You’re under contract on a home in New Jersey. The inspection goes smoothly. Then the radon test results come back — and the number is higher than 4.0 pCi/L. Your stomach drops.
Take a breath. A failed radon test does not mean the deal is dead. It doesn’t mean the home is unsafe to buy. What it means is that you now have information, and information gives you options. Here’s exactly what to do, step by step.
Step 1: Understand What Your Number Actually Means
The EPA’s action level for radon is 4.0 picocuries per liter (pCi/L). If your test came back at or above this level, the EPA recommends mitigation. But context matters:
- 4.0 – 8.0 pCi/L — Elevated, but very common in New Jersey. Highly treatable.
- 8.0 – 20.0 pCi/L — Definitely needs mitigation, but still routinely resolved with a standard system.
- 20.0+ pCi/L — Higher than average, but not a reason to panic. Professional mitigation systems can reduce levels by up to 99%.
The average indoor radon level in the U.S. is about 1.3 pCi/L, so anything significantly above that warrants action. New Jersey has particularly active radon geology — parts of the state, especially in the north and central regions, see elevated readings with regularity. A high number is common. It is not unusual, and it is fixable.
Step 2: Don’t Make Any Decisions Until You Verify the Test
Before negotiating or walking away, consider requesting a second test — especially if the original was a short-term test (48-hour charcoal canister). Short-term tests are a snapshot, and results can vary based on weather, time of year, and whether windows were left open. A second short-term test or a longer 90-day test will give you a more accurate picture.
A licensed radon measurement professional can conduct a verified retest under controlled conditions. In real estate transactions, it’s common for both parties to agree to a follow-up test before proceeding with negotiations.
Step 3: Know Your Options in the Transaction
Once you have confirmed elevated radon levels, you typically have three paths forward:
Option A — Negotiate mitigation as a seller concession. This is the most common resolution. The buyer (you) requests that the seller install a radon mitigation system prior to closing, or provides a credit for the cost of installation. In New Jersey, mitigation typically costs between $800 and $2,500 depending on the home’s foundation type and complexity.
Option B — Handle mitigation yourself after closing. If you’re getting a great deal on the home, or the seller refuses to negotiate, you can close on the home and have the system installed afterward. This gives you full control over the contractor and the system quality.
Option C — Walk away using your contingency. If your purchase contract includes a radon contingency (and it should), and the seller refuses to negotiate or address the issue, you can exit the deal and receive your deposit back. This is a last resort — in most cases, mitigation is straightforward enough that both sides find a way forward.
Step 4: Understand What Mitigation Actually Involves
If you’ve never dealt with radon before, the idea of “mitigation” can sound intimidating. It isn’t. A sub-slab depressurization system — the most common solution for New Jersey homes — involves:
- A small suction point drilled through the basement floor or slab
- A PVC pipe routed through the home or along an exterior wall
- A continuously running fan that pulls radon from beneath the foundation and vents it safely outside
Installation typically takes 4 to 8 hours. The system is quiet, low-maintenance, and can reduce radon levels by up to 99%. Most homeowners are barely aware it’s running after the first few days.
After installation, a follow-up test is conducted (usually 24–48 hours later) to confirm the system is working. Levels almost always drop significantly below the 4.0 pCi/L action level — and often down to 1.0 pCi/L or lower.
Step 5: Choose the Right Mitigation Contractor
If you’re handling this as part of a real estate transaction, timing matters. Closing deadlines are real, and you need a contractor who can move quickly and provide documentation that satisfies your real estate attorney and lender.
When selecting a radon mitigation company in New Jersey, look for:
- NRPP or NRSB certification — These are the nationally recognized credentials for radon mitigation professionals
- NJ state licensing — New Jersey requires radon contractors to be licensed through the Department of Environmental Protection
- Post-mitigation testing included — Any reputable company will verify results after installation
- Written warranty — Look for a guarantee that the system will bring levels below 4.0 pCi/L
At Jersey Radon, we’re fully licensed and certified in New Jersey, and we understand the urgency of real estate timelines. We can typically schedule mitigation within days of your call and provide all documentation needed for closing.
Step 6: Test Again After Moving In
Even after a mitigation system is installed and verified, we recommend conducting a new radon test within the first year of living in the home — especially after you’ve settled in and normal living patterns are established (windows and doors in regular use, HVAC running seasonally, etc.).
After that, testing every two years is a good habit. Radon systems are low-maintenance but not maintenance-free. An annual visual inspection of the fan and a periodic glance at the manometer (the U-tube pressure gauge on your pipe) will tell you the system is running properly.
The Bottom Line
A radon test failure during a home purchase in New Jersey is not a catastrophe — it’s a common and very solvable problem. Hundreds of New Jersey homeowners go through this exact process every year and end up in safe, protected homes with mitigation systems that work quietly and effectively for decades.
What matters most is not panicking, understanding your numbers, and taking the right next steps with the right professionals.
If your NJ home test came back elevated and you need answers fast, Jersey Radon is here to help. We serve all of New Jersey and can often schedule an assessment within 24 to 48 hours.
