County Water Quality Report

Cook County, Illinois

14 public water systems serving 6,228,834 residents

Data sources: EPA SDWIS EPA ECHO EWG Tap Water Database Utility CCRs ⓘ How did we get these ratings?
County average grade
D
64/100
Utilities rated 14
Population served 6,228,834
Most recent test 2024
🇪🇺 Would fail EU standards 1 of 14

Top water quality concerns in Cook County

  • Haloacetic acids (HAA9) significantly above health guidelinein 13 of 14 utilities
  • Total trihalomethanes (TTHMs) significantly above health guidelinein 13 of 14 utilities
  • Bromodichloromethane significantly above health guidelinein 11 of 14 utilities
  • PFAS contaminationin 2 of 14 utilities
  • Haloacetic acids (HAA5) significantly above health guidelinein 2 of 14 utilities

All utilities in Cook County

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

C
67/100

BERWYN

BERWYN · 57,250 residents

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

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C
67/100

CICERO

CICERO · 83,000 residents

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

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C
67/100

DES PLAINES

DES PLAINES · 60,675 residents

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

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C
67/100

OAK LAWN

OAK LAWN · 58,362 residents

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

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C
67/100

OAK PARK

OAK PARK · 54,583 residents

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

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C
67/100

PALATINE

PALATINE · 70,875 residents

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

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C
67/100

ARLINGTON HEIGHTS

ARLINGTON HEIGHTS · 73,320 residents

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

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C
67/100

SCHAUMBURG

SCHAUMBURG · 75,750 residents

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

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C
67/100

TINLEY PARK

TINLEY PARK · 56,703 residents

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

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C
67/100

CHICAGO

CHICAGO · 2,746,388 residents

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

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C
65/100

ORLAND PARK

ORLAND PARK · 58,020 residents

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

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D
56/100

Chicago Water Authority

Chicago · 2,693,000 residents

Top concern: Lead detected in source water

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D
55/100

EVANSTON

EVANSTON · 74,486 residents

Top concern: PFAS contamination

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D
55/100

SKOKIE

SKOKIE · 66,422 residents

Top concern: PFAS contamination

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