Name: Cheyenne Radon Mitigation
Telephone: (307) 317-5825

Here's what public agencies and researchers have published about radon in Cheyenne and Laramie County. Every number on this page links to its source.

EPA radon zone: Zone 1

The EPA Map of Radon Zones places Laramie County in Zone 1, the highest-potential category. Zone 1 means the predicted county-average indoor screening level is above 4 pCi/L. Neighboring Albany County, home to Laramie, is also Zone 1. The EPA built the map in 1993 from indoor measurements, geology, aerial radioactivity, soils, and foundation types. It's meant for planning programs and building codes, and the EPA says not to use it to decide whether an individual house should be tested. Every house should be.

Test results in Laramie County

The American Lung Association's 2022 radon testing report for Wyoming, built on CDC Environmental Public Health Tracking data, lists Laramie County with 1,834 tests and a mean of 3.8 pCi/L. That's an average of homes that chose to test, many during sales, not a random survey, but it sits close to the EPA's 4 pCi/L action level. It means many individual homes are above it.

The Wyoming Department of Health also publishes an interactive radon data map and county averages for home test results. Use it to compare your area with others.

What the state says

According to the Wyoming Department of Health's Cancer Program:

Any home can have a radon problem: new or old, well-sealed or drafty, with or without a basement.
Lung cancer is the leading cause of cancer-related deaths in Wyoming.
The EPA estimates radon causes about 21,000 lung cancer deaths a year nationally, and radon raises smokers' risk further.

WDH has run free radon test kit giveaways for residents while supplies last. Check its radon page for current availability.

The geology

The U.S. Geological Survey's geologic radon assessment for EPA Region 8, which includes Wyoming, links radon potential to uranium-bearing rock and the soils derived from it. Cheyenne lies on the High Plains just east of the Laramie Range, whose core is Precambrian granite. Granites commonly contain more uranium than many other rock types. Over millions of years, erosion carried granite-derived gravels, sands, and silts eastward to form the sediments that now underlie much of Laramie County. Soils and sediments with that origin can produce significant radon, and dry, permeable gravels can let soil gas move freely toward foundations.

That's the general picture. Conditions vary from lot to lot, which is why neighbors' test results can differ widely.

Questions about a reading? A certified Cheyenne-area pro can help. (307) 317-5825

Climate makes a difference

Cheyenne's long heating season matters as much as the rock. When the furnace runs for months, warm air escaping from the upper house pulls soil air in through the foundation, the stack effect. Combined with tightly sealed, energy-efficient construction, that can push winter radon levels higher than summer ones. A winter-inclusive long-term test is the best measure of year-round exposure.

Licensing in Wyoming

Wyoming has no state radon licensing program for testers or mitigators. Look for current certification through the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB).

What to do with this information

Test your lowest lived-in level. See radon testing in Cheyenne.
If you're on a private well, test the water as well. See well water radon.
If you're at or above 4 pCi/L, talk to a certified mitigator. See mitigation.

Radon in Cheyenne and Laramie County