Radon mitigation means changing how air and soil gas move in a house so less radon gets in and stays. EPA says to fix your home if your radon level is 4 pCi/L or higher, and to consider fixing it between 2 and 4 pCi/L [1]. Iowa HHS adds that mitigation decisions shouldn't be based on a single test result [2].
When a fix makes sense
EPA's testing steps start with a short-term test. If it reads 4 pCi/L or higher, you follow up with a long-term test or a second short-term test. If the first result is more than twice the action level, take the second short-term test right away [3]. Then fix the home if the long-term result is 4 or more, or consider fixing it if the average of the two short-term results is 4 or more [3]. The radon testing page covers how to set up a fair test.
Radon abatement and radon removal methods
Iowa law uses the word abatement for this work [4]. Contractors pick the method by foundation type. In basement and slab homes, EPA describes four kinds of soil suction: subslab, drain tile, sump hole and block wall [5].
- Subslab suction. Pipe goes through the floor slab, and a fan draws gas from beneath. EPA says it's the most common method and usually the most reliable [5].
- Sump hole suction. The sump can be capped so it still drains water and also works as the suction point [5].
- Block wall suction. This pulls radon from hollow block walls and is often paired with subslab suction [5].
- Submembrane suction for crawl spaces. See crawl space radon.
Sealing cracks helps the other methods work, but EPA doesn't recommend sealing alone because it hasn't been shown to lower levels much or consistently [5]. For radon remediation in water from a private well, test the air first, as EPA advises [6].
What Iowa expects during the job
Under Iowa's mitigation rule, effective July 1, 2026, a credentialed specialist makes sure the home is tested before and after the work unless the owner signs a waiver on a state form first [7]. The follow-up test can't start sooner than one day after the work is finished and must start within 30 days of installation [7]. It must be done by the homeowner or by a measurement specialist who doesn't work for the mitigation firm [7]. The system has to bring radon below 4 pCi/L in the area or level of the building where it's installed [7]. The rest of the state rules are on how it works.
After it's installed
EPA says to check the warning device, usually a manometer, on a regular basis, to keep the fan running all the time, and to retest at least every two years [5]. If the fan fails, see radon fan replacement. For prices, see radon mitigation cost.
FAQ
Will a system get my level to zero?
Not to outdoor levels. EPA notes that outdoor air holds about 0.4 pCi/L and that matching it isn't yet technologically achievable, but most homes today can be brought down to 2 pCi/L or below [3].
Does the contractor do my post-test?
Under Iowa's rule, the test is done by you, the occupant, or a measurement specialist from a different firm [7].
Get a quote
Ask for a mitigation quote and mention your foundation type.
We're a referral service, not a contractor. We send mitigation requests only to contractors on Iowa HHS's current credentialed list and testing requests only to state-certified radon measurement specialists, but we don't otherwise vet them, a referral is not an endorsement, and independent contractors may pay us for referrals.
Sources
- U.S. EPA, EPA Map of Radon Zones, last updated Aug 17, 2026. https://www.epa.gov/radon/epa-map-radon-zones
- Iowa HHS, Radon program page (fetched Nov 11, 2026). https://hhs.iowa.gov/health-prevention/providers-professionals/radiological-health/radon
- U.S. EPA, A Citizen's Guide to Radon, EPA 402/K-12/002 (2025 edition, PDF). https://www.epa.gov/sites/default/files/2016-12/documents/2016_a_citizens_guide_to_radon.pdf
- Iowa Code chapter 136B, Radon Control (2026). https://www.legis.iowa.gov/docs/code/136B.pdf
- U.S. EPA, Consumer's Guide to Radon Reduction, EPA 402/K-10/005 (2025 edition, PDF). https://www.epa.gov/sites/default/files/2016-12/documents/2016_consumers_guide_to_radon_reduction.pdf
- U.S. EPA, Home Buyer's and Seller's Guide to Radon, EPA 402/K-24/001 (revised March 2024, PDF). https://www.epa.gov/sites/default/files/2015-05/documents/hmbuygud.pdf
- Iowa Administrative Code 641, Chapter 44, Radon Mitigation (ARC 0290D, IAB 5/13/26, effective 7/1/26). https://www.legis.iowa.gov/docs/iac/chapter/641.44.pdf