EPA Air · stack tests by state and year
Air-emissions stack tests in Wyoming, 2026
- 755Stack tests
A stack test measures what a source actually emits, at the stack, against the limit in its permit. Every stack test below was recorded against a source in Wyoming during 2026; one facility can appear more than once, because this is a record of what happened rather than a list of places.
Counties in Wyoming, 2026
- Campbell County 255
- Sweetwater County 129
- Sublette County 110
- Converse County 92
- Carbon County 58
- Johnson County 33
- Laramie County 19
- Lincoln County 18
- Albany County 17
- Uinta County 6
- Platte County 5
- Crook County 4
- Fremont County 4
- Big Horn County 4
Wyoming, other years
Air-emissions stack tests recorded in Wyoming, 2026
| Date | Facility | Where | Kind | Agency |
|---|---|---|---|---|
| 2026-04-08 | AUGUSTA-PEBBLE BEACH COMPRESSOR STATION (PRONGHORN MIDSTREAM LLC) | JOHNSON COUNTY, Johnson, WY | Pass | State |
| 2026-04-08 | AUGUSTA-PEBBLE BEACH COMPRESSOR STATION (PRONGHORN MIDSTREAM LLC) | JOHNSON COUNTY, Johnson, WY | Pass | State |
| 2026-04-08 | 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 | 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 |
| 2026-04-02 | LOST CABIN GAS PLANT (CONTANGO RESOURCES, LLC.) — high-priority violation on file | LOST CABIN, Fremont, WY | Pass | State |
| 2026-04-02 | GREEN RIVER SODA ASH PLANT (AMERICAN SODA LLC) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-04-02 | GREEN RIVER SODA ASH PLANT (AMERICAN SODA LLC) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-04-01 | MARY'S DRAW (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-04-01 | MARY'S DRAW (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-04-01 | MARY'S DRAW (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-04-01 | MARY'S DRAW (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-04-01 | MARY'S DRAW (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-04-01 | MARY'S DRAW (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-04-01 | MARY'S DRAW (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-04-01 | MARY'S DRAW (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-04-01 | LOST CABIN GAS PLANT (CONTANGO RESOURCES, LLC.) — high-priority violation on file | LOST CABIN, Fremont, WY | Pass | State |
| 2026-04-01 | LOST CABIN GAS PLANT (CONTANGO RESOURCES, LLC.) — high-priority violation on file | LOST CABIN, Fremont, WY | Pass | State |
| 2026-04-01 | LOST CABIN GAS PLANT (CONTANGO RESOURCES, LLC.) — high-priority violation on file | LOST CABIN, Fremont, WY | Pass | State |
| 2026-03-31 | LARAMIE RIVER STATION (BASIN ELECTRIC POWER COOPERATIVE) — high-priority violation on file | WHEATLAND, Platte, WY | Pass | State |
| 2026-03-31 | GREEN RIVER SODA ASH PLANT (AMERICAN SODA LLC) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-03-31 | GREEN RIVER SODA ASH PLANT (AMERICAN SODA LLC) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-03-31 | GREEN RIVER SODA ASH PLANT (AMERICAN SODA LLC) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-03-26 | NEIL SIMPSON COMPLEX (BLACK HILLS CORPORATION) | GILLETTE, Campbell, WY | Pass | State |
| 2026-03-26 | NEIL SIMPSON COMPLEX (BLACK HILLS CORPORATION) | GILLETTE, Campbell, WY | Pass | State |
| 2026-03-25 | MEADOWLARK COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-03-25 | MEADOWLARK COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-03-25 | MEADOWLARK COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-03-25 | MEADOWLARK COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-03-25 | MEADOWLARK COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-03-25 | MEADOWLARK COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-03-25 | MEADOWLARK COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-03-25 | MEADOWLARK COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-03-25 | MEADOWLARK COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-03-25 | MEADOWLARK COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-03-25 | MEADOWLARK COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-03-25 | MEADOWLARK COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-03-25 | SCOTT COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-03-25 | SCOTT COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-03-25 | SCOTT COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-03-25 | SCOTT COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-03-25 | SCOTT COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-03-25 | SCOTT COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-03-25 | SCOTT COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-03-25 | SCOTT COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-03-25 | SCOTT COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-03-25 | SCOTT COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-03-25 | SCOTT COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-03-25 | SCOTT COMPRESSOR STATION (TALLGRASS MIDSTREAM, LLC) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-03-24 | ECHO SPRINGS GAS PLANT (WILLIAMS FIELD SERVICES) | CARBON COUNTY, Carbon, WY | Pass | State |
| 2026-03-24 | ECHO SPRINGS GAS PLANT (WILLIAMS FIELD SERVICES) | CARBON COUNTY, Carbon, WY | Pass | State |
| 2026-03-24 | BRIDGER COMPRESSOR STATION (ENTERPIRSE JONAH GAS GATHERING) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2026-03-24 | BRIDGER COMPRESSOR STATION (ENTERPIRSE JONAH GAS GATHERING) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2026-03-24 | BRIDGER COMPRESSOR STATION (ENTERPIRSE JONAH GAS GATHERING) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2026-03-20 | FONTENELLE STATION (MOUNTAIN GAS RESOURCES LLC) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-03-20 | FONTENELLE STATION (MOUNTAIN GAS RESOURCES LLC) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-03-20 | FONTENELLE STATION (MOUNTAIN GAS RESOURCES LLC) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-03-19 | ROCK SPRINGS FERTILIZER COMPLEX (SIMPLOT PHOSPHATES) | ROCK SPRINGS, Sweetwater, WY | Pass | State |
| 2026-03-18 | ROCK SPRINGS FERTILIZER COMPLEX (SIMPLOT PHOSPHATES) | ROCK SPRINGS, Sweetwater, WY | Pass | State |
| 2026-03-17 | CHEYENNE RENEWABLE DIESEL COMPANY (CHEYENNE RENEWABLE DIESEL COMPANY LLC) | CHEYENNE, Laramie, WY | Pass | State |
| 2026-03-17 | CHEYENNE RENEWABLE DIESEL COMPANY (CHEYENNE RENEWABLE DIESEL COMPANY LLC) | CHEYENNE, Laramie, WY | Pass | State |
| 2026-03-17 | CHEYENNE RENEWABLE DIESEL COMPANY (CHEYENNE RENEWABLE DIESEL COMPANY LLC) | CHEYENNE, Laramie, WY | Pass | State |
| 2026-03-17 | CHEYENNE RENEWABLE DIESEL COMPANY (CHEYENNE RENEWABLE DIESEL COMPANY LLC) | CHEYENNE, Laramie, WY | Pass | State |
| 2026-03-17 | CHEYENNE RENEWABLE DIESEL COMPANY (CHEYENNE RENEWABLE DIESEL COMPANY LLC) | CHEYENNE, Laramie, WY | Pass | State |
| 2026-03-17 | CHEYENNE RENEWABLE DIESEL COMPANY (CHEYENNE RENEWABLE DIESEL COMPANY LLC) | CHEYENNE, Laramie, WY | Pass | State |
| 2026-03-17 | CHEYENNE RENEWABLE DIESEL COMPANY (CHEYENNE RENEWABLE DIESEL COMPANY LLC) | CHEYENNE, Laramie, WY | Pass | State |
| 2026-03-17 | CHEYENNE RENEWABLE DIESEL COMPANY (CHEYENNE RENEWABLE DIESEL COMPANY LLC) | CHEYENNE, Laramie, WY | Pass | State |
| 2026-03-12 | PINEDALE COMPLEX (HARVEST MIDSTREAM COMPANY) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2026-03-12 | PINEDALE COMPLEX (HARVEST MIDSTREAM COMPANY) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2026-03-12 | PINEDALE COMPLEX (HARVEST MIDSTREAM COMPANY) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2026-03-12 | PINEDALE COMPLEX (HARVEST MIDSTREAM COMPANY) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2026-03-12 | PINEDALE COMPLEX (HARVEST MIDSTREAM COMPANY) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2026-03-12 | PINEDALE COMPLEX (HARVEST MIDSTREAM COMPANY) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2026-03-12 | PINEDALE COMPLEX (HARVEST MIDSTREAM COMPANY) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2026-03-12 | PINEDALE COMPLEX (HARVEST MIDSTREAM COMPANY) | SUBLETTE COUNTY, Sublette, WY | Pass | State |
| 2026-03-11 | MORGAN DRAW/CRENSHAW HILL (PRONGHORN MIDSTREAM LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-03-11 | MORGAN DRAW/CRENSHAW HILL (PRONGHORN MIDSTREAM LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-03-11 | LARAMIE RIVER STATION (BASIN ELECTRIC POWER COOPERATIVE) — high-priority violation on file | WHEATLAND, Platte, WY | Pass | State |
| 2026-03-11 | LARAMIE RIVER STATION (BASIN ELECTRIC POWER COOPERATIVE) — high-priority violation on file | WHEATLAND, Platte, WY | Pass | State |
| 2026-03-11 | LARAMIE RIVER STATION (BASIN ELECTRIC POWER COOPERATIVE) — high-priority violation on file | WHEATLAND, Platte, WY | Pass | State |
| 2026-03-11 | LARAMIE RIVER STATION (BASIN ELECTRIC POWER COOPERATIVE) — high-priority violation on file | WHEATLAND, Platte, WY | Pass | State |
| 2026-03-05 | GREYBULL PLANT (WYO-BEN, INC.) | GREYBULL, Big Horn, WY | Pass | State |
| 2026-03-05 | GREYBULL PLANT (WYO-BEN, INC.) | GREYBULL, Big Horn, WY | Pass | State |
| 2026-03-05 | GREYBULL PLANT (WYO-BEN, INC.) | GREYBULL, Big Horn, WY | Pass | State |
| 2026-03-05 | GREYBULL PLANT (WYO-BEN, INC.) | GREYBULL, Big Horn, WY | Pass | State |
| 2026-03-05 | HILIGHT GAS PLANT (WES POWDER RIVER HOLDINGS LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-03-05 | HILIGHT GAS PLANT (WES POWDER RIVER HOLDINGS LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-03-05 | HILIGHT GAS PLANT (WES POWDER RIVER HOLDINGS LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-03-05 | HF SINCLAIR PARCO REFINING LLC — high-priority violation on file | SINCLAIR, Carbon, WY | Pass | State |
| 2026-03-05 | HF SINCLAIR PARCO REFINING LLC — high-priority violation on file | SINCLAIR, Carbon, WY | Pass | State |
| 2026-03-05 | HF SINCLAIR PARCO REFINING LLC — high-priority violation on file | SINCLAIR, Carbon, WY | Pass | State |
| 2026-03-05 | HF SINCLAIR PARCO REFINING LLC — high-priority violation on file | SINCLAIR, Carbon, WY | Pass | State |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.