Ramsey County, ND: EPA's radon zone, explained

Ramsey County is mapped as Zone 1 - Highest Potential by EPA — meaning the county-wide average indoor level is predicted above 4 pCi/L. Nationally that's the 77th percentile for radon potential — Ramsey County outranks 77% of every county EPA has rated.

Where Ramsey County sits nationally

Ramsey County, North Dakota is home to about 11,510 people across 1,185.367 square miles. Averaged across its land area, Ramsey County runs about 10 people per square mile. By population, Ramsey County is the 733rd largest of every county sharing its EPA zone — the 31st percentile by population within that zone. Ramsey County falls in EPA Radon Region 8, one of 291 counties nationally EPA assigns to that same geologic province.

Why the zone isn't the answer by itself

Ramsey County carries a Zone 1 label because its predicted average clears 4 pCi/L outright — three-plus times the 0.4 pCi/L typical outdoors and above the 1.3 pCi/L most homes see. EPA's guidance doesn't change because of a Zone 1 label: test the house. What changes is the reason to not put it off in Ramsey County specifically.

If Ramsey County tests above the action level

For a Ramsey County homeowner, the order is simple: test first, since a kit costs a small fraction of what mitigation would. Only if the result clears 4 pCi/L does a system — typically $800–$2,500, about $1,200 for a common install — become worth pricing out.

Find North Dakota's state radon program

For Ramsey County, an ongoing number beats a one-time test - a Airthings radon monitor tracks Ramsey County's levels over time. RadonZoneCheck earns a commission there, at no extra cost to you. RADONZONE-10OFF at checkout knocks 10% off.

Where Ramsey County's figures come from

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