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 |
|---|---|---|---|---|
| 2025-10-03 | INNOVATION 411/UPPER MERION — high-priority violation on file | KING OF PRUSSIA, Montgomery, PA | Pass | State |
| 2025-10-03 | COTERRA ENERGY INC/HAYNES W PAD 1 | NEW MILFORD, Susquehanna, PA | Pass | State |
| 2025-10-02 | PA GEN ENERGY CO LLC/COP TRACT 293 COMP STA | WATERVILLE, Lycoming, PA | Pass | State |
| 2025-10-02 | AUSTIN, E. PAD 1 | HOP BOTTOM, Susquehanna, PA | Pass | State |
| 2025-10-01 | MERSEN USA/ST MARYS | SAINT MARYS, Elk, PA | Pass | State |
| 2025-10-01 | NFG MIDSTREAM COVINGTON LLC/NETTERMAN COMP STA | WELLSBORO, Tioga, PA | Pass | State |
| 2025-10-01 | EQM GATHERING OPCO LLC/SNAPPING TURTLE COMP STA | WIND RIDGE, Greene, PA | Pass | State |
| 2025-10-01 | CABOT OIL & GAS CORP/KROPA, T. PAD 1 | SPRINGVILLE, Susquehanna, PA | Pass | State |
| 2025-10-01 | COTERRA ENERGY INC/ADAMS J PAD 1 | KINGSLEY, Susquehanna, PA | Pass | State |
| 2025-10-01 | CONSTELLATION GENERATION CO/DELAWARE STA | PHILADELPHIA, Philadelphia, PA | Pass | Local |
| 2025-10-01 | CONSTELLATION GENERATION CO/DELAWARE STA | PHILADELPHIA, Philadelphia, PA | Pass | Local |
| 2025-09-30 | LATROBE SPECIALTY METALS/ A CARPENTER CO | LATROBE, Westmoreland, PA | Pass | State |
| 2025-09-30 | NATL FUEL GAS SUPPLY/ELLISBURG STA | ELLISBURG, Potter, PA | Pass | State |
| 2025-09-30 | MERSEN USA/ST MARYS | SAINT MARYS, Elk, PA | Pass | State |
| 2025-09-30 | LEWIS RUN GAS PLANT LLC/LEWIS RUN GAS PLANT | BRADFORD, McKean, PA | Pass | State |
| 2025-09-30 | BKV OPR LLC/P & G WAREHOUSE PAD | MESHOPPEN, Wyoming, PA | Pass | State |
| 2025-09-30 | EQM GATHERING OPCO LLC/SNAPPING TURTLE COMP STA | WIND RIDGE, Greene, PA | Pass | State |
| 2025-09-30 | EXPAND OPERATING LLC/MARIS SUS PAD | MESHOPPEN, Susquehanna, PA | Pass | State |
| 2025-09-29 | RAUSCH CREEK GENERATION LLC/FRAILEY TWP — high-priority violation on file | TREMONT, Schuylkill, PA | Pass | State |
| 2025-09-29 | NATL FUEL SUPPLY CORP/BUFFALO COMP STA | WASHINGTON, Washington, PA | Pass | State |
| 2025-09-26 | GREYLOCK MIDSTREAM LLC/CUMBERLAND HENDERSON COMP STA | CARMICHAELS, Greene, PA | Pass | State |
| 2025-09-25 | VITRO FLAT GLASS LLC/CARLISLE — high-priority violation on file | CARLISLE, Cumberland, PA | Pass | State |
| 2025-09-25 | ERIE SEWER AUTHORITY/ERIE WWTP — high-priority violation on file | ERIE, Erie, PA | Pass | State |
| 2025-09-25 | PA GEN ENERGY CO LLC/POTATO CREEK 2H COMP STA | SMETHPORT, McKean, PA | Pass | State |
| 2025-09-25 | EXPAND OPERATING LLC/HOOKER SUS PAD | MESHOPPEN, Susquehanna, PA | Pass | State |
| 2025-09-24 | VITRO MEADVILLE FLAT GLASS MEADVILLE PLT/CRAWFORD | COCHRANTON, Crawford, PA | Pass | State |
| 2025-09-24 | ARCONIC US LLC/LANCASTER — high-priority violation on file | LANCASTER, Lancaster, PA | Pass | State |
| 2025-09-24 | EASTERN GAS TRANS & STORAGE INC/FINNEFROCK STA | RENOVO, Clinton, PA | Pass | State |
| 2025-09-24 | REWORLD DELAWARE VALLEY LP/DELAWARE VALLEY RES REC — high-priority violation on file | CHESTER, Delaware, PA | Pass | State |
| 2025-09-24 | EQM GATHERING OPCO LLC/BLUE MOON COMP STA | DAISYTOWN, Washington, PA | Pass | State |
| 2025-09-24 | HOUSENICK, J. PAD 1 | MONTROSE, Susquehanna, PA | Pass | State |
| 2025-09-24 | WARRINER, R. PAD 2 | MONTROSE, Susquehanna, PA | Pass | State |
| 2025-09-23 | INTL WAXES INC/FARMERS VALLEY | SMETHPORT, McKean, PA | Pass | State |
| 2025-09-23 | PECORA CORP/PECORA | HARLEYSVILLE, Montgomery, PA | Pass | State |
| 2025-09-23 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/GODWIN COMP STA | WASHINGTON, Washington, PA | Pass | State |
| 2025-09-23 | APPALACHIA MIDSTREAM SVC LLC/RED FOX CDP | FOX, Sullivan, PA | Pass | State |
| 2025-09-23 | EXPAND OPERATING LLC/FERRARO WELL PAD | NEW ALBANY, Bradford, PA | Pass | State |
| 2025-09-23 | EXPAND OPERATING LLC/ RU-13 TONYA EAST PAD | NEW MILFORD, Susquehanna, PA | Pass | State |
| 2025-09-22 | EQM GATHERING OPCO LLC/BLUE MOON COMP STA | DAISYTOWN, Washington, PA | Pass | State |
| 2025-09-20 | CPV FAIRVIEW LLC/FAIRVIEW ENERGY CTR — high-priority violation on file | JOHNSTOWN, Cambria, PA | Pass | State |
| 2025-09-19 | SCHUYLKILL ENERGY RES/ST NICHOLAS COGEN — high-priority violation on file | SHENANDOAH, Schuylkill, PA | Pass | State |
| 2025-09-19 | DIVERSIFIED MIDSTREAM LLC/TIOGA COMP STA | WELLSBORO, Tioga, PA | Pass | State |
| 2025-09-18 | EUREKA STONE QUARRY/CHALFONT QUARRY & ASPHALT PLT | CHALFONT, Bucks, PA | Pass | State |
| 2025-09-18 | ABINGTON MEM HOSP/ABINGTON | ABINGTON, Montgomery, PA | Pass | State |
| 2025-09-18 | MARKWEST LIBERTY BLUESTONE LLC/BLUESTONE GAS PROC PLT | EVANS CITY, Butler, PA | Pass | State |
| 2025-09-17 | LAUREL MTN MIDSTREAM OPR LLC/SPRINGHILL COMP STA | LAKE LYNN, Fayette, PA | Pass | State |
| 2025-09-17 | MARKWEST LIBERTY BLUESTONE LLC/SARSEN GAS PROC PLT | EVANS CITY, Butler, PA | Pass | State |
| 2025-09-17 | REGENCY MARCELLUS GAS GATHERING LLC/ HIRKEY COMP STA | TUNKHANNOCK, Wyoming, PA | Pass | State |
| 2025-09-17 | REGENCY MARCELLUS GAS GATHERING LLC/QUAKER STATE RD COMP STA | MONTOURSVILLE, Lycoming, PA | Pass | State |
| 2025-09-16 | ADHESIVES RESEARCH INC/GLEN ROCK — high-priority violation on file | GLEN ROCK, York, PA | Pass | State |
| 2025-09-16 | PEOPLES NATURAL GAS CO LLC/LIMESTONE COMP STA | SUMMERVILLE, Clarion, PA | Pass | State |
| 2025-09-16 | PA GEN ENERGY CO LLC/POTATO CREEK 1H COMP STA | CROSBY, McKean, PA | Pass | State |
| 2025-09-16 | SUSQUEHANNA GATHERING CO 1 LLC/CDP 3 | NEW MILFORD, Susquehanna, PA | Pass | State |
| 2025-09-16 | ETC NORTHEAST PIPELINE/GALAXY COMP STA | PARKER, Butler, PA | Pass | State |
| 2025-09-12 | ARCONIC US LLC/LANCASTER — high-priority violation on file | LANCASTER, Lancaster, PA | Pass | State |
| 2025-09-12 | PUROLITE INC/MFG CHEM — high-priority violation on file | PHILADELPHIA, Philadelphia, PA | Pending | Local |
| 2025-09-12 | PUROLITE INC/MFG CHEM — high-priority violation on file | PHILADELPHIA, Philadelphia, PA | Fail | Local |
| 2025-09-11 | NLMK PENNSYLVANIA LLC/FARRELL PLT — high-priority violation on file | FARRELL, Mercer, PA | Pass | State |
| 2025-09-11 | ENERGY TRANSFER MKT & TERM LP/NORTHUMBERLAND TERM | NORTHUMBERLAND, Northumberland, PA | Pass | State |
| 2025-09-11 | WILLIAMS FIELD SVC CO LLC/LATHROP COMP STA | SPRINGVILLE, Susquehanna, PA | Pass | State |
| 2025-09-11 | REGENCY MARCELLUS GAS GATHERING LLC/ AUBURN STA | MESHOPPEN, Susquehanna, PA | Pass | State |
| 2025-09-11 | PUROLITE INC/MFG CHEM — high-priority violation on file | PHILADELPHIA, Philadelphia, PA | Pass | Local |
| 2025-09-10 | CNX MIDSTREAM OPR CO LLC /MORRIS DEHY STATION | GRAYSVILLE, Greene, PA | Pass | State |
| 2025-09-10 | REV LNG SSL BC LLC/NICHE LNG LLC - TOWANDA FAC | WYALUSING, Bradford, PA | Pass | State |
| 2025-09-09 | NLMK PENNSYLVANIA LLC/FARRELL PLT — high-priority violation on file | FARRELL, Mercer, PA | Pass | State |
| 2025-09-09 | WILLIAMS FIELD SVC CO LLC/SHASKAS COMP STA | MONTROSE, Susquehanna, PA | Pass | State |
| 2025-09-09 | NFG MIDSTREAM COVINGTON LLC/CLARK COMP STA | MAINESBURG, Tioga, PA | Pass | State |
| 2025-09-09 | EXPAND OPERATING LLC/NOWICKI PAD NR25 | SUSQUEHANNA, Susquehanna, PA | Pass | State |
| 2025-09-08 | NLMK PENNSYLVANIA LLC/FARRELL PLT — high-priority violation on file | FARRELL, Mercer, PA | Pending | State |
| 2025-09-08 | WESTMORELAND SANITARY LDFL LLC/BELLE VERNON — high-priority violation on file | BELLE VERNON, Westmoreland, PA | Pass | State |
| 2025-09-08 | MARKWEST LIBERTY MID & RES / HOSKINS BOOSTER COMP STA | CLAYSVILLE, Washington, PA | Pass | State |
| 2025-09-08 | HEP PENNSYLVANIA GATHERING LLC/WHITE CPF 1 COMP STA | STEVENSVILLE, Bradford, PA | Pass | State |
| 2025-09-05 | HEP PENNSYLVANIA GATHERING LLC/WHITE CPF 1 COMP STA | STEVENSVILLE, Bradford, PA | Pass | State |
| 2025-09-05 | REGENCY MARCELLUS GAS GATHERING LLC/TAYLOR COMP STA | CANTON, Bradford, PA | Pass | State |
| 2025-09-05 | EXPAND OPERATING LLC/ROSIEMAR SUS PAD | MESHOPPEN, Susquehanna, PA | Pass | State |
| 2025-09-04 | BEFESA ZINC US INC./PALMERTON — high-priority violation on file | PALMERTON, Carbon, PA | Pass | State |
| 2025-09-04 | EQT MIDSTREAM COMPANY LLC/DEEMSTON WICKS COMP STA | FREDERICKTOWN, Washington, PA | Pass | State |
| 2025-09-04 | EQM GATHERING OPCO LLC/CYGRYMUS COMP STA | NEW FREEPORT, Greene, PA | Pass | State |
| 2025-09-04 | USS/CLAIRTON WORKS — high-priority violation on file | CLAIRTON, Allegheny, PA | Pass | Local |
| 2025-09-03 | EBENSBURG POWER CO/EBENSBURG COGENERATION PLT | EBENSBURG, Cambria, PA | Pass | State |
| 2025-09-03 | ARMSTRONG CEMENT & SUPPLY/WINFIELD — high-priority violation on file | CABOT, Butler, PA | Pass | State |
| 2025-09-03 | WESTMORELAND SANITARY LDFL LLC/BELLE VERNON — high-priority violation on file | BELLE VERNON, Westmoreland, PA | Fail | State |
| 2025-09-03 | JOHNSON MATTHEY INC/SMITHFIELD — high-priority violation on file | SMITHFIELD, Fayette, PA | Pass | State |
| 2025-09-03 | NFG MIDSTREAM COVINGTON LLC/KRAUSE COMP STA | MAINESBURG, Tioga, PA | Pass | State |
| 2025-09-03 | MARKWEST LIBERTY BLUESTONE LLC/BLUESTONE GAS PROC PLT | EVANS CITY, Butler, PA | Pass | State |
| 2025-09-03 | HEP PENNSYLVANIA GATHERING LLC/CLARK CPF 1 COMP STA | WYSOX, Bradford, PA | Pass | State |
| 2025-09-03 | PAYNE, D. PAD 1 | NEW MILFORD, Susquehanna, PA | Pass | State |
| 2025-09-02 | EBENSBURG POWER CO/EBENSBURG COGENERATION PLT | EBENSBURG, Cambria, PA | Pass | State |
| 2025-09-02 | WRIGHT, W. PAD 1 | MONTROSE, Susquehanna, PA | Pass | State |
| 2025-09-02 | VANDERMARK, R. PAD 1 | MONTROSE, Susquehanna, PA | Pass | State |
| 2025-08-29 | WALTER R EARLE ASPHALT PLT/MORRISVILLE — high-priority violation on file | MORRISVILLE, Bucks, PA | Pending | State |
| 2025-08-29 | MARKWEST LIBERTY BLUESTONE LLC/TRILLITH COMP STA | HARMONY, Butler, PA | Pass | State |
| 2025-08-29 | EXPAND OPERATING LLC/KAUFMANN WELL PAD | NEW ALBANY, Bradford, PA | Pass | State |
| 2025-08-28 | COLUMBIA GAS TRANS LLC/EAGLE | CHESTER SPRINGS, Chester, PA | Pass | State |
| 2025-08-28 | SONNEBORN INC/PETROLIA PLT | PETROLIA, Butler, PA | Pass | State |
| 2025-08-28 | RAUSCH CREEK GENERATION LLC/FRAILEY TWP — high-priority violation on file | TREMONT, Schuylkill, PA | Pass | State |
| 2025-08-28 | ESAB WELDING & CUTTING PROD/HANOVER | HANOVER, York, PA | Pass | State |
| 2025-08-28 | REGENCY MARCELLUS GAS GATHERING LLC/BOBST MOUNTAIN COMP STA | COGAN STA, Lycoming, PA | Pass | State |
| 2025-08-28 | ETC NORTHEAST FLD SVC LLC/PIKE COMP STA | ROCHESTER, Beaver, PA | Pass | State |
| 2025-08-27 | NEW ENTERPRISE STONE & LIME CO INC/WESCOSVILLE PLT | ALLENTOWN, Lehigh, PA | Pass | State |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.