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Water system · PWSID CA4810004

CITY OF RIO VISTA

RIO VISTA, CA · ~10,489 people served

Check your exact address → RIO VISTA overview
100
Excellent
PurityRadar safety score

PWSID

CA4810004

State

California

City

RIO VISTA

Population served

10,489

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

Lithium

12,000 ppt

limit —

No federal limit

Violations & enforcement

6

Violations on record

0

Unaddressed

3

Health-based

13

Enforcement actions

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

Monitoring & reporting · EPA contaminant 2990 began Jul 2000 Resolved
Max contaminant level (MCL) · Total coliform health-based began Jan 1995 Resolved
Max contaminant level (MCL) · Total coliform health-based began Oct 1994 Resolved
Max contaminant level (MCL) · Total coliform health-based began Jun 1994 Resolved
Monitoring & reporting · Lead & Copper Rule began Jul 1993 Resolved
Monitoring & reporting · Arsenic began Jul 1990 Resolved

Recent enforcement actions

  • State action · SOX Feb 2018
  • State action · SOX Feb 2018
  • State action · SIA Oct 2000
  • EPA/federal action · EOX Mar 2000
  • EPA/federal action · EF! Sep 1995
  • State action · SOX Feb 1995
  • State action · SIA Feb 1995
  • State action · SOX Nov 1994

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 Jul 2020

0.406 · max 0.406 mg/l as N · 2

Arsenic

1 station · latest Jul 2020

7.4 · max 7.4 ug/l · 1

Fluoride

1 station · latest Jul 2020

0.21 · max 0.21 mg/l · 1

Lead

1 station · latest Jul 2020

0.105 · max 0.105 ug/l · 1

Manganese

1 station · latest Jul 2020

9.12 · max 9.12 ug/l · 1

Uranium

1 station · latest Jul 2020

1.73 · max 1.73 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 CA4810004 — 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.