Radon testing in the Illinois Quad Cities
Testing in Moline, Rock Island, East Moline, and the towns behind them is standard practice, with one placement question that comes up constantly: in a walkout or split-level, which floor counts as the lowest lived-in level.
Rock Island and Henry counties sit above Pennsylvanian and Mississippian bedrock with comparatively thin glacial cover, and the Mississippi bluffs expose the sequence outright. Loess caps the uplands above the river, and the terraces below are sand and gravel. Both move soil gas, and the region’s coal-measure geology adds shales that are locally uranium-bearing.
How testing works in this market
The answer is the lowest level with living space, even if part of that level is at grade. In a bluff walkout with a finished lower family room, that room is the measurement location. In a split-level with a tuck-under garage and a lower den, the den is. Keep the house closed twelve hours before and throughout a short-term test, keep the detector twenty inches off the floor and away from the walkout door itself, and record the exact position — the confirming test and the post-mitigation test belong in the same place. Moline, Rock Island, and East Moline carry a dense stock of 1890s–1940s workers’ housing on limestone and block foundations, much of it on the bluff slopes, with postwar ranches filling in behind. Silvis, Milan, and Coal Valley added ranch and split-level subdivisions from the 1960s onward. Geneseo and Colona keep small-town and rural housing with older cellars and later additions.
When to test, and when to retest
A first result is a starting point, not a verdict. EPA's guidance is to confirm a short-term result before spending money on a system, to test the lowest lived-in level, and to keep the house under closed-building conditions throughout. A measurement done for pay in Illinois calls for an IEMA-OHS measurement license; a do-it-yourself kit you buy and mail in yourself does not, and for a first look at your own house it is a legitimate place to start. River-valley winters give reliable closed-house conditions from December through March. Spring high water does not directly change radon, but saturated ground can temporarily alter how soil gas moves, which is one more argument for confirming a borderline reading rather than acting on a single short-term test taken during a wet week.
Testing inside a home sale
For an Illinois-side home, the Illinois Radon Awareness Act governs the sale: sellers provide the state radon pamphlet and disclose known elevated results, with no testing or mitigation mandate. Buyers moving across the river should not assume the paperwork or the timeline matches what they saw in Iowa — the two states handle radon disclosure differently.
Communities we route in Quad Cities (Illinois)
Radon Testing questions in Quad Cities (Illinois)
We are buying across the river. Does an Iowa test transfer to an Illinois house?
A test measures a specific building, so it never transfers between properties in any direction. What differs between the states is the legal frame around disclosure and who may measure for compensation — Illinois requires an IEMA-OHS measurement license, Iowa has its own certification. If your deal is on the Illinois side, the Illinois rules apply regardless of where your agent or inspector is based.
What do homeowners in the Illinois Quad Cities get wrong about testing?
Homeowners on the bluffs ask whether a walkout basement is somehow lower risk because one wall is open — it is not, since the buried faces and the slab are still soil-contact. Owners of older Rock Island and Moline housing ask about limestone foundations. Buyers ask why an Illinois-side quote differs from an Iowa-side quote for a similar house across the river.
Can I use a hardware-store kit instead of hiring someone?
For your own information, yes — a do-it-yourself short-term kit placed on the lowest lived-in level of a home in the Illinois Quad Cities, under closed-building conditions, is a real measurement, and EPA treats it as a legitimate first step. For a real-estate transaction the parties usually want an independent measurement by someone holding an IEMA-OHS measurement license, because a self-reported number from an interested party is easy for the other side to challenge.
Related Quad Cities (Illinois) guides
- Radon mitigation in Quad Cities (Illinois)
- Mitigation cost in Quad Cities (Illinois)
- Failed a radon test in Quad Cities (Illinois)
- System installation in Quad Cities (Illinois)
- Illinois radon contractors: join our network
Decision guides for this stage
- How radon testing works
- Continuous monitors vs short-term kits
- What the EPA actually recommends
- All homeowner decision guides
If a test in the Illinois side of the Quad Cities comes back high, the next pages worth reading are the elevated-result guide and the cost breakdown for this market. Coverage here spans Rock Island and Henry; the quote form resolves your ZIP against that list before you type anything else.
Sources
- U.S. EPA — Radon
- U.S. EPA — A Citizen’s Guide to Radon
- U.S. EPA — Consumer’s Guide to Radon Reduction
- U.S. EPA — EPA Map of Radon Zones
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