California
Alameda County drinking water quality
27 active public water systems serve 2,273,899 people in Alameda County. 23 are compliant, 4 had at least one EPA violation in the past three years, 0 are designated serious violators, and 2 carry a health flag.
Needs attention
Community water systems
14 systems, largest first| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
East Bay MUD |
1,468,000 | 0 | 0 | |
|
Alameda County Water District |
344,000 | 0 | 0 | |
|
City of Hayward Hayward |
162,954 | 0 | 0 | |
|
Dublin San Ramon Services District |
98,776 | 0 | 0 | |
|
City of Pleasanton Pleasanton |
76,689 | 0 | 0 | |
|
California Water Service Livermore |
60,414 | 0 | 0 | |
|
City of Livermore Livermore |
38,892 | 0 | 0 | |
|
Alameda Point |
600 | 0 | 0 | |
|
Castlewood Domestic Water System |
524 | 1 | 0 | |
|
Trailer Haven Mobile Home Park |
459 | 0 | 0 | |
|
Town of Sunol Sfpuc |
281 | 0 | 0 | |
|
Norris Canyon Property Owners Assn |
50 | 1 | 1 | |
|
Zone 7 Water Agency |
40 | 0 | 0 | |
|
Sfpuc-Pleasanton Wells |
1 | 0 | 0 |
Non-community systems (13: schools, campgrounds, workplaces, restaurants)
These systems serve places people visit rather than homes.
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Lawrence Livermore National Lab Site 200 Livermore |
10,735 | 0 | 0 | |
|
Ebrpd del Valle Regional Park |
9,024 | 0 | 0 | |
|
Chp Mission Grade Scales Pleasanton |
1,800 | 1 | 0 | |
|
Sunol Super Stop |
155 | 0 | 0 | |
|
Ebrpd Sunol Regional Wilderness |
91 | 0 | 0 | |
|
Usbr-Sldmwa Cvp Jones Pumping Plant |
90 | 0 | 0 | |
|
Alameda County Fairgrounds |
82 | 1 | 1 | |
|
Purple Orchid Resort Spa Livermore |
52 | 0 | 0 | |
|
Mountain House School |
50 | 0 | 0 | |
|
Ebrpd Piedmont Stables |
45 | 0 | 0 | |
|
Rancho los Mochos-Bsa Camp |
38 | 0 | 0 | |
|
Rivers End Marina |
32 | 0 | 0 | |
|
Mountain House Bar |
25 | 0 | 0 |
Inactive systems (23, no longer operating or reporting)
Kept for the record and excluded from the county totals above. Browse inactive systems.
About this data
Totals cover active systems. Systems serving more than one county are counted in each county. EPA counts the rules a system was in violation of, not the individual violations; one rule can carry several.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The California records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.