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 Cavalier County, North Dakota
EPA puts Cavalier County in Zone 1, its highest radon zone, and only 28 radon tests from it are on file with CDC (2008 to 2017, laboratory totals). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
45.5%
8.5 pts below ND
- Cavalier
- 45.5%
- ND
- 54.0%
66 tests, 2005 to 2014
Median result
3.7pCi/L
Below action level
- Cavalier
- 3.7 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2005 to 2014
Tests reported
66
18th of 39 by tests
- Cavalier
- 66
- Burleigh
- 1,312
Reported to CDC before any fix, 2005 to 2014
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Rank in ND
32 of 39
Lowest quarter
- Cavalier
- 45.5%
- Billings
- 90.9%
By share, of 39 with 30+ tests
Read a result for Cavalier County
Starts at Cavalier County's median, 3.7 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 3.7 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. Cavalier County's median reported result, 2005 to 2014.
The data
Cavalier County, At a glance
Cavalier County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Cavalier 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 Cavalier County, 2008 to 2017, laboratory
CDC holds 28 reported tests for Cavalier County over the 2008 to 2017 laboratory totals, with a median of 3.9 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Cavalier County beside the counties around it is how this page reads it.
What these figures count
Only 28 tests were reported to CDC for Cavalier County over 2008 to 2017 (laboratory totals), 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: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).
Cavalier County, Compared
Cavalier County radon figures, compared
Calculated by Radon411In Cavalier County, about 5 in 10 reported tests over the 2005 to 2014 laboratory totals (30 of 66) were at or above EPA's action level. Against the national pool of 36.0%, the gap is 9.5 points higher. Across 53 North Dakota counties pooled together, 54.0% of tests reached that level, so Cavalier County runs 8.5 points below its state.
The newest figure, over the 2008 to 2017 laboratory totals, counts only 28 tests (50.0% at or above 4 pCi/L), too few to compare, so this reading uses the 66-test figure.
Of 4 neighbours with a figure, all 4 reported a larger share at or above 4 pCi/L; the spread is 51.3% (Towner County) to 76.6% (Walsh County). By share, Cavalier County is 32nd of 39 North Dakota counties with 30 or more tests for the same period.
Half the tests came in under 3.7 pCi/L and half over it; the single highest reached 32.2 pCi/L. Below the action level, 16 tests (24.2%) came in under 2 pCi/L, against 22.0% statewide, and 20 tests (30.3%) fell between 2 and 4, against 23.9% statewide.
Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 45.5% share point the same way here. USGS geology rates 100% of the county's land high radon potential.
CDC's ten-year totals for Cavalier County went from 66 tests (2005 to 2014) to 28 (2008 to 2017), the share going from 45.5% to 50.0%.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Cavalier County, Geology
The ground under Cavalier County
PredictedUSGS's geologic map puts all of Cavalier County's mapped land in one class: high radon potential. 98.2% of it lies in the area the map calls Great Plains (Glaciated), 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 |
|---|---|---|---|---|
| Great Plains (Glaciated) | Glacial deposits derived from Cretaceous shales containing higher than average amounts of uranium. | High | 13 | 98.2% |
| Glacial Lakes | Silt and clay deposits of Glacial Lake Agassiz derived from Cretaceous shales containing higher than average amounts of uranium. | High | 14 | 1.7% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Cavalier County beside the ground around it
On high-potential ground Cavalier County is close to North Dakota as a whole: 99.9% of its land against 98.9%. Of the 4 counties that border it, 3 have more high-potential ground, Ramsey County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Cavalier County, Local resources
Radon testing and mitigation in Cavalier County
- North Dakota's radon programNorth Dakota Department of Environmental QualityNorth Dakota's radon program offers free or discounted test kits, and answers questions about testing and mitigation in North Dakota.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
Notice: The DEQ is out of free radon test kits.
- Compare kits
- Professionals in North Dakota47 professionals are listed in North Dakota.
What North Dakota's program says
- Phone
- 701-328-5166
- jOtto@nd.gov
What it means
Cavalier County, Questions
Questions about radon in Cavalier County
Are radon levels high in Cavalier County?
Over the 2008 to 2017 laboratory totals, 50.0% of the radon tests reported to CDC for Cavalier County, North Dakota were at or above 4 pCi/L, and the median reported pre-mitigation result was 3.9 pCi/L. Of 39 North Dakota counties with 30 or more tests for the same period, 31 reported a higher share; pooled, the state comes to 54.0%.
Which counties border Cavalier County?
Cavalier County borders 4 counties: Towner County, Ramsey County, Pembina County and Walsh County.
Products
Cavalier County, Products
Testing a home in Cavalier County
In Cavalier County, 45.5% of 66 tests reported to CDC over the 2005 to 2014 laboratory totals reached 4 pCi/L, against 54.0% pooled across North Dakota. In Zone 1 the year-round level in Cavalier 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
Hello Radon C battery radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Screen
Method: Alpha spectrometry
First reading: Within 24 hours
Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 days
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Cavalier County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Cavalier County
Explore
Cavalier County, Bordering counties
Counties bordering Cavalier County
Calculated by Radon411- Radon levels in Walsh CountyEPA zone 1
76.6%at or above 4 pCi/L
Median 8.7 pCi/L · 145 tests · 31.1 points above Cavalier County
- Radon levels in Ramsey CountyEPA zone 1
73.3%at or above 4 pCi/L
Median 6.5 pCi/L · 131 tests · 27.8 points above Cavalier County
- Radon levels in Pembina CountyEPA zone 1
73.3%at or above 4 pCi/L
Median 7.8 pCi/L · 60 tests · 27.8 points above Cavalier County
- Radon levels in Towner CountyEPA zone 1
51.3%at or above 4 pCi/L
Median 4.9 pCi/L · 39 tests · 5.8 points above Cavalier County
Cavalier County, Cities and towns
Cities and towns in Cavalier County
Cavalier County has been losing residents: from 3,697 in 2020 to 3,497 on July 1, 2025, a fall of 5.4% by the Census Bureau's estimates. Spread over its land, that is 2.3 people to the square mile. Langdon alone is home to 1,809 of them, 51.7% of the total. Testing is reported here more often than across the state: CDC's 66 reported tests for 2005 to 2014 come to 18.9 for every 1,000 residents (2025 estimate), against 8.2 for North Dakota.
From Langdon to Loma, CDC publishes no figure by town: each reads Cavalier County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Langdon | 1,809 | −4.7% | 51.7% |
| Munich | 181 | −6.7% | 5.2% |
| Osnabrock | 93 | −8.8% | 2.7% |
| Milton | 39 | −7.1% | 1.1% |
| Alsen | 29 | −6.5% | 0.8% |
| Nekoma | 29 | −6.5% | 0.8% |
| Sarlesextends beyond Cavalier County | 21 | −4.5% | Counted whole |
| Calvin | 15 | −6.3% | 0.4% |
| Wales | 8 | −11.1% | 0.2% |
| Calio | 7 | Level | 0.2% |
| Hannah | 7 | −12.5% | 0.2% |
| Loma | 7 | Level | 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 Cavalier County is counted whole, so it has no share.
Cavalier County, Homes
Homes in Cavalier County
Cavalier County is a place of houses on their own lots: 79% of its 2,115 homes are detached single-family houses, against 57% across North Dakota. The homes are older than North Dakota's as a whole: half were built before 1970 (1981 for North Dakota), and 35% date from before 1960. Owners live in 83% of the occupied homes (North Dakota: 63%), so for most households a test and a fix are their own to order.
| Homes | Cavalier County | North Dakota |
|---|---|---|
| Housing units | 2,115 | 374,866 |
| Detached houses | 79% | 57% |
| In buildings of 5 or more | 6% | 25% |
| Mobile homes | 4% | 7% |
| Built before 1960 | 35% | 24% |
| Built since 2000 | 8% | 31% |
| Middle year built | 1970 | 1981 |
| Owner-occupied | 83% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.