Drinking water quality · 2025
· Verified
What's in City of Santa Clara, CA tap water
99 contaminants were measured in the City of Santa Clara, CA water system's 2025 annual report. Each is shown below against its federal limit.
- Reporting year
- 2025
- Contaminants measured
- 99
- Over federal limit
- 0
- Approaching the limit
- 0
- Service area
- CA
state-level CCR
PFAS — EPA UCMR5 (2023–2025)
1 PFAS compound detected in City of Santa Clara, CA
The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.
Lithium
● Detected (no federal limit)Measured 11 mg/LSample year 2025Samples 1 detect / 15
below national p90 (76.59999999999991 mg/L across detecting U.S. systems)
PWSID CA4310012 · Source: EPA UCMR5. Limits per EPA's April 2024 PFAS National Primary Drinking Water Regulation. PFAS values reported in nanograms per liter (ng/L) — note that 1 ng/L = 1 part per trillion.
Where your water comes from · EPA SDWIS
City of Santa Clara, CA's drinking water comes from ground water, drawn from 21 sources.
Source
21ground water
- WELL · 13
- WELL 13-02
- WELL 22-02
- WELL 18-02
- + 5 more
Treatment
0treatment plants
Distribution
0storage units
Also buys water from SANTA CLARA VALLEY WATER DISTRICT, SAN FRANCISCO REGIONAL WATER SYSTEM.
Source: EPA SDWIS facilities inventory. Methodology.
Historical readings · EPA Six-Year Review (2012–2019)
1 contaminant historically over EPA limits in City of Santa Clara, CA
Every U.S. public water system reports compliance-monitoring data to EPA. The Six-Year Review releases the 2012–2019 window as a single dataset — here's what your system reported, year by year. Values shown are the highest detection per analyte per year, compared to the federal MCL.
| Contaminant | Worst detection | EPA limit | Years (2012–2019) |
|---|---|---|---|
TTHM worst: 2016 | 0.089 mg/L 1.1× | 0.08 mg/L | '12'13'14'15'16'17'18'19 |
HAA5 worst: 2018 | 0.056 mg/L 93% | 0.06 mg/L | '12'13'14'15'16'17'18'19 |
NITRATE worst: 2014 | 6.55 mg/L within | 10 mg/L | '12'13'14'15'16'17'18'19 |
NITRATE NITRITE worst: 2016 | 6.1 mg/L within | 10 mg/L | '15'16'17'18'19 |
ARSENIC worst: 2014 | 0.0048 mg/L within below national p90 | 0.01 mg/L | '14'17'18 |
BARIUM worst: 2013 | 0.21 mg/L within near national p90 | 2 mg/L | '12'13'14'15'16'17'18'19 |
FLUORIDE worst: 2017 | 0.19 mg/L within | 4 mg/L | '12'13'14'15'16'17'18'19 |
TCAA worst: 2012 | 0.021 mg/L | — | '12'13'14'15'16'17'18'19 |
DBAA worst: 2012 | 0.0066 mg/L | — | '12'13'14'15'16'17'18'19 |
DCAA worst: 2012 | 0.017 mg/L | — | '12'13'14'15'16'17'18'19 |
MBAA worst: 2012 | 0.0018 mg/L | — | '12'13'14'16'19 |
MCAA worst: 2017 | 0.002 mg/L | — | '17'18'19 |
BROMODICHLOROMETHANE worst: 2012 | 0.02 mg/L | — | '12'13'14'15'16'17'18'19 |
BROMOFORM worst: 2012 | 0.014 mg/L | — | '12'13'14'15'16'17'18'19 |
CHLOROFORM worst: 2012 | 0.064 mg/L | — | '12'13'14'15'16'17'18'19 |
DIBROMOCHLOROMETHANE worst: 2012 | 0.027 mg/L | — | '12'13'14'15'16'17'18'19 |
PWSID CA4310012 · Source: EPA Six-Year Review 4 (2012–2019). Values are the highest detection in each calendar year; non-detect years are omitted. Year tags above show every year with a detection.
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ManganeseA naturally occurring metal from soil and rock. | 35.71052631578947 UG/LAverageSource water | 50 UG/LMCL | Within the limit |
| IronA naturally occurring metal common in groundwater. | 191 UG/LAverageSource water | 300 UG/LMCL | Within the limit |
| Chromium, HexavalentHexavalent chromium ('chromium-6') — the more toxic form of chromium. | 1.6170588235294117 UG/LAverageSource water | 10 UG/LMCL | Within the limit |
| AluminumA common element sometimes used as a treatment coagulant. | Not detected UG/LHighest single sampleSource water | 1000 UG/LMCL | None detected |
| Antimony | Not detected UG/LHighest single sampleSource water | 6 UG/LMCL | None detected |
| Beryllium | Not detected UG/LHighest single sampleSource water | 4 UG/LMCL | None detected |
| Cadmium | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| CopperA metal that enters water from corroding household plumbing. | Not detected UG/LHighest single sampleSource water | 1000 UG/LMCL | None detected |
| LeadA toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. | Not detected UG/LHighest single sampleSource water | None set | None detected |
| MercuryA toxic metal from erosion of natural deposits and industrial runoff. | Not detected UG/LHighest single sampleSource water | 2 UG/LMCL | None detected |
| NickelA metal from natural deposits and industrial discharge. | Not detected UG/LHighest single sampleSource water | 100 UG/LMCL | None detected |
| SeleniumA trace element from natural deposits and industrial discharge. | Not detected UG/LHighest single sampleSource water | 50 UG/LMCL | None detected |
| Thallium | Not detected UG/LHighest single sampleSource water | 2 UG/LMCL | None detected |
| ZincA naturally occurring metal that can also enter water from corroding pipes. | Not detected UG/LHighest single sampleSource water | 5000 UG/LMCL | None detected |
| CalciumA naturally occurring mineral that contributes to water hardness. | 44.730000000000004 MG/LAverageSource water | None set | Detected — no federal limit |
| MagnesiumA naturally occurring mineral that contributes to water hardness. | 21.02 MG/LAverageSource water | None set | Detected — no federal limit |
| PotassiumA naturally occurring mineral from rock and soil. | 1.295 MG/LAverageSource water | None set | Detected — no federal limit |
| SodiumA naturally occurring salt component. | 29.15 MG/LAverageSource water | None set | Detected — no federal limit |
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts. | 449.8 MG/LAverageSource water | 1000 MG/LMCL | Within the limit |
| Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content. | 652.9 UMHO/CMAverageSource water | 1600 UMHO/CMMCL | Within the limit |
| TurbidityA measure of cloudiness from suspended particles in the water. | 1.7361538461538462 NTUAverageSource water | 5 NTUMCL | Within the limit |
| OdorA measure of detectable smell in the water. | 0.75 TONAverageSource water | 3 TONMCL | Within the limit |
| ColorA measure of visible tint in the water. | 2.3 UNITSAverageSource water | 15 UNITSMCL | Within the limit |
| AlkalinityA measure of the water's capacity to neutralize acids. | 152.8 MG/LAverageSource water | None set | Detected — no federal limit |
| HardnessA measure of dissolved calcium and magnesium minerals. | 297.2 MG/LAverageSource water | None set | Detected — no federal limit |
| pHA measure of how acidic or basic the water is. | 7.704000000000001 PHAverageSource water | None set | Detected — no federal limit |
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| PerchlorateA chemical used in rocket fuel and fireworks that can also form during disinfection. | 0.96 UG/LAverageSource water | 6 UG/LMCL | Within the limit |
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChlorideA naturally occurring salt compound. | 54.5 MG/LAverageSource water | 500 MG/LMCL | Within the limit |
| SulfateA naturally occurring mineral from rock and soil. | 21.601225 UG/LAverageSource water | 500 UG/LMCL | Within the limit |
| Cyanide | Not detected UG/LHighest single sampleSource water | 150 UG/LMCL | None detected |
| NitriteA compound from fertilizer runoff, sewage, and erosion of natural deposits. | Not detected MG/LHighest single sampleSource water | 1 MG/LMCL | None detected |
Other
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Carbofuran | Not detected UG/LHighest single sampleSource water | 18 UG/LMCL | None detected |
| Carbon Tetrachloride | Not detected UG/LHighest single sampleSource water | 0.5 UG/LMCL | None detected |
| Chlordane | Not detected UG/LHighest single sampleSource water | 0.1 UG/LMCL | None detected |
| Chlorobenzene | Not detected UG/LHighest single sampleSource water | 70 UG/LMCL | None detected |
| Chromium | Not detected UG/LHighest single sampleSource water | 50 UG/LMCL | None detected |
| Cis Dichloroethylene 12 | Not detected UG/LHighest single sampleSource water | 6 UG/LMCL | None detected |
| Deha | Not detected UG/LHighest single sampleSource water | 400 UG/LMCL | None detected |
| Dehp | Not detected UG/LHighest single sampleSource water | 4 UG/LMCL | None detected |
| Dichloroethane 12 | Not detected UG/LHighest single sampleSource water | 0.5 UG/LMCL | None detected |
| Dichloroethylene 11 | Not detected UG/LHighest single sampleSource water | 6 UG/LMCL | None detected |
| Dichloropropane 12 | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| Dinoseb | Not detected UG/LHighest single sampleSource water | 7 UG/LMCL | None detected |
| Diquat | Not detected UG/LHighest single sampleSource water | 20 UG/LMCL | None detected |
| Edb | Not detected UG/LHighest single sampleSource water | 0.05 UG/LMCL | None detected |
| Endothall | Not detected UG/LHighest single sampleSource water | 100 UG/LMCL | None detected |
| Endrin | Not detected UG/LHighest single sampleSource water | 2 UG/LMCL | None detected |
| Glyphosate | Not detected UG/LHighest single sampleSource water | 700 UG/LMCL | None detected |
| Heptachlor | Not detected UG/LHighest single sampleSource water | 0.01 UG/LMCL | None detected |
| Heptachlor Epoxide | Not detected UG/LHighest single sampleSource water | 0.01 UG/LMCL | None detected |
| Hexachlorobenzene | Not detected UG/LHighest single sampleSource water | 1 UG/LMCL | None detected |
| Hexachlorocyclopentadiene | Not detected UG/LHighest single sampleSource water | 50 UG/LMCL | None detected |
| Methoxychlor | Not detected UG/LHighest single sampleSource water | 30 UG/LMCL | None detected |
| O Dichlorobenzene | Not detected UG/LHighest single sampleSource water | 600 UG/LMCL | None detected |
| Oxamyl | Not detected UG/LHighest single sampleSource water | 50 UG/LMCL | None detected |
| P Dichlorobenzene | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| Pcb Total | Not detected UG/LHighest single sampleSource water | 0.5 UG/LMCL | None detected |
| Pce | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| Pentachlorophenol | Not detected UG/LHighest single sampleSource water | 1 UG/LMCL | None detected |
| Picloram | Not detected UG/LHighest single sampleSource water | 500 UG/LMCL | None detected |
| Styrene | Not detected UG/LHighest single sampleSource water | 100 UG/LMCL | None detected |
| Tce | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| Toxaphene | Not detected UG/LHighest single sampleSource water | 3 UG/LMCL | None detected |
| Trans Dichloroethylene 12 | Not detected UG/LHighest single sampleSource water | 10 UG/LMCL | None detected |
| Trichlorobenzene 124 | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| Trichloroethane 111 | Not detected UG/LHighest single sampleSource water | 200 UG/LMCL | None detected |
| Trichloroethane 112 | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| Twofourd | Not detected UG/LHighest single sampleSource water | 70 UG/LMCL | None detected |
| Vinyl Chloride | Not detected UG/LHighest single sampleSource water | 0.5 UG/LMCL | None detected |
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Combined RadiumCombined radium-226 and radium-228 — naturally occurring radioactive elements. | Not detected PCI/LHighest single sampleSource water | 5 PCI/LMCL | None detected |
VOCs & pesticides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| 1,2,3-TCP | Not detected UG/LHighest single sampleSource water | 0.005 UG/LMCL | None detected |
| AtrazineA widely used agricultural herbicide that reaches water through runoff. | Not detected UG/LHighest single sampleSource water | 1 UG/LMCL | None detected |
| Benzene | Not detected UG/LHighest single sampleSource water | 1 UG/LMCL | None detected |
| Benzo(a)pyrene | Not detected UG/LHighest single sampleSource water | 0.2 UG/LMCL | None detected |
| Chloromethane | Not detected UG/LHighest single sampleSource water | None set | None detected |
| Dalapon | Not detected UG/LHighest single sampleSource water | 200 UG/LMCL | None detected |
| Dichlorodifluoromethane | Not detected UG/LHighest single sampleSource water | None set | None detected |
| Dichloromethane | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| Ethylbenzene | Not detected UG/LHighest single sampleSource water | 300 UG/LMCL | None detected |
| Simazine | Not detected UG/LHighest single sampleSource water | 4 UG/LMCL | None detected |
| Toluene | Not detected UG/LHighest single sampleSource water | 150 UG/LMCL | None detected |
| XylenesA group of industrial solvents found in gasoline and paint. | Not detected UG/LHighest single sampleSource water | 1750 UG/LMCL | None detected |
Source: City of Santa Clara, CA's 2025 Consumer Confidence Report — the annual drinking-water report every U.S. utility is required to publish. The numbers on this page are the utility's own. A water-quality report covers an entire service area, not a single address.
People also ask about City of Santa Clara, CA's water
+Is City of Santa Clara, CA tap water safe to drink in 2025?
Every one of the 99 contaminants measured in City of Santa Clara, CA's 2025 Consumer Confidence Report is below its federal limit. "Safe" under the EPA's drinking-water standards is health-based, not aesthetic — but by those standards, no measured contaminant in this report exceeds its enforceable threshold. Individual health concerns (e.g. immunocompromised, infant, pregnancy) may warrant additional filtering regardless of compliance.
+What contaminants are in City of Santa Clara, CA tap water?
99 contaminants were measured in City of Santa Clara, CA's 2025 Consumer Confidence Report, spanning other, metals, and vocs & pesticides. 79 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Where does the data on this page come from?
Every value is transcribed from City of Santa Clara, CA's 2025 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.
+How often is City of Santa Clara, CA's water quality data updated?
Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2025 report; a new report will replace it once the utility publishes its next annual update.
More water systems in CA
City of Santa ClaraCity of Santa ClaraSanta ClaritaSimi ValleyVentura Wwd No. 8 - Simi ValleyVentura Wwd No. 8 - Simi ValleyVentura Wwd No. 8 - Simi ValleyBurbankBurbank-city, Water Dept.Burbank-city, Water Dept.Burbank-city, Water Dept.City of Thousand Oaks Water DepartmentCity of Thousand Oaks Water DepartmentCity of Thousand Oaks Water DepartmentThousand OaksGlendale-city, Water Dept.Glendale-city, Water Dept.Glendale-city, Water Dept.Glendale-city, Water Dept.Los Angeles LADWPLos Angeles-city, Dept. of Water & PowerLos Angeles-city, Dept. of Water & PowerLos Angeles-city, Dept. of Water & PowerPasadenaAll water systems →