If a radon test came back at or above the EPA action level of 4 pCi/L, the next step is to confirm the result with a second test and then mitigate. EPA recommends fixing homes at 4 pCi/L or higher, and considering a fix between 2 and 4 pCi/L. Mitigation is a physical fix — usually a sub-slab depressurization system that vents soil gas above the roofline — not a cleaning or a chemical treatment. Environmental Services of America (ES America) works with homeowners across North Georgia from our Bogart office serving Athens and the surrounding area. Call (770) 758-2027.
Last updated July 2026 · By D.K.H.
A high radon number is unsettling, but it is one of the more solvable problems a house can hand you. Radon is a naturally occurring radioactive gas that seeps out of soil and rock and accumulates indoors — and unlike most environmental issues, the fix is mechanical, permanent, and verifiable. Here is what the number means and what happens next.
What does a high radon result actually mean?
Radon is measured in picocuries per liter (pCi/L). The EPA’s action level is 4 pCi/L: at or above that, EPA recommends taking action to reduce the level. Between 2 and 4 pCi/L, EPA says a homeowner should consider fixing. There is no level EPA calls “safe” — the guidance is to get the concentration as low as reasonably achievable. EPA identifies radon as the leading cause of lung cancer among people who have never smoked, which is why the agency treats it as a fix-it item rather than a monitor-it item. A single elevated reading is not a verdict on your house; it is a signal to confirm and act.
Should I retest before I do anything?
Usually yes. Radon levels swing with weather, season, soil moisture, and how the house is being ventilated, so a single short-term test (typically 2–7 days) is a snapshot, not an average. Standard practice after a high short-term result is to confirm it — either with a second short-term test under closed-house conditions, or with a long-term test (90+ days) that averages out the swings and better reflects true annual exposure. Two exceptions where people skip straight to mitigation: a result that is dramatically over the action level, and a real-estate transaction on a deadline. If you need the confirming measurement, start with radon testing.
How is a high radon level fixed?
The standard fix for a house with a slab or basement is active sub-slab depressurization. A pipe is sealed into the slab, a continuously running in-line fan pulls soil gas from beneath the foundation before it can enter the living space, and the pipe vents it above the roofline where it disperses. Crawl spaces are handled differently — typically a sealed vapor barrier with a suction point underneath. Foundation cracks and sump openings get sealed as a supporting measure, but sealing alone is not a radon fix: it slows entry without giving the gas anywhere else to go. Installation on a typical house is measured in hours, not weeks. See radon mitigation for how the system is designed and installed.
Is North Georgia a high-radon area?
Parts of it are. Radon comes from uranium in the underlying geology, and the Piedmont and Blue Ridge regions of North Georgia — including the Athens area and the counties around it — contain granitic and metamorphic rock associated with elevated radon potential. But zone maps are planning tools, not predictions: two houses on the same street can test very differently depending on foundation type, construction, and how the house breathes. The only way to know your number is to test your house. Our Bogart office serves Athens and the surrounding area.
How do I know the fix worked?
You retest. A mitigation system is not finished when the fan turns on — it is finished when a post-mitigation measurement shows the level has come down and stayed down, and the system has a working manometer (the U-tube gauge on the pipe) so you can see at a glance that it is still pulling. EPA also recommends retesting every couple of years, and again after any major renovation, foundation work, or HVAC change that alters how the house moves air. That is the whole loop: test, confirm, mitigate, verify.
Why ES America?
Environmental Services of America (ES America) has provided environmental work across Georgia, South Carolina, and Alabama since 2009, and the same discipline we bring to asbestos and mold applies to radon: measure first, act on the measurement, verify the result. Because we also handle asbestos, lead, and mold, an older home that turns up more than one issue during a pre-sale or pre-renovation workup doesn’t become three contractors and three schedules. ES America is insured $1M/$3M.
FAQ
What radon level is dangerous?
EPA’s action level is 4 pCi/L — at or above that, EPA recommends fixing the home; between 2 and 4 pCi/L, EPA recommends considering a fix. EPA does not identify any radon level as risk-free, so the goal is to get the concentration as low as reasonably achievable.
Can I just open windows or seal the cracks?
Ventilation can lower a reading temporarily, and sealing cracks helps a mitigation system work better — but neither is a fix on its own. Sealing without an active system just slows entry, and windows are not a long-term strategy. Active sub-slab depressurization is the standard remedy.
How long does a radon mitigation system take to install?
Installation on a typical single-family home is generally a matter of hours, not days, depending on foundation type and the routing of the vent pipe. The confirming post-mitigation test is what sets the total timeline, since it needs its own measurement window.
Does radon go away on its own?
No. Radon is produced continuously by the decay of uranium in the soil under and around the house, so the source doesn’t run out. Levels fluctuate with weather and season, which is why a low follow-up reading in a different month doesn’t cancel a high one.
Do I need to fix radon before selling my house?
That depends on your buyer, your contract, and state disclosure practice — this isn’t legal advice. Practically, radon comes up often in inspections, and a documented mitigation system with a post-mitigation test result is usually easier to hand a buyer than an unresolved high reading.
Radon test came back high? Confirm the number, then fix it. Call Environmental Services of America at (770) 758-2027 to talk through radon testing and mitigation for your home in Athens, Bogart, and the surrounding North Georgia area. Request a quote online anytime.
By D.K.H. · Environmental Services of America (ES America) · Last updated July 2026