County Water Quality Report

Stanislaus County, California

4 public water systems serving 559,966 residents

Data sources: EPA SDWIS EPA ECHO EWG Tap Water Database Utility CCRs ⓘ How did we get these ratings?
County average grade
F
52/100
Utilities rated 4
Population served 559,966
Most recent test 2024

Top water quality concerns in Stanislaus County

  • Arsenic significantly above health guidelinein 4 of 4 utilities
  • Haloacetic acids (HAA5) significantly above health guidelinein 3 of 4 utilities
  • PFAS contaminationin 2 of 4 utilities
  • Chromium (hexavalent) significantly above health guidelinein 2 of 4 utilities
  • Perfluorohexane sulfonate (PFHXS) significantly above health guidelinein 1 of 4 utilities

All utilities in Stanislaus County

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

D
57/100

TURLOCK, CITY OF

TURLOCK · 72,682 residents

Top concern: Arsenic significantly above health guideline

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D
57/100

CERES, CITY OF

CERES · 54,513 residents

Top concern: Arsenic significantly above health guideline

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F
49/100

City of Modesto Water Department

Modesto · 214,000 residents

Top concern: PFAS contamination

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F
47/100

MODESTO, CITY OF

MODESTO · 218,771 residents

Top concern: PFAS contamination

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