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Water system · PWSID CA2210002

PONDEROSA BASIN MUTUAL WTR CO

MARIPOSA, CA · ~798 people served

Check your exact address → MARIPOSA overview
100
Excellent
PurityRadar safety score

PWSID

CA2210002

State

California

City

MARIPOSA

Population served

798

Primary source

Groundwater

Score history

No change since tracking began Jun 18, 2026.

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

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 2025). Levels in parts per trillion (ppt).

Lithium

108,000 ppt

limit —

No federal limit

Violations & enforcement

15

Violations on record

0

Unaddressed

8

Health-based

29

Enforcement actions

From EPA ECHO (SDWIS), most recent enforcement Jul 2025. Official EPA record →

Monitoring & reporting · Lead & Copper Rule began Oct 2024 Addressed
Monitoring & reporting · Nitrate began Jan 2014 Resolved
Max contaminant level (MCL) · Total coliform health-based began Jul 2013 Resolved
Max contaminant level (MCL) · Total coliform health-based began Aug 2007 Resolved
Max contaminant level (MCL) · Total coliform health-based began Feb 2007 Resolved
Monitoring & reporting · Total coliform began Aug 2006 Resolved
Max contaminant level (MCL) · Total coliform health-based began Jun 2006 Resolved
Monitoring & reporting · Total coliform began Oct 2004 Resolved
Max contaminant level (MCL) · Total coliform health-based began Oct 2004 Resolved
Monitoring & reporting · Total coliform began Dec 2001 Resolved
Monitoring & reporting · EPA contaminant 4030 began Jan 2001 Resolved
Max contaminant level (MCL) · Total coliform health-based began Jul 1998 Resolved

Recent enforcement actions

  • State action · SFL Jul 2025
  • State action · SOX Aug 2015
  • State action · SIA Feb 2015
  • State action · SOX Oct 2013
  • State action · SFL Aug 2013
  • State action · SOX Jan 2009
  • State action · SIA Jan 2009
  • State action · SOX Apr 2008

This profile is built from EPA public records for system CA2210002 — 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.