Griswold is located in Cass County, Iowa.
With 1 user-submitted readings averaging 20.00 pCi/L,
the area exceeds the EPA's 4.0 pCi/L action threshold, and testing is strongly recommended for homeowners in the 51535 zip code.
20.00
pCi/L average
Above EPA Action Level
Based on 1 user-submitted radon test for homes in Griswold, IA. The EPA recommends taking action at or above 4.0 pCi/L.
0
4.0 EPA
10+
Griswold, IA Radon Mitigation
Professional radon mitigation is the most effective way to permanently lower radon levels and protect your household.
Griswold, IA Radon Testing
Finding qualified radon testing professionals is the first step toward protecting your home.
Griswold, Iowa Radon Levels
User-submitted radon test readings from homes in the Griswold area.
Radon Level
City
Home Age
Foundation
Submitted
20 pCi/L
Griswold, IA
0-20 Years
Full Basement
Mar 2025
Have a radon test result for Griswold? Submit your reading to help other homeowners.
Griswold Radon Facts
Key details about the radon risk profile for Griswold and the 51535 zip code area.
EPA Radon Zone
Zone 1 — High Risk
County
Cass County, IA
Zip Code
51535
Predicted Screening Level
> 4.0 pCi/L (Zone 1)
Avg. User Submitted Level
20.00 pCi/L
User Tests Submitted
1
Griswold and the 51535 zip code are located in Cass County, which has an EPA assigned Radon Zone of 1. A radon zone of 1 predicts an average indoor radon screening level greater than 4 pCi/L. The EPA recommends testing every home regardless of zone classification.
Radon FAQ for Griswold, IA
What is the average radon level in Griswold, IA?
Based on 1 user-submitted test, the average radon level in Griswold is 20.00 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 Griswold in?
Griswold and the 51535 zip code are in Cass County, which has an EPA assigned Radon Zone of 1. A zone of 1 predicts an average indoor radon screening level greater than 4 pCi/L.
How much does radon mitigation cost in Griswold?
Radon mitigation in Griswold 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 Griswold?
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 Iowa
Cities with the most user-submitted radon test data in the state.
