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 |
|---|---|---|---|---|
| 2026-04-28 | ENTERPRISE - CEDAR CANYON COMPRESSOR STATION | MALAGA, Eddy, NM | Pass | State |
| 2026-04-28 | DR. IRELAND TB | LOVING, Eddy, NM | Pass | State |
| 2026-04-28 | DR. IRELAND TB | LOVING, Eddy, NM | Pass | State |
| 2026-04-28 | EIDER COMPRESSOR STATION | MALAGA, Lea, NM | Pass | State |
| 2026-04-28 | EIDER COMPRESSOR STATION | MALAGA, Lea, NM | Pass | State |
| 2026-04-28 | ZIA HILLS CENTRAL FACILITY | MALAGA, Lea, NM | Pass | State |
| 2026-04-28 | ZIA HILLS CENTRAL FACILITY | MALAGA, Lea, NM | Pass | State |
| 2026-04-28 | THE CONTEST CTB | JAL, Lea, NM | Pass | State |
| 2026-04-28 | EMD ACQUISITION, LLC — high-priority violation on file | HENDERSON, Clark, NV | Pass | Local |
| 2026-04-28 | MOMENTIVE PERFORMANCE MATERIALS | WATERFORD, Saratoga, NY | Pass | State |
| 2026-04-28 | ONTARIO COUNTY LFG TO ENERGY FACILITY | STANLEY, Ontario, NY | Pass | State |
| 2026-04-28 | HILCORP ENERGY - POLAND-CLL PRODUCTION FACILITY | POLAND, TOWNSHIP OF, Mahoning, OH | Pass | State |
| 2026-04-28 | HILCORP ENERGY - POLAND-CLL PRODUCTION FACILITY | POLAND, TOWNSHIP OF, Mahoning, OH | Pass | State |
| 2026-04-28 | HILCORP ENERGY - POLAND-CLL PRODUCTION FACILITY | POLAND, TOWNSHIP OF, Mahoning, OH | Pass | State |
| 2026-04-28 | MCWANE DUCTILE - OHIO | COSHOCTON, Coshocton, OH | Pass | State |
| 2026-04-28 | MCWANE DUCTILE - OHIO | COSHOCTON, Coshocton, OH | Pass | State |
| 2026-04-28 | MCWANE DUCTILE - OHIO | COSHOCTON, Coshocton, OH | Pass | State |
| 2026-04-28 | MCWANE DUCTILE - OHIO | COSHOCTON, Coshocton, OH | Pass | State |
| 2026-04-28 | MCWANE DUCTILE - OHIO | COSHOCTON, Coshocton, OH | Pass | State |
| 2026-04-28 | MCWANE DUCTILE - OHIO | COSHOCTON, Coshocton, OH | Pass | State |
| 2026-04-28 | MCWANE DUCTILE - OHIO | COSHOCTON, Coshocton, OH | Pass | State |
| 2026-04-28 | EOG RESOURCES, INC. - GUTHRIE HN FRA PAD | DEERSVILLE, Harrison, OH | Pass | State |
| 2026-04-28 | EOG RESOURCES, INC. - GUTHRIE HN FRA PAD | DEERSVILLE, Harrison, OH | Pass | State |
| 2026-04-28 | EOG RESOURCES, INC. - GUTHRIE HN FRA PAD | DEERSVILLE, Harrison, OH | Pass | State |
| 2026-04-28 | DTE MARIETTA | MARIETTA, Washington, OH | Pass | State |
| 2026-04-28 | GENERAL ALUMINUM | ROOTSTOWN, Portage, OH | Pass | State |
| 2026-04-28 | REDCLIFF MIDSTREAM LLC / REDCLIFF PLANT | MUTUAL, Woodward, OK | Pending | 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 |
| 2026-04-28 | OTTER TAIL POWER COMPANY - ASTORIA STATION | ASTORIA, Deuel, SD | Pass | State |
| 2026-04-28 | MAGELLAN PIPELINE COMPANY LP - SIOUX FALLS TERMINAL | SIOUX FALLS, Minnehaha, SD | Pass | State |
| 2026-04-28 | PETE LIEN & SONS, INC. MAIN PLANT | RAPID CITY, Pennington, SD | Pass | State |
| 2026-04-28 | VALERO REFINING COMPANY-TN LLC | MEMPHIS, Shelby, TN | Pass | Local |
| 2026-04-28 | MEMPHIS CITY STILES WASTEWATER TREATMENT — high-priority violation on file | MEMPHIS, Shelby, TN | Pass | Local |
| 2026-04-28 | HYDRITE CHEMICAL CO. — high-priority violation on file | COTTAGE GROVE, Dane, WI | Pass | State |
| 2026-04-28 | MONONGAHELA POWER COMPANY, HARRISON STATION | HAYWOOD, Harrison, WV | Pass | State |
| 2026-04-28 | MONONGAHELA POWER COMPANY, HARRISON STATION | HAYWOOD, Harrison, WV | Pass | State |
| 2026-04-27 | TRANSCONTINENTAL GAS PIPE LINE COMPANY L | SWEET WATER, Marengo, AL | Pass | State |
| 2026-04-27 | TRANSCONTINENTAL GAS PIPE LINE COMPANY L | SWEET WATER, Marengo, AL | Pass | State |
| 2026-04-27 | TRANSCONTINENTAL GAS PIPE LINE COMPANY L | SWEET WATER, Marengo, AL | Pass | State |
| 2026-04-27 | TSMC PHOENIX PROJECT | MARICOPA COUNTY, Maricopa, AZ | Pass | Local |
| 2026-04-27 | TESORO REFINING & MARKETING CO, LLC — high-priority violation on file | CARSON, Los Angeles, CA | Pass | Local |
| 2026-04-27 | PLAINS END, LLC | ARVADA, Jefferson, CO | Pass | State |
| 2026-04-27 | PUBLIC SERVICE CO - HAYDEN PLT | HAYDEN, Routt, CO | Pass | State |
| 2026-04-27 | PDC ENERGY - LEFFLER 8-21, DONN 1-21 PAD | GREELEY, Weld, CO | N/A | State |
| 2026-04-27 | MIDDLETOWN POWER LLC | MIDDLETOWN, Middlesex, CT | Pass | State |
| 2026-04-27 | MOSAIC FERTILIZER LLC | MULBERRY, Polk, FL | Pass | State |
| 2026-04-27 | FLOWERS BAKERY OF SUWANEE LLC | SUWANEE, Gwinnett, GA | Pass | State |
| 2026-04-27 | AMSTED RAIL (AIR) | KANSAS CITY, Wyandotte, KS | Pass | State |
| 2026-04-27 | CALGON CARBON CORPORATION | BAY ST. LOUI, Hancock, MS | Pass | State |
| 2026-04-27 | CALGON CARBON CORPORATION | BAY ST. LOUI, Hancock, MS | Pass | State |
| 2026-04-27 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2026-04-27 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2026-04-27 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2026-04-27 | CHS INC REFINERY LAUREL | LAUREL, Yellowstone, MT | Pass | State |
| 2026-04-27 | ENTERPRISE - CEDAR CANYON COMPRESSOR STATION | MALAGA, Eddy, NM | Pass | State |
| 2026-04-27 | PAUL FACILITY | MALAGA, Eddy, NM | Pass | State |
| 2026-04-27 | JANIE CONNER FACILITY — high-priority violation on file | MALAGA, Eddy, NM | Pass | State |
| 2026-04-27 | INDIAN FLATS BOOSTER STATION | CARLSBAD, Eddy, NM | Pass | State |
| 2026-04-27 | BRININSTOOL COMPRESSOR STATION | EUNICE, Lea, NM | Pass | State |
| 2026-04-27 | REDCLIFF MIDSTREAM LLC / REDCLIFF PLANT | MUTUAL, Woodward, OK | Pending | 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 |
| 2026-04-27 | EXPAND OPERATING LLC/WOOSMAN PAD | NEW MILFORD, Susquehanna, PA | Pass | State |
| 2026-04-27 | HF SINCLAIR WOODS CROSS REFINERY (FORMERLY HOLLY) | WOODS CROSS, Davis, UT | Pass | State |
| 2026-04-27 | MMSD-JONES ISLAND WATER RECLAMATION FACILITY | MILWAUKEE, Monroe, WI | Pass | State |
| 2026-04-27 | BLUE RACER MIDSTREAM, LLC, FIELD STATION 1 | READER, Wetzel, WV | Pass | State |
| 2026-04-25 | SALT RIVER PROJECT - AGUA FRIA GENERATING STATION | MARICOPA COUNTY, Maricopa, AZ | Pass | Local |
| 2026-04-25 | WATEREE STATION | EASTOVER, Richland, SC | Pass | State |
| 2026-04-24 | FREEPORT MCMORAN - MIAMI SMELTER | MIAMI, Gila, AZ | Pass | State |
| 2026-04-24 | UTAH GAS - DRAGON TRAIL — high-priority violation on file | RANGELY 16.7 MI. S OF, Rio Blanco, CO | Pass | State |
| 2026-04-24 | WHEELABRATOR SOUTH BROWARD, INC | FORT LAUDERDALE, Broward, FL | Pass | State |
| 2026-04-24 | MAS GEORGIA LFG, LLC (RICHLAND CREEK) | BUFORD, Gwinnett, GA | Pass | State |
| 2026-04-24 | MAS GEORGIA LFG, LLC (RICHLAND CREEK) | BUFORD, Gwinnett, GA | Pass | State |
| 2026-04-24 | MAS GEORGIA LFG, LLC (RICHLAND CREEK) | BUFORD, Gwinnett, GA | Pass | State |
| 2026-04-24 | WINNETKA ELECTRIC PLANT | WINNETKA, Cook, IL | Pass | State |
| 2026-04-24 | WINNETKA ELECTRIC PLANT | WINNETKA, Cook, IL | Pass | State |
| 2026-04-24 | ALLISON TRANSMISSION INC SPEEDWAY MAIN CAMPUS — high-priority violation on file | INDIANAPOLIS, Marion, IN | Fail | State |
| 2026-04-24 | TATE & LYLE SOLUTIONS USA LLC — high-priority violation on file | LAFAYETTE, Tippecanoe, IN | Pass | State |
| 2026-04-24 | TATE & LYLE SOLUTIONS USA LLC — high-priority violation on file | LAFAYETTE, Tippecanoe, IN | Pass | State |
| 2026-04-24 | TATE & LYLE SOLUTIONS USA LLC — high-priority violation on file | LAFAYETTE, Tippecanoe, IN | Pass | State |
| 2026-04-24 | WHEELABRATOR BALTIMORE, LP | BALTIMORE, Baltimore (city), MD | Pass | State |
| 2026-04-24 | DTE ST. CLAIR / BELLE RIVER POWER PLANT — high-priority violation on file | CHINA, St. Clair, MI | Fail | State |
| 2026-04-24 | BLUE WATER RENEWABLES — high-priority violation on file | KIMBALL, St. Clair, MI | Pass | State |
| 2026-04-24 | FOREST CITY FACILITY, LLC | FOREST CITY, Holt, MO | Pass | State |
| 2026-04-24 | FOREST CITY FACILITY, LLC | FOREST CITY, Holt, MO | Pass | State |
| 2026-04-24 | FOREST CITY FACILITY, LLC | FOREST CITY, Holt, MO | Pass | State |
| 2026-04-24 | FOREST CITY FACILITY, LLC | FOREST CITY, Holt, MO | Pass | State |
| 2026-04-24 | DUKE ENERGY PROGRESS, LLC - RICHMOND COUNTY TURBINES | HAMLET, Richmond, NC | Pending | State |
| 2026-04-24 | WEST TURKEY TRACK BOOSTER — high-priority violation on file | LOCO HILLS, Eddy, NM | Pass | State |
| 2026-04-24 | USA COMPRESSION - NC SAND DUNES COMPRESSOR STATION | MALAGA, Eddy, NM | Pass | State |
| 2026-04-24 | MESA VERDE WEST CENTRAL GAS LIFT STATION | MALAGA, Lea, NM | Pass | State |
| 2026-04-24 | MESA VERDE WEST CENTRAL GAS LIFT STATION | MALAGA, Lea, NM | Pass | State |
| 2026-04-24 | BIG LIZARD COMPRESSOR STATION | EUNICE, Lea, NM | Pass | State |
| 2026-04-24 | BIG LIZARD COMPRESSOR STATION | EUNICE, Lea, NM | Pass | State |
| 2026-04-24 | BIG LIZARD COMPRESSOR STATION | EUNICE, Lea, NM | Pass | State |
| 2026-04-24 | MUELLER CO. LLC — high-priority violation on file | CHATTANOOGA, Hamilton, TN | Pass | Local |
| 2026-04-24 | NTT GLOBAL DATA CENTERS AMERICAS, INC. | ASHBURN, Loudoun, VA | Pass | State |
| 2026-04-24 | AMAZON DATA SERVICES, INC. IAD-144 IAD-145 | STERLING, Loudoun, VA | Pass | State |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.