Short-term kitempowerDX
Standard Radon Test short-term mail-in radon test kit
- Lab fee included
Method: Passive sampler
In home: 48 to 96 hours
Locations and reports
Radon Levels in Clay County, North Carolina
EPA puts Clay County in Zone 2, its middle radon zone, and only 23 radon tests from it are on file with CDC (2021). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Share at 4+ pCi/L
43.0%
20.4 pts above NC
- Clay
- 43.0%
- NC
- 22.6%
323 tests, 2008 to 2017
Median result
3.0pCi/L
Below action level
- Clay
- 3.0 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
323
40th of 75 by tests
- Clay
- 323
- Wake
- 9,694
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 NC
6 of 75
Top quarter
- Clay
- 43.0%
- Transylvania
- 47.8%
By share, of 75 with 30+ tests
Read a result for Clay County
Starts at Clay County's median, 3.0 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 3.0 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. Clay County's median reported result, 2008 to 2017.
The data
Clay County, At a glance
Clay County at a glance
Predicted: EPA radon zone
EPA Zone 2: moderate predicted potential
Clay 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 Clay County, 2021
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 38.1% |
| 2020 | 39.7% |
| 2021 | 26.1% |
2021: 26.1%. Across these years the share ran from 26.1% to 39.7%. Each column counts radon tests reported to CDC that year, not homes.
What these figures count
Only 23 tests were reported to CDC for Clay County over 2021, 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: 2021. Measured data period: 2005 to 2021 (every CDC figure on file).
Clay County, Compared
Clay County radon figures, compared
Calculated by Radon411In Clay County, about 4 in 10 reported tests over the 2008 to 2017 laboratory totals (139 of 323) were at or above EPA's action level. Against the national pool of 35.7%, the gap is 7.3 points higher. Across 99 North Carolina counties pooled together, 22.6% of tests reached that level, so Clay County runs 20.4 points above its state.
The newest figure, in 2021, counts only 23 tests (26.1% at or above 4 pCi/L), too few to compare, so this reading uses the 323-test figure.
Of 5 neighbours with a figure, 2 reported a larger share at or above 4 pCi/L and 3 a smaller one; the spread is 17.1% (Macon County) to 44.6% (Union County, GA). By share, Clay County is 6th of 75 North Carolina counties with 30 or more tests for the same period.
Half the tests came in under 3.0 pCi/L and half over it; the single highest reached 266.1 pCi/L. Below the action level, 106 tests (32.8%) came in under 2 pCi/L, against 55.6% statewide, and 78 tests (24.1%) fell between 2 and 4, against 21.8% statewide.
Zone 2 on EPA's map (predicted average between 2 and 4 pCi/L) and a 43.0% share point the same way here. USGS geology rates 100% of the county's land moderate radon potential. CDC also counts 30 tests taken after mitigation in Clay County for the same period: tests in homes where a fix was already in.
The busiest year on file was 2020, with 58 tests reported; the quietest, 2021, had 23.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Clay County, Geology
The ground under Clay County
PredictedUSGS's geologic map puts all of Clay County's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Blue Ridge, to which USGS gives a radon index of 10, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Blue Ridge | Granite, pegmatite, monazite, schist, and gneiss. | Moderate | 10 | 99.7% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Clay County beside the ground around it
Across North Carolina 1.3% of the land is rated high; none of Clay County's is. Of the 5 counties that border it, none has as large a share of moderate-potential ground; Cherokee County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Clay County, Local resources
Radon testing and mitigation in Clay County
- North Carolina Radon ProgramNorth Carolina Radon Program, run by NCDHHS, answers questions about testing, mitigation and the rules in North Carolina.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 North Carolina2 professionals are listed in North Carolina.
What North Carolina's program says
- Licensing of radon professionals
The North Carolina Radon Program is presently developing a Radon Proficiency Program as directed by Session Law 2023-91 House Bill 782 .
What it means
Clay County, Questions
Questions about radon in Clay County
Are radon levels high in Clay County?
In 2021, 26.1% of the radon tests reported to CDC for Clay County, North Carolina were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.0 pCi/L. Of 75 North Carolina counties with 30 or more tests for the same period, 5 reported a higher share; pooled, the state comes to 22.6%.
Which counties border Clay County?
Clay County borders 5 counties: Towns County, GA, Macon County, NC, Cherokee County, NC, Union County, GA and Rabun County, GA.
Products
Clay County, Products
Testing a home in Clay County
In Clay County, 43.0% of 323 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 22.6% pooled across North Carolina. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Clay County; a long-term test tells the year-round average.
Test kits and monitors3
See every kit and monitor
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
Monitor
EcoQube Wi-Fi continuous radon monitor
- C-NRPP 2024/25: Approved
- Plug-in
- Wi-Fi
- App only
Method: Ion chamber
First reading: Within 10 minutes
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Clay County, Bordering counties
Counties bordering Clay County
Calculated by Radon411- Radon levels in Union County, GAEPA zone 2
44.6%at or above 4 pCi/L
Median 3.3 pCi/L · 276 tests · 1.6 points above Clay County
- Radon levels in Cherokee County, NCEPA zone 1
43.2%at or above 4 pCi/L
Median 3.4 pCi/L · 1,045 tests · 0.2 points above Clay County
- Radon levels in Towns County, GAEPA zone 2
31.9%at or above 4 pCi/L
Median 2.8 pCi/L · 144 tests · 11.1 points below Clay County
- Radon levels in Rabun County, GAEPA zone 2
26.1%at or above 4 pCi/L
Median 2.0 pCi/L · 69 tests · 16.9 points below Clay County
- Radon levels in Macon County, NCEPA zone 2
17.1%at or above 4 pCi/L
Median 1.4 pCi/L · 1,354 tests · 25.9 points below Clay County
Clay County, Cities and towns
Cities and towns in Clay County
Clay County is growing: the Census Bureau puts it at 12,239 residents on July 1, 2025, up 9.9% from 11,141 in 2020. That works out to 57 people per square mile of land. Hayesville, its one incorporated place, has 470 residents, 3.8% of the total. Testing is reported here more often than across the state: CDC's 323 reported tests for 2008 to 2017 come to 26.4 for every 1,000 residents (2025 estimate), against 6.5 for North Carolina.
Hayesville is the one incorporated place here; CDC publishes no figure by town, so it reads Clay County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Hayesville | 470 | +7.6% | 3.8% |
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).
Clay County, Homes
Homes in Clay County
Clay County is a place of houses on their own lots: 81% of its 7,410 homes are detached single-family houses, against 65% across North Carolina. Half of its homes were built before 1989, close to North Carolina's 1990: 12% date from before 1960 and 30% from 2000 or later. Owners live in 80% of the occupied homes (North Carolina: 66%), so for most households a test and a fix are their own to order.
| Homes | Clay County | North Carolina |
|---|---|---|
| Housing units | 7,410 | 4,815,195 |
| Detached houses | 81% | 65% |
| In buildings of 5 or more | 4% | 14% |
| Mobile homes | 12% | 11% |
| Built before 1960 | 12% | 14% |
| Built since 2000 | 30% | 33% |
| Middle year built | 1989 | 1990 |
| Owner-occupied | 80% | 66% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.