Tapcensus

Water quality for ZIP code 94588

ZIP 94588 covers Pleasanton, Hayward, and Sunol in Alameda County, California, one of 49 ZIP codes in the county. 27 active public water systems serve the county; 4 had an EPA violation in the past three years.

Most likely your provider

Zone 7 Water Agency CA0110010 · Community water system · Surface water
Serves 40 people Rules violated, past 3 years 0 Last sanitary survey Dec 17, 2025 Distance 13.0 mi

Your location is within the outer bounds of this system's EPA service area.

Other community water systems in Alameda County

13 systems, nearest first
SystemServesStatusRules violated, 3 yrDistance
Dublin San Ramon Services District
98,776 0 4.8 mi
City of Livermore
Livermore
38,892 0 8.6 mi
City of Pleasanton
Pleasanton
76,689 0 9.2 mi
California Water Service Livermore
60,414 0 9.5 mi
Norris Canyon Property Owners Assn
50 1 10.0 mi
Sfpuc-Pleasanton Wells
1 0 11.2 mi
Town of Sunol Sfpuc
281 0 13.4 mi
City of Hayward
Hayward
162,954 0 15.7 mi
Trailer Haven Mobile Home Park
459 0 16.5 mi
East Bay MUD
1,468,000 0 18.4 mi
Alameda County Water District
344,000 0 19.7 mi
Alameda Point
600 0 24.6 mi
Castlewood Domestic Water System
524 1 29.4 mi
Non-community systems in Alameda County (13: schools, campgrounds, workplaces, restaurants)

These systems serve places you visit rather than homes.

SystemServesStatusRules violated, 3 yrUnresolved
Alameda County Fairgrounds
82 1 1
Lawrence Livermore National Lab Site 200
Livermore
10,735 0 0
Purple Orchid Resort Spa
Livermore
52 0 0
Usbr-Sldmwa Cvp Jones Pumping Plant
90 0 0
Sunol Super Stop
155 0 0
Mountain House School
50 0 0
Ebrpd del Valle Regional Park
9,024 0 0
Mountain House Bar
25 0 0
Chp Mission Grade Scales
Pleasanton
1,800 1 0
Ebrpd Piedmont Stables
45 0 0
Rivers End Marina
32 0 0
Ebrpd Sunol Regional Wilderness
91 0 0
Rancho los Mochos-Bsa Camp
38 0 0
About this data

Water systems are matched to Alameda County, the county this ZIP code lies in, nearest to the ZIP code's centre first. Your exact provider depends on your address and connection; the largest community water system in a county is usually the city or town utility. Distances are measured to the centre of the service area EPA publishes for the system.

ZIP code areas and town boundaries come from the U.S. Census Bureau's 2020 ZCTA files.

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.