Grundy County, TN radon potential

EPA's own radon map rates Grundy County zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. Nationally, Grundy County ranks higher in radon potential than 10% of rated counties (the 10th percentile).

Where Grundy County sits nationally

Grundy County, Tennessee is home to about 14,148 people across 360.444 square miles. Averaged across its land area, Grundy County runs about 39 people per square mile. Within its own EPA zone, Grundy County is bigger by population than 29% of the counties that share it. Geologically, Grundy County is grouped into EPA Region 4 alongside 735 other counties that share its rock and soil setting.

Zone vs. an actual test

Grundy County's predicted average sits below the national indoor average of about 1.3 pCi/L, well under EPA's 4 pCi/L action level. Don't read Zone 3 as a pass for Grundy County — EPA's guidance to test every home makes no exception for counties predicted low.

Next steps for a home in Grundy 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 Grundy County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Grundy 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 Grundy County's figures come from

Grundy County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.