Drinking water quality · 2023
· Verified
What's in San Francisco SFPUC, CA tap water
31 contaminants were measured in the San Francisco SFPUC, CA water system's 2023 annual report. Each is shown below against its federal limit — 1 sit at or above that limit.
- Reporting year
- 2023
- Contaminants measured
- 31
- Over federal limit
- 1
- Approaching the limit
- 0
- Worst contaminant
- Chromium, Total
- Service area
- CA
Where your water comes from · EPA SDWIS
San Francisco SFPUC, CA's drinking water comes from ground water, drawn from 7 sources.
Source
- ZOO
- LAKE MERCED WELL
- WEST SUNSET WELL
- SOUTH SUNSET WELL
- + 3 more
Treatment
- WEST SUNSET CHLORINATION TREATMENT
- ZOO WELL 05 WELLHEAD TREATMENT
Distribution
Also buys water from SAN FRANCISCO REGIONAL WATER SYSTEM.
Historical readings · EPA Six-Year Review (2012–2019)
2 contaminants historically over EPA limits in San Francisco SFPUC, 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) |
|---|---|---|---|
NITRATE worst: 2019 | 13.6 mg/L 1.4× | 10 mg/L | '18'19 |
NITRATE NITRITE worst: 2018 | 11 mg/L 1.1× | 10 mg/L | '18'19 |
PCE worst: 2019 | 0.00247 mg/L within | 0.005 mg/L | '18'19 |
ARSENIC worst: 2016 | 0.0026 mg/L within below national p90 | 0.01 mg/L | '16'17 |
CHROMIUM worst: 2018 | 0.0216 mg/L within 2.2× the national p90 | 0.1 mg/L | '18'19 |
CARBON TETRACHLORIDE worst: 2019 | 0.00099 mg/L within below national p90 | 0.005 mg/L | '18'19 |
FLUORIDE worst: 2016 | 0.677 mg/L within | 4 mg/L | '15'16'18 |
COPPER worst: 2017 | 0.269 mg/L below national p90 | — | '17 |
LEAD worst: 2017 | 0.00673 mg/L | — | '17 |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Chromium, TotalTotal chromium — the sum of all chromium forms, from natural deposits and industrial discharge. | 16 ug/LAverageSystem-wide | 10 ug/LMCL | At or above the limit |
| IronA naturally occurring metal common in groundwater. | 29 ug/LAverageSystem-wide | 300 ug/LMCL | Within the limit |
| BoronA naturally occurring element from rock and soil. | 41 ug/LAverageSystem-wide | 1000 ug/LMCL | Within the limit |
| AluminumA common element sometimes used as a treatment coagulant. | Not detected ug/LAverageSystem-wide | 200 ug/LMCL | Within the limit |
| ManganeseA naturally occurring metal from soil and rock. | Not detected ug/LAverageSystem-wide | 50 ug/LMCL | Within the limit |
| CalciumA naturally occurring mineral that contributes to water hardness. | 15 mg/LAverageSystem-wide | None set | Detected — no federal limit |
| LithiumA naturally occurring element found in some groundwater. | 4.2 ug/LAverageSystem-wide | None set | Detected — no federal limit |
| MagnesiumA naturally occurring mineral that contributes to water hardness. | 5.7 mg/LAverageSystem-wide | None set | Detected — no federal limit |
| SilicaA naturally occurring compound from sand and rock. | 7.5 mg/LAverageSystem-wide | None set | Detected — no federal limit |
| SodiumA naturally occurring salt component. | 16 mg/LAverageSystem-wide | None set | Detected — no federal limit |
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 42 ug/LAverageSystem-wide | 60 ug/LMCL | Within the limit |
| TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. | 49 ug/LAverageSystem-wide | 80 ug/LMCL | Within the limit |
| BromateA disinfection byproduct formed when bromide-containing water is treated with ozone. | 3 ug/LAverageSystem-wide | 10 ug/LMCL | Within the limit |
| ChlorateA byproduct that can form during disinfection, especially when hypochlorite solutions degrade. | 144 ug/LAverageSystem-wide | 800 ug/LMCL | Within the limit |
| PerchlorateA chemical used in rocket fuel and fireworks that can also form during disinfection. | Not detected ug/LAverageSystem-wide | 6 ug/LMCL | Within the limit |
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChloramineA longer-lasting disinfectant made by combining chlorine with ammonia. | 2.6 mg/LAverageSystem-wide | 4 mg/LMRDL | Within the limit |
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content. | 193AverageSystem-wide | 1600MCL | Within the limit |
| Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts. | 102 mg/LAverageSystem-wide | 1000 mg/LMCL | Within the limit |
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.2 NTUAverageSystem-wide | 5 NTUMCL | Within the limit |
| AlkalinityA measure of the water's capacity to neutralize acids. | 60 mg/LAverageSystem-wide | None set | Detected — no federal limit |
| HardnessA measure of dissolved calcium and magnesium minerals. | 60 mg/LAverageSystem-wide | None set | Detected — no federal limit |
| pHA measure of how acidic or basic the water is. | 9.3AverageSystem-wide | None set | Detected — no federal limit |
| TOCTotal organic carbon — a measure of organic material dissolved in the water. | 1.9 mg/LAverageSystem-wide | None set | Detected — no federal limit |
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| SulfateA naturally occurring mineral from rock and soil. | 18 mg/LAverageSystem-wide | 500 mg/LMCL | Within the limit |
| ChlorideA naturally occurring salt compound. | 9.3 mg/LAverageSystem-wide | 500 mg/LMCL | Within the limit |
| BromideA naturally occurring salt found in source water. | Not detected ug/LAverageSystem-wide | None set | Detected — no federal limit |
Microbial
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Giardia lamblia | 0.01AverageSystem-wide | None set | Detected — no federal limit |
People also ask about San Francisco SFPUC, CA's water
+Is San Francisco SFPUC, CA tap water safe to drink in 2023?
The 2023 Consumer Confidence Report for the San Francisco SFPUC, CA water utility lists 1 contaminant at or above the federal limit: Chromium, Total. Whether that means the water is "unsafe" depends on which contaminant, how long the exposure, and individual health factors. The table on this page shows the measured value, the federal threshold, and the regulated statistic used for compliance.
+What contaminants are in San Francisco SFPUC, CA tap water?
31 contaminants were measured in San Francisco SFPUC, CA's 2023 Consumer Confidence Report, spanning metals, physical & aggregate, and disinfection byproducts. 20 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Which contaminants exceed federal limits in San Francisco SFPUC, CA tap water?
One contaminant in San Francisco SFPUC, CA's 2023 report sits at or above the federal limit: Chromium, Total (1.6× the limit). The EPA enforces these limits against the regulated reporting statistic — typically a running annual average or 90th percentile — not a one-off sample spike.
+What is the worst contaminant in San Francisco SFPUC, CA tap water?
The contaminant with the highest measured value relative to its federal limit in the 2023 report is Chromium, Total, at 1.6× the federal threshold. It belongs to the metals family of contaminants.
+Where does the data on this page come from?
Every value is transcribed from San Francisco SFPUC, CA's 2023 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 San Francisco SFPUC, 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 2023 report; a new report will replace it once the utility publishes its next annual update.