Radon in Union County, South Carolina
Last updated
Union County is one of 37 South Carolina counties (out of 46) that EPA places in Zone 3. 9 ZIP codes reach into the county, 4 of them entirely.
What the zone means for a Union County home
Zone 3 means EPA predicted a county-wide average below 2 pCi/L. Many Union County homes will test low, but EPA has found homes above the action level in every Zone 3 county it studied, so a low zone is not a pass.
A short-term test kit costs little and takes two to seven days. If your result is 4 pCi/L or higher, EPA recommends a follow-up test and, if it is confirmed, a mitigation system, which typically uses a pipe and fan to pull soil gas from under the foundation and vent it above the roof. Check a result with the level calculator and plan your next step with the follow-up planner.
Finding a radon professional in Union County
We have not added South Carolina professionals yet. Until we do, use the South Carolina radon program (SC Department of Environmental Services, 800-768-0362) at des.sc.gov/programs/bureau-air-quality/air-pollution/radon, or the national certification boards: the NRPP pro search and NRSB find a pro. Or ask for free quotes below.
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Tell us what you need and we will try to connect you with up to three state-certified or licensed radon professionals who work in your area. It is free and there is no obligation.
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ZIP codes in Union County
Open a ZIP to see every county it touches. Where a ZIP crosses a county line, the percentage is the share of its land area inside Union County.
South Carolina radon program
EPA lists SC Department of Environmental Services (phone 800-768-0362) as the state contact. State programs can tell you about local test results, discounted kits, disclosure rules for home sales and credentialed professionals. Website: des.sc.gov/programs/bureau-air-quality/air-pollution/radon.
Back to all South Carolina counties.
Frequently asked questions
What is the EPA radon zone for Union County, South Carolina?
EPA's Map of Radon Zones puts Union County in Zone 3 (low potential): Predicted average indoor screening level below 2 pCi/L.
Do I need to test for radon in Union County if the zone is low?
Yes. EPA says the zone map should not be used to decide whether a single home needs testing. Homes with high radon are found in every zone, and neighboring homes can test very differently. Testing is cheap and the only way to know your level.
How do I find a certified radon professional in Union County?
Ask the South Carolina radon program (SC Department of Environmental Services, 800-768-0362) for its list of credentialed professionals, or search the national certification boards, NRPP and NRSB. You can also ask for free quotes with the form on this page.
How many ZIP codes are in Union County?
9 ZIP codes have at least part of their land area in Union County, based on the U.S. Census Bureau's 2020 ZIP Code Tabulation Area to county relationship file.
Free checklist · PDF
Radon Test Checklist
A one-page, step-by-step checklist for running a home radon test right the first time, and what to do with the number.
- Short-term vs. long-term test: which to use
- Closed-house conditions and where to place the kit
- What 2, 4 and 8 pCi/L mean and when to fix
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