Warren County, MO radon potential

Warren County is mapped as Zone 2 - Moderate Potential by EPA — meaning the county-wide average indoor level is predicted between 2 and 4 pCi/L. That puts Warren County in the 53rd percentile nationally for radon potential — higher than 53% of the counties EPA has rated.

How Warren County compares

Warren County, Missouri is home to about 38,478 people across 428.596 square miles. Population density there runs about 90 people per square mile. Within its own EPA zone, Warren County is bigger by population than 60% of the counties that share it. EPA's geology-based Region 7 groups Warren County with 411 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Warren County

Neither at the 4 pCi/L action level nor down at the roughly 1.3 pCi/L national indoor norm, Warren County's Zone 2 prediction lands in the gap between the two. Middle-of-the-pack doesn't mean risk-free for any one Warren County address — a moderate county average still leaves individual homes to test either side of it.

Next steps for a home in Warren 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 Missouri's state radon program

For Warren County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Warren 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 Warren County's figures come from

Warren 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.