What EPA's radon map says about Bristol County

Bristol County is mapped as Zone 3 - Low Potential by EPA — meaning the county-wide average indoor level is predicted below 2 pCi/L. Nationally, Bristol County ranks higher in radon potential than 22% of rated counties (the 22nd percentile).

Where Bristol County sits nationally

About 50,145 people live in Bristol County, Rhode Island, spread over 24.132 square miles. Averaged across its land area, Bristol County runs about 2,078 people per square mile. Among counties sharing Bristol County's EPA zone, it outranks 67% of them by population. EPA's geology-based Region 1 groups Bristol County with 58 other counties nationally sharing its underlying rock and soil profile.

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, Bristol County's Zone 3 prediction is the low end of the scale. Don't read Zone 3 as a pass for Bristol County — EPA's guidance to test every home makes no exception for counties predicted low.

Next steps for a home in Bristol County

Mitigation cost doesn't depend on Bristol 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 Rhode Island's state radon program

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