Is Grant Parish, LA a radon risk area?

EPA's own radon map rates Grant Parish zone 3 - low potential, predicting a county-wide average indoor level below 2 pCi/L. That puts Grant Parish in the 15th percentile nationally for radon potential — higher than 15% of the counties EPA has rated.

Grant Parish by the numbers

About 22,109 people live in Grant Parish, Louisiana, spread over 643.75 square miles. Averaged across its land area, Grant Parish runs about 34 people per square mile. Rank 576 by population within its EPA zone puts Grant Parish at the 44th percentile among zone peers. EPA's geology-based Region 6 groups Grant Parish with 502 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

A Zone 3 county like Grant Parish is predicted closer to the 0.4 pCi/L typical outdoors than to EPA's 4 pCi/L action level. A Zone 3 label describes Grant Parish's average, not any one basement or slab in it — testing is still the only way an individual homeowner actually finds out.

If Grant Parish tests above the action level

Nothing about Grant Parish'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 Louisiana's state radon program

Grant Parish's test kit answers today; a Airthings radon monitor keeps answering for Grant Parish over time. Affiliate link, RadonZoneCheck earns a commission there, at no extra cost to you. Code RADONZONE-10OFF takes 10% off at checkout.

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. The guide to what a radon zone actually means covers why testing matters in every zone, not just Zone 1.