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 Faulk County, South Dakota
EPA puts Faulk County in Zone 1, its highest radon zone, and only 1 radon test from it is 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
Highest bordering
61.8%
Edmunds County
- Edmunds
- 61.8%
- Brown
- 59.6%
2 of 6 neighbours have 30+ tests, 2006 to 2015
Nearest county
61.8%
Edmunds County, 24 miles
- Edmunds
- 61.8%
- SD
- 58.8%
Share at 4+ pCi/L, 68 tests, 2006 to 2015
Ground above low
100.0%
1.0 pts above SD
- Faulk
- 100.0%
- SD
- 99.0%
Share of land USGS rates moderate or high potential
Tests reported
1
Too few for a share
- Faulk
- 1
- Needed
- 30
2008 to 2017, laboratory
EPA radon zone
Zone 1
Highest potential
- Zone 1
- 2
- 3
1 highest, 3 lowest
EPA predicts over 4 pCi/L indoors
Read a result for Faulk County
Starts at EPA's action level
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.0 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.
The data
Faulk County, At a glance
Faulk County at a glance
Predicted: EPA radon zone
EPA Zone 1: highest predicted potential
EPA puts all of Faulk 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 Faulk County, 2008 to 2017, laboratory
CDC holds 1 reported test for Faulk County over the 2008 to 2017 laboratory totals, a result of 32.2 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Faulk County beside the counties around it is how this page reads it.
What these figures count
Only 1 test was reported to CDC for Faulk 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).
Faulk County, Compared
Faulk County radon figures, compared
Calculated by Radon411CDC's largest figure for Faulk County rests on 1 test over the 2008 to 2017 laboratory totals, 1 of them at or above 4 pCi/L, so each test moves its share by 100.0 points and no rank or comparison is drawn from it. Results reached as high as 32.2 pCi/L, with a middle value of 32.2 pCi/L.
Of the counties bordering it, 2 have a figure over the 2006 to 2015 laboratory totals: Edmunds County reported the largest share at or above 4 pCi/L, 61.8%, and Brown County the smallest, 59.6%. Farther out, Beadle County (62 miles away) at 63.0%, Hughes County (63 miles away) at 66.7% and Brule County (93 miles away) at 62.5% have figures too. Pooled across 63 South Dakota counties, 58.8% of reported tests reached that level; across every county in the country with a figure, 36.3%.
Statewide for the same period, Bon Homme County reported the highest share (79.5%) and Davison County the lowest (47.9%). EPA's 1993 map puts Faulk County in Zone 1, the map's highest label: a predicted county average above 4 pCi/L. USGS geology rates 100% of the county's land high radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Faulk County, Geology
The ground under Faulk County
PredictedUSGS's geologic map puts all of Faulk County's mapped land in one class: high radon potential. All of it lies in the area the map calls Missouri Coteau/James River Lowland/Coteau des Prairies, to which USGS gives 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 |
|---|---|---|---|---|
| Missouri Coteau/James River Lowland/Coteau des Prairies | Glacial drift derived largely from Cretaceous marine shale. | High | 14 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Faulk County beside the ground around it
Faulk County has more high-potential ground than South Dakota as a whole: 100% of its land against 56.7%. Of the 6 counties that border it, none has as large a share of high-potential ground; Edmunds County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Faulk County, Local resources
Radon testing and mitigation in Faulk County
- South Dakota's radon programDepartment of Agriculture and Natural ResourcesSouth Dakota's radon program offers free or discounted test kits, and answers questions about testing and mitigation in South Dakota.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
The Department of Agriculture and Natural Resources (DANR) will provide 500 free Radon test kits to South Dakota Residents.
- Compare kits
- Professionals in South Dakota5 professionals are listed in South Dakota.
What South Dakota's program says
- Phone
- 1-800-438-3367
What it means
Faulk County, Questions
Questions about radon in Faulk County
Are radon levels high in Faulk County?
Over the 2008 to 2017 laboratory totals, 100.0% of the radon tests reported to CDC for Faulk County, South Dakota were at or above 4 pCi/L, and the median reported pre-mitigation result was 32.2 pCi/L. Of the counties bordering it, 2 have a figure over the 2006 to 2015 laboratory totals: Edmunds County reported the largest share at or above 4 pCi/L, 61.8%, and Brown County the smallest, 59.6%.
Which counties border Faulk County?
Faulk County borders 6 counties: Edmunds County, Spink County, Potter County, Hand County, Hyde County and Brown County.
Products
Faulk County, Products
Testing a home in Faulk County
No CDC figure names Faulk County; the nearest county with one, Edmunds County (24 miles away), reported 61.8% of its tests at or above 4 pCi/L over the 2006 to 2015 laboratory totals, the only reading nearby until a test of this home. In Zone 1 the year-round level in Faulk 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
MonitorKidde
Radon Detector (RAB) battery digital radon detector with an alarm
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
First reading: Within 12 hours
Short-term kit
Air Chek Short-Term radon test kit you hang, lab fee included
- Lab fee included
In home: 72 to 168 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Faulk County is in EPA Zone 1, the highest predicted radon potential. Best radon monitors for Zone 1 counties like Faulk County
Explore
Faulk County, Bordering counties
Counties bordering Faulk County
Calculated by Radon411- Radon levels in Hand CountyEPA zone 1
80.0%at or above 4 pCi/L
Median 4.8 pCi/L · 10 tests
- Radon levels in Hyde CountyEPA zone 1
80.0%at or above 4 pCi/L
Median 4.9 pCi/L · 5 tests
- Radon levels in Edmunds CountyEPA zone 1
61.8%at or above 4 pCi/L
Median 5.0 pCi/L · 68 tests
- Radon levels in Brown CountyEPA zone 1
59.6%at or above 4 pCi/L
Median 4.4 pCi/L · 52 tests
- Radon levels in Spink CountyEPA zone 1
58.8%at or above 4 pCi/L
Median 4.9 pCi/L · 17 tests
- Radon levels in Potter CountyEPA zone 1
0.0%at or above 4 pCi/L
Median 1.2 pCi/L · 1 test
Faulk County, Cities and towns
Cities and towns in Faulk County
The Census Bureau estimates 2,178 residents in Faulk County for July 1, 2025, 50 more than in 2020 (+2.3%). Spread over its land, that is 2.2 people to the square mile. Its largest town, Faulkton, has 827 residents, 38.0% of the total. Together its 7 incorporated places hold 48.8% of those residents; the other 51.2% live outside any of them. Reported testing is thin here: 1 test over 2008 to 2017, or 0.5 for every 1,000 residents (2025 estimate), where South Dakota as a whole comes to 6.7.
From Faulkton to Onaka, CDC publishes no figure by town: each reads Faulk County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Faulkton | 827 | +0.1% | 38.0% |
| Cresbard | 104 | +4.0% | 4.8% |
| Orient | 54 | +5.9% | 2.5% |
| Seneca | 24 | +4.3% | 1.1% |
| Rockham | 20 | +5.3% | 0.9% |
| Chelsea | 19 | Level | 0.9% |
| Onaka | 14 | +7.7% | 0.6% |
7 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).
Faulk County, Homes
Homes in Faulk County
Faulk County is a place of houses on their own lots: 84% of its 1,080 homes are detached single-family houses, against 67% across South Dakota. The homes are older than South Dakota's as a whole: half were built before 1960 (1979 for South Dakota), and 50% date from before 1960. Owners live in 82% of the occupied homes (South Dakota: 69%), so for most households a test and a fix are their own to order.
| Homes | Faulk County | South Dakota |
|---|---|---|
| Housing units | 1,080 | 402,364 |
| Detached houses | 84% | 67% |
| In buildings of 5 or more | 6% | 16% |
| Mobile homes | 8% | 8% |
| Built before 1960 | 50% | 29% |
| Built since 2000 | 13% | 28% |
| Middle year built | 1960 | 1979 |
| Owner-occupied | 82% | 69% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.