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
- Susquehanna County 117
- Lycoming County 36
- Bradford County 30
- Washington County 29
- Greene County 24
- Philadelphia County 22
- Tioga County 22
- Armstrong County 17
- Wyoming County 13
- Allegheny County 13
- Butler County 12
- Potter County 11
- Mercer County 11
- Westmoreland County 11
- Fayette County 9
- Lawrence County 9
- Montgomery County 7
- Elk County 6
- Lancaster County 6
- York County 6
- Luzerne County 6
- Indiana County 5
- Delaware County 5
- Venango County 5
- Franklin County 5
- Northampton County 5
- Beaver County 4
- Crawford County 4
- Schuylkill County 4
- Dauphin County 4
- Centre County 3
- Jefferson County 3
- Bucks County 3
- Somerset County 3
- Adams County 3
- Bedford County 3
- Berks County 3
Pennsylvania, other years
Air-emissions stack tests recorded in Pennsylvania, 2026
| Date | Facility | Where | Kind | Agency |
|---|---|---|---|---|
| 2026-06-11 | LAUREL MTN MIDSTREAM OPR LLC/DAVIS COMP STA | JEFFERSON, Greene, PA | Pass | State |
| 2026-06-11 | PA GEN ENERGY CO LLC/FISK HOLLOW PAD A | ROULETTE, Potter, PA | Pass | State |
| 2026-06-10 | HEIDELBERG MATERIALS US CEMENT LLC/NAZARETH | NAZARETH, Northampton, PA | Pass | State |
| 2026-06-10 | CONSOL PA COAL CO LLC/BAILEY PREP PLT — high-priority violation on file | WEST FINLEY, Greene, PA | Pending | State |
| 2026-06-10 | PEOPLES NATURAL GAS CO LLC/BELKNAP COMP STA | DAYTON, Armstrong, PA | Pass | State |
| 2026-06-10 | EQM GATHERING OPCO LLC/CALLISTO COMP STA | SYCAMORE, Greene, PA | Pass | State |
| 2026-06-10 | EXPAND OPERATING LLC/MARCUCCI JONES PAD | STEVENSVILLE, Bradford, PA | Pass | State |
| 2026-06-10 | BLACKHILL ENERGY LLC/YOUNG COMP STA — high-priority violation on file | COLUMBIA CROSS ROADS, Bradford, PA | Pass | State |
| 2026-06-09 | MERCK SHARP & DOHME LLC/WEST PT | WEST POINT, Montgomery, PA | Pass | State |
| 2026-06-09 | MTN GATHERING LLC/FORWARD COMP STA | RENFREW, Butler, PA | Pass | State |
| 2026-06-09 | BLUESTONE PIPELINE CO OF PA CDP#5/HARFORD TWP | NEW MILFORD, Susquehanna, PA | Pass | State |
| 2026-06-08 | UGI TEXAS CREEK LLC/CASTLE COMP STA | CANTON, Bradford, PA | Pass | State |
| 2026-06-05 | EXPAND OPERATING LLC/ROSIEMAR SUS PAD | MESHOPPEN, Susquehanna, PA | Pass | State |
| 2026-06-04 | VORTEQ COIL FINISHERS/VALENCIA PLT | VALENCIA, Butler, PA | Pass | State |
| 2026-06-04 | CHAMBERSBURG BORO/ORCHARD PARK GENERATING STA | CHAMBERSBURG, Franklin, PA | Pass | State |
| 2026-06-04 | NEXTERA RENEWABLE FUELS LLC/BLUE RIDGE LDFL | SCOTLAND, Franklin, PA | Pass | State |
| 2026-06-04 | HICKORY RUN ENERGY LLC/NORTH BEAVER TWP | NEW CASTLE, Lawrence, PA | Pass | State |
| 2026-06-04 | WILLIAMS FIELD SVC CO LLC/HAWLEY COMP STA | MONTROSE, Susquehanna, PA | Pass | State |
| 2026-06-04 | CHESAPEAKE APPALACHIA LLC/AMCOR WELLPAD | MESHOPPEN, Wyoming, PA | Pass | State |
| 2026-06-04 | BALL METAL BEVERAGE CONTAINER CORP/PITTSTON | PITTSTON, Luzerne, PA | Pass | State |
| 2026-06-03 | LAUREL MTN MIDSTREAM OPR LLC/SHAMROCK COMP STA — high-priority violation on file | SALEM, Fayette, PA | Pass | State |
| 2026-06-03 | SOUTHWESTERN ENERGY CO/KOZIOL 5H-6H | NEW MILFORD, Susquehanna, PA | Pass | State |
| 2026-06-03 | FRESHPET INC/BETHLEHEM | BETHLEHEM, Northampton, PA | Pass | State |
| 2026-06-03 | BOLLES COMPRESSOR STATION/JESSUP TWP | MONTROSE, Susquehanna, PA | Pass | State |
| 2026-06-02 | GRAYMONT PA INC/PLEASANT GAP & CON-LIME & BELLEFONTE PLTS | BELLEFONTE, Centre, PA | Pass | State |
| 2026-06-02 | APPALACHIA MIDSTREAM SVC LLC/GRANVILLE STA 2 | GRANVILLE SUMMIT, Bradford, PA | Pass | State |
| 2026-06-02 | BLACKHILL ENERGY LLC/BEARDSLEE COMP STA | TROY, Bradford, PA | Pass | State |
| 2026-06-02 | EQM GATHERING OPCO LLC/PISCES COMP STA | CLAYSVILLE, Washington, PA | Pass | State |
| 2026-06-01 | LPR MIDSTREAM PARTNERS LLC/PMG ALLEN STA | ADDISON, Somerset, PA | Pass | State |
| 2026-05-29 | EXPAND OPERATING LLC/N-24 BUCKHORN WELL PAD | MONTROSE, Susquehanna, PA | Pass | State |
| 2026-05-29 | EXPAND OPERATING LLC/NR-23 FOUR BUCKS PAD | SUSQUEHANNA, Susquehanna, PA | Pass | State |
| 2026-05-28 | RSI METAL LITHO/GREENVILLE | GREENVILLE, Mercer, PA | Pass | State |
| 2026-05-28 | PIN OAK MIDSTREAM LLC/TOWNVILLE COMP STA — high-priority violation on file | TOWNVILLE, Crawford, PA | Pass | State |
| 2026-05-28 | RU-64 BOMAN WELL PAD | SUSQUEHANNA, Susquehanna, PA | Pass | State |
| 2026-05-28 | RU-55 CONKLIN PAD | NEW MILFORD, Susquehanna, PA | Pass | State |
| 2026-05-27 | UGI AUBURN GATHERING LLC/AUBURN COMP STA | AUBURN, Susquehanna, PA | Pass | State |
| 2026-05-27 | NEXTERA RENEWABLE FUELS LLC/LYCO LANDFILL LFGTE PLT | MONTGOMERY, Lycoming, PA | Pass | State |
| 2026-05-22 | YORK CNTY SOLID WASTE/YORK CNTY RESOURCE RECOVERY — high-priority violation on file | YORK, York, PA | Pass | State |
| 2026-05-22 | EXPAND OPERATING LLC/MCENANEY BRA PAD | NEW ALBANY, Bradford, PA | Pass | State |
| 2026-05-22 | EXPAND OPERATING LLC/CERCA BRA PAD | WYALUSING, Bradford, PA | Pass | State |
| 2026-05-22 | NORTHEAST WPCP/PHILA — high-priority violation on file | PHILADELPHIA, Philadelphia, PA | Pass | Local |
| 2026-05-21 | BAYER HEALTHCARE LLC/MYERSTOWN | MYERSTOWN, Lebanon, PA | Pass | State |
| 2026-05-21 | MARKWEST LIBERTY BLUESTONE LLC/VOLL COMP STA | EVANS CITY, Butler, PA | Pass | State |
| 2026-05-21 | NORTHEAST WPCP/PHILA — high-priority violation on file | PHILADELPHIA, Philadelphia, PA | Pass | Local |
| 2026-05-20 | YORK CNTY SOLID WASTE/YORK CNTY RESOURCE RECOVERY — high-priority violation on file | YORK, York, PA | Pass | State |
| 2026-05-20 | M SIMON ZOOK CO DBA GOLDEN BARREL PROD/LEOLA | LEOLA, Lancaster, PA | Pass | State |
| 2026-05-20 | REGENCY MARCELLUS GAS GATHERING LLC/SEVERCOOL STA | FORKSTON, Wyoming, PA | Pass | State |
| 2026-05-20 | HAZLETON HILLER LLC/STOCKTON MOUNTAIN ROAD SITE — high-priority violation on file | HAZLETON, Luzerne, PA | Pending | State |
| 2026-05-20 | SNYDER BROS INC/ENSIGN COMPRESSOR STATION | FREEPORT, Armstrong, PA | Pass | State |
| 2026-05-20 | CNX MIDSTREAM OPR CO LLC/BUCKLAND COMP STA | WIND RIDGE, Greene, PA | Pass | State |
| 2026-05-20 | EXPAND OPERATING LLC/NR02 ENDLESS MOUNTAIN WELLPAD | MONTROSE, Susquehanna, PA | Pass | State |
| 2026-05-20 | NORTHEAST WPCP/PHILA — high-priority violation on file | PHILADELPHIA, Philadelphia, PA | Pass | Local |
| 2026-05-19 | MARKWEST LIBERTY BLUESTONE LLC/BLUESTONE GAS PROC PLT | EVANS CITY, Butler, PA | Pass | State |
| 2026-05-19 | NORTHEAST WPCP/PHILA — high-priority violation on file | PHILADELPHIA, Philadelphia, PA | Pass | Local |
| 2026-05-14 | ENERGY TRANSFER M&T/DELMONT FACILITY | DELMONT, Westmoreland, PA | Pass | State |
| 2026-05-14 | EASTERN GAS TRANS & STORAGE INC/ELLISBURG STA | GENESSEE, Potter, PA | Pass | State |
| 2026-05-14 | SNYDER BROS INC/FURNACE RUN COMP STA | ADRIAN, Armstrong, PA | Pass | State |
| 2026-05-14 | BLUESTONE PIPELINE/CDP#1-A | NEW MILFORD, Susquehanna, PA | Pass | State |
| 2026-05-14 | WILLIAMS FIELD SVC CO/POTTER COMP STA | KINGSLEY, Susquehanna, PA | Pass | State |
| 2026-05-14 | USS/CLAIRTON WORKS — high-priority violation on file | CLAIRTON, Allegheny, PA | Pass | Local |
| 2026-05-13 | RW GATHERING LLC/MOSHANNON COMP STA | DRIFTING, Clearfield, PA | Pass | State |
| 2026-05-13 | EQUITRANS LP/JEFFERSON COMP STA | LIPPINCOTT, Greene, PA | Pass | State |
| 2026-05-13 | KC MIDSTREAM SOLUTIONS LLC/OVERBEK STA | RIDGWAY, Elk, PA | Pass | State |
| 2026-05-12 | NATL FUEL GAS SUPPLY/ELLISBURG STA | ELLISBURG, Potter, PA | Pass | State |
| 2026-05-12 | MONROE ENERGY LLC/TRAINER — high-priority violation on file | TRAINER, Delaware, PA | Pass | State |
| 2026-05-12 | SANDY RUN LDFL LLC/HOPEWELL | HOPEWELL, Bedford, PA | Pass | State |
| 2026-05-12 | RW GATHERING LLC/SALEM COMP STA | DERRY, Westmoreland, PA | Pass | State |
| 2026-05-11 | REGENCY MARCELLUS GAS GATHERING LLC/ KORBAN COMP STA | HOP BOTTOM, Susquehanna, PA | Pass | State |
| 2026-05-11 | WCAA UPSTREAM LLC/GRAHAM WELLPAD | DARRAGH, Westmoreland, PA | Pass | State |
| 2026-05-09 | JBS SOUDERTON INC/ALLENTOWN RD | SOUDERTON, Montgomery, PA | Pass | State |
| 2026-05-07 | RW GATHERING LLC/ECKER BERGMAN RD COMP STA | DERRY TWP, Westmoreland, PA | Pass | State |
| 2026-05-07 | EXPAND OPERATING LLC/VALENTINE CPF 1 | CLIFFORD, Susquehanna, PA | Pass | State |
| 2026-05-07 | USS/CLAIRTON WORKS — high-priority violation on file | CLAIRTON, Allegheny, PA | Pass | Local |
| 2026-05-06 | APPALACHIA MIDSTREAM SVC LLC/RATTLESNAKE HILL COMP STA | AUBURN TOWNSHIP, Susquehanna, PA | Pass | State |
| 2026-05-05 | CCL CONTAINER/ADVANCED MONOBLOC AEROSOL DIV — high-priority violation on file | HERMITAGE, Mercer, PA | Pass | State |
| 2026-05-05 | MONROE ENERGY LLC/TRAINER — high-priority violation on file | TRAINER, Delaware, PA | Pass | State |
| 2026-05-05 | HANOVER FOODS CORP/HANOVER CANNERY — high-priority violation on file | HANOVER, York, PA | Pass | State |
| 2026-05-05 | COLUMBIA GAS TRANS LLC/ARTEMAS COMP STA | ARTEMAS, Bedford, PA | Pass | State |
| 2026-05-05 | WILLIAMS FIELD SVC CO LLC/HAWLEY COMP STA | MONTROSE, Susquehanna, PA | Pass | State |
| 2026-05-05 | RANGE RESOURCES APPALACHIA/LAUREL HILL D 17531 PAD | TROUT RUN, Lycoming, PA | Pass | State |
| 2026-05-04 | SURTECO NORTH AMER INC/AUBURN PLT FKA RENEER FILMS — high-priority violation on file | AUBURN, Schuylkill, PA | Pending | State |
| 2026-05-04 | WABTEC US RAIL GROVE CITY ENGINE/MERCER | GROVE CITY, Mercer, PA | Pass | State |
| 2026-05-04 | MARKWEST LIBERTY MIDSTREAM & RESOURCES/REDD COMP STA | WASHINGTON, Washington, PA | Pass | State |
| 2026-05-04 | WILLIAMS FIELD SVC CO/MACNEW COMP STA | HOP BOTTOM, Susquehanna, PA | Pass | State |
| 2026-05-04 | JKLM ENERGY LLC/HEADWATERS 145 WELL PAD | ULYSSES, Potter, PA | Pass | State |
| 2026-05-04 | EXPAND OPERATING LLC/GU-VW MCMAHON WELL PAD | STEVENSVILLE, Bradford, PA | Pass | State |
| 2026-05-01 | EXPAND OPERATING LLC/NR-23 FOUR BUCKS PAD | SUSQUEHANNA, Susquehanna, PA | Pass | State |
| 2026-05-01 | MOGRIDGE, C. PAD 1 — high-priority violation on file | SPRINGVILLE, Susquehanna, PA | Pass | State |
| 2026-04-30 | GRAYMONT PA INC/PLEASANT GAP & CON-LIME & BELLEFONTE PLTS | BELLEFONTE, Centre, PA | Pass | State |
| 2026-04-30 | EASTERN GAS TRANS & STORAGE/RURAL VLY COMP STA | KITTANNING, Armstrong, PA | Pass | State |
| 2026-04-30 | DIVERSIFIED PROD MARCHAND COMP STA | INDIANA, Indiana, PA | Pass | State |
| 2026-04-30 | PENNEX ALUM CO/GREENVILLE PLT | GREENVILLE, Mercer, PA | Pass | State |
| 2026-04-30 | CAREY, R. PAD 1 | KINGSLEY, Susquehanna, PA | Pass | State |
| 2026-04-29 | GOLD BOND BLDG PROD/SHIPPINGPORT | SHIPPINGPORT, Beaver, PA | Pending | State |
| 2026-04-29 | HILCORP ENERGY CO/LACKAWANNOCK LARMON CTL FAC | MERCER, Mercer, PA | Pass | State |
| 2026-04-28 | REGENCY MARCELLUS GAS GATHERING LLC/ROUPP COMP STA | MIFFLIN, Lycoming, PA | Pass | State |
| 2026-04-28 | MARKWEST LIBERTY MIDSTREAM/ CARPENTER COMP STA | WEST ALEXANDRIA, Washington, PA | Pass | State |
| 2026-04-28 | EXPAND OPER LLC/GU-K CAMPBELL ERCOLE WELL PAD | STEVENSVILLE, Bradford, PA | Pass | State |
| 2026-04-27 | SCRUBGRASS GENERATING PLT/VENANGO — high-priority violation on file | KENNERDELL, Venango, PA | Pass | State |
| 2026-04-27 | BKV OPERATING LLC/BAKER WEST COMPRESSOR STATION | FORREST LAKE TWP, Susquehanna, PA | Pass | State |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.