Is Hanson County, SD a radon risk area?

Hanson County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Hanson County sits at the 69th percentile nationally for radon potential — above 69 of every 100 rated counties.

Hanson County by the numbers

About 3,477 people live in Hanson County, South Dakota, spread over 434.582 square miles. Averaged across its land area, Hanson County runs about 8 people per square mile. Rank 969 by population within its EPA zone puts Hanson County at the 9th percentile among zone peers. Hanson 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

Hanson County carries a Zone 1 label because its predicted average clears 4 pCi/L outright — three-plus times the 0.4 pCi/L typical outdoors and above the 1.3 pCi/L most homes see. That doesn't mean every Hanson County house tests high — a zone is a county-wide prediction, never a single-home reading — but it's a reason to test sooner rather than let it wait.

Testing and mitigation in Hanson County

Nothing about Hanson County's EPA zone changes the mitigation number: $800–$2,500 nationally (around $1,200 typical), set by the house's foundation rather than the county it sits in — and only relevant once a test actually clears 4 pCi/L.

Find South Dakota's state radon program

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

More on how this number was built

Hanson 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.