Is there PFAS in Rock Hill tap water?+
Two PFAS were detected; none has a federal limit. In EPA UCMR 5 testing of ROCK HILL CITY OF (SC4610002) (2023-10-10 to 2024-07-09): PFHxA 4.4 ng/L (state limit 400,000), PFPeA 5.9 ng/L (no federal or state limit) and the other 27 PFAS tested not detected. "Not detected" means below the lab's reporting limit, not proven zero.
What are the federal PFAS limits?+
EPA's 2024 drinking-water rule set maximum contaminant levels of 4.0 ng/L for PFOA and for PFOS, and 10 ng/L for PFHxS, PFNA and HFPO-DA (GenX). In May 2026 EPA proposed keeping the PFOA and PFOS limits, with the option of until 2031 to comply, and rescinding the other three. Until a final rule, all five limits apply. The 2024 rule also set a Hazard Index of 1 for mixtures of two or more of PFHxS, PFNA, GenX and PFBS; EPA has proposed rescinding it, and it applies until a final rule.
Are PFHxA and PFPeA regulated?+
No. They have no federal drinking-water limit (MCL); the 2024 rule sets limits only for PFOA, PFOS, PFHxS, PFNA and HFPO-DA (GenX). PFHxA has a 400,000 ng/L state limit. Rock Hill's results: PFHxA 4.4 ng/L and PFPeA 5.9 ng/L.
Does "not detected" mean zero PFAS?+
No. "Not detected" (ND) means the result was below the lab's reporting limit, not that the compound is absent. In Rock Hill's record, 27 of the 29 PFAS tested were not detected. Their reporting limits run from 2 to 20 ng/L.
Which PFAS were tested in Rock Hill?+
29 PFAS compounds in EPA UCMR 5 testing of ROCK HILL CITY OF (SC4610002) (2023-10-10 to 2024-07-09), including the five with federal limits. PFHxA and PFPeA were detected. PFAS not on that list have no result here.
Can my tap have different PFAS levels than the city report?+
Yes. These results describe the water system as a whole, and levels vary between samples and sources over time. PFAS come with the water rather than from home plumbing, so your tap usually reflects the system's water, but only a certified lab test of your own tap gives a number for your glass.
How do I test my tap for PFAS?+
Use a state-certified lab that runs EPA Method 533 or 537.1, the methods behind the federal results. Ask which compounds are on the panel, so PFHxA and PFPeA are included, and keep the reporting limit with your result. No home test strip has been shown to detect PFAS at the levels federal limits use.
What filter removes PFAS from Rock Hill water?+
Reverse osmosis (NSF/ANSI 58), activated carbon (NSF/ANSI 53) and anion exchange can reduce PFAS, but certification is compound by compound. Choose a model whose current listing names the compound you need to reduce, here PFHxA and PFPeA, check it in the certifier's listing (NSF, WQA or IAPMO), and replace cartridges on schedule.
Is there a filter certified for PFHxA and PFPeA?+
Look for PFHxA and PFPeA by name in the certifier's listing (NSF, WQA or IAPMO) for the exact model: NSF/ANSI 53 and 58 listings name each PFAS a filter was tested to reduce. A listing for PFOA and PFOS alone does not cover PFHxA and PFPeA.
When must Rock Hill meet the PFAS limits?+
Compliance with the 2024 limits is judged on a running annual average, with a compliance date of 2029 (EPA has proposed allowing until 2031 for PFOA and PFOS). EPA has proposed rescinding the PFHxS, PFNA, GenX and Hazard Index limits; they apply until a final rule.