Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
Locations and reports
Radon Levels in Decatur County, Kansas
EPA puts Decatur County in Zone 1, its highest radon zone, and only 3 radon tests from it are on file with CDC (2022). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
86.7%
54.9 pts above KS
- Decatur
- 86.7%
- Kansas
- 31.8%
45 tests, 2021
Median result
6.8pCi/L
Action level reached
- Decatur
- 6.8 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2021
Tests reported
45
50th of 62 by tests
- Decatur
- 45
- Johnson
- 25,860
Reported to CDC before any fix, 2021
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Kansas
2 of 62
Top quarter
- Decatur
- 86.7%
- Norton
- 93.8%
By share, of 62 with 30+ tests
Read a result for Decatur County
Starts at Decatur County's median, 6.8 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 6.8 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. Decatur County's median reported result, 2021.
The data
Decatur County, At a glance
Decatur County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Decatur 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 Decatur County, 2022
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2016 | 33.3% |
| 2017 | 58.3% |
| 2018 | 50.0% |
| 2019 | 66.7% |
| 2020 | 58.3% |
| 2021 | 86.7% |
| 2022 | 100.0% |
2022: 100.0%. Across these years the share ran from 33.3% to 100.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 3 tests were reported to CDC for Decatur County over 2022, 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: 2022. Measured data period: 2016 to 2022 (every CDC figure on file).
Decatur County, Compared
Decatur County radon figures, compared
Calculated by Radon411More than half: 86.7% of the 45 radon tests reported to CDC for Decatur County in 2021 read at least 4 pCi/L. That places it 2nd of 62 Kansas counties with 30 or more tests for the same period. That is 54.9 points above the 31.8% pooled from 96 Kansas counties.
The newest figure, in 2022, counts only 3 tests (100.0% at or above 4 pCi/L), too few to compare, so this reading uses the 45-test figure.
The median result, 6.8 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 14.7 pCi/L. The rest split 6.7% under 2 pCi/L and 6.7% from 2 to 4 (Kansas: 45.3% and 22.9%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 86.7% share point the same way here.
1 of its 3 bordering counties with figures ran higher, led by Norton County at 93.8%; Red Willow County, NE reported 48.0%. Statewide for the same period, Norton County reported the highest share (93.8%) and Doniphan County the lowest (0.0%).
The busiest year on file was 2021, with 45 tests reported; the quietest, 2018, had 2.
Nationally, every county with a figure for the same period pools to 24.4%; Decatur County sits 62.3 points above it. CDC also counts 6 tests taken after mitigation in Decatur County for the same period: tests in homes where a fix was already in.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Decatur County, Geology
The ground under Decatur County
PredictedUSGS's geologic map puts all of Decatur County's mapped land in one class: high radon potential. All of it lies in the area the map calls Ogallala Formation, to which USGS gives a radon index of 12, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Ogallala Formation | Tertiary sandstone, in part covered by windblown eolian sand and loess deposits. | High | 12 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Decatur County beside the ground around it
Decatur County has more high-potential ground than Kansas as a whole: 100% of its land against 59.9%. Of the 6 counties that border it, none has as large a share of high-potential ground; Rawlins County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Decatur County, Local resources
Radon testing and mitigation in Decatur County
- Kansas Radon ProgramKansas Radon Program answers questions about testing, mitigation and the rules in Kansas.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 Kansas178 professionals are listed in Kansas.
What Kansas's program says
- Phone
- (800) 693-5343
What it means
Decatur County, Questions
Questions about radon in Decatur County
Are radon levels high in Decatur County?
In 2022, 100.0% of the radon tests reported to CDC for Decatur County, Kansas were at or above 4 pCi/L, and the median reported pre-mitigation result was 8.4 pCi/L. Of 62 Kansas counties with 30 or more tests for the same period, 1 reported a higher share; pooled, the state comes to 31.8%.
Which counties border Decatur County?
Decatur County borders 6 counties: Norton County, KS, Sheridan County, KS, Rawlins County, KS, Red Willow County, NE, Furnas County, NE and Thomas County, KS.
Products
Decatur County, Products
Testing a home in Decatur County
In Decatur County, 86.7% of 45 tests reported to CDC in 2021 reached 4 pCi/L, against 31.8% pooled across Kansas. In Zone 1 the year-round level in Decatur 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 monitor
MonitorX-Sense
XR0A-iR Wi-Fi battery radon detector with a screen
- C-NRPP 2024/25: Not included
- Battery
- Wi-Fi
- Screen, app
Method: Alpha spectrometry
First reading: Within 24 hours
Short-term kitKidde
442020 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 3 days
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Decatur County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Decatur County
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Decatur County, Bordering counties
Counties bordering Decatur County
Calculated by Radon411- Radon levels in Sheridan County, KSEPA zone 1
100.0%at or above 4 pCi/L
Median 5.8 pCi/L · 9 tests · 13.3 points above Decatur County
- Radon levels in Furnas County, NEEPA zone 1
100.0%at or above 4 pCi/L
Median 5.6 pCi/L · 12 tests · 13.3 points above Decatur County
- Radon levels in Norton County, KSEPA zone 1
93.8%at or above 4 pCi/L
Median 7.3 pCi/L · 48 tests · 7.1 points above Decatur County
- Radon levels in Thomas County, KSEPA zone 1
56.3%at or above 4 pCi/L
Median 4.2 pCi/L · 48 tests · 30.4 points below Decatur County
- Radon levels in Rawlins County, KSEPA zone 1
50.0%at or above 4 pCi/L
Median 3.8 pCi/L · 18 tests · 36.7 points below Decatur County
- Radon levels in Red Willow County, NEEPA zone 1
48.0%at or above 4 pCi/L
Median 3.8 pCi/L · 150 tests · 38.7 points below Decatur County
Decatur County, Cities and towns
Cities and towns in Decatur County
About 2,716 people live in Decatur County by the Census Bureau's estimate for July 1, 2025, 46 fewer than in 2020 (−1.7%). Spread over its land, that is 3.0 people to the square mile. Oberlin alone is home to 1,606 of them, 59.1% of the total. CDC's 45 reported tests for 2021 work out to 16.6 per 1,000 residents (2025 estimate), close to Kansas' 23.5.
From Oberlin to Dresden, CDC publishes no figure by town: each reads Decatur County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Oberlin | 1,606 | −1.4% | 59.1% |
| Norcatur | 159 | −1.9% | 5.9% |
| Jennings | 79 | −2.5% | 2.9% |
| Claytonextends beyond Decatur County | 45 | −2.2% | Counted whole |
| Dresden | 42 | −4.5% | 1.5% |
5 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). A place that extends beyond Decatur County is counted whole, so it has no share.
Decatur County, Homes
Homes in Decatur County
Decatur County is a place of houses on their own lots: 90% of its 1,643 homes are detached single-family houses, against 72% across Kansas. The homes are older than Kansas' as a whole: half were built before 1954 (1975 for Kansas), and 58% date from before 1960. Owners live in 79% of the occupied homes (Kansas: 67%), so for most households a test and a fix are their own to order.
| Homes | Decatur County | Kansas |
|---|---|---|
| Housing units | 1,643 | 1,285,221 |
| Detached houses | 90% | 72% |
| In buildings of 5 or more | 2% | 13% |
| Mobile homes | 4% | 4% |
| Built before 1960 | 58% | 33% |
| Built since 2000 | 5% | 20% |
| Middle year built | 1954 | 1975 |
| 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.