What EPA's radon map says about San Patricio County

EPA's own radon map rates San Patricio County zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. That puts San Patricio County in the 24th percentile nationally for radon potential — higher than 24% of the counties EPA has rated.

Where San Patricio County sits nationally

About 71,467 people live in San Patricio County, Texas, spread over 693.32 square miles. That works out to roughly 103 people per square mile. Among counties sharing San Patricio County's EPA zone, it outranks 74% of them by population. Geologically, San Patricio County is grouped into EPA Region 6 alongside 502 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

San Patricio County's predicted average sits below the national indoor average of about 1.3 pCi/L, well under EPA's 4 pCi/L action level. Even at Zone 3, San Patricio County homes are not guaranteed a low reading — zone is a county-wide average, and EPA recommends testing every home regardless of zone.

Testing and mitigation in San Patricio County

Mitigation cost doesn't depend on San Patricio 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 Texas's state radon program

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

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