Philadelphia, MO Radon Levels

Q: What EPA Radon Zone is Philadelphia in?

Philadelphia is in Marion County, EPA Zone 2.

Q: How much does radon mitigation cost in Philadelphia?

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

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

Philadelphia, MO Radon Facts

EPA Radon Zone Zone 2 — Moderate Risk 2–4 pCi/L (Zone 2)

County Marion County, MO

Zip Code 63463

Located in northeast Missouri's Marion County, Philadelphia sits on glacial till deposits over limestone bedrock common to this prairie region. Testing data is currently unavailable for this small community, making individual radon testing essential for residents in zip code 63463. The area's older housing stock and agricultural buildings, combined with the underlying geology, create conditions where radon levels can vary significantly between properties.

6.67

pCi/L area average

Above EPA Action Level

Marion County average: 6.67 pCi/L, based on 3 user-submitted tests across 2 cities in the county. No homeowner readings have been submitted for Philadelphia itself yet, so this county figure is the closest available benchmark. The EPA recommends taking action at or above 4.0 pCi/L.

4.0 EPA

10+

Philadelphia, 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 Philadelphia, MO

No homeowner tests have been submitted for Philadelphia 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
Palmyra	11.9 mi	8.00 pCi/L	1
Hannibal	21.6 mi	6.00 pCi/L	2
Mexico	46.5 mi	4.00 pCi/L	1

Marion County Radon Profile

The soils and bedrock of Marion County place it in EPA Radon Zone 2, a moderate-risk classification with predicted indoor averages of 2 to 4 pCi/L. Homeowner-submitted tests from 2 cities in Marion County average 6.67 pCi/L across 3 tests — above the EPA's 4 pCi/L action level, reinforcing the need for testing across the county. Since radon is the second leading cause of lung cancer nationally, the EPA urges every household in Marion County to test, as levels can differ between neighboring homes.

Radon FAQ for Philadelphia, MO

What EPA Radon Zone is Philadelphia in?

Philadelphia and the 63463 zip code are in Marion County, which has an EPA assigned Radon Zone of 2. A zone of 2 predicts an average indoor radon screening level between 2 and 4 pCi/L.

Why are radon readings shown from areas near Philadelphia?

No homeowner radon tests have been submitted for Philadelphia yet. Because radon is driven by regional soil and bedrock geology, readings from the closest cities—and the Marion County average—are the best available indicator of local conditions until Philadelphia 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 Philadelphia?

Radon mitigation in Philadelphia 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 Philadelphia?

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.