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 |
|---|---|---|---|---|
| 2025-12-05 | MONONGAHELA POWER COMPANY, FORT MARTIN STATION | MAIDSVILLE, Monongalia, WV | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-05 | MICROSOFT CHEYENNE DATA CENTER (MICROSOFT CORPORATION) | CHEYENNE, Laramie, WY | Pass | State |
| 2025-12-04 | DESOTO GATHERING COMPANY LLC - CHARLEY CPF-3 | HEBER SPRINGS, Cleburne, AR | Pass | State |
| 2025-12-04 | ALBEMARLE CORPORATION - WEST PLANT | MAGNOLIA, Columbia, AR | Pass | State |
| 2025-12-04 | MERIT ENERGY COMPANY, LLC - TOBEY COMPRESSOR STATION | CHARLESTON, Franklin, AR | Pass | State |
| 2025-12-04 | DESOTO GATHERING COMPANY LLC - YELLOWSTONE CPF-2 | QUITMAN, Van Buren, AR | Pass | State |
| 2025-12-04 | INTEL CORP - OCOTILLO CAMPUS — high-priority violation on file | MARICOPA COUNTY, Maricopa, AZ | Pass | Local |
| 2025-12-04 | MOSS LANDING POWER COMPANY LLC (FRMLY DYNEGY MOSS LANDING LLC) | MOSS LANDING, Monterey, CA | Pass | Local |
| 2025-12-04 | LUNDAY-THAGARD CO DBA WORLD OIL REFINING — high-priority violation on file | SOUTH GATE, Los Angeles, CA | Pass | Local |
| 2025-12-04 | SO CAL GAS CO/PLAYA DEL REY STORAGE | PLAYA DEL REY, Los Angeles, CA | Pass | Local |
| 2025-12-04 | BALL WESTERN CAN COMPANY | OAKDALE, Stanislaus, CA | Pass | Local |
| 2025-12-04 | BALL WESTERN CAN COMPANY | OAKDALE, Stanislaus, CA | Pass | Local |
| 2025-12-04 | BALL WESTERN CAN COMPANY | OAKDALE, Stanislaus, CA | Pass | Local |
| 2025-12-04 | ROHM & HAAS ELECTRONIC MATERIALS,CMP,INC | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | ROHM & HAAS ELECTRONIC MATERIALS,CMP,INC | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | ROHM & HAAS ELECTRONIC MATERIALS,CMP,INC | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | ROHM & HAAS ELECTRONIC MATERIALS,CMP,INC | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | ROHM & HAAS ELECTRONIC MATERIALS,CMP,INC | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | CHRISTIANA CARE HEALTH SERVICES - CHRISTIANA HOSPITAL | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | CHRISTIANA CARE HEALTH SERVICES - CHRISTIANA HOSPITAL | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | CHRISTIANA CARE HEALTH SERVICES - CHRISTIANA HOSPITAL | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | CHRISTIANA CARE HEALTH SERVICES - CHRISTIANA HOSPITAL | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | CHRISTIANA CARE HEALTH SERVICES - CHRISTIANA HOSPITAL | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | CHRISTIANA CARE HEALTH SERVICES - CHRISTIANA HOSPITAL | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | CHRISTIANA CARE HEALTH SERVICES - CHRISTIANA HOSPITAL | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | CHRISTIANA CARE HEALTH SERVICES - CHRISTIANA HOSPITAL | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | CHRISTIANA CARE HEALTH SERVICES - CHRISTIANA HOSPITAL | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | CHRISTIANA CARE HEALTH SERVICES - CHRISTIANA HOSPITAL | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | CHRISTIANA CARE HEALTH SERVICES - CHRISTIANA HOSPITAL | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | CHRISTIANA CARE HEALTH SERVICES - CHRISTIANA HOSPITAL | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | CHRISTIANA CARE HEALTH SERVICES - CHRISTIANA HOSPITAL | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | CHRISTIANA CARE HEALTH SERVICES - CHRISTIANA HOSPITAL | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | CHRISTIANA CARE HEALTH SERVICES - CHRISTIANA HOSPITAL | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | CHRISTIANA CARE HEALTH SERVICES - CHRISTIANA HOSPITAL | NEWARK, New Castle, DE | Pass | State |
| 2025-12-04 | LANGBOARD - WILLACOOCHEE — high-priority violation on file | WILLACOOCHEE, Atkinson, GA | Fail | State |
| 2025-12-04 | BUILDING MATERIALS MANUFACTURING LLC | SAVANNAH, Chatham, GA | Pass | State |
| 2025-12-04 | SOUTHERN LNG CO., LLC - ELBA ISLAND LNG TERMINAL - (KINDER MORGAN, INC.) — high-priority violation on file | SAVANNAH, Chatham, GA | Pass | State |
| 2025-12-04 | SOUTHERN LNG CO., LLC - ELBA ISLAND LNG TERMINAL - (KINDER MORGAN, INC.) — high-priority violation on file | SAVANNAH, Chatham, GA | Pass | State |
| 2025-12-04 | SOUTHERN LNG CO., LLC - ELBA ISLAND LNG TERMINAL - (KINDER MORGAN, INC.) — high-priority violation on file | SAVANNAH, Chatham, GA | Pass | State |
| 2025-12-04 | SOUTHERN LNG CO., LLC - ELBA ISLAND LNG TERMINAL - (KINDER MORGAN, INC.) — high-priority violation on file | SAVANNAH, Chatham, GA | Pass | State |
| 2025-12-04 | GA POWER CO. PLANT YATES | NEWNAN, Coweta, GA | Pass | State |
| 2025-12-04 | WASHINGTON COUNTY POWER, LLC | SANDERSVILLE, Washington, GA | Pass | State |
| 2025-12-04 | HOMELAND ENERGY SOLUTIONS LLC — high-priority violation on file | LAWLER, Chickasaw, IA | Pass | State |
| 2025-12-04 | HOMELAND ENERGY SOLUTIONS LLC — high-priority violation on file | LAWLER, Chickasaw, IA | Pass | State |
| 2025-12-04 | SUPERIOR CONSTRUCTION AND EXCAVATING INC 00684 | MERIDIAN, Ada, ID | Pass | State |
| 2025-12-04 | NIKKEI MC ALUMINUM AMERICA INC | COLUMBUS, Bartholomew, IN | Pass | State |
| 2025-12-04 | US STEEL CORPORATION GARY WORKS — high-priority violation on file | GARY, Lake, IN | Pass | State |
| 2025-12-04 | BP PRODUCTS NORTH AMERICA INC WHITING BUSINESS UNIT — high-priority violation on file | WHITING, Lake, IN | Pass | State |
| 2025-12-04 | BP PRODUCTS NORTH AMERICA INC WHITING BUSINESS UNIT — high-priority violation on file | WHITING, Lake, IN | Pass | State |
| 2025-12-04 | BP PRODUCTS NORTH AMERICA INC WHITING BUSINESS UNIT — high-priority violation on file | WHITING, Lake, IN | Pass | State |
| 2025-12-04 | BP PRODUCTS NORTH AMERICA INC WHITING BUSINESS UNIT — high-priority violation on file | WHITING, Lake, IN | Pass | State |
| 2025-12-04 | LOUISVILLE GAS AND ELECTRIC COMPANY CANE RUN GENERATING STATION | LOUISVILLE, Jefferson, KY | Pass | Local |
| 2025-12-04 | LOUISVILLE MEDICAL CENTER STEAM PLANT | LOUISVILLE, Jefferson, KY | Pass | Local |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.