Radon levels in McLean County, Kentucky

LowEPA Zone 2

Predicted long-term basement average of 1.9 pCi/L (model estimate) across 5 ZIP codes - close to the US average of 1.8, about 23% below the Kentucky average of 2.5. Ranked #108 of 120 Kentucky counties.

Test McLean County, KY once anyway - radon varies house to house

The predicted basement average here is 1.9 pCi/L, below the EPA's 2 pCi/L "consider fixing" threshold. That's good news for the area - but the EPA still recommends every home be tested, because foundation cracks, soil pockets and ventilation make one house very different from its neighbor. One inexpensive kit settles it.

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Predicted (model estimate). The pCi/L figures on this page are long-term area averages from a peer-reviewed national model built on millions of real radon tests (2001-2021). They describe the typical home in this area - not your home, which can be several times higher or lower. The EPA radon zone is a separate, 1993 county-level classification. How the numbers work.

1.9 ± 0.06

pCi/L predicted basement mean (model SD)

1.0 ± 0.06

pCi/L predicted upstairs (above-ground) mean

1.6-2.0

range of ZIP-level basement predictions in the county

What this means for McLean

The typical McLean County home is predicted below 2 pCi/L, the lowest band. That is the best case an area can show - but it describes the average house, and the ZIP-level predictions within the county still span 1.6 to 2.0 pCi/L.

Note that the EPA classifies McLean County as Zone 2 while the newer model predicts 1.9 pCi/L. The zone map predates two decades of test data; where they disagree, we grade on the model but show both. County figures weight each ZIP by its 2010 Census population, so they describe where people live rather than empty land.

Comparable Kentucky counties: Hopkins County (1.9), Union County (1.9), Henderson County (1.9), Kenton County (1.9). The state's highest is Jessamine County at 3.7 pCi/L.

ZIP codes in McLean County

Predicted basement and upstairs means by ZIP (model estimate). ZIPs whose land is mostly in this county.

ZIPBasementUpstairsGrade
423272.0 ± 0.061.1Moderate
423521.8 ± 0.061.0Low
423721.8 ± 0.051.0Low
423501.9 ± 0.061.1Low
423711.6 ± 0.060.9Low

If your test comes back at 4 pCi/L or higher

Mitigation is a routine job: a fan-driven pipe that vents soil gas from under the slab to above the roofline, typically $800-$2,500 installed (typical range; local quotes vary). Use certified professionals: EPA find-a-professional. Read the full mitigation guide.

McLean County radon questions

Is radon high in McLean County, Kentucky?
Low. The model predicts a long-term basement average of 1.9 pCi/L in McLean County (close to the US average of 1.8 and about 23% below the Kentucky average of 2.5). That is below the EPA's 2 pCi/L "consider fixing" threshold, though individual homes still vary. Ranked 108 of 120 Kentucky counties.
Should I test for radon in McLean County?
Yes, once. The EPA recommends testing every home regardless of area, and the model's ZIP-level predictions in McLean County already range from 1.6 to 2.0 pCi/L. A short-term kit costs little and settles the question for your house.
What does EPA Radon Zone 2 mean for McLean County?
Zone 2 - moderate potential (2-4 pCi/L). The zone map dates from 1993 and classifies whole counties. The newer model's predicted average of 1.9 pCi/L does not line up with Zone 2, which is common - the EPA itself says high-radon homes exist in every zone. Neither replaces a test of your own home.
How much does radon mitigation cost in McLean County?
A standard active sub-slab depressurization system typically runs $800-$2,500 installed nationally; Kentucky quotes vary with foundation type (slab, crawlspace, basement), home size and local labor. Get two or three bids from certified mitigators listed by your state radon program or the EPA's find-a-professional page.

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