Tazewell County, IL radon potential

EPA places Tazewell County in Zone 1 - Highest Potential — a predicted county-wide average indoor radon level above 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Rank it against the rest of the country and Tazewell County lands in the 95th percentile for radon potential.

Tazewell County by the numbers

Tazewell County, Illinois is home to about 129,821 people across 646.486 square miles. Population density there runs about 201 people per square mile. Within its own EPA zone, Tazewell County is bigger by population than 86% of the counties that share it. Geologically, Tazewell County is grouped into EPA Region 5 alongside 523 other counties that share its rock and soil setting.

What this actually means for a house in Tazewell County

Tazewell 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. EPA's guidance doesn't change because of a Zone 1 label: test the house. What changes is the reason to not put it off in Tazewell County specifically.

Testing and mitigation in Tazewell 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 Illinois's state radon program

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

Tazewell 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.