The only way to know if your home has harmful levels of radon is to test.

Get a free test kit today!

January is an ideal month to test your home for radon. Test kits are available at no cost to you! 

Pick up a test kit in person

The Larimer County Department of Health and Environment is distributing radon test kits during January. Quantities are limited.

Order a test kit from CDPHE

The Colorado Department of Public Health and Environment is offering radon test kits. Quantities are limited. 

50% of Larimer County Homes Have Harmful Levels of Radon


    • The Colorado Department of Health and Environment has a Low Income Radon Mitigation Assistance program. Learn more. 
    • Some Health Savings Accounts (HSA) or Flexible Spending Accounts (FSA may pay for a radon mitigation system). Check with your plan to see if you qualify.  
  1. Radon is a naturally occurring radioactive gas.  You cannot see, smell, or taste radon.

    Radon is the leading cause of lung cancer in non-smokers. It can seep into your home through the ground.  About 50% of homes in Colorado have elevated levels of radon.

    The U.S. Environmental Protection Agency recommends radon be mitigated if the level is  4 picocuries per liter (pCi/L) or more. The only way to to know if your home has harmful levels of radon is to test for it.  If your home tests above the EPA action level, you are at an elevated risk of developing lung cancer from radon.

  2. Testing is easy and may be available for free! A monitor is placed in your home to sample the air. The monitor needs to sample the air for a specific period of time, sometimes several weeks. 

    If you're using a DIY test kit, the kit will come with specific instructions. Some contractors will test your home for radon for you. If you're using a contractor, they will give you specific instructions. 

    Radon Test Kit
  3. Mitigations means you take steps to reduce the level of radon in your home. Frequently, this means installing a sub-slab or sub-membrane depressurization system.  The Colorado Department of Health and Environment estimates for most homes, this will cost about $1,000 - $2,000. 

    Some homes already have a "passive radon" system. This means when the home was built, additional materials and structures were added. This can make it even easier and cheaper to mitigate your home for radon. 

    An attic of a home with a radon mitigation system installed

    When should I mitigate for radon?

    If your home tests at 4 picocuries per liter (pCi/L) or more, the EPA recommends you mitigate your home for radon. Because there is no known safe level of exposure to radon, EPA also recommends that Americans consider fixing their home for radon levels between 2 pCi/L and 4 pCi/L.

    Can I mitigate for radon myself?

    Some people choose to complete their own radon mitigation. CDPHE has resources available for people who may want to DIY their radon mitigation

    Where can I find a contractor?

    Many people choose to hire a contractor to mitigate their home for radon. The Colorado Department of Regulatory Agencies (DORA) certifies radon mitigation professionals. Check to see if your selected contractor is licensed by DORA.

    Larimer County Extension does not endorse or recommend any specific radon mitigation professionals. These lists of certified contractors are provided for informational purposes only.


  4. Your home’s radon level can be very different from your neighbor’s. The soil under your homes may be similar, but your home’s structure and foundation are unique.

    For example, if your home has a crawl space and your neighbor’s house does not have a crawl space, this can impact the radon reading. Additionally, the cracks and holes in you home's foundation will be different from your neighbor's home.  

    The only way to know if your home has a radon problem is to test for it.


  5. As of August 7, 2023, Colorado landlords must disclose radon information when a tenant signs a lease agreement. From CDPHE, "Tenants can void their lease if the landlord does not include the radon disclosure or if a landlord does not make reasonable efforts to mitigate elevated radon levels after 180 days."
    View bill text

    A Radon Guide for Tenants - from the Environmental Law Institute (ELI) and the U.S. Environmental Protection Agency

  6. There are some actions you can take to temporarily reduce radon levels in your home. Please note, none of these are replacements for a radon mitigation system. 

    • Open windows and use fans to circulate air
    • Seal cracks in floors and walls
    • Use a high-density plastic sheet to cover dirt crawlspace floors. Use a vent pipe and a fan to blow the radon from under the sheet and vent it outside.
    • Move sleeping areas from basements to higher levels of the home
    • Eliminate smoke and second hand smoke.  Call 1-800-QUIT-NOW or visit for free support and resources.
  7. Larimer County Department of Health and Environment (LCPHE) has a map of radon testing results in Larimer County

    Colorado Department of Public Health and Environment

    Environmental Protection Agency

    Summit County Environmental Health made a short video showing what some test kits took like (please note - your test kit may look slightly different):

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Colorado State University Extension is an equal opportunity provider. Colorado State University does not discriminate on the basis of disability and is committed to providing reasonable accommodations. CSU’s Office of Engagement and Extension ensures meaningful access and equal opportunities to participate to individuals whose first language is not English. Colorado State University Extension es un proveedor que ofrece igualdad de oportunidades.

Colorado State University no discrimina por motivos de discapacidad y se compromete a proporcionar adaptaciones razonables. Office of Engagement and Extension de CSU garantiza acceso significativo e igualdad de oportunidades para participar a las personas quienes su primer idioma no es el inglés.

Larimer County Colorado State University Extension

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1525 Blue Spruce Dr.
Fort Collins, CO 80524-2004

Phone: (970) 498-6000 

7:30 a.m. - 4:30 p.m.
Monday - Friday 

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Our office follows the Larimer County Holiday Calendar for office closures.