YOSEMITE WEST WATER SYSTEM

MARIPOSA, CA · ~420 people served

Check your exact address → MARIPOSA overview

100

Excellent

PurityRadar safety score

PWSID

CA2210924

State

California

City

MARIPOSA

Population served

420

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

No PFAS detections are on record for this system from EPA’s UCMR5 monitoring (2023–25). Absence of a detection isn’t a guarantee — not every system was sampled, and this dataset doesn’t cover other contaminants.

Violations & enforcement

Violations on record

Unaddressed

Health-based

Enforcement actions

From EPA ECHO (SDWIS), most recent enforcement Sep 2015. Official EPA record →

Monitoring & reporting · Lead & Copper Rule began Oct 2025 Unaddressed

Monitoring & reporting · Nitrate began Jan 2012 Resolved

Max contaminant level (MCL) · Total coliform health-based began Jul 2011 Resolved

Max contaminant level (MCL) · Total coliform health-based began Oct 2010 Resolved

Max contaminant level (MCL) · Total coliform health-based began Sep 2009 Resolved

Max contaminant level (MCL) · Total coliform health-based began Sep 2008 Resolved

Monitoring & reporting · Total coliform began Feb 2006 Resolved

Monitoring & reporting · Lead & Copper Rule began Mar 2004 Resolved

Monitoring & reporting · Nitrate began Jan 2003 Resolved

Max contaminant level (MCL) · Total coliform health-based began Jun 2002 Resolved

Monitoring & reporting · Nitrate began Jan 2001 Resolved

Max contaminant level (MCL) · Total coliform health-based began Dec 1996 Resolved

Recent enforcement actions

State action · SOX Sep 2015
State action · SIA Mar 2015
State action · SOX Mar 2014
State action · SFL Feb 2013
State action · SOX Aug 2011
State action · SFL Aug 2011
State action · SOX Nov 2010
State action · SFL Oct 2010

This profile is built from EPA public records for system CA2210924 — 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.