San Jose Tap Water
Water provider: Valley Water + San Jose Water Company (San Jose, CA)
Our recommendation
Premium filter strongly recommended
Your water has contaminants that require stronger filtration (heavy metals, PFAS, or limits exceeded). Reverse osmosis is the recommended tier.
See recommended water filters →What is in the water
Chromium-6 (hexavalent chromium)
DetectedIndustrial contaminant. Known human carcinogen. Unregulated at the federal level in the US.
EWG lists chromium-6 among detected contaminants for San Jose area supplies.
Nitrates
DetectedCommon in agricultural areas from fertiliser runoff. Particularly dangerous for infants.
Groundwater blending in Santa Clara Valley keeps nitrate monitoring active.
Trihalomethanes (THMs)
DetectedDisinfection byproducts formed when chlorine reacts with organic matter. Long-term exposure linked to cancer risk.
Disinfection byproducts are reported in treated distribution water.
PFAS (forever chemicals)
Not reportedPer- and polyfluoroalkyl substances. Bioaccumulate in the body. Linked to cancer, immune effects, and hormone disruption.
Verify the current EWG PFAS indicator on the utility page. Automation could not retrieve the live indicator behind Cloudflare.
Source
Data from the EWG Tap Water Database, Valley Water + San Jose Water Company (2024). Last reviewed 2026-05-25.
One combined entry for San Jose city coverage. Local service is a mix of Valley Water wholesale supply and San Jose Water retail service.
Note: Contaminant levels vary by address (older plumbing can leach lead even when the source water does not), sampling location, and time of year. The figures above reflect utility-wide averages from the most recent public report. If you have specific health concerns, request a full report from your utility or test your own tap water.