California Tap Water Quality

Explore tap water quality data for counties across California. View water system reports, track violations, monitor drinking water safety, and check fluoridation status in your community.

Counties

294

With water systems

Population

39,745,880

Served by water systems

Water Systems

2,834

Total water systems

Violators

3

Systems with serious violations

Searching by your address yields the most accurate results. Searching by town or water system may not show all systems due to how the EPA categorizes data. Some towns may be listed under counties, and water system boundaries don't always align with town boundaries.

Filter Results

California Counties

Adelanto

Population: 39,930

Water Systems: 1

Alameda

Population: 1,948,861

Water Systems: 12

Alhambra

Population: 83,750

Water Systems: 1

Alpine

Population: 8,621

Water Systems: 5

Alturas

Population: 2,715

Water Systems: 1

Amador

Population: 24,578

Water Systems: 18

American Canyon

Population: 20,990

Water Systems: 1

Anaheim

Population: 337,159

Water Systems: 1

Anderson

Population: 11,147

Water Systems: 1

Angels Camp

Population: 3,836

Water Systems: 1

Antioch

Population: 115,074

Water Systems: 1

Arcadia

Population: 45,764

Water Systems: 1

Arcata

Population: 21,193

Water Systems: 1

Atwater

Population: 29,479

Water Systems: 1

Avenal

Population: 13,696

Water Systems: 1

Bakersfield

Population: 158,260

Water Systems: 1

Banning

Population: 30,683

Water Systems: 1

Bell Gardens

Population: 11,305

Water Systems: 1

Benicia

Population: 27,131

Water Systems: 1

Beverly Hills

Population: 40,856

Water Systems: 1

Big Bear

Population: 12,738

Water Systems: 1

Biggs

Population: 2,060

Water Systems: 1

Bishop

Population: 3,819

Water Systems: 2

Blue Lake

Population: 1,245

Water Systems: 1

Blythe

Population: 9,874

Water Systems: 1

Brawley

Population: 26,928

Water Systems: 1

Brea

Population: 47,589

Water Systems: 1

Brentwood

Population: 64,513

Water Systems: 1

Brisbane

Population: 3,390

Water Systems: 1

Buena Park

Population: 81,998

Water Systems: 1

Burbank

Population: 104,535

Water Systems: 1

Burlingame

Population: 31,447

Water Systems: 1

Butte

Population: 185,298

Water Systems: 41

Calaveras

Population: 46,672

Water Systems: 18

Calexico

Population: 40,357

Water Systems: 1

California

Population: 14,198

Water Systems: 1

Calistoga

Population: 5,610

Water Systems: 1

Ceres

Population: 54,513

Water Systems: 1

Cerritos

Population: 47,475

Water Systems: 1

Chino

Population: 86,435

Water Systems: 1

Chino Hills

Population: 77,058

Water Systems: 1

Chowchilla

Population: 13,576

Water Systems: 1

Cloverdale

Population: 10,557

Water Systems: 1

Clovis

Population: 128,411

Water Systems: 1

Coachella

Population: 42,835

Water Systems: 1

Coalinga

Population: 17,277

Water Systems: 1

Colton

Population: 46,525

Water Systems: 1

Colusa

Population: 11,749

Water Systems: 8

Compton

Population: 74,877

Water Systems: 1

Contra Costa

Population: 287,188

Water Systems: 35

Corcoran

Population: 21,835

Water Systems: 1

Corning

Population: 8,244

Water Systems: 1

Corona

Population: 168,575

Water Systems: 1

Cotati

Population: 7,360

Water Systems: 1

Covina

Population: 33,300

Water Systems: 1

Crescent

Population: 17,420

Water Systems: 2

Cupertino

Population: 16,336

Water Systems: 1

Daly City

Population: 108,599

Water Systems: 1

Davis

Population: 67,217

Water Systems: 1

Del Mar

Population: 3,929

Water Systems: 1

Del Norte

Population: 7,780

Water Systems: 13

Delano

Population: 51,428

Water Systems: 1

Dinuba

Population: 26,955

Water Systems: 1

Dorris

Population: 887

Water Systems: 1

Dos Palos

Population: 7,452

Water Systems: 1

Downey

Population: 109,934

Water Systems: 1

Dunsmuir

Population: 1,707

Water Systems: 1

East Palo Alto

Population: 29,519

Water Systems: 1

El Centro

Population: 44,158

Water Systems: 1

El Dorado

Population: 278,231

Water Systems: 17

El Monte

Population: 22,968

Water Systems: 1

El Segundo

Population: 16,898

Water Systems: 1

Escalon

Population: 7,264

Water Systems: 1

Escondido

Population: 137,941

Water Systems: 1

Etna

Population: 720

Water Systems: 1

Eureka

Population: 27,078

Water Systems: 1

Exeter

Population: 11,169

Water Systems: 1

Fairfield

Population: 120,377

Water Systems: 1

Farmersville

Population: 10,324

Water Systems: 1

Firebaugh

Population: 8,096

Water Systems: 1

Folsom

Population: 79,266

Water Systems: 2

Fort Bragg

Population: 6,983

Water Systems: 1

Fortuna

Population: 12,133

Water Systems: 1

Fountain Valley

Population: 56,747

Water Systems: 1

Fowler

Population: 7,100

Water Systems: 1

Fresno

Population: 691,222

Water Systems: 90

Fullerton

Population: 141,874

Water Systems: 1

Galt

Population: 26,536

Water Systems: 1

Garden Grove

Population: 174,226

Water Systems: 1

Gilroy

Population: 58,108

Water Systems: 1

Glendale

Population: 188,784

Water Systems: 1

Glendora

Population: 52,558

Water Systems: 1

Glenn

Population: 8,904

Water Systems: 11

Gonzales

Population: 8,611

Water Systems: 2

Grass Valley

Population: 4,947

Water Systems: 1

Greenfield

Population: 18,967

Water Systems: 1

Gridley

Population: 7,444

Water Systems: 1

Gustine

Population: 5,945

Water Systems: 1

Hamilton

Population: 1,779

Water Systems: 1

Hanford

Population: 62,127

Water Systems: 1

Hawthorne

Population: 44,729

Water Systems: 1

Hayward

Population: 162,954

Water Systems: 1

Healdsburg

Population: 10,914

Water Systems: 1

Hemet

Population: 33,828

Water Systems: 1

Hollister

Population: 25,941

Water Systems: 1

Holtville

Population: 6,355

Water Systems: 1

Hughson

Population: 7,481

Water Systems: 1

Humboldt

Population: 56,530

Water Systems: 39

Huntington Beach

Population: 201,000

Water Systems: 1

Huntington Park

Population: 15,275

Water Systems: 1

Huron

Population: 9,306

Water Systems: 1

Imperial

Population: 51,860

Water Systems: 24

Inglewood

Population: 80,824

Water Systems: 1

Inyo

Population: 12,284

Water Systems: 44

Jackson

Population: 12,246

Water Systems: 2

Kerman

Population: 16,995

Water Systems: 1

Kern

Population: 620,721

Water Systems: 164

Kettleman

Population: 1,136

Water Systems: 1

Kings

Population: 22,762

Water Systems: 8

Kingsburg

Population: 12,380

Water Systems: 1

La Habra

Population: 63,118

Water Systems: 1

La Palma

Population: 15,948

Water Systems: 1

La Puente

Population: 6,125

Water Systems: 1

La Verne

Population: 32,206

Water Systems: 1

Lake

Population: 63,539

Water Systems: 43

Lakeport

Population: 4,762

Water Systems: 1

Lakewood

Population: 63,083

Water Systems: 1

Lassen

Population: 10,491

Water Systems: 14

Lathrop

Population: 35,080

Water Systems: 1

Lemoore

Population: 27,185

Water Systems: 1

Lincoln

Population: 51,252

Water Systems: 1

Lindsay

Population: 12,659

Water Systems: 1

Live Oak

Population: 9,285

Water Systems: 1

Livermore

Population: 38,892

Water Systems: 1

Livingston

Population: 14,894

Water Systems: 1

Lodi

Population: 68,272

Water Systems: 1

Loma Linda

Population: 25,129

Water Systems: 1

Lomita

Population: 20,256

Water Systems: 1

Lompoc

Population: 40,511

Water Systems: 2

Long Beach

Population: 458,222

Water Systems: 1

Los Angeles

Population: 7,338,078

Water Systems: 159

Los Banos

Population: 47,347

Water Systems: 1

Loyalton

Population: 983

Water Systems: 1

Lynwood

Population: 66,967

Water Systems: 1

Madera

Population: 118,858

Water Systems: 66

Manhattan Beach

Population: 33,673

Water Systems: 1

Manteca

Population: 84,928

Water Systems: 1

Marin

Population: 276,915

Water Systems: 15

Mariposa

Population: 6,887

Water Systems: 13

Martinez

Population: 30,997

Water Systems: 1

Mcfarland

Population: 15,506

Water Systems: 1

Mendocino

Population: 31,138

Water Systems: 38

Mendota

Population: 11,404

Water Systems: 1

Menlo Park

Population: 19,297

Water Systems: 1

Merced

Population: 133,338

Water Systems: 17

Midway

Population: 2,130

Water Systems: 2

Millbrae

Population: 22,795

Water Systems: 1

Milpitas

Population: 77,961

Water Systems: 1

Modesto

Population: 246,499

Water Systems: 10

Modoc

Population: 2,209

Water Systems: 4

Mono

Population: 18,816

Water Systems: 18

Monrovia

Population: 37,931

Water Systems: 1

Montague

Population: 1,264

Water Systems: 1

Montebello

Population: 11,453

Water Systems: 2

Monterey

Population: 337,606

Water Systems: 154

Monterey Park

Population: 62,183

Water Systems: 1

Morgan Hill

Population: 47,374

Water Systems: 1

Mount Shasta

Population: 3,642

Water Systems: 1

Mountain View

Population: 81,756

Water Systems: 1

Napa

Population: 95,651

Water Systems: 25

Needles

Population: 8,766

Water Systems: 1

Nevada

Population: 86,318

Water Systems: 19

Nevada City

Population: 3,148

Water Systems: 1

Newman

Population: 12,351

Water Systems: 1

Newport Beach

Population: 68,572

Water Systems: 1

Norco

Population: 25,037

Water Systems: 1

Norwalk

Population: 17,790

Water Systems: 1

Oakdale

Population: 23,235

Water Systems: 1

Oceanside

Population: 171,063

Water Systems: 1

Ontario

Population: 185,010

Water Systems: 1

Orange

Population: 1,385,300

Water Systems: 22

Orange Cove

Population: 9,525

Water Systems: 1

Orland

Population: 8,217

Water Systems: 1

Palo Alto

Population: 67,901

Water Systems: 1

Paramount

Population: 55,200

Water Systems: 1

Parlier

Population: 14,576

Water Systems: 1

Pasadena

Population: 161,162

Water Systems: 1

Patterson

Population: 23,304

Water Systems: 1

Perris

Population: 7,854

Water Systems: 1

Petaluma

Population: 60,665

Water Systems: 1

Pico Rivera

Population: 40,600

Water Systems: 1

Pittsburg

Population: 62,500

Water Systems: 1

Placer

Population: 200,686

Water Systems: 49

Pleasanton

Population: 76,689

Water Systems: 1

Plumas

Population: 22,909

Water Systems: 26

Plymouth

Population: 1,060

Water Systems: 1

Pomona

Population: 151,713

Water Systems: 1

Porterville

Population: 63,164

Water Systems: 1

Portola

Population: 2,100

Water Systems: 1

Poway

Population: 49,833

Water Systems: 1

Red Bluff

Population: 14,076

Water Systems: 1

Redding

Population: 87,741

Water Systems: 1

Redlands

Population: 78,025

Water Systems: 1

Redwood City

Population: 91,874

Water Systems: 1

Reedley

Population: 25,227

Water Systems: 1

Rialto

Population: 54,453

Water Systems: 1

Rio Dell

Population: 3,300

Water Systems: 1

Rio Vista

Population: 10,489

Water Systems: 1

Ripon

Population: 15,769

Water Systems: 1

Riverbank

Population: 24,834

Water Systems: 1

Riverside

Population: 2,211,976

Water Systems: 90

Rohnert Park

Population: 43,693

Water Systems: 1

Roseville

Population: 149,779

Water Systems: 1

Sacramento

Population: 1,482,709

Water Systems: 59

Saint Helena

Population: 5,386

Water Systems: 1

San Benito

Population: 32,862

Water Systems: 30

Serious Violator

San Bernardino

Population: 1,741,101

Water Systems: 137

San Bruno

Population: 44,745

Water Systems: 1

San Clemente

Population: 51,545

Water Systems: 1

San Diego

Population: 3,102,861

Water Systems: 76

San Fernando

Population: 23,946

Water Systems: 1

San Francisco

Population: 856,393

Water Systems: 5

San Jacinto

Population: 18,950

Water Systems: 1

San Joaquin

Population: 238,530

Water Systems: 89

San Jose

Population: 152,345

Water Systems: 3

San Juan Bautista

Population: 2,335

Water Systems: 1

San Juan Capistrano

Population: 38,347

Water Systems: 1

San Luis Obispo

Population: 267,646

Water Systems: 73

San Mateo

Population: 425,800

Water Systems: 27

San Simeon

Population: 160

Water Systems: 1

Sanger

Population: 26,241

Water Systems: 1

Santa Ana

Population: 308,189

Water Systems: 1

Santa Barbara

Population: 423,883

Water Systems: 61

Santa Clara

Population: 1,387,468

Water Systems: 57

Serious Violator

Santa Cruz

Population: 189,665

Water Systems: 51

Santa Fe Springs

Population: 57,244

Water Systems: 2

Santa Monica

Population: 89,947

Water Systems: 1

Santa Rosa

Population: 178,177

Water Systems: 1

Saugus

Population: 73

Water Systems: 2

Seal Beach

Population: 24,937

Water Systems: 1

Sebastopol

Population: 7,522

Water Systems: 1

Shafter

Population: 21,036

Water Systems: 1

Shasta

Population: 56,149

Water Systems: 59

Shasta Lake

Population: 10,657

Water Systems: 1

Sierra

Population: 2,547

Water Systems: 7

Sierra Madre

Population: 11,000

Water Systems: 1

Signal Hill

Population: 11,795

Water Systems: 1

Siskiyou

Population: 9,135

Water Systems: 25

Solano

Population: 78,890

Water Systems: 20

Soledad

Population: 18,648

Water Systems: 1

Serious Violator

Sonoma

Population: 125,850

Water Systems: 122

Sonora

Population: 1,744

Water Systems: 1

South Gate

Population: 76,443

Water Systems: 1

South Pasadena

Population: 25,329

Water Systems: 1

Stanislaus

Population: 22,194

Water Systems: 45

Stockton

Population: 196,239

Water Systems: 2

Sunnyvale

Population: 156,234

Water Systems: 1

Susanville

Population: 7,811

Water Systems: 1

Sutter

Population: 3,579

Water Systems: 6

Tahoe

Population: 7,409

Water Systems: 4

Tehachapi

Population: 9,094

Water Systems: 1

Tehama

Population: 13,271

Water Systems: 47

Torrance

Population: 106,183

Water Systems: 1

Tracy

Population: 94,538

Water Systems: 1

Trinidad

Population: 1,072

Water Systems: 1

Trinity

Population: 9,050

Water Systems: 17

Tulare

Population: 292,847

Water Systems: 88

Tulelake

Population: 856

Water Systems: 1

Tuolumne

Population: 59,171

Water Systems: 48

Turlock

Population: 72,682

Water Systems: 1

Tustin

Population: 66,600

Water Systems: 1

Ukiah

Population: 17,007

Water Systems: 2

Upland

Population: 78,376

Water Systems: 1

Vacaville

Population: 97,000

Water Systems: 1

Vallejo

Population: 124,220

Water Systems: 2

Ventura

Population: 908,268

Water Systems: 68

Vernon

Population: 28,112

Water Systems: 1

Wasco

Population: 22,652

Water Systems: 1

Watsonville

Population: 65,231

Water Systems: 1

Weed

Population: 2,662

Water Systems: 1

West Sacramento

Population: 53,355

Water Systems: 1

Westminster

Population: 95,256

Water Systems: 1

Westmorland

Population: 2,202

Water Systems: 1

Wheatland

Population: 3,712

Water Systems: 1

Whittier

Population: 49,954

Water Systems: 1

Williams

Population: 5,538

Water Systems: 1

Willits

Population: 6,175

Water Systems: 1

Winters

Population: 7,115

Water Systems: 1

Woodlake

Population: 7,950

Water Systems: 1

Woodland

Population: 61,462

Water Systems: 2

Serious Violator

Yolo

Population: 58,897

Water Systems: 13

Yreka

Population: 7,825

Water Systems: 1

Yuba

Population: 72,358

Water Systems: 21

Yuba City

Population: 70,256

Water Systems: 1