Is there PFAS in Charleston Water System (sc1010001) water?
Yes. EPA's final UCMR 5 results show Charleston Water System (sc1010001) averaged 5.8 ppt of PFOS at its worst sampling point, 1.4 times the EPA limit of 4 ppt.
Charleston Water System (sc1010001)
Serves 327,422 people · 4 PFOA samples from 1 sampling point · Mar 2025 to Dec 2025
Average above an EPA limit
PFOA Perfluorooctanoic acid
4.3 ppt avg · max 4.7
PFOS Perfluorooctanesulfonic acid
5.8 ppt avg · max 6.5
Hazard index GenX, PFBS, PFNA, PFHxS combined
not detected
Also detected, no federal limit: PFPeA, PFHxA, PFBS.
Charleston Water System (sc1010001) is a public water system drawing on surface water, based in Charleston, South Carolina, serving about 327,422 people, including Charleston, Charleston Afb, North Charleston, Hanahan, Adams Run, Awendaw. Under EPA's Fifth Unregulated Contaminant Monitoring Rule it was tested for 29 PFAS and lithium 4 times across 1 sampling point between Mar 2025 and Dec 2025.
Every PFAS detected
Not detected: PFTA, PFTrDA, 6:2 FTS, NEtFOSAA, 8:2 FTS, NMeFOSAA, 4:2 FTS, PFHpA, PFHpS, PFPeS, NFDHA, PFEESA, PFMBA, PFBA, PFMPA, PFHxS, PFDoA, HFPO-DA, ADONA, 9Cl-PF3ONS, 11Cl-PF3OUdS, PFUnA, PFNA, PFDA.
Lithium, tested in the same program: not detected.
What the EPA limits mean here
In April 2024 EPA set enforceable limits of 4 ppt for PFOA and PFOS, 10 ppt each for PFHxS, PFNA and GenX, and a hazard index of 1 for mixtures. Utilities were given until 2029 to comply. In May 2026 EPA proposed keeping only the PFOA and PFOS limits and moving that deadline to 2031. Until that proposal is final, the 2024 limits stand.
Compliance is judged on a running annual average at each entry point, so we show the average at this system's worst sampling point next to its single highest result. UCMR 5 results do not by themselves put a utility in or out of compliance.
What you can do at home
Two routes work for PFAS. For drinking and cooking water only, a reverse osmosis system certified to NSF/ANSI 58 with a PFOA/PFOS reduction claim is the cheapest proven option. To treat every tap and shower, a whole-house carbon system with enough contact time works, but check that the maker has PFAS test data, not just a marketing claim. See the best filters for PFAS and how PFAS removal works.
Other systems in South Carolina
All 165 tested systems in South Carolina
ZIP codes served
29401 29403 29404 29405 29406 29407 29409 29410 29412 29414 29418 29420 29424 29425 29426 29429 29439 29445 29449 29450 29451 29455 29456 29461 29464 29466 29470 29482 29483 29485 29486 29487 29492
As reported by the utility to EPA. Neighbouring ZIPs are often split between systems; your water bill names yours.
Cite this page
Well & Tap. "PFAS in Charleston Water System (sc1010001) water: EPA UCMR 5 results." Data: U.S. EPA Fifth Unregulated Contaminant Monitoring Rule, final release August 2026, PWSID SC1010001. https://wellandtap.com/pfas/south-carolina/charleston-water-system-sc1010001/
About this data
Source: U.S. EPA, UCMR 5 occurrence data, final release August 2026 (PWSID SC1010001). Population: EPA SDWIS. Averages count results below the reporting level as zero, the same convention EPA uses for running annual averages. Full method.
