37%tests ≥ 4 pCi/L
4,504tests on record
—median pCi/L
Zone 1EPA zone (1993 prediction)

Test results in Washtenaw County

ResultShareEPA guidance
Below 2 pCi/L35%Below EPA's levels
2 to 4 pCi/L28%Consider fixing
4 pCi/L or more37%EPA recommends fixing

What the data shows

Where Washtenaw County sits among Michigan's 83 counties with dataEach dot is a county's share of tests at or above 4 pCi/L · Michigan indoor radon test results, 2016–2026
0%20%40%60%

How Washtenaw County compares

Washtenaw County ranks 3 of 7 among its neighboursShare of tests at or above 4 pCi/L · Michigan indoor radon test results, 2016–2026 · whisker: 95% range
Lenawee County51%Jackson County47%Washtenaw County37%Livingston County37%Monroe County27%Oakland County23%Wayne County15%Michigan 23%
Data table
AreaTests ≥ 4 pCi/LTests
Lenawee County51%1,004
Jackson County47%875
Washtenaw County37%4,504
Livingston County37%3,463
Monroe County27%722
Oakland County23%8,702
Wayne County15%2,304
Michigan (83 counties)23%56,518

Same source as Washtenaw County.

What it means for your home

About 1 in 3 results in Washtenaw 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.

Prefer a digital monitor? See Airthings radon monitors, or enter code radonbycounty-10OFF at their discount store for 10% off.

Fixing high radon

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

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

Buying or selling here

Michigan's Seller's Disclosure Statement asks whether the seller knows of environmental hazards on the property, including radon gas (MCL 565.957). Source

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

About this data

Source: Michigan indoor radon test results (Michigan Department of Environment, Great Lakes, and Energy). Period: 2016–2026. Tests: 4,504. 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