TOWN OF DISCOVERY BAY

DISCOVERY BAY, CA · ~16,790 people served

Check your exact address → DISCOVERY BAY overview

100

Excellent

PurityRadar safety score

PWSID

CA0710009

State

California

City

DISCOVERY BAY

Population served

16,790

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 Oct 2023). Levels in parts per trillion (ppt).

Lithium

13,000 ppt

limit —

No federal limit

Violations & enforcement

Violations on record

Unaddressed

Health-based

Enforcement actions

From EPA ECHO (SDWIS), most recent enforcement Oct 1997. Official EPA record →

Max contaminant level (MCL) · Total coliform health-based began Sep 1997 Resolved

Max contaminant level (MCL) · Total coliform health-based began Aug 1993 Resolved

Max contaminant level (MCL) · Total coliform health-based began Jul 1992 Resolved

Recent enforcement actions

State action · SOX Oct 1997
State action · SFJ Oct 1997
State action · SOX Sep 1993
State action · SFJ Sep 1993
State action · SOX Aug 1992
State action · SFJ Jul 1992

This profile is built from EPA public records for system CA0710009 — 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.