Is Passaic County, NJ a radon risk area?

Passaic County is mapped as Zone 2 - Moderate Potential by EPA — meaning the county-wide average indoor level is predicted between 2 and 4 pCi/L. Nationally that's the 64th percentile for radon potential — Passaic County outranks 64% of every county EPA has rated.

Where Passaic County sits nationally

About 526,597 people live in Passaic County, New Jersey, spread over 186.132 square miles. That works out to roughly 2,829 people per square mile. Rank 48 by population within its EPA zone puts Passaic County at the 95th percentile among zone peers. Geologically, Passaic County is grouped into EPA Region 2 alongside 82 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

EPA's Zone 2 rating for Passaic County sits below its own 4 pCi/L action level but above the national indoor average of about 1.3 pCi/L. Nothing about a Zone 2 label lowers the case for testing in Passaic County — EPA recommends it in every zone, moderate included.

Testing and mitigation in Passaic County

Nothing about Passaic County's EPA zone changes the mitigation number: $800–$2,500 nationally (around $1,200 typical), set by the house's foundation rather than the county it sits in — and only relevant once a test actually clears 4 pCi/L.

Find New Jersey's state radon program

Passaic County's test kit answers today; a Airthings radon monitor keeps answering for Passaic County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

More on how this number was built

Passaic County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.