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Water system · PWSID CA4010002

ATASCADERO MUTUAL WATER CO

ATASCADERO, CA · ~30,618 people served

Check your exact address → ATASCADERO overview
52
Fair
PurityRadar safety score

PWSID

CA4010002

State

California

City

ATASCADERO

Population served

30,618

Primary source

Groundwater

Score history

▼ 48 points — the score moved from 100 to 52 on Jun 18, 2026, as newly published EPA data was incorporated.

Jun 18, 2026 · score 100 Jun 18, 2026 · score 52

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).

PFOA

Perfluorooctanoic acid

7.4 ppt

limit 4 ppt

Above EPA limit · 1.9×

PFOS

Perfluorooctanesulfonic acid

5.1 ppt

limit 4 ppt

Above EPA limit · 1.3×

PFHxS

Perfluorohexanesulfonic acid

3.1 ppt

limit 10 ppt

Below EPA limit

Lithium

20,400 ppt

limit —

No federal limit

PFBA

10 ppt

limit —

No federal limit

PFBS

3.7 ppt

limit —

No federal limit

Violations & enforcement

1

Violations on record

0

Unaddressed

1

Health-based

3

Enforcement actions

From EPA ECHO (SDWIS), most recent enforcement May 1993. Official EPA record →

Treatment technique · EPA contaminant 0200 health-based began Jun 1993 Resolved

Recent enforcement actions

  • EPA/federal action · EFJ May 1993
  • State action · SOX Jan 1993
  • State action · SOX Jan 1993

This profile is built from EPA public records for system CA4010002 — 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.