Fluoride is widespread in Charleston County wells.
1 widespread, 5 rare out of 6 health checks.
From 18 wells tested in Charleston County since 2000; your own well needs its own test. How to read this
Not charted, because fewer than 10 wells were tested: radon (5).
Rare: under 5%Worth checking: 5 to 15%Widespread: 15%+
Lab results: Water Quality Portal (USGS and EPA)
Who drinks from a well here
About 1 in 15 people 26,768 people
Nobody else tests these wells. Only you do.
People on wells: EPA researchers' 2020 estimate
How deep wells go here
Deep wells: fewer surface germs, more minerals from the rock.
Well depths: US Groundwater Well Database
Radon risk (a gas from rock)
Less likely, but the EPA still says test your air.
Radon zones: EPA map
Here's how Charleston County compares with South Carolina and the counties around it.
Each result puts Charleston County next to the 4 counties that border it, on the chart's 0 to 50% scale.
This one is widespread in Charleston County wells.
Fluoride4 of 18 wells over
Too few tested to show: Dorchester, Georgetown.
These 5 are rare in Charleston County.
Nitrate0 of 18 wells over
Too few tested to show: Dorchester, Georgetown.
Lead0 of 10 wells over
Too few tested to show: Dorchester, Georgetown.
Arsenic0 of 10 wells over
Too few tested to show: Dorchester, Georgetown.
Manganese0 of 16 wells over
Too few tested to show: Dorchester, Georgetown.
Uranium0 of 10 wells over
Too few tested to show: Dorchester, Georgetown.
Too few Charleston County wells were tested for this one.
Radon in water5 wells tested
Coliform bacteria turned up in 3 of 7 tested Charleston County wells, so test for it every year.
Coliform bacteria3 of 7 wells had it
E. coli0 of 7 wells had it
E. coli means human or animal waste is getting in, so if a test of your Charleston County well finds it, boil drinking water until the well is fixed.
Iron reached staining levels in 5 of 17 tested wells, and it isn't a health risk.
Iron stains5 of 17 wells had it
Too few tested to show: Dorchester, Georgetown.
Most of the 18 wells tested in Charleston County were last tested before 2010.
An old result shows the water as it was then, so treat these 18 wells as a starting point and test your own.
Most Charleston County wells in these records were tested for research or because someone suspected a problem, which can push the shares above what a typical home well would show (how we read the numbers).
One mail-in lab test covers the 4 things to check in Charleston County.
- Bacteria
- Nitrate
- Fluoride
- Arsenic
What South Carolina offers well owners
- Free testingSCDES gives people over 65 or on public assistance one free coliform bacteria test and one free metals and minerals analysis per year, and fees may be waived or reduced based on ability to pay. See the program
- Certified labsSouth Carolina's list of certified labs
- Well recordsSouth Carolina's well record search
Half the household wells here are shallower than 500 feet.
That comes from 257 household wells in South Carolina's drilling records. Most wells of every kind here are 68 to 560 feet deep. Wells as deep as Charleston County's are usually better protected from fertilizer and bacteria at the surface, but they can pick up more of what's in the rock, like arsenic and uranium. That's the deepest typical depth for household wells among the 33 South Carolina counties with enough drilling records.
Look up your own well's depth in South Carolina's well record search, or see how to find it.
Well depths: US Groundwater Well Database
Here's what we know about radon and PFAS in Charleston County.
Charleston County is in the EPA's lowest radon zone, so radon from well water is unlikely to be a problem. Radon guide
Between 2023 and 2025 the EPA had 7 town water systems in Charleston County test for PFAS. 7 of them had at least one test above 4 ng/L, the new EPA limit for PFOA and PFOS. The highest single result was 8.5 ng/L of PFOS. No well in Charleston County has public PFAS results, so the town systems are the best clue to what's in the groundwater nearby. PFAS guide
Radon zones: EPA Map of Radon Zones. PFAS: EPA tests of town water systems, 2023 to 2025
Questions people ask about well water in Charleston County
Is well water in Charleston County safe to drink?
4 of 18 wells tested in Charleston County had fluoride over the limit, about 2 in 10. Across South Carolina it's about 1 in 33. That's the highest share among the 6 South Carolina counties with 10 or more tested wells. So test your own well for fluoride before you count on it.
Can I get my well tested for free in Charleston County?
SCDES gives people over 65 or on public assistance one free coliform bacteria test and one free metals and minerals analysis per year, and fees may be waived or reduced based on ability to pay. If not, use a lab South Carolina has certified for drinking water. Ask for bacteria, nitrate, fluoride and arsenic, the tests that matter most in Charleston County.
How deep are wells in Charleston County?
Half the household wells here are shallower than 500 feet. That's the deepest typical depth for household wells among the 33 South Carolina counties with enough drilling records.
How does Charleston County compare with the counties around it?
For fluoride, the share of tested wells over the limit: Charleston County, at 22%, had a higher share than all 2 neighboring counties with data. Groundwater doesn't stop at county lines, so Berkeley's 7% is worth knowing about if you live near it.
How often should I test my well in Charleston County?
In Charleston County, 3 of 7 tested wells had coliform bacteria, so the CDC's advice matters here: test for bacteria and nitrate every year, and right away after a flood, a repair, or any change in taste or smell.
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Where the Charleston County numbers come from
- People on wells: 26,768 in Charleston County, from EPA estimates built on the 2020 Census (Murray et al.).
- Lab tests: 434 well water samples from 18 wells in the Water Quality Portal, run by the USGS and EPA, 2000 to 2019.
- Well depths: 257 South Carolina drilling records for Charleston County, gathered in the US Groundwater Well Database (Lin and others, 2024).
- Neighboring counties: the 4 counties that share a border with Charleston County, from the Census Bureau's county adjacency file.
- PFAS: EPA tests of 7 town water systems in Charleston County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
- Radon: Charleston County is zone 3 on the EPA Map of Radon Zones.
- State programs and links: Department of Environmental Services (SCDES), checked November 1, 2026.