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Radon in Green Lake County, Wisconsin

Green Lake County, Wisconsin, is in EPA radon Zone 1: predicted average indoor radon screening level greater than 4 pCi/L (highest potential). Radon laboratories reported 124 building tests here for 2008 to 2017: median 4.5 pCi/L, with 53.6% at or above EPA's 4 pCi/L action level (Wisconsin 47%, US 36.5%).

Zone 1
EPA radon zone (1993 county map)
4.5
median lab test, pCi/L (2008-2017)
53.6%
of lab tests at or above 4 pCi/L
124
buildings tested by labs, 2008-2017

Radon test results in Green Lake County

Radon test results on file for Green Lake County, WI, with state and national comparison
Test resultsPeriodTestsTypical result4 pCi/L or more
Radon testing laboratories2008-2017124median 4.5 pCi/L53.6%
Wisconsin radon program202360median 3.4 pCi/L40.5%
Wisconsin, all counties (labs)2008-201755,359n/a47%
United States (labs)2008-20171,408,802n/a36.5%

Test results describe buildings whose owners chose to test and whose results reached the lab or agency, not a random sample; small counts swing widely. State and US shares are computed from county counts and percents. The laboratory data comes from national radon testing laboratories and supplements EPA's zone map.

Radon in nearby counties

CountyEPA zoneLab tests4 pCi/L or more
Marquette County, WIZone 211014.2%
Fond du Lac County, WIZone 197056.4%
Winnebago County, WIZone 21,73756.4%
Waushara County, WIZone 216635.8%
Dodge County, WIZone 181563.3%
Columbia County, WIZone 231738.6%

The six counties with the nearest centers.

What to do about radon in Green Lake County

Test the building. EPA recommends fixing a home at 4 pCi/L or more and considering a fix between 2 and 4 pCi/L, and says there is no known safe level of exposure. Wisconsin's state radon program can point you to testers and test kits.

Buying here? The Environmental Records Report lists this county's radon zone and test results with the flood zone, mapped faults, power lines and federal contamination records near the address.

Check one Green Lake County address

Environmental Records Report, $29. PDF and JSON, usually ready in about a minute.

Radon in Green Lake County: questions

What is the radon level in Green Lake County?

The median of the 124 laboratory tests reported for Green Lake County (2008 to 2017) was 4.5 pCi/L, and 53.6% of them were at or above 4 pCi/L. These are results of tested buildings; a single home can be far above or below them.

Is Green Lake County in radon Zone 1?

Yes. EPA's 1993 Map of Radon Zones puts Green Lake County in Zone 1, the counties with a predicted average indoor radon screening level above 4 pCi/L.

How does radon in Green Lake County compare with Wisconsin?

53.6% of laboratory tests in Green Lake County were at or above 4 pCi/L for 2008 to 2017, against 47% across Wisconsin (55,359 tests) and 36.5% nationally. 28 of Wisconsin's 72 counties are in Zone 1.

Should I test for radon in Green Lake County?

Yes. EPA recommends testing every home whatever its zone: "This map should not be used to determine if individual homes need to be tested." Fix the home at 4 pCi/L or more and consider a fix between 2 and 4 pCi/L; EPA says there is no known safe level of radon exposure.

More for Green Lake County

Other free hazard lookups

All of these, plus wetlands, FEMA hazard ratings and the federal contamination lists, are in the Environmental Records Report for any US address ($29).

Radon in every Wisconsin county · Radon map of every state

Data compiled 2026-10-20. County FIPS 55047. County-level screening information, not a radon measurement of any building.