Is Putnam County, NY a radon risk area?

EPA's own radon map rates Putnam County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Rank it against the rest of the country and Putnam County lands in the 94th percentile for radon potential.

Putnam County by the numbers

About 98,409 people live in Putnam County, New York, spread over 230.252 square miles. Population density there runs about 427 people per square mile. Rank 198 by population within its EPA zone puts Putnam County at the 81st percentile among zone peers. Geologically, Putnam County is grouped into EPA Region 2 alongside 82 other counties that share its rock and soil setting.

What this actually means for a house in Putnam County

Putnam County's predicted average sits above EPA's own action level of 4 pCi/L — the concentration at which EPA recommends fixing a home — versus a national average around 1.3 pCi/L indoors and 0.4 pCi/L outdoors. A Zone 1 rating means testing is worth doing sooner rather than later, but it is still county-wide average, not a reading for any single house — some homes in Putnam County will test well under the action level, and EPA's guidance is to test regardless of zone.

Testing and mitigation in Putnam County

Nothing about Putnam 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 York's state radon program

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

More on how this number was built

The methodology guide shows exactly which EPA and Census sources feed Putnam County's numbers. Whatever zone Putnam County carries, the zone explainer covers what it does and doesn't tell you about any one house.