Contra Costa County, California Water Systems

Contra Costa County, California

63 community water systems on record — 39 active, 24 inactive.

Every active community water system nationwide must produce a Consumer Confidence Report under the EPA's revised rule, effective for reports due July 1, 2027.

Data sourced from the EPA ECHO database (SDWA bulk download), last refreshed July 4, 2026. This is a record-keeping and public-information tool — it does not replace California’s official records. Always confirm current status with California before making decisions based on this information.

Community water systems in Contra Costa County, California

System name	City	Population served	Status
ANGLER S RANCH #3	BETHEL ISLAND	60	Active
ANGLERS SUBDIVISION 4	BETHEL ISLAND	99	Active
BEACON WEST	OAKLEY	45	Inactive
BELLA VISTA WATER SYS	MORAGA	93	Active
BETHEL ISLAND ESTATES	SACRAMENTO	200	Active
BETHEL ISLAND MHC	STOCKTON	185	Active
BETHEL ISLAND MUTUAL WATER CO	BETHEL ISLAND	123	Active
BIG OAK MOBILE HOME PARK WATER	OAKLEY	156	Active
BLACKHAWK WATER SERVICE	DANVILLE	33	Inactive
BLACKWOOD & ELY	LAFAYETTE	40	Inactive
BLUE GOOSE PROPERTY	WALNUT CREEK	1	Inactive
BOLLINGER CANYON	MORAGA	30	Inactive
BOUNDARY OAKS TENNIS CORP	WALNUT CREEK	25	Inactive
BRENTWOOD	BRENTWOOD	64,513	Active
CAMINO MOBILEHOME	OAKLEY	210	Active
CANYON WATER BROTHERS	YON, 94516	5	Inactive
CASA MEDANOS WATER SYSTEM	WALNUT CREEK	45	Active
CCWD/BRENTWOOD WTP	CONCORD	0	Active
CITY OF ANTIOCH	ANTIOCH	115,074	Active
CITY OF MARTINEZ	MARTINEZ	30,997	Active
CITY OF PITTSBURG	PITTSBURG	62,500	Active
CLAYTON PALMS WATER	CLAYTON	549	Active
COLONIA SANTA MARIA	BRENTWOOD	32	Active
CONTRA COSTA WATER DISTRICT	CONCORD	198,000	Active
DAVIS CAMP *CL 10/08	ANTIOCH	65	Inactive
DELTA MUTUAL WATER COMPANY	OAKLEY	333	Active
DIABLO WATER DISTRICT	OAKLEY	43,357	Active
DOUBLETREE RANCH WATER SYSTEM	LIVERMORE	66	Active
DUTCH SLOUGH WATER WORKS	OAKLEY	49	Active
EVERGREEN MOBILEHOME PARK	PARADISE	25	Inactive
FARRAR PARK PROPERTY OWNERS	BETHEL ISLAND RD	140	Active
GARY LARSEN	BRENTWOOD	25	Inactive
GOLDEN STATE WATER COMPANY - BAY POINT	RANCHO CORDOVA	23,731	Active
HERTZ WATER SYSTEM	OAKLEY	35	Inactive
JAMES A MCGRATH	ANTIOCH	25	Inactive
KNIGHTSEN COMMUNITY WATER SYSTEM	OAKLEY	73	Active
LEEMA ROAD WATER SYSTEM	DANVILLE	15	Inactive
LUNDBORG LANDING *CL 2/09	BETHEL ISLAND	420	Inactive
MAGALIA COUNTY WATER DISTRICT	CHICO	750	Inactive
MARINA MOBILE MANOR	FREMONT	75	Active
MILAN E WARD	CHICO	50	Inactive
MORAGA HEIGHTS MUTUAL WATER	CANYON	66	Active
MORRELL PROPERTY MGT	PITTSBURG	600	Inactive
MOTORCYCLE RECREATION	BRENTWOOD	25	Inactive
NORTHGATE MUTUAL WATER	CA, 94596	105	Inactive
OAKLEY MUTUAL WATER COMPANY	OAKLEY	170	Active
OROVILLE-WYANDOTTE IRRIG DIST	OROVILLE	100	Inactive
ORWOOD RESORT	BRENTWOOD	350	Active
OWID-COMMUNITY LINE	OROVILLE	0	Inactive
PLEASANTIMES MUTUAL WATER CO	BETHEL ISLAND	644	Active
RANDALL-BOLD WATER TREATMENT PLANT	CONCORD	1	Active
RIVERVIEW MOBILE HOME PARK	SACRAMENTO	126	Active
RIVERVIEW WATER ASSOCIATION	BETHEL ISLAND	230	Active
RUSSOS MOBILE PARK	BETHEL ISLAND	110	Active
SANDMOUND MUTUAL	BETHEL ISLAND	100	Active
SANDY POINT MOBILE HOME PARK	BRENTWOOD	67	Active
SANTIAGO ISLAND VILLAGE	SANTA ANA	0	Inactive
SMITH & HAGER WATER SYSTEM	FREMONT	25	Inactive
TOWN OF DISCOVERY BAY	DISCOVERY BAY	16,790	Active
WILCOX STATION RANCH	CANYON	31	Active
WILLOW MOBILE HOME PARK	MARTINEZ	481	Active
WILLOW PARK MARINA	OAKLEY	380	Active
WILLOW PASS MOBILE HOME *CL 1/07-INACTIV	CONCORD	140	Inactive