Zip 94102 · San Francisco, CA · 1 water systems · EWG data 2013–2023
San Francisco’s tap water has 27 contaminants, 13 above health guidelines.
- Water quality score
- 4out of 10Poor
Counts contaminants above an EWG health guideline, weighted by the harm the guideline protects against. 8 and above is good; 5 and above is fair.
- Above a health guideline
- 13of 27 found
- Linked to cancer
- 12above guideline
- In the SGS test programme
- 7of 27 found
Contaminants found here that SGS measured the Sans Water Purifier against.
Water data: EWG Tap Water Database, utility test results 2013–2023. Guidelines are EWG health guidelines set by federal or state public-health authorities; legal limits differ.
What’s in the water
Worst first. Contaminants Sans has no evidence for come last unless they are above their guideline. Levels are utility averages reported to EWG.
Level found: 39.5 ppb
Health guideline: 0.06 ppb
658×Removed by RO
Level found: 34.4 ppb
Health guideline: 0.1 ppb
344×Removed by RO
Level found: 33.2 ppb
Health guideline: 0.15 ppb
222×Removed by RO
Level found: 9.57 ppb
Health guideline: 0.1 ppb
96×Removed by RO
Level found: 17.1 ppb
Health guideline: 0.2 ppb
86×Removed by RO
Level found: 30.4 ppb
Health guideline: 0.4 ppb
76×Removed by RO
Level found: 2.33 ppb
Health guideline: 0.06 ppb
39×Removed by RO
Level found: 3.28 ppm
Health guideline: 0.14 ppm
23×Tested · >99.9%
Level found: 2.95 ppm
Health guideline: 0.14 ppm
21×Removed by RO
Level found: 0.0788 ppb
Health guideline: 0.004 ppb
20×Tested · >97.2%
10 of 27 contaminants
Tested: measured by SGS on the Sans Water Purifier, the lab’s own figure. Removed by RO: listed by EWG as reduced by reverse osmosis, the purifier’s filter type. Not tested: neither.
Where this report applies
Utilities serving zip 94102. Map data © OpenStreetMap contributors.
What the Sans Water Purifier is tested to reduce
SGS, an ISO/IEC 17025 laboratory, measured the purifier’s reduction of 19 contaminants (Dec 2023 to Mar 2024). These are the worst in San Francisco’s water that were in that programme.
- Nitrate>99.9%Maximum measured reduction
- Arsenic>97.2%Maximum measured reduction
- Hexavalent chromium98.6%Maximum measured reduction
Figures are the laboratory’s own, measured under test conditions. Your tap water differs from the challenge water.