County Water Quality Report

Orange County, California

21 public water systems serving 3,805,531 residents

Data sources: EPA SDWIS EPA ECHO EWG Tap Water Database Utility CCRs ⓘ How did we get these ratings?
County average grade
F
56/100
Utilities rated 21
Population served 3,805,531
Most recent test 2024

Top water quality concerns in Orange County

  • Haloacetic acids (HAA5) significantly above health guidelinein 18 of 21 utilities
  • PFAS contaminationin 14 of 21 utilities
  • Perfluorohexane sulfonate (PFHXS) significantly above health guidelinein 13 of 21 utilities
  • Arsenic significantly above health guidelinein 11 of 21 utilities
  • Total trihalomethanes (TTHMs) significantly above health guidelinein 7 of 21 utilities

All utilities in Orange County

Click any utility for full grade card, contaminant data, and treatment plant contact info.

B
80/100

City of Anaheim Water Department

Anaheim · 350,000 residents

Top concern: Haloacetic Acids (HAA5) significantly above health guideline

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C
74/100

Irvine Water Authority

Irvine · 308,000 residents

Top concern: Lead detected in source water

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C
67/100

MOULTON NIGUEL WATER DISTRICT

LAGUNA HILLS · 170,236 residents

Top concern: Haloacetic acids (HAA5) significantly above health guideline

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C
67/100

SANTA MARGARITA WATER DISTRICT

RANCHO SANTA MARGARITA · 168,289 residents

Top concern: Haloacetic acids (HAA5) significantly above health guideline

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C
65/100

Santa Ana Water Utilities

Santa Ana · 333,000 residents

Top concern: Arsenic significantly above health guideline

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D
64/100

CITY OF LA HABRA

LA HABRA · 63,118 residents

Top concern: Haloacetic acids (HAA5) significantly above health guideline

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D
62/100

MESA WATER DISTRICT

COSTA MESA · 110,000 residents

Top concern: Arsenic significantly above health guideline

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D
58/100

CITY OF FOUNTAIN VALLEY

FOUNTAIN VALLEY · 56,747 residents

Top concern: PFAS contamination

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F
53/100

CITY OF BUENA PARK

BUENA PARK · 81,998 residents

Top concern: PFAS contamination

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F
53/100

CITY OF NEWPORT BEACH

NEWPORT BEACH · 68,572 residents

Top concern: PFAS contamination

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F
52/100

CITY OF FULLERTON

FULLERTON · 139,461 residents

Top concern: PFAS contamination

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F
52/100

CITY OF ORANGE

ORANGE · 120,770 residents

Top concern: PFAS contamination

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F
52/100

YORBA LINDA WATER DISTRICT

PLACENTIA · 84,292 residents

Top concern: PFAS contamination

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F
52/100

CITY OF TUSTIN

TUSTIN · 66,600 residents

Top concern: PFAS contamination

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F
48/100

CITY OF HUNTINGTON BEACH

HUNTINGTON BEACH · 201,000 residents

Top concern: PFAS contamination

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F
47/100

CITY OF ANAHEIM

ANAHEIM · 348,593 residents

Top concern: PFAS contamination

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F
47/100

GOLDEN STATE WC - WEST ORANGE COUNTY

ANAHEIM · 114,379 residents

Top concern: PFAS contamination

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F
47/100

CITY OF SANTA ANA

SANTA ANA · 310,539 residents

Top concern: PFAS contamination

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F
47/100

CITY OF GARDEN GROVE

GARDEN GROVE · 174,226 residents

Top concern: PFAS contamination

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F
47/100

CITY OF WESTMINSTER

WESTMINSTER · 90,911 residents

Top concern: PFAS contamination

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F
47/100

IRVINE RANCH WATER DISTRICT

IRVINE · 444,800 residents

Top concern: PFAS contamination

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