Potter County, SD: EPA's radon zone, explained

EPA's own radon map rates Potter County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Potter County sits at the 68th percentile nationally for radon potential — above 68 of every 100 rated counties.

Potter County by the numbers

Potter County, South Dakota is home to about 2,402 people across 861.138 square miles. Population density there runs about 3 people per square mile. By population, Potter County is the 1007th largest of every county sharing its EPA zone — the 5th percentile by population within that zone. Potter County falls in EPA Radon Region 8, one of 291 counties nationally EPA assigns to that same geologic province.

Zone vs. an actual test

Outdoor air nationally averages about 0.4 pCi/L, indoor air about 1.3 pCi/L — Potter County's Zone 1 prediction clears both of those and EPA's fix-it threshold besides. That doesn't mean every Potter 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 Potter County

For a Potter County homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find South Dakota's state radon program

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