ZIP 01778: your water comes from Wayland Water Department
Wayland Water Department is the only community water system that reports serving ZIP 01778 (Middlesex County, Massachusetts) under EPA's UCMR 5. PFAS-4 at the latest sample (2023): 12 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.