San Jose – California
San Jose, the third-largest city in California and tenth-largest in the United States, manages a complex water delivery system serving over 1 million residents. The city’s water infrastructure is operated by the San Jose Water Company, a subsidiary of SJW Group, which maintains approximately 1,500 miles of water mains, numerous pumping stations, and more than 100,000 service connections throughout Silicon Valley.
San Jose’s water comes from a diverse portfolio of sources including groundwater from the Santa Clara Valley’s aquifers, purchased surface water from the State Water Project and Pacheco Pass Water District, and local reservoirs. The city has invested heavily in groundwater management and recharge, operating artificial recharge ponds and implementing advanced conservation programs. San Jose’s proximity to the tech industry has driven innovation in smart water management, including extensive use of digital monitoring systems and automated leak detection throughout its distribution network.
San Jose Water Quality: Current Status (2024-2025)
Latest Testing Results
- Lead Levels: The most recent testing period (January-December 2023) showed 90th percentile lead levels of 2.1 parts per billion (ppb), well below the EPA action level of 15 ppb, reflecting effective corrosion control and relatively modern infrastructure.
- Testing Scope: San Jose Water Company conducts over 25,000 water quality tests annually, including routine monitoring at hundreds of residential locations, focusing on homes with the highest likelihood of lead exposure.
- Compliance Status: San Jose’s water meets or exceeds all federal and state drinking water standards, maintaining a perfect compliance record since the Safe Drinking Water Act was enacted.
Diverse Water Sources
- Groundwater Resources: Approximately 45% of San Jose’s water comes from the Santa Clara Valley groundwater basin, which is actively managed and recharged to prevent overdraft.
- Surface Water Supplies: About 35% comes from the California State Water Project (Sacramento-San Joaquin Delta) and 15% from Pacheco Pass Water District (San Luis Reservoir).
- Local Reservoirs: Remaining supplies come from local surface reservoirs in the Santa Cruz Mountains, providing high-quality supplement during wet years.
Advanced Treatment Technology
- Groundwater Treatment: Multiple groundwater treatment plants utilize advanced oxidation processes, granular activated carbon, and biological filtration to remove emerging contaminants.
- Surface Water Processing: The Santa Teresa Water Treatment Plant employs state-of-the-art membrane filtration, ozonation, and UV disinfection for comprehensive contaminant removal.
- Corrosion Control: Optimized orthophosphate treatment prevents lead and copper leaching, with dosages fine-tuned based on extensive distribution system modeling.
Silicon Valley Innovation
- Smart Water Networks: Advanced metering infrastructure with real-time monitoring helps detect leaks immediately and optimizes system pressure to reduce water loss.
- Water Conservation Technology: Pilot programs include AI-powered irrigation optimization for large landscape areas and smart home water management systems.
- Groundwater Management: State-of-the-art groundwater recharge facilities and monitoring wells ensure sustainable aquifer management for future generations.
Environmental Stewardship
San Jose’s commitment to water sustainability includes extensive watershed protection programs, participation in regional water recycling initiatives, and innovative drought management strategies. The city leads in groundwater recharge operations, utilizing treated surface water and advanced-treated recycled water to maintain aquifer levels. San Jose Water Company has reduced system water loss to just 8% through proactive pipeline replacement and real-time leak detection, setting a benchmark for water efficiency in urban California.
Recommendations for San Jose Residents
Embrace Smart Water Use
Take advantage of Silicon Valley innovation by installing smart irrigation controllers and using the MySJWater portal to monitor usage. Set up leak alerts to catch problems early and save money.
Conserve During Drought
Follow state and local water restrictions, including limited outdoor watering schedules. Consider drought-tolerant landscaping and take advantage of turf replacement rebates available through the water district.
Monitor Your Water
Request water quality testing through San Jose Water Company at (408) 279-7900 if you have concerns. Review the annual Water Quality Report for comprehensive data on your local water supply.
Use Cold Water
Always use cold water for drinking and cooking, as hot water may contain higher levels of metals from plumbing. If water hasn’t been used for 6+ hours, run for 30-60 seconds before consumption.
Protect Water Quality
Properly dispose of medications, chemicals, and household hazardous waste. Participate in community watershed protection events and educational programs to help maintain our local water sources.
Frequently Asked Questions
Is San Jose’s tap water safe to drink?
Yes, San Jose’s tap water is safe and meets all federal and state drinking water standards. The water undergoes extensive treatment and testing, with over 25,000 quality tests performed annually. San Jose Water Company maintains one of the most rigorous testing programs in California, monitoring for over 300 compounds.
The city’s diverse water sources are treated using advanced technologies including membrane filtration, ozonation, and UV disinfection. Each source is blended and treated to optimize water quality throughout the distribution system. If you live in a home built before 1987, consider using NSF-certified filters as an additional precaution against potential lead in household plumbing.
Where does San Jose’s water come from?
San Jose relies on a diverse portfolio of water sources, making our supply more resilient to drought and other challenges:
• Groundwater (45%): Local aquifers recharged through natural and artificial means
• State Water Project (35%): Imported from Northern California via the Sacramento-San Joaquin Delta
• Pacheco Pass Water District (15%): Surface water from San Luis Reservoir
• Local Surface Water (5%): Reservoirs in the Santa Cruz Mountains
This diversification helps ensure reliable water supply during varying weather conditions and drought periods.
How does Silicon Valley influence water management?
San Jose’s location in Silicon Valley has driven technological innovation in water management, including:
• Advanced Metering Infrastructure: Real-time consumption monitoring and leak detection
• Smart Irrigation Systems: AI-powered controllers that optimize landscape watering
• Data Analytics: Predictive modeling for system maintenance and water quality management
• Mobile Technology: Customer portals and apps for usage tracking and bill management
• Sensor Networks: Comprehensive water quality monitoring throughout the distribution system
These innovations help San Jose achieve industry-leading efficiency with only 8% system water loss, well below the state average.
What are the current water conservation requirements?
San Jose follows California’s statewide requirements and local ordinances for water conservation:
Mandatory Conservation Measures:
• No outdoor watering during or 48 hours after measurable rainfall
• No runoff from irrigation onto hardscapes (sidewalks, streets)
• No hosing down hardscapes (use brooms instead)
• Irrigation limited to 3 days per week maximum
Voluntary Conservation:
• Install water-efficient fixtures and appliances
• Plant drought-resistant landscaping
• Take advantage of rebates for water-saving devices
Check sjwater.com for current drought stage levels and specific restrictions.
Contaminants of Concern
PFAS Compounds
Source: Industrial processes, firefighting foam, and consumer products that have contaminated some groundwater sources
Health Effects: Potential increased cancer risk, decreased vaccine response, increased cholesterol, and reproductive effects
Current Status: Detected at very low levels in some wells; affected sources use granular activated carbon treatment or are blended with cleaner sources
TCE (Trichloroethylene)
Source: Historical industrial use, particularly in electronics manufacturing (a legacy of Silicon Valley’s industrial past)
Health Effects: Potential liver damage, central nervous system effects, and increased cancer risk with long-term exposure
Current Status: Monitored in all groundwater sources; affected wells use air stripping or carbon filtration to remove TCE to non-detectable levels
Please read – our information
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