EPA Air · stack tests by state and year
Air-emissions stack tests in Illinois, 2026
- 165Stack 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 Illinois 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 Illinois, 2026
- Williamson County 19
- Rock Island County 17
- Montgomery County 15
- Kane County 13
- Macon County 12
- Champaign County 11
- Clark County 11
- Will County 10
- La Salle County 9
- Cook County 6
- Clay County 5
- Madison County 4
- Effingham County 4
- Massac County 4
- Lake County 3
- Christian County 3
Illinois, other years
Air-emissions stack tests recorded in Illinois, 2026
| Date | Facility | Where | Kind | Agency |
|---|---|---|---|---|
| 2026-04-14 | CLARIOS LLC | GENEVA, Kane, IL | Fail | State |
| 2026-04-14 | CLARIOS LLC | GENEVA, Kane, IL | Pass | State |
| 2026-04-14 | CLARIOS LLC | GENEVA, Kane, IL | Pass | State |
| 2026-04-14 | ADVOCATE SHERMAN HOSPITAL | ELGIN, Kane, IL | Pass | State |
| 2026-04-14 | ADVOCATE SHERMAN HOSPITAL | ELGIN, Kane, IL | Pass | State |
| 2026-04-09 | WAYNE CO LANDFILL INC | FAIRFIELD, Wayne, IL | Pending | State |
| 2026-04-02 | HILLSBORO ENERGY LLC | HILLSBORO, Montgomery, IL | Pass | State |
| 2026-04-01 | PEOPLES GAS LIGHT & COKE CO | FISHER, Champaign, IL | Pass | State |
| 2026-04-01 | PEOPLES GAS LIGHT & COKE CO | FISHER, Champaign, IL | Pass | State |
| 2026-04-01 | NICOR GAS | TROY GROVE, La Salle, IL | Pass | State |
| 2026-04-01 | NICOR GAS | TROY GROVE, La Salle, IL | Pass | State |
| 2026-04-01 | NICOR GAS | TROY GROVE, La Salle, IL | Pass | State |
| 2026-04-01 | HILLSBORO ENERGY LLC | HILLSBORO, Montgomery, IL | Pass | State |
| 2026-04-01 | HILLSBORO ENERGY LLC | HILLSBORO, Montgomery, IL | Pass | State |
| 2026-04-01 | HILLSBORO ENERGY LLC | HILLSBORO, Montgomery, IL | Pass | State |
| 2026-04-01 | HILLSBORO ENERGY LLC | HILLSBORO, Montgomery, IL | Pass | State |
| 2026-04-01 | HILLSBORO ENERGY LLC | HILLSBORO, Montgomery, IL | Pass | State |
| 2026-04-01 | HILLSBORO ENERGY LLC | HILLSBORO, Montgomery, IL | Pass | State |
| 2026-04-01 | HILLSBORO ENERGY LLC | HILLSBORO, Montgomery, IL | Pass | State |
| 2026-04-01 | HILLSBORO ENERGY LLC | HILLSBORO, Montgomery, IL | Pass | State |
| 2026-04-01 | HILLSBORO ENERGY LLC | HILLSBORO, Montgomery, IL | Pass | State |
| 2026-04-01 | HILLSBORO ENERGY LLC | HILLSBORO, Montgomery, IL | Pass | State |
| 2026-04-01 | HILLSBORO ENERGY LLC | HILLSBORO, Montgomery, IL | Pass | State |
| 2026-04-01 | HILLSBORO ENERGY LLC | HILLSBORO, Montgomery, IL | Pass | State |
| 2026-04-01 | HILLSBORO ENERGY LLC | HILLSBORO, Montgomery, IL | Pass | State |
| 2026-04-01 | ANR PIPELINE CO | JOLIET, Will, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-04-01 | WILLIAMSON ENERGY LLC | JOHNSTON CITY, Williamson, IL | Pass | State |
| 2026-03-31 | PEOPLES GAS LIGHT & COKE CO | FISHER, Champaign, IL | Pass | State |
| 2026-03-30 | CITGO PETROLEUM CORP — high-priority violation on file | LEMONT, Will, IL | Pass | State |
| 2026-03-30 | EXXONMOBIL OIL CORP | LOCKPORT, Will, IL | Pass | State |
| 2026-03-27 | HOLCIM (US) INC | GRAND CHAIN, Massac, IL | Pass | State |
| 2026-03-26 | ID CASTINGS OF ILLINOIS LLC — high-priority violation on file | MARTINSVILLE, Clark, IL | Pass | State |
| 2026-03-25 | ID CASTINGS OF ILLINOIS LLC — high-priority violation on file | MARTINSVILLE, Clark, IL | Pass | State |
| 2026-03-13 | KINDER MORGAN LIQUIDS TERMINALS LLC | WOOD RIVER, Madison, IL | Pass | State |
| 2026-03-11 | WATERLOO CITY LIGHT PLANT | WATERLOO, Monroe, IL | Pass | State |
| 2026-03-10 | CARMI LIGHT & WATER | CARMI, White, IL | Pass | State |
| 2026-03-05 | SUGAR CAMP ENERGY LLC | MACEDONIA, Franklin, IL | Pass | State |
| 2026-03-05 | EXXON MOBIL OIL CORP — high-priority violation on file | CHANNAHON, Will, IL | Pass | State |
| 2026-03-04 | H KRAMER & CO — high-priority violation on file | CHICAGO, Cook, IL | Pass | State |
| 2026-03-04 | US MINERALS | COFFEEN, Montgomery, IL | Pass | State |
| 2026-03-03 | HOLCIM (US) INC | GRAND CHAIN, Massac, IL | Pass | State |
| 2026-03-03 | HOLCIM (US) INC | GRAND CHAIN, Massac, IL | Pass | State |
| 2026-03-03 | HOLCIM (US) INC | GRAND CHAIN, Massac, IL | Pass | State |
| 2026-02-24 | ADM QUINCY — high-priority violation on file | QUINCY, Adams, IL | Pass | State |
| 2026-02-24 | ADM QUINCY — high-priority violation on file | QUINCY, Adams, IL | Pass | State |
| 2026-02-19 | NATURAL GAS PIPELINE CO OF AMERICA | HERSCHER, Kankakee, IL | Pass | State |
| 2026-02-18 | NATURAL GAS PIPELINE CO OF AMERICA | HERSCHER, Kankakee, IL | Pass | State |
| 2026-02-10 | SOUTHERN ILLINOIS POWER COOP | MARION, Williamson, IL | Pass | State |
| 2026-02-04 | WR GRACE | CHICAGO, Cook, IL | Pass | State |
| 2026-01-20 | HICKORY RIDGE LANDFILL INC | BAYLIS, Pike, IL | Pass | State |
| 2026-01-13 | GUARDIAN PIPELINE CO | CHANNAHON, Will, IL | Pass | State |
| 2026-01-09 | WRB REFINING LP WOOD RIVER REFINERY — high-priority violation on file | ROXANA, Madison, IL | Pass | State |
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Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.