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Water system · PWSID CA4010009

SAN LUIS OBISPO WATER DEPARTMENT

SAN LUIS OBISPO, CA · ~47,788 people served

Check your exact address → SAN LUIS OBISPO overview
100
Excellent
PurityRadar safety score

PWSID

CA4010009

State

California

City

SAN LUIS OBISPO

Population served

47,788

Primary source

Surface water

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

Lithium

10,000 ppt

limit —

No federal limit

Violations & enforcement

1

Violations on record

0

Unaddressed

1

Health-based

2

Enforcement actions

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

Max contaminant level (MCL) · Total trihalomethanes (TTHM) health-based began Apr 2015 Resolved

Recent enforcement actions

  • State action · SFL Jul 2015
  • State action · SOX Jul 2015

This profile is built from EPA public records for system CA4010009 — 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.