Silver
San Francisco City Water System
Silver occurs naturally in surface and groundwater and can be added to water as a biocide that inhibits growth of bacteria and algae. Increasingly, the use of antimicrobial nano-sized silver particles in consumer products contributes to silver in water sources used for drinking water.
23
Samples
0
Samples exceeding legal limit (MCL)
0
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | ND | 1 | 0 | ND |
| 2015 | N/A | 0 | 0 | N/A |
| 2016 | ND | 1 | 0 | ND |
| 2017 | ND | 1 | 0 | ND |
| 2018 | ND | 15 | 0 | ND |
| 2019 | ND | 5 | 0 | ND |
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2014-06-17 | 9553-001-0824 | ND |
| 2016-06-14 | 9553-001-0920 | ND |
| 2017-06-19 | 9553-001-1015 | ND |
| 2018-01-11 | 9553-007-1115 | ND |
| 2018-03-06 | 9553-004-1031 | ND |
| 2018-03-06 | 9553-008-0914 | ND |
| 2018-03-08 | 9553-006-0925 | ND |
| 2018-06-12 | 9553-004-1058 | ND |
| 2018-06-12 | 9553-008-0930 | ND |
| 2018-06-12 | 9553-006-1012 | ND |
| 2018-06-12 | 9590-006-1012 | ND |
| 2018-06-18 | 9553-001-1025 | ND |
| 2018-09-18 | 9553-006-0945 | ND |
| 2018-09-18 | 9553-004-0855 | ND |
| 2018-09-18 | 9553-008-1025 | ND |
| 2018-12-11 | 9553-006-0915 | ND |
| 2018-12-11 | 9553-004-0845 | ND |
| 2018-12-11 | 9553-008-1045 | ND |
| 2019-06-17 | 9553-006-1206 | ND |
| 2019-06-17 | 9553-004-0956 | ND |
| 2019-06-17 | 9553-007-0905 | ND |
| 2019-06-17 | 9553-008-1106 | ND |
| 2019-06-17 | 9553-001-0905 | ND |