EPA Air · stack tests by year
Air-emissions stack tests in 2026
- 11,110Stack tests
A stack test measures what a source actually emits, at the stack, against the limit in its permit.
States, 2026
- Ohio 1,474
- Indiana 1,010
- California 979
- Florida 795
- Wyoming 755
- New Mexico 724
- Georgia 509
- Pennsylvania 501
- Arkansas 374
- Alabama 357
- Missouri 326
- Texas 316
- Mississippi 263
- Michigan 207
- North Carolina 188
- Colorado 185
- Iowa 167
- Illinois 165
- South Carolina 135
- Wisconsin 135
- West Virginia 114
- Virginia 98
- Idaho 96
- Montana 91
- Tennessee 84
- Minnesota 84
- Delaware 73
- Kentucky 71
- Arizona 71
- Connecticut 68
- Kansas 63
- Nevada 57
- Massachusetts 54
- North Dakota 52
- Nebraska 51
- Utah 51
- Washington 46
- Alaska 45
- New York 43
- South Dakota 34
- District of Columbia 30
- New Hampshire 29
- Maryland 28
- Oregon 27
- Louisiana 26
- Hawaii 21
- Oklahoma 15
- Rhode Island 13
- Puerto Rico 5
- Maine 5
Other years
Air-emissions stack tests recorded in 2026
| Date | Facility | Where | Kind | Agency |
|---|---|---|---|---|
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | SUPERIOR ALUMINUM ALLOYS LLC — high-priority violation on file | NEW HAVEN, Allen, IN | Pass | State |
| 2026-04-01 | SUPERIOR ALUMINUM ALLOYS LLC — high-priority violation on file | NEW HAVEN, Allen, IN | Pass | State |
| 2026-04-01 | SUPERIOR ALUMINUM ALLOYS LLC — high-priority violation on file | NEW HAVEN, Allen, IN | Pass | State |
| 2026-04-01 | SUPERIOR ALUMINUM ALLOYS LLC — high-priority violation on file | NEW HAVEN, Allen, IN | Pass | State |
| 2026-04-01 | SUPERIOR ALUMINUM ALLOYS LLC — high-priority violation on file | NEW HAVEN, Allen, IN | Pass | State |
| 2026-04-01 | SUPERIOR ALUMINUM ALLOYS LLC — high-priority violation on file | NEW HAVEN, Allen, IN | Pass | State |
| 2026-04-01 | SUPERIOR ALUMINUM ALLOYS LLC — high-priority violation on file | NEW HAVEN, Allen, IN | Fail | State |
| 2026-04-01 | PVS TECHNOLOGIES INC — high-priority violation on file | PORTAGE, Porter, IN | Pass | State |
| 2026-04-01 | PVS TECHNOLOGIES INC — high-priority violation on file | PORTAGE, Porter, IN | Pass | State |
| 2026-04-01 | MONTPELIER GENERATING STATION LLC — high-priority violation on file | PONETO, Wells, IN | Pass | State |
| 2026-04-01 | MONTPELIER GENERATING STATION LLC — high-priority violation on file | PONETO, Wells, IN | Pass | State |
| 2026-04-01 | MONTPELIER GENERATING STATION LLC — high-priority violation on file | PONETO, Wells, IN | Pass | State |
| 2026-04-01 | MONTPELIER GENERATING STATION LLC — high-priority violation on file | PONETO, Wells, IN | Pass | State |
| 2026-04-01 | WTE RECYCLING INCORPORATED | GREENFIELD, Franklin, MA | Pending | State |
| 2026-04-01 | WTE RECYCLING INCORPORATED | GREENFIELD, Franklin, MA | Pending | State |
| 2026-04-01 | VICINITY ENERGY LLC | BOSTON, CITY OF, Suffolk, MA | Pending | State |
| 2026-04-01 | METAL CONTAINER CORPORATION — high-priority violation on file | ARNOLD, Jefferson, MO | Pending | State |
| 2026-04-01 | METAL CONTAINER CORPORATION — high-priority violation on file | ARNOLD, Jefferson, MO | Pending | State |
| 2026-04-01 | METAL CONTAINER CORPORATION — high-priority violation on file | ARNOLD, Jefferson, MO | Pending | State |
| 2026-04-01 | METAL CONTAINER CORPORATION — high-priority violation on file | ARNOLD, Jefferson, MO | Pending | State |
| 2026-04-01 | BLACK OAK POWER PRODUCERS LLC | HARTVILLE, Wright, MO | Pass | State |
| 2026-04-01 | BLACK OAK POWER PRODUCERS LLC | HARTVILLE, Wright, MO | Pass | State |
| 2026-04-01 | VENTURE OIL AND GAS INC, HIWANNEE OPERATIONS — high-priority violation on file | WAYNESBORO, Wayne, MS | Pass | State |
| 2026-04-01 | VENTURE OIL AND GAS INC, HIWANNEE OPERATIONS — high-priority violation on file | WAYNESBORO, Wayne, MS | Pass | State |
| 2026-04-01 | VENTURE OIL AND GAS INC, HIWANNEE OPERATIONS — high-priority violation on file | WAYNESBORO, Wayne, MS | Pass | State |
| 2026-04-01 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2026-04-01 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2026-04-01 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2026-04-01 | CALUMET MONTANA REFINING — high-priority violation on file | GREAT FALLS, Cascade, MT | Pass | State |
| 2026-04-01 | NORTHERN BORDER PIPELINE COMPANY - ST. ANTHONY COMPRESSOR STATION - AQ | ST. ANTHONY, Morton, ND | Pass | State |
| 2026-04-01 | CEDAR CANYON 28 COMPRESSOR STATION | MALAGA, Eddy, NM | Pass | State |
| 2026-04-01 | CEDAR CANYON 28 COMPRESSOR STATION | MALAGA, Eddy, NM | Pass | State |
| 2026-04-01 | CEDAR CANYON 28 COMPRESSOR STATION | MALAGA, Eddy, NM | Pass | State |
| 2026-04-01 | CEDAR CANYON 28 COMPRESSOR STATION | MALAGA, Eddy, NM | Pass | State |
| 2026-04-01 | TRACE - HAWK COMPRESSOR STATION | LOCO HILLS, Eddy, NM | Pass | State |
| 2026-04-01 | TRACE - HAWK COMPRESSOR STATION | LOCO HILLS, Eddy, NM | Pass | State |
| 2026-04-01 | TRACE - HAWK COMPRESSOR STATION | LOCO HILLS, Eddy, NM | Pass | State |
| 2026-04-01 | TIGER COMPRESSOR STATION | CARLSBAD, Eddy, NM | Pass | State |
| 2026-04-01 | TIGER COMPRESSOR STATION | CARLSBAD, Eddy, NM | Pass | State |
| 2026-04-01 | TIGER COMPRESSOR STATION | CARLSBAD, Eddy, NM | Pass | State |
| 2026-04-01 | BENT TREE 8 CTB 1 | LA HUERTA, Eddy, NM | Pass | State |
| 2026-04-01 | MAMA JO TB | LOVING, Eddy, NM | Pass | State |
| 2026-04-01 | STRANGER 34 CTB 2 | JAL, Lea, NM | Pass | State |
| 2026-04-01 | GEORGIA-PACIFIC WAUNA LLC — high-priority violation on file | CLATSKANIE, Clatsop, OR | Pass | State |
| 2026-04-01 | GEORGIA-PACIFIC WAUNA LLC — high-priority violation on file | CLATSKANIE, Clatsop, OR | Pass | State |
| 2026-04-01 | GEORGIA-PACIFIC WAUNA LLC — high-priority violation on file | CLATSKANIE, Clatsop, OR | Pass | State |
| 2026-04-01 | GEORGIA-PACIFIC WAUNA LLC — high-priority violation on file | CLATSKANIE, Clatsop, OR | Pass | State |
| 2026-04-01 | GEORGIA-PACIFIC WAUNA LLC — high-priority violation on file | CLATSKANIE, Clatsop, OR | Pass | State |
| 2026-04-01 | VITRO MEADVILLE FLAT GLASS MEADVILLE PLT/CRAWFORD | COCHRANTON, Crawford, PA | Pass | State |
| 2026-04-01 | PIXELLE SPEC SOLUTIONS LLC/SPRING GROVE — high-priority violation on file | SPRING GROVE, York, PA | Fail | State |
| 2026-04-01 | GRAYMONT PA INC/PLEASANT GAP & CON-LIME & BELLEFONTE PLTS | BELLEFONTE, Centre, PA | Pass | State |
| 2026-04-01 | VICTAULIC COMPANY/ALBURTIS FACILITY | ALBURTIS, Lehigh, PA | Pass | State |
| 2026-04-01 | MARKWEST LIBERTY MIDSTREAM/DRYER BOOSTER COMP STA | AVELLA, Washington, PA | Pass | State |
| 2026-04-01 | CNX MIDSTREAM OPR CO LLC/MAMONT COMP STA | APOLLO, Westmoreland, PA | Pass | State |
| 2026-04-01 | REGENCY MARCELLUS GAS GATHERING LLC/OGONTZ WEST COMP STA | CUMMINS TWP, Lycoming, PA | Pass | State |
| 2026-04-01 | REGENCY MARCELLUS GAS GATHERING LLC/OGONTZ WEST COMP STA | CUMMINS TWP, Lycoming, PA | Pass | State |
| 2026-04-01 | WILLIAMS FIELD SVC CO LLC/SHIELDS COMP STA | SPRINGVILLE, Susquehanna, PA | Pass | State |
| 2026-04-01 | NFG MIDSTREAM CLERMONT LLC/CLERMONT WEST COMP STA | EMPORIUM, Elk, PA | Pass | State |
| 2026-04-01 | SHELL CHEM APPALACHIA/SHELL POLYMERS MONACA — high-priority violation on file | MONACA, Beaver, PA | Pass | State |
| 2026-04-01 | SOUTHWESTERN ENERGY CO/TNT LIMITED PARTNERSHIP WEST 6H | NEW MILFORD, Susquehanna, PA | Pass | State |
| 2026-04-01 | EQM GATHERING OPCO LLC/KRYPTONITE COMP STA | WASHINGTON, Washington, PA | Pass | State |
| 2026-04-01 | POWERS, M. PAD 1 | MESHOPPEN, Susquehanna, PA | Pass | State |
| 2026-04-01 | HAWK, J. PAD 1 | MESHOPPEN, Susquehanna, PA | Pass | State |
| 2026-04-01 | TEMPLE UNIV HEALTH SCIENCES CAMPUS/STEAM — high-priority violation on file | PHILADELPHIA, Philadelphia, PA | Pass | Local |
| 2026-04-01 | SIGNAL MOUNTAIN CEMENT COMPANY D/B/A BUZZI UNICEM USA | CHATTANOOGA, Hamilton, TN | Pass | Local |
| 2026-04-01 | SIGNAL MOUNTAIN CEMENT COMPANY D/B/A BUZZI UNICEM USA | CHATTANOOGA, Hamilton, TN | Pass | Local |
| 2026-04-01 | AMAZON DATA SERVICES INC - DCA-060 | STEVENSBURG, Culpeper, VA | Pass | State |
| 2026-04-01 | WARRENTON TRAINING CENTER-STATION B | WARRENTON, Fauquier, VA | Pass | State |
| 2026-04-01 | EASTERN GAS TRANSMISSION AND STORAGE, INC., L. L. TONKIN STATION | WEST UNION, Doddridge, WV | Pass | State |
| 2026-04-01 | MARY'S DRAW (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-04-01 | MARY'S DRAW (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-04-01 | MARY'S DRAW (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-04-01 | MARY'S DRAW (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-04-01 | MARY'S DRAW (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-04-01 | MARY'S DRAW (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-04-01 | MARY'S DRAW (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-04-01 | MARY'S DRAW (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-04-01 | LOST CABIN GAS PLANT (CONTANGO RESOURCES, LLC.) — high-priority violation on file | LOST CABIN, Fremont, WY | Pass | State |
| 2026-04-01 | LOST CABIN GAS PLANT (CONTANGO RESOURCES, LLC.) — high-priority violation on file | LOST CABIN, Fremont, WY | Pass | State |
| 2026-04-01 | LOST CABIN GAS PLANT (CONTANGO RESOURCES, LLC.) — high-priority violation on file | LOST CABIN, Fremont, WY | Pass | State |
| 2026-03-31 | DEMOPOLIS PELLETS, LLC | DEMOPOLIS, Marengo, AL | Pass | State |
| 2026-03-31 | ET GATHERING & PROCESSING LLC. - EAST CHISMVILLE COMPRESSOR STATION | BOONEVILLE, Logan, AR | Pass | State |
| 2026-03-31 | ET GATHERING & PROCESSING LLC. - WITCHERVILLE COMPRESS STATION | HUNTINGTON, Sebastian, AR | Pass | State |
| 2026-03-31 | ALON BAKERSFIELD REFINING — high-priority violation on file | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-03-31 | ALON BAKERSFIELD REFINING — high-priority violation on file | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-03-31 | ALON BAKERSFIELD REFINING — high-priority violation on file | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-03-31 | ALON BAKERSFIELD REFINING — high-priority violation on file | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-03-31 | ALON BAKERSFIELD REFINING — high-priority violation on file | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-03-31 | SAN JOAQUIN REFINING CO — high-priority violation on file | BAKERSFIELD, Kern, CA | Pass | Local |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.