Auglaize County, OH: EPA's radon zone, explained

EPA places Auglaize 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. That puts Auglaize County in the 89th percentile nationally for radon potential — higher than 89% of the counties EPA has rated.

Where Auglaize County sits nationally

Auglaize County, Ohio is home to about 45,922 people across 401.388 square miles. That works out to roughly 114 people per square mile. By population, Auglaize County is the 341st largest of every county sharing its EPA zone — the 68th percentile by population within that zone. Auglaize County falls in EPA Radon Region 5, one of 524 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 Auglaize County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. 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 Auglaize County will test well under the action level, and EPA's guidance is to test regardless of zone.

If Auglaize County tests above the action level

For a Auglaize 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 Ohio's state radon program

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

Where Auglaize County's figures come from

Auglaize County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. Whatever zone Auglaize County carries, the zone explainer covers what it does and doesn't tell you about any one house.