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 |
|---|---|---|---|---|
| 2026-01-29 | VALERO RENEWABLE FUELS COMPANY LLC DBA VALERO BLUFFTON PLANT | BLUFFTON, Wells, IN | Pass | State |
| 2026-01-29 | VALERO RENEWABLE FUELS COMPANY LLC DBA VALERO BLUFFTON PLANT | BLUFFTON, Wells, IN | Pass | State |
| 2026-01-29 | VALERO RENEWABLE FUELS COMPANY LLC DBA VALERO BLUFFTON PLANT | BLUFFTON, Wells, IN | Pass | State |
| 2026-01-29 | VALERO RENEWABLE FUELS COMPANY LLC DBA VALERO BLUFFTON PLANT | BLUFFTON, Wells, IN | Pass | State |
| 2026-01-29 | COLSTRIP STEAM ELECTRIC STATION | COLSTRIP, Rosebud, MT | Pass | State |
| 2026-01-29 | PAR MONTANA BILLINGS REFINERY | BILLINGS, Yellowstone, MT | Pass | State |
| 2026-01-29 | B.V. HEDRICK GRAVEL AND SAND COMPANY | LILESVILLE, Anson, NC | Pending | State |
| 2026-01-29 | TITAN TREATER PLANT NO1 | JAL, Lea, NM | Pass | State |
| 2026-01-29 | PELICAN COMPRESSOR STATION | JAL, Lea, NM | Pass | State |
| 2026-01-29 | PELICAN COMPRESSOR STATION | JAL, Lea, NM | Pass | State |
| 2026-01-29 | PEPPERIDGE FARM INC. | WILLARD, Huron, OH | Pass | State |
| 2026-01-29 | GEORGIA-PACIFIC WAUNA LLC — high-priority violation on file | CLATSKANIE, Clatsop, OR | Pass | State |
| 2026-01-29 | GEORGIA-PACIFIC WAUNA LLC — high-priority violation on file | CLATSKANIE, Clatsop, OR | Pass | State |
| 2026-01-29 | GEORGIA-PACIFIC WAUNA LLC — high-priority violation on file | CLATSKANIE, Clatsop, OR | Pass | State |
| 2026-01-29 | GEORGIA-PACIFIC WAUNA LLC — high-priority violation on file | CLATSKANIE, Clatsop, OR | Pass | State |
| 2026-01-29 | PA GEN ENERGY CO LLC/HORTON RUN RD COMP STA | CONRAD, Potter, PA | Pass | State |
| 2026-01-29 | COTERRA ENERGY INC/CARPENETTI R PAD 1 | NICHOLSON, Susquehanna, PA | Pass | State |
| 2026-01-29 | COTERRA ENERGY INC/MYERS R PAD 1 | HOP BOTTOM, Susquehanna, PA | Pass | State |
| 2026-01-29 | UNIV OF PGH/PGH CAMPUS | PITTSBURGH, Allegheny, PA | Pass | Local |
| 2026-01-29 | UNIV OF PGH/PGH CAMPUS | PITTSBURGH, Allegheny, PA | Pending | Local |
| 2026-01-29 | TENNESSEE OPERATIONS OF EASTMAN CHEMICAL COMPANY — high-priority violation on file | KINGSPORT, Sullivan, TN | Pass | State |
| 2026-01-29 | COLOSSUS DATA CENTER | MEMPHIS, Shelby, TN | Pass | Local |
| 2026-01-29 | DOMINION/ODEC - CLOVER POWER STATION — high-priority violation on file | CLOVER, Halifax, VA | Fail | State |
| 2026-01-29 | APPALACHIA MIDSTREAM SERVICES, L.L.C., BUFFALO STATION | BETHANY, Brooke, WV | Pass | State |
| 2026-01-29 | ANTERO MIDSTREAM LLC, PERKINS COMPRESSOR STATION | SALEM, Doddridge, WV | Pass | State |
| 2026-01-29 | ANTERO MIDSTREAM LLC, SOUTH CANTON STATION | WEST UNION, Doddridge, WV | Pass | State |
| 2026-01-29 | DAVE JOHNSTON (PACIFICORP) | GLENROCK, Converse, WY | Pass | State |
| 2026-01-29 | DAVE JOHNSTON (PACIFICORP) | GLENROCK, Converse, WY | Pass | State |
| 2026-01-29 | DAVE JOHNSTON (PACIFICORP) | GLENROCK, Converse, WY | Pass | State |
| 2026-01-29 | DAVE JOHNSTON (PACIFICORP) | GLENROCK, Converse, WY | Pass | State |
| 2026-01-29 | COLONY PLANT (BENTONITE PERFORMANCE MINERALS) | COLONY, Crook, WY | Pass | State |
| 2026-01-29 | COLONY PLANT (BENTONITE PERFORMANCE MINERALS) | COLONY, Crook, WY | Pass | State |
| 2026-01-29 | COLONY PLANT (BENTONITE PERFORMANCE MINERALS) | COLONY, Crook, WY | Pass | State |
| 2026-01-28 | US AIR FORCE (EIELSON) / EIELSON AIR FORCE BASE — high-priority violation on file | FAIRBANKS, Fairbanks North Star, AK | Pass | State |
| 2026-01-28 | US AIR FORCE (EIELSON) / EIELSON AIR FORCE BASE — high-priority violation on file | FAIRBANKS, Fairbanks North Star, AK | Pass | State |
| 2026-01-28 | NEXTERA ENERGY PIPELINE HOLDINGS (LOWMAN), INC. | BUTLER, Choctaw, AL | Pass | State |
| 2026-01-28 | HYUNDAI MOTOR MANUFACTURING ALABAMA LLC. | MONTGOMERY, Montgomery, AL | Pass | State |
| 2026-01-28 | LHOIST NORTH AMERICA OF ALABAMA, LLC | CALERA, Shelby, AL | Pass | State |
| 2026-01-28 | ALABAMA POWER COMPANY (MILLER POWER PLANT) | QUINTON, Jefferson, AL | Pass | Local |
| 2026-01-28 | VULCAN MATERIALS — high-priority violation on file | MARICOPA COUNTY, Maricopa, AZ | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | PG&E | HOLT, San Joaquin, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | WOODLAND GENERATION STATION | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-01-28 | DCP OPERATING CO - LUCERNE 2 GAS PLANT — high-priority violation on file | GREELEY AREA, Weld, CO | N/A | State |
| 2026-01-28 | FLORIDA POWER & LIGHT (PTF) | HOMESTEAD, Miami-Dade, FL | Pass | State |
| 2026-01-28 | MIAMI-DADE WATER AND SEWER DEPARTMENT | NORTH MIAMI, Miami-Dade, FL | Pass | State |
| 2026-01-28 | MIAMI-DADE WATER AND SEWER DEPARTMENT | NORTH MIAMI, Miami-Dade, FL | Pass | State |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.