Potosi, MO Radon Levels

Q: What EPA Radon Zone is Potosi in?

Potosi is in Washington County, EPA Zone Unknown.

Q: Why are radon readings shown from areas near Potosi?

No homeowner radon tests have been submitted for Potosi yet, so readings from the closest cities and the Washington County average are used as the best available indicator of local conditions. The EPA recommends testing every individual home.

Q: How much does radon mitigation cost in Potosi?

Radon mitigation typically costs between $800 and $2,000. Most standard systems fall in the $1,000-$1,500 range.

Check local Potosi radon levels and find certified testing and mitigation professionals to keep your home safe

Potosi, MO Radon Facts

EPA Radon Zone Unknown Unknown

County Washington County, MO

Zip Code 63664

Potosi sits in Missouri's historic lead belt within Washington County, where Precambrian granite and rhyolite bedrock can contribute to elevated radon levels. Testing data for zip code 63664 remains limited, though the area's unique geology warrants careful attention from homeowners. The community's mix of older mining-era housing and newer construction creates varied foundation types that may influence radon entry rates.

7.46

pCi/L area average

Above EPA Action Level

Nearby homeowner readings average 7.46 pCi/L, based on 13 tests from 10 nearby cities. No readings have been submitted for Potosi yet, so the closest recorded data is shown as a benchmark. The EPA recommends taking action at or above 4.0 pCi/L.

4.0 EPA

10+

Potosi, MO Radon Mitigation

Professional radon mitigation is the most effective way to permanently lower radon levels and protect your household.

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Radon Readings Near Potosi, MO

No homeowner tests have been submitted for Potosi yet. The closest cities with user-submitted radon data are shown below — explore them to gauge local conditions. Radon varies by home, so testing is the only way to know your level.

City	Distance	Avg User Level	Readings
Bonne Terre	15.7 mi	4.50 pCi/L	2
De Soto	19.4 mi	11.00 pCi/L	1
Bourbon	25.6 mi	6.00 pCi/L	1
Leasburg	26.5 mi	4.00 pCi/L	1
Farmington	26.6 mi	9.50 pCi/L	2
Festus	27.6 mi	5.00 pCi/L	2
Cuba	32.3 mi	5.00 pCi/L	1
House Springs	35.2 mi	7.00 pCi/L	1

Washington County Radon Profile

Washington County has not been assigned a definitive EPA radon zone, so the agency recommends that every home be tested regardless of predicted risk. User-submitted readings are still sparse within Washington County itself, so the nearby measurements shown on this page provide the closest real-world picture of local radon conditions. Radon is the second leading cause of lung cancer in the United States, and a short-term test is the only way to confirm a specific home's level in Washington County.

Radon FAQ for Potosi, MO

What EPA Radon Zone is Potosi in?

Potosi and the 63664 zip code are in Washington County, which has an EPA assigned Radon Zone of Unknown. A zone of Unknown does not have sufficient data for classification.

Why are radon readings shown from areas near Potosi?

No homeowner radon tests have been submitted for Potosi yet. Because radon is driven by regional soil and bedrock geology, readings from the closest cities—and the Washington County average—are the best available indicator of local conditions until Potosi homeowners submit their own results. The EPA still recommends testing every individual home, since levels can vary significantly from house to house.

How much does radon mitigation cost in Potosi?

Radon mitigation in Potosi typically costs between $800 and $2,000. Most homes with standard basements can be mitigated with a sub-slab depressurization system in the $1,000–$1,500 range. Factors that can increase cost include complex foundations, crawl spaces, or very high radon levels.

Should I test for radon if I'm buying a home in Potosi?

Yes. Radon testing should be part of every home purchase. A short-term radon test is typically included as part of the home inspection process and costs $150–$250. If elevated levels are found, you can negotiate mitigation as part of the sale.