ZIP 11550: your water comes from Hempstead (V)
Hempstead (V) is the only community water system that reports serving ZIP 11550 (Hempstead, Nassau County, New York) under EPA's UCMR 5 (reported by the system to EPA). PFAS-4 at the latest sample (2024): 4.7 ng/L. Systems report their own ZIP lists to EPA; if your water bill names another utility, that utility's page carries its own results.
Where this ZIP is
This site is a data project, not an official source. If in doubt, check with your water supplier or local authority.