Radon in Genesee County: Levels, Testing and Mitigation Cost
What state test data shows from Fenton to Flint, how the 48-hour test works, and what a fix costs
Radon is elevated in about 1 in 4 Michigan homes, according to Michigan EGLE (Department of Environment, Great Lakes, and Energy), and Genesee County runs a little lower: on EGLE's county map, 20 percent of homes tested here came in at or above 4 picocuries per liter (pCi/L), the level at which the Environmental Protection Agency (EPA) recommends fixing a home. Inside the county the spread is wide, from Flint zip codes where few tests run high to Fenton, where 38 percent of first-time tests topped 4 pCi/L. A test is the only way to know where a particular house falls, and if it comes back high, EGLE puts a typical mitigation system at $800 to $2,000 or more.
Michigan Property Inspections tests for radon from $200 when added to a home inspection.
How common is radon in Genesee County?
EGLE's map of elevated radon results by county puts Genesee at 20 percent of tested homes at or above 4 pCi/L. Every county that touches it except Saginaw, at 15 percent, is higher: Livingston at 40 percent, Shiawassee at 30, and Oakland, Lapeer and Tuscola at 29 each. EGLE says elevated levels have been found in all 83 Michigan counties.
EGLE's zip code map gets closer to home. It reports first-time tests in homes without a mitigation system, built from short-term kits bought through the state radon program over the past 10 years. In the map's May 2026 data, the share of tests above 4 pCi/L was:
- Fenton (48430): 38 percent of 233 tests, with a high of 29 pCi/L
- Linden (48451): 33 percent of 80 tests
- Goodrich (48438): 27 percent of 48 tests, with a high of 29.6 pCi/L
- Davison (48423): 22 percent of 60 tests
- Swartz Creek (48473): 18 percent of 40 tests
- Flushing (48433): 13 percent of 48 tests
- Grand Blanc (48439): 12 percent of 100 tests
Every Flint zip code on the map came in at 15 percent or lower. But even in Grand Blanc, 42 percent of first-time tests were above 2 pCi/L, the level at which the EPA says to consider fixing. These are kits people chose to buy, not a random survey, and EGLE's note on its county map says the map is not meant to decide whether a home should be tested. All homes should be.
How dangerous is radon?
Radon is a radioactive gas that comes from the natural breakdown of uranium in soil, and it gets into houses through cracks and other openings in the foundation. You cannot see, smell or taste it. The EPA estimates radon causes about 21,000 lung cancer deaths in the U.S. every year, making it the second leading cause of lung cancer overall and the leading cause among non-smokers.
For scale, the EPA puts the average indoor level in American homes at about 1.3 pCi/L and outdoor air at 0.4 pCi/L. The median first-time test in Fenton was 2.7 pCi/L, about twice the national indoor average. In Grand Blanc it was 1.6.
How does a 48-hour radon test work?
The EPA's Citizen's Guide to Radon describes short-term tests that stay in a home from two to 90 days, depending on the device. Ours runs 48 hours: we place the test equipment in the basement, collect it at the end of the test and take it to a certified lab. Radon results come back in 2 to 5 business days, and the home inspection itself comes with a same-day digital report.
For a two- or three-day test, the EPA's guide says to close windows and outside doors at least 12 hours before it starts, keep them closed as much as possible while it runs, and not run fans or other machines that bring in air from outside. If you are selling, that is the one thing to plan around.
For a house you already own, the EPA's guide says to take a follow-up test when a short-term result is 4 pCi/L or higher.
What should you do if radon is above 4 pCi/L?
The EPA recommends fixing a home at 4 pCi/L or higher and says to consider fixing between 2 and 4. EGLE's advice to buyers is not to despair: reliable reduction techniques exist, and the fix can happen before or after closing. Waiting until after closing allows a long-term test to confirm the level, and the money can be held in escrow for the system.
EGLE recommends hiring a mitigation contractor certified by the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB). Sealing floor cracks alone will generally not take care of the problem, EGLE says. Once the system is running, the EPA says to retest no sooner than 24 hours and within 30 days, then at least every two years. EGLE says a quality system may bring year-round levels below 2 pCi/L.
We test; we never repair or remediate, so nothing in the report is a sales pitch.
How much does radon mitigation cost in Michigan?
EGLE puts typical installation costs for a radon mitigation system at $800 to $2,000 or more. The EPA calls sub-slab suction the most common and usually the most reliable method: one or more pipes go through the floor slab into the crushed rock or soil underneath, and a fan draws the radon out and vents it to the air above the home. Some systems cut radon by up to 99 percent, according to the EPA, and the price depends on the size and design of the home and the methods it needs, so get more than one estimate.
Running costs are small. EGLE says the fan typically lasts about 11 years, averages about $3 a month to operate, needs no periodic maintenance and costs $145 to $300 to replace.
