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 |
|---|---|---|---|---|
| 2026-06-30 | TABLE MOUNTAIN - CHAIR COMPRESSOR STATION (PRONGHORN MIDSTREAM LLC) | JOHNSON COUNTY, Johnson, WY | Pass | State |
| 2026-06-30 | TABLE MOUNTAIN - CHAIR COMPRESSOR STATION (PRONGHORN MIDSTREAM LLC) | JOHNSON COUNTY, Johnson, WY | Pass | State |
| 2026-06-30 | TABLE MOUNTAIN - CHAIR COMPRESSOR STATION (PRONGHORN MIDSTREAM LLC) | JOHNSON COUNTY, Johnson, WY | Pass | State |
| 2026-06-26 | NEIL SIMPSON COMPLEX (BLACK HILLS CORPORATION) | GILLETTE, Campbell, WY | Pass | State |
| 2026-06-26 | NEIL SIMPSON COMPLEX (BLACK HILLS CORPORATION) | GILLETTE, Campbell, WY | Pass | State |
| 2026-06-24 | PRCC COMPRESSOR STATION (THUNDER CREEK GAS SERVICES) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-06-24 | PRCC COMPRESSOR STATION (THUNDER CREEK GAS SERVICES) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-06-24 | PRCC COMPRESSOR STATION (THUNDER CREEK GAS SERVICES) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-06-24 | PRCC COMPRESSOR STATION (THUNDER CREEK GAS SERVICES) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-06-24 | CKN-ROCK SPRINGS STATION (MOUNTAIN WEST PIPELINE, LLC) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | CKN-ROCK SPRINGS STATION (MOUNTAIN WEST PIPELINE, LLC) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | CKN-ROCK SPRINGS STATION (MOUNTAIN WEST PIPELINE, LLC) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | CKN-ROCK SPRINGS STATION (MOUNTAIN WEST PIPELINE, LLC) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-24 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-23 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-23 | HANSEN LAKE COMPRESSOR STATION (WILLIAMS FIELD SERVICES CO.) | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-22 | LEAVITT COMPRESSOR STATION (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-06-22 | LEAVITT COMPRESSOR STATION (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-06-22 | LEAVITT COMPRESSOR STATION (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-06-22 | LEAVITT COMPRESSOR STATION (THUNDER CREEK GAS SERVICES) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-06-19 | ECHO SPRINGS GAS PLANT (WILLIAMS FIELD SERVICES) | CARBON COUNTY, Carbon, WY | Pass | State |
| 2026-06-19 | ECHO SPRINGS GAS PLANT (WILLIAMS FIELD SERVICES) | CARBON COUNTY, Carbon, WY | Pass | State |
| 2026-06-19 | ECHO SPRINGS GAS PLANT (WILLIAMS FIELD SERVICES) | CARBON COUNTY, Carbon, WY | Pass | State |
| 2026-06-19 | ECHO SPRINGS GAS PLANT (WILLIAMS FIELD SERVICES) | CARBON COUNTY, Carbon, WY | Pass | State |
| 2026-06-19 | ECHO SPRINGS GAS PLANT (WILLIAMS FIELD SERVICES) | CARBON COUNTY, Carbon, WY | Pass | State |
| 2026-06-19 | ECHO SPRINGS GAS PLANT (WILLIAMS FIELD SERVICES) | CARBON COUNTY, Carbon, WY | Pass | State |
| 2026-06-18 | ECHO SPRINGS GAS PLANT (WILLIAMS FIELD SERVICES) | CARBON COUNTY, Carbon, WY | Pass | State |
| 2026-06-18 | ECHO SPRINGS GAS PLANT (WILLIAMS FIELD SERVICES) | CARBON COUNTY, Carbon, WY | Pass | State |
| 2026-06-18 | ECHO SPRINGS GAS PLANT (WILLIAMS FIELD SERVICES) | CARBON COUNTY, Carbon, WY | Pass | State |
| 2026-06-18 | ECHO SPRINGS GAS PLANT (WILLIAMS FIELD SERVICES) | CARBON COUNTY, Carbon, WY | Pass | State |
| 2026-06-18 | ECHO SPRINGS GAS PLANT (WILLIAMS FIELD SERVICES) | CARBON COUNTY, Carbon, WY | Pass | State |
| 2026-06-18 | PAINTER COMPRESSOR STATION (KERN RIVER GAS TRANSMISSION) | EVANSTON, Uinta, WY | Pass | State |
| 2026-06-18 | PAINTER COMPRESSOR STATION (KERN RIVER GAS TRANSMISSION) | EVANSTON, Uinta, WY | Pass | State |
| 2026-06-17 | TABLE MOUNTAIN - CHAIR COMPRESSOR STATION (PRONGHORN MIDSTREAM LLC) | JOHNSON COUNTY, Johnson, WY | Pass | State |
| 2026-06-17 | TABLE MOUNTAIN - CHAIR COMPRESSOR STATION (PRONGHORN MIDSTREAM LLC) | JOHNSON COUNTY, Johnson, WY | Pass | State |
| 2026-06-17 | TABLE MOUNTAIN - CHAIR COMPRESSOR STATION (PRONGHORN MIDSTREAM LLC) | JOHNSON COUNTY, Johnson, WY | Pass | State |
| 2026-06-17 | OPAL GAS PLANT (WILLIAMS FIELD SERVICES) | OPAL, Lincoln, WY | Pass | State |
| 2026-06-17 | OPAL GAS PLANT (WILLIAMS FIELD SERVICES) | OPAL, Lincoln, WY | Pass | State |
| 2026-06-17 | OPAL GAS PLANT (WILLIAMS FIELD SERVICES) | OPAL, Lincoln, WY | Pass | State |
| 2026-06-17 | MUDDY CREEK STATION (KERN RIVER GAS TRANS) | LINCOLN COUNTY, Lincoln, WY | Pass | State |
| 2026-06-17 | MUDDY CREEK STATION (KERN RIVER GAS TRANS) | LINCOLN COUNTY, Lincoln, WY | Pass | State |
| 2026-06-16 | OPAL GAS PLANT (WILLIAMS FIELD SERVICES) | OPAL, Lincoln, WY | Pass | State |
| 2026-06-16 | OPAL GAS PLANT (WILLIAMS FIELD SERVICES) | OPAL, Lincoln, WY | Pass | State |
| 2026-06-16 | OPAL GAS PLANT (WILLIAMS FIELD SERVICES) | OPAL, Lincoln, WY | Pass | State |
| 2026-06-16 | MUDDY CREEK STATION (KERN RIVER GAS TRANS) | LINCOLN COUNTY, Lincoln, WY | Pass | State |
| 2026-06-16 | MUDDY CREEK STATION (KERN RIVER GAS TRANS) | LINCOLN COUNTY, Lincoln, WY | Pass | State |
| 2026-06-12 | MORGAN DRAW/CRENSHAW HILL (PRONGHORN MIDSTREAM LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-06-12 | MORGAN DRAW/CRENSHAW HILL (PRONGHORN MIDSTREAM LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-06-12 | MORGAN DRAW/CRENSHAW HILL (PRONGHORN MIDSTREAM LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-06-11 | BIG ISLAND MINE & REFINERY (SISECAM WYOMING LLC) — high-priority violation on file | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-11 | BIG ISLAND MINE & REFINERY (SISECAM WYOMING LLC) — high-priority violation on file | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-11 | BIG ISLAND MINE & REFINERY (SISECAM WYOMING LLC) — high-priority violation on file | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-11 | BIG ISLAND MINE & REFINERY (SISECAM WYOMING LLC) — high-priority violation on file | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-11 | BIG ISLAND MINE & REFINERY (SISECAM WYOMING LLC) — high-priority violation on file | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-11 | BIG ISLAND MINE & REFINERY (SISECAM WYOMING LLC) — high-priority violation on file | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-11 | BIG ISLAND MINE & REFINERY (SISECAM WYOMING LLC) — high-priority violation on file | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-11 | BIG ISLAND MINE & REFINERY (SISECAM WYOMING LLC) — high-priority violation on file | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-11 | BIG ISLAND MINE & REFINERY (SISECAM WYOMING LLC) — high-priority violation on file | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-11 | BIG ISLAND MINE & REFINERY (SISECAM WYOMING LLC) — high-priority violation on file | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-11 | BIG ISLAND MINE & REFINERY (SISECAM WYOMING LLC) — high-priority violation on file | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-11 | BIG ISLAND MINE & REFINERY (SISECAM WYOMING LLC) — high-priority violation on file | SWEETWATER COUNTY, Sweetwater, WY | Pass | State |
| 2026-06-11 | ROCK SPRINGS FERTILIZER COMPLEX (SIMPLOT PHOSPHATES) | ROCK SPRINGS, Sweetwater, WY | Pass | State |
| 2026-06-11 | ROCK SPRINGS FERTILIZER COMPLEX (SIMPLOT PHOSPHATES) | ROCK SPRINGS, Sweetwater, WY | Pass | State |
| 2026-06-10 | MORGAN DRAW/CRENSHAW HILL (PRONGHORN MIDSTREAM LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-06-10 | MORGAN DRAW/CRENSHAW HILL (PRONGHORN MIDSTREAM LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-06-10 | MORGAN DRAW/CRENSHAW HILL (PRONGHORN MIDSTREAM LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-06-10 | MORGAN DRAW/CRENSHAW HILL (PRONGHORN MIDSTREAM LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-06-10 | MORGAN DRAW/CRENSHAW HILL (PRONGHORN MIDSTREAM LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-06-10 | MORGAN DRAW/CRENSHAW HILL (PRONGHORN MIDSTREAM LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-06-10 | ROCK SPRINGS FERTILIZER COMPLEX (SIMPLOT PHOSPHATES) | ROCK SPRINGS, Sweetwater, WY | Pass | State |
| 2026-06-10 | ROCK SPRINGS FERTILIZER COMPLEX (SIMPLOT PHOSPHATES) | ROCK SPRINGS, Sweetwater, WY | Pass | State |
| 2026-06-09 | MORGAN DRAW/CRENSHAW HILL (PRONGHORN MIDSTREAM LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-06-09 | MORGAN DRAW/CRENSHAW HILL (PRONGHORN MIDSTREAM LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-06-09 | MORGAN DRAW/CRENSHAW HILL (PRONGHORN MIDSTREAM LLC) | CAMPBELL COUNTY, Campbell, WY | Pass | State |
| 2026-06-09 | ROCK SPRINGS FERTILIZER COMPLEX (SIMPLOT PHOSPHATES) | ROCK SPRINGS, Sweetwater, WY | Pass | State |
| 2026-06-09 | ROCK SPRINGS FERTILIZER COMPLEX (SIMPLOT PHOSPHATES) | ROCK SPRINGS, Sweetwater, WY | Pass | State |
| 2026-06-08 | BUCKING HORSE PLANT (JACKALOPE GAS GATHERING) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-06-08 | BUCKING HORSE PLANT (JACKALOPE GAS GATHERING) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-06-08 | BUCKING HORSE PLANT (JACKALOPE GAS GATHERING) | CONVERSE COUNTY, Converse, WY | Pass | State |
| 2026-06-04 | OPAL GAS PLANT (WILLIAMS FIELD SERVICES) | OPAL, Lincoln, WY | Pass | State |
| 2026-06-04 | OPAL GAS PLANT (WILLIAMS FIELD SERVICES) | OPAL, Lincoln, WY | Pass | State |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.