What EPA's radon map says about Grenada County

Grenada County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. That puts Grenada County in the 14th percentile nationally for radon potential — higher than 14% of the counties EPA has rated.

Where Grenada County sits nationally

About 20,931 people live in Grenada County, Mississippi, spread over 422.113 square miles. Averaged across its land area, Grenada County runs about 50 people per square mile. Among counties sharing Grenada County's EPA zone, it outranks 42% of them by population. Geologically, Grenada County is grouped into EPA Region 4 alongside 735 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

Grenada County's Zone 3 prediction undercuts the roughly 1.3 pCi/L most US homes average, nowhere near EPA's 4 pCi/L threshold for recommending mitigation. A Zone 3 rating means Grenada County's county-wide average is predicted low, but EPA is explicit that a meaningful share of homes in low-potential zones still test above the action level — a low zone is not a reason to skip testing.

Next steps for a home in Grenada County

Mitigation cost doesn't depend on Grenada 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 Mississippi's state radon program

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

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