Is Warren County, VA a radon risk area?

Warren County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. That puts Warren County in the 88th percentile nationally for radon potential — higher than 88% of the counties EPA has rated.

Warren County by the numbers

About 42,461 people live in Warren County, Virginia, spread over 214.572 square miles. Population density there runs about 198 people per square mile. Rank 361 by population within its EPA zone puts Warren County at the 66th percentile among zone peers. EPA's geology-based Region 3 groups Warren County with 244 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Warren County

Where the national indoor average runs about 1.3 pCi/L, Warren County's Zone 1 rating puts its predicted county average above EPA's 4 pCi/L action level itself. 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 Warren County will test well under the action level, and EPA's guidance is to test regardless of zone.

If Warren County tests above the action level

Nothing about Warren 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 Virginia's state radon program

Warren County's test kit answers today; a Airthings radon monitor keeps answering for Warren 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

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. Whatever zone Warren County carries, the zone explainer covers what it does and doesn't tell you about any one house.