Based on EPA UCMR5 monitoring data, EPA SDWIS federal violations records, and EWG Tap Water Database published findings.
Silicon Valley tech/industrial legacy affects groundwater. Imports from SFPUC (Hetch Hetchy) are cleaner.
Water source: Surface water + groundwater blend (Santa Clara Valley)
Water utility: San Jose Water Company
Detected at approximately 2.8 ppt total per available EPA data — below the new EPA MCL of 4 ppt but above levels many health researchers consider optimal for lifetime daily consumption. Reverse osmosis filtration is recommended.
The EPA's new maximum contaminant level (MCL) for PFAS is 4 ppt, effective 2026. PFAS compounds have been linked to cancer, thyroid disease, immune disruption, and developmental issues at chronic exposure levels per peer-reviewed research.
The following contaminants have been detected or are associated with elevated risk in this water system, per available EPA and EWG published data:
These detections are drawn from EPA SDWIS federal violations database and EWG Tap Water Database records. EWG health guidelines are stricter than EPA legal limits and reflect long-term exposure risk.
No health-based EPA violations recorded in the past 5 years at this utility. Note: EPA violations reflect legal compliance thresholds, which are less protective than the EWG health guidelines used in HAVEN's scoring model.
Reverse osmosis filtration is recommended — AquaTru Carafe ($149) or APEC ROES-50 under-sink RO ($250). RO removes 99%+ PFAS, lead, nitrates, arsenic, chromium, and disinfection byproducts in a single system.
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