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 |
|---|---|---|---|---|
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Fail | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Fail | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-19 | MARKWEST LIBERTY BLUESTONE LLC/BLUESTONE GAS PROC PLT | EVANS CITY, Butler, PA | Pass | State |
| 2026-05-19 | NORTHEAST WPCP/PHILA — high-priority violation on file | PHILADELPHIA, Philadelphia, PA | Pass | Local |
| 2026-05-19 | PINE HILL QUARRY | NORTH SMITHFIELD, Providence, RI | Pending | U.S. EPA |
| 2026-05-19 | SANDERS BROTHERS CONSTRUCTION COMPANY INC BERKELEY PLANT | SUMMERVILLE, Berkeley, SC | Pass | State |
| 2026-05-19 | NORTHERN STATES POWER COMPANY | SIOUX FALLS, Minnehaha, SD | Pass | State |
| 2026-05-19 | GULF COAST GROWTH VENTURES PROJECT | GREGORY, San Patricio, TX | Pass | State |
| 2026-05-19 | GULF COAST GROWTH VENTURES PROJECT | GREGORY, San Patricio, TX | Pass | State |
| 2026-05-19 | GULF COAST GROWTH VENTURES PROJECT | GREGORY, San Patricio, TX | Pass | State |
| 2026-05-19 | GULF COAST GROWTH VENTURES PROJECT | GREGORY, San Patricio, TX | Pass | State |
| 2026-05-19 | GULF COAST GROWTH VENTURES PROJECT | GREGORY, San Patricio, TX | Pass | State |
| 2026-05-19 | GULF COAST GROWTH VENTURES PROJECT | GREGORY, San Patricio, TX | Pass | State |
| 2026-05-19 | BIG WEST OIL | NORTH SALT LAKE, Davis, UT | Pass | State |
| 2026-05-19 | AMERICAN PACKAGING CORP - DE FOREST | DEFOREST, Dane, WI | Pass | State |
| 2026-05-19 | WE ENERGIES PORT WASHINGTON GENERATING STATION | PORT WASHINGTON, Pepin, WI | Pass | State |
| 2026-05-19 | KOHLER CO - METALS PROCESSING COMPLEX | KOHLER, Taylor, WI | Pass | State |
| 2026-05-19 | OMNIS PLEASANTS, LLC, PLEASANTS POWER STATION | WILLOW ISLAND, Pleasants, WV | Pass | State |
| 2026-05-19 | OMNIS PLEASANTS, LLC, PLEASANTS POWER STATION | WILLOW ISLAND, Pleasants, WV | Pass | State |
| 2026-05-19 | 50 BUTTES PLANT (THUNDER CREEK GAS SERVICES, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-05-19 | 50 BUTTES PLANT (THUNDER CREEK GAS SERVICES, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-05-19 | 50 BUTTES PLANT (THUNDER CREEK GAS SERVICES, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-05-19 | 50 BUTTES PLANT (THUNDER CREEK GAS SERVICES, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-05-19 | 50 BUTTES PLANT (THUNDER CREEK GAS SERVICES, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-05-19 | 50 BUTTES PLANT (THUNDER CREEK GAS SERVICES, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-05-19 | 50 BUTTES PLANT (THUNDER CREEK GAS SERVICES, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-05-19 | 50 BUTTES PLANT (THUNDER CREEK GAS SERVICES, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-05-19 | CHEYENNE PLANT (DYNO NOBEL INC) — high-priority violation on file | CHEYENNE, Laramie, WY | Pass | State |
| 2026-05-19 | CHEYENNE PLANT (DYNO NOBEL INC) — high-priority violation on file | CHEYENNE, Laramie, WY | Pass | State |
| 2026-05-19 | CHEYENNE PLANT (DYNO NOBEL INC) — high-priority violation on file | CHEYENNE, Laramie, WY | Pass | State |
| 2026-05-19 | CHEYENNE PLANT (DYNO NOBEL INC) — high-priority violation on file | CHEYENNE, Laramie, WY | Pass | State |
| 2026-05-19 | CHEYENNE PLANT (DYNO NOBEL INC) — high-priority violation on file | CHEYENNE, Laramie, WY | Pass | State |
| 2026-05-19 | CHEYENNE PLANT (DYNO NOBEL INC) — high-priority violation on file | CHEYENNE, Laramie, WY | Pass | State |
| 2026-05-19 | CHEYENNE PLANT (DYNO NOBEL INC) — high-priority violation on file | CHEYENNE, Laramie, WY | Pass | State |
| 2026-05-19 | CHEYENNE PLANT (DYNO NOBEL INC) — high-priority violation on file | CHEYENNE, Laramie, WY | Pass | State |
| 2026-05-18 | ALASKA VILLAGE ELECTRIC COOPERATIVE / BETHEL POWER PLANT | BETHEL, Bethel (CA), AK | Pass | State |
| 2026-05-18 | ALASKA VILLAGE ELECTRIC COOPERATIVE / BETHEL POWER PLANT | BETHEL, Bethel (CA), AK | Pass | State |
| 2026-05-18 | INTERNATIONAL PAPER COMPANY | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-05-18 | INTERNATIONAL PAPER COMPANY | MODESTO, Stanislaus, CA | Pass | Local |
| 2026-05-18 | SIGECO - FB CULLEY GENERATING STATION | NEWBURGH, Warrick, IN | Pass | State |
| 2026-05-18 | RUMPKE OF KENTUCKY INC | BUTLER, Pendleton, KY | Pass | State |
| 2026-05-18 | RAVEN POWER FORT SMALLWOOD LLC | CURTIS BAY, Anne Arundel, MD | Pass | State |
| 2026-05-18 | CENTRAL STONE COMPANY FT BELLE QUARRY CS31 | FLORISSANT, St. Louis, MO | Pass | State |
| 2026-05-18 | CENTRAL STONE COMPANY FT BELLE QUARRY CS31 | FLORISSANT, St. Louis, MO | Pass | State |
| 2026-05-18 | CENTRAL STONE COMPANY FT BELLE QUARRY CS31 | FLORISSANT, St. Louis, MO | Pass | State |
| 2026-05-18 | YELLOWSTONE POWER PLANT — high-priority violation on file | BILLINGS, Yellowstone, MT | Pass | State |
| 2026-05-18 | ONEOK ROCKIES MIDSTREAM, L.L.C. - ANTELOPE COMPRESSOR STATION - AQ | NEW TOWN, McKenzie, ND | N/A | State |
| 2026-05-18 | FADEAWAY RIDGE COMPRESSOR STATION | ARTESIA, Eddy, NM | Pass | State |
| 2026-05-18 | FADEAWAY RIDGE COMPRESSOR STATION | ARTESIA, Eddy, NM | Pass | State |
| 2026-05-18 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-18 | IRONROCK CAPITAL, INC. — high-priority violation on file | CANTON, Stark, OH | Pass | State |
| 2026-05-18 | NORTHWEST TENNESSEE DISPOSAL CORPORATION | UNION CITY, Obion, TN | Pass | State |
| 2026-05-18 | GOEN STEEPHOLLOW 5 COMPRESSOR STATION | BRYAN, Brazos, TX | Pass | State |
| 2026-05-18 | GOEN STEEPHOLLOW 5 COMPRESSOR STATION | BRYAN, Brazos, TX | Pass | State |
| 2026-05-18 | GOEN STEEPHOLLOW 5 COMPRESSOR STATION | BRYAN, Brazos, TX | Pass | State |
| 2026-05-18 | HF SINCLAIR WOODS CROSS REFINERY (FORMERLY HOLLY) | WOODS CROSS, Davis, UT | Pass | State |
| 2026-05-18 | ANTERO MIDSTREAM LLC, MIDDLEBOURNE IV | MIDDLEBOURNE, Tyler, WV | Pass | State |
| 2026-05-18 | HOUSE CREEK MAINLINE COMPRESSOR STATION (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-05-18 | HOUSE CREEK MAINLINE COMPRESSOR STATION (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-05-18 | HOUSE CREEK MAINLINE COMPRESSOR STATION (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-05-18 | HOUSE CREEK MAINLINE COMPRESSOR STATION (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-05-18 | HOUSE CREEK MAINLINE COMPRESSOR STATION (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-05-18 | HOUSE CREEK MAINLINE COMPRESSOR STATION (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-05-18 | HOUSE CREEK MAINLINE COMPRESSOR STATION (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-05-18 | HOUSE CREEK MAINLINE COMPRESSOR STATION (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-05-16 | SALT RIVER PROJECT - SANTAN GENERATING STATION | MARICOPA COUNTY, Maricopa, AZ | Pending | Local |
| 2026-05-15 | CHENEY LIME & CEMENT COMPANY | ALABASTER, Shelby, AL | Pass | State |
| 2026-05-15 | CHENEY LIME & CEMENT COMPANY | ALABASTER, Shelby, AL | Pass | State |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.