Charleston County Water Quality
Charleston County, South Carolina: one city report built from EPA and utility records. A county has many suppliers; each city shows the system that serves it.
Highest result for each contaminant
One row per contaminant: the highest result any system in the county reported, against its limit. Open a row for the systems behind it.
Perfluorooctanesulfonic acid (PFOS)CHARLESTON WATER SYSTEM (SC1010001)4.0 ng/L federal MCL (2024) · US EPA6.5 ng/L
- CHARLESTON WATER SYSTEM (SC1010001)6.5 ng/LSample date: 2025-03-24 to 2025-12-09
Perfluorooctanoic acid (PFOA)CHARLESTON WATER SYSTEM (SC1010001)4.0 ng/L federal MCL (2024) · US EPA4.7 ng/L
- CHARLESTON WATER SYSTEM (SC1010001)4.7 ng/LSample date: 2025-03-24 to 2025-12-09
Lead (90th percentile)CHARLESTON WATER SYSTEM (SC1010001)15 µg/L federal action level · US EPA3.5 µg/L
- CHARLESTON WATER SYSTEM (SC1010001)3.5 µg/LMonitoring period: 2022–2024
Perfluorobutanesulfonic acid (PFBS)CHARLESTON WATER SYSTEM (SC1010001)2,000 ng/L EPA health advisory (screening, not a legal limit) · US EPA4.3 ng/L
- CHARLESTON WATER SYSTEM (SC1010001)4.3 ng/LSample date: 2025-03-24 to 2025-12-09
Perfluorohexanoic acid (PFHxA)CHARLESTON WATER SYSTEM (SC1010001)400,000 ng/L Michigan EGLE state MCL (strictest US state) · Michigan EGLE4.6 ng/L
- CHARLESTON WATER SYSTEM (SC1010001)4.6 ng/LSample date: 2025-03-24 to 2025-12-09
Water hardnessCHARLESTON WATER SYSTEM (SC1010001)Aesthetic, no federal health limit · USGS3.2 gpg
- CHARLESTON WATER SYSTEM (SC1010001)3.2 gpgReporting year: 2026
Perfluoropentanoic acid (PFPeA)CHARLESTON WATER SYSTEM (SC1010001)No federal or state limit; shown for transparency5 ng/L
- CHARLESTON WATER SYSTEM (SC1010001)5 ng/LSample date: 2025-03-24 to 2025-12-09
25 substances tested, none detected in this systemShow
Tested in this system: CHARLESTON WATER SYSTEM (SC1010001)
- 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)
- 1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS)
- 1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS)
- 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)
- 4,8-Dioxa-3H-perfluorononanoic acid (ADONA)
- 9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)
- Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals)
- Lithium
- N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)
- N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)
- Nonafluoro-3,6-dioxaheptanoic acid (NFDHA)
- Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA)
- Perfluoro-3-methoxypropanoic acid (PFMPA)
- Perfluoro-4-methoxybutanoic acid (PFMBA)
- Perfluorobutanoic acid (PFBA)
- Perfluorodecanoic acid (PFDA)
- Perfluorododecanoic acid (PFDoA)
- Perfluoroheptanesulfonic acid (PFHpS)
- Perfluoroheptanoic acid (PFHpA)
- Perfluorohexanesulfonic acid (PFHxS)
- Perfluorononanoic acid (PFNA)
- Perfluoropentanesulfonic acid (PFPeS)
- Perfluorotetradecanoic acid (PFTA)
- Perfluorotridecanoic acid (PFTrDA)
- Perfluoroundecanoic acid (PFUnA)
Cities ranked by the records
Ranked by the Purity Score of each city's main water system, highest first. Scores belong to water systems; there is no county score. The score is computed only from contaminants measured in the published EPA record, so this ranks the record, not which city's water is safest. How the score works.
0of 1 city above the 15 µg/L action level
Based on each system's 90th-percentile result. Lead from household plumbing isn't in this record.
Lead in South Carolina1city reports hardness · Charleston, 3.2 gpg
None above 7 gpg, the USGS threshold for hard water. An aesthetic measure with no federal health limit.
Hard water explainedLargest water systems
- CharlestonCHARLESTON WATER SYSTEM (SC1010001) · SC1010001278,771 served
Frequently asked
How does Charleston County tap water compare across cities?
PurityMap ranks 1 city in Charleston County by the Purity Score of each city's main water system, computed only from contaminants measured in the published EPA record. Scores belong to water systems, not to cities. The highest published score is Charleston's main water system: CHARLESTON WATER SYSTEM (SC1010001) · PWSID SC1010001 · Purity Score 59 (Fair) · Confidence: moderate · Assessed at the water-system level. The ranking compares the records, not which city's water is safest, and your own tap can differ with household plumbing.
How many Charleston County cities had a PFAS sample above a 2024 EPA limit?
1 of 1 Charleston County city report had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing, including Charleston (PFOS 6.5 ng/L). That limit is judged on a yearly average, and water systems have until 2029 to meet it, so a single sample is not a violation. PFAS were detected at any level in 1.
Is there lead in Charleston County tap water?
Utilities report lead as a 90th-percentile result from home taps. 1 of 1 Charleston County cities reported a value above zero, and none was above the 15 µg/L federal action level. Lead usually comes from a building's own pipes and fixtures, so only a test at your tap tells you what you drink.
Does Charleston County have hard water?
Hardness is published in utility water-quality reports for 1 Charleston County city on record; the hardest is Charleston at 3.2 grains per gallon. Hardness affects scale and appliances; it is not a health finding.
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