Located in Grafton County within New Hampshire's White Mountain region, Thornton sits over granite bedrock and glacial soils known to produce elevated radon levels throughout the state. The area's homes range from historic New England construction to modern ski country residences, many featuring full basements or walkout basement designs. Given limited current testing data for zip code 03285, residents should prioritize radon testing to ensure indoor air safety.
Thornton, NH Radon Mitigation
Professional radon mitigation is the most effective way to permanently lower radon levels and protect your household.
Thornton, NH Radon Testing
Finding qualified radon testing professionals is the first step toward protecting your home.
Thornton Radon Facts
Key details about the radon risk profile for Thornton and the 03285 zip code area.
EPA Radon Zone
Zone 2 — Moderate Risk
County
Grafton County, NH
Zip Code
03285
Predicted Screening Level
2–4 pCi/L (Zone 2)
Thornton and the 03285 zip code are located in Grafton County, which has an EPA assigned Radon Zone of 2. A radon zone of 2 predicts an average indoor radon screening level between 2 and 4 pCi/L. The EPA recommends testing every home regardless of zone classification.
Radon FAQ for Thornton, NH
What EPA Radon Zone is Thornton in?
Thornton and the 03285 zip code are in Grafton 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 Thornton?
Radon mitigation in Thornton 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 Thornton?
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 New Hampshire
Cities with the most user-submitted radon test data in the state.
