County Water Quality Report

Los Angeles County, California

40 public water systems serving 16,710,755 residents

Data sources: EPA SDWIS EPA ECHO EWG Tap Water Database Utility CCRs ⓘ How did we get these ratings?

County average grade

57/100

Utilities rated 40

Population served 16,710,755

Most recent test 2024

Top water quality concerns in Los Angeles County

Haloacetic acids (HAA5) significantly above health guidelinein 34 of 40 utilities
Haloacetic acids (HAA9) significantly above health guidelinein 22 of 40 utilities
PFAS contaminationin 20 of 40 utilities
Arsenic significantly above health guidelinein 19 of 40 utilities
Perfluorohexane sulfonate (PFHXS) significantly above health guidelinein 17 of 40 utilities

All utilities in Los Angeles County

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

67/100

GSWC - SOUTHWEST

HAWTHORNE · 277,740 residents

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

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67/100

ROWLAND WATER DISTRICT

ROWLAND HEIGHTS · 56,100 residents

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

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67/100

WALNUT VALLEY WATER DISTRICT

WALNUT · 100,941 residents

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

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67/100

Long Beach Water Authority

Long Beach · 467,000 residents

Top concern: PFAS contamination

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64/100

CALIFORNIA WATER SERVICE CO. - DOMINGUEZ

SAN JOSE · 143,996 residents

Top concern: Perfluorohexane sulfonate (PFHXS) significantly above health guideline

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64/100

GSWC - FLORENCE/GRAHAM

ANAHEIM · 63,500 residents

Top concern: Chromium (hexavalent) significantly above health guideline

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64/100

PALMDALE WATER DIST.

PALMDALE · 126,804 residents

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

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64/100

CALIFORNIA WATER SERVICE CO. - PALOS VER

SAN JOSE · 71,452 residents

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

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64/100

PASADENA WATER AND POWER

PASADENA · 164,344 residents

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

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64/100

CALIFORNIA WATER SERVICE CO. - HERM/REDO

SAN JOSE · 96,853 residents

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

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64/100

GSWC-SAN DIMAS

SAN DIMAS · 56,538 residents

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

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64/100

SANTA MONICA-CITY, WATER DIVISION

SANTA MONICA · 89,947 residents

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

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64/100

SUBURBAN WATER SYSTEMS-SAN JOSE

COVINA · 168,843 residents

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

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64/100

TORRANCE-CITY, WATER DEPT.

TORRANCE · 106,183 residents

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

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62/100

CITY OF ALHAMBRA

ALHAMBRA · 79,776 residents

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

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62/100

LONG BEACH UTILITIES DEPARTMENT

LONG BEACH · 466,772 residents

Top concern: Arsenic significantly above health guideline

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62/100

BURBANK-CITY, WATER DEPT.

BURBANK · 105,603 residents

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

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62/100

LAS VIRGENES MWD

CALABASAS · 72,602 residents

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

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60/100

LAKEWOOD - CITY, WATER DEPT.

LAKEWOOD · 66,135 residents

Top concern: Arsenic significantly above health guideline

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59/100

LOS ANGELES-CITY, DEPT. OF WATER & POWER

LOS ANGELES · 7,751,132 residents

Top concern: Arsenic significantly above health guideline

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56/100

GLENDALE-CITY, WATER DEPT.

GLENDALE · 188,784 residents

Top concern: PFAS contamination

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56/100

INGLEWOOD- CITY, WATER DEPT.

INGLEWOOD · 80,824 residents

Top concern: PFAS contamination

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55/100

GSWC - BELL, BELL GARDENS

ANAHEIM · 54,877 residents

Top concern: PFAS contamination

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53/100

LOS ANGELES CWWD 40 REG 4 & 34 LANCASTER

ALHAMBRA · 208,129 residents

Top concern: PFAS contamination

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53/100

PARAMOUNT - CITY, WATER DEPT.

PARAMOUNT · 55,200 residents

Top concern: PFAS contamination

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52/100

POMONA - CITY, WATER DEPT.

POMONA · 151,713 residents

Top concern: PFAS contamination

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50/100

CALIFORNIA WATER SERVICE CO. - ELA

SAN JOSE · 152,474 residents

Top concern: PFAS contamination

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48/100

Los Angeles Water Utilities

Los Angeles · 3,979,000 residents

Top concern: Lead detected in source water

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48/100

VALLEY COUNTY WATER DIST.

BALDWIN PARK · 68,871 residents

Top concern: PFAS contamination

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48/100

DOWNEY - CITY, WATER DEPT.

DOWNEY · 110,556 residents

Top concern: PFAS contamination

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48/100

SAN GABRIEL VALLEY WATER CO.-EL MONTE

EL MONTE · 248,000 residents

Top concern: PFAS contamination

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48/100

MONTEREY PARK-CITY, WATER DEPT.

MONTEREY PARK · 62,183 residents

Top concern: PFAS contamination

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48/100

SUBURBAN WATER SYSTEMS-WHITTIER

COVINA · 66,045 residents

Top concern: PFAS contamination

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47/100

AZUSA LIGHT AND WATER

AZUSA · 110,044 residents

Top concern: PFAS contamination

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47/100

COMPTON-CITY, WATER DEPT.

COMPTON · 74,877 residents

Top concern: PFAS contamination

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47/100

SUBURBAN WATER SYSTEMS-LA MIRADA

COVINA · 56,793 residents

Top concern: PFAS contamination

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47/100

LYNWOOD-CITY, WATER DEPT.

LYNWOOD · 66,967 residents

Top concern: PFAS contamination

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47/100

SOUTH GATE-CITY, WATER DEPT.

SOUTH GATE · 76,443 residents

Top concern: PFAS contamination

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47/100

LIBERTY UTILITIES - BELLFLOWER-NORWALK

DOWNEY · 72,624 residents

Top concern: PFAS contamination

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47/100

SANTA CLARITA VALLEY WATER AGENCY

NEWHALL · 294,090 residents

Top concern: PFAS contamination

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