What EPA's radon map says about Highland County
Highland County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Highland County sits at the 68th percentile nationally for radon potential — above 68 of every 100 rated counties.
Where Highland County sits nationally
About 2,348 people live in Highland County, Virginia, spread over 415.163 square miles. Averaged across its land area, Highland County runs about 6 people per square mile. Among counties sharing Highland County's EPA zone, it outranks 5% of them by population. Geologically, Highland County is grouped into EPA Region 3 alongside 244 other counties that share its rock and soil setting.
What this actually means for a house in Highland County
Highland 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. Being in Zone 1 raises the odds Highland County homes test above the action level, but it does not mean any specific house does — EPA recommends every home be tested, in every zone, because the only way to know is to test.
If Highland County tests above the action level
Mitigation cost doesn't depend on Highland County's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.
Find Virginia's state radon program
Highland County's test kit answers today; a Airthings radon monitor keeps answering for Highland 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
Highland County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.