Certified radon testing uses calibrated equipment and a credentialed technician to measure the radon concentration in your home’s air, reported in picocuries per liter (pCi/L). The EPA sets the action level at 4.0 pCi/L. If your result meets or exceeds that number, mitigation is recommended. A certified test gives you a defensible, documented result, whether you need it for your own peace of mind or for a real estate transaction.
What certified radon testing actually involves
A certified radon test is not a DIY kit mailed back to a lab. A credentialed technician places a professional-grade device in the lowest livable area of your home, records the closed-house start conditions, and returns to retrieve the device after the required exposure period. The result is documented on a written report tied to your property address.
The two main device types are the charcoal canister, a passive short-term option, and the Continuous Radon Monitor (CRM), an active electronic device that logs readings at set intervals throughout the test period. CRMs are common in real estate transactions because they produce a tamper-evident record showing radon levels hour by hour. Alpha track detectors are used for long-term testing, typically 90 days or more.
Closed-house conditions are required for the duration of a short-term test. That means keeping windows closed, exterior doors closed except for normal entry and exit, and HVAC systems running on recirculation rather than fresh-air intake. Violating closed-house conditions can invalidate the test.
Is radon a problem in Atlanta even though the climate is warm?
Yes. Radon comes from the ground, not from cold air. The granite and gneiss bedrock that underlies much of North Georgia is naturally uranium-bearing, and uranium decays into radium, which decays into radon gas. That gas migrates upward through soil and enters homes through foundation cracks, gaps around pipes, and slab penetrations regardless of outdoor temperature.
The EPA’s radon zone map designates several counties in the Atlanta metro as Zone 1 or Zone 2, meaning elevated potential. Fulton, Cobb, and DeKalb counties, all within the Atlanta service area, carry that designation. Forsyth and Cherokee counties farther north, also in the service area, sit in some of the highest-risk geology in the state.
Warm-weather markets often have lower testing rates than northern states, which means more homes with elevated radon that have never been measured.
What is the average radon level in Atlanta-area homes?
The EPA’s national average indoor radon level is approximately 1.3 pCi/L. Atlanta-area homes vary considerably depending on foundation type, soil conditions, and local geology. Homes in counties with granite-rich bedrock tend to run higher. The only way to know your home’s actual level is to test it. A radon level assessment in Atlanta gives you a specific number for your specific property.
What radon level requires mitigation in Georgia?
The EPA action level is 4.0 pCi/L. At or above that concentration, the EPA recommends installing a mitigation system. The World Health Organization sets its reference level lower, at 2.7 pCi/L, and many health-focused homeowners and buyers choose to act at that threshold.
Georgia follows federal EPA guidance. There is no state law that mandates mitigation at a specific level, but levels at or above 4.0 pCi/L are the standard trigger for action in both home sales and general residential practice.
Radon level
Recommended action
Below 2.0 pCi/L
No action typically required; retest in a few years
2.0 to 2.6 pCi/L
Consider long-term testing to confirm
2.7 to 3.9 pCi/L
Mitigation is worth serious consideration (WHO threshold)
4.0 pCi/L and above
EPA recommends mitigation
Do slab-on-grade homes in Atlanta have radon problems?
Yes. Slab-on-grade is by far the most common foundation type in Atlanta, and it does not protect against radon. Radon enters through hairline cracks in the slab, the gap where the slab meets the foundation wall, and around any pipe or conduit penetration. A thicker slab does not meaningfully reduce this.
Homes with basements or crawl spaces also appear throughout the metro, particularly in older neighborhoods and in the hillier counties north of the city. Each foundation type requires its own testing placement protocol and, if mitigation is needed, its own system design. Sub-Slab Depressurization is the standard approach for slab and basement foundations. Sub-Membrane Depressurization applies to crawl spaces with a soil floor.
What is the difference between a short-term and long-term radon test?
A short-term radon test runs for 48 to 96 hours under closed-house conditions. It gives a fast result, which is why it is used in real estate transactions. A long-term test uses an alpha track detector left in place for 90 days to a year, producing a result that reflects seasonal variation and gives a more accurate picture of your year-round exposure.
For annual home monitoring or initial screening with no time pressure, a long-term test is more informative. For a real estate deadline, a short-term radon test in Atlanta is the practical choice. If a short-term result comes back elevated, many buyers and sellers choose to follow up with a long-term test after any mitigation system is installed.
Which radon test is required when buying or selling a home in Atlanta?
Georgia does not mandate radon testing in real estate transactions by law. The Georgia Seller’s Property Disclosure Act (O.C.G.A. § 44-1-16) requires sellers to disclose known material defects, and a prior radon test result can qualify as one. In practice, buyers routinely request radon testing as part of the inspection period, and the test is nearly always a short-term test using a CRM.
If you are selling, having a certified test on file before you list gives you a clean disclosure and removes a common negotiation point. If you are buying, insist on a test conducted by an NRPP or NRSB certified professional. A certified technician produces a report that holds up in the transaction and cannot be challenged for protocol violations.
How the testing process works, from booking to results
Booking is straightforward. You pick a time when your household can maintain closed-house conditions for the test period. The technician arrives, inspects the lowest livable area of the home, and places the testing device in the correct location per ANSI/AARST standards.
For a short-term CRM test:
Technician places the device and notes start time and conditions.
Your household keeps windows and exterior doors closed for 48 to 96 hours.
Technician returns, retrieves the device, and downloads the data.
You receive a written report, typically the same day or within 24 hours.
If results are at or above the action level, the next step is residential radon testing and mitigation planning. The testing report documents the pre-mitigation baseline, which is also needed for the post-mitigation verification test required within 30 days of any system installation.
Service is available across the Atlanta metro area including Fulton, Cobb, DeKalb, Forsyth, Newton, Clayton, Douglas, Hall, Gordon, and Pickens counties.
Why certification matters when choosing a radon tester
Anyone can buy a radon test kit. Certification means the technician has passed written exams, demonstrated field competency, and is required to maintain their credential through continuing education. The two main credentialing bodies are NRPP (National Radon Proficiency Program) and NRSB (National Radon Safety Board). Either credential indicates the technician follows AARST measurement standards.
In a real estate transaction, an uncertified test result can be rejected by a buyer’s agent or lender. A certified result is documented, traceable, and defensible. It also gives you a clean baseline if you later need to demonstrate that a mitigation system worked.
For broader context on indoor air quality and environmental health services available in the Atlanta area, see the environmental health service services page.
Does homeowners insurance cover radon mitigation in Georgia?
Standard homeowners insurance policies do not cover radon mitigation. Radon is classified as a gradual environmental condition, and most policies exclude gradual damage or contamination. Mitigation system costs are typically an out-of-pocket expense for the homeowner.
In a home purchase, mitigation costs are sometimes negotiated between buyer and seller once a test result comes back elevated. The cost of a mitigation system varies depending on foundation type, house size, and how many suction points are needed. Testing is a separate, lower cost and is the necessary first step before any mitigation decision is made.
Frequently asked questions
How long does a certified radon test take?
A short-term test takes 48 to 96 hours of closed-house exposure plus the technician’s placement and retrieval visits. Results are typically available the same day the device is retrieved. A long-term test takes 90 days to one year.
Can I be home during the radon test?
Yes. You just need to maintain closed-house conditions: no open windows, no open exterior doors beyond normal entry and exit, and no whole-house fans during the test period. Normal daily activity inside the home is fine.
What happens if my radon level comes back high?
A result at or above 4.0 pCi/L means you should have a mitigation system installed. Active Sub-Slab Depressurization is the most common method for Atlanta-area slab homes. A PVC vent pipe is routed from a suction pit drilled through the slab to the exterior, and a radon fan pulls soil gas out before it enters the living space. A post-mitigation verification test, run within 30 days of installation, confirms the system is working.
How often should I retest for radon?
The EPA recommends retesting every two years if your level was previously below the action level, and after any major renovation, addition, or change to the HVAC system. If you have a mitigation system installed, a post-mitigation test is required, and periodic retesting every two years is a reasonable interval to confirm the system is still performing.
Is radon testing required before selling a home in Georgia?
No state law in Georgia requires it. But the Seller’s Property Disclosure Act means a known elevated result must be disclosed. Many sellers test before listing to know where they stand. Many buyers require it during the inspection period. In either case, the test needs to be done by a certified professional to be usable in the transaction.
