STATE REPORT CA 5 ALERTS 80 HEALTH VIOLATIONS

California Water Quality & Safety Report

48 ZIP codes · 166 water systems · UPC plumbing code · Updated 2026-03-16

Data: EPA SDWIS, NWS, State plumbing boards, Rewiring America Last verified: 2026-03-16

48
ZIP Codes
166
Water Systems
27
ZIPs with Violations
5
Active Alerts
UPC
Plumbing Code
C · 65
Avg Safety Score

Overview

We track water quality, weather alerts, plumbing regulations, and energy rebates for 48 ZIP codes across California, covering 166 community water systems that serve approximately 15,837,555 people.

27 of 48 ZIP codes (56%) have recorded EPA violations. 80 health-based violations have been documented.

Active Weather Alerts

5 active alerts in California. Severe weather can directly affect tap water quality — flooding, power outages, and infrastructure damage may lead to boil-water advisories.

AlertSeverityAreas
Heat AdvisoryModerateSan Francisco; Marin Coastal Range; Sonoma Coastal Range;…
Heat AdvisoryModerateSan Diego County Coastal Areas; San Bernardino and Rivers…
Heat AdvisoryModerateSanta Clarita Valley; Santa Lucia Mountains; San Luis Obi…
Heat AdvisoryModerateCatalina and Santa Barbara Islands; San Luis Obispo Count…
Heat AdvisoryModerateSan Miguel and Santa Rosa Islands; Santa Cruz and Anacapa…

View all California alerts →

Plumbing Regulations

California follows the California Plumbing Code (based on UPC) (2022 edition).

  • Plumbing code: UPC (2022)
  • Homeowner DIY: Licensed plumber required
  • Water heater permit: Required
  • Annual backflow test: Required
  • Seismic strapping: Required

Full California regulations →

Areas with Most Violations

ZIP CodeCitySafety ScoreViolationsHealth-BasedSystem
90801Long Beach—423LONG BEACH UTILITIES DEPARTMENT
96150South Lake Tahoe—420SOUTH TAHOE PUD - MAIN
92101San Diego—2913SAN DIEGO, CITY OF
91501Burbank—240BURBANK-CITY, WATER DEPT.
93001Ventura—229VENTURA WATER DEPARTMENT
92602Irvine—190IRVINE RANCH WATER DISTRICT
92605Huntington Beach—197CITY OF HUNTINGTON BEACH
94536Fremont—181ALAMEDA COUNTY WATER DISTRICT
93301Bakersfield—1716BAKERSFIELD, CITY OF
95201Stockton—1611CITY OF STOCKTON

Areas with No Violations

ZIP CodeCitySafety ScoreSystemPopulation
90401Santa Monica—SANTA MONICA-CITY, WATER DIVISION89,947
90501Torrance—TORRANCE-CITY, WATER DEPT.106,183
90601Whittier—WHITTIER-CITY, WATER DEPT.49,954
91201Glendale—GLENDALE-CITY, WATER DEPT.188,784
91801Alhambra—LOS ANGELES CWWD 40 REG 4 & 34 LANCASTER208,129
91909Chula Vista—SWEETWATER AUTHORITY191,282
92008Carlsbad—CARLSBAD MWD95,158
92025Escondido—ESCONDIDO, CITY OF137,044
92049Oceanside—OCEANSIDE, CITY OF171,483
92331Fontana—SAN GABRIEL VALLEY WC - FONTANA237,700

Home Safety Score

Average Home Safety Score for California: C (65/100)

Lead & Copper

  • Average lead level (90th percentile): 0.0006 mg/L (EPA action level: 0.015 mg/L)
  • 0 ZIP codes exceed the EPA lead action level

Radon Risk

  • High risk (Zone 1): 0 ZIP codes (0%)
  • Moderate risk (Zone 2): 1 ZIP code
  • Low risk (Zone 3): 0 ZIP codes

All 48 ZIP Codes in California

Data Sources

Updated daily.

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