Colorado (CO) - Radon Levels & Risk Assessment

Colorado is classified as EPA Zone 1 (Highest Potential) for radon potential, with an average indoor radon level of 6.3 pCi/L. This exceeds the EPA action level of 4.0 pCi/L, meaning most homes in the state should be tested and many will need mitigation. Approximately 50% of homes in Colorado have radon levels above 4.0 pCi/L.

Radon Data for Colorado

Radon Risk in Colorado

As an EPA Zone 1 (Highest Potential) state, Colorado has some of the highest radon potential in the country. The underlying geology, rich in uranium-bearing rock and soil, produces elevated levels of radon gas that can accumulate in buildings. The average indoor radon level of 6.3 pCi/L is above the EPA action level of 4.0 pCi/L, making testing and mitigation especially important for homeowners.

Testing and Mitigation in Colorado

While Colorado does not mandate radon testing, it is strongly recommended by both the EPA and state health agencies. Many home buyers include radon testing as part of their home inspection. The average cost of radon mitigation in Colorado is $1,300, which is near the national average. Professional radon testers and mitigators in Colorado can be found through the NRPP (National Radon Proficiency Program) or the NRSB (National Radon Safety Board) directories.

Protecting Your Home in Colorado

The EPA recommends that all homes in Colorado be tested for radon, regardless of the state's overall zone classification. If your home tests at 4.0 pCi/L or above, install a mitigation system. If your home tests between 2.0 and 4.0 pCi/L, the EPA suggests considering mitigation. New construction in Colorado may benefit from radon-resistant building techniques (RRNC), which are inexpensive to include during construction and can be easily activated later if radon levels are found to be elevated.

Use our radon risk assessment tool for a personalized estimate based on your home's characteristics, or browse all states to compare radon data across the country.