RIO ALTO WATER DISTRICT

COTTONWOOD, CA · ~3,329 people served

Check your exact address → COTTONWOOD overview

100

Excellent

PurityRadar safety score

PWSID

CA5210005

State

California

City

COTTONWOOD

Population served

3,329

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 Jan 2019. Official EPA record →

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

Monitoring & reporting · Total coliform began May 2012 Resolved

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

Monitoring & reporting · Total coliform began Jan 2004 Resolved

Monitoring & reporting · Lead & Copper Rule began Jul 1993 Resolved

Recent enforcement actions

State action · SOX Jan 2019
State action · SOX Jul 2015
State action · SFL May 2015
State action · SOX Jul 2012
State action · SIE Jul 2012
State action · SOX Dec 2010
State action · SFJ Dec 2010
EPA/federal action · EOX Mar 2000

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 Dec 2022

0.989 · max 0.989 mg/l as N · 2

Arsenic

1 station · latest Dec 2022

2.5 · max 2.5 ug/l · 1

Fluoride

1 station · latest Dec 2022

0.12 · max 0.12 mg/l · 1

Lead

1 station · latest Dec 2022

1.64 · max 1.64 ug/l · 1

Uranium

1 station · latest Dec 2022

0.279 · max 0.279 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 CA5210005 — 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.