Is Pierce County, ND a radon risk area?

EPA's own radon map rates Pierce County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Rank it against the rest of the country and Pierce County lands in the 69th percentile for radon potential.

Pierce County by the numbers

About 3,853 people live in Pierce County, North Dakota, spread over 1,018.285 square miles. Averaged across its land area, Pierce County runs about 4 people per square mile. Rank 957 by population within its EPA zone puts Pierce County at the 10th percentile among zone peers. Geologically, Pierce County is grouped into EPA Region 8 alongside 290 other counties that share its rock and soil setting.

Why the zone isn't the answer by itself

Fixing a home becomes an EPA recommendation past 4 pCi/L, and that is precisely the side of the line Pierce County's Zone 1 prediction lands on, well above the roughly 1.3 pCi/L most US homes average. A Zone 1 rating means testing is worth doing sooner rather than later, but it is still county-wide average, not a reading for any single house — some homes in Pierce County will test well under the action level, and EPA's guidance is to test regardless of zone.

Next steps for a home in Pierce County

Nothing about Pierce 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

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