Village, Boone County, Illinois
Radon Testing in Capron, IL
Updated
Out of 35 IEMA-recorded radon tests taken in Capron, 68.6% came back at 4.0 pCi/L or higher, the EPA's action level. Capron runs clearly hotter than the rest of Boone County on this measure. Testing runs $150 to $300 in this area. No number here tells you what your own house will read; only a test does that.
Capron is a village in Boone County with about 1,311 residents and 406 homes, median year built 1988. Neighboring towns include Poplar Grove and Belvidere. It's the smallest of the Boone County towns covered here, near the Wisconsin line.
What IEMA's radon test records show
25.7% of tests in Capron came in at 10 pCi/L or higher, well above the action level, and 11.4% were 20 or higher. The highest reading IEMA has on record here is 23 pCi/L. The average result in Capron is 8.05 pCi/L, against 5.22 for Boone County overall. This comes from IEMA's own records: results licensed measurement professionals submitted between 2003 and July 2019, with only the highest reading kept per address. Not a random sample, and not broken out year by year, but it is the closest primary radon data Illinois makes public.
| Tests | Avg pCi/L | 4+ pCi/L | 10+ | 20+ | |
|---|---|---|---|---|---|
| Capron | 35 | 8.05 | 68.6% | 25.7% | 11.4% |
| Boone County | 1,628 | 5.22 | 49.8% | 12.4% | 2.1% |
Source: IEMA radon test records, Illinois Emergency Management Agency.
The ground under Capron
East of Winnebago County, Boone County shares the same underlying bedrock: Ordovician and Silurian dolomite and limestone, buried under glacial till left by the last Ice Age. That geology puts Boone County in the EPA's Radon Zone 1 too, the agency's highest-potential classification.
Housing in Capron
Census Bureau, American Community Survey 2020 to 2024 5-year estimates.
| Homes (housing units) | 406 | 20,291 in Boone County |
| Median year built | 1988 | 1986 countywide |
| Built before 1980 | 51.5% | 54.2% countywide |
| Attached (rowhome, townhouse) | 6.2% | 5.4% countywide |
| Mobile homes | 6.4% | 6% countywide |
| Renter-occupied | 21.8% | 18.2% countywide |
Median year built in Capron is 1988, close to the Boone County median of 1986. Housing age here does not point to a clear pattern either way, which is normal: radon risk in this part of Illinois comes from the ground, not the building. Mobile and manufactured homes make up 6.4% of the housing in Capron. Without a basement, testing still happens at the lowest livable level, and any mitigation work looks different than a basement job.
What we do in Capron
Radon testing, Buying or selling a home, and New construction.
Common questions
Is radon a problem in Capron?
Yes. IEMA has 35 radon test results on record for Capron, and 68.6% came back at or above the EPA's 4.0 pCi/L action level. Boone County as a whole sits in EPA Radon Zone 1, the highest-potential category.
What is the highest radon reading on record near Capron?
23 pCi/L is the top reading IEMA has logged for Capron, among 35 tests on file. One high neighbor does not predict your own number, which is exactly why testing beats assuming.
We're closing on a house in Capron soon. Is there time to test?
Usually yes. A short-term test takes a few days to about a week, which fits inside most inspection periods if it's scheduled early. See our <a href="/real-estate-radon-testing">real estate radon testing</a> page for how that timing works.
Nearby
Poplar Grove (58.1% of tests at 4+ pCi/L), Belvidere (47.9% of tests at 4+ pCi/L).
Need radon testing booked in Capron?
Tell us why you're testing and any deadline you're working against. You get a fixed price and a straight answer back.