💧 ZIP Water Report

Onset Fire Districtwater Dept.

PWSID MA4310003 · Onset, Massachusetts · serves 5,392 people · groundwater source

D
Poor

PFAS test results (EPA UCMR 5)

ContaminantResultFederal limit (MCL)Sampled
PFOS 7.1 ppt 4 ppt 6/24/2025
PFOS 5.2 ppt 4 ppt 12/2/2025

ppt = parts per trillion (ng/L). Rows highlighted red meet or exceed the 2024 federal limit.

Violation history

DateViolationTypeHealth-basedStatus
2022-07-01 Consumer Confidence Rule Other No Resolved

ZIP codes served