High radon in Sioux Falls is a fixable problem

Testing, mitigation, and help with a high result

Radon mitigation in Sioux Falls, SD is straightforward work. A gas rises out of the ground, collects in the house, and a system pulls it back out. You can’t see or smell radon, and public-health agencies tie long-term exposure to lung cancer. That sounds alarming. The useful news is that it’s one of the most fixable problems a house can have.

The path is well-worn. A test tells you the level. If the number is high, a mitigation system draws the gas from under the house and vents it above the roof, and a second test confirms the level came down. What mitigation involves is covered in plain terms on its own page, and so is radon testing.

Systems are designed to bring a home below the EPA action level of 4 picocuries per liter. Nobody honest promises a specific number before the work is done. The retest after installation is the proof, and it’s part of the job, not an extra.

Most people get here one of three ways. A home inspection turned up a number. A hardware-store kit came back high. Or a neighbor put in a system and got them wondering about their own basement. All three are normal, and none of them means something is wrong with the house itself. Radon comes from the ground under the home, not from anything anyone did. If you’re holding a result right now, start with what a high test means.

How radon mitigation works in a Sioux Falls house

The work runs in three moves: design, install, verify.

Design starts with the house itself. A full basement, a crawlspace, a sump pit, an addition on its own slab. Each one changes where a system can pull from, so the assessment reads the foundation before anything gets proposed.

The system itself is simple to picture. A suction point goes through the slab, or under a sealed liner if the home sits over a crawlspace. A pipe carries the soil gas up and releases it above the roofline. A fan keeps the air moving around the clock, and a small gauge on the pipe shows the suction is holding. Once the design is set, most residential installs are quick jobs, though the house has the final say.

Verification is the part worth being picky about. A system should bring the house below the action level, and the post-installation test is what shows it actually happened. Not a claim on a website. A number from your own basement. The gauge then tells you, at a glance, that the system is still pulling years later.

The full guide to how radon mitigation works walks through each piece with pictures. And if you’re still deciding whether your number calls for a system at all, what radon levels mean puts the scale in plain English.

Why basements around here test high

The upper Midwest tests high for radon more often than most of the country, and southeast South Dakota sits squarely in that pattern. The reason is under our feet. Glaciers ground across this region and left deep beds of till, the crushed rock and soil they carried. Those deposits hold traces of uranium. Uranium breaks down over time, and radon is one step in that breakdown. The gas moves easily through loose glacial soil and rises into whatever sits on top of it.

Around Sioux Falls, what sits on top is usually a house with a basement. Deep frost lines and storm season made basements the default here for generations. Postwar ranches near the center of town, the split-levels that filled out neighborhoods through the 1970s and 80s, and the newer walkouts on the edges of the metro all put livable space below grade. A finished basement bedroom or family room sits right where radon concentrates.

The long heating season adds to it. When the furnace runs and the windows stay shut, warm air rising through the house creates a gentle vacuum at the bottom. That vacuum pulls soil gas in through slab cracks, sump pits, and utility openings. It’s part of why a January test often reads higher than a July one.

None of this predicts your house. Two homes on the same block can test far apart, and the only way to know is to test. The state radon program publishes local data, and the highlights are gathered at radon levels in your area. If the test is happening because a house is changing hands, the clock matters more than the geology. Radon in a home sale covers how testing and mitigation fit inside a closing timeline.