EPA Air · stack tests by year
Air-emissions stack tests in 2025
- 26,291Stack tests
A stack test measures what a source actually emits, at the stack, against the limit in its permit.
States, 2025
- California 5,390
- Ohio 2,213
- New Mexico 1,801
- Indiana 1,619
- Florida 1,419
- Wyoming 1,362
- Georgia 1,233
- Oklahoma 1,229
- Pennsylvania 951
- Missouri 768
- Alabama 693
- Mississippi 688
- Arkansas 619
- Iowa 500
- Colorado 405
- Michigan 387
- Texas 308
- North Carolina 275
- Illinois 264
- Washington 251
- Wisconsin 245
- Minnesota 238
- West Virginia 224
- Delaware 212
- South Carolina 210
- Kentucky 204
- Kansas 202
- Connecticut 178
- Utah 175
- Montana 174
- Virginia 170
- Tennessee 168
- Alaska 152
- Nebraska 145
- North Dakota 143
- Maine 131
- New York 124
- Louisiana 117
- Arizona 116
- Idaho 111
- Nevada 73
- New Hampshire 59
- Massachusetts 59
- Oregon 56
- Hawaii 53
- Maryland 51
- South Dakota 46
- Rhode Island 30
- District of Columbia 28
- Puerto Rico 14
- Vermont 4
- New Jersey 4
Other years
Air-emissions stack tests recorded in 2025
| Date | Facility | Where | Kind | Agency |
|---|---|---|---|---|
| 2025-11-19 | BLUE RACER MIDSTREAM LLC - BELMONT CO FIELD STATION #1 | BARNESVILLE, Belmont, OH | Pass | State |
| 2025-11-19 | ASCENT RESOURCES - UTICA LLC - ALBERT KKW BL | BARNESVILLE, Belmont, OH | Pass | State |
| 2025-11-19 | ASCENT RESOURCES - UTICA LLC - ALBERT KKW BL | BARNESVILLE, Belmont, OH | Pass | State |
| 2025-11-19 | ASCENT RESOURCES - UTICA LLC - ALBERT KKW BL | BARNESVILLE, Belmont, OH | Pass | State |
| 2025-11-19 | ASCENT RESOURCES - UTICA LLC - MALDON WRN BL | BARNESVILLE, Belmont, OH | Pass | State |
| 2025-11-19 | ASCENT RESOURCES - UTICA LLC - MALDON WRN BL | BARNESVILLE, Belmont, OH | Pass | State |
| 2025-11-19 | ASCENT RESOURCES - UTICA LLC - MALDON WRN BL | BARNESVILLE, Belmont, OH | Pass | State |
| 2025-11-19 | EQM OLYMPUS MIDSTREAM, LLC - CATAPULT CS | MARTINS FERRY, Belmont, OH | Pass | State |
| 2025-11-19 | EQM OLYMPUS MIDSTREAM, LLC - CATAPULT CS | MARTINS FERRY, Belmont, OH | Pass | State |
| 2025-11-19 | EQM OLYMPUS MIDSTREAM, LLC - CATAPULT CS | MARTINS FERRY, Belmont, OH | Pass | State |
| 2025-11-19 | ASCENT RESOURCES-UTICA, LLC - BROWN WSG GR | KIMBOLTON, Guernsey, OH | Pass | State |
| 2025-11-19 | ASCENT RESOURCES-UTICA, LLC - BROWN WSG GR | KIMBOLTON, Guernsey, OH | Pass | State |
| 2025-11-19 | ASCENT RESOURCES-UTICA, LLC - BROWN WSG GR | KIMBOLTON, Guernsey, OH | Pass | State |
| 2025-11-19 | TAIT ELECTRIC GENERATING STATION | DAYTON, Montgomery, OH | Pass | State |
| 2025-11-19 | BUCK CO LLC/QUARRYVILLE — high-priority violation on file | QUARRYVILLE, Lancaster, PA | Pass | State |
| 2025-11-19 | YORK GROUP INC/BLACK BRIDGE RD | YORK, York, PA | Pass | State |
| 2025-11-19 | SUNOCO MIDSTREAM LLC/DUPONT TERMINAL | PITTSTON, Luzerne, PA | Pass | State |
| 2025-11-19 | MCC INTL/MILLER CENT CAST INC/MCDONALD PLT — high-priority violation on file | MC DONALD, Washington, PA | Pass | State |
| 2025-11-19 | EASTERN GAS TRANS & STORAGE INC/CENTRE COMP STA | PLEASANT GAP, Centre, PA | Pass | State |
| 2025-11-19 | EXPAND OPERATING LLC/MASSO SUS PAD | MESHOPPEN, Susquehanna, PA | Pass | State |
| 2025-11-19 | EXPAND OPERATING LLC/RU-09 HUMBERT III PAD | NEW MILFORD, Susquehanna, PA | Pass | State |
| 2025-11-19 | EXPAND OPERATING LLC/RU-20 ROMAN PAD | NEW MILFORD, Susquehanna, PA | Pass | State |
| 2025-11-19 | GERDAU AMERISTEEL US INC | JACKSON, Madison, TN | Incomplete | State |
| 2025-11-19 | VALERO REFINING COMPANY-TN LLC | MEMPHIS, Shelby, TN | Pass | Local |
| 2025-11-19 | PACIFICORP LAKESIDE (SUMMIT VINEYARD) | VINEYARD, Utah, UT | Pass | State |
| 2025-11-19 | US ENERGY DEPT - HANFORD — high-priority violation on file | RICHLAND, Benton, WA | Pending | State |
| 2025-11-19 | WESTROCK LONGVIEW LLC — high-priority violation on file | LONGVIEW, Cowlitz, WA | Pass | State |
| 2025-11-19 | MOLSON COORS USA LLC | MILWAUKEE, Monroe, WI | Pass | State |
| 2025-11-19 | KENTUCKY POWER COMPANY, MITCHELL PLANT | MOUNDSVILLE, Marshall, WV | Pass | State |
| 2025-11-19 | ANTERO MIDSTREAM LLC, MOUNTAIN STATION | PENNSBORO, Tyler, WV | Pass | State |
| 2025-11-19 | HF SINCLAIR PARCO REFINING LLC — high-priority violation on file | SINCLAIR, Carbon, WY | Pass | State |
| 2025-11-19 | HF SINCLAIR PARCO REFINING LLC — high-priority violation on file | SINCLAIR, Carbon, WY | Pass | State |
| 2025-11-19 | PINEDALE COMPLEX (HARVEST MIDSTREAM COMPANY) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2025-11-19 | PINEDALE COMPLEX (HARVEST MIDSTREAM COMPANY) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2025-11-19 | PINEDALE COMPLEX (HARVEST MIDSTREAM COMPANY) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2025-11-19 | PINEDALE COMPLEX (HARVEST MIDSTREAM COMPANY) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2025-11-19 | PINEDALE COMPLEX (HARVEST MIDSTREAM COMPANY) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2025-11-19 | PINEDALE COMPLEX (HARVEST MIDSTREAM COMPANY) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2025-11-19 | PINEDALE COMPLEX (HARVEST MIDSTREAM COMPANY) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2025-11-19 | PINEDALE COMPLEX (HARVEST MIDSTREAM COMPANY) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2025-11-18 | TARGA BADLANDS JUNCTION COMPRESSOR STATION | MCKENZIE COUNTY, McKenzie, ND | Pass | U.S. EPA |
| 2025-11-18 | TARGA BADLANDS JUNCTION COMPRESSOR STATION | MCKENZIE COUNTY, McKenzie, ND | Pass | U.S. EPA |
| 2025-11-18 | HILCORP ALASKA, LLC / BEAVER CREEK PRODUCTION FACILITY | KENAI, Kenai Peninsula, AK | Pass | State |
| 2025-11-18 | SOUTHERN NATURAL GAS | ANNISTON, Calhoun, AL | Pass | State |
| 2025-11-18 | CEMEX SOUTHEAST LLC | DEMOPOLIS, Marengo, AL | Pass | State |
| 2025-11-18 | CEMEX SOUTHEAST LLC | DEMOPOLIS, Marengo, AL | Pass | State |
| 2025-11-18 | CEMEX SOUTHEAST LLC | DEMOPOLIS, Marengo, AL | Pass | State |
| 2025-11-18 | DESOTO GATHERING COMPANY, LLC.-STONEFLY CPF 1 | SIDON, Cleburne, AR | Pass | State |
| 2025-11-18 | FLYWHEEL ENERGY COMPANY - PUMA NORTH CPF-1 | WILBURN, Cleburne, AR | Pass | State |
| 2025-11-18 | USMC - YERMO LOGISTICS CNTR | BARSTOW, San Bernardino, CA | Pass | Local |
| 2025-11-18 | ULTRAMAR INC | WILMINGTON, Los Angeles, CA | Fail | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
| 2025-11-18 | ELK HILLS POWER LLC | TUPMAN, Kern, CA | Pass | Local |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.