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Water system · PWSID CA0410004

CITY OF GRIDLEY

GRIDLEY, CA · ~7,269 people served

Check your exact address → GRIDLEY overview
31
Action needed
PurityRadar safety score

PWSID

CA0410004

State

California

City

GRIDLEY

Population served

7,269

Primary source

Groundwater

Score history

▼ 54 points — the score moved from 85 to 31 on Jun 18, 2026, as newly published EPA data was incorporated.

Jun 18, 2026 · score 85 Jun 18, 2026 · score 31

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 Dec 2024). Levels in parts per trillion (ppt).

PFOS

Perfluorooctanesulfonic acid

9 ppt

limit 4 ppt

Above EPA limit · 2.3×

PFHxS

Perfluorohexanesulfonic acid

12 ppt

limit 10 ppt

Above EPA limit · 1.2×

PFNA

Perfluorononanoic acid

9.6 ppt

limit 10 ppt

Near EPA limit

PFPeA

6.2 ppt

limit —

No federal limit

PFHxA

5.2 ppt

limit —

No federal limit

PFHpA

3.2 ppt

limit —

No federal limit

Violations & enforcement

6

Violations on record

2

Unaddressed

4

Health-based

7

Enforcement actions

From EPA ECHO (SDWIS), most recent enforcement Feb 2018. Official EPA record →

Treatment technique · EPA contaminant 5200 health-based began Oct 2024 Unaddressed
Reporting · EPA contaminant 5200 began Oct 2024 Unaddressed
Max contaminant level (MCL) · Arsenic health-based began Oct 2008 Resolved
Max contaminant level (MCL) · Arsenic health-based began Jul 2007 Resolved
Monitoring & reporting · Nitrate began Jan 2002 Resolved
Max contaminant level (MCL) · Total coliform health-based began Mar 1999 Resolved

Recent enforcement actions

  • State action · SOX Feb 2018
  • State action · SFL Feb 2015
  • State action · SOX Dec 2007
  • State action · SOX Nov 2007
  • State action · SIA Mar 2003
  • State action · SOX Apr 1999
  • State action · SIE Apr 1999

Area water-quality monitoring

Environmental monitoring (rivers, wells, intakes) recorded in this system’s service area in the EPA/USGS Water Quality Portal since 2018 — source/ambient water, not finished tap water. Context for the watershed, not a reading from your tap.

ContaminantMedian · max · samples

Nitrate

1 station · latest Jun 2021

2.24 · max 2.24 mg/l as N · 2

Arsenic

1 station · latest Jun 2021

7.1 · max 7.1 ug/l · 1

Atrazine

1 station · latest Jun 2021

0.007 · max 0.007 ug/l · 1

Copper

1 station · latest Jun 2021

3.3 · max 3.3 ug/l · 1

Fluoride

1 station · latest Jun 2021

0.16 · max 0.16 mg/l · 1

Uranium

1 station · latest Jun 2021

2.29 · max 2.29 ug/l · 1

Source: Water Quality Portal (EPA/USGS/state agencies). Values are as-reported and aren’t health thresholds.

This profile is built from EPA public records for system CA0410004 — 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.