public water systems available in the ZIP lookup
EPA sampling locations represented in the lookup
active community water systems with enough required samples for a yearly average
of those systems with at least one yearly average at or above an EPA-based study benchmark
Water-system results by state
Each water system is counted once. Select a heading to sort the results.
Key terms: “Complete monitoring” means that, for at least one sampling location, a system had every required sample needed to calculate a yearly average. It does not mean every location or home was tested. An “EPA-based study benchmark” is a fixed, unrounded research cutoff used to reproduce EPA’s January 2026 technical-assistance classification based on the April 2024 federal levels. It is not a current federal or state standard. The table does not rank water quality or determine compliance, household tap-water levels, personal exposure, or health risk. A lower count does not mean PFAS was absent.
Sort the columns to compare systems with enough required samples for a yearly average and results at or above the study benchmarks across states.
Select a state name to see compound results and the water systems included in that state’s count.
Review how the site works for inclusion rules, exact calculations, and limitations.