Home/ Directory/ MA/ ONSET FIRE DISTRICTWATER DEPT.

Water system · PWSID MA4310003

ONSET FIRE DISTRICTWATER DEPT.

ONSET, MA · ~5,392 people served

Check your exact address → ONSET overview
73
Good
PurityRadar safety score

PWSID

MA4310003

State

Massachusetts

City

ONSET

Population served

5,392

Primary source

Groundwater

Score history

▼ 27 points — the score moved from 100 to 73 on Jun 18, 2026, as newly published EPA data was incorporated.

Jun 18, 2026 · score 100 Jun 18, 2026 · score 73

2 score updates logged since tracking began Jun 18, 2026. Each future EPA re-score adds a point.

PFAS & contaminant readings

Latest detections from EPA’s UCMR5 monitoring (through Jun 2025). Levels in parts per trillion (ppt).

PFOS

Perfluorooctanesulfonic acid

7.1 ppt

limit 4 ppt

Above EPA limit · 1.8×

Violations & enforcement

14

Violations on record

0

Unaddressed

8

Health-based

32

Enforcement actions

From EPA ECHO (SDWIS), most recent enforcement Jul 2023. Official EPA record →

Other · EPA contaminant 7000 began Jul 2022 Resolved
Monitoring & reporting · Lead & Copper Rule began Oct 2019 Resolved
Max contaminant level (MCL) · Total coliform health-based began Nov 2013 Resolved
Monitoring & reporting · Total coliform began Feb 2013 Resolved
Max contaminant level (MCL) · Total coliform health-based began Jan 2013 Resolved
Max contaminant level (MCL) · Total coliform health-based began Dec 2012 Resolved
Max contaminant level (MCL) · Total coliform health-based began Nov 2012 Resolved
Max contaminant level (MCL) · Total coliform health-based began Feb 2012 Resolved
Max contaminant level (MCL) · Total coliform health-based began Nov 2011 Resolved
Max contaminant level (MCL) · Total coliform health-based began Oct 2011 Resolved
Other · Total coliform began Oct 2011 Resolved
Monitoring & reporting · Lead & Copper Rule began Oct 2009 Resolved

Recent enforcement actions

  • State action · SFJ Jul 2023
  • State action · SFL Aug 2022
  • State action · SOX Aug 2022
  • State action · SOX Mar 2021
  • State action · SFL Mar 2021
  • State action · SFL Nov 2019
  • State action · SOX Sep 2014
  • State action · SFJ Sep 2014

Area water-quality monitoring

Environmental monitoring (rivers, wells, intakes) recorded in this system’s service area in the EPA/USGS Water Quality Portal since 2018 — source/ambient water, not finished tap water. Context for the watershed, not a reading from your tap.

ContaminantMedian · max · samples

Nitrate

28 stations · latest Oct 2022

1.76 · max 3.52 ppm · 30

Source: Water Quality Portal (EPA/USGS/state agencies). Values are as-reported and aren’t health thresholds.

This profile is built from EPA public records for system MA4310003 — SDWIS violations and UCMR5 PFAS sampling. The score is system-level and can’t account for your home’s plumbing (older pipes can add lead at the tap). For health decisions, check your exact address, read the utility’s Consumer Confidence Report, and confirm with your provider.