What EPA's radon map says about Seward County

EPA places Seward County in Zone 2 - Moderate Potential — a predicted county-wide average indoor radon level between 2 and 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. Nationally that's the 47th percentile for radon potential — Seward County outranks 47% of every county EPA has rated.

Where Seward County sits nationally

About 21,276 people live in Seward County, Kansas, spread over 639.653 square miles. Averaged across its land area, Seward County runs about 33 people per square mile. Among counties sharing Seward County's EPA zone, it outranks 42% of them by population. Geologically, Seward County is grouped into EPA Region 7 alongside 411 other counties that share its rock and soil setting.

What this actually means for a house in Seward County

Seward County's predicted average falls between EPA's 4 pCi/L action level and the national indoor average of about 1.3 pCi/L (outdoor air runs roughly 0.4 pCi/L). Nothing about a Zone 2 label lowers the case for testing in Seward County — EPA recommends it in every zone, moderate included.

Testing and mitigation in Seward County

Mitigation cost doesn't depend on Seward 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 Kansas's state radon program

Seward County's test kit answers today; a Airthings radon monitor keeps answering for Seward 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

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