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Water system · PWSID CA3910015

CITY OF LATHROP

LATHROP, CA · ~35,080 people served

Check your exact address → LATHROP overview
67
Fair
PurityRadar safety score

PWSID

CA3910015

State

California

City

LATHROP

Population served

35,080

Primary source

SWP

Score history

▼ 33 points — the score moved from 100 to 67 on Jun 18, 2026, as newly published EPA data was incorporated.

Jun 18, 2026 · score 100 Jun 18, 2026 · score 67

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 Jul 2024). Levels in parts per trillion (ppt).

PFOS

Perfluorooctanesulfonic acid

13 ppt

limit 4 ppt

Above EPA limit · 3.3×

PFHxS

Perfluorohexanesulfonic acid

3.5 ppt

limit 10 ppt

Below EPA limit

PFBS

3.7 ppt

limit —

No federal limit

Violations & enforcement

48

Violations on record

0

Unaddressed

42

Health-based

18

Enforcement actions

From EPA ECHO (SDWIS), most recent enforcement Dec 2022. Official EPA record →

Monitoring & reporting · Total trihalomethanes (TTHM) began Jul 2018 Resolved
Monitoring & reporting · Haloacetic acids (HAA5) began Jul 2018 Resolved
Max contaminant level (MCL) · Combined radium-226/228 health-based began Apr 2014 Resolved
Max contaminant level (MCL) · Arsenic health-based began Apr 2014 Resolved
Max contaminant level (MCL) · Combined radium-226/228 health-based began Jan 2014 Resolved
Max contaminant level (MCL) · Arsenic health-based began Jan 2014 Resolved
Max contaminant level (MCL) · Combined radium-226/228 health-based began Oct 2013 Resolved
Max contaminant level (MCL) · Arsenic health-based began Oct 2013 Resolved
Max contaminant level (MCL) · Arsenic health-based began Jul 2013 Resolved
Max contaminant level (MCL) · Combined radium-226/228 health-based began Jul 2013 Resolved
Max contaminant level (MCL) · Arsenic health-based began Apr 2013 Resolved
Max contaminant level (MCL) · Combined radium-226/228 health-based began Apr 2013 Resolved

Recent enforcement actions

  • State action · SOX Dec 2022
  • State action · SFL Oct 2018
  • State action · SOX Dec 2014
  • State action · SFL Oct 2012
  • State action · SOX Jul 2012
  • State action · SFL Dec 2008
  • State action · SOX Mar 2006
  • State action · SFL Mar 2006

This profile is built from EPA public records for system CA3910015 — 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.