Montgomery County, MO radon potential

EPA places Montgomery County in Zone 2 - Moderate Potential — a predicted county-wide average indoor radon level between 2 and 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Nationally, Montgomery County ranks higher in radon potential than 41% of rated counties (the 41st percentile).

Where Montgomery County sits nationally

Montgomery County, Missouri is home to about 11,511 people across 535.047 square miles. Population density there runs about 22 people per square mile. Within its own EPA zone, Montgomery County is bigger by population than 23% of the counties that share it. Montgomery County falls in EPA Radon Region 7, one of 412 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Montgomery County

Montgomery County's predicted average falls between EPA's 4 pCi/L action level and the national indoor average of about 1.3 pCi/L (outdoor air runs roughly 0.4 pCi/L). Montgomery County's Zone 2 rating sits in the middle nationally; EPA's guidance is unchanged by that — test every home regardless of its zone.

If Montgomery 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 Missouri's state radon program

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

Where Montgomery County's figures come from

Montgomery County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. Whatever zone Montgomery County carries, the zone explainer covers what it does and doesn't tell you about any one house.