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 Ottawa County, Kansas
EPA puts Ottawa County in Zone 1, its highest radon zone, and only 25 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
31.7%
0.1 pts below KS
- Ottawa
- 31.7%
- Kansas
- 31.8%
180 tests, 2021
Median result
2.6pCi/L
Below action level
- Ottawa
- 2.6 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2021
Tests reported
180
27th of 62 by tests
- Ottawa
- 180
- 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
40 of 62
Middle half
- Ottawa
- 31.7%
- Norton
- 93.8%
By share, of 62 with 30+ tests
Read a result for Ottawa County
Starts at Ottawa County's median, 2.6 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.6 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. Ottawa County's median reported result, 2021.
The data
Ottawa County, At a glance
Ottawa County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Ottawa 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 Ottawa County, 2022
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2016 | 57.7% |
| 2017 | 40.0% |
| 2018 | 43.9% |
| 2019 | 48.4% |
| 2020 | 39.2% |
| 2021 | 31.7% |
| 2022 | 32.0% |
2022: 32.0%. Across these years the share ran from 31.7% to 57.7%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 25 tests were reported to CDC for Ottawa 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).
Ottawa County, Compared
Ottawa County radon figures, compared
Calculated by Radon411In Ottawa County, about 3 in 10 reported tests in 2021 (57 of 180) were at or above EPA's action level. Against the national pool of 24.4%, the gap is 7.3 points higher. Across 96 Kansas counties pooled together, 31.8% of tests reached that level, so Ottawa County runs 0.1 points below its state.
The newest figure, in 2022, counts only 25 tests (32.0% at or above 4 pCi/L), too few to compare, so this reading uses the 180-test figure.
Of 6 neighbours with a figure, all 6 reported a larger share at or above 4 pCi/L; the spread is 37.0% (Saline County) to 63.6% (Lincoln County). By share, Ottawa County is 40th of 62 Kansas counties with 30 or more tests for the same period.
Year by year, 2017 opened at 40.0% and 2021 closed at 31.7% (down 8.3 points), with 2019 the high at 48.4%. Half the tests came in under 2.6 pCi/L and half over it; the single highest reached 32.2 pCi/L. Below the action level, 60 tests (33.3%) came in under 2 pCi/L, against 45.3% statewide, and 63 tests (35.0%) fell between 2 and 4, against 22.9% statewide.
Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 31.7% share point the same way here. USGS geology rates 100% of the county's land high radon potential. CDC also counts 6 tests taken after mitigation in Ottawa County for the same period: tests in homes where a fix was already in.
The busiest year on file was 2021, with 180 tests reported; the quietest, 2022, had 25.
Ottawa CountyKansas, pooled
| Year | Tests | Ottawa County, at or above 4 pCi/L | Kansas, pooled |
|---|---|---|---|
| 2017 | 30 | 40.0% | 37.3% |
| 2018 | 41 | 43.9% | 37.3% |
| 2019 | 31 | 48.4% | 33.7% |
| 2020 | 51 | 39.2% | 31.3% |
| 2021 | 180 | 31.7% | 31.8% |
Pooled shares: Radon411's sum of CDC's county counts for one period.
Ottawa County, Geology
The ground under Ottawa County
PredictedUSGS's geologic map puts all of Ottawa County's mapped land in one class: high radon potential. All of it lies in the area the map calls Smoky Hills, 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 |
|---|---|---|---|---|
| Smoky Hills | Cretaceous marine sandstone, shale, and siltstone covered by discontinuous loess deposits. | High | 12 | 99.7% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Ottawa County beside the ground around it
Ottawa 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; Cloud County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Ottawa County, Local resources
Radon testing and mitigation in Ottawa 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
Ottawa County, Questions
Questions about radon in Ottawa County
Are radon levels high in Ottawa County?
In 2022, 32.0% of the radon tests reported to CDC for Ottawa County, Kansas were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.3 pCi/L. Of 62 Kansas counties with 30 or more tests for the same period, 39 reported a higher share; pooled, the state comes to 31.8%.
Which counties border Ottawa County?
Ottawa County borders 6 counties: Cloud County, Saline County, Lincoln County, Clay County, Dickinson County and Mitchell County.
Products
Ottawa County, Products
Testing a home in Ottawa County
In Ottawa County, 31.7% of 180 tests reported to CDC in 2021 reached 4 pCi/L, against 31.8% pooled across Kansas. In Zone 1 the year-round level in Ottawa 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
Monitor
EcoQube Flex battery digital radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Bluetooth
- Alarm
- Screen, app
Method: Ion chamber
First reading: Within 15 minutes
Short-term kit
PicoCan short-term charcoal canister radon test
- Lab fee included
Method: Charcoal
In home: 48 to 96 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Ottawa County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Ottawa County
Explore
Ottawa County, Bordering counties
Counties bordering Ottawa County
Calculated by Radon411- Radon levels in Lincoln CountyEPA zone 1
63.6%at or above 4 pCi/L
Median 4.5 pCi/L · 33 tests · 31.9 points above Ottawa County
- Radon levels in Cloud CountyEPA zone 1
60.2%at or above 4 pCi/L
Median 4.4 pCi/L · 264 tests · 28.5 points above Ottawa County
- Radon levels in Mitchell CountyEPA zone 1
55.9%at or above 4 pCi/L
Median 4.8 pCi/L · 177 tests · 24.2 points above Ottawa County
- Radon levels in Clay CountyEPA zone 1
54.0%at or above 4 pCi/L
Median 4.5 pCi/L · 378 tests · 22.3 points above Ottawa County
- Radon levels in Dickinson CountyEPA zone 1
37.3%at or above 4 pCi/L
Median 2.5 pCi/L · 330 tests · 5.6 points above Ottawa County
- Radon levels in Saline CountyEPA zone 1
37.0%at or above 4 pCi/L
Median 2.8 pCi/L · 1,920 tests · 5.3 points above Ottawa County
Ottawa County, Cities and towns
Cities and towns in Ottawa County
Ottawa County's population has barely moved since 2020: 5,744 residents on July 1, 2025 against 5,729 then, by the Census Bureau's estimates. Spread over its land, that is 8.0 people to the square mile. Its largest town, Minneapolis, has 1,907 residents, 33.2% of the total. Together its 5 incorporated places hold 55.9% of those residents; the other 44.1% live outside any of them. CDC's 180 reported tests for 2021 work out to 31.3 per 1,000 residents (2025 estimate), close to Kansas' 23.5.
From Minneapolis to Culver, CDC publishes no figure by town: each reads Ottawa County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Minneapolis | 1,907 | −1.6% | 33.2% |
| Bennington | 637 | +2.7% | 11.1% |
| Delphos | 294 | −2.0% | 5.1% |
| Tescott | 260 | −1.5% | 4.5% |
| Culver | 112 | −0.9% | 1.9% |
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).
Ottawa County, Homes
Homes in Ottawa County
Ottawa County is a place of houses on their own lots: 87% of its 2,684 homes are detached single-family houses, against 72% across Kansas. The homes are older than Kansas' as a whole: half were built before 1964 (1975 for Kansas), and 46% date from before 1960. Owners live in 78% of the occupied homes (Kansas: 67%), so for most households a test and a fix are their own to order.
| Homes | Ottawa County | Kansas |
|---|---|---|
| Housing units | 2,684 | 1,285,221 |
| Detached houses | 87% | 72% |
| In buildings of 5 or more | 2% | 13% |
| Mobile homes | 3% | 4% |
| Built before 1960 | 46% | 33% |
| Built since 2000 | 17% | 20% |
| Middle year built | 1964 | 1975 |
| Owner-occupied | 78% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.