Aurora County, SD radon potential

EPA places Aurora 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. Aurora County sits at the 68th percentile nationally for radon potential — above 68 of every 100 rated counties.

How Aurora County compares

Aurora County, South Dakota is home to about 2,752 people across 708.46 square miles. That works out to roughly 4 people per square mile. Within its own EPA zone, Aurora County is bigger by population than 7% of the counties that share it. Aurora 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

Fixing a home becomes an EPA recommendation past 4 pCi/L, and that is precisely the side of the line Aurora County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. Some Aurora County homes will test comfortably under the action level despite the county's Zone 1 rating — the only way to know which kind of home you have is an actual test.

Next steps for a home in Aurora 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 South Dakota's state radon program

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

Where Aurora County's figures come from

The methodology guide shows exactly which EPA and Census sources feed Aurora County's numbers. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.