Is Bowman County, ND a radon risk area?

EPA places Bowman County in Zone 1 - Highest Potential — a predicted county-wide average indoor radon level above 4 pCi/L, based on the geology, soil and aerial radioactivity data behind EPA's national map. That puts Bowman County in the 69th percentile nationally for radon potential — higher than 69% of the counties EPA has rated.

Bowman County by the numbers

About 2,886 people live in Bowman County, North Dakota, spread over 1,161.809 square miles. That works out to roughly 2 people per square mile. Rank 985 by population within its EPA zone puts Bowman County at the 8th percentile among zone peers. EPA's geology-based Region 8 groups Bowman County with 290 other counties nationally sharing its underlying rock and soil profile.

Zone vs. an actual test

Bowman County's predicted average sits above EPA's own action level of 4 pCi/L — the concentration at which EPA recommends fixing a home — versus a national average around 1.3 pCi/L indoors and 0.4 pCi/L outdoors. That doesn't mean every Bowman County house tests high — a zone is a county-wide prediction, never a single-home reading — but it's a reason to test sooner rather than let it wait.

Next steps for a home in Bowman County

Nothing about Bowman 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 North Dakota's state radon program

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

Bowman County's zone, rank and region all trace back to named EPA and Census sources — the methodology guide lists exactly which ones. Whatever zone Bowman County carries, the zone explainer covers what it does and doesn't tell you about any one house.