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 Mahnomen County, Minnesota
EPA puts Mahnomen County in Zone 1, its highest radon zone, and only 11 radon tests from it are on file with CDC (2023). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
62.5%
19.1 pts above MN
- Mahnomen
- 62.5%
- Minnesota
- 43.4%
48 tests, 2008 to 2017
Median result
4.8pCi/L
Action level reached
- Mahnomen
- 4.8 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
48
84th of 85 by tests
- Mahnomen
- 48
- Hennepin
- 35,213
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in Minnesota
33 of 85
Middle half
- Mahnomen
- 62.5%
- Rock
- 83.8%
By share, of 85 with 30+ tests
Read a result for Mahnomen County
Starts at Mahnomen County's median, 4.8 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.8 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. Mahnomen County's median reported result, 2008 to 2017.
The data
Mahnomen County, At a glance
Mahnomen County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Mahnomen 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 Mahnomen County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 75.0% |
| 2015 | 52.0% |
| 2016 | 20.0% |
| 2017 | 8.6% |
| 2018 | 73.3% |
| 2019 | 40.0% |
| 2020 | 25.0% |
| 2021 | 100.0% |
| 2022 | 37.5% |
| 2023 | 54.5% |
2023: 54.5%. Across these years the share ran from 8.6% to 100.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 11 tests were reported to CDC for Mahnomen County over 2023, 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: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).
Mahnomen County, Compared
Mahnomen County radon figures, compared
Calculated by Radon411More than half: 62.5% of the 48 radon tests reported to CDC for Mahnomen County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 33rd of 85 Minnesota counties with 30 or more tests for the same period. That is 19.1 points above the 43.4% pooled from 87 Minnesota counties.
The newest figure, in 2023, counts only 11 tests (54.5% at or above 4 pCi/L), too few to compare, so this reading uses the 48-test figure.
The median result, 4.8 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 30.1 pCi/L. The rest split 18.8% under 2 pCi/L and 18.8% from 2 to 4 (Minnesota: 27.4% and 29.2%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 62.5% share point the same way here.
1 of its 4 bordering counties with figures ran higher, led by Polk County at 70.8%; Clearwater County reported 50.5%. Statewide for the same period, Rock County reported the highest share (83.8%) and Anoka County the lowest (17.4%).
The busiest year on file was 2017, with 35 tests reported; the quietest, 2021, had 1.
Nationally, every county with a figure for the same period pools to 35.7%; Mahnomen County sits 26.8 points above it.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Mahnomen County, State data
Minnesota's own radon test data
MeasuredWhat Minnesota's own agencies publish about radon tests in Mahnomen County, with their period. These are not CDC's figures and are never added to them.
MeasuredState figures, not CDC's
What the Minnesota Department of Health reports for Mahnomen County
Radon Testing (MN Public Health Data Access Portal): home radon tests reported voluntarily by private laboratories and licensed radon measurement professionals, counted by property. Period: 2016-2025.
Share with one or more tests at or above 4 pCi/L
45.9%
28 properties tested with one or more tests at or above 4 pCi/L
Median result
3.5 pCi/L
Average result
4.9 pCi/L
Tests behind these figures
6 properties tested a year on average
- MDH says these data do not include all of the radon tests conducted in Minnesota.
- Post-mitigation tests are excluded from the averages and the median; the percentages use each property's highest test.
- Each home is unique and can have very different results than a neighbor's home; the only way to know is to test.
- These figures describe tests reported to the Minnesota Department of Health in this area. They count a different set of tests than CDC's figures and are not a reading of any one home.
Measured: Minnesota Department of Health data, 2016-2025.
Mahnomen County, Geology
The ground under Mahnomen County
PredictedUSGS's geologic map puts all of Mahnomen County's mapped land in one class: high radon potential. The map puts 93.9% of Mahnomen County in the area it calls Central Lowland-Till Prairie and 6.0% in Central Lowland-Western Lake Section. USGS gives both a radon index of 14, in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Central Lowland-Till Prairie | Silty and clayey till derived from shale and sandstone. | High | 14 | 93.9% |
| Central Lowland-Western Lake Section | Sandy calcareous till derived from carbonate rocks. | High | 14 | 6.0% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Mahnomen County beside the ground around it
Mahnomen County has more high-potential ground than Minnesota as a whole: 100% of its land against 61.1%. Of the 4 counties that border it, none has as large a share of high-potential ground; Becker County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Mahnomen County, Local resources
Radon testing and mitigation in Mahnomen County
- MDH Indoor Air UnitMDH Indoor Air Unit, run by MN Dept. of Health, 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 Minnesota.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 Minnesota255 professionals are listed in Minnesota.
What Minnesota's program says
- Phone
- 651-201-4601
- health.indoorair@state.mn.us
- Licensing of radon professionals
The Radon Licensing Act requires anyone who performs a radon test or radon mitigation, in a building they do not own or lease, must be licensed by MDH.
- Disclosure when a home is sold or rented
The Minnesota Radon Awareness Act requires specific disclosure and education be provided to potential home buyers during residential real estate transactions in Minnesota.
What it means
Mahnomen County, Questions
Questions about radon in Mahnomen County
Are radon levels high in Mahnomen County?
In 2023, 54.5% of the radon tests reported to CDC for Mahnomen County, Minnesota were at or above 4 pCi/L, and the median reported pre-mitigation result was 5.1 pCi/L. Of 85 Minnesota counties with 30 or more tests for the same period, 32 reported a higher share; pooled, the state comes to 43.4%.
Which counties border Mahnomen County?
Mahnomen County borders 4 counties: Clearwater County, Norman County, Becker County and Polk County.
Products
Mahnomen County, Products
Testing a home in Mahnomen County
In Mahnomen County, 62.5% of 48 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 43.4% pooled across Minnesota. In Zone 1 the year-round level in Mahnomen 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
XR0B-SR battery digital radon monitor with an alarm
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Alpha spectrometry
First reading: Within 24 hours
Short-term kit
RA400 short-term liquid scintillation radon test kit, lab fee included
- Lab fee included
Method: Liquid scintillation
In home: 48 to 96 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Mahnomen County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Mahnomen County
Explore
Mahnomen County, Bordering counties
Counties bordering Mahnomen County
Calculated by Radon411- Radon levels in Polk CountyEPA zone 1
70.8%at or above 4 pCi/L
Median 6.7 pCi/L · 397 tests · 8.3 points above Mahnomen County
- Radon levels in Norman CountyEPA zone 1
58.4%at or above 4 pCi/L
Median 4.8 pCi/L · 154 tests · 4.1 points below Mahnomen County
- Radon levels in Becker CountyEPA zone 1
51.4%at or above 4 pCi/L
Median 4.0 pCi/L · 313 tests · 11.1 points below Mahnomen County
- Radon levels in Clearwater CountyEPA zone 2
50.5%at or above 4 pCi/L
Median 4.0 pCi/L · 91 tests · 12.0 points below Mahnomen County
Mahnomen County, Cities and towns
Cities and towns in Mahnomen County
About 5,153 people live in Mahnomen County by the Census Bureau's estimate for July 1, 2025, 220 fewer than in 2020 (−4.1%). Spread over its land, that is 9.2 people to the square mile. Its largest town, Mahnomen, has 1,181 residents, 22.9% of the total. Together its 3 incorporated places hold 32.0% of those residents; the other 68.0% live outside any of them. Reported testing is thin here: 48 tests over 2008 to 2017, or 9.3 for every 1,000 residents (2025 estimate), where Minnesota as a whole comes to 22.5.
From Mahnomen to Bejou, CDC publishes no figure by town: each reads Mahnomen County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Mahnomen | 1,181 | −4.3% | 22.9% |
| Waubun | 389 | −4.7% | 7.5% |
| Bejou | 81 | −4.7% | 1.6% |
3 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).
Mahnomen County, Homes
Homes in Mahnomen County
Mahnomen County is a place of houses on their own lots: 79% of its 2,552 homes are detached single-family houses, against 66% across Minnesota. Half of its homes were built before 1975, close to Minnesota's 1978: 32% date from before 1960 and 17% from 2000 or later. 72% of occupied homes are lived in by their owner (Minnesota: 72%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Mahnomen County | Minnesota |
|---|---|---|
| Housing units | 2,552 | 2,519,538 |
| Detached houses | 79% | 66% |
| In buildings of 5 or more | 7% | 19% |
| Mobile homes | 10% | 3% |
| Built before 1960 | 32% | 29% |
| Built since 2000 | 17% | 22% |
| Middle year built | 1975 | 1978 |
| Owner-occupied | 72% | 72% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.