Is Sitka City and Borough, AK a radon risk area?

Sitka City and Borough is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. That puts Sitka City and Borough in the 5th percentile nationally for radon potential — higher than 5% of the counties EPA has rated.

How Sitka City and Borough compares

About 8,355 people live in Sitka City and Borough, Alaska, spread over 2,870.201 square miles. Population density there runs about 3 people per square mile. Rank 868 by population within its EPA zone puts Sitka City and Borough at the 16th percentile among zone peers. Sitka City and Borough falls in EPA Radon Region 10, one of 142 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, Sitka City and Borough's Zone 3 prediction is the low end of the scale. A Zone 3 rating means Sitka City and Borough'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.

If Sitka City and Borough tests above the action level

Nothing about Sitka City and Borough'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 Alaska's state radon program

Sitka City and Borough's test kit answers today; a Airthings radon monitor keeps answering for Sitka City and Borough 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.