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 |
|---|---|---|---|---|
| 2026-04-07 | MARKWEST LIBERTY MIDSTREAM & RESOURCES, L.L.C., MAJORSVILLE | DALLAS, Marshall, WV | Pass | State |
| 2026-04-07 | AUGUSTA-PEBBLE BEACH COMPRESSOR STATION (PRONGHORN MIDSTREAM LLC) | JOHNSON COUNTY, Johnson, WY | Pass | State |
| 2026-04-07 | AUGUSTA-PEBBLE BEACH COMPRESSOR STATION (PRONGHORN MIDSTREAM LLC) | JOHNSON COUNTY, Johnson, WY | Pass | State |
| 2026-04-07 | AUGUSTA-PEBBLE BEACH COMPRESSOR STATION (PRONGHORN MIDSTREAM LLC) | JOHNSON COUNTY, Johnson, WY | Pass | State |
| 2026-04-07 | AUGUSTA-PEBBLE BEACH COMPRESSOR STATION (PRONGHORN MIDSTREAM LLC) | JOHNSON COUNTY, Johnson, WY | Pass | State |
| 2026-04-07 | AUGUSTA-PEBBLE BEACH COMPRESSOR STATION (PRONGHORN MIDSTREAM LLC) | JOHNSON COUNTY, Johnson, WY | Pass | State |
| 2026-04-07 | AUGUSTA-PEBBLE BEACH COMPRESSOR STATION (PRONGHORN MIDSTREAM LLC) | JOHNSON COUNTY, Johnson, WY | Pass | State |
| 2026-04-07 | RINER STATION (SOUTHERN STAR CENTRAL GAS PIPELINE) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-04-07 | BLACKS FORK GAS PLANT (HARVEST MIDSTREAM COMPANY) | GRANGER, Sweetwater, WY | Pass | State |
| 2026-04-07 | BLACKS FORK GAS PLANT (HARVEST MIDSTREAM COMPANY) | GRANGER, Sweetwater, WY | Pass | State |
| 2026-04-07 | BLACKS FORK GAS PLANT (HARVEST MIDSTREAM COMPANY) | GRANGER, Sweetwater, WY | Pass | State |
| 2026-04-06 | HILCORP ALASKA, LLC / BELUGA RIVER UNIT — high-priority violation on file | KENAI, Kenai Peninsula, AK | Pass | State |
| 2026-04-06 | SOUTHERN NATURAL GAS | GALLION, Hale, AL | Pass | State |
| 2026-04-06 | SOUTHERN NATURAL GAS | GALLION, Hale, AL | Pass | State |
| 2026-04-06 | DESOTO GATHERING COMPANY, LLC - NEW QUITMAN CPF-1 | QUITMAN, Faulkner, AR | Pass | State |
| 2026-04-06 | DESOTO GATHERING COMPANY, LLC - MIDGE CPF-1 | SEARCY, White, AR | Pass | State |
| 2026-04-06 | JARVIS TREE SERVICE, INC. | HEBER SPRINGS, Cleburne, AR | Pass | State |
| 2026-04-06 | CRESTONE PEAK - KING 3-65 28-29 | AURORA, Adams, CO | Pass | State |
| 2026-04-06 | CRESTONE PEAK - KING 3-65 28-29 | AURORA, Adams, CO | Pass | State |
| 2026-04-06 | CRESTONE PEAK - KING 3-65 28-29 | AURORA, Adams, CO | Pass | State |
| 2026-04-06 | CRESTONE PEAK - KING 3-65 28-29 | AURORA, Adams, CO | Pass | State |
| 2026-04-06 | WES DJ FT LUPTON/PLATTE VALLEY/LANCASTER — high-priority violation on file | FORT LUPTON, Weld, CO | Pass | State |
| 2026-04-06 | MAS ASB COGEN LLC CHP FACILITY | ATLANTA, Fulton, GA | Pass | State |
| 2026-04-06 | MAS ASB COGEN LLC CHP FACILITY | ATLANTA, Fulton, GA | Pass | State |
| 2026-04-06 | MAS ASB COGEN LLC CHP FACILITY | ATLANTA, Fulton, GA | Pass | State |
| 2026-04-06 | J R SIMPLOT COMPANY-DON SIDING POCATELLO — high-priority violation on file | POCATELLO, Power, ID | Pass | State |
| 2026-04-06 | SUPERIOR ALUMINUM ALLOYS LLC — high-priority violation on file | NEW HAVEN, Allen, IN | Pass | State |
| 2026-04-06 | SUPERIOR ALUMINUM ALLOYS LLC — high-priority violation on file | NEW HAVEN, Allen, IN | Pass | State |
| 2026-04-06 | SUPERIOR ALUMINUM ALLOYS LLC — high-priority violation on file | NEW HAVEN, Allen, IN | Pass | State |
| 2026-04-06 | SUPERIOR ALUMINUM ALLOYS LLC — high-priority violation on file | NEW HAVEN, Allen, IN | Pass | State |
| 2026-04-06 | SUPERIOR ALUMINUM ALLOYS LLC — high-priority violation on file | NEW HAVEN, Allen, IN | Pass | State |
| 2026-04-06 | SUPERIOR ALUMINUM ALLOYS LLC — high-priority violation on file | NEW HAVEN, Allen, IN | Pass | State |
| 2026-04-06 | SUPERIOR ALUMINUM ALLOYS LLC — high-priority violation on file | NEW HAVEN, Allen, IN | Fail | State |
| 2026-04-06 | CITY OF FORT WAYNE THREE RIVERS FILTRATION PLANT — high-priority violation on file | FORT WAYNE, Allen, IN | Pass | State |
| 2026-04-06 | CITY OF FORT WAYNE THREE RIVERS FILTRATION PLANT — high-priority violation on file | FORT WAYNE, Allen, IN | Pass | State |
| 2026-04-06 | CITY OF FORT WAYNE THREE RIVERS FILTRATION PLANT — high-priority violation on file | FORT WAYNE, Allen, IN | Pass | State |
| 2026-04-06 | HURON CASTING, INC (BLUE DIAMOND STEEL CASTING) | PIGEON, Huron, MI | Pass | State |
| 2026-04-06 | MOM BRANDS | NORTHFIELD, Rice, MN | N/A | State |
| 2026-04-06 | ROUGH RIDER BAKKEN G&P LLC, A SUBSIDIARY OF ENERGY TRANSFER, LP - WILD BASIN GAS | WATFORD CITY, McKenzie, ND | N/A | State |
| 2026-04-06 | ROUGH RIDER BAKKEN G&P LLC, A SUBSIDIARY OF ENERGY TRANSFER, LP - WILD BASIN GAS | WATFORD CITY, McKenzie, ND | N/A | State |
| 2026-04-06 | TARGA BADLANDS, LLC - HAWKEYE COMPRESSOR STATION - AQ | KEENE, McKenzie, ND | N/A | State |
| 2026-04-06 | TRACE - HAWK COMPRESSOR STATION | LOCO HILLS, Eddy, NM | Pass | State |
| 2026-04-06 | BENT TREE 9 CTB 2 | LA HUERTA, Eddy, NM | Pass | State |
| 2026-04-06 | FRAC CAT COMPRESSOR STATION | LOVING, Lea, NM | Pass | State |
| 2026-04-06 | FRAC CAT COMPRESSOR STATION | LOVING, Lea, NM | Pass | State |
| 2026-04-06 | UNCLE CHES TANK BATTERY | HOBBS, Lea, NM | Pass | State |
| 2026-04-06 | MARGARITA CTB | MONUMENT, Lea, NM | Pass | State |
| 2026-04-06 | QUEEN KEELY CTB | MONUMENT, Lea, NM | Pass | State |
| 2026-04-06 | MONIKA SOUTH TB | NORTH HOBBS, Lea, NM | Pass | State |
| 2026-04-06 | SQUIER, R. PAD 1 — high-priority violation on file | KINGSLEY, Susquehanna, PA | Pending | State |
| 2026-04-06 | HUSTON, J. PAD 1 | KINGSLEY, Susquehanna, PA | Pass | State |
| 2026-04-06 | EXXONMOBIL BEAUMONT REFINERY — high-priority violation on file | BEAUMONT, Jefferson, TX | N/A | State |
| 2026-04-06 | ALLIANT ENERGY - WPL - COLUMBIA ENERGY CENTER | PARDEEVILLE, Columbia, WI | Pass | State |
| 2026-04-06 | MARKWEST LIBERTY MIDSTREAM & RESOURCES, L.L.C., SHERWOOD | WEST UNION, Doddridge, WV | Pass | State |
| 2026-04-04 | STRYTEN SALINA, LLC (AIR) | SALINA, Saline, KS | Pass | State |
| 2026-04-04 | GILBERTON POWER CO/JOHN B RICH MEM POWER STA | FRACKVILLE, Schuylkill, PA | Pass | State |
| 2026-04-03 | WES DJ FT LUPTON/PLATTE VALLEY/LANCASTER — high-priority violation on file | FORT LUPTON, Weld, CO | Pass | State |
| 2026-04-03 | MICROSOFT CORPORATION - WILLOW CREEK/GINGER EAST DATA | DES MOINES, Polk, IA | Pending | Local |
| 2026-04-03 | GARFIELD FACILITY LLC — high-priority violation on file | MUNCIE, Delaware, IN | Pass | State |
| 2026-04-03 | GARFIELD FACILITY LLC — high-priority violation on file | MUNCIE, Delaware, IN | Pass | State |
| 2026-04-03 | REWORLD HAVERHILL LLC F.K.A. COVANTA HAVERHILL INCORPORATED | HAVERHILL, TOWN OF, Essex, MA | Pending | State |
| 2026-04-03 | HEARTLAND CORN PRODUCTS | WINTHROP, Sibley, MN | Pass | State |
| 2026-04-03 | MP DURHAM, LLC (LANDFILL GAS-TO-ENERGY PROJECT) | DURHAM, Durham, NC | Pending | State |
| 2026-04-03 | ZIA HILLS CENTRAL FACILITY | MALAGA, Lea, NM | Pass | State |
| 2026-04-02 | ACME BRICK TILE & STONE, INC. | MONTGOMERY, Montgomery, AL | Pass | State |
| 2026-04-02 | EXPLORATORY VENTURES, LLC. | OSCEOLA, Mississippi, AR | Pass | State |
| 2026-04-02 | EXPLORATORY VENTURES, LLC. | OSCEOLA, Mississippi, AR | Pass | State |
| 2026-04-02 | U OF A VETERINARY DIAGNOSTIC LABORATORY | FAYETTEVILLE, Washington, AR | Pass | State |
| 2026-04-02 | FREEPORT-MCMORAN - MORENCI | MORENCI, Greenlee, AZ | Pass | State |
| 2026-04-02 | SALT RIVER PROJECT - SANTAN GENERATING STATION | MARICOPA COUNTY, Maricopa, AZ | Pass | Local |
| 2026-04-02 | PLAINS MARKETING, LP — high-priority violation on file | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-04-02 | PLAINS MARKETING, LP — high-priority violation on file | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-04-02 | PLAINS MARKETING, LP — high-priority violation on file | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-04-02 | PLAINS MARKETING, LP — high-priority violation on file | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-04-02 | PLAINS MARKETING, LP — high-priority violation on file | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-04-02 | AERA ENERGY — high-priority violation on file | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-04-02 | AERA ENERGY — high-priority violation on file | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-04-02 | AERA ENERGY — high-priority violation on file | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-04-02 | AERA ENERGY — high-priority violation on file | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-04-02 | AERA ENERGY — high-priority violation on file | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-04-02 | AERA ENERGY — high-priority violation on file | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-04-02 | AERA ENERGY — high-priority violation on file | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-04-02 | NEW-INDY OXNARD, LLC | OXNARD, Ventura, CA | Pass | Local |
| 2026-04-02 | MILLIKEN & CO. DBA SIVANCE, LLC | GAINESVILLE, Alachua, FL | Pass | State |
| 2026-04-02 | BREVARD CO BOARD OF COUNTY COMMISSIONERS | COCOA, Brevard, FL | Pass | State |
| 2026-04-02 | MIAMI-DADE WATER AND SEWER DEPARTMENT | MIAMI, Miami-Dade, FL | Pass | State |
| 2026-04-02 | MIAMI-DADE WATER AND SEWER DEPARTMENT | MIAMI, Miami-Dade, FL | Pass | State |
| 2026-04-02 | MIAMI-DADE WATER AND SEWER DEPARTMENT | MIAMI, Miami-Dade, FL | Pass | State |
| 2026-04-02 | MIAMI-DADE WATER AND SEWER DEPARTMENT | MIAMI, Miami-Dade, FL | Pass | State |
| 2026-04-02 | INTERNATIONAL PAPER COMPANY | CANTONMENT, Escambia, FL | Pass | State |
| 2026-04-02 | INTERNATIONAL PAPER COMPANY | CANTONMENT, Escambia, FL | Pass | State |
| 2026-04-02 | INTERNATIONAL PAPER COMPANY | CANTONMENT, Escambia, FL | Pass | State |
| 2026-04-02 | INTERNATIONAL PAPER COMPANY | CANTONMENT, Escambia, FL | Pass | State |
| 2026-04-02 | INTERNATIONAL PAPER COMPANY | CANTONMENT, Escambia, FL | Pass | State |
| 2026-04-02 | INTERNATIONAL PAPER COMPANY | CANTONMENT, Escambia, FL | Pass | State |
| 2026-04-02 | INTERNATIONAL PAPER COMPANY | CANTONMENT, Escambia, FL | Pass | State |
| 2026-04-02 | CEMEX SOUTHEAST, LLC | CLINCHFIELD, Houston, GA | Pass | State |
| 2026-04-02 | CEMEX SOUTHEAST, LLC | CLINCHFIELD, Houston, GA | Pass | State |
| 2026-04-02 | CEMEX SOUTHEAST, LLC | CLINCHFIELD, Houston, GA | Pass | State |
| 2026-04-02 | CEMEX SOUTHEAST, LLC | CLINCHFIELD, Houston, GA | Pass | State |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.