Buena Vista County, IA: EPA's radon zone, explained

Buena Vista County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Nationally that's the 82nd percentile for radon potential — Buena Vista County outranks 82% of every county EPA has rated.

How Buena Vista County compares

Buena Vista County, Iowa is home to about 20,816 people across 574.899 square miles. Population density there runs about 36 people per square mile. By population, Buena Vista County is the 560th largest of every county sharing its EPA zone — the 47th percentile by population within that zone. EPA's geology-based Region 7 groups Buena Vista County with 411 other counties nationally sharing its underlying rock and soil profile.

What this actually means for a house in Buena Vista County

Where the national indoor average runs about 1.3 pCi/L, Buena Vista County's Zone 1 rating puts its predicted county average above EPA's 4 pCi/L action level itself. 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 Buena Vista County will test well under the action level, and EPA's guidance is to test regardless of zone.

If Buena Vista County tests above the action level

For a Buena Vista 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 Iowa's state radon program

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

Where Buena Vista County's figures come from

The methodology guide shows exactly which EPA and Census sources feed Buena Vista County's numbers. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.