Frequently asked questions
What is radon testing?
Radon testing measures radon levels in air, in water, or both, using a device or a laboratory sample. Companies in this guide describe different methods, including continuous monitors, charcoal canisters and electret ion chambers, and different test durations; several describe 48-hour tests. Ask the company which method it uses, how long the test runs, and how results are reported.
What is radon mitigation?
Radon mitigation is the installation of a system that reduces radon levels, for example a sub-slab depressurization system for air, or aeration or granular activated carbon treatment for water. The right system depends on whether the concern is air or water and on the house and foundation type. Ask the company to explain the system it proposes for your home in plain terms.
What level calls for action?
The U.S. Environmental Protection Agency's published guidance recommends action when radon in air is at 4 pCi/L or more. That is a published EPA guideline, not a claim by this guide or by any company listed here. Ask the testing company how it reports results and what it recommends for your specific result.
What is the difference between a testing-only company and a mitigator?
A testing-only company tests for radon and does not install mitigation systems. Some state this explicitly on their own site. If a test result calls for mitigation, a testing-only company cannot install the system itself, so ask in advance who it refers mitigation work to. A mitigation specialist installs systems, and many also test.
What is the difference between radon in air and radon in water?
They are tested and treated differently. Air systems typically use depressurization or ventilation; water systems typically use aeration or carbon filtration. Some companies handle only one of the two. This guide labels each company's scope so you can check before you book.
Do I need to be present for a test?
That depends on the company and the test method. Continuous monitors and laboratory samples have different setup and pickup routines. Ask how the test is placed, how long it must stay undisturbed, and when results arrive.
What happens after mitigation? Is retesting included?
Ask whether a post-mitigation test is included in the quote, when it happens, and what the company does if the follow-up result calls for adjustments. Get the retesting terms in writing.
How do I verify a company's credential?
Ask for the license or certification number and check it yourself against the issuing body. This guide publishes a number only where the company publishes one on its own website, and only 4 of the 23 companies here do. If no number is published, treat the credential as unverified until you check it yourself.
Why do some companies show no rating?
Because their own website publishes no rating figure with a review count. This guide never invents a rating and never presents a review-site figure as if it came from the company's own site. No rating means no rating was found on the company's own site, not that the company is bad.
Why do some companies show no street address?
Because their own website publishes none. This guide states that plainly instead of copying an address from a directory, which may be outdated or belong to a different business with a similar name.
Why is there no fixed mitigation price in this guide?
Because no company in this guide publishes one on its own website. Mitigation quotes depend on the system type, the foundation, the house size and whether the work is for air or water, so a real price comes only after an assessment and a written quote. The only fixed prices published are testing prices from one company, listed in the cost guide.
Should I choose the cheapest quote?
Compare itemized quotes, not headline figures. System type, scope (air, water, rooms), retesting, crew and equipment left in place can all differ between quotes that look similar at first glance.