Do I need a radon test in Jefferson County?
Yes. If you own a home in Jefferson County, or you are buying one, you should test for radon. Colorado is one of the highest-radon states in the country, and Jeffco sits right in the middle of it.
Why Jefferson County
Radon is a naturally occurring radioactive gas that comes from uranium breaking down in soil. You cannot see it, smell it, or taste it, and Colorado's geology produces a lot of it. It moves up through the ground and collects in the lowest levels of a home.
State health department data shows about half of Colorado homes test above the EPA action level. Jefferson County's own test results, collected by the state since 2005, track that: about half of tested homes came back at or above 4.0 pCi/L, with a county median right at 4.0.
Radon is the second leading cause of lung cancer in the US, and the leading cause among people who never smoked. It is responsible for about 21,000 deaths a year nationally.
One thing I tell every buyer: your neighbor's test tells you nothing about your house. Levels vary from house to house on the same street, and brand new homes test high too. The only way to know your number is to test.
What the number means
The EPA action level is 4.0 picocuries per liter (pCi/L). At or above 4.0, the EPA recommends fixing the home. Between 2.0 and 4.0, the EPA suggests considering it. There is no known safe level, but 4.0 is the line where action is recommended.
How a test works
A continuous radon monitor sits in the lowest lived-in level of the home for at least 48 hours, with the house closed up: windows and exterior doors shut except for normal coming and going. You get a written result the day the monitor is picked up. During a home purchase, the monitor usually goes in during the inspection and gets picked up about two days later.
If the level is high
The fix is a mitigation system: a fan and vent pipe that pull radon from beneath the foundation and exhaust it above the roofline. In Colorado these usually run about $1,000 to $2,000, install in a day, and can cut radon levels by up to 99 percent. In a purchase, sellers commonly pay for the system or credit the cost. High radon is very fixable, and it rarely kills a deal.
If you are in the Denver metro
I am Bard Nielsen, owner of Golden Peak Inspection in Golden, CO. I run 48-hour radon tests across Jefferson County and the Denver metro, usually alongside the home inspection, and I am NRSB certified for radon measurement. Call or text 303-803-5412.