Alameda County, California — public water systems

27 active public water systems serve Alameda County, reporting 2.2M people served.

Dataset updated July 2026 . Source: EPA SDWIS/ECHO, refreshed quarterly.

Active systems

Population served

2.2M

Community systems

Groundwater share

44.4%

Water systems in Alameda County

Active public water systems in Alameda County, California
#	Water system	County	Population served	Type	Source
1	East Bay MUD	Alameda	1,442,800	Community	Surface water
2	Alameda County Water District	Alameda	344,000	Community	Surface water
3	City of Hayward	Alameda	162,954	Community	Purchased surface water
4	Dublin San Ramon Services District	Alameda	98,776	Community	Purchased surface water
5	City of Pleasanton	Alameda	76,689	Community	Purchased surface water
6	California Water Service - Livermore	Alameda	60,414	Community	Purchased surface water
7	City of Livermore	Alameda	38,892	Community	Purchased surface water
8	Lawrence Livermore National Lab Site 200	Alameda	10,870	Non-transient non-community	Purchased surface water
9	Ebrpd - Del Valle Regional Park	Alameda	9,024	Transient non-community	Surface water
10	Chp - Mission Grade Scales	Alameda	1,800	Transient non-community	Groundwater
11	Alameda Point	Alameda	1,400	Community	Purchased surface water
12	Castlewood Domestic Water System	Alameda	524	Community	Purchased groundwater
13	Trailer Haven Mobile Home Park	Alameda	459	Community	Purchased surface water
14	Town of Sunol - Sfpuc	Alameda	281	Community	Purchased surface water
15	Sunol Super Stop	Alameda	155	Transient non-community	Groundwater
16	Ebrpd - Sunol Regional Wilderness	Alameda	91	Transient non-community	Groundwater
17	Usbr-Sldmwa - Cvp Jones Pumping Plant	Alameda	90	Non-transient non-community	Surface water
18	Alameda County Fairgrounds	Alameda	82	Non-transient non-community	Groundwater
19	Purple Orchid Resort Spa	Alameda	52	Transient non-community	Groundwater
20	Mountain House School	Alameda	50	Non-transient non-community	Purchased surface water
21	Norris Canyon Property Owners Assn	Alameda	50	Community	Groundwater
22	Ebrpd - Piedmont Stables	Alameda	45	Transient non-community	Groundwater
23	Zone 7 Water Agency	Alameda	40	Community	Surface water
24	Rancho Los Mochos-Bsa Camp	Alameda	38	Transient non-community	Groundwater
25	Rivers End Marina	Alameda	32	Transient non-community	Groundwater
26	Mountain House Bar	Alameda	25	Transient non-community	Groundwater
27	Sfpuc-Pleasanton Wells	Alameda	1	Community	Groundwater