Iowa & Nebraska Radon Guide for Sioux City (2026)

Updated October 19, 2026. This guide is general information, not legal or engineering advice. Rules change, so confirm with the agency listed before you start work.

Quick reference

Topic	What to know	Source
Iowa risk	EPA considers all of Iowa high risk for radon in homes	Iowa HHS
Nebraska risk	More than half of Nebraska radon tests are above 4.0 pCi/L	Nebraska DHHS
Action level	4 pCi/L; don't decide on a single test; consider 2 to 4	Iowa HHS; EPA
Iowa mitigation	Iowa HHS credential required to mitigate for a fee (641 IAC 44, effective July 1, 2026)	ARC 0290D
Iowa testing	Certification required for paid testing in buildings you don't own (641 IAC 43, effective July 1, 2026)	ARC 0289D
Before and after tests	Required unless owner waives; post-test 1 to 30 days after install; tester independent of mitigator	ARC 0290D
Performance	System must get radon below 4 pCi/L where installed	ARC 0290D
Nebraska	License required for radon occupations; free online lookup	Nebraska DHHS
Kits and help	Iowa Radon Hotline 1-800-383-5992	Iowa HHS
Retesting	At least every two years with a system	EPA

How common is radon in Siouxland?

Iowa HHS says the EPA considers the entire state of Iowa at high risk for radon in homes. Across the river, Nebraska DHHS reports that more than half of radon tests in Nebraska are above the 4.0 pCi/L action level. Levels vary from house to house, so a neighbor's result doesn't tell you yours.

Why does it matter?

The EPA estimates radon causes about 21,000 lung cancer deaths a year in the U.S. It's the leading cause of lung cancer among non-smokers and the second leading cause overall.

How should I test?

Test the lowest floor you live on with the house closed up. Short-term tests take a few days; long-term tests run more than 90 days and better reflect your average. Iowa's Radon Hotline at 1-800-383-5992 sells low-cost kits and answers questions, and Iowa HHS has offered one free kit per household through partner programs while supplies last. Iowa HHS cautions against basing a mitigation decision on a single test.

When should I fix it?

Iowa HHS treats results at or above 4 pCi/L as elevated and recommends mitigation. The EPA suggests considering a fix between 2 and 4 pCi/L. Sub-slab depressurization, a pipe and fan pulling soil gas from under the slab and venting it above the roof, is the standard fix. Crawl spaces get a sealed membrane with suction underneath.

What changed in Iowa's radon rules in 2026?

Iowa HHS rescinded and replaced its radon testing rules (641 IAC chapter 43) and mitigation rules (chapter 44), both effective July 1, 2026. Under the new mitigation chapter:

No one may mitigate radon for a fee in Iowa without an Iowa HHS credential, including out-of-state businesses serving Iowa residents. People mitigating a building they occupy are exempt.
Converting a passive system to active, or modifying an active system, requires a credentialed person.
Mitigation specialists must complete approved NRPP or NRSB measurement and mitigation courses and pass the national mitigation exam, and keep up continuing education.
Buildings are tested before and after mitigation unless the owner waives it on a department form. The post-mitigation test starts at least one day after the work is done and within 30 days of installation.
Pre- and post-mitigation tests are done by a measurement specialist from a different firm than the mitigator, or by the owner or occupant.
The system must reduce radon below 4 pCi/L in the area or level where it's installed.

Under the new testing chapter, anyone measuring radon for compensation in a building they don't own must be certified; owners testing their own buildings are exempt. Certified testers generally can't release results for nonpublic buildings without the owner's written waiver, with an exception for a prospective buyer who made an offer and paid for a test done within the past five years.

What about Nebraska?

Nebraska DHHS says anyone working on a radon project or in a radon occupation in Nebraska must have a license. It licenses measurement and mitigation specialists, and mitigation specialists need approved training, an approved exam, and two years of relevant education or experience. Licenses can be checked for free on Nebraska's online license lookup.

How do I keep a system working?

The EPA advises checking the system's warning device regularly and retesting at least every two years. Retest after major renovations, too.

Common questions

Do radon mitigators need a credential in Iowa?

Yes. Under Iowa's mitigation rules effective July 1, 2026, mitigating radon for a fee requires an Iowa HHS credential.

Is Sioux City a high-radon area?

Iowa HHS says the EPA considers the entire state of Iowa high risk. Test every home.

Where can I get a radon test kit in Sioux City?

Call Iowa's Radon Hotline at 1-800-383-5992, or buy a kit at a hardware store.

Siouxland radon guide: Iowa and Nebraska rules (2026)