Short-term kit
PicoCan short-term charcoal canister radon test
- Lab fee included
Method: Charcoal
In home: 48 to 96 hours
Locations and reports
Radon Levels in Dorchester County, South Carolina
EPA puts Dorchester County in Zone 3, its lowest radon zone, and most reported tests there come back low, though 4.8% of 104 (2008 to 2017, laboratory totals) reached 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
4.8%
14.6 pts below SC
- Dorchester
- 4.8%
- SC
- 19.4%
104 tests, 2008 to 2017
Median result
1.0pCi/L
Below action level
- Dorchester
- 1.0 pCi/L
- EPA
- 4.0 pCi/L
Midpoint of the tests, 2008 to 2017
Tests reported
104
17th of 24 by tests
- Dorchester
- 104
- Greenville
- 12,004
Reported to CDC before any fix, 2008 to 2017
EPA radon zone
Zone 3
Lower potential
- 1
- 2
- Zone 3
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Rank in SC
19 of 24
Lowest quarter
- Dorchester
- 4.8%
- Oconee
- 42.6%
By share, of 24 with 30+ tests
Read a result for Dorchester County
Starts at Dorchester County's median, 1.0 pCi/L
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 1.0 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. Dorchester County's median reported result, 2008 to 2017.
The data
Dorchester County, At a glance
Dorchester County at a glance
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
USGS geologic potential: Low across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Dorchester County, 2008 to 2017, laboratory
Under 2 pCi/L: 78%2 to 4 pCi/L: 17%4 pCi/L and above: 5%
Of 104 pre-mitigation tests reported to CDC, not homes in this area.
| Result band | Tests Measured | Share Measured |
|---|---|---|
| Under 2 pCi/L | 81 | 77.9% |
| 2 to 4 pCi/L | 18 | 17.3% |
| 4 pCi/L and above | 5 | 4.8% |
What these figures count
These are the 104 tests reported to CDC for Dorchester 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).
Dorchester County, Compared
Dorchester County radon figures, compared
Calculated by Radon411Only 5 of 104 radon tests reported for Dorchester County over the 2008 to 2017 laboratory totals reached 4 pCi/L (4.8%). The median result, 1.0 pCi/L, sits below 2, well under EPA's 4 pCi/L action level, and the top reported result was 12.3 pCi/L.
Across 46 South Carolina counties pooled together, 19.4% of tests reached that level, so Dorchester County runs 14.6 points below its state. Against the national pool of 35.7%, the gap is 30.9 points lower. Its place in the state: 19th of 24 South Carolina counties with 30 or more tests for the same period.
Zone 3 on EPA's map (predicted average under 2 pCi/L) and a 4.8% share point the same way here. Of 3 neighbours with a figure, 1 reported a larger share at or above 4 pCi/L and 2 a smaller one; the spread is 1.5% (Charleston County) to 5.7% (Orangeburg County).
Below the action level, 81 tests (77.9%) came in under 2 pCi/L, against 57.4% statewide, and 18 tests (17.3%) fell between 2 and 4, against 23.1% statewide. USGS geology rates 100% of the county's land low radon potential.
CDC's ten-year totals for Dorchester County went from 100 tests (2005 to 2014) to 104 (2008 to 2017), the share going from 2.0% to 4.8%.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Dorchester County, Geology
The ground under Dorchester County
PredictedUSGS's geologic map puts all of Dorchester County's mapped land in one class: low radon potential. The map puts 90.2% of Dorchester County in the area it calls Lower Coastal Plain and 9.8% in Upper and Middle Coastal Plain. USGS gives the first a radon index of 7 and the second 8, both 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 | 90.2% |
| Upper and Middle Coastal Plain | Tertiary coastal plain sandy and silty sediments and marsh deposits. | Low | 8 | 9.8% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Dorchester County beside the ground around it
Across South Carolina 0.2% of the land is rated high; none of Dorchester County's is. None of the 4 counties that border it has any moderate-potential ground either.
The map rates the ground, not the air in any home.
Local help
Dorchester County, Local resources
Radon testing and mitigation in Dorchester 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
Dorchester County, Questions
Questions about radon in Dorchester County
Are radon levels high in Dorchester County?
Over the 2008 to 2017 laboratory totals, 4.8% of the radon tests reported to CDC for Dorchester County, South Carolina were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.0 pCi/L. Of 24 South Carolina counties with 30 or more tests for the same period, 18 reported a higher share; pooled, the state comes to 19.4%.
Which counties border Dorchester County?
Dorchester County borders 4 counties: Colleton County, Charleston County, Berkeley County and Orangeburg County.
Products
Dorchester County, Products
Testing a home in Dorchester County
In Dorchester County, 4.8% of 104 tests reported to CDC over the 2008 to 2017 laboratory totals reached 4 pCi/L, against 19.4% pooled across South Carolina. 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 Dorchester County.
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
RM-65 rechargeable radon detector with a color screen and alarm
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
Method: Semiconductor sensor
First reading: Within 6 hours
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Dorchester County, Bordering counties
Counties bordering Dorchester County
Calculated by Radon411- Radon levels in Colleton CountyEPA zone 3
9.1%at or above 4 pCi/L
Median 0.1 pCi/L · 11 tests · 4.3 points above Dorchester County
- Radon levels in Orangeburg CountyEPA zone 3
5.7%at or above 4 pCi/L
Median 0.9 pCi/L · 53 tests · 0.9 points above Dorchester County
- Radon levels in Berkeley CountyEPA zone 3
4.0%at or above 4 pCi/L
Median 0.7 pCi/L · 99 tests · 0.8 points below Dorchester County
- Radon levels in Charleston CountyEPA zone 3
1.5%at or above 4 pCi/L
Median 0.6 pCi/L · 272 tests · 3.3 points below Dorchester County
Dorchester County, Cities and towns
Cities and towns in Dorchester County
Dorchester County is growing: the Census Bureau puts it at 178,397 residents on July 1, 2025, up 10.1% from 162,056 in 2020. That works out to 314 people per square mile of land. North Charleston, the largest place on its list (129,245 residents in all), extends beyond Dorchester County, so no share of the total is worked out for it. Reported testing is thin here: 104 tests over 2008 to 2017, or 0.6 for every 1,000 residents (2025 estimate), where South Carolina as a whole comes to 4.8.
From North Charleston to Reevesville, CDC publishes no figure by town: each reads Dorchester County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| North Charlestonextends beyond Dorchester County | 129,245 | +11.8% | Counted whole |
| Summervilleextends beyond Dorchester County | 53,177 | +4.4% | Counted whole |
| St. George | 1,868 | +1.9% | 1.0% |
| Lincolnvilleextends beyond Dorchester County | 1,241 | +7.4% | Counted whole |
| Ridgeville | 1,230 | −32.9% | 0.7% |
| Harleyville | 773 | +13.2% | 0.4% |
| Reevesville | 197 | −2.5% | 0.1% |
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). A place that extends beyond Dorchester County is counted whole, so it has no share.
Dorchester County, Homes
Homes in Dorchester County
Of Dorchester County's 66,435 homes, 67% are detached houses, against 64% across South Carolina; 12% are mobile homes. Much of Dorchester County is recent building: 48% of its homes have gone up since 2000 and the middle year built is 1999, against 1991 for South Carolina. Owners live in 75% of the occupied homes (South Carolina: 71%), so for most households a test and a fix are their own to order.
| Homes | Dorchester County | South Carolina |
|---|---|---|
| Housing units | 66,435 | 2,401,638 |
| Detached houses | 67% | 64% |
| In buildings of 5 or more | 11% | 13% |
| Mobile homes | 12% | 15% |
| Built before 1960 | 4% | 13% |
| Built since 2000 | 48% | 35% |
| Middle year built | 1999 | 1991 |
| Owner-occupied | 75% | 71% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.