Is Monongalia County, WV a radon risk area?

EPA's own radon map rates Monongalia County zone 1 - highest potential, predicting a county-wide average indoor level above 4 pCi/L. Monongalia County sits at the 94th percentile nationally for radon potential — above 94 of every 100 rated counties.

Monongalia County by the numbers

About 108,697 people live in Monongalia County, West Virginia, spread over 360.094 square miles. Population density there runs about 302 people per square mile. Rank 181 by population within its EPA zone puts Monongalia County at the 83rd percentile among zone peers. Monongalia County falls in EPA Radon Region 3, one of 245 counties nationally EPA assigns to that same geologic province.

What this actually means for a house in Monongalia County

Outdoor air nationally averages about 0.4 pCi/L, indoor air about 1.3 pCi/L — Monongalia County's Zone 1 prediction clears both of those and EPA's fix-it threshold besides. That doesn't mean every Monongalia 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 Monongalia County

Nothing about Monongalia 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 West Virginia's state radon program

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

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