Advanced Radon Mitigation & Water Treatment

Advanced Radon Mitigation & Water Treatment is a Hooksett, New Hampshire, radon and well-water specialist that has been in business since 1998 — nearly three decades — serving homeowners, realtors and builders across Southern, Central and Coastal New Hampshire, with an A+ Better Business Bureau accreditation and a Google history few local contractors match: 4.9 stars from 311 ratings, built on 222 reviews since 2021. What stands out across that record is how many customers describe using ARM repeatedly over long stretches — one 2026 review cites 12 years of consistent service, another describes almost 20 years, a third three years running — and how consistently the same names come up: Keith is credited again and again for walking homeowners through radon options and explaining the reasoning behind a recommendation; Cory shows up in reviews spanning 2025 and 2026 for careful, well-explained installs; Cody and office coordinator Tiffany are singled out in a November 2025 review for a smooth scheduling-to-install handoff. The results reviewers describe are specific, not just glowing. A 2023-09-12 review reported radon dropping from 14 pCi/L to under 1 pCi/L after installation; a 2025-08-04 review described a fan-in-attic system bringing levels down from the 12–14 range while the installers were careful not to disturb existing blown-in insulation. A 2026-02-02 review said ARM was the only company among several it compared that used licensed plumbers and electricians to complete the installation, not just its own crew. Recent reviews also describe broader water-side work — a combined radon air, water and PFAS system in a December 2025 review, and an arsenic water mitigation system installed five years earlier that's still being maintained today. There is one real exception in an otherwise clean record: a review dated December 2021 carries a 5-star Google rating that doesn't match what it describes — the reviewer said a water filtration system installed for iron staining, which cost over $3,000, stopped working within a year and the staining came back, and they were charged separately for a water test that should have been part of the original job. It reads as an older, isolated account rather than a pattern, but it's worth asking about directly if a similar filtration job is under discussion. Given the volume and consistency here, ARM is a strong pick for radon work in particular; for a larger water-treatment project, it's still worth getting the scope and any follow-up testing spelled out in writing up front.