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 Ransom County, North Dakota
EPA puts Ransom County in Zone 1, its highest radon zone, and high results are common there: 61.6% of the 151 radon tests reported to CDC (2008 to 2017, laboratory totals) came back 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
61.6%
2.3 pts above ND
- Ransom
- 61.6%
- ND
- 59.3%
151 tests, 2008 to 2017
Median result
5.8pCi/L
Action level reached
- Ransom
- 5.8 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
151
9th of 29 by tests
- Ransom
- 151
- Burleigh
- 1,558
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 ND
18 of 29
Middle half
- Ransom
- 61.6%
- Pembina
- 82.5%
By share, of 29 with 30+ tests
Read a result for Ransom County
Starts at Ransom County's median, 5.8 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 5.8 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. Ransom County's median reported result, 2008 to 2017.
The data
Ransom County, At a glance
Ransom County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Ransom 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 Ransom County, 2008 to 2017, laboratory
Under 2 pCi/L: 18%2 to 4 pCi/L: 20%4 pCi/L and above: 62%
Of 151 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 27 | 17.9% |
| 2 to 4 pCi/L | 31 | 20.5% |
| 4 pCi/L and above | 93 | 61.6% |
What these figures count
These are the 151 tests reported to CDC for Ransom County over 2008 to 2017 (laboratory totals), 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: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).
Ransom County, Compared
Ransom County radon figures, compared
Calculated by Radon411More than half: 61.6% of the 151 radon tests reported to CDC for Ransom County over the 2008 to 2017 laboratory totals read at least 4 pCi/L. That places it 18th of 29 North Dakota counties with 30 or more tests for the same period. That is 2.3 points above the 59.3% pooled from 53 North Dakota counties.
The median result, 5.8 pCi/L, sits above EPA's 4 pCi/L action level, and the top reported result was 104.6 pCi/L. The rest split 17.9% under 2 pCi/L and 20.5% from 2 to 4 (North Dakota: 18.3% and 22.4%). Zone 1 on EPA's map (predicted average above 4 pCi/L) and a 61.6% share point the same way here.
3 of its 5 bordering counties with figures ran higher, led by LaMoure County at 70.5%; Richland County reported 43.0%. Statewide for the same period, Pembina County reported the highest share (82.5%) and Williams County the lowest (33.8%).
CDC's ten-year totals for Ransom County went from 178 tests (2005 to 2014) to 151 (2008 to 2017), the share going from 59.6% to 61.6%.
Nationally, every county with a figure for the same period pools to 35.7%; Ransom County sits 25.9 points above it.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Ransom County, Geology
The ground under Ransom County
PredictedUSGS's geologic map puts all of Ransom County's mapped land in one class: high radon potential. The map puts 70.7% of Ransom County in the area it calls Great Plains (Glaciated) and 29.3% in Glacial Lakes. USGS gives the first a radon index of 13 and the second 14, both 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 | 70.7% |
| Glacial Lakes | Silt and clay deposits of Glacial Lake Agassiz derived from Cretaceous shales containing higher than average amounts of uranium. | High | 14 | 29.3% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Ransom County beside the ground around it
On high-potential ground Ransom County is close to North Dakota as a whole: 100% of its land against 98.9%. Of the 6 counties that border it, none has as large a share of high-potential ground; Barnes County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Ransom County, Local resources
Radon testing and mitigation in Ransom 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
Ransom County, Questions
Questions about radon in Ransom County
Are radon levels high in Ransom County?
Over the 2008 to 2017 laboratory totals, 61.6% of the radon tests reported to CDC for Ransom County, North Dakota were at or above 4 pCi/L, and the median reported pre-mitigation result was 5.8 pCi/L. Of 29 North Dakota counties with 30 or more tests for the same period, 17 reported a higher share; pooled, the state comes to 59.3%.
Which counties border Ransom County?
Ransom County borders 6 counties: Sargent County, Barnes County, Richland County, Cass County, LaMoure County and Dickey County.
Products
Ransom County, Products
Testing a home in Ransom County
In Ransom County, 61.6% of 151 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 59.3% pooled across North Dakota. In Zone 1 the year-round level in Ransom 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
MonitorINKBIRD
INK-RD3 battery radon monitor with an e-ink screen
- C-NRPP 2024/25: Not included
- Battery
- Screen
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
Ransom County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Ransom County
Explore
Ransom County, Bordering counties
Counties bordering Ransom County
Calculated by Radon411- Radon levels in Sargent CountyEPA zone 1
75.0%at or above 4 pCi/L
Median 7.2 pCi/L · 24 tests · 13.4 points above Ransom County
- Radon levels in LaMoure CountyEPA zone 1
70.5%at or above 4 pCi/L
Median 5.2 pCi/L · 44 tests · 8.9 points above Ransom County
- Radon levels in Barnes CountyEPA zone 1
67.5%at or above 4 pCi/L
Median 5.6 pCi/L · 83 tests · 5.9 points above Ransom County
- Radon levels in Dickey CountyEPA zone 1
67.1%at or above 4 pCi/L
Median 4.8 pCi/L · 70 tests · 5.5 points above Ransom County
- Radon levels in Cass CountyEPA zone 1
57.5%at or above 4 pCi/L
Median 4.7 pCi/L · 862 tests · 4.1 points below Ransom County
- Radon levels in Richland CountyEPA zone 1
43.0%at or above 4 pCi/L
Median 3.6 pCi/L · 93 tests · 18.6 points below Ransom County
Ransom County, Cities and towns
Cities and towns in Ransom County
About 5,617 people live in Ransom County by the Census Bureau's estimate for July 1, 2025, 83 fewer than in 2020 (−1.5%). Spread over its land, that is 6.5 people to the square mile. Its largest town, Lisbon, has 2,184 residents, 38.9% of the total. Testing is reported here more often than across the state: CDC's 151 reported tests for 2008 to 2017 come to 26.9 for every 1,000 residents (2025 estimate), against 8.3 for North Dakota.
From Lisbon to Elliott, CDC publishes no figure by town: each reads Ransom County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Lisbon | 2,184 | −0.8% | 38.9% |
| Enderlinextends beyond Ransom County | 860 | −2.4% | Counted whole |
| Fort Ransom | 95 | +4.4% | 1.7% |
| Sheldon | 94 | −2.1% | 1.7% |
| Elliott | 22 | Level | 0.4% |
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 Ransom County is counted whole, so it has no share.
Ransom County, Homes
Homes in Ransom County
Ransom County is a place of houses on their own lots: 77% of its 2,538 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 1964 (1981 for North Dakota), and 47% date from before 1960. Owners live in 76% of the occupied homes (North Dakota: 63%), so for most households a test and a fix are their own to order.
| Homes | Ransom County | North Dakota |
|---|---|---|
| Housing units | 2,538 | 374,866 |
| Detached houses | 77% | 57% |
| In buildings of 5 or more | 12% | 25% |
| Mobile homes | 7% | 7% |
| Built before 1960 | 47% | 24% |
| Built since 2000 | 14% | 31% |
| Middle year built | 1964 | 1981 |
| Owner-occupied | 76% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.