EPA Air · stack tests by state and year

Air-emissions stack tests in Pennsylvania, 2026

501Stack 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 2026; one facility can appear more than once, because this is a record of what happened rather than a list of places.

Counties in Pennsylvania, 2026

Pennsylvania, other years

Air-emissions stack tests recorded in Pennsylvania, 2026

Date	Facility	Where	Kind	Agency
2026-03-27	MARKWEST LIBERTY MIDSTREAM/SMITH COMP STA	BURGETTSTOWN, Washington, PA	Pass	State
2026-03-27	NFG MIDSTREAM CLERMONT LLC/RICH VALLEY COMP STA	EMPORIUM, Cameron, PA	Pass	State
2026-03-26	WILLIAMS FIELD SVC CO LLC/TEEL COMP STA	SPRINGVILLE, Susquehanna, PA	Pass	State
2026-03-26	EQM GATHERING OPCO LLC/COLE FARM COMPRESSOR STATION	HOLBROOK, Greene, PA	Pass	State
2026-03-25	EASTERN GAS TRANS & STORAGE INC/SOUTH BEND COMP STA	SHELOCTA, Armstrong, PA	Pass	State
2026-03-25	ARMSTRONG CEMENT & SUPPLY/WINFIELD — high-priority violation on file	CABOT, Butler, PA	Pass	State
2026-03-25	POWERS, N. PAD 1	MONTROSE, Susquehanna, PA	Pass	State
2026-03-25	WALDENBERGER, P. PAD 1	SPRINGVILLE, Susquehanna, PA	Pass	State
2026-03-24	TRANSCONTINENTAL GAS/BEAR CREEK STA 515	BEAR CREEK, Luzerne, PA	Pass	State
2026-03-24	MARKWEST LIBERTY MIDSTREAM/BAKER COMP STA	WASHINGTON, Washington, PA	Pass	State
2026-03-23	PINE RUN MIDSTREAM LLC/TROUT COMP STA	WORTHINGTON, Armstrong, PA	Pass	State
2026-03-23	VICINITY ENERGY EDISON/PHILA — high-priority violation on file	PHILADELPHIA, Philadelphia, PA	Pending	Local
2026-03-20	HILCORP ENERGY CO/PULASKI WHITING CTL FAC — high-priority violation on file	EDINBURG, Lawrence, PA	Pass	State
2026-03-20	MARKWEST LIBERTY MIDSTREAM & RESOURCES/HARMON CREEK GAS PLT — high-priority violation on file	BULGER, Washington, PA	Pass	State
2026-03-19	PROCTER & GAMBLE PAPER PROD CO/MEHOOPANY	MEHOOPANY, Wyoming, PA	Pass	State
2026-03-19	GELEST INC/FALLS TWP — high-priority violation on file	MORRISVILLE, Bucks, PA	Pass	State
2026-03-19	GELEST INC/FALLS TWP — high-priority violation on file	MORRISVILLE, Bucks, PA	Fail	State
2026-03-19	UGI PONDEROSA LLC/STURGIS PAD B COMP STA	LOCK HAVEN, Clinton, PA	Pass	State
2026-03-18	NORTHAMPTON GEN CO/NORTHAMPTON	NORTHAMPTON, Northampton, PA	Pass	State
2026-03-18	UNITED REFINING CO/WARREN PLT	WARREN, Warren, PA	Pass	State
2026-03-18	LAUREL MTN MIDSTREAM OPR LLC/CANTARAL COMP STA	WAYNESBURG, Greene, PA	Pass	State
2026-03-18	NFG MIDSTREAM TROUT RUN LLC/BODINE COMP STA	TROUT RUN, Lycoming, PA	Pass	State
2026-03-17	MARKWEST LIBERTY MIDSTREAM & RESOURCES/FULTON BOOSTER STA — high-priority violation on file	HICKORY, Washington, PA	Pass	State
2026-03-17	MARKWEST LIBERTY MIDST & RESOURCES/THREE BROTHERS COMP STA	BURGETTSTOWN, Washington, PA	Pass	State
2026-03-17	TEMPLE UNIV/ MAIN CAMPUS — high-priority violation on file	PHILADELPHIA, Philadelphia, PA	Fail	Local
2026-03-16	NFG MIDSTREAM COVINGTON LLC/DCNR TRACT 595	ARNOT, Tioga, PA	Pass	State
2026-03-16	TEMPLE UNIV/ MAIN CAMPUS — high-priority violation on file	PHILADELPHIA, Philadelphia, PA	Pass	Local
2026-03-13	KEYSTONE CONEMAUGH PROJ LLC/KEYSTONE STATION	SHELOCTA, Armstrong, PA	Pass	State
2026-03-13	WILLIAMS FIELD SVC CO LLC/CHURCH COMP STA	SPRINGVILLE, Susquehanna, PA	Pass	State
2026-03-13	SNYDER BROS INC/WHITE COMP STA	KITTANNING, Armstrong, PA	Pass	State
2026-03-12	COLUMBIA GAS TRANS CORP/GREENCASTLE	GREENCASTLE, Franklin, PA	Pass	State
2026-03-12	MARKWEST LIBERTY BLUESTONE LLC/BLUESTONE GAS PROC PLT	EVANS CITY, Butler, PA	Pass	State
2026-03-12	WILLIAMS FIELD SVC CO LLC/SHIELDS COMP STA	SPRINGVILLE, Susquehanna, PA	Pass	State
2026-03-11	LEHIGH WHITE CEMENT CO LLC/YORK	YORK, York, PA	Pass	State
2026-03-11	WILLIAMS FIELD SVC CO LLC/WILCOX COMP STA	TUNKHANNOCK, Wyoming, PA	Pass	State
2026-03-11	EXPAND OPERATING LLC/BLYE WELL PAD	MONTROSE, Susquehanna, PA	Pass	State
2026-03-11	CLEAN ENERGY EXPL & PROD LLC/WHISPERING PINES WELL PAD	WELLSBORO, Tioga, PA	Pass	State
2026-03-10	EASTERN GAS TRANS & STORAGE INC/BOOM STA	LAWRENCEVILLE, Tioga, PA	Pass	State
2026-03-10	RAUSCH CREEK GENERATION LLC/FRAILEY TWP — high-priority violation on file	TREMONT, Schuylkill, PA	Pass	State
2026-03-10	EQT ARO LLC/COP TRACT 685 COMP STA — high-priority violation on file	JERSEY SHORE, Lycoming, PA	Pass	State
2026-03-10	EQM GATHERING OPCO LLC/HALO COMP STA	SYCAMORE, Greene, PA	Pass	State
2026-03-10	EXPAND OPER LLC/TI-46-BLISS WELL PAD	LIBERTY, Tioga, PA	Pass	State
2026-03-10	BOLLES COMPRESSOR STATION/JESSUP TWP	MONTROSE, Susquehanna, PA	Pass	State
2026-03-09	DIVERSIFIED PROD LLC/BELL POINT COMP STA	APOLLO, Westmoreland, PA	Pass	State
2026-03-09	EQT ARO LLC/TRACT 285 COMP STA	NORTH BEND, Clinton, PA	Pass	State
2026-03-05	EQT ARO LLC/TRACT 289 COMP STA — high-priority violation on file	JERSEY SHORE, Lycoming, PA	Pass	State
2026-03-05	SNYDER BROS INC/AMBROSE COMP STA	ADRIAN, Armstrong, PA	Pass	State
2026-03-04	EASTERN GAS TRANS & STORAGE/ROCHESTER MILLS	ROCHESTER MILLS, Indiana, PA	Pass	State
2026-03-04	BERRYVILLE GRAPHICS/FAIRFIELD	FAIRFIELD, Adams, PA	Pass	State
2026-03-04	CLARION BOARDS/CLARION PLT	SHIPPENVILLE, Clarion, PA	Pass	State
2026-03-04	NEXTERA RENEWABLE FUELS LLC/FREY FARM CRESWELL LDFL	CONESTOGA, Lancaster, PA	Pass	State
2026-03-04	MARKWEST LIBERTY BLUESTONE LLC/VOLL COMP STA	EVANS CITY, Butler, PA	Pass	State
2026-03-04	EQT ARO LLC/VARGO COMP STA — high-priority violation on file	TROUT RUN, Lycoming, PA	Pass	State
2026-03-04	REGENCY MARCELLUS GAS GATHERING LLC/TAYLOR COMP STA	CANTON, Bradford, PA	Pass	State
2026-03-03	DART CONTAINER CORP/LEOLA	LEOLA, Lancaster, PA	Pass	State
2026-03-03	SCRUBGRASS GENERATING PLT/VENANGO — high-priority violation on file	KENNERDELL, Venango, PA	Pass	State
2026-03-03	HAYSITE REINFORCED PLASTICS LLC/ERIE — high-priority violation on file	ERIE, Erie, PA	Pass	State
2026-03-03	EQT ARO LLC/LARRYS CREEK COMP STA	JERSEY SHORE, Lycoming, PA	Pass	State
2026-03-03	NATL FUEL GAS SUPPLY CORP/MARVINDALE COMP STA	MOUNT JEWETT, McKean, PA	Pass	State
2026-03-02	LAUREL MTN MIDSTREAM OPR LLC/PRAH COMP STA	MCCLELLANDTOWN, Fayette, PA	Pass	State
2026-03-02	INR MIDSTREAM LLC/WEST SUMMIT COMP STA	LAKE LYNN, Fayette, PA	Pass	State
2026-02-27	BOLLES SOUTH WELLPAD — high-priority violation on file	NEW MILFORD, Susquehanna, PA	Pass	State
2026-02-27	CNX MIDSTREAM OPR CO LLC/BELL POINT 2 M&R DEHYDRATION STA	APOLLO, Westmoreland, PA	Pass	State
2026-02-26	KENVUE BRANDS LLC/WHITEMARSH TWP — high-priority violation on file	FORT WASHINGTON, Montgomery, PA	Pass	State
2026-02-26	MARKWEST LIBERTY MIDSTREAM & RESOURCES/LOWRY COMP STA	AVELLA, Washington, PA	Pass	State
2026-02-26	REPSOL OIL & GAS LLC/COLE COMP STA	TROY, Bradford, PA	Pass	State
2026-02-26	JKLM ENERGY LLC/REESE HOLLOW 117 WELL PAD	COUDERSPORT, Potter, PA	Pass	State
2026-02-25	WCAA MIDSTREAM LLC/WEITZ SOUTH 20 COMP STA	ADAMSBURG, Westmoreland, PA	Pass	State
2026-02-25	WILLIAMS FIELD SVC CO/MACNEW COMP STA	HOP BOTTOM, Susquehanna, PA	Pass	State
2026-02-25	JKLM ENERGY LLC/SWEDEN VALLEY 101 PAD	COUDERSPORT, Potter, PA	Pass	State
2026-02-25	EQT ARO LLC/ELBOW PAD B COMP STA — high-priority violation on file	COGAN HOUSE, Lycoming, PA	Pass	State
2026-02-25	JKLM ENERGY/SWEDEN VALLEY 105 WELL PAD	COUDERSPORT, Potter, PA	Pass	State
2026-02-25	EXPAND OPERATING LLC/RU-46 DROPP WELLPAD	SUSQUEHANNA, Susquehanna, PA	Pass	State
2026-02-25	EXPAND OPERATING LLC/RU-71 BLUE BECK WELLPAD	MILFORD, Susquehanna, PA	Pass	State
2026-02-24	GLAXO SMITHKLINE/UPPER PROVIDENCE — high-priority violation on file	COLLEGEVILLE, Montgomery, PA	Pass	State
2026-02-24	EASTERN GAS TRANSMISSION & STORAGE INC/NORTH SUMMIT	HOPWOOD, Fayette, PA	Pass	State
2026-02-24	MARKWEST LIBERTY MIDSTREAM/WELLING COMP STA	CLAYSVILLE, Washington, PA	Pass	State
2026-02-24	EXPAND OPERATING LLC/ALVAREZ BRA WELL PAD	LACEYVILLE, Bradford, PA	Pass	State
2026-02-23	EQT ARO LLC/LYCOMING H&FC COMP STA — high-priority violation on file	TROUT RUN, Lycoming, PA	Pass	State
2026-02-20	REPSOL OIL AND GAS USA/TRACT 587 SFL COMP STA	CANTON, Tioga, PA	Pass	State
2026-02-20	APPALACHIA MIDSTREAM SVC LLC/STAGECOACH COMP STA	WYALUSING, Bradford, PA	Pass	State
2026-02-20	USS/CLAIRTON WORKS — high-priority violation on file	CLAIRTON, Allegheny, PA	Pass	Local
2026-02-19	SUSQUEHANNA GATHERING CO 1 LLC/CDP 2	NEW MILFORD, Susquehanna, PA	Pass	State
2026-02-19	NFG MIDSTREAM COVINGTON LLC/TRACT 007 COMP STA	WELLSBORO, Tioga, PA	Pass	State
2026-02-19	EQT ARTEMIS MIDSTREAM LLC/ROGERS COMP STA — high-priority violation on file	NEW KENSINGTON, Westmoreland, PA	Pass	State
2026-02-19	VANDERMARK, R. PAD 1	MONTROSE, Susquehanna, PA	Pass	State
2026-02-18	JBS SOUDERTON INC/FRANCONIA TWP — high-priority violation on file	SOUDERTON, Montgomery, PA	Pass	State
2026-02-18	ENERGY CTR HBG LLC/ENERGY CTR PAXTON LLC	HARRISBURG, Dauphin, PA	Pass	State
2026-02-18	APPALACHIA MIDSTREAM SVC LLC/WILMOT COMP STA	WYALUSING, Bradford, PA	Pass	State
2026-02-18	USS/CLAIRTON WORKS — high-priority violation on file	CLAIRTON, Allegheny, PA	Pass	Local
2026-02-17	CHESTNUT VALLEY LDFL LLC/GERMAN TWP — high-priority violation on file	MC CLELLANDTOWN, Fayette, PA	Pass	State
2026-02-17	NFG MIDSTREAM COVINGTON LLC/COVINGTON COMP STA	COVINGTON, Tioga, PA	Pass	State
2026-02-17	COMMANDER NAVY REGION MIDATLANTIC/HOST S	PHILADELPHIA, Philadelphia, PA	Pass	Local
2026-02-17	COMMANDER NAVY REGION MIDATLANTIC/HOST S	PHILADELPHIA, Philadelphia, PA	Pass	Local
2026-02-16	TRANSCONTINENTAL GAS/SALLADASBURG STATION 520	JERSEY SHORE, Lycoming, PA	Pass	State
2026-02-16	DIVERSIFIED PROD CO LLC/STATE GAME LANDS COMP STA	MANONING TOWNSHIP, Armstrong, PA	Pass	State
2026-02-16	DIVERSIFIED PROD LLC/PINE CREEK COMP STA	PINE CREEK TOWNSHIP, Jefferson, PA	Pass	State
2026-02-13	EXPAND OPERATING LLC/LU-06 FLICKS RUN EAST WELL PAD	TROUT RUN, Lycoming, PA	Pass	State
2026-02-12	TOWER HEALTH SYS/READING HOSP	READING, Berks, PA	Pass	State
2026-02-12	MARKWEST LIBERTY MIDSTREAM & RESOURCES/NANCY STEWART	MOUNT PLEASANT, Washington, PA	Pass	State

Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.