41%tests ≥ 4 pCi/L
342tests on record
3.1median pCi/L
Zone 1EPA zone (1993 prediction)

Test results in Grundy County

ResultShareEPA guidance
Below 2 pCi/L30%Below EPA's levels
2 to 4 pCi/L30%Consider fixing
4 pCi/L or more41%EPA recommends fixing

What the data shows

Where Grundy County sits among Illinois's 102 counties with dataEach dot is a county's share of tests at or above 4 pCi/L · Radon test results from laboratories, 2008–2017
0%20%40%60%80%

How Grundy County compares

Grundy County has the lowest share of high results among its neighboursShare of tests at or above 4 pCi/L · Radon test results from laboratories, 2008–2017 · whisker: 95% range
Livingston County61%LaSalle County52%Kendall County47%Will County43%Kankakee County42%Grundy County41%Illinois 43%
Data table
AreaTests ≥ 4 pCi/LTests
Livingston County61%215
LaSalle County52%863
Kendall County47%1,128
Will County43%5,578
Kankakee County42%379
Grundy County41%342
Illinois (102 counties)43%108,909

Same source as Grundy County.

What it means for your home

About 1 in 2 results in Grundy County were at or above 4 pCi/L, where the EPA recommends a fix. Only a test shows your own home's level.

Levels in pCi/L from the EPA. The WHO reference level is 100 Bq/m³, about 2.7 pCi/L.

Test your home

Start with a short-term test (2–90 days) and confirm a result of 4 pCi/L or more with a second test. EPA guide

Sponsored: we earn a commission on purchases through these links. We haven't tested Airthings monitors yet.

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Fixing high radon

No local job records yet. National range: $800–$2,500, average $1,200 (EPA, 2003). Cost guide →

About this data

Source: Radon test results from laboratories (CDC Environmental Public Health Tracking Network). Period: 2008–2017. Tests: 342. Read the methodology →

These are voluntary and real-estate tests, not a random sample of homes, so they describe tested homes rather than every home.

About this page

Published by Ray Roman, editor of Radon by County. Figures are loaded from the cited source and spot-checked against it. Editorial policy · About us