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 |
|---|---|---|---|---|
| 2026-01-14 | MIDCONTINENT EXPRESS PIPELINE LLC, MEP 4 VICKSBURG COMPRESSOR STATION | EDWARDS, Hinds, MS | Pass | State |
| 2026-01-14 | MIDCONTINENT EXPRESS PIPELINE LLC, MEP 4 VICKSBURG COMPRESSOR STATION | EDWARDS, Hinds, MS | Pass | State |
| 2026-01-14 | MIDCONTINENT EXPRESS PIPELINE LLC, MEP 4 VICKSBURG COMPRESSOR STATION | EDWARDS, Hinds, MS | Pass | State |
| 2026-01-14 | GULF SOUTH PIPELINE COMPANY LLC, HARRISVILLE COMPRESSOR STATION | HARRISVILLE, Simpson, MS | Pass | State |
| 2026-01-14 | GULF SOUTH PIPELINE COMPANY LLC, HARRISVILLE COMPRESSOR STATION | HARRISVILLE, Simpson, MS | Pass | State |
| 2026-01-14 | GULF SOUTH PIPELINE COMPANY LLC, HARRISVILLE COMPRESSOR STATION | HARRISVILLE, Simpson, MS | Pass | State |
| 2026-01-14 | GULF SOUTH PIPELINE COMPANY LLC, HARRISVILLE COMPRESSOR STATION | HARRISVILLE, Simpson, MS | Pass | State |
| 2026-01-14 | GULF SOUTH PIPELINE COMPANY LLC, HARRISVILLE COMPRESSOR STATION | HARRISVILLE, Simpson, MS | Pass | State |
| 2026-01-14 | GULF SOUTH PIPELINE COMPANY LLC, HARRISVILLE COMPRESSOR STATION | HARRISVILLE, Simpson, MS | Pass | State |
| 2026-01-14 | GULF SOUTH PIPELINE COMPANY LLC, HARRISVILLE COMPRESSOR STATION | HARRISVILLE, Simpson, MS | Pass | State |
| 2026-01-14 | GULF SOUTH PIPELINE COMPANY LLC, HARRISVILLE COMPRESSOR STATION | HARRISVILLE, Simpson, MS | Pass | State |
| 2026-01-14 | LEAF RIVER ENERGY CENTER LLC, LEAF RIVER ENERGY CENTER | TAYLORSVILLE, Smith, MS | Pass | State |
| 2026-01-14 | LEAF RIVER ENERGY CENTER LLC, LEAF RIVER ENERGY CENTER | TAYLORSVILLE, Smith, MS | Pass | State |
| 2026-01-14 | LEAF RIVER ENERGY CENTER LLC, LEAF RIVER ENERGY CENTER | TAYLORSVILLE, Smith, MS | Pass | State |
| 2026-01-14 | LEAF RIVER ENERGY CENTER LLC, LEAF RIVER ENERGY CENTER | TAYLORSVILLE, Smith, MS | Pass | State |
| 2026-01-14 | CLARIOS | KERNERSVILLE, Forsyth, NC | Pass | Local |
| 2026-01-14 | CLARIOS | KERNERSVILLE, Forsyth, NC | Pass | Local |
| 2026-01-14 | CLARIOS | KERNERSVILLE, Forsyth, NC | Pass | Local |
| 2026-01-14 | NORTHERN NATURAL GAS COMPANY | BEATRICE, Gage, NE | Pass | State |
| 2026-01-14 | CARGILL INC — high-priority violation on file | BLAIR, Washington, NE | Pass | State |
| 2026-01-14 | CARGILL INC — high-priority violation on file | BLAIR, Washington, NE | Pass | State |
| 2026-01-14 | OXY SAND DUNES SOUTH COMPRESSOR STATION | MALAGA, Eddy, NM | Pass | State |
| 2026-01-14 | CAVERN COMPRESSOR STATION | WHITES CITY, Eddy, NM | Pass | State |
| 2026-01-14 | CAVERN COMPRESSOR STATION | WHITES CITY, Eddy, NM | Pass | State |
| 2026-01-14 | 3 BEAR LIBBY GAS PLANT | MONUMENT, Lea, NM | Pass | State |
| 2026-01-14 | 3 BEAR LIBBY GAS PLANT | MONUMENT, Lea, NM | Pass | State |
| 2026-01-14 | POET BIOREFINING - MARION, LLC | MARION, Marion, OH | Pass | State |
| 2026-01-14 | POET BIOREFINING - MARION, LLC | MARION, Marion, OH | Pass | State |
| 2026-01-14 | POET BIOREFINING - MARION, LLC | MARION, Marion, OH | Pass | State |
| 2026-01-14 | POET BIOREFINING - MARION, LLC | MARION, Marion, OH | Pass | State |
| 2026-01-14 | POET BIOREFINING - MARION, LLC | MARION, Marion, OH | Pass | State |
| 2026-01-14 | EQM OLYMPUS MIDSTREAM LLC - BIG KAHUNA CS | BELMONT, Belmont, OH | Pass | State |
| 2026-01-14 | EQM OLYMPUS MIDSTREAM LLC - BIG KAHUNA CS | BELMONT, Belmont, OH | Pass | State |
| 2026-01-14 | EQM OLYMPUS MIDSTREAM LLC - BIG KAHUNA CS | BELMONT, Belmont, OH | Pass | State |
| 2026-01-14 | EQM OLYMPUS MIDSTREAM LLC - BIG KAHUNA CS | BELMONT, Belmont, OH | Pass | State |
| 2026-01-14 | EQM OLYMPUS MIDSTREAM LLC - BIG KAHUNA CS | BELMONT, Belmont, OH | Pass | State |
| 2026-01-14 | EQM OLYMPUS MIDSTREAM LLC - BIG KAHUNA CS | BELMONT, Belmont, OH | Pass | State |
| 2026-01-14 | EQM OLYMPUS MIDSTREAM LLC - BIG KAHUNA CS | BELMONT, Belmont, OH | Pass | State |
| 2026-01-14 | EQM OLYMPUS MIDSTREAM LLC - BIG KAHUNA CS | BELMONT, Belmont, OH | Pass | State |
| 2026-01-14 | EQM OLYMPUS MIDSTREAM LLC - BIG KAHUNA CS | BELMONT, Belmont, OH | Pass | State |
| 2026-01-14 | EQM OLYMPUS MIDSTREAM LLC - BIG KAHUNA CS | BELMONT, Belmont, OH | Pass | State |
| 2026-01-14 | EQM OLYMPUS MIDSTREAM LLC - BIG KAHUNA CS | BELMONT, Belmont, OH | Pass | State |
| 2026-01-14 | EQM OLYMPUS MIDSTREAM LLC - BIG KAHUNA CS | BELMONT, Belmont, OH | Pass | State |
| 2026-01-14 | CRAIG MILLER PAD 952413 | BEALLSVILLE, Monroe, OH | Pass | State |
| 2026-01-14 | CRAIG MILLER PAD 952413 | BEALLSVILLE, Monroe, OH | Pass | State |
| 2026-01-14 | CRAIG MILLER PAD 952413 | BEALLSVILLE, Monroe, OH | Pass | State |
| 2026-01-14 | COLUMBIA GAS TRANS CORP/HELLERTOWN CT | HELLERTOWN, Northampton, PA | Pass | State |
| 2026-01-14 | APPALACHIA MIDSTREAM SVC LLC/AUBURN COMP STA | MESHOPPEN, Susquehanna, PA | Pass | State |
| 2026-01-14 | GREYLOCK PROD LLC/ANSONVILLE COMP STA | NEW MILLPORT, Clearfield, PA | Pass | State |
| 2026-01-14 | HEP PENNSYLVANIA GATHERING LLC/LAUREL HILL COMP STA | TROUT RUN, Lycoming, PA | Pass | State |
| 2026-01-14 | HEP PENNSYLVANIA GATHERING LLC/LAUREL HILL COMP STA | TROUT RUN, Lycoming, PA | Pass | State |
| 2026-01-14 | HEP PENNSYLVANIA GATHERING LLC/TIOGA CPF#2 COMP STA | LIBERTY, Tioga, PA | Pass | State |
| 2026-01-14 | CAROLINA GAS TRANSMISSION LLC - SOUTHERN COMPRESSOR STATION | WARRENVILLE, Aiken, SC | Pending | State |
| 2026-01-14 | ELEMENT MATERIALS TECHNOLOGY — high-priority violation on file | PIEDMONT, Anderson, SC | Fail | State |
| 2026-01-14 | NUCOR STEEL - BERKELEY | HUGER, Berkeley, SC | Pass | State |
| 2026-01-14 | SANTEE COOPER WINYAH GENERATING STATION | GEORGETOWN, Georgetown, SC | Pass | State |
| 2026-01-14 | GEORGETOWN COUNTY SOLID WASTE FACILITY | GEORGETOWN, Georgetown, SC | Pass | State |
| 2026-01-14 | GODLEY PLANT | GODLEY, Johnson, TX | Pass | State |
| 2026-01-14 | UNIVERSITY OF UTAH | SALT LAKE CITY, Salt Lake, UT | Pass | State |
| 2026-01-14 | ROANOKE CEMENT COMPANY | TROUTVILLE, Botetourt, VA | Pass | State |
| 2026-01-14 | PACKAGING CORPORATION OF AMERICA — high-priority violation on file | WALLULA, Walla Walla, WA | Pending | State |
| 2026-01-14 | TABLE MOUNTAIN - CHAIR COMPRESSOR STATION (PRONGHORN MIDSTREAM LLC) | JOHNSON COUNTY, Johnson, WY | Pass | State |
| 2026-01-14 | TABLE MOUNTAIN - CHAIR COMPRESSOR STATION (PRONGHORN MIDSTREAM LLC) | JOHNSON COUNTY, Johnson, WY | Pass | State |
| 2026-01-14 | TABLE MOUNTAIN - CHAIR COMPRESSOR STATION (PRONGHORN MIDSTREAM LLC) | JOHNSON COUNTY, Johnson, WY | Pass | State |
| 2026-01-13 | GOLDEN VALLEY ELECTRIC ASSOCIATION / HEALY POWER PLANT — high-priority violation on file | HEALY, Denali, AK | Pass | State |
| 2026-01-13 | MURPHY OIL USA INC | SHEFFIELD, Colbert, AL | Pass | State |
| 2026-01-13 | HENRY BRICK COMPANY, INC. | SELMA, Dallas, AL | Pass | State |
| 2026-01-13 | ALABAMA POWER COMPANY (MILLER POWER PLANT) | QUINTON, Jefferson, AL | Pass | Local |
| 2026-01-13 | AMERICAN CAST IRON PIPE COMPANY | BIRMINGHAM, Jefferson, AL | Pass | Local |
| 2026-01-13 | DESOTO GATHERING COMPANY, LLC - SOUTHEAST RAINBOW CPF-2 | BEE BRANCH, Conway, AR | Pass | State |
| 2026-01-13 | BLACK HILLS ENERGY ARKANSAS, INC. - SELLS COMPRESSOR STATION | OZARK, Franklin, AR | Pass | State |
| 2026-01-13 | BLACK HILLS ENERGY ARKANSAS, INC. - SELLS COMPRESSOR STATION | OZARK, Franklin, AR | Pass | State |
| 2026-01-13 | BLACK HILLS ENERGY ARKANSAS, INC. - SELLS COMPRESSOR STATION | OZARK, Franklin, AR | Pass | State |
| 2026-01-13 | BLACK HILLS ENERGY ARKANSAS, INC. - SELLS COMPRESSOR STATION | OZARK, Franklin, AR | Pass | State |
| 2026-01-13 | BLACK HILLS ENERGY ARKANSAS, INC. - SELLS COMPRESSOR STATION | OZARK, Franklin, AR | Pass | State |
| 2026-01-13 | BLACK HILLS ENERGY ARKANSAS, INC. - SELLS COMPRESSOR STATION | OZARK, Franklin, AR | Pass | State |
| 2026-01-13 | ENTERGY ARKANSAS, LLC - WHITE BLUFF PLANT | REDFIELD, Jefferson, AR | Pass | State |
| 2026-01-13 | DESOTO GATHERING COMPANY, LLC - STEELHEAD CPF-2 | CLINTON, Van Buren, AR | Pass | State |
| 2026-01-13 | CRESTWOOD WEST COAST LLC | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-01-13 | CRESTWOOD WEST COAST LLC | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-01-13 | CRESTWOOD WEST COAST LLC | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-01-13 | CRESTWOOD WEST COAST LLC | BAKERSFIELD, Kern, CA | Pass | Local |
| 2026-01-13 | DC WATER (BLUE PLAINS WASTEWATER TREATMENT FACILITY) — high-priority violation on file | WASHINGTON, District of Columbia, DC | Fail | State |
| 2026-01-13 | AMRIZE BUILDING ENVELOPE LLC | JACKSONVILLE, Duval, FL | Pass | State |
| 2026-01-13 | ENVIROFOCUS TECHNOLOGIES DBA GOPHER RESO — high-priority violation on file | TAMPA, Hillsborough, FL | Pass | State |
| 2026-01-13 | ENVIROFOCUS TECHNOLOGIES DBA GOPHER RESO — high-priority violation on file | TAMPA, Hillsborough, FL | Pass | State |
| 2026-01-13 | ENVIROFOCUS TECHNOLOGIES DBA GOPHER RESO — high-priority violation on file | TAMPA, Hillsborough, FL | Pass | State |
| 2026-01-13 | ENVIROFOCUS TECHNOLOGIES DBA GOPHER RESO — high-priority violation on file | TAMPA, Hillsborough, FL | Pass | State |
| 2026-01-13 | ENVIROFOCUS TECHNOLOGIES DBA GOPHER RESO — high-priority violation on file | TAMPA, Hillsborough, FL | Pass | State |
| 2026-01-13 | ENVIROFOCUS TECHNOLOGIES DBA GOPHER RESO — high-priority violation on file | TAMPA, Hillsborough, FL | Pass | State |
| 2026-01-13 | ENVIROFOCUS TECHNOLOGIES DBA GOPHER RESO — high-priority violation on file | TAMPA, Hillsborough, FL | Pass | State |
| 2026-01-13 | MOSAIC FERTILIZER LLC — high-priority violation on file | MULBERRY, Polk, FL | Pass | State |
| 2026-01-13 | AMCOR TOBACCO PACKAGING AMERICAS, INC. | PEACHTREE CITY, Fayette, GA | Pass | State |
| 2026-01-13 | PAR - REFINERY — high-priority violation on file | KAPOLEI, Honolulu, HI | Pass | State |
| 2026-01-13 | LSCP LP DBA LITTLE SIOUX CORN PROCESSORS — high-priority violation on file | MARCUS, Cherokee, IA | Fail | State |
| 2026-01-13 | POET BIOREFINING - MENLO, LLC | MENLO, Guthrie, IA | Pass | State |
| 2026-01-13 | GUARDIAN PIPELINE CO | CHANNAHON, Will, IL | Pass | State |
| 2026-01-13 | EDCOAT LLC | NEW CARLISLE, St. Joseph, IN | Pass | State |
| 2026-01-13 | EVERGY, INC. - JEFFREY ENERGY CENTER (AIR) | ST. MARY'S, Pottawatomie, KS | Pass | State |
| 2026-01-13 | CENTURY ALUMINUM SEBREE LLC | ROBARDS, Henderson, KY | Pass | State |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.