Short answer: Radon is common in Morris County. NJDEP rates 20 Morris County municipalities as Tier 1, its highest-potential category, and all the rest as Tier 2. No town in the county is in the lowest tier. Testing is easy, and when levels are high, mitigation systems are a routine fix.
What the tiers mean
| NJDEP tier | Share of tested homes at or above 4 pCi/L |
|---|---|
| Tier 1 (high) | 25% or more |
| Tier 2 (moderate) | 5% to 24% |
| Tier 3 (low) | Under 5% |
Tier 1 towns in Morris County
Chester Borough, Chester Township, Dover, Harding, Jefferson, Kinnelon, Long Hill, Mendham Borough, Mendham Township, Mine Hill, Morris Plains, Morris Township, Morristown, Mount Olive, Randolph, Riverdale, Roxbury, Victory Gardens, Washington Township and Wharton.
Every other Morris County town, including Boonton, Mountain Lakes, Montville, Parsippany and Denville, is Tier 2. A town’s tier describes its potential, not your house, so any home can test high or low.
The number that matters: 4 pCi/L
The U.S. EPA recommends fixing a home when radon is at or above 4 picocuries per liter. In New Jersey, radon testing and mitigation must be done by NJDEP-certified professionals.
Radon during a home sale
- Buyers commonly include a radon test with the home inspection, using a short-term test over a few days.
- If the result is high, buyers and sellers usually negotiate installation of a mitigation system or a credit.
- Sellers with an existing system should share its records and a recent test result.
How mitigation works
The most common fix is a sub-slab depressurization system: a pipe and fan that pull radon from beneath the foundation and vent it above the roof. A follow-up test confirms it works.
Buying in the area? See our guides to living in Boonton and lake communities, and avoid these common buyer mistakes.
This article is general information, not legal or tax advice. Rules change and can vary by town, so confirm details with your attorney, accountant or the agency named before you act.
Frequently asked questions
Is radon common in Morris County, NJ?
Yes. NJDEP rates 20 Morris County towns Tier 1 for high radon potential and the rest Tier 2.
What radon level requires mitigation?
The EPA recommends mitigation at or above 4 pCi/L.
Who can test for radon in New Jersey?
Radon testing and mitigation in NJ must be done by NJDEP-certified professionals.
Can radon stop a home sale?
Rarely. High results are usually resolved with a mitigation system or a negotiated credit.
Sources
Talk to the MorrisAgent Team
Have questions about radon in a home you are buying or selling? Call (973) 200-4800, email [email protected], or stop by our office at 518 Main Street, Suite 102, Boonton. No pressure, and no surprises.