Short-term kit
RA100 short-term liquid scintillation radon test kit
- Lab fee extra
Method: Liquid scintillation
In home: 48 to 96 hours
Locations and reports
Radon Levels in Sumner County, Tennessee
EPA puts Sumner County in Zone 2, its middle radon zone, and 20.0% of its 30 reported radon tests (2023) 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
20.0%
4.9 pts below TN
- Sumner
- 20.0%
- Tennessee
- 24.9%
30 tests, 2023
Median result
1.4pCi/L
Below action level
- Sumner
- 1.4 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2023
Tests reported
30
15th of 15 by tests
- Sumner
- 30
- Hamblen
- 594
Reported to CDC before any fix, 2023
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 Tennessee
7 of 15
Middle half
- Sumner
- 20.0%
- Blount
- 50.0%
By share, of 15 with 30+ tests
Read a result for Sumner County
Starts at Sumner County's median, 1.4 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.4 pCi/L
Below 2 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is below 2 pCi/L, the level at which EPA says a fix should be considered. Sumner County's median reported result, 2023.
The data
Sumner County, At a glance
Sumner County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Sumner County is a
USGS geologic potential: High across 80% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Sumner County, 2023
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2022 | 11.8% |
| 2023 | 20.0% |
2023: 20.0%. Across these years the share ran from 11.8% to 20.0%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
These are the 30 tests reported to CDC for Sumner County over 2023, 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: 2023. Measured data period: 2005 to 2023 (every CDC figure on file).
Sumner County, Compared
Sumner County radon figures, compared
Calculated by Radon411Sumner County's 30 reported tests in 2023 had a middle value of 1.4 pCi/L and a maximum of 9.7 pCi/L, and 20.0% reached 4 pCi/L. Tennessee as a whole (70 Tennessee counties, pooled) comes to 24.9%: 4.9 points higher than here.
Among its state's counties it ranks 7th of 15 Tennessee counties with 30 or more tests for the same period. Statewide for the same period, Blount County reported the highest share (50.0%) and Hamilton County the lowest (2.4%).
Below the action level, 18 tests (60.0%) came in under 2 pCi/L, against 49.4% statewide, and 6 tests (20.0%) fell between 2 and 4, against 25.7% statewide. The busiest year on file was 2022, with 153 tests reported; the quietest, 2023, had 30.
EPA's 1993 zone map puts Sumner County in Zone 2, a predicted county average between 2 and 4 pCi/L. USGS geology rates 80% of the county's land high radon potential.
Next door, the shares run from 2.4% in Wilson County to 27.4% in Davidson County, with Wilson County below Sumner County.
CDC also counts 11 tests taken after mitigation in Sumner County for the same period: tests in homes where a fix was already in.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Sumner County, Geology
The ground under Sumner County
PredictedMost of the ground under Sumner County is one class on USGS's geologic map: 79.6% of its land is high radon potential, with 20.4% moderate. The map puts 51.6% of Sumner County in the area it calls Nashville Basin and 28.0% in Cherty Highland, with one smaller area beside them. USGS gives the first a radon index of 14 and the second 12, both in the high band (12 to 17).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Nashville Basin | Mississippian Limestone. | High | 14 | 51.6% |
| Cherty Highland | Cherty dolostone. | High | 12 | 28.0% |
| Highland Rim | Paleozoic sedimentary rocks (limestone, shale, chert, and dolostone). | Moderate | 11 | 20.4% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Sumner County beside the ground around it
Sumner County has more high-potential ground than Tennessee as a whole: 79.6% of its land against 47.2%. Of the 7 counties that border it, 4 have more high-potential ground, Macon County the most at 100%.
The map rates the ground, not the air in any home.
Local help
Sumner County, Local resources
Radon testing and mitigation in Sumner County
- Tennessee Radon ProgramTennessee Radon Program, run by Department of Environment & Conservation, offers free or discounted test kits, and answers questions about testing and mitigation in Tennessee.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
The Tennessee Radon Program provides free radon test kits and information assistance to residents, while also providing training opportunities to radon professionals across the state.
- Compare kits
- Professionals in Tennessee1 professional is listed in Tennessee.
What Tennessee's program says
- Phone
- 1-800-232-1139
- TDEC.Radon@tn.gov
What it means
Sumner County, Questions
Questions about radon in Sumner County
Are radon levels high in Sumner County?
In 2023, 20.0% of the radon tests reported to CDC for Sumner County, Tennessee were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.4 pCi/L. Of 15 Tennessee counties with 30 or more tests for the same period, 6 reported a higher share; pooled, the state comes to 24.9%.
Which counties border Sumner County?
Sumner County borders 7 counties: Trousdale County, TN, Wilson County, TN, Simpson County, KY, Robertson County, TN, Davidson County, TN, Macon County, TN and Allen County, KY.
Products
Sumner County, Products
Testing a home in Sumner County
In Sumner County, 20.0% of 30 tests reported to CDC in 2023 reached 4 pCi/L, against 24.9% pooled across Tennessee. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Sumner 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-3699 radon monitor with a 2.1-inch touchscreen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
First reading: Within 1 hour
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Sumner County, Bordering counties
Counties bordering Sumner County
Calculated by Radon411- Radon levels in Macon County, TNEPA zone 1
100.0%at or above 4 pCi/L
Median 4.1 pCi/L · 1 test · 80.0 points above Sumner County
- Radon levels in Davidson County, TNEPA zone 1
27.4%at or above 4 pCi/L
Median 2.2 pCi/L · 146 tests · 7.4 points above Sumner County
- Radon levels in Robertson County, TNEPA zone 2
7.1%at or above 4 pCi/L
Median 0.8 pCi/L · 14 tests · 12.9 points below Sumner County
- Radon levels in Wilson County, TNEPA zone 1
2.4%at or above 4 pCi/L
Median 0.9 pCi/L · 82 tests · 17.6 points below Sumner County
- Radon levels in Trousdale County, TNEPA zone 1
0.0%at or above 4 pCi/L
Median 3.6 pCi/L · 1 test · 20.0 points below Sumner County
- Radon levels in Simpson County, KYEPA zone 2
No CDC figure for 2023; its page reads it against its own neighbours.
- Radon levels in Allen County, KYEPA zone 1
No CDC figure for 2023; its page reads it against its own neighbours.
Sumner County, Cities and towns
Cities and towns in Sumner County
Sumner County is growing: the Census Bureau puts it at 215,538 residents on July 1, 2025, up 9.2% from 197,416 in 2020. That works out to 407 people per square mile of land. Its largest town, Hendersonville, has 64,266 residents, 29.8% of the total. Reported testing is thin here: 30 tests over 2023, or 0.1 for every 1,000 residents (2025 estimate), where Tennessee as a whole comes to 0.3.
From Hendersonville to Mitchellville, CDC publishes no figure by town: each reads Sumner County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Hendersonville | 64,266 | +3.5% | 29.8% |
| Gallatin | 54,590 | +21.7% | 25.3% |
| White Houseextends beyond Sumner County | 17,872 | +36.6% | Counted whole |
| Goodlettsvilleextends beyond Sumner County | 17,506 | −1.6% | Counted whole |
| Portlandextends beyond Sumner County | 13,658 | +3.5% | Counted whole |
| Millersvilleextends beyond Sumner County | 6,438 | +2.0% | Counted whole |
| Westmoreland | 2,879 | +2.9% | 1.3% |
| Mitchellville | 221 | +37.3% | 0.1% |
8 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 Sumner County is counted whole, so it has no share.
Sumner County, Homes
Homes in Sumner County
Of Sumner County's 81,376 homes, 73% are detached houses, against 68% across Tennessee; 13% are in buildings of five or more homes. Much of Sumner County is recent building: 40% of its homes have gone up since 2000 and the middle year built is 1994, against 1986 for Tennessee. 72% of occupied homes are lived in by their owner (Tennessee: 67%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Sumner County | Tennessee |
|---|---|---|
| Housing units | 81,376 | 3,095,472 |
| Detached houses | 73% | 68% |
| In buildings of 5 or more | 13% | 14% |
| Mobile homes | 6% | 8% |
| Built before 1960 | 7% | 18% |
| Built since 2000 | 40% | 29% |
| Middle year built | 1994 | 1986 |
| Owner-occupied | 72% | 67% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.