Is There PFAS in Philadelphia Tap Water?

Two PFAS each had a sample above a 2024 EPA limit. In EPA UCMR 5 testing of PHILADELPHIA WATER DEPARTMENT (2024-01-08 to 2024-10-07): PFOA 8.1 ng/L (limit 4), PFOS 6 ng/L (limit 4), PFNA 4.5 ng/L (limit 10), PFBS 10 ng/L (EPA health advisory 2,000), PFHxA 9.1 ng/L (state limit 400,000), PFPeA 9.9 ng/L (no federal or state limit), PFBA 7.6 ng/L (no federal or state limit), PFHpA 3.3 ng/L (no federal or state limit) and the other 21 PFAS tested not detected. "Not detected" means below the lab's reporting limit, not proven zero.

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.

No. They have no federal drinking-water limit (MCL); the 2024 rule sets limits only for PFOA, PFOS, PFHxS, PFNA and HFPO-DA (GenX). PFBS has no limit of its own; the 2024 rule counts it only inside the Hazard Index for mixtures, which EPA has proposed rescinding. PFBS has an EPA health advisory of 2,000 ng/L, a screening level, not a legal limit. PFHxA has a 400,000 ng/L state limit. Philadelphia's results: PFBS 10 ng/L, PFHxA 9.1 ng/L, PFPeA 9.9 ng/L, PFBA 7.6 ng/L and PFHpA 3.3 ng/L.

No. "Not detected" (ND) means the result was below the lab's reporting limit, not that the compound is absent. In Philadelphia's record, 21 of the 29 PFAS tested were not detected. Their reporting limits run from 2 to 20 ng/L.

29 PFAS compounds in EPA UCMR 5 testing of PHILADELPHIA WATER DEPARTMENT (2024-01-08 to 2024-10-07), including the five with federal limits. PFOA, PFOS, PFNA, PFBS, PFHxA, PFPeA, PFBA and PFHpA were detected. PFAS not on that list have no result here.

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.

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 PFOA, PFOS and PFNA 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.

Reverse osmosis, activated carbon and anion exchange can reduce PFAS, but certification is compound by compound. Look for NSF/ANSI 53 or 58 naming the compound; RO systems often carry it under 53. Choose a model whose current listing names the compound you need to reduce, here PFOA, PFOS and PFNA, check it in the certifier's listing (NSF, WQA or IAPMO), and replace cartridges on schedule.

Look for PFOA, PFOS and PFNA 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 PFNA.

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.