Sources
Official sources for the Denver radon test kit guide
Every factual claim on this site is meant to trace to EPA, CDPHE, or DORA. County zones come from EPA’s June 2024 radon-zone data behind the Map of Radon Zones. Colorado testing steps, the free-kit offer, placement rules, and the $10 to $50, about $150, and about $1,000 to $2,000 figures come from CDPHE’s testing page, FAQ, and understanding radon pages. The low-income mitigation program is named in CDPHE’s January 5, 2026 release.
This guide does not republish neighborhood averages, name mitigation companies, or invent license numbers. If a sentence does not match the page it links, the official page wins.
Colorado
- CDPHE testing and mitigation: Free kits, placement rules, real estate tests, and how sealing differs from a system.
- CDPHE understanding radon: Why about half of Colorado homes test over 4 pCi/L, and why the zone map is not a test.
- Colorado radon portal: CDPHE’s public radon site, including the path into low-income mitigation assistance.
- January 5, 2026 CDPHE release: Free kits and the Low-Income Radon Mitigation Assistance program, as the department described them.
- DORA license lookup: Verify a Colorado radon measurement or mitigation license. Do not hire from a postcard alone.
Find a certified professional
- NRPP professional search: National Radon Proficiency Program directory. In Colorado, also confirm the DORA license.
- NRSB find a pro: National Radon Safety Board directory. Same rule: the state license still has to be current.
- EPA: how to find a qualified provider: EPA’s overview of state programs plus NRPP and NRSB. Not a list of Denver companies.
EPA
- EPA radon home: National starting point: test every home, fix at 4 pCi/L or higher.
- Map of Radon Zones: County potential map. Denver County and the metro counties listed above are Zone 1.
- A Citizen’s Guide to Radon (PDF): Short-term versus long-term testing, the 4.1 pCi/L example, and radon myths.
- Consumer’s Guide to Radon Reduction (PDF): Why sealing alone is not a fix, and how soil-suction systems work.
- Health risk of radon: EPA’s risk overview, including the combined risk for people who smoke.
- A Radon Guide for Tenants (PDF): National renter explainer to read next to Colorado’s SB23-206 disclosure rule.
- EPA radon publications: Index of current EPA radon guides, including buyer and seller material.