You failed a radon test. Here’s exactly what to do — and what not to.

Step 1 — Read your number without flinching

EPA recommends action at 4 pCi/L and above and suggests considering action between 2 and 4. Radon risk is cumulative over years of exposure — EPA identifies radon as the leading cause of lung cancer among people who have never smoked — which is precisely why the right response is planned action, not same-day panic. A 6 is not a 60, and even a 60 is an engineering problem with a known solution.

Step 2 — Decide whether a second test earns its delay

Short-term tests are snapshots, and radon fluctuates with weather and season — if a storm or a hard freeze sat over the test, that alone can explain a reading that surprised you. Before paying for a retest, it is worth checking which direction each test condition pushes a reading, and what the number still establishes — several of these situations bias a result downward, which means a second test may confirm the first rather than rescue you from it. So when does confirming make sense?

• No deadline, result between 2 and 8: a second short-term test (average the two) or a long-term test is reasonable diligence before spending money.
• Result well above 8: confirmation rarely changes the answer. Most households move straight to quotes.
• Inside a transaction: the contract clock usually decides for you — a written mitigation quote resolves negotiations faster than a retest standoff, and the test that matters was likely performed by a licensed measurement professional already.

Step 3 — If you’re in a deal: the 72-hour playbook

1. Share the report, not adjectives. Send the actual result to your agent and attorney the day it lands; Illinois transactions run on short inspection and attorney-review windows.
2. Get a real quote fast. A written quote converts “radon problem” into a line item — typically low four figures — that parties can split, credit, or absorb.
3. Negotiate one of three outcomes: seller installs before closing (with a verification retest), seller credits the quoted amount, or buyer accepts and handles it after closing. All three are legitimate; Illinois requires disclosure of known results, and leaves the remedy to the parties.

Step 4 — Understand the fix you’re buying

The standard system — active sub-slab depressurization — pulls soil gas from beneath the foundation and vents it above the roof, powered by a quiet in-line fan that runs continuously. Installation is usually one day. Two things are normally checked afterwards: a manometer on the pipe, which shows a pressure difference exists across the fan, and a post-mitigation radon test, which reports the level over the period it ran for. Neither one verifies the installation, and the manometer is not a measurement of what anybody breathes. Details: how mitigation systems work and what they cost.

Step 5 — Hire licensed, verify independently

Illinois requires radon mitigation professionals to hold an IEMA-OHS license. Whoever you hire — through us or anywhere else — ask for the license number and check it against the state’s listings. Then compare quotes on design (suction points, routing, fan, warranty, included retest), not just the bottom line. Our licensing guide shows exactly what to verify, and the proposal review worksheet puts two or three bids side by side on those same fields so a cheaper number is visibly cheaper for a reason.

If the order of all this is what’s unclear rather than any single step, the action plan sequences confirming the reading, gathering quotes, and retesting afterwards into dated steps you can work through instead of holding in your head.

Whatever you decide, keep the report. The radon result record saves this result, the laboratory, the device, and any work that follows to one printable sheet on your own device — which is what makes a second test years from now comparable, and what a buyer’s surveyor will ask for.

Before you start collecting numbers, it is worth knowing who is actually allowed to produce them. Finding and verifying a radon professional sets out which body credentials this work in each state we publish for, why the licence rather than the driving distance decides who may do the job, and the five questions that separate a comparable quote from a cheap one.