What EPA's radon map says about Blaine County

Blaine County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Blaine County sits at the 84th percentile nationally for radon potential — above 84 of every 100 rated counties.

Blaine County by the numbers

About 25,261 people live in Blaine County, Idaho, spread over 2,637.738 square miles. Population density there runs about 10 people per square mile. Among counties sharing Blaine County's EPA zone, it outranks 52% of them by population. Blaine County falls in EPA Radon Region 10, one of 142 counties nationally EPA assigns to that same geologic province.

Zone vs. an actual test

Where the national indoor average runs about 1.3 pCi/L, Blaine County's Zone 1 rating puts its predicted county average above EPA's 4 pCi/L action level itself. Some Blaine 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 Blaine County

Mitigation cost doesn't depend on Blaine County's zone — it depends on the house's foundation. A typical system runs $800–$2,500 (about $1,200 typical), and testing first is what tells you whether that's needed at all.

Find Idaho's state radon program

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

More on how this number was built

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