County Water Quality Report

San Diego County, California

14 public water systems serving 4,726,390 residents

Data sources: EPA SDWIS EPA ECHO EWG Tap Water Database Utility CCRs ⓘ How did we get these ratings?
County average grade
D
63/100
Utilities rated 14
Population served 4,726,390
Most recent test 2024

Top water quality concerns in San Diego County

  • Haloacetic acids (HAA5) significantly above health guidelinein 12 of 14 utilities
  • Haloacetic acids (HAA9) significantly above health guidelinein 12 of 14 utilities
  • Total trihalomethanes (TTHMs) significantly above health guidelinein 8 of 14 utilities
  • PFAS contaminationin 5 of 14 utilities
  • Arsenic* significantly above health guidelinein 3 of 14 utilities

All utilities in San Diego County

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

B
82/100

HELIX WATER DISTRICT

LA MESA · 277,668 residents

Top concern: Haloacetic acids (HAA9) significantly above health guideline

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B
76/100

San Diego Water Utilities

San Diego · 1,424,000 residents

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

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C
69/100

Chula Vista Water Utilities

Chula Vista · 274,000 residents

Top concern: Lead detected in source water

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C
67/100

VISTA IRRIGATION DISTRICT

VISTA · 132,430 residents

Top concern: Haloacetic acids (HAA9) significantly above health guideline

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C
67/100

OTAY WATER DISTRICT

SPRING VALLEY · 238,008 residents

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

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C
67/100

PADRE DAM MWD

SANTEE · 93,980 residents

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

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D
64/100

ESCONDIDO, CITY OF

ESCONDIDO · 137,044 residents

Top concern: Haloacetic acids (HAA9) significantly above health guideline

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D
64/100

SWEETWATER AUTHORITY

CHULA VISTA · 191,282 residents

Top concern: Haloacetic acids (HAA9) significantly above health guideline

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D
59/100

OLIVENHAIN MWD

ENCINITAS · 86,458 residents

Top concern: Arsenic significantly above health guideline

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F
53/100

VALLECITOS WD

SAN MARCOS · 113,500 residents

Top concern: PFAS contamination

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F
53/100

CARLSBAD MWD

CARLSBAD · 95,158 residents

Top concern: PFAS contamination

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F
53/100

OCEANSIDE, CITY OF

OCEANSIDE · 171,483 residents

Top concern: PFAS contamination

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F
52/100

CAL-AM WATER CORONADO

IMPERIAL BEACH · 106,000 residents

Top concern: PFAS contamination

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F
52/100

SAN DIEGO, CITY OF

SAN DIEGO · 1,385,379 residents

Top concern: PFAS contamination

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