28%tests ≥ 4 pCi/L
1,025tests on record
2.2median pCi/L
Zone 1EPA zone (1993 prediction)

Test results in Richland County

ResultShareEPA guidance
Below 2 pCi/L45%Below EPA's levels
2 to 4 pCi/L26%Consider fixing
4 pCi/L or more28%EPA recommends fixing

What the data shows

Where Richland County sits among Wisconsin's 72 counties with dataEach dot is a county's share of tests at or above 4 pCi/L · Wisconsin county radon test results, 2005–2017
0%20%40%60%

How Richland County compares

Richland County has the lowest share of high results among its neighboursShare of tests at or above 4 pCi/L · Wisconsin county radon test results, 2005–2017 · whisker: 95% range
Grant County59%Vernon County55%Iowa County55%Crawford County54%Sauk County34%Richland County28%Wisconsin 42%
Data table
AreaTests ≥ 4 pCi/LTests
Grant County59%2,375
Vernon County55%1,434
Iowa County55%1,172
Crawford County54%911
Sauk County34%2,444
Richland County28%1,025
Wisconsin (72 counties)42%194,443

Same source as Richland County.

What it means for your home

About 1 in 4 results in Richland 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 →

Wisconsin doesn't license radon mitigators; look for NRPP or NRSB certification. Source

Buying or selling here

Wisconsin sellers must tell buyers about any known unsafe radon levels through the Real Estate Condition Report (Wis. Stat. § 709.03). Source

Checked against the official text on 2026-11-03. Not legal advice.

About this data

Source: Wisconsin county radon test results (Wisconsin Department of Health Services). Period: 2005–2017. Tests: 1,025. 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