Verified ranking · Updated June 2026
Best Radon Mitigation in the NH Seacoast (Exeter area)
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.
The deepest-reviewed radon specialist in the region (4.9 across 304 Google reviews, June 2026), NRPP-certified with more than 25 years in radon air and water mitigation, and first in the Exeter radon local pack.
A Dover-based radon air mitigation specialist, veteran-owned and NH-certified for more than 23 years (4.6 across 19 Google reviews), second in the Exeter radon local pack. A focused specialist on a smaller but solid review base.
A radon specialist with a perfect headline rating (5.0 across 98 Google reviews), third in the Exeter radon local pack. The full review breakdown was not available at publication, so we rank it on headline rating and review count.
Also serving the area
Locally owned in East Kingston and handles radon mitigation in-house alongside waterproofing and foundation (4.9 across 250). A strong local full-service option on the Seacoast, though dedicated specialists lead the radon pack.
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 |
|---|---|---|---|---|---|
| Advanced Radon Mitigation & Water Treatment | local independent | 4.9 / 304 | None | Not independently verified; ask at quote. | Not assessed here |
| Radon Clear LLC | local independent | 4.6 / 19 | None | Not stated on its website; ask at quote. | Not assessed here |
| Airtight Radon Solutions | local independent | 5 / 98 | None | Not stated on its website; ask at quote. | Not assessed here |
| 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 |
| 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
Other services in the NH Seacoast (Exeter area)
- Best Basement Waterproofing in the NH Seacoast (Exeter area)
- Best Foundation Repair in the NH Seacoast (Exeter area)
- Best Crawl Space Encapsulation in the NH Seacoast (Exeter area)
Data verified as of the dates shown; star ratings change over time. See our methodology.