EPA radon zones
Illinois radon map: every county's zone
56 of Illinois's 102 counties are EPA radon zone 1 (predicted average above 4 pCi/L), 43 are zone 2 and 3 are zone 3. High readings occur in every zone, so EPA recommends testing every home.
Adams CountyZone 1
Alexander CountyZone 3
Bond CountyZone 2
Boone CountyZone 1
Brown CountyZone 1
Bureau CountyZone 1
Calhoun CountyZone 1
Carroll CountyZone 1
Cass CountyZone 1
Champaign CountyZone 1
Christian CountyZone 2
Clark CountyZone 2
Clay CountyZone 2
Clinton CountyZone 2
Coles CountyZone 1
Cook CountyZone 2
Crawford CountyZone 2
Cumberland CountyZone 2
De Witt CountyZone 1
DeKalb CountyZone 1
Douglas CountyZone 1
DuPage CountyZone 2
Edgar CountyZone 1
Edwards CountyZone 2
Effingham CountyZone 2
Fayette CountyZone 2
Ford CountyZone 1
Franklin CountyZone 2
Fulton CountyZone 1
Gallatin CountyZone 2
Greene CountyZone 1
Grundy CountyZone 1
Hamilton CountyZone 2
Hancock CountyZone 1
Hardin CountyZone 2
Henderson CountyZone 1
Henry CountyZone 1
Iroquois CountyZone 1
Jackson CountyZone 2
Jasper CountyZone 2
Jefferson CountyZone 2
Jersey CountyZone 1
Jo Daviess CountyZone 1
Johnson CountyZone 2
Kane CountyZone 1
Kankakee CountyZone 2
Kendall CountyZone 1
Knox CountyZone 1
Lake CountyZone 2
LaSalle CountyZone 1
Lawrence CountyZone 2
Lee CountyZone 1
Livingston CountyZone 1
Logan CountyZone 1
Macon CountyZone 1
Macoupin CountyZone 2
Madison CountyZone 2
Marion CountyZone 2
Marshall CountyZone 1
Mason CountyZone 1
Massac CountyZone 3
McDonough CountyZone 1
McHenry CountyZone 2
McLean CountyZone 1
Menard CountyZone 1
Mercer CountyZone 1
Monroe CountyZone 2
Montgomery CountyZone 2
Morgan CountyZone 1
Moultrie CountyZone 1
Ogle CountyZone 1
Peoria CountyZone 1
Perry CountyZone 2
Piatt CountyZone 1
Pike CountyZone 1
Pope CountyZone 2
Pulaski CountyZone 3
Putnam CountyZone 1
Randolph CountyZone 2
Richland CountyZone 2
Rock Island CountyZone 1
Saline CountyZone 2
Sangamon CountyZone 1
Schuyler CountyZone 1
Scott CountyZone 1
Shelby CountyZone 2
St. Clair CountyZone 2
Stark CountyZone 1
Stephenson CountyZone 1
Tazewell CountyZone 1
Union CountyZone 2
Vermilion CountyZone 1
Wabash CountyZone 2
Warren CountyZone 1
Washington CountyZone 2
Wayne CountyZone 2
White CountyZone 2
Whiteside CountyZone 1
Will CountyZone 2
Williamson CountyZone 2
Winnebago CountyZone 1
Woodford CountyZone 1
How much does radon mitigation cost?
Most single-family systems cost $800 to $2,500 installed, depending on foundation type and how many suction points are needed. A follow-up test confirms the system works.
What do the zones mean?
EPA radon zones describe counties, not houses. Zone 1 counties have a predicted average indoor level above 4 picocuries per liter (pCi/L), Zone 2 between 2 and 4, Zone 3 below 2. Homes with high levels are found in every zone, which is why EPA recommends that every home be tested, and fixed at 4 pCi/L or above.
Illinois cities: water and radon
Source: EPA Map of Radon Zones.