Home/ Directory/ CA/ COUNTY SERVICE AREA 7

Water system · PWSID CA4100509

COUNTY SERVICE AREA 7

REDWOOD CITY, CA · ~300 people served

Check your exact address → REDWOOD CITY overview
100
Excellent
PurityRadar safety score

PWSID

CA4100509

State

California

City

REDWOOD CITY

Population served

300

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

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

29

Violations on record

0

Unaddressed

7

Health-based

12

Enforcement actions

From EPA ECHO (SDWIS), most recent enforcement Sep 2025. Official EPA record →

Max contaminant level (MCL) · Haloacetic acids (HAA5) health-based began Jan 2025 Resolved
Max contaminant level (MCL) · Haloacetic acids (HAA5) health-based began Jan 2020 Resolved
Max contaminant level (MCL) · Total trihalomethanes (TTHM) health-based began Apr 2018 Resolved
Max contaminant level (MCL) · Total trihalomethanes (TTHM) health-based began Jan 2018 Resolved
Max contaminant level (MCL) · Total trihalomethanes (TTHM) health-based began Oct 2017 Resolved
Max contaminant level (MCL) · Total trihalomethanes (TTHM) health-based began Jul 2017 Resolved
Monitoring & reporting · EPA contaminant 2987 began Jan 2004 Resolved
Monitoring & reporting · EPA contaminant 2964 began Jan 2004 Resolved
Monitoring & reporting · EPA contaminant 2990 began Jan 2004 Resolved
Monitoring & reporting · EPA contaminant 2980 began Jan 2004 Resolved
Monitoring & reporting · EPA contaminant 2968 began Jan 2004 Resolved
Monitoring & reporting · EPA contaminant 2985 began Jan 2004 Resolved

Recent enforcement actions

  • State action · SOX Sep 2025
  • State action · SFL Jul 2025
  • State action · SOX Oct 2022
  • State action · SOX Feb 2021
  • State action · SFL May 2020
  • State action · SOX Feb 2018
  • State action · SFL Nov 2017
  • State action · SOX Dec 2009

This profile is built from EPA public records for system CA4100509 — 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.