Radon Testing in Iowa City, IA

Why Testing Matters More Here Than Almost Anywhere

Radon is a radioactive gas produced by the natural decay of uranium in soil. The glacial deposits under most of Iowa are unusually rich in that source material, which is why our state tops the national charts. The gas moves up through the ground and into houses through sump pits, floor drains, cracks in slabs and foundation walls, and open crawl spaces.

The health stakes are real. Radon is the second-leading cause of lung cancer overall and the leading cause among people who have never smoked. The EPA attributes roughly 21,000 lung cancer deaths in the United States each year to radon exposure. Risk builds with concentration and time, so the sooner you know your level, the sooner you can do something about it.

This applies to every kind of house we see in Johnson County. Pre-war homes near downtown, the Northside, and Longfellow have older foundations with plenty of entry points, but brand-new construction in North Liberty and Tiffin tests high all the time too. Tight, energy-efficient new homes can actually hold radon in. Age, price, and construction quality do not predict radon. Only a test does.

How Professional Radon Testing Works

We test with continuous radon monitors, usually shortened to CRMs. A CRM is a calibrated electronic instrument that samples the air and records the radon concentration every hour for the duration of the test, rather than producing one blended number at the end. We place it in the lowest lived-in level of the home, away from drafts, exterior doors, and high humidity.

A valid short-term test runs a minimum of 48 hours under closed-house conditions. That means windows stay shut and exterior doors are used only for normal coming and going, starting at least 12 hours before the test begins. Normal life continues; you just skip airing the place out. Closed-house conditions make sure we measure what the house actually does rather than what the weather is doing.

When we pick the monitor up, you get a written report showing the overall average plus the hour-by-hour readings. Those hourly graphs matter. They show normal daily rise and fall, and they also make it obvious if someone opened windows or moved the device during a real estate test. That tamper resistance is a big part of why CRM results carry weight in transactions.

Professional Testing vs. DIY Kits

Let us be straight about this: home test kits work, and Johnson County Public Health sells them cheaply. If you are simply curious about your own house and nothing rides on the result, a DIY charcoal kit is a perfectly reasonable first step, and we will never talk you out of one.

Professional testing earns its fee when the result has consequences. Real estate transactions need a fast, defensible number from a disinterested third party, and a mailed-in kit that takes weeks and depends on the occupant following instructions does not fit that job. Iowa City rental permits require testing performed to recognized standards. And when two parties dispute a result, whether that is a buyer and seller or a landlord and tenant, a calibrated CRM with hourly data settles the question in a way a charcoal envelope cannot.

There is also plain reliability. DIY kits can be skewed by humidity, poor placement, delays in mailing, and open windows nobody mentions. A CRM is calibrated on a regular schedule, placed by someone who does this constantly, and records conditions across the whole test window. When the number matters, use the tool built for it.

Testing for Real Estate and Iowa City Rentals

If you are selling a home in Iowa, Iowa Code chapter 136B requires you to disclose known radon test results and any mitigation work in the transaction. Buyers increasingly ask for a radon test during the inspection window, and a professional 48-hour CRM test fits neatly inside that timeline. If you are buying, we strongly recommend making the test part of your inspection contingency so any needed mitigation gets negotiated before closing rather than paid for after.

Landlords in Iowa City have a specific obligation. The city's rental ordinance, effective July 1, 2021, made Iowa City the first city in Iowa to require radon testing for single-family and duplex rental properties as part of the rental permit cycle, with mitigation required when levels come back at 4.0 pCi/L or higher. We handle this routinely: we schedule around tenants, run the test to standard, and deliver documentation formatted for the permit file. If the property needs mitigation, we can quote that in the same visit.

Reading Your Results: What the Numbers Mean

Radon is measured in picocuries per liter, written pCi/L. The EPA action level is 4.0 pCi/L: at or above that number, fix the home. The EPA also recommends considering action between 2.0 and 4.0, because there is no level of radon exposure that is truly risk-free, and mitigation systems routinely bring homes under 2.0.

Given that 7 in 10 Iowa homes land at or above 4.0, a high result here is the expected outcome, not a crisis. It does not mean your home is defective or unsellable. It means the soil under Johnson County does what Zone 1 soil does, and your house needs a well-understood, one-day fix.

One caution on interpretation: radon fluctuates by season, weather, and how the house is used. Winter readings usually run higher than summer because the house is sealed up. A single borderline result, say 3.5 in July, is a reason to retest in heating season, not a reason to relax.

What to Do After a High Test

If your average comes back at 4.0 pCi/L or higher, the next step is mitigation, most commonly an active sub-slab depressurization system that pulls radon from beneath the foundation and vents it above the roofline. A typical install in our area runs $900 to $1,400 and takes about a day. We walk you through the options for your specific foundation and give you a firm quote before anything gets drilled.

For a borderline result between 2.0 and 4.0, you have choices. Some homeowners mitigate right away for the peace of mind, especially with kids or a finished basement someone sleeps in. Others retest in a different season first. Both are sensible, and we will tell you honestly which we would do in your house rather than pushing the more expensive answer.

Whatever you decide, do not simply file the report away. Radon risk is cumulative, and the fix is modest compared to what is at stake.

When to Retest, and What Testing Costs

Testing is not a once-in-a-lifetime event. Retest every two years as general practice, after any major renovation or foundation work, after changes to your HVAC system, and before finishing a basement into living space. If you had a mitigation system installed, a post-mitigation retest verifies it works, and periodic checks alongside the system's u-tube manometer confirm it keeps working.

Professional testing in our area typically runs $150 to $250, depending on the property and the turnaround required. That covers monitor placement, the minimum 48-hour CRM measurement, pickup, and a written report suitable for your records, a real estate file, or an Iowa City rental permit.

If you are anywhere in Johnson County and do not know your number, call us or send the form on this page. We will get a monitor in your home this week and an answer in your hands about 48 hours after that.