERTY MIDSTREAM RES/DOWN HOME COMPRESSOR STATION | Pass | State |
| 2025-09-29 | NATL FUEL SUPPLY CORP/BUFFALO COMP STA | Pass | State |
| 2025-09-24 | EQM GATHERING OPCO LLC/BLUE MOON COMP STA | Pass | State |
| 2025-09-23 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/GODWIN COMP STA | Pass | State |
| 2025-09-22 | EQM GATHERING OPCO LLC/BLUE MOON COMP STA | Pass | State |
| 2025-09-08 | MARKWEST LIBERTY MID & RES / HOSKINS BOOSTER COMP STA | Pass | State |
| 2025-09-04 | EQT MIDSTREAM COMPANY LLC/DEEMSTON WICKS COMP STA | Pass | State |
| 2025-08-26 | EQM GATHERING OPCO LLC/STEELHEAD COMP STA | Pass | State |
| 2025-08-19 | CNX MIDSTREAM OPR CO LLC/MOR-44 COMP STA | Pass | State |
| 2025-08-14 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/LOWRY COMP STA | Pass | State |
| 2025-08-11 | CNX MIDSTREAM OPR CO LLC/NV-57 COMP STA | Pass | State |
| 2025-07-16 | ROVER PIPELINE LLC/BULGER COMP STA | Pass | State |
| 2025-07-16 | CNX MIDSTREAM OPR CO LLC/NV-57 COMP STA | Pass | State |
| 2025-07-15 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/JOHNSTON COMP STA | Pass | State |
| 2025-07-09 | EQM GATHERING OPCO LLC/BLUE MOON COMP STA | Pass | State |
| 2025-07-08 | EQM GATHERING OPCO LLC/BLUE MOON COMP STA | Pass | State |
| 2025-07-02 | FLEXSYS AMER LTD PAR/MONONGAHELA — high-priority violation on file | Pass | State |
| 2025-07-02 | COLUMBIA GAS TRANS CORP/DONEGAL COMP STA | Pass | State |
| 2025-06-23 | EQT PROD CO/MOJO COMPRESSOR UNIT | Pass | State |
| 2025-06-03 | JESSOP STEEL LLC/WASHINGTON PLT | Pass | State |
| 2025-06-03 | EQM GATHERING OPCO LLC/PISCES COMP STA | Pass | State |
| 2025-05-12 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/REDD COMP STA | Pass | State |
| 2025-05-07 | EQM GATHERING OPCO LLC/MAKO COMP STA | Pass | State |
| 2025-04-29 | MARKWEST LIBERTY MIDSTREAM/ CARPENTER COMP STA | Pass | State |
| 2025-04-23 | EQM GATHERING OPCO LLC/TWILIGHT COMP STA | Pass | State |
| 2025-04-10 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/SHAW COMP STA | Pass | State |
| 2025-04-02 | MARKWEST LIBERTY MIDSTREAM/DRYER BOOSTER COMP STA | Pass | State |
| 2025-04-02 | EQM GATHERING OPCO LLC/KRYPTONITE COMP STA | Pass | State |
| 2025-04-02 | EQM GATHERING OPCO LLC/KRYPTONITE COMP STA | Pass | State |
| 2025-04-01 | MARKWEST LIBERTY MIDSTREAM/BRIGICH COMP STA | Pass | State |
| 2025-04-01 | EQM GATHERING OPCO LLC/KRYPTONITE COMP STA | Pass | State |
| 2025-03-28 | MARKWEST LIBERTY MIDSTREAM/SMITH COMP STA | Pass | State |
| 2025-03-25 | MARKWEST LIBERTY MIDSTREAM/BAKER COMP STA | Pass | State |
| 2025-03-25 | EQT PROD CO/MOJO COMPRESSOR UNIT | Pass | State |
| 2025-03-19 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/FULTON BOOSTER STA — high-priority violation on file | Pass | State |
| 2025-02-27 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/LOWRY COMP STA | Pass | State |
| 2025-02-26 | MARKWEST LIBERTY MIDSTREAM/WELLING COMP STA | Pass | State |
| 2025-02-20 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/NANCY STEWART | Pass | State |
| 2025-02-19 | MARKWEST LIBERTY MIDST & RESOURCES/THREE BROTHERS COMP STA | Pass | State |
| 2025-02-19 | EQM GATHERING OPCO LLC/BLUE MOON COMP STA | Pass | State |
| 2025-02-10 | MARKWEST LIBERTY MIDSTREAM/TIMBERLAKE COMP STA | Pass | State |
| 2025-02-03 | K PETROLEUM INC/HACKETT COMP STA — high-priority violation on file | Fail | State |
| 2025-01-28 | ROVER PIPELINE LLC/BULGER COMP STA | Pass | State |
| 2025-01-27 | LOAN ASSET ISSUER LLC/WEST FINLEY 4 WELL PAD | Pass | State |
| 2025-01-17 | ENSINGER INC/WASHINGTON | Pass | State |
| 2025-01-10 | EQM GATHERING OPCO LLC/BLUE MOON COMP STA | Pass | State |
| 2025-01-07 | NATL FUEL SUPPLY CORP/BUFFALO COMP STA | Pass | State |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.