Bartholomew County, IN radon potential

Bartholomew County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Nationally, Bartholomew County ranks higher in radon potential than 93% of rated counties (the 93rd percentile).

Bartholomew County by the numbers

Bartholomew County, Indiana is home to about 84,741 people across 406.94 square miles. Averaged across its land area, Bartholomew County runs about 208 people per square mile. Within its own EPA zone, Bartholomew County is bigger by population than 80% of the counties that share it. EPA's geology-based Region 5 groups Bartholomew County with 523 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Bartholomew County's predicted average sits above EPA's own action level of 4 pCi/L — the concentration at which EPA recommends fixing a home — versus a national average around 1.3 pCi/L indoors and 0.4 pCi/L outdoors. Some Bartholomew County homes will test comfortably under the action level despite the county's Zone 1 rating — the only way to know which kind of home you have is an actual test.

If Bartholomew 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 Indiana's state radon program

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