Is Kings County, CA a radon risk area?

EPA's own radon map rates Kings County zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. Nationally, Kings County ranks higher in radon potential than 28% of rated counties (the 28th percentile).

Where Kings County sits nationally

About 154,913 people live in Kings County, California, spread over 1,390.972 square miles. Population density there runs about 111 people per square mile. Rank 164 by population within its EPA zone puts Kings County at the 84th percentile among zone peers. Kings County falls in EPA Radon Region 9, one of 95 counties nationally EPA assigns to that same geologic province.

Zone vs. an actual test

Well clear of both the 1.3 pCi/L national indoor average and EPA's 4 pCi/L action level, Kings County's Zone 3 prediction is the low end of the scale. Don't read Zone 3 as a pass for Kings County — EPA's guidance to test every home makes no exception for counties predicted low.

If Kings County tests above the action level

Nothing about Kings County's EPA zone changes the mitigation number: $800–$2,500 nationally (around $1,200 typical), set by the house's foundation rather than the county it sits in — and only relevant once a test actually clears 4 pCi/L.

Find California's state radon program

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

Every figure on this page traces to EPA's own Map of Radon Zones and Census data, documented in the methodology guide. If you're unsure why a low zone still deserves a test, the zone explainer covers that directly.