San Jacinto County, TX: EPA's radon zone, explained

San Jacinto County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. Rank it against the rest of the country and San Jacinto County lands in the 17th percentile for radon potential.

Where San Jacinto County sits nationally

San Jacinto County, Texas is home to about 29,326 people across 569.244 square miles. Averaged across its land area, San Jacinto County runs about 52 people per square mile. By population, San Jacinto County is the 488th largest of every county sharing its EPA zone — the 53rd percentile by population within that zone. San Jacinto County falls in EPA Radon Region 6, one of 503 counties nationally EPA assigns to that same geologic province.

Why the zone isn't the answer by itself

Well clear of both the 1.3 pCi/L national indoor average and EPA's 4 pCi/L action level, San Jacinto County's Zone 3 prediction is the low end of the scale. A Zone 3 rating means San Jacinto 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.

Testing and mitigation in San Jacinto County

For a San Jacinto County homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find Texas's state radon program

For San Jacinto County, an ongoing number beats a one-time test - a Airthings radon monitor tracks San Jacinto County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

Where San Jacinto County's figures come from

The methodology guide shows exactly which EPA and Census sources feed San Jacinto County's numbers. Whatever zone San Jacinto County carries, the zone explainer covers what it does and doesn't tell you about any one house.