EPA EXPORT · 13 SEP 2026FEDERAL COMPLIANCE RECORDS · NOT A HOME WATER TEST
TAP WATERLEDGERPublic system compliance records

STATE / TERRITORY LEDGER

California drinking water system records

EPA compliance fields for active community water systems reporting at least 2,500 people served.

Systems754active CWS · pop. 2,500+
Population served39,518,878reported total; may overlap
Current violation flag13.5%102 systems
Serious-violator flag0.8%6 systems

01 / LARGEST SYSTEMS

Community water systems in California

Population served is a system-reported service figure. It is not a count of unique state residents.

Water systemPopulation servedPrimary sourceCurrent export status
Los Angeles-City, Dept. Of Water & PowerCA19100673,875,566Surface waterNo current violation flagged
East Bay MudCA01100051,442,800Surface waterNo current violation flagged
San Diego, City OfCA37100201,385,379Surface waterNo current violation flagged
San Jose WaterCA43100111,039,920Surface waterNo current violation flagged
Sfpuc City Distribution DivisionCA3810011848,019Surface water purchasedNo current violation flagged
Eastern Municipal WdCA3310009666,581Surface water purchasedNo current violation flagged
City Of FresnoCA1010007545,716Surface waterNo current violation flagged
City Of Sacramento MainCA3410020527,979Surface waterNo current violation flagged
Long Beach Utilities DepartmentCA1910065466,772Surface water purchasedNo current violation flagged
Irvine Ranch Water DistrictCA3010092444,800Surface waterNo current violation flagged
City Of AnaheimCA3010001348,593Surface waterNo current violation flagged
Alameda County Water DistrictCA0110001344,000Surface waterNo current violation flagged
City Of Santa AnaCA3010038310,539Surface water purchasedNo current violation flagged
Riverside, City OfCA3310031298,398Groundwater under influence of surface waterNo current violation flagged
Santa Clarita Valley Water AgencyCA1910240294,090Surface waterNo current violation flagged
Gswc - SouthwestCA1910155277,740Surface water purchasedNo current violation flagged
Helix Water DistrictCA3710010277,668Surface waterNo current violation flagged
Coachella Vwd: Cove CommunityCA3310001270,000Ground waterNo current violation flagged
Cws - BakersfieldCA1510003267,881Surface waterNo current violation flagged
San Gabriel Valley Water Co.-El MonteCA1910039248,000Ground waterNo current violation flagged
Otay Water DistrictCA3710034238,008Surface water purchasedNo current violation flagged
San Gabriel Valley Wc - FontanaCA3610041237,700Surface waterNo current violation flagged
Modesto, City OfCA5010010218,771Surface water purchasedNo current violation flagged
San Bernardino CityCA3610039214,665Ground waterNo current violation flagged
Cucamonga Valley Water DistrictCA3610018211,069Surface waterNo current violation flagged
Los Angeles Cwwd 40 Reg 4 & 34 LancasterCA1910070208,129Surface water purchasedNo current violation flagged
City Of Huntington BeachCA3010053201,000Surface water purchasedNo current violation flagged
Oxnard Water DeptCA5610007200,232Surface water purchasedNo current violation flagged
Contra Costa Water DistrictCA0710003198,000Surface waterNo current violation flagged
Sacramento Suburban Water DistrictCA3410001194,444Surface water purchasedNo current violation flagged
City Of StocktonCA3910012191,302Surface waterNo current violation flagged
Sweetwater AuthorityCA3710025191,282Surface waterNo current violation flagged
Glendale-City, Water Dept.CA1910043188,784Surface water purchasedNo current violation flagged
Marin Municipal Water DistrictCA2110002186,895Surface waterNo current violation flagged
Ontario Municipal Utilities CompanyCA3610034185,010Surface water purchasedNo current violation flagged
Scwa - Laguna/VineyardCA3410029184,896Surface waterCurrent health-based flag
California Water Service - StocktonCA3910001176,266Surface water purchasedNo current violation flagged
Santa Rosa, City OfCA4910009175,396Ground waterNo current violation flagged
City Of Garden GroveCA3010062174,226Surface water purchasedNo current violation flagged
Oceanside, City OfCA3710014171,483Surface water purchasedNo current violation flagged
Moulton Niguel Water DistrictCA3010073170,236Surface water purchasedNo current violation flagged
Elsinore Valley MwdCA3310012169,455Surface waterNo current violation flagged
Suburban Water Systems-San JoseCA1910205168,843Surface water purchasedNo current violation flagged
Corona, City OfCA3310037168,575Surface water purchasedNo current violation flagged
Santa Margarita Water DistrictCA3010101168,289Surface water purchasedNo current violation flagged
Pasadena Water And PowerCA1910124164,344Surface water purchasedNo current violation flagged
City Of HaywardCA0110006162,954Surface water purchasedNo current violation flagged
Bakersfield, City OfCA1510031160,144Surface water purchasedNo current violation flagged
City Of SunnyvaleCA4310014157,566Surface water purchasedNo current violation flagged
City Of RosevilleCA3110008155,612Surface waterNo current violation flagged
California Water Service Co. - ElaCA1910036152,474Surface water purchasedNo current violation flagged
Pomona - City, Water Dept.CA1910126151,713Surface waterNo current violation flagged
Cws - VisaliaCA5410016148,496Ground waterNo current violation flagged
Rancho California Water DistrictCA3310038146,147Surface water purchasedNo current violation flagged
California Water Service Co. - DominguezCA1910033143,996Surface water purchasedNo current violation flagged
City Of FullertonCA3010010139,461Surface water purchasedNo current violation flagged
Escondido, City OfCA3710006137,044Surface waterNo current violation flagged
Victorville Water DistrictCA3610052135,983Surface water purchasedNo current violation flagged
Jurupa Community SdCA3310021135,093Surface water purchasedNo current violation flagged
Vista Irrigation DistrictCA3710027132,430Surface waterNo current violation flagged
El Dorado Id - MainCA0910001132,171Surface waterNo current violation flagged
City Of Santa ClaraCA4310012130,746Surface water purchasedNo current violation flagged
City Of ClovisCA1010003130,130Surface waterNo current violation flagged
Palmdale Water Dist.CA1910102126,804Surface waterNo current violation flagged
Cwsc SalinasCA2710010123,679Ground waterNo current violation flagged
City Of VallejoCA4810007121,420Surface waterNo current violation flagged
City Of OrangeCA3010027120,770Surface water purchasedNo current violation flagged
City Of FairfieldCA4810003120,377Surface waterCurrent health-based flag
City Of AntiochCA0710001115,074Surface waterNo current violation flagged
Cal-Water Service Co.-ChicoCA0410002114,925Ground waterNo current violation flagged
Golden State Wc - West Orange CountyCA3010022114,379Surface water purchasedNo current violation flagged
Vallecitos WdCA3710002113,500Surface water purchasedCurrent monitoring/reporting flag
Ventura Water DepartmentCA5610017113,500Surface waterNo current violation flagged
Downey - City, Water Dept.CA1910034110,556Ground waterNo current violation flagged
Great Oaks Wc IncCA4310022110,088Ground waterNo current violation flagged
Azusa Light And WaterCA1910007110,044Surface waterNo current violation flagged
Mesa Water DistrictCA3010004110,000Surface water purchasedNo current violation flagged
San Bernardino Valley WdCA3610019109,608Ground waterNo current violation flagged
City Of Santa Maria Utilities DepartmentCA4210011109,477Surface water purchasedNo current violation flagged
East Valley Water DistrictCA3610064108,629Surface waterNo current violation flagged
Torrance-City, Water Dept.CA1910213106,183Surface water purchasedNo current violation flagged
Cal-Am Water CoronadoCA3710001106,000Surface water purchasedNo current violation flagged
Burbank-City, Water Dept.CA1910179105,603Surface water purchasedNo current violation flagged
City Of Daly CityCA4110013104,901Surface water purchasedNo current violation flagged
West Valley Water DistrictCA3610004104,498Surface waterNo current violation flagged
California Water Service - San MateoCA4110008102,348Surface water purchasedNo current violation flagged
City Of San Jose - Evg/Edv/CoyCA4310020101,265Surface water purchasedNo current violation flagged
Walnut Valley Water DistrictCA1910234100,941Surface water purchasedNo current violation flagged
Hesperia WdCA3610024100,744Ground waterNo current violation flagged
South Tahoe Pud - MainCA0910002100,000Ground waterNo current violation flagged
City Of VacavilleCA481000899,650Surface waterNo current violation flagged
City Of Santa Barbara Water DepartmentCA421001099,323Surface waterNo current violation flagged
Dublin San Ramon Services DistrictCA011000998,776Surface water purchasedNo current violation flagged
California Water Service Co. - Herm/RedoCA191013496,853Surface water purchasedNo current violation flagged
Tracy, City OfCA391001196,609Surface waterNo current violation flagged
Carlsbad MwdCA371000595,158Surface water purchasedNo current violation flagged
Ventura Wwd No. 8 - Simi ValleyCA561002394,738Surface water purchasedNo current violation flagged
Santa Cruz Water DepartmentCA441001094,626Surface waterNo current violation flagged
Padre Dam MwdCA371003793,980Surface water purchasedNo current violation flagged
City Of MercedCA241000993,692Ground waterNo current violation flagged

Showing the 100 largest systems by reported population served.

02 / CITY REPORTS

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03 / COUNTY REPORTS

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