Is radon high in ZIP 63664?

Moderate. The model's predicted long-term basement average for ZIP 63664 is 2.1 pCi/L (SD 0.06), with above-ground floors at 1.1 pCi/L. That is close to the average US ZIP code (2.2) and close to the Washington County average of 2.1. It ranks 5 of 9 ZIPs in the county.

Do I need to test my home in 63664?

Yes. 63664's predicted average falls in the EPA's 2-4 pCi/L "consider fixing" band, and a meaningful share of individual homes in such areas test above 4. Test with a short-term kit and confirm anything at 2 or higher with a long-term test.

What EPA radon zone is ZIP 63664 in?

ZIP 63664 lies mostly in Washington County, which the EPA classifies as Radon Zone 2 (moderate potential (2-4 pCi/L)). Zones are county-wide and date from 1993; the ZIP-level prediction above is from a 2001-2021 model built on millions of tests.

Radon levels in ZIP 63664

ModerateEPA Zone 2

ZIP 63664 (Washington County, Missouri): predicted long-term basement average of 2.1 pCi/L (model estimate), close to the average US ZIP (2.2) and close to the Missouri average (2.2). This is the most populous ZIP in Washington County.

Test ZIP 63664 - the EPA says "consider fixing" in this range

The predicted basement average here is 2.1 pCi/L, in the 2-4 pCi/L band where the EPA recommends considering mitigation. Plenty of individual homes in a moderate area test above 4. Start with a short-term test; if it comes back at 2 or higher, follow up with a long-term test or a continuous monitor.

Get a short-term test kit →Or track it with a continuous monitor

Already tested at 4 pCi/L or higher? Find a certified mitigation professional (EPA). A mitigation system typically runs $800-$2,500 installed.

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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.

2.1 ± 0.06

pCi/L predicted basement mean (model SD)

1.1 ± 0.07

pCi/L predicted upstairs mean

1.8 ± 0.06

pCi/L predicted typical screening test

How 63664 compares

Within Washington County, ZIP 63664 ranks #5 of 9 ZIPs by predicted basement level; the county average is 2.1 pCi/L and its ZIPs run from 1.9 to 2.9. The county is EPA Radon Zone 2. About 8,920 people lived in this ZIP at the 2010 Census.

Above-ground floors are predicted at 1.1 pCi/L, below the action level, while basements sit in the 2-4 band. If you spend time in a finished basement, test there first.

Other ZIP codes in Washington County

636602.1
636302.0
636482.2
630712.0
636262.2
636222.0
636312.9
630301.9

ZIP 63664 radon questions

Is radon high in ZIP 63664?: Moderate. The model's predicted long-term basement average for ZIP 63664 is 2.1 pCi/L (SD 0.06), with above-ground floors at 1.1 pCi/L. That is close to the average US ZIP code (2.2) and close to the Washington County average of 2.1. It ranks 5 of 9 ZIPs in the county.
Do I need to test my home in 63664?: Yes. 63664's predicted average falls in the EPA's 2-4 pCi/L "consider fixing" band, and a meaningful share of individual homes in such areas test above 4. Test with a short-term kit and confirm anything at 2 or higher with a long-term test.
What EPA radon zone is ZIP 63664 in?: ZIP 63664 lies mostly in Washington County, which the EPA classifies as Radon Zone 2 (moderate potential (2-4 pCi/L)). Zones are county-wide and date from 1993; the ZIP-level prediction above is from a 2001-2021 model built on millions of tests.

ZIP pages are generated for ZIPs predicted at or above 2.5 pCi/L and for the most populous ZIP in each county; all other ZIPs appear in their county table. Methodology.