Long-term kit
RL416 long-term radon test kit, lab fee included
- Lab fee included
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Scott County, Illinois
EPA puts Scott County in Zone 1, its highest radon zone, and only 9 radon tests from it are on file with CDC (2017). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Highest bordering
64.5%
Morgan County
- Morgan
- 64.5%
- Pike
- 46.3%
2 of 3 neighbours have 30+ tests, 2008 to 2017
Nearest county
64.5%
Morgan County, 15 miles
- Morgan
- 64.5%
- Illinois
- 43.1%
Share at 4+ pCi/L, 169 tests, 2008 to 2017
Ground above low
100.0%
0.9 pts above Illinois
- Scott
- 100.0%
- Illinois
- 99.1%
Share of land USGS rates moderate or high potential
Tests reported
17
Too few for a share
- Scott
- 17
- Needed
- 30
2007 to 2016, laboratory
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Read a result for Scott County
Starts at EPA's action level
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.0 pCi/L
At or above 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher.
The data
Scott County, At a glance
Scott County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Scott County in
USGS geologic potential: High across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Scott County, 2017
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 100.0% |
| 2015 | 0.0% |
| 2017 | 0.0% |
2017: 0.0%. Across these years the share ran from 0.0% to 100.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 9 tests were reported to CDC for Scott County over 2017, and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor this house.
Measured: CDC tracking data. Figure above: 2017. Measured data period: 2005 to 2017 (every CDC figure on file).
Scott County, Compared
Scott County radon figures, compared
Calculated by Radon411CDC's largest figure for Scott County rests on 17 tests over the 2007 to 2016 laboratory totals, 11 of them at or above 4 pCi/L, so each test moves its share by 5.9 points and no rank or comparison is drawn from it. Results reached as high as 15.5 pCi/L, with a middle value of 7.1 pCi/L.
Of the counties bordering it, 2 have a figure over the 2008 to 2017 laboratory totals: Morgan County reported the largest share at or above 4 pCi/L, 64.5%, and Pike County the smallest, 46.3%. Farther out, Cass County (26 miles away) at 38.5%, Brown County (26 miles away) at 37.8% and Schuyler County (36 miles away) at 43.9% have figures too. Pooled across 102 Illinois counties, 43.1% of reported tests reached that level; across every county in the country with a figure, 35.7%.
Statewide for the same period, Stark County reported the highest share (80.5%) and Williamson County the lowest (13.3%). EPA's 1993 map puts Scott County in Zone 1, the map's highest label: a predicted county average above 4 pCi/L. USGS geology rates 100% of the county's land high radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Scott County, Geology
The ground under Scott County
PredictedUSGS's geologic map puts all of Scott County's mapped land in one class: high radon potential. All of it lies in the area the map calls Galesburg Plain, to which USGS gives a radon index of 13, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Galesburg Plain | Illinoian glacial deposits and loess over Paleozoic sedimentary rocks. | High | 13 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Scott County beside the ground around it
Scott County has more high-potential ground than Illinois as a whole: 100% of its land against 64.5%. Of the 3 counties that border it, none has as large a share of high-potential ground; Greene County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Scott County, Local resources
Radon testing and mitigation in Scott County
- IEMA-OHS Radon ProgramIEMA-OHS Radon Program, run by Illinois Emergency Management Agency and Office of Homeland Security, licenses or certifies radon professionals and states the rule for disclosing radon when a home is sold, and answers questions about testing and mitigation in Illinois.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsAsk the program whether it has free or discounted kits, or compare kits you can buy.
- Compare kits
- Professionals in Illinois339 professionals are listed in Illinois.
What Illinois's program says
- Phone
- (800) 325-1245
- Licensing of radon professionals
The Agency also licenses and regulates the individuals who provide radon measurement and mitigation to the public.
- Disclosure when a home is sold or rented
Illinois Radon Awareness Act - This is the legislation that requires the seller to provide to the buyer of any interest in residential real property the IEMA-OHS pamphlet entitled "Radon Testing Guidelines for Real Estate Transactions" and the Illinois Disclosure of Information on Radon Hazards.
What it means
Scott County, Questions
Questions about radon in Scott County
Are radon levels high in Scott County?
In 2017, 0.0% of the radon tests reported to CDC for Scott County, Illinois were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.6 pCi/L. Of the counties bordering it, 2 have a figure over the 2008 to 2017 laboratory totals: Morgan County reported the largest share at or above 4 pCi/L, 64.5%, and Pike County the smallest, 46.3%.
Which counties border Scott County?
Scott County borders 3 counties: Morgan County, Greene County and Pike County.
Products
Scott County, Products
Testing a home in Scott County
No CDC figure names Scott County; the nearest county with one, Morgan County (15 miles away), reported 64.5% of its tests at or above 4 pCi/L over the 2008 to 2017 laboratory totals, the only reading nearby until a test of this home. In Zone 1 the year-round level in Scott County is the one to know: a long-term test (more than 90 days) or a monitor, with a short-term kit for a first answer.
Test kits and monitors3
See every kit and monitorMonitorSafetySiren
Pro4 plug-in radon detector with a display and alarm
- C-NRPP 2024/25: Not included
- Plug-in
- Alarm
- Screen
First reading: Within 48 hours
Short-term kit
Radon Short Term Test Kit short-term charcoal radon test kit, lab fee included
- Lab fee included
Method: Charcoal
In home: 2 to 7 days
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Scott County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Scott County
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Scott County, Bordering counties
Counties bordering Scott County
Calculated by Radon411- Radon levels in Morgan CountyEPA zone 1
64.5%at or above 4 pCi/L
Median 5.8 pCi/L · 169 tests
- Radon levels in Pike CountyEPA zone 1
46.3%at or above 4 pCi/L
Median 3.8 pCi/L · 108 tests
- Radon levels in Greene CountyEPA zone 1
42.9%at or above 4 pCi/L
Median 3.5 pCi/L · 21 tests
Scott County, Cities and towns
Cities and towns in Scott County
About 4,866 people live in Scott County by the Census Bureau's estimate for July 1, 2025, 204 fewer than in 2020 (−4.0%). That works out to 19 people per square mile of land. Its largest town, Winchester, has 1,502 residents, 30.9% of the total. Together its 7 incorporated places hold 58.1% of those residents; the other 41.9% live outside any of them. Reported testing is thin here: 17 tests over 2007 to 2016, or 3.5 for every 1,000 residents (2025 estimate), where Illinois as a whole comes to 8.3.
From Winchester to Exeter, CDC publishes no figure by town: each reads Scott County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Winchester | 1,502 | −4.3% | 30.9% |
| Bluffs | 592 | −4.4% | 12.2% |
| Manchester | 261 | −4.7% | 5.4% |
| Alsey | 185 | −3.6% | 3.8% |
| Glasgow | 108 | −3.6% | 2.2% |
| Naples | 94 | −4.1% | 1.9% |
| Exeter | 83 | −3.5% | 1.7% |
7 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).
Scott County, Homes
Homes in Scott County
Scott County is a place of houses on their own lots: 82% of its 2,393 homes are detached single-family houses, against 58% across Illinois. The homes are older than Illinois' as a whole: half were built before 1962 (1970 for Illinois), and 46% date from before 1960. Owners live in 79% of the occupied homes (Illinois: 67%), so for most households a test and a fix are their own to order.
| Homes | Scott County | Illinois |
|---|---|---|
| Housing units | 2,393 | 5,443,501 |
| Detached houses | 82% | 58% |
| In buildings of 5 or more | 1% | 22% |
| Mobile homes | 9% | 2% |
| Built before 1960 | 46% | 38% |
| Built since 2000 | 13% | 16% |
| Middle year built | 1962 | 1970 |
| Owner-occupied | 79% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.