EPA Air · stack tests by state and year
Air-emissions stack tests in Pennsylvania, 2025
- 951Stack tests
A stack test measures what a source actually emits, at the stack, against the limit in its permit. Every stack test below was recorded against a source in Pennsylvania during 2025; one facility can appear more than once, because this is a record of what happened rather than a list of places.
Counties in Pennsylvania, 2025
- Susquehanna County 159
- Bradford County 63
- Washington County 59
- Lycoming County 51
- Greene County 47
- Tioga County 45
- Philadelphia County 41
- Butler County 30
- Westmoreland County 27
- Lancaster County 23
- Berks County 22
- Wyoming County 22
- Bucks County 21
- York County 19
- Mercer County 18
- Allegheny County 17
- Armstrong County 17
- Elk County 17
- Northampton County 15
- Montgomery County 15
- Delaware County 14
- Schuylkill County 13
- Luzerne County 12
- Potter County 11
- Clinton County 11
- Beaver County 10
- Fayette County 10
- Dauphin County 10
- Indiana County 9
- McKean County 9
- Centre County 9
- Chester County 8
- Cambria County 8
- Bedford County 8
- Venango County 7
- Jefferson County 6
- Columbia County 6
- Sullivan County 5
- Warren County 5
- Franklin County 5
- Clarion County 5
- Clearfield County 4
- Lawrence County 4
- Juniata County 3
- Montour County 3
- Carbon County 3
- Lehigh County 3
Pennsylvania, other years
Air-emissions stack tests recorded in Pennsylvania, 2025
| Date | Facility | Where | Kind | Agency |
|---|---|---|---|---|
| 2025-07-24 | APPALACHIA MIDSTREAM SVC LLC/AUBURN COMP STA | MESHOPPEN, Susquehanna, PA | Pass | State |
| 2025-07-24 | MARKWEST LIBERTY BLUESTONE LLC/ROYAL OAK COMP STA | EVANS CITY, Butler, PA | Pass | State |
| 2025-07-23 | AVERY DENNISON PERFORMANCE POLYMERS/MILL HALL PLT | MILL HALL, Clinton, PA | Pending | State |
| 2025-07-23 | HERCULES CEMENT CO LLC/STOCKERTOWN | STOCKERTOWN, Northampton, PA | Pass | State |
| 2025-07-23 | WILLIAMS FIELD SVC CO LLC/KANE ROAD COMP STA | MONTROSE, Susquehanna, PA | Pass | State |
| 2025-07-23 | HEP PENNSYLVANIA GATHERING LLC/LAUREL HILL COMP STA | TROUT RUN, Lycoming, PA | Pass | State |
| 2025-07-23 | UGI MORAINE EAST GATHERING LLC/RENICK COMP STA | WEST SUNBURY, Butler, PA | Pass | State |
| 2025-07-22 | US DEPT OF DEFENSE/LETTERKENNY ARMY DEPOT | CHAMBERSBURG, Franklin, PA | Pass | State |
| 2025-07-22 | SOUTHWESTERN ENERGY CO/RACINE 5H | NEW MILFORD, Susquehanna, PA | Pass | State |
| 2025-07-22 | UGI MORAINE EAST GATHERING LLC/RENICK COMP STA | WEST SUNBURY, Butler, PA | Pass | State |
| 2025-07-22 | EQM GATHERING OPCO LLC/PETTIT COMP STA | HOLBROOK, Greene, PA | Pass | State |
| 2025-07-22 | EQM GATHERING OPCO LLC/PETTIT COMP STA | HOLBROOK, Greene, PA | Pass | State |
| 2025-07-22 | NFG MIDSTREAM TROUT RUN LLC/TROUT RUN MTN COMP STA | TROUT RUN, Lycoming, PA | Pass | State |
| 2025-07-21 | DOMTAR PAPER CO/JOHNSONBURG MILL — high-priority violation on file | JOHNSONBURG, Elk, PA | Pass | State |
| 2025-07-21 | DOMTAR PAPER CO/JOHNSONBURG MILL — high-priority violation on file | JOHNSONBURG, Elk, PA | Pass | State |
| 2025-07-21 | CONSOL PA COAL CO LLC/BAILEY PREP PLT — high-priority violation on file | WEST FINLEY, Greene, PA | Pass | State |
| 2025-07-21 | WILLIAMS FIELD SVC CO LLC/SNAKE CREEK COMP STA | CLARKS SUMMIT, Susquehanna, PA | Pass | State |
| 2025-07-21 | NFG MIDSTREAM COVINGTON LLC/LAWTON COMP STA | WELLSBORO, Tioga, PA | Pass | State |
| 2025-07-21 | CABOT OIL & GAS CORP/BISHOP, B PAD 1 | SPRINGVILLE, Susquehanna, PA | Pass | State |
| 2025-07-21 | INFINITY NATURAL RESOURCES SOUTH BEND COMP STA | SOUTH BEND TWP, Armstrong, PA | Pass | State |
| 2025-07-18 | PA STATE UNIV/MILTON S HERSHEY MED CTR | HERSHEY, Dauphin, PA | Pass | State |
| 2025-07-17 | EASTERN GAS TRANS & STORAGE INC/LINCOLN HEIGHTS | LINCOLN HEIGHTS, Westmoreland, PA | Pass | State |
| 2025-07-17 | KEYSTONE PORTLAND CEMENT/EAST ALLEN — high-priority violation on file | BATH, Northampton, PA | Pass | State |
| 2025-07-17 | HEP PENNSYLVANIA GATHERING LLC/WHITE CPF 1 COMP STA | STEVENSVILLE, Bradford, PA | Pass | State |
| 2025-07-17 | ENERGY CTR LANCASTER LLC/LANCASTER — high-priority violation on file | LANCASTER, Lancaster, PA | Pass | State |
| 2025-07-16 | HEIDELBERG MATERIALS US CEMENT LLC/EVANSVILLE CEMENT PLT & Q — high-priority violation on file | FLEETWOOD, Berks, PA | Pass | State |
| 2025-07-16 | ROVER PIPELINE LLC/BULGER COMP STA | BULGER, Washington, PA | Pass | State |
| 2025-07-16 | CNX MIDSTREAM OPR CO LLC/NV-57 COMP STA | PROSPERITY, Washington, PA | Pass | State |
| 2025-07-16 | STARZEC, E. PAD 1 | MONTROSE, Susquehanna, PA | Pass | State |
| 2025-07-16 | GEIGER, K. PAD 1 | MONTROSE, Susquehanna, PA | Pass | State |
| 2025-07-15 | TEXAS EASTERN TRANS LP/UNIONTOWN STA — high-priority violation on file | LEMONT FURNACE, Fayette, PA | Pass | State |
| 2025-07-15 | POST BRANDS PET CARE LLC/BLOOMSBURG PLT | BLOOMSBURG, Columbia, PA | Pass | State |
| 2025-07-15 | ALLAN MYERS LP/COATESVILLE ASPHALT PLT | COATESVILLE, Chester, PA | Pass | State |
| 2025-07-15 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/JOHNSTON COMP STA | CANONSBURG, Washington, PA | Pass | State |
| 2025-07-15 | CNX MIDSTREAM OPR CO LLC/MCQUAY COMP STA | CENTER TOWNSHIP, Greene, PA | Pass | State |
| 2025-07-15 | EQUITRANS LP/REDHOOK COMPRESSOR STATION | WAYNESBURG, Greene, PA | Pass | State |
| 2025-07-15 | CHESAPEAKE APPALACHIA LLC/AMCOR WELLPAD | MESHOPPEN, Wyoming, PA | Pass | State |
| 2025-07-12 | MOXIE FREEDOM GENERATION PLANT/SALEM TWP | BERWICK, Luzerne, PA | Pass | State |
| 2025-07-10 | RAUSCH CREEK GENERATION LLC/FRAILEY TWP — high-priority violation on file | TREMONT, Schuylkill, PA | Pass | State |
| 2025-07-10 | GLENN O HAWBAKER INC/DUBOIS PLT 4 | DUBOIS, Clearfield, PA | Pass | State |
| 2025-07-10 | EQM GATHERING OPCO LLC/COLE FARM COMPRESSOR STATION | HOLBROOK, Greene, PA | Pass | State |
| 2025-07-10 | NATIONAL FUEL GAS SUPPLY CORP/TAMARACK COMP STA | CROSS FORK, Clinton, PA | Pass | State |
| 2025-07-10 | NATIONAL FUEL GAS SUPPLY CORP/TAMARACK COMP STA | CROSS FORK, Clinton, PA | Pass | State |
| 2025-07-09 | RAUSCH CREEK GENERATION LLC/FRAILEY TWP — high-priority violation on file | TREMONT, Schuylkill, PA | Pass | State |
| 2025-07-09 | GLENN O HAWBAKER INC/NAGINEY | MILROY, Mifflin, PA | Pass | State |
| 2025-07-09 | COLUMBIA GAS TRANS CORP/CGT DELMONT COMP STA | DELMONT, Westmoreland, PA | Pass | State |
| 2025-07-09 | SEWARD GENERATING STATION/SEWARD | NEW FLORENCE, Indiana, PA | Pass | State |
| 2025-07-09 | HEP PA GATHERING LLC/GREENZWEIG COMP STA | WYALUSING, Bradford, PA | Pass | State |
| 2025-07-09 | WILLIAMS FIELD SVC CO LLC/CENTRAL COMP STA | MONTROSE, Susquehanna, PA | Pass | State |
| 2025-07-09 | EQM GATHERING OPCO LLC/BLUE MOON COMP STA | DAISYTOWN, Washington, PA | Pass | State |
| 2025-07-09 | EARTHCARE LLC/BETHEL | BETHEL, Berks, PA | Pass | State |
| 2025-07-08 | EASTERN GAS TRANS & STORAGE INC/SABINSVILLE STA | WESTFIELD, Tioga, PA | Pass | State |
| 2025-07-08 | TEXAS EASTERN TRANS LP/GRANTVILLE | GRANTVILLE, Dauphin, PA | Pass | State |
| 2025-07-08 | HEP PENNSYLVANIA GATHERING LLC/CLARK CPF 1 COMP STA | WYSOX, Bradford, PA | Pass | State |
| 2025-07-08 | PINE RUN MIDSTREAM LLC/BASS COMP STA | SAXONBURG, Butler, PA | Pass | State |
| 2025-07-08 | EQM GATHERING OPCO LLC/BLUE MOON COMP STA | DAISYTOWN, Washington, PA | Pass | State |
| 2025-07-08 | EM RESOURCES LLC/MONTOUR PLT | DANVILLE, Montour, PA | Pass | State |
| 2025-07-07 | WILLIAMS FIELD SVC CO LLC/FRASER COMP STA | MONTROSE, Susquehanna, PA | Pass | State |
| 2025-07-07 | LONGHORN PAD C/ELK | WEEDVILLE, Elk, PA | Pass | State |
| 2025-07-03 | COLUMBIA GAS TRANS LLC/IOWA COMP STA | BROOKVILLE, Jefferson, PA | Pass | State |
| 2025-07-02 | FLEXSYS AMER LTD PAR/MONONGAHELA — high-priority violation on file | MONONGAHELA, Washington, PA | Pass | State |
| 2025-07-02 | COLUMBIA GAS TRANS CORP/DONEGAL COMP STA | WEST ALEXANDER, Washington, PA | Pass | State |
| 2025-07-02 | COLUMBIA GAS TRANS LLC/ARTEMAS COMP STA | ARTEMAS, Bedford, PA | Pass | State |
| 2025-07-02 | DELAWARE CNTY REG WA/DELCORA WESTERN REG TRMT PLT | CHESTER, Delaware, PA | Pass | State |
| 2025-07-02 | APPALACHIA MIDSTREAM SVC LLC/GRANVILLE STA 2 | GRANVILLE SUMMIT, Bradford, PA | Pass | State |
| 2025-07-02 | SOUTHWESTERN ENERGY CO/KOZIOL 5H-6H | NEW MILFORD, Susquehanna, PA | Pass | State |
| 2025-07-02 | RANGE RESOURCES APPALACHIA/LAUREL HILL D 17531 PAD | TROUT RUN, Lycoming, PA | Pass | State |
| 2025-07-01 | COLUMBIA GAS TRANS LLC/ARTEMAS COMP STA | ARTEMAS, Bedford, PA | Pass | State |
| 2025-07-01 | COLUMBIA GAS TRANS LLC/ARTEMAS COMP STA | ARTEMAS, Bedford, PA | Pass | State |
| 2025-07-01 | COLUMBIA GAS TRANS LLC/ARTEMAS COMP STA | ARTEMAS, Bedford, PA | Pass | State |
| 2025-07-01 | DELAWARE CNTY REG WA/DELCORA WESTERN REG TRMT PLT | CHESTER, Delaware, PA | Pass | State |
| 2025-07-01 | CLINTON CNTY SOLID W/WAYNE TWP LDFL | MC ELHATTAN, Clinton, PA | Pass | State |
| 2025-07-01 | CLINTON CNTY SOLID W/WAYNE TWP LDFL | MC ELHATTAN, Clinton, PA | Pass | State |
| 2025-07-01 | MTN GATHERING/ADAMS COMP STA | VANDERBILT, Fayette, PA | Pass | State |
| 2025-07-01 | HEIDELBERG MTLS NORTHEAST PA / GLEN MILLS HMA PLT — high-priority violation on file | GLEN MILLS, Delaware, PA | Pass | State |
| 2025-07-01 | APPALACHIA MIDSTREAM SVC LLC/RATTLESNAKE HILL COMP STA | AUBURN TOWNSHIP, Susquehanna, PA | Pass | State |
| 2025-07-01 | EQT ARO LLC/LYCOMING H&FC COMP STA — high-priority violation on file | TROUT RUN, Lycoming, PA | Pass | State |
| 2025-06-30 | APPALACHIA MIDSTREAM SVC LLC/AUBURN COMP STA | MESHOPPEN, Susquehanna, PA | Pass | State |
| 2025-06-27 | OPTINOVA VALLEY FORGE/PLYMOUTH MEETING | PLYMOUTH MEETING, Montgomery, PA | Pass | State |
| 2025-06-27 | CORAOPOLIS TERMINALS DE LLC | CORAOPOLIS, Allegheny, PA | Pass | Local |
| 2025-06-26 | EQUITRANS LP/TRUITTSBURG STA | FAIRMOUNT CITY, Clarion, PA | Pass | State |
| 2025-06-26 | ARDAGH GLASS INC/PORT ALLEGANY PLT — high-priority violation on file | PORT ALLEGANY, McKean, PA | Pass | State |
| 2025-06-26 | WASTE MGMT PA/TULLYTOWN RES REC FAC | TULLYTOWN, Bucks, PA | Pass | State |
| 2025-06-26 | EASTERN GAS TRANS & STORAG INC/ROCK SPRINGS COMP STA | DELMONT, Westmoreland, PA | Pass | State |
| 2025-06-26 | UGI AUBURN GATHERING LLC/ MANNING COMPRESSOR LNG STA | MESHOPPEN, Wyoming, PA | Pass | State |
| 2025-06-26 | HUSTON, J. PAD 1 | KINGSLEY, Susquehanna, PA | Pass | State |
| 2025-06-26 | HAWK, J. PAD 1 | MESHOPPEN, Susquehanna, PA | Pass | State |
| 2025-06-26 | USS/CLAIRTON WORKS — high-priority violation on file | CLAIRTON, Allegheny, PA | Pass | Local |
| 2025-06-25 | TEXAS EASTERN TRANS LP/SHERMANS DALE | SHERMANS DALE, Perry, PA | Pass | State |
| 2025-06-25 | CREPS UNITED PUBLICATIONS/WINDY RIDGE IND PARK | INDIANA, Indiana, PA | Pass | State |
| 2025-06-25 | CREPS UNITED PUBLICATIONS/WINDY RIDGE IND PARK | INDIANA, Indiana, PA | Pass | State |
| 2025-06-25 | EQM GATHERING OPCO LLC/EUROPA COMP STA | CENTER, Greene, PA | Pass | State |
| 2025-06-25 | UGI AUBURN GATHERING LLC/ANDERSON COMP STA | NEW RINGGOLD, Susquehanna, PA | Pass | State |
| 2025-06-25 | EXPAND OPERATING LLC/SIVERS BRA PAD | LACEYVILLE, Bradford, PA | Pass | State |
| 2025-06-25 | LARUE, C PAD 2 — high-priority violation on file | MONTROSE, Susquehanna, PA | Pass | State |
| 2025-06-25 | COP TRACT 596 PAD A | ROARING BRANCH, Tioga, PA | Pass | State |
| 2025-06-25 | POWERS, M. PAD 1 | MESHOPPEN, Susquehanna, PA | Pass | State |
| 2025-06-25 | CORAOPOLIS TERMINALS DE LLC | CORAOPOLIS, Allegheny, PA | Pass | Local |
| 2025-06-24 | TEXAS EASTERN TRANS LP/MARIETTA | MARIETTA, Lancaster, PA | Pass | State |
| 2025-06-24 | UGI AUBURN GATHERING LLC/AUBURN COMP STA | AUBURN, Susquehanna, PA | Pass | State |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.