San Jose, CA tap water: what's in it in 2025
Serving 1M residents via San Jose Water Company · San Jose, CA drinking water is supplied by San Jose Water Company. EPA and utility monitoring commonly focus on issues such as Chromium-6, PFAS from tech industry, Nitrates from agriculture. Neighborhood water age varies with dead-end mains, fire-flow loops, and construction-related reroutes—small changes that can nudge taste, color, and DBP numbers at the tap. Use the ZIP tool to align this overview with the contaminant list and violation history for the exact PWSID serving your meter.
San Jose has significant water quality concerns including chromium-6. EPA legal limits are set based on treatment feasibility — not always on what independent health scientists consider safe. Certified filtration is strongly recommended for this water supply.
Silicon Valley has a troubling history of industrial chemical contamination in groundwater.
San Jose Water serves areas with legacy tech-industry Superfund sites that have impacted aquifers.
Chromium-6 has been detected in Bay Area water above California health goals.
Nitrates from agricultural Santa Clara Valley land use add to the contamination profile.
Source: EPA UCMR5 national monitoring dataset · Testing period 2023–2025 · MCL = Maximum Contaminant Level (legally enforceable limit) · Health limit = EPA health advisory threshold
Based on San Jose's water profile above, here's the exact system we recommend — and why it's right for this water supply specifically.
COMMON QUESTIONS
Is San Jose tap water safe to drink in 2025?
San Jose water meets EPA legal standards, but meeting legal standards is not the same as being free of health concerns. EPA limits are set based on treatment feasibility, not always on what independent scientists consider safe. San Jose has chromium-6 which is a significant concern — certified filtration is strongly recommended.
Does San Jose water have PFAS?
EPA UCMR5 monitoring data for San Jose (water system CA4310004) is shown above. PFAS — sometimes called "forever chemicals" — are synthetic compounds that don't break down in the body. Only reverse osmosis systems or NSF 58-certified carbon block filters reliably remove PFAS from tap water. Standard pitcher filters do not remove PFAS.
Does San Jose water have lead?
Lead in tap water almost always comes from the pipes inside your home or building, not the treatment plant. Homes built before 1986 in San Jose are most at risk because they may have lead solder, brass fittings, or lead service lines. The EPA has no safe level for lead in children. An NSF/ANSI 53-certified filter or reverse osmosis system removes lead at the tap.
What water filter is best for San Jose?
For San Jose's water profile — chromium-6, pfas from tech industry — a reverse osmosis system addresses the widest range of contaminants. Under-sink RO (Waterdrop G3P800, Aquasana SmartFlow) is the gold standard for homeowners. Renters can use a countertop RO like the Waterdrop D4 — zero installation required. Clearly Filtered pitchers are the best non-RO option for PFAS and lead.
How do I get my San Jose water tested?
For the most accurate results for your specific tap, use a certified mail-in lab test rather than relying on city-wide data. SimpleLab Tap Score tests for 100+ contaminants including PFAS, lead, arsenic, and nitrates. Results come with a detailed health assessment and filter recommendations. City-wide EPA data like what you see above is a strong baseline, but your home's plumbing can add contaminants after the water leaves the treatment plant.
As of October 2024, all US water utilities must publish a public inventory of their lead service lines — the pipes connecting the water main to your home. Even if your utility water tests clean at the treatment plant, lead can leach from these pipes into your tap. Homes built before 1986 are most at risk.
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City-wide data is just the start. Enter your ZIP to see your exact water system's EPA report, PFAS levels, and violation history — then get the right filter for your home.
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