North Dakota has the second-highest average indoor radon level of any U.S. state, estimated at approximately 8.2 pCi/L statewide. The North Dakota Department of Environmental Quality estimates that approximately 65% of North Dakota homes have radon levels above 4.0 pCi/L. North Dakota’s geology — including glacial lake sediments, shale, and uranium-bearing lignite formations — creates extremely high radon potential across the entire state.
EPA Radon Zone Designation
North Dakota is predominantly EPA Radon Zone 1. All North Dakota counties are Zone 1 — the highest radon potential designation. The uniform Zone 1 designation reflects the consistent geology of glacial deposits and shale formations across the entire state. No county in North Dakota has a Zone 2 or Zone 3 designation.
Radon Contractor Licensing in North Dakota
North Dakota requires radon contractors to hold current NRPP or NRSB national certification to perform radon services in the state. The North Dakota Department of Environmental Quality administers radon program resources and maintains information on certified professionals. North Dakota does not have a separate state radon contractor licensing statute independent of national certification. Verify contractor credentials at nrpp.info or nrsb.org before hiring any radon professional.
Radon Disclosure Requirements in North Dakota
North Dakota’s real estate disclosure law requires sellers to disclose known material defects. While North Dakota does not have a radon-specific disclosure statute, the general material defect disclosure duty covers known elevated radon conditions. Given that approximately 65% of North Dakota homes exceed the EPA action level, radon testing is standard practice in North Dakota real estate transactions. Buyers should include radon contingencies in all purchase offers.
Radon-Resistant New Construction (RRNC) in North Dakota
North Dakota does not have a statewide mandate requiring RRNC for all new construction. However, given the state’s extreme radon prevalence with all counties in Zone 1 and an average exceeding twice the EPA action level, EPA and NDDEQ strongly recommend RRNC for all new North Dakota residential construction. All new homes in North Dakota should include passive RRNC features per AARST-ANSI RRNC-2022 at minimum.
Highest-Radon Counties and Areas in North Dakota
All 53 North Dakota counties are Zone 1 with high radon potential. The highest average readings have historically been documented in western North Dakota counties overlying oil-bearing shale formations (Divide, Burke, Mountrail, McLean, Mercer, Oliver, Morton, Grant, Emmons counties) and in central North Dakota where glacial lake bed sediments from prehistoric Lake Agassiz are present (Cass, Ransom, Richland, Sargent counties in the east).
Testing Resources for North Dakota Residents
The North Dakota Department of Environmental Quality administers the state radon program and provides resources for homeowners including lists of certified contractors, low-cost or free test kit programs (availability varies by year and funding), and technical guidance on radon mitigation. Contact the state radon program directly for the most current contractor list, any available test kit distribution programs, and jurisdiction-specific requirements that may have changed since this page was last updated.
Frequently Asked Questions
How high is radon in North Dakota?
North Dakota has the second-highest average indoor radon level in the U.S. — approximately 8.2 pCi/L statewide. About 65% of North Dakota homes exceed the EPA action level of 4.0 pCi/L. All 53 counties are designated EPA Zone 1.
Does North Dakota require radon contractor certification?
NRPP or NRSB national certification is required. There is no separate North Dakota-specific licensing statute. Verify credentials at nrpp.info or nrsb.org before hiring.
Should every North Dakota home be tested for radon?
Yes — emphatically. With 65% of homes above the EPA action level and all counties in Zone 1, every North Dakota home should be tested. The question in North Dakota is not whether radon is likely to be present, but how high the level is.
Leave a Reply