Short-term kit
Radon Short Term Test Kit short-term charcoal radon test kit, lab fee included
- Lab fee included
Method: Charcoal
In home: 2 to 7 days
Locations and reports
Radon Levels in Colleton County, South Carolina
EPA puts Colleton County in Zone 3, its lowest radon zone, and only 11 radon tests from it are 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
5.7%
Orangeburg County
- Orangeburg
- 5.7%
- Charleston
- 1.5%
4 of 7 neighbours have 30+ tests, 2008 to 2017
Nearest county
4.8%
Dorchester County, 21 miles
- Dorchester
- 4.8%
- SC
- 19.4%
Share at 4+ pCi/L, 104 tests, 2008 to 2017
Ground above low
None
18.5 pts below SC
- Colleton
- 0.0%
- SC
- 18.5%
Share of land USGS rates moderate or high potential
Tests reported
11
Too few for a share
- Colleton
- 11
- Needed
- 30
2008 to 2017, laboratory
EPA radon zone
Zone 3
Lower potential
- 1
- 2
- Zone 3
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Read a result for Colleton 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
Colleton County, At a glance
Colleton County at a glance
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
USGS geologic potential: Low across 99% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Colleton County, 2008 to 2017, laboratory
CDC holds 11 reported tests for Colleton County over the 2008 to 2017 laboratory totals, with a median of 0.1 pCi/L: too few to describe a county (Radon411 reads a share from 30 tests up). Colleton County beside the counties around it is how this page reads it.
What these figures count
Only 11 tests were reported to CDC for Colleton 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).
Colleton County, Compared
Colleton County radon figures, compared
Calculated by Radon411CDC's largest figure for Colleton County rests on 11 tests over the 2008 to 2017 laboratory totals, 1 of them at or above 4 pCi/L, so each test moves its share by 9.1 points and no rank or comparison is drawn from it. Results reached as high as 4.4 pCi/L, with a middle value of 0.1 pCi/L.
Of the counties bordering it, 4 have a figure over the 2008 to 2017 laboratory totals: Orangeburg County reported the largest share at or above 4 pCi/L, 5.7%, and Charleston County the smallest, 1.5%, with Dorchester County at 4.8% and Beaufort County at 2.0% between. Farther out, Berkeley County (47 miles away) at 4.0%, Aiken County (73 miles away) at 13.3% and Sumter County (74 miles away) at 11.9% have figures too. Pooled across 46 South Carolina counties, 19.4% of reported tests reached that level; across every county in the country with a figure, 35.7%.
Statewide for the same period, Oconee County reported the highest share (42.6%) and Florence County the lowest (0.0%). EPA's 1993 map puts Colleton County in Zone 3, its lowest label: a predicted county average under 2 pCi/L. USGS geology rates 99% of the county's land low radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Colleton County, Geology
The ground under Colleton County
PredictedUSGS's geologic map puts all of Colleton County's mapped land in one class: low radon potential. 96.8% of it lies in the area the map calls Lower Coastal Plain, to which USGS gives a radon index of 7, in the low band (5 to 8).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Lower Coastal Plain | Dune, beach, and marine sediments. | Low | 7 | 96.8% |
| Upper and Middle Coastal Plain | Tertiary coastal plain sandy and silty sediments and marsh deposits. | Low | 8 | 2.2% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Colleton County beside the ground around it
Across South Carolina 0.2% of the land is rated high; none of Colleton County's is. None of the 7 counties that border it has any moderate-potential ground either.
The map rates the ground, not the air in any home.
Local help
Colleton County, Local resources
Radon testing and mitigation in Colleton County
- South Carolina Radon ProgramSouth Carolina Radon Program, run by South Carolina Department of Environmental Services, offers free or discounted test kits, and answers questions about testing and mitigation in South Carolina.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsThe program says:
The South Carolina Radon Program offers free short-term radon test kits to South Carolina homeowners, subject to availability.
- Compare kits
- Professionals in South Carolina2 professionals are listed in South Carolina.
What South Carolina's program says
- Phone
- 1-800-768-0362
- radon@des.sc.gov
What it means
Colleton County, Questions
Questions about radon in Colleton County
Are radon levels high in Colleton County?
Over the 2008 to 2017 laboratory totals, 9.1% of the radon tests reported to CDC for Colleton County, South Carolina were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.1 pCi/L. Of the counties bordering it, 4 have a figure over the 2008 to 2017 laboratory totals: Orangeburg County reported the largest share at or above 4 pCi/L, 5.7%, and Charleston County the smallest, 1.5%, with Dorchester County at 4.8% and Beaufort County at 2.0% between.
Which counties border Colleton County?
Colleton County borders 7 counties: Dorchester County, Hampton County, Beaufort County, Charleston County, Bamberg County, Allendale County and Orangeburg County.
Products
Colleton County, Products
Testing a home in Colleton County
No CDC figure names Colleton County; the nearest county with one, Dorchester County (21 miles away), reported 4.8% of its tests at or above 4 pCi/L over the 2008 to 2017 laboratory totals, the only reading nearby until a test of this home. Zone 3 is the lowest label, yet homes at or above 4 pCi/L occur in every zone: a short-term kit (2 to 90 days) is the quick first check in Colleton County.
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
Monitor
EcoBlu plug-in digital radon monitor with a display
- C-NRPP 2024/25: Not included
- Plug-in
- Alarm
- Screen
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
Colleton County, Bordering counties
Counties bordering Colleton County
Calculated by Radon411- Radon levels in Orangeburg CountyEPA zone 3
5.7%at or above 4 pCi/L
Median 0.9 pCi/L · 53 tests
- Radon levels in Bamberg CountyEPA zone 3
5.0%at or above 4 pCi/L
Median 1.0 pCi/L · 20 tests
- Radon levels in Dorchester CountyEPA zone 3
4.8%at or above 4 pCi/L
Median 1.0 pCi/L · 104 tests
- Radon levels in Beaufort CountyEPA zone 3
2.0%at or above 4 pCi/L
Median 0.7 pCi/L · 246 tests
- Radon levels in Charleston CountyEPA zone 3
1.5%at or above 4 pCi/L
Median 0.6 pCi/L · 272 tests
- Radon levels in Hampton CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 6 tests
- Radon levels in Allendale CountyEPA zone 3
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 1 test
Colleton County, Cities and towns
Cities and towns in Colleton County
The Census Bureau estimates 39,382 residents in Colleton County for July 1, 2025, 844 more than in 2020 (+2.2%). That works out to 37 people per square mile of land. No town dominates: Walterboro, the largest, has 5,485 residents, 13.9% of the total. Together its 6 incorporated places hold 19.2% of those residents; the other 80.8% live outside any of them. Reported testing is thin here: 11 tests over 2008 to 2017, or 0.3 for every 1,000 residents (2025 estimate), where South Carolina as a whole comes to 4.8.
From Walterboro to Lodge, CDC publishes no figure by town: each reads Colleton County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Walterboro | 5,485 | −0.2% | 13.9% |
| Edisto Beach | 1,071 | +4.1% | 2.7% |
| Cottageville | 735 | +3.5% | 1.9% |
| Smoaks | 97 | −1.0% | 0.2% |
| Williams | 95 | −1.0% | 0.2% |
| Lodge | 85 | Level | 0.2% |
6 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).
Colleton County, Homes
Homes in Colleton County
Mobile homes are 38% of Colleton County's 19,994 homes and detached houses 54%, against 64% across South Carolina. Half of its homes were built before 1988, close to South Carolina's 1991: 12% date from before 1960 and 24% from 2000 or later. 73% of occupied homes are lived in by their owner (South Carolina: 71%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Colleton County | South Carolina |
|---|---|---|
| Housing units | 19,994 | 2,401,638 |
| Detached houses | 54% | 64% |
| In buildings of 5 or more | 4% | 13% |
| Mobile homes | 38% | 15% |
| Built before 1960 | 12% | 13% |
| Built since 2000 | 24% | 35% |
| Middle year built | 1988 | 1991 |
| Owner-occupied | 73% | 71% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.