How high is radon potential in your New Jersey town?
Every municipality is classified Tier 1, 2 or 3 by the share of homes that tested at or above the EPA action level of 4 pCi/L. Search your town or tap the map.
150Tier 1 · High
251Tier 2 · Moderate
163Tier 3 · Low
Tier is a town-level statistic, not a reading at your house. NJDEP and the EPA recommend testing every home regardless of tier.
Lowunder 5%Moderate5–24%High25% and above
Thinking about a test? We're certified for radon measurement and do this every week across New Jersey — happy to help or just answer questions: Smart Choice Inspections · (973) 500-3233. No pressure — any certified professional runs the same test.
Radon is a radioactive gas you can't see or smell, produced underground as uranium in bedrock slowly breaks down. It seeps up through soil and enters homes through foundation cracks, sump pits and slab joints.
It is the second-leading cause of lung cancer in the United States — the first among people who never smoked — linked by the EPA to roughly 21,000 deaths a year.
New Jersey's hot spots follow its geology. The Reading Prong, a band of uranium-bearing granite, runs through Sussex, Warren, Hunterdon and Morris counties.
That band is why nearly all of northwestern New Jersey is Tier 1. Coastal and urban areas built on sand, clay and fill generally test far lower.
What the tiers mean
Share of tested homes at or above 4 pCi/L
Tier 1 — High
25%+
of tested homes at or above 4 pCi/L
New homes must be built with radon-resistant construction (N.J.A.C. 5:23-10). Once a town is Tier 1 it stays Tier 1, even if newer readings drop — partly because resistant construction lowers them.
Tier 2 — Moderate
5–24%
of tested homes at or above 4 pCi/L
Elevated homes are common enough that NJDEP recommends testing every house. A 2–7 day test settles it.
Tier 3 — Low
Under 5%
of tested homes at or above 4 pCi/L
Most homes test under the limit — but elevated houses turn up in every tier, including this one.
The tier describes your town's odds, not your house. Two neighbors can test wildly differently.
Testing and fixing it
The quick version
01 · TEST
2 to 7 days, windows closed
A charcoal kit or continuous monitor. In New Jersey, testing done for hire — including for a real-estate transaction — must be performed by a certified radon measurement business.
02 · READ
4 pCi/L is the action level
At or above it, fix the house. Between 2 and 4, fixing is worth considering.
03 · FIX
$800–$2,500, routine work
Sub-slab depressurization: a pipe and fan that vents soil gas above the roof. It brings most homes well under the limit. Mitigation must also be done by a certified business.
04 · TIMING
Test early if you're buying or selling
Results follow the property, and an elevated unmitigated result found mid-transaction is a classic closing snag.
Roster and photos from the NRPP certified professionals directory — the list the New Jersey state radon office refers consumers to — snapshot August 14, 2026. Check the live directory for the current list. New Jersey additionally requires state licensing for radon work; confirm current certification and licensing with anyone you hire.
Official sources
NJDEP Radon Program — certification, guidance, state info line (800) 648-0394
Tier assignments from the NJDEP Radon Tier Assignment Report, supplemented for a small number of municipalities by N.J.A.C. 5:23-10 Appendix 10-A and NJDEP's current municipal testing data (percent of tests ≥ 4 pCi/L, via the NJDEP HCPNJ dataset) applying the state's published tier formula. Informational only — a tier is not a substitute for testing this house. Built by Permit & Parcel, oprasearch.app.
