Located in Sullivan County in New Hampshire's Upper Valley region, Grantham sits on glacial till deposits that contribute to elevated radon potential. Testing data from zip code 03753 shows an average radon level of 12.5 pCi/L, which significantly exceeds the EPA action level of 4.0 pCi/L. Given the area's geological conditions and these elevated readings, all Grantham homeowners should prioritize radon testing and mitigation if necessary.
12.50
pCi/L average
Above EPA Action Level
Based on 2 user-submitted radon tests for homes in Grantham, NH. The EPA recommends taking action at or above 4.0 pCi/L.
0
4.0 EPA
10+
Grantham, NH Radon Mitigation
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User-submitted radon test readings from homes in the Grantham area.
Radon Level
City
Home Age
Foundation
20 pCi/L
Grantham, NH
0-20 Years
No Basement/All Slab
5 pCi/L
Grantham, NH
21-50 Years
Full Basement
Have a radon test result for Grantham? Submit your reading to help other homeowners.
Radon FAQ for Grantham, NH
What is the average radon level in Grantham, NH?
Based on 2 user-submitted tests, the average radon level in Grantham is 12.50 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 Grantham in?
Grantham and the 03753 zip code are in Sullivan 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.
How much does radon mitigation cost in Grantham?
Radon mitigation in Grantham 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 Grantham?
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.
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