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Comprehensive Consumer Confidence Report for San Jose, California — served by San Jose Water Company (SJWC)
All contaminants are within EPA limits, but the score is held down by aging distribution infrastructure and past compliance/monitoring issues.
View detailed city report →Contaminant levels compared to EPA maximum limits (latest reported samples)
56% of EPA limit — the contaminant to watch here. A disinfection byproduct formed when chlorine reacts with organic matter in surface water.
44% of EPA limit. Typical of groundwater in an agricultural region; within the safe range.
31% of EPA limit. The other main chlorination byproduct, well within safe range.
28% of the action level at the tap. May leach from pipes and fixtures in older homes regardless of utility water quality.
Chromium (27% of limit) and fluoride (20% of limit) are both below EPA thresholds. California separately monitors hexavalent chromium (chromium-6).
San Jose Water Company blends local mountain surface water, imported treated supplies, and groundwater. Because much of the supply is chlorinated surface water, disinfection byproducts (TTHMs) are the most notable detected contaminant, though they remain within EPA limits.
Groundwater in the Santa Clara Valley is managed and recharged by Valley Water and monitored for nitrate and other contaminants before entering the distribution system.
San Jose's water is within EPA limits, but the one item worth reducing is trihalomethanes (TTHMs) — the chlorination byproduct sitting at 56% of the limit — plus any lead picked up from older home plumbing. A certified activated-carbon filter targets exactly these; a full reverse-osmosis system would be overkill given arsenic and nitrate are low here.
Waterdrop TSA Under-Sink Filter
NSF 42 activated-carbon under-sink · ~$55
Multi-stage carbon block reduces chlorine, disinfection byproducts and taste/odor — the right tool for San Jose's TTHM profile, with a quick under-sink install.
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NSF 53 certified to reduce lead and dissolved solids — the cheapest no-install option if your concern is lead from older plumbing rather than taste.
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Surface water is treated at SJWC's Montevina and Saratoga plants with coagulation, flocculation, sedimentation, and filtration to remove particles and turbidity.
Chlorine and chloramine are used to kill bacteria and viruses and maintain a residual throughout the distribution system.
Water chemistry is adjusted to reduce corrosivity, limiting lead and copper leaching from household plumbing and fixtures.
Imported water bought from Valley Water is treated at its Rinconada, Penitencia, and Santa Teresa plants — several use ozonation for taste, odor, and advanced oxidation.
Past monitoring & reporting violations — all resolved
Records show earlier chromium, fluoride, and mercury monitoring/reporting violations (2021–2025), each since marked resolved. These were administrative (monitoring or reporting) rather than health-based limit exceedances, but repeated compliance issues and aging infrastructure are why the overall score sits low.
View the complete Consumer Confidence Report on the San Jose Water Company website:
sjwater.com → Water Quality →Call San Jose Water Company Customer Service at (408) 279-7900 to request a printed copy of the annual water quality report.
Reports are mailed automatically to SJWC customers each year. You can also write to:
San Jose Water Company
110 W. Taylor Street, San Jose, CA 95110
San Jose's tap water is treated and tested by San Jose Water Company (SJWC) and meets EPA safety standards for every contaminant. The main thing to watch is disinfection byproducts (total trihalomethanes) at about 56% of the EPA limit. Levels are within legal limits, but many residents use a carbon filter to reduce disinfection byproducts and improve taste.
San Jose Water Company draws from three sources: local surface water from the Santa Cruz Mountains watershed (treated at the Montevina and Saratoga plants), treated surface water purchased wholesale from Valley Water via the State Water Project and Central Valley Project, and local groundwater from the Santa Clara and Coyote subbasins.
The most notable detected contaminants are disinfection byproducts — total trihalomethanes (TTHMs) and haloacetic acids (HAA5) — from chlorinating surface water. Nitrate appears in the groundwater supply, and lead may be present in homes with old plumbing. All measured levels are within EPA safety standards.
A certified activated-carbon filter is a sensible match here: it reduces the chlorine and disinfection byproducts (TTHMs) that are San Jose's main detected contaminant, and improves taste. If your concern is lead from older home plumbing, choose a filter certified to NSF 53 for lead reduction. A full reverse-osmosis system is more than most San Jose homes need.
San Jose Water Company publishes an annual Consumer Confidence Report online at sjwater.com. Reports are also mailed to customers each year and available by calling (408) 279-7900.