City, Ogle County, Illinois
Radon Testing in Byron, IL
Updated
IEMA has 507 radon test results on record for Byron. 50.3% came back at or above the EPA's action level of 4.0 pCi/L. That is close to the Ogle County rate of 49.7%. A standard test runs $150 to $300. The only way to know about one specific house is to test it.
About 3,743 people live in Byron, a Ogle County city with roughly 1,545 housing units and a median year built of 1987. It sits near Oregon, Rochelle and Rockford. It sits on the Rock River and is home to the Byron Generating Station.
What IEMA's radon test records show
Look past the median to the tail: 5.3% of Byron tests were 20 pCi/L or more, five times the action level. The top reading on record is 72 pCi/L. The average result in Byron is 6.28 pCi/L, against 5.98 for Ogle County overall. IEMA's own dataset covers tests licensed measurement professionals submitted from 2003 through July 2019, keeping only the highest reading on record per address. That means it is not a random sample and not year-by-year, but it is the closest thing to primary local radon data that Illinois publishes.
| Tests | Avg pCi/L | 4+ pCi/L | 10+ | 20+ | |
|---|---|---|---|---|---|
| Byron | 507 | 6.28 | 50.3% | 16.6% | 5.3% |
| Ogle County | 1,751 | 5.98 | 49.7% | 15.7% | 3.9% |
Source: IEMA radon test records, Illinois Emergency Management Agency.
The ground under Byron
Ogle County straddles the Rock River south of Winnebago and Boone Counties, on dolomite and limestone bedrock with Ordovician rock visible in places along the riverbanks. The EPA rates the whole county Zone 1, its highest-potential radon classification, same as the counties to its north.
Housing in Byron
Census Bureau, American Community Survey 2020 to 2024 5-year estimates.
| Homes (housing units) | 1,545 | 22,682 in Ogle County |
| Median year built | 1987 | 1972 countywide |
| Built before 1980 | 53.3% | 71.8% countywide |
| Attached (rowhome, townhouse) | 4.4% | 2.2% countywide |
| Mobile homes | 0% | 2.5% countywide |
| Renter-occupied | 29.4% | 24.6% countywide |
Byron's housing stock has a median year built of 1987, against 1972 for Ogle County as a whole. Neither an old nor a new house here is safer by default, since the gas comes from the soil, not the construction. With 29.4% of Byron's housing renter-occupied, landlord testing questions come up often. There is no Illinois requirement to test a rental, but plenty of owners do it between tenants when the unit sits empty anyway.
What we do in Byron
Radon testing, Buying or selling a home, and New construction.
Common questions
Is radon a problem in Byron?
Yes. Out of 507 IEMA-recorded tests taken in Byron, 50.3% came in at 4.0 pCi/L or higher, the EPA's action level. That fits Ogle County's overall Zone 1 rating, the agency's highest-potential class.
What is the highest radon reading on record near Byron?
72 pCi/L, out of 507 IEMA-recorded tests. That is an outlier, not typical, but it shows why testing rather than guessing matters: neighboring houses can differ by a wide margin.
Does a new home in Byron still need radon testing?
Yes, and it matters here: 25.8% of Byron's homes went up in 2000 or later. New construction sits on the same ground as an old house, so age alone doesn't tell you the number. Test after the house is closed up.
Need radon testing booked in Byron?
Tell us why you're testing and any deadline you're working against. You get a fixed price and a straight answer back.