Cumberland County · NJDEP Radon Potential: Tier 1 — high
NJDEP assigns every New Jersey municipality a radon-potential tier; Tier 1 is the highest, meaning at least 25% of tested homes met or exceeded 4.0 pCi/L. It doesn't mean every house is high — radon varies house to house even on the same street — but it makes testing genuinely important here, and it triggers the state's radon-resistant new-construction requirement (N.J.A.C. 5:23-10).
No certified business is based in Cumberland County itself, but certified firms across New Jersey serve Greenwich Township — browse the full certified list.
NJDEP designates Greenwich Township a Tier 1 municipality — its highest radon-potential classification. In the published NJDEP dataset, 54 homes in Greenwich Township were tested and 28% measured at or above the EPA action level of 4.0 pCi/L. Any individual home can be high or low — testing is the only way to know yours.
Yes. New Jersey's radon hazard subcode (N.J.A.C. 5:23-10) requires radon-resistant construction techniques for new residential construction in Tier 1 municipalities like Greenwich Township, including a gas-permeable layer, vapor barrier, and a vent pipe.
New Jersey law requires radon testing and mitigation businesses to be certified by the NJDEP Radon Program. Certified firms across New Jersey serve Cumberland County. Homeowners may legally test their own home with a kit, but hire a certified tester for a real-estate transaction.
Tell us what you need — we'll connect you with state-certified companies serving your area. No obligation.