Is Miner County, SD a radon risk area?

EPA places Miner 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 Miner County lands in the 68th percentile for radon potential.

Where Miner County sits nationally

About 2,303 people live in Miner County, South Dakota, spread over 570.17 square miles. Averaged across its land area, Miner County runs about 4 people per square mile. Rank 1017 by population within its EPA zone puts Miner County at the 5th percentile among zone peers. Geologically, Miner County is grouped into EPA Region 8 alongside 290 other counties that share its rock and soil setting.

Zone vs. an actual test

Miner 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. A Zone 1 rating means testing is worth doing sooner rather than later, but it is still county-wide average, not a reading for any single house — some homes in Miner County will test well under the action level, and EPA's guidance is to test regardless of zone.

If Miner County tests above the action level

Nothing about Miner 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

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

More on how this number was built

Miner County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.