Water quality for ZIP code 94304
ZIP 94304 covers Palo Alto, Stanford, and Los Altos Hills in Santa Clara County, California, one of 58 ZIP codes in the county. 119 active public water systems serve the county; 41 had an EPA violation in the past three years.
Most likely your provider
Your location is within the outer bounds of this system's EPA service area.
Other community water systems in Santa Clara County
72 systems, nearest firstNon-community systems in Santa Clara County (46: schools, campgrounds, workplaces, restaurants)
These systems serve places you visit rather than homes.
About this data
Water systems are matched to Santa Clara 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 or, for systems without one, to the centre of the first town EPA lists the system as serving, from Census Bureau place files.
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. Retrieved from ECHO on Oct 11, 2026.