What EPA's radon map says about Beadle County

Beadle County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Nationally, Beadle County ranks higher in radon potential than 81% of rated counties (the 81st percentile).

How Beadle County compares

About 19,459 people live in Beadle County, South Dakota, spread over 1,258.698 square miles. Averaged across its land area, Beadle County runs about 15 people per square mile. Among counties sharing Beadle County's EPA zone, it outranks 45% of them by population. Beadle County falls in EPA Radon Region 8, one of 291 counties nationally EPA assigns to that same geologic province.

Why the zone isn't the answer by itself

Where the national indoor average runs about 1.3 pCi/L, Beadle County's Zone 1 rating puts its predicted county average above EPA's 4 pCi/L action level itself. 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 Beadle County specifically.

Next steps for a home in Beadle County

Mitigation cost doesn't depend on Beadle County's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.

Find South Dakota's state radon program

Beadle County's test kit answers today; a Airthings radon monitor keeps answering for Beadle County over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

More on how this number was built

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.