Locations and reports
Radon Levels in Horry County, South Carolina
What this means for you
- Your area: EPA rates Horry County Zone 3, the lowest of its three radon zones. That is a prediction for the whole county, and homes with elevated levels occur in all three zones.
- Local tests: Of 106 radon tests reported to CDC for Horry County (2008 to 2017), 0.9% were at or above 4 pCi/L, EPA's action level.
- Your home: The only way to know your home’s level is to test it.
pCi/L (picocuries per liter) is the unit radon is measured in. EPA recommends fixing a home at 4 pCi/L or above, its action level.
Over the 2008 to 2017 laboratory totals, 0.9% of the radon tests reported to CDC for Horry County, South Carolina came back at or above the EPA action level of 4 pCi/L, and the median result was 0.6 pCi/L. EPA's Map of Radon Zones places the county in Zone 3, lower predicted potential. Radon levels vary from home to home, so only a test measures the level in yours.
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
EPA predicts an average indoor of less than 2 pCi/L (less than 75 Bq/m³) across the county as a whole.
This is a county-level geologic prediction. It is not a measurement of any address, and houses with elevated radon are found in all three zones.
USGS geologic potential: High across 99% of the county's land area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
Radon tests reported for Horry County, 2008 to 2017, laboratory
- Tests reported
- 106
- At or above 4 pCi/L
- 0.9%
- Median result
- 0.6 pCi/L
Of 106 pre-mitigation tests reported to CDC, not homes in this area. CDC publishes the share in each band, not a count per band, so the per-band counts in the table are calculated by Radon411 and rounded to add up to the published total.
| Result band | Tests Calculated by Radon411 | Share Measured |
|---|---|---|
| Under 2 pCi/L | 104 | 98.1% |
| 2 to 4 pCi/L | 1 | 0.9% |
| 4 pCi/L and above | 1 | 0.9% |
Distribution of tested buildings, not this house. People testing before a sale, or because they suspect a problem, are over-represented in any reported testing data.
Measured: CDC tracking data. Figure above: 2008 to 2017, laboratory. Measured data period: 2005 to 2017 (every CDC figure on file).
Horry County, In figures
Horry County in figures
What the published data says about Horry County, in words. A zone and a share of tests describe an area, never the level in any one home.
Predicted
PredictedEPA places Horry County in Zone 3, lower predicted potential, as it does 36 other counties of South Carolina's 46.
Of the 6 bordering counties, EPA places Brunswick County, Columbus County, Dillon County, Georgetown County, Marion County and Robeson County in Zone 3.
Reported tests
MeasuredCDC publishes no annual figure for Horry County; its figure is a laboratory total for 2008 to 2017: 0.9% of 106 reported tests were at or above 4 pCi/L.
Local record
South Carolina's radon program is the South Carolina Radon Program, run by South Carolina Department of Environmental Services; its contacts are under Local resources.
The county's largest incorporated places are Myrtle Beach, Conway and North Myrtle Beach; the figures here cover them as part of the county.
Horry County, Comparison
How Horry County compares
MeasuredHorry County's own published CDC figures beside those of the counties that border it, for the same period.
Share of reported tests at or above 4 pCi/L
Measured2008 to 2017, laboratory, highest first. Each county’s own published CDC figure.
- Robeson CountyNC53 tests3.8%
- Horry CountyThis page106 tests0.9%
- Brunswick CountyNC62 tests0.0%
- Columbus CountyNC31 tests0.0%
- Dillon CountySC18 tests0.0%
- Georgetown CountySC29 tests0.0%
- Marion CountySC9 tests0.0%
Median reported result
Measured2008 to 2017, laboratory, highest first. Each county’s own published CDC figure.
- Marion CountySC9 tests0.9 pCi/L
- Robeson CountyNC53 tests0.8 pCi/L
- Horry CountyThis page106 tests0.6 pCi/L
- Brunswick CountyNC62 tests0.5 pCi/L
- Dillon CountySC18 tests0.3 pCi/L
- Columbus CountyNC31 tests0.1 pCi/L
- Georgetown CountySC29 tests0.1 pCi/L
Each figure is that county’s own published CDC figure for 2008 to 2017, laboratory, counting radon tests reported to CDC, not homes. Horry County is this page. Nothing is averaged or combined across counties. The test count beside each county is CDC’s published number of pre-mitigation tests behind its figures. Figures from few tests can swing widely from year to year. Every South Carolina county’s own figure is in the South Carolina county table.
CDC publishes this figure only for counties here, so there is no state or national number to compare Horry County, South Carolina with.
Horry County, Bordering counties
Counties bordering Horry County
Calculated by Radon4116 counties share a boundary with Horry County, computed from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county’s report can be worth reading alongside this one.
Horry County, Local resources
Local resources in South Carolina
Who to ask in South Carolina: the state's radon program, test kits and professionals.
South Carolina Radon Program
South Carolina Department of Environmental Services
South Carolina’s radon program answers questions about testing, mitigation and the rules where you live.
- Phone
- 1-800-768-0362
- radon@des.sc.gov
Test kits
The program says: The South Carolina Radon Program offers free short-term radon test kits to South Carolina homeowners, subject to availability.
Radon professionals
7 professionals are listed in South Carolina.
Professionals in South CarolinaHorry County, Cities and towns
Cities and towns in Horry County
The radon figures on this page are for Horry County as a whole. They do not differ by city or town.
- Myrtle Beach
- Conway
- North Myrtle Beach
- Surfside Beach
- Loris
- Aynor
- Briarcliffe Acres
- Atlantic Beach
8 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files.
Horry County, Questions
Questions about radon in Horry County
Common questions8 questions, answered from the figures above
Are radon levels high in Horry County?
In 2017, 0.9% of the radon tests reported to CDC for Horry County, South Carolina were at or above 4 pCi/L, and the median reported pre-mitigation result was 0.6 pCi/L. That is a share of reported tests, not of homes. EPA places Horry County in Zone 3, lower predicted potential, a predicted average indoor screening level less than 2 pCi/L. Homes with elevated levels occur in all three zones, so the figures describe the area, not your house. Testing is the only way to know the radon level in a specific building.
How do I get a radon test in Horry County?
EPA says you can test your home yourself or hire a qualified radon test company, and that either approach takes only a small amount of time and effort. No certified tester listed on Radon411 names Horry County as a service area yet. The South Carolina radon program is the place to ask about certified testers and any test kit offer it runs.
How to test a homeTest kits comparedFree and low-cost kits by stateSouth Carolina radon program
Who does radon mitigation in Horry County?
No listed mitigator names Horry County as a service area yet; the South Carolina directory lists 7 companies. EPA recommends having a qualified contractor fix a home with a radon problem, because lowering high radon levels takes technical knowledge and special skills, and some states require the work to be done by a licensed or certified professional. Your state radon program is the place to check whether South Carolina requires one.
How radon mitigation worksWhat mitigation costsMitigators in South Carolina
What EPA radon zone is Horry County in?
EPA places Horry County, South Carolina in Zone 3, which EPA describes as lower predicted potential for the area. A zone is a prediction for the whole county and never determines whether a particular home should be tested. EPA recommends testing every home regardless of zone.
Should I test my home in Horry County?
Yes. Testing is the only way to know the radon level in a specific building. EPA recommends fixing a home when the radon level is 4 pCi/L or higher. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. How to test a home.
When is the best time of year to test?
EPA says short-term tests stay in the home from 2 to 90 days and that all radon tests should run a minimum of 48 hours; long-term tests stay more than 90 days. EPA's guides do not name a best season: they say radon levels tend to vary from day to day and season to season, so a long-term test is more likely than a short-term test to tell you the year-round average.
What does it cost to test?
EPA's Citizen's Guide calls testing easy and inexpensive, and EPA's Home Buyer's and Seller's Guide says passive short-term and long-term devices are generally inexpensive, while active devices may cost more. No national average price is published for this, so Radon411 does not give one. What testing costs.
Which counties border Horry County?
Horry County borders 6 counties, derived from Census county geometry. Radon potential follows geology rather than county lines, so a bordering county's report can be relevant.
What these figures mean if you own, buy, sell or rent
The reported-test figures on this page describe Horry County, South Carolina in 2017. They describe tests other people carried out in other buildings, and none of them measures yours.
- How to test a home
If you own your home
Test the lowest lived-in level; a short-term kit screens in days, a long-term kit reflects the year.
- Buying a house: radon guide
If you are buying
Ask for past results and any system's post-mitigation test, and test during the sale.
- Selling a house: radon guide
If you are selling
Testing before you list puts the timing in your hands; disclosure rules differ by state.
- Radon in rental homes
If you rent, or rent out a home
A tenant can test; a fix is the owner's to make, and duties differ by state.
How long a test has to run, under what conditions, and what EPA says a result means: the testing standard, in full.
Horry County, Products
Testing and mitigation products
Whatever the figures for Horry County show, only a test tells you about one home.
Testing
- Short-term test kitsPassive detectors exposed for a few days under closed-building conditions, then analyzed by a lab.
- Long-term test kitsDetectors exposed for more than 90 days, for a closer picture of the annual average.
- Continuous monitorsPowered devices that log radon on a repeating cycle, often used for transaction tests.
- Digital detectorsConsumer devices that display a running radon reading without a lab.
- Water radon testsKits for radon dissolved in well water, analyzed by a lab.
Mitigation
- Mitigation fansThe inline fan that keeps a soil depressurization system running, sized by the installer.
- System indicatorsU-tube manometers and fan alarms that show whether a mitigation system is still working.
- Sealing materialsCrack, joint and sump sealing used alongside a mitigation system, not instead of one.
Horry County / Next steps
What to do next
Learn
Know what radon is
What radon is, how it gets indoors, and why a county zone is not a reading for your home.
Learn about radonTest
Test the building you live in
Short-term or long-term, where the device goes, and closed-house conditions.
How to testFix
Bring a high level down
How a mitigation system works, and the retest that confirms it.
How mitigation worksFind a pro
Hire a certified professional
Measurement and mitigation professionals by state, with their certifications.
Find a professional
Informational. Follow EPA guidance. EPA says all radon tests should be taken for a minimum of 48 hours, with windows and doors closed from 12 hours before a short-term test.