EPA Air · stack tests by county and year

Air-emissions stack tests in Clay County, Illinois, 2026

• 5Stack tests

A stack test measures what a source actually emits, at the stack, against the limit in its permit. Each row below is one stack test recorded against a source in Clay County, Illinois during 2026. A facility can appear several times: this is the year’s record of what happened, not a list of places. The sources themselves are on the Clay County facility page.

Air-emissions stack tests in Clay County, other years

• 2020 3

Air-emissions stack tests recorded in Clay County, Illinois, 2026

Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.

What this page shows

This page covers Clean Air Act facilities in the EPA air register with stack tests in Clay county, IL, in 2026. Stack tests recorded in 2026: 5.