Shiawassee County, MI radon potential

EPA places Shiawassee 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. Rank it against the rest of the country and Shiawassee County lands in the 57th percentile for radon potential.

How Shiawassee County compares

Shiawassee County, Michigan is home to about 67,982 people across 531.126 square miles. Averaged across its land area, Shiawassee County runs about 128 people per square mile. Within its own EPA zone, Shiawassee County is bigger by population than 74% of the counties that share it. EPA's geology-based Region 5 groups Shiawassee County with 523 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Shiawassee 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). A Zone 2 rating is a moderate county-wide average, not a guarantee about any one house in Shiawassee County — testing is the only way to know an individual home's actual level.

Next steps for a home in Shiawassee 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 Michigan's state radon program

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

Where Shiawassee 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 Shiawassee County carries, the zone explainer covers what it does and doesn't tell you about any one house.