Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 days
Locations and reports
Radon Levels in Spencer County, Kentucky
EPA puts Spencer County in Zone 2, its middle radon zone, and 31.3% of its 166 reported radon tests (2008 to 2017, laboratory totals) were 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
31.3%
12.4 pts below KY
- Spencer
- 31.3%
- Kentucky
- 43.7%
166 tests, 2008 to 2017
Median result
2.5pCi/L
Below action level
- Spencer
- 2.5 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
166
26th of 69 by tests
- Spencer
- 166
- Jefferson
- 6,590
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 2
Moderate potential
- 1
- Zone 2
- 3
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Rank in Kentucky
44 of 69
Middle half
- Spencer
- 31.3%
- Meade
- 68.4%
By share, of 69 with 30+ tests
Read a result for Spencer County
Starts at Spencer County's median, 2.5 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 2.5 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. Spencer County's median reported result, 2008 to 2017.
The data
Spencer County, At a glance
Spencer County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Spencer County is a
USGS geologic potential: Moderate across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Spencer County, 2008 to 2017, laboratory
Under 2 pCi/L: 42%2 to 4 pCi/L: 27%4 pCi/L and above: 31%
Of 166 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 70 | 42.2% |
| 2 to 4 pCi/L | 44 | 26.5% |
| 4 pCi/L and above | 52 | 31.3% |
What these figures count
These are the 166 tests reported to CDC for Spencer 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).
Spencer County, Compared
Spencer County radon figures, compared
Calculated by Radon411In Spencer County, about 3 in 10 reported tests over the 2008 to 2017 laboratory totals (52 of 166) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 4.4 points lower. Across 120 Kentucky counties pooled together, 43.7% of tests reached that level, so Spencer County runs 12.4 points below its state.
Of 5 neighbours with a figure, 4 reported a larger share at or above 4 pCi/L and 1 a smaller one; the spread is 25.2% (Anderson County) to 66.1% (Nelson County). By share, Spencer County is 44th of 69 Kentucky counties with 30 or more tests for the same period.
Half the tests came in under 2.5 pCi/L and half over it; the single highest reached 46.0 pCi/L. Below the action level, 70 tests (42.2%) came in under 2 pCi/L, against 33.2% statewide, and 44 tests (26.5%) fell between 2 and 4, against 23.1% statewide.
Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 31.3% share point the same way here. USGS geology rates 100% of the county's land moderate radon potential. CDC also counts 5 tests taken after mitigation in Spencer County for the same period: tests in homes where a fix was already in.
CDC's ten-year totals for Spencer County went from 102 tests (2005 to 2014) to 166 (2008 to 2017), the share going from 33.3% to 31.3%.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Spencer County, Geology
The ground under Spencer County
PredictedUSGS's geologic map puts all of Spencer County's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Outer Bluegrass, to which USGS gives a radon index of 11, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Outer Bluegrass | Ordovician-Devonian limestone and shale. | Moderate | 11 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Spencer County beside the ground around it
Across Kentucky 18.2% of the land is rated high; none of Spencer County's is. Of the 5 counties that border it, 4 have more high-potential ground, Bullitt County the most at 73.4%.
The map rates the ground, not the air in any home.
Local help
Spencer County, Local resources
Radon testing and mitigation in Spencer County
- Kentucky's radon programKentucky Board of Radon SafetyKentucky's radon program answers questions about testing, mitigation and the rules in Kentucky.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 Kentucky8 professionals are listed in Kentucky.
What Kentucky's program says
- Phone
- 502-782-2782
- Radon@ky.gov
What it means
Spencer County, Questions
Questions about radon in Spencer County
Are radon levels high in Spencer County?
Over the 2008 to 2017 laboratory totals, 31.3% of the radon tests reported to CDC for Spencer County, Kentucky were at or above 4 pCi/L, and the median reported pre-mitigation result was 2.5 pCi/L. Of 69 Kentucky counties with 30 or more tests for the same period, 43 reported a higher share; pooled, the state comes to 43.7%.
Which counties border Spencer County?
Spencer County borders 5 counties: Shelby County, Anderson County, Jefferson County, Bullitt County and Nelson County.
Products
Spencer County, Products
Testing a home in Spencer County
In Spencer County, 31.3% of 166 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 43.7% pooled across Kentucky. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Spencer County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
MonitorAEGTEST
HOUND-1011S rechargeable radon detector with a screen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
First reading: Within 12 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Spencer County, Bordering counties
Counties bordering Spencer County
Calculated by Radon411- Radon levels in Nelson CountyEPA zone 1
66.1%at or above 4 pCi/L
Median 6.3 pCi/L · 304 tests · 34.8 points above Spencer County
- Radon levels in Bullitt CountyEPA zone 1
47.5%at or above 4 pCi/L
Median 3.6 pCi/L · 551 tests · 16.2 points above Spencer County
- Radon levels in Jefferson CountyEPA zone 1
39.4%at or above 4 pCi/L
Median 2.7 pCi/L · 6,590 tests · 8.1 points above Spencer County
- Radon levels in Shelby CountyEPA zone 2
37.6%at or above 4 pCi/L
Median 3.0 pCi/L · 407 tests · 6.3 points above Spencer County
- Radon levels in Anderson CountyEPA zone 2
25.2%at or above 4 pCi/L
Median 2.2 pCi/L · 226 tests · 6.1 points below Spencer County
Spencer County, Cities and towns
Cities and towns in Spencer County
Spencer County is growing: the Census Bureau puts it at 20,998 residents on July 1, 2025, up 7.7% from 19,496 in 2020. That works out to 112 people per square mile of land. Taylorsville, its one incorporated place, has 1,333 residents, 6.3% of the total. CDC's 166 reported tests for 2008 to 2017 work out to 7.9 per 1,000 residents (2025 estimate), close to Kentucky's 6.3.
Taylorsville is the one incorporated place here; CDC publishes no figure by town, so it reads Spencer County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Taylorsville | 1,333 | +6.1% | 6.3% |
One incorporated place, 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).
Spencer County, Homes
Homes in Spencer County
Spencer County is a place of houses on their own lots: 90% of its 7,599 homes are detached single-family houses, against 68% across Kentucky. Much of Spencer County is recent building: 45% of its homes have gone up since 2000 and the middle year built is 1998, against 1982 for Kentucky. Owners live in 87% of the occupied homes (Kentucky: 68%), so for most households a test and a fix are their own to order.
| Homes | Spencer County | Kentucky |
|---|---|---|
| Housing units | 7,599 | 2,010,655 |
| Detached houses | 90% | 68% |
| In buildings of 5 or more | 3% | 12% |
| Mobile homes | 6% | 11% |
| Built before 1960 | 10% | 22% |
| Built since 2000 | 45% | 24% |
| Middle year built | 1998 | 1982 |
| Owner-occupied | 87% | 68% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.