What EPA's radon map says about Mifflin County

Mifflin 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 89th percentile for radon potential — Mifflin County outranks 89% of every county EPA has rated.

Mifflin County by the numbers

About 45,935 people live in Mifflin County, Pennsylvania, spread over 411.037 square miles. Averaged across its land area, Mifflin County runs about 112 people per square mile. Among counties sharing Mifflin County's EPA zone, it outranks 68% of them by population. Geologically, Mifflin County is grouped into EPA Region 3 alongside 244 other counties that share its rock and soil setting.

What this actually means for a house in Mifflin County

Fixing a home becomes an EPA recommendation past 4 pCi/L, and that is precisely the side of the line Mifflin County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. Being in Zone 1 raises the odds Mifflin County homes test above the action level, but it does not mean any specific house does — EPA recommends every home be tested, in every zone, because the only way to know is to test.

Next steps for a home in Mifflin County

Mitigation cost doesn't depend on Mifflin 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 Pennsylvania's state radon program

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

More on how this number was built

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. Whatever zone Mifflin County carries, the zone explainer covers what it does and doesn't tell you about any one house.