Is Santa Cruz County, CA a radon risk area?

EPA's own radon map rates Santa Cruz County zone 2 - moderate potential, predicting a county-wide average indoor level between 2 and 4 pCi/L. Nationally that's the 63rd percentile for radon potential — Santa Cruz County outranks 63% of every county EPA has rated.

Where Santa Cruz County sits nationally

About 262,406 people live in Santa Cruz County, California, spread over 445.106 square miles. Population density there runs about 590 people per square mile. Rank 91 by population within its EPA zone puts Santa Cruz County at the 91st percentile among zone peers. Santa Cruz County falls in EPA Radon Region 9, one of 95 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Santa Cruz County

Santa Cruz County's Zone 2 prediction clears the 1.3 pCi/L national indoor average without reaching EPA's own 4 pCi/L point for recommending a fix. Middle-of-the-pack doesn't mean risk-free for any one Santa Cruz County address — a moderate county average still leaves individual homes to test either side of it.

Next steps for a home in Santa Cruz County

Nothing about Santa Cruz 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

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