Calhoun County, AR Radon Zone Data

Calhoun County, AR radon potential

Calhoun County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. Nationally that's the 3rd percentile for radon potential — Calhoun County outranks 3% of every county EPA has rated.

How Calhoun County compares

Calhoun County, Arkansas is home to about 4,690 people across 628.601 square miles. Averaged across its land area, Calhoun County runs about 7 people per square mile. Within its own EPA zone, Calhoun County is bigger by population than 8% of the counties that share it. Geologically, Calhoun County is grouped into EPA Region 6 alongside 502 other counties that share its rock and soil setting.

What this actually means for a house in Calhoun County

At Zone 3, Calhoun County's predicted county average is under the national indoor average (~1.3 pCi/L) and well below EPA's 4 pCi/L action level — outdoor air nationally runs about 0.4 pCi/L for comparison. Low doesn't mean zero: EPA's own data shows homes in Zone 3 counties like Calhoun County testing above the action level often enough that skipping a test isn't the safe assumption.

If Calhoun County tests above the action level

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 Arkansas's state radon program

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

Where Calhoun 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. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.