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San Antonio, TX Radon Levels

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


San Antonio, TX Radon Facts

EPA Radon Zone Zone 3 — Low Risk < 2.0 pCi/L (Zone 3)
County Bexar County, TX
Zip Code 78201
Avg. User Level 8.10 pCi/L
User Tests 8

Texas's second-largest city in Bexar County shows an average radon level of 6.57 pCi/L, which exceeds the EPA action threshold of 4.0 pCi/L. Built primarily on Edwards Plateau limestone and clay soils, the city's diverse housing stock ranges from historic downtown structures to modern suburban developments, with most featuring concrete slab foundations. Testing data from seven measurements across multiple zip codes (78201-78211) reveals readings from 3.0 to 17.0 pCi/L, demonstrating significant variation that makes individual home testing essential for residents throughout the San Antonio metro area.

8.10
pCi/L average
Above EPA Action Level

Based on 8 user-submitted radon tests for homes in San Antonio, TX. The EPA recommends taking action at or above 4.0 pCi/L.

0
4.0 EPA
10+

San Antonio, TX Radon Mitigation

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San Antonio, TX Radon Levels

User-submitted radon test readings from homes in the San Antonio area.

Radon LevelCityHome AgeFoundation
3 pCi/L San Antonio, TX 0-20 Years No Basement/All Slab
3 pCi/L San Antonio, TX 0-20 Years No Basement/All Slab
8 pCi/L San Antonio, TX 21-50 Years No Basement/All Slab
5 pCi/L San Antonio, TX 21-50 Years No Basement/All Slab
7 pCi/L San Antonio, TX No Basement/All Slab

Have a radon test result for San Antonio? Submit your reading to help other homeowners.

Radon FAQ for San Antonio, TX

What is the average radon level in San Antonio, TX?
Based on 8 user-submitted tests, the average radon level in San Antonio is 8.10 pCi/L. This exceeds the EPA's recommended action level of 4.0 pCi/L, and radon testing is recommended for all homes in the area.
What EPA Radon Zone is San Antonio in?
San Antonio and the 78201 zip code are in Bexar County, which has an EPA assigned Radon Zone of 3. A zone of 3 predicts an average indoor radon screening level less than 2 pCi/L.
How much does radon mitigation cost in San Antonio?
Radon mitigation in San Antonio 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 San Antonio?
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.

Most Active Radon Markets in Texas

Cities in Texas with the most user-submitted radon test data, ranked by number of submissions.

CityAvg User Radon LevelSubmissions
Lubbock 12.70 pCi/L 10
San Antonio 6.57 pCi/L 7
Austin 6.14 pCi/L 7
Dallas 8.00 pCi/L 5
Abilene 4.50 pCi/L 2
Houston 3.50 pCi/L 2
Plano 6.00 pCi/L 1
Frisco 3.00 pCi/L 1
Nacogdoches No submissions 0