Tap Water Quality Report
Tap water quality in San Francisco, California
Tap water in San Francisco, California receives a grade of C (76/100) from TapWaterSafety.org. It's served by City of San Francisco Water Department. The most significant water quality concerns are: Lead detected in source water; Haloacetic Acids (HAA5) significantly above health guideline; Chromium-6 detected. Data sources: EPA SDWIS, EPA ECHO, EWG Tap Water Database, and San Francisco's published Consumer Confidence Report.
What's in San Francisco's tap water
Top water quality concerns identified by the EPA and Environmental Working Group across the utility serving San Francisco.
Lead detected in source water
Severe concernLead detected at 3.3 ppb. EWG considers no level of lead safe; EPA's action level is 15 ppb.
Haloacetic Acids (HAA5) significantly above health guideline
Moderate concernHaloacetic Acids (HAA5) detected at 23.7 ppb, 237x above the EWG health guideline of 0.1 ppb.
Chromium-6 detected
Moderate concernChromium-6 detected at 0.28 ppb.
Recommended filters for San Francisco
Filters matched to the specific contaminants in San Francisco's water supply.
Filter certified for lead (NSF/ANSI 53 or 58)
$180-$750When lead is a concern, use a filter certified for lead reduction under NSF/ANSI 53 or 58.
Carbon filter certified for VOCs (NSF/ANSI 53)
$180-$599Activated carbon is effective for disinfection byproducts. Look for NSF/ANSI 53 VOC reduction.
Reverse osmosis certified for chromium (NSF/ANSI 58)
$429-$599Chromium-6 needs reverse osmosis for reliable reduction. Standard carbon filters do not address it.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
All contaminants detected in San Francisco's tap water
Every contaminant identified, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal. Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Haloacetic Acids (HAA5) Disinfection byproduct |
23.7 ppb | 0.1 | 60 | 60 | — | — | 2023 | 237× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
38.4 ppb | 0.6 | 80 | 100 | — | — | 2023 | 64× over |
| Nitrate Inorganic |
2.8 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 2024 | 20× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.339 ppb | 0.02 | — | — | — | 0.02 | 2023 | 17× over |
| Lead Heavy metal |
4.23 ppb | 0 | 15 | 5 | 10 | 0.2 | 2023 | — |
| Contaminant | Detected (2024) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Nitrate Inorganic |
2.8 mg/L | 0.14 | 10 | 11.3 | 11.3 | 10 | 20× over |
| Contaminant | Detected (2023) | EWG | EPA | EU DWD | WHO | CA PHG | Status |
|---|---|---|---|---|---|---|---|
| Haloacetic Acids (HAA5) Disinfection byproduct |
23.7 ppb | 0.1 | 60 | 60 | — | — | 237× over |
| Total Trihalomethanes (TTHMs) Disinfection byproduct |
38.4 ppb | 0.6 | 80 | 100 | — | — | 64× over |
| Chromium-6 (Hexavalent) Heavy metal |
0.339 ppb | 0.02 | — | — | — | 0.02 | 17× over |
| Lead Heavy metal |
4.23 ppb | 0 | 15 | 5 | 10 | 0.2 | — |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines, California OEHHA PHGs, EWG Tap Water Database.
Treatment plant contact info
For service issues, water quality concerns, or to request a Consumer Confidence Report from City of San Francisco Water Department.
General Contact
Water Quality Contact
For questions about contaminants or test results.