Richland County, WI radon potential

EPA places Richland 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. Nationally that's the 80th percentile for radon potential — Richland County outranks 80% of every county EPA has rated.

Richland County by the numbers

Richland County, Wisconsin is home to about 17,123 people across 586.15 square miles. Averaged across its land area, Richland County runs about 29 people per square mile. Within its own EPA zone, Richland County is bigger by population than 42% of the counties that share it. Geologically, Richland 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 Richland County

Outdoor air nationally averages about 0.4 pCi/L, indoor air about 1.3 pCi/L — Richland County's Zone 1 prediction clears both of those and EPA's fix-it threshold besides. 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 Richland County specifically.

Testing and mitigation in Richland 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 Wisconsin's state radon program

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