Radon Mitigation Cost and Kansas Rules in Johnson County

Prices on this page are estimates compiled from the published sources listed below, not quotes. JoCo Basement Safety is a free referral service that connects Johnson County homeowners with independent local pros. We are not a contractor and do not perform the work.

Is radon a problem in Johnson County?

K-State Research and Extension, Johnson County, reports an average test result of 5.3 pCi/L in the county, above the EPA action level of 4.0 pCi/L. KDHE cites EPA estimates that at least 1 in 4 Kansas homes will test at or above 4.0 pCi/L.

When to fix

EPA and KDHE recommend reducing radon in homes that test at 4.0 pCi/L or higher. EPA also recommends considering a fix between 2 and 4 pCi/L. Testing is the only way to know your level.

Cost (estimates)

KDHE states the typical cost of a professionally installed radon reduction system in Kansas is approximately $1,000 to $1,200. A third party estimator, RadonVerdict, lists a Johnson County range of $950 to $1,715. Basement layout and foundation type move the price.

Kansas certification rules

Kansas law requires anyone performing radon testing or mitigation in the state to be certified by KDHE. Since October 27, 2023 Kansas has adopted ANSI/AARST standards for mitigation. The Kansas Radon Program recommends getting at least two bids and asking whether the system is guaranteed to bring levels below 4.0 pCi/L.

Testing options

Johnson County K-State Extension sells test kits at its Olathe office. Real estate tests in Kansas must be done by a state certified measurement professional.

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FAQ

Do Kansas home sales require radon mitigation?

No. KDHE says Kansas does not require reduction in a sale, but contracts must include language encouraging buyers to test.

How well do systems work?

KDHE states mitigation systems reduce radon below 4.0 pCi/L in 95 percent or more of homes.

Sources

Last checked October 22, 2026.