Test results in Ontonagon County
| Result | Share | EPA guidance |
|---|---|---|
| Below 2 pCi/L | 79% | Below EPA's levels |
| 2 to 4 pCi/L | 18% | Consider fixing |
| 4 pCi/L or more | 4% | EPA recommends fixing |
What the data shows
- Higher share of high results than 2 of 83 Michigan counties.
- Below the Michigan rate of 23%.
- Higher than 1 of 4 neighbouring counties.
- 21% of results at or above 2 pCi/L.
- 10.7 tests per 1,000 homes (Michigan: 12.2).
How Ontonagon County compares
Data table
| Area | Tests ≥ 4 pCi/L | Tests |
|---|---|---|
| Iron County | 35% | 144 |
| Gogebic County | 13% | 149 |
| Houghton County | 10% | 459 |
| Ontonagon County | 4% | 56 |
| Keweenaw County | 0% | 23 |
| Michigan (83 counties) | 23% | 56,518 |
Same source as Ontonagon County. Other bordering counties: Ashland County, Wisconsin, Cook County, Minnesota.
What it means for your home
About 1 in 28 results in Ontonagon 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 →
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: 56. 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