Zone 1 Zone 2 Zone 3
WINNE-
BAGO
COOK
ROCK ISLAND
KANKAKEE
STARK
KNOX
IROQUOIS
MCDO-
NOUGH
HANCOCK
SCHUYLER
PIKE
CLARK
JERSEY
CLAY
MONROE
PERRY
JACKSON
http://www.epa.gov/radon/zonemap.html
ILLINOIS - EPA Map of Radon Zones
IMPORTANT: Consult the publication entitled "Preliminary Geologic Radon
Potential Assessment of Illinois" (USGS Open-file Report 93-292-E) before
using this map. http://energy.cr.usgs.gov/radon/grpinfo.html This document
contains information on radon potential variations within counties. EPA also
recommends that this map be supplemented with any available local data in
order to further understand and predict the radon potential of a specific area.
The purpose of this map is to assist National, State and local organizations to target their resources and to
implement radon-resistant building codes.
This map is not intended to determine if a home in a given zone should be tested for radon.
Homes with elevated levels of radon have been found in all three zones.
All homes should be tested, regardless of zone designation.

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