Is there PFAS in your tap water?

The EPA's national survey found PFAS above the 4 parts per trillion federal limit in 1,711 of the 10,313 public water systems it tested, and detected PFAS at any level in 3,595 of them.

Under the fifth Unregulated Contaminant Monitoring Rule the EPA required almost every public water system in the country to test for 29 PFAS compounds and published every result. These pages are those results, system by system, with what each reading means against the federal limit and which filters remove it.

Find your state

What to do about it

Boiling does not remove PFAS, it concentrates it. Reverse osmosis and certified activated carbon do. We grade water filters 0 to 100 on the chemistry of the filter itself, which is a separate question from how well it filters, and both matter.

Source, the EPA’s fifth Unregulated Contaminant Monitoring Rule, final dataset published 2026-10-15. Original data → Free to cite with attribution and a link. Lithium is in the same survey and is not a PFAS; it is excluded everywhere here.