Short-term kitempowerDX
Standard Radon Test short-term mail-in radon test kit
- Lab fee included
Method: Passive sampler
In home: 48 to 96 hours
Locations and reports
Radon Levels in Sumner County, Kansas
EPA puts Sumner County in Zone 2, its middle radon zone, and 29.1% of its 79 reported radon tests (2022) were at or above 4 pCi/L. Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
29.1%
2.9 pts below KS
- Sumner
- 29.1%
- Kansas
- 32.0%
79 tests, 2022
Median result
2.3pCi/L
Below action level
- Sumner
- 2.3 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2022
Tests reported
79
21st of 38 by tests
- Sumner
- 79
- Johnson
- 5,240
Reported to CDC before any fix, 2022
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Rank in Kansas
25 of 38
Middle half
- Sumner
- 29.1%
- Mitchell
- 57.4%
By share, of 38 with 30+ tests
Read a result for Sumner County
Starts at Sumner County's median, 2.3 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.3 pCi/L
Between 2 and 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is between 2 and 4 pCi/L. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. Sumner County's median reported result, 2022.
The data
Sumner County, At a glance
Sumner County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Sumner County is a
USGS geologic potential: Moderate across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Sumner County, 2022
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2016 | 30.8% |
| 2017 | 35.6% |
| 2018 | 44.2% |
| 2019 | 32.8% |
| 2020 | 30.0% |
| 2021 | 31.6% |
| 2022 | 29.1% |
2022: 29.1%. Across these years the share ran from 29.1% to 44.2%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 79 tests reported to CDC for Sumner County over 2022, many from homes being sold or already suspected of a problem: they describe the county's reported tests, not this house.
Measured: CDC tracking data. Figure above: 2022. Measured data period: 2016 to 2022 (every CDC figure on file).
Sumner County, Compared
Sumner County radon figures, compared
Calculated by Radon411Sumner County's 79 reported tests in 2022 had a middle value of 2.3 pCi/L and a maximum of 13.4 pCi/L, and 29.1% reached 4 pCi/L. Kansas as a whole (96 Kansas counties, pooled) comes to 32.0%: 2.9 points higher than here.
Among its state's counties it ranks 25th of 38 Kansas counties with 30 or more tests for the same period. Statewide for the same period, Mitchell County reported the highest share (57.4%) and Crawford County the lowest (5.9%).
Below the action level, 31 tests (39.2%) came in under 2 pCi/L, against 45.8% statewide, and 25 tests (31.6%) fell between 2 and 4, against 22.1% statewide. The busiest year on file was 2021, with 285 tests reported; the quietest, 2019, had 58.
EPA's 1993 zone map puts Sumner County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 100% of the county's land moderate radon potential.
Next door, the shares run from 18.4% in Sedgwick County to 39.8% in Cowley County, with Butler County and Sedgwick County below Sumner County. Over 7 years of annual figures the share held within 2 points, from 30.8% in 2016 to 29.1% in 2022; its peak was 44.2% in 2018.
Sumner CountyKansas, pooled
| Year | Tests | Sumner County, at or above 4 pCi/L | Kansas, pooled |
|---|---|---|---|
| 2016 | 65 | 30.8% | 35.4% |
| 2017 | 59 | 35.6% | 37.3% |
| 2018 | 77 | 44.2% | 37.3% |
| 2019 | 58 | 32.8% | 33.7% |
| 2020 | 60 | 30.0% | 31.3% |
| 2021 | 285 | 31.6% | 31.8% |
| 2022 | 79 | 29.1% | 32.0% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Sumner County, Geology
The ground under Sumner County
PredictedMost of the ground under Sumner County is one class on USGS's geologic map: 99.7% of its land is moderate radon potential, with 0.3% low. All of it lies in the area the map calls Glaciated Area, to which USGS gives a radon index of 9, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Glaciated Area | Glacial till underlain by Pennsylvanian and Permian marine and nonmarine sedimentary shale, sandstone, limestone, coal. | Moderate | 9 | 99.7% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Sumner County beside the ground around it
Across Kansas 59.9% of the land is rated high; none of Sumner County's is. Of the 7 counties that border it, 2 have more high-potential ground, Kingman County the most at 51.8%.
The map rates the ground, not the air in any home.
Local help
Sumner County, Local resources
Radon testing and mitigation in Sumner 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.
Listed radon professionals by town: Mulvane
What Kansas's program says
- Phone
- (800) 693-5343
What it means
Sumner County, Questions
Questions about radon in Sumner County
Are radon levels high in Sumner County?
In 2022, 29.1% of the radon tests reported to CDC for Sumner County, Kansas were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.3 pCi/L. Of 38 Kansas counties with 30 or more tests for the same period, 24 reported a higher share; pooled, the state comes to 32.0%.
Which counties border Sumner County?
Sumner County borders 7 counties: Sedgwick County, KS, Kay County, OK, Grant County, OK, Harper County, KS, Cowley County, KS, Kingman County, KS and Butler County, KS.
Products
Sumner County, Products
Testing a home in Sumner County
In Sumner County, 29.1% of 79 tests reported to CDC in 2022 reached 4 pCi/L, against 32.0% pooled across Kansas. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Sumner County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
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
Monitor
EcoQube Wi-Fi continuous radon monitor
- C-NRPP 2024/25: Approved
- Plug-in
- Wi-Fi
- App only
Method: Ion chamber
First reading: Within 10 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Sumner County, Bordering counties
Counties bordering Sumner County
Calculated by Radon411- Radon levels in Cowley County, KSEPA zone 2
39.8%at or above 4 pCi/L
Median 3.3 pCi/L · 118 tests · 10.7 points above Sumner County
- Radon levels in Butler County, KSEPA zone 2
25.5%at or above 4 pCi/L
Median 2.1 pCi/L · 550 tests · 3.6 points below Sumner County
- Radon levels in Kingman County, KSEPA zone 1
19.0%at or above 4 pCi/L
Median 2.1 pCi/L · 21 tests · 10.1 points below Sumner County
- Radon levels in Sedgwick County, KSEPA zone 2
18.4%at or above 4 pCi/L
Median 1.3 pCi/L · 4,911 tests · 10.7 points below Sumner County
- Radon levels in Harper County, KSEPA zone 2
16.7%at or above 4 pCi/L
Median 0.9 pCi/L · 6 tests · 12.4 points below Sumner County
- Radon levels in Kay County, OKEPA zone 3
No CDC figure for 2022; its page reads it against its own neighbours.
- Radon levels in Grant County, OKEPA zone 3
No CDC figure for 2022; its page reads it against its own neighbours.
Sumner County, Cities and towns
Cities and towns in Sumner County
Sumner County's population has barely moved since 2020: 22,312 residents on July 1, 2025 against 22,341 then, by the Census Bureau's estimates. That works out to 19 people per square mile of land. Its largest town, Wellington, has 7,541 residents, 33.8% of the total. Reported testing is thin here: 79 tests over 2022, or 3.5 for every 1,000 residents (2025 estimate), where Kansas as a whole comes to 6.2.
From Wellington to Hunnewell, CDC publishes no figure by town: each reads Sumner County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Wellington | 7,541 | −1.8% | 33.8% |
| Mulvaneextends beyond Sumner County | 7,030 | +11.6% | Counted whole |
| Belle Plaine | 1,442 | −2.1% | 6.5% |
| Conway Springs | 1,141 | +4.2% | 5.1% |
| Oxford | 1,038 | −0.9% | 4.7% |
| Caldwell | 1,000 | −2.6% | 4.5% |
| Argonia | 447 | −2.4% | 2.0% |
| South Haven | 329 | +0.3% | 1.5% |
| Geuda Springsextends beyond Sumner County | 158 | +2.6% | Counted whole |
| Mayfield | 71 | Level | 0.3% |
| Milan | 48 | Level | 0.2% |
| Hunnewell | 47 | +2.2% | 0.2% |
12 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 Sumner County is counted whole, so it has no share.
Sumner County, Homes
Homes in Sumner County
Sumner County is a place of houses on their own lots: 81% of its 10,395 homes are detached single-family houses, against 72% across Kansas. The homes are older than Kansas' as a whole: half were built before 1966 (1975 for Kansas), and 46% date from before 1960. 74% of occupied homes are lived in by their owner (Kansas: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Sumner County | Kansas |
|---|---|---|
| Housing units | 10,395 | 1,285,221 |
| Detached houses | 81% | 72% |
| In buildings of 5 or more | 4% | 13% |
| Mobile homes | 9% | 4% |
| Built before 1960 | 46% | 33% |
| Built since 2000 | 13% | 20% |
| Middle year built | 1966 | 1975 |
| Owner-occupied | 74% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.