Humphreys County, TN radon potential

Humphreys County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Nationally that's the 81st percentile for radon potential — Humphreys County outranks 81% of every county EPA has rated.

Humphreys County by the numbers

Humphreys County, Tennessee is home to about 19,554 people across 530.763 square miles. That works out to roughly 37 people per square mile. Within its own EPA zone, Humphreys County is bigger by population than 45% of the counties that share it. Geologically, Humphreys County is grouped into EPA Region 4 alongside 735 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

Fixing a home becomes an EPA recommendation past 4 pCi/L, and that is precisely the side of the line Humphreys County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. 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 Humphreys County will test well under the action level, and EPA's guidance is to test regardless of zone.

Testing and mitigation in Humphreys County

A short-term test kit is the standard first step and typically costs far less than mitigation itself. If a test comes back at or above 4 pCi/L, a radon mitigation system for a typical home runs roughly $800–$2,500 (around $1,200 for a common single-family install), driven mainly by foundation type, not by county.

Find Tennessee's state radon program

For Humphreys County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Humphreys 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 Humphreys 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 Humphreys County carries, the zone explainer covers what it does and doesn't tell you about any one house.