What EPA's radon map says about Douglas County

EPA's own radon map rates Douglas County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Douglas County sits at the 99th percentile nationally for radon potential — above 99 of every 100 rated counties.

Douglas County by the numbers

About 601,158 people live in Douglas County, Nebraska, spread over 326.54 square miles. That works out to roughly 1,841 people per square mile. Among counties sharing Douglas County's EPA zone, it outranks 97% of them by population. Geologically, Douglas County is grouped into EPA Region 7 alongside 411 other counties that share its rock and soil setting.

Zone vs. an actual test

Where the national indoor average runs about 1.3 pCi/L, Douglas County's Zone 1 rating puts its predicted county average above EPA's 4 pCi/L action level itself. EPA's guidance doesn't change because of a Zone 1 label: test the house. What changes is the reason to not put it off in Douglas County specifically.

Testing and mitigation in Douglas County

Mitigation cost doesn't depend on Douglas 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 Nebraska's state radon program

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

More on how this number was built

Douglas County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.