Radon Levels in Tiffin, IA
Tiffin is in Johnson County. Radon data is tracked at the county level by the EPA and CDC.
EPA predicts average indoor levels above 4 pCi/L in this county · Source: EPA, CDC
Tipper's take on radon in Tiffin
Tiffin sits in Johnson County, which the EPA classifies as Zone 1, the highest risk category. That means the agency's geological and indoor measurement data predicts average indoor radon levels above 4 pCi/L across the county. CDC data from Johnson County puts the average measured radon level at 4.7 pCi/L.
Zone 1 doesn't mean every home in Tiffin is over the limit. Radon varies house to house depending on foundation type, soil composition, and how the home is sealed. The county-level signal is strong enough that Tipper considers testing essential here.
A basic test kit costs about $15, takes 48 hours, and settles the question. If your home is below 4 pCi/L, you're good. If it's above, a mitigation system typically costs $800–$2,000 in Iowa and brings levels down reliably.
Sources: EPA Radon Zone Map, CDC Environmental Public Health Tracking
Test Your Home in Tiffin
A short-term test kit costs about $15, includes the lab fee, and gives you a result in 48 hours. It's the only way to know your home's actual radon level.
Radon Professionals Near Tiffin
Full County Data
Radon data is tracked at the county level. For state comparisons, nearby counties, and detailed analysis, see the full county page.
Johnson County, IA: Full Radon Data →Radon FAQ: Tiffin, IA
What is the radon risk in Tiffin?
Tiffin is in Johnson County, which the EPA classifies as Zone 1 (High risk). The county average is 4.7 pCi/L. The EPA recommends testing every home regardless of zone. Radon levels vary house to house.
How do I test my home in Tiffin for radon?
Place a short-term radon test kit in the lowest livable level of your home for 48 hours under closed-house conditions. Kits cost about $15 and include the lab fee. Keep windows and exterior doors closed during the test (normal entry/exit is fine). Results come back in about a week.
What should I do if radon is high in my Tiffin home?
If your test result is at or above 4 pCi/L, the EPA recommends installing a mitigation system. A certified contractor can install one for $800–$2,000 in most cases. The system runs continuously and typically brings levels well below 2 pCi/L. Retest after installation to confirm.
Does Zone 1 mean every home in Tiffin has high radon?
No. Zone 1 means the county-level prediction is above 4 pCi/L on average, but individual homes vary widely. Foundation type, soil conditions, and ventilation all matter. Some Zone 1 homes test below 2 pCi/L. The zone tells you to take it seriously. Your test tells you what to do.