Verified ranking
Best Radon Mitigation in Nashua, NH
How we rank (the Bedrock Standard). Every figure below is dated and sourced; star ratings change over time. We read five-star share together with review depth, so a near-perfect share on a large review base counts for more than a perfect score on a small one.
An NRPP-certified Radon Mitigation Specialist (cert no. 113966-RMS), BBB A+ accredited, with a transferable warranty and the cleanest proportional record in the group (4.9 across 250 Google reviews, 97.6 percent five-star), handling radon in-house alongside the moisture and foundation work it often accompanies. It leads on our composite standard. Honest caveat: the dedicated radon-only specialists below carry deeper radon-only review counts, so for radon-only mitigation weigh them directly.
A Nashua-based radon testing and mitigation specialist that leads the Nashua radon local pack with a perfect headline rating (5.0 across 98 Google reviews). The full review breakdown was not available at publication, so we rank it on headline rating and review count; a strong dedicated radon-only choice in Nashua.
The regional radon leader from Hooksett (4.9 across 304 Google reviews, NRPP-certified, more than 25 years), with the deepest and fully verified radon-only review record of any firm serving Nashua. The dedicated radon-only pick if you weight verified depth most.
Also serving the area
A full-service foundation firm and National Radon Defense contractor (4.8 across 676) that also handles radon mitigation.
Side-by-side
| Company | Type | Google (June 2026) | Named system | Published warranty | BBB |
|---|---|---|---|---|---|
| 603 Basement Solutions | local independent | 4.9 / 250 | Forever Dry System | Publishes a transferable "Dry for Life" guarantee (marketing wording; exact written terms pending). | A+, BBB accredited since 2022 |
| Airtight Radon Solutions | local independent | 5 / 98 | None | Not stated on its website; ask at quote. | Not assessed here |
| Advanced Radon Mitigation & Water Treatment | local independent | 4.9 / 304 | None | Not independently verified; ask at quote. | Not assessed here |
| Erickson Foundation Solutions | local national brand | 4.8 / 676 | Installs the national Basement Systems line (TripleSafe, SaniDry, WaterGuard) rather than a self-branded system | Transferable written warranty (duration not stated). | A+, accredited 2015, 2 complaints (3yr) |
Head-to-head comparisons
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Data verified as of the dates shown; star ratings change over time. See our methodology.