Is San Jose, CA Tap Water Safe to Drink?
Graded F — but Copper, 1,4-Dioxane and 4 more were detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
28/100
waterverge.com San Jose, CA — Water Quality Report
San Jose's drinking water received a grade of F (28 out of 100), indicating failing water quality. The city's 64 water systems serve approximately 3,162,368 residents using surface water.
Lead levels were measured at 5.5 ppb (90th percentile), which is within EPA limits but above recommended levels. UCMR 5 testing detected 9 PFAS compounds, with levels exceeding EPA maximum contaminant levels in the water supply.
The system has 556 violations on record, including 142 health-based violations. 126 remain unresolved.
What to know about San Jose's water
San Jose ranks #694 out of 694 cities in California for water quality, placing it among the lowest-rated in the state.
The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection.
Of particular concern: PFAS "forever chemical" levels exceed the 2024 EPA maximum contaminant levels. These synthetic compounds don't break down naturally and require specialized filtration such as reverse osmosis or granular activated carbon.
Hexavalent chromium (chromium-6) was detected at 7.30 µg/L in UCMR 3 testing. While below California's 10 µg/L limit and with no federal MCL set, residents sensitive to this contaminant may consider reverse osmosis filtration.
While lead levels are within EPA limits, they are above the recommended 5 ppb threshold that health organizations consider ideal. A point-of-use filter adds an extra layer of protection.
As a major metropolitan system serving over 3.2M residents, San Jose faces large-scale infrastructure challenges including aging pipes and the complexity of treating water across a vast distribution network.
The system has seen 29 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is San Jose, CA water safe to drink?
San Jose's drinking water has significant quality concerns based on EPA testing data. With a grade of F (28/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 64 water systems serve approximately 3,162,368 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for San Jose
A timeline of significant water quality events, violations, and data updates.
PFAS levels exceed EPA maximum contaminant levels. Reverse osmosis or activated carbon filtration recommended.
Latest EPA compliance and testing data incorporated into San Jose's water quality assessment. Grade: F (28/100).
Contaminants: LEAD AND COPPER RULE REVISIONS, Consumer Confidence Rule.
Contaminants: Public Notice.
Contaminants: Lead and Copper Rule.
Federal disaster declaration (FEMA DR-3592). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for San Jose's water supply.
Within EPA limits but above the American Academy of Pediatrics recommended level of 1 ppb. An NSF 53-certified filter provides additional protection.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
PFAS "forever chemicals" exceed EPA maximum contaminant levels. Reverse osmosis or granular activated carbon filtration strongly recommended.
The "Erin Brockovich" chemical. There is no federal MCL, but California has set a limit of 10 µg/L. Reverse osmosis filtration is effective at removing hexavalent chromium.
PFAS "forever chemicals" detected
UCMR 5 testing found 9 PFAS compounds in San Jose's water supply. PFAS are synthetic chemicals that persist indefinitely in the environment and the human body.
Violation history
San Jose's water system has 556 total violations on record, including 142 health-based violations. 126 remain unresolved. 29 violations were issued in the last 5 years.
Flood & environmental risk
Santa Clara County has experienced 10 federally declared disasters since 2005. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Guadalupe R, Saratoga C A Saratoga, Coyote C Nr Edenvale, Coyote C Ab Hwy 237 A Milpitas, Arroyo Hondo Nr San Jose.
Where does San Jose's water come from?
San Jose's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 64 water systems serving approximately 3,162,368 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Guadalupe R (river), Saratoga C A Saratoga (river), Coyote C Nr Edenvale (river), Coyote C Ab Hwy 237 A Milpitas (river), Arroyo Hondo Nr San Jose (river).
What San Jose residents can do
Recommended: Reverse osmosis system. This addresses the specific contaminants found in San Jose's water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.
San Jose's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Forever chemicals overview
National PFAS report →Violation summary
Violations & advisories
Top industrial polluters within 10 miles of San Jose
Industrial polluters nearby
Reported releases to surface water by facilities near San Jose, ranked by pounds discharged annually.
Total reported releases to surface water: 12 lbs
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
BURKE INDUSTRIES INC SAN JOSE, CA95112 | Zinc compounds | 8 | 2.3 mi |
HILL BROTHERS CHEMICAL CO SAN JOSE, CA95131 | Ammonia | 3 | 8.1 mi |
TTM TECHNOLOGIES N.A. LLC SANTA CLARA, CA95050 | Copper compounds | 1 | 8.4 mi |
GRANITE ROCK SAN JOSE, CA95133 | Barium | 0 | 6.3 mi |
ANALOG DEVICES INC MILPITAS, CA95035 | — | — | 9.5 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Superfund sites within 10 miles of San Jose
Superfund sites nearby
Federally tracked hazardous-waste sites on the EPA National Priorities List. Proximity does not necessarily indicate tap-water contamination — the connection depends on hydrology and treatment.
- LORENTZ BARREL DRUM CO3.2 mi
- FAIRCHILD SEMICONDUCTOR CORP SOUTH SAN JOSE PLANT4.9 mi
Source: EPA Superfund National Priorities List
Flood & disaster history
Santa Clara County has experienced 10 federally declared disasters since 2005. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in San Jose's water supply, we recommend the following filter types.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 5.5 | 15 | ppb | Inorganic | Safe |
| Copper (90th percentile) CopperInorganic A metal that enters drinking water mainly through corrosion of copper plumbing. Small amounts are essential for health, but excess levels are harmful. Health EffectsGastrointestinal distress (nausea, vomiting, diarrhea) at short-term high levels; liver and kidney damage from long-term exposure. EPA Limit1.3 mg/L action level Common SourcesCorrosion of copper household plumbing, erosion of natural deposits. | 1.59 | 1.3 | mg/L | Inorganic | Over Limit |
| 11Cl-PF3OUdS | ND | HI | µg/L | PFAS | Not Detected |
| 4:2 FTS | ND | HI | µg/L | PFAS | Not Detected |
| 6:2 FTS 6:2 FTSPFAS A fluorotelomer sulfonate commonly found at sites contaminated with aqueous film-forming foam (AFFF) used in firefighting. Health EffectsPotential liver toxicity and endocrine disruption. Less studied but identified as a contaminant of concern. EPA LimitNo individual MCL (not yet regulated) Common SourcesFirefighting foam (AFFF), airports, military bases, and industrial facilities. | ND | HI | µg/L | PFAS | Not Detected |
| 8:2 FTS | ND | HI | µg/L | PFAS | Not Detected |
| 9Cl-PF3ONS | ND | HI | µg/L | PFAS | Not Detected |
| ADONA | ND | HI | µg/L | PFAS | Not Detected |
| HFPO-DA HFPO-DA (GenX)PFAS A replacement for PFOA in manufacturing, marketed as safer but still a persistent "forever chemical." Also known as GenX. Health EffectsLiver and kidney effects, reproductive toxicity, immune system effects, and potential cancer risk. EPA Limit10 ppt MCL Common SourcesFluoropolymer manufacturing (used as PFOA replacement), industrial wastewater discharge. | ND | 0.01 | µg/L | PFAS | Not Detected |
| lithium LithiumInorganic A naturally occurring alkali metal found in groundwater. Monitored under UCMR 5 to assess occurrence in drinking water. Health EffectsKidney effects at high doses. Low-level exposure effects under study; some research suggests neurological effects. EPA LimitNo MCL (monitoring only under UCMR 5) Common SourcesNatural mineral deposits, geothermal water, and industrial discharge. | 81.300 | HI | µg/L | PFAS | Detected |
| NEtFOSAA | ND | HI | µg/L | PFAS | Not Detected |
| NFDHA | ND | HI | µg/L | PFAS | Not Detected |
| NMeFOSAA | ND | HI | µg/L | PFAS | Not Detected |
| PFBA PFBAPFAS One of the shortest-chain PFAS compounds. Very mobile in water and difficult to remove with standard filtration. Health EffectsThyroid effects, potential developmental toxicity. Shorter half-life in body than long-chain PFAS. EPA LimitNo individual MCL (not yet regulated) Common SourcesDegradation of longer-chain PFAS, industrial discharge, and firefighting foam. | 0.028 | HI | µg/L | PFAS | Detected |
| PFBS PFBSPFAS A short-chain PFAS used as a replacement for PFOS. While it clears the body faster than long-chain PFAS, it still persists in the environment. Health EffectsThyroid effects, reproductive and developmental toxicity, kidney effects. EPA LimitPart of Hazard Index (1.0) Common SourcesIndustrial discharge, firefighting foam, and as a replacement chemical in manufacturing. | 0.010 | HI | µg/L | PFAS | Detected |
| PFDA | ND | HI | µg/L | PFAS | Not Detected |
| PFDoA | ND | HI | µg/L | PFAS | Not Detected |
| PFEESA | ND | HI | µg/L | PFAS | Not Detected |
| PFHpA PFHpAPFAS A medium-chain PFAS compound found in various environmental samples. Less studied than PFOA/PFOS but still considered a contaminant of concern. Health EffectsLiver effects, potential developmental toxicity, and endocrine disruption. EPA LimitPart of Hazard Index (1.0) Common SourcesDegradation of longer-chain PFAS, industrial discharge, and contaminated water sources. | 0.004 | HI | µg/L | PFAS | Detected |
| PFHpS | ND | HI | µg/L | PFAS | Not Detected |
| PFHxA PFHxAPFAS A short-chain PFAS replacement chemical widely used after manufacturers phased out longer-chain PFAS. Very commonly detected in water. Health EffectsLiver and kidney effects, potential thyroid disruption. Considered less toxic than long-chain PFAS but still persistent. EPA LimitNo individual MCL (not yet regulated) Common SourcesIndustrial processes, firefighting foam (AFFF), food packaging, and textile treatment. | 0.015 | HI | µg/L | PFAS | Detected |
| PFHxS PFHxSPFAS A medium-chain PFAS found in firefighting foam and consumer products. It has a long half-life in the human body, similar to long-chain PFAS. Health EffectsImmune system effects, thyroid disruption, and potential reproductive and developmental harm. EPA LimitPart of Hazard Index (1.0) Common SourcesFirefighting foam (AFFF), waterproof textiles, food packaging, and industrial discharge. | 0.022 | HI | µg/L | PFAS | Detected |
| PFMBA | ND | HI | µg/L | PFAS | Not Detected |
| PFMPA | ND | HI | µg/L | PFAS | Not Detected |
| PFNA PFNAPFAS A long-chain PFAS compound used in manufacturing fluoropolymers. It bioaccumulates in the body and is very persistent in the environment. Health EffectsDevelopmental effects, liver toxicity, immune suppression, and potential cancer risk. EPA LimitPart of Hazard Index (1.0) Common SourcesFluoropolymer manufacturing, industrial emissions, and contaminated water sources. | ND | HI | µg/L | PFAS | Not Detected |
| PFOA PFOAPFAS A long-chain PFAS ("forever chemical") once widely used in nonstick coatings and firefighting foam. It persists in the body and environment for years. Health EffectsLinked to kidney and testicular cancer, thyroid disease, elevated cholesterol, and reproductive issues. EPA Limit4.0 ppt MCL Common SourcesIndustrial discharge, firefighting foam (AFFF), nonstick cookware manufacturing, and contaminated groundwater. | 0.009 | 0.004 | µg/L | PFAS | Over MCL |
| PFOS PFOSPFAS A long-chain PFAS compound historically used in stain-resistant coatings and firefighting foam. One of the most studied and persistent PFAS chemicals. Health EffectsLiver damage, immune system suppression, thyroid disruption, increased cholesterol, and potential cancer risk. EPA Limit4.0 ppt MCL Common SourcesFirefighting foam (AFFF), industrial sites, stain-resistant fabric treatments, and contaminated groundwater. | 0.022 | 0.004 | µg/L | PFAS | Over MCL |
| PFPeA PFPeAPFAS A short-chain PFAS compound commonly detected in drinking water. One of the most frequently found PFAS in UCMR 5 monitoring. Health EffectsLess studied than PFOA/PFOS. Potential liver and thyroid effects. Research is ongoing. EPA LimitNo individual MCL (not yet regulated) Common SourcesIndustrial discharge, firefighting foam degradation, and consumer products. | 0.034 | HI | µg/L | PFAS | Detected |
| PFPeS | ND | HI | µg/L | PFAS | Not Detected |
| PFTA | ND | HI | µg/L | PFAS | Not Detected |
| PFTrDA | ND | HI | µg/L | PFAS | Not Detected |
| PFUnA | ND | HI | µg/L | PFAS | Not Detected |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how San Jose compares by contaminant
Explore where San Jose ranks among all California cities for specific contaminants.
Water source & infrastructure
Where San Jose's water comes from
San Jose's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.
Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards.
These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge.
The system is operated by private ownership and serves approximately 3,162,368 people through 64 water systems.
Water bodies near San Jose
San Jose is located near 5 notable water bodies. As a surface water system, these water bodies may directly influence the city's drinking water supply.
Water systems serving San Jose
| System Name | PWSID | Population | Source |
|---|---|---|---|
| SAN JOSE WATER | CA4310011 | 1,039,920 | SW |
| CWS - BAKERSFIELD | CA1510003 | 267,881 | SW |
| CALIFORNIA WATER SERVICE - STOCKTON | CA3910001 | 176,266 | SWP |
| CALIFORNIA WATER SERVICE CO. - ELA | CA1910036 | 152,474 | SWP |
| CWS - VISALIA | CA5410016 | 148,496 | GW |
| CALIFORNIA WATER SERVICE CO. - DOMINGUEZ | CA1910033 | 143,996 | SWP |
| CWSC SALINAS | CA2710010 | 123,679 | GW |
| CAL-WATER SERVICE CO.-CHICO | CA0410002 | 114,925 | GW |
| GREAT OAKS WC INC | CA4310022 | 110,088 | GW |
| CALIFORNIA WATER SERVICE - SAN MATEO | CA4110008 | 102,348 | SWP |
| CITY OF SAN JOSE - EVG/EDV/COY | CA4310020 | 101,265 | SWP |
| CALIFORNIA WATER SERVICE CO. - HERM/REDO | CA1910134 | 96,853 | SWP |
| CALIFORNIA WATER SERVICE CO. - PALOS VER | CA1910104 | 71,452 | SWP |
| CWSC LOS ALTOS SUBURBAN | CA4310001 | 69,973 | SWP |
| CALIFORNIA WATER SERVICE-S SAN FRANCISCO | CA4110009 | 64,146 | SWP |
| CALIFORNIA WATER SERVICE - BEAR GULCH | CA4110006 | 61,431 | SW |
| CALIFORNIA WATER SERVICE - LIVERMORE | CA0110003 | 60,414 | SWP |
| CITY OF SAN JOSE - NSJ/ALVISO | CA4310019 | 45,559 | SWP |
| CALIFORNIA WATER SERVICE - SAN CARLOS | CA4110007 | 35,344 | SWP |
| CWS - SELMA | CA1010024 | 26,517 | GW |
| CWS - NORTH GARDEN | CA1510055 | 22,762 | SW |
| CALIFORNIA WATER SERVICE CO - WESTLAKE | CA5610016 | 19,533 | SWP |
| CALIFORNIA WATER SERVICE CO.-TRAVIS AFB | CA4810701 | 18,111 | SWP |
| CWSC KING CITY | CA2710009 | 16,334 | GW |
| CAL-WATER SERVICE CO.-MARYSVILLE | CA5810001 | 12,419 | GW |
| CAL-WATER SERVICE CO.-OROVILLE | CA0410005 | 11,106 | SW |
| CALIFORNIA WATER SERVICE CO. - DIXON | CA4810002 | 10,623 | GW |
| CAL-WATER SERVICE CO.-WILLOWS | CA1110003 | 7,240 | GW |
| CWSC SALINAS HILLS | CA2710012 | 5,293 | GW |
| TESORO VIEJO MASTER MWC, INC. | CA2010017 | 3,885 | SW |
| CWSC OAK HILLS | CA2710019 | 3,161 | GW |
| CWS - KERNVILLE | CA1510033 | 2,572 | SW |
| LUCERNE WATER CO. - CAL WATER SERVICE | CA1710005 | 2,129 | SW |
| CWSC LAS LOMAS | CA2710013 | 2,084 | GW |
| CALIFORNIA WATER SERVICE CO.-LANCASTER | CA1910010 | 1,387 | SWP |
| CWS SOUTHLAKE SYSTEM | CA1510039 | 1,112 | GW |
| WESTFIELD GARDEN MOBILE HOME PARK | TX1011947 | 942 | GW |
| CALIFORNIA WATER SERVICE CO-LAKE HUGHES | CA1910242 | 929 | GW |
| CALIFORNIA WATER SERVICE CO-LEONA VALLEY | CA1910243 | 878 | SWP |
| CWS - LOWER BODFISH WATER SYSTEM | CA1510056 | 736 | GW |
| CWS - TULCO WATER COMPANY | CA5410041 | 716 | GW |
| CEDAR GROVE MOBILE HOME PARK | TX0500043 | 595 | SWP |
| MISSION OAKS MOBILE HOME PARK | CA3510006 | 550 | GW |
| RIVERBEND MHP | OK3007232 | 500 | SWP |
| ARMSTRONG VALLEY-CAL WATER SERVICE (PUC) | CA4910018 | 473 | GW |
| COAST SPRINGS - CAL. WATER SERVICE (PUC) | CA2110007 | 388 | SW |
| CWS - UPPER BODFISH WATER SYSTEM | CA1510026 | 307 | GW |
| MT. PLEASANT WATER USERS ASSOCIATION | CA4300563 | 300 | SWP |
| CWS - LAKELAND | CA1510049 | 294 | GW |
| CWS-ONYX WATER SYSTEM | CA1510043 | 284 | GW |
| CWS-SPLIT MOUNTAIN WATER SYSTEM | CA1500407 | 226 | GU |
| LONGHORN MOBILE HOME COMMUNITY | TX1010587 | 220 | GWP |
| CWS - FREMONT VALLEY | CA1500333 | 167 | GW |
| BELLA LAGO MOBILE HOME PARK | CA1700610 | 152 | GW |
| ROSEVIEW HEIGHTS MUTUAL WATER COMPANY | CA4300562 | 148 | SWP |
| KENNON WATER COMPANY | CA4300521 | 142 | SWP |
| CWS - MULLEN WATER COMPANY | CA5400935 | 138 | GW |
| CWS-GRAND OAKS WATER SYSTEM | CA1500374 | 122 | GW |
| RANCHO DEL PARADISO-CAL WATER SVC (PUC) | CA4900514 | 94 | GWP |
| LAKE SAN ANTONIO MHP WS | CA2701906 | 84 | GW |
| HAWKINS WATER CO-CAL WATER SERVICE (PUC) | CA4900546 | 81 | GW |
| NOEL HEIGHTS-CAL WATER SERVICE (PUC) | CA4900785 | 79 | GU |
| ABORN HEIGHTS WATER MUTUAL ASSOCIATION | CA4300792 | 45 | GW |
| SANTA CLARA VALLEY WATER DISTRICT | CA4310027 | — | SW |
How San Jose compares
Full California rankings →San Jose's score of 28/100 is below the average of 58/100 among major California cities. 10 of 10 nearby cities score higher.
Nearby cities
View California rankings →Compare San Jose water quality
Head-to-head reports vs other large US cities — grades, lead, PFAS, and Superfund / TRI proximity.
- San Jose vs Los Angeles, CA
- San Jose vs Oakland, CA
- San Jose vs San Diego, CA
- San Jose vs Sacramento, CA
- San Jose vs Burlingame, CA
About San Jose, CA
Wikipedia →San Jose, officially the City of San José, is the most populous city in the San Francisco Bay Area and Northern California, and the 12th-most populous in the United States, with 997,368 residents. The city's metropolitan area is home to nearly two million people, while the broader combined statistical area has a population of over nine million. Located in the center of the Santa Clara Valley on the southern shore of San Francisco Bay, San Jose covers an area of 179.97 sq mi (466.1 km2) and is the seat of Santa Clara County.
Learn more about your water
Guides and resources related to San Jose's water quality findings.
Explore water quality across Santa Clara
Frequently asked questions
Is San Jose, CA tap water safe to drink?
San Jose's water quality earned a grade of F (28/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #694 out of 694 cities tested in California.
What contaminants are in San Jose's water?
Lead was measured at 5.5 ppb (90th percentile). 9 PFAS compounds were detected. 556 violations are on record.
How is San Jose's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in San Jose?
While lead levels are within EPA limits, a filter adds extra protection. PFAS compounds exceed EPA limits — a reverse osmosis or activated carbon filter is recommended.
Where does San Jose's water come from?
San Jose's water is sourced from Surface water. The city has 64 water systems serving approximately 3,162,368 residents.
What health violations has San Jose's water system had?
San Jose has 142 health-based violations on record. The most recent violation was recorded in July 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 126 violations remain unresolved.
Why does San Jose have so many PFAS compounds in its water?
9 different PFAS "forever chemical" compounds were detected in San Jose's water supply during UCMR 5 testing. PFAS contamination often originates from proximity to military installations (AFFF firefighting foam), airports, industrial manufacturing sites, or wastewater treatment facilities. Some levels exceed the 2024 EPA maximum contaminant levels — a reverse osmosis or NSF-certified activated carbon filter is strongly recommended.
How does San Jose's water compare to other cities?
San Jose ranks #694 out of 694 cities in California (better than 0% of state cities) and #15721 out of 15744 cities nationally (0th percentile). The grade of F reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.