New Jersey Radon Map, Levels & Testing Guide
Browse the 21 listed county pages surfaced for New Jersey. Open a listed county to compare its EPA zone, source caveats, testing meaning, and when mitigation pricing becomes worth checking.
High Risk
Moderate
Low Risk
NJDEP Radon Potential Map
Use the NJDEP tier first, then open the county page
New Jersey searches are often map-first, not article-first. NJDEP assigns municipalities to radon-potential tiers, so this page should help a user understand whether a county contains Tier 1 or Tier 2 communities before they decide to test, retest, or price mitigation.
Open NJDEP radon mapTier 1
High-potential municipalities: enough tested homes and a large enough share at or above 4.0 pCi/L to prioritize testing.
Tier 2
Moderate-potential signal. Do not dismiss the home; use the map as context and still test the lowest livable level.
County path
Open a county below for the local evidence read, then use the cost page only after a real result.
Official Evidence in New Jersey
21 of 21 listed counties have official evidence
Open a county page to see the official source context: measurement fields, local burden, state percentile, and the next step for no reading, 2.0-3.9, or 4.0+ pCi/L.
100%
covered
Measured
0
State source
0
CDC source
0
Needs source detail
0
Already Tested
View New Jersey Cost Estimates
If you already have a radon result, skip the directory and move straight to local price guidance.
Understand the Number
2.0 vs 4.0 vs 8.0 pCi/L
Use the parent levels guide if you need the plain-English meaning of a radon result before browsing counties.
Need a Number First
Read the Testing Guide
Use the fastest valid radon test setup before you compare quotes or ask whether mitigation is worth it.
Browse Counties
Jump to the Directory
Open your county to see its EPA zone, testing meaning, and the point where mitigation becomes worth pricing.
Official State Resource
New Jersey radon program and rules
Use the state program link to verify local radon guidance, disclosure language, and contractor credential expectations before you act on an estimate.
Disclosure rule tracked
New Jersey requires radon testing and disclosure for all real estate transactions in Tier 1 counties under the Radon Hazard Subcode.
State licensing required
New Jersey requires certification for radon testers and mitigators through the NJ DEP.
Already tested? Get your itemized mitigation cost estimate.
View New Jersey Mitigation Cost Estimates ->