Powhatan County, VA: EPA's radon zone, explained

Powhatan County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Nationally, Powhatan County ranks higher in radon potential than 86% of rated counties (the 86th percentile).

Where Powhatan County sits nationally

Powhatan County, Virginia is home to about 32,392 people across 260.202 square miles. Averaged across its land area, Powhatan County runs about 124 people per square mile. By population, Powhatan County is the 448th largest of every county sharing its EPA zone — the 58th percentile by population within that zone. EPA's geology-based Region 3 groups Powhatan County with 244 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Powhatan 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 Powhatan County will test well under the action level, and EPA's guidance is to test regardless of zone.

Testing and mitigation in Powhatan County

For a Powhatan County homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find Virginia's state radon program

For Powhatan County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Powhatan County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. Code RADONZONE-10OFF takes 10% off at checkout.

Where Powhatan County's figures come from

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