Polychlorinated biphenyls (PCBs)
Regional Water Authority
PCBs are synthetic chemicals banned in the U.S. since the 1970s because of their toxicity. PCBs contaminate water by leaching from landfills and hazardous waste clean-up sites. PCBs increase the risk of cancer. Read More.
Up until the late 1970s, PCBs were used widely as coolants and lubricants in transformers, capacitors and other electrical equipment. Currently, PCBs are widely detected in the general population. They build up and are stored in fatty tissues and fluids such as breast milk, and can be passed on to fetuses and infants during pregnancy and breast-feeding. In human epidemiological studies, PCBs have been associated with an elevated risk of breast and prostate cancers. Infants and children with higher PCB exposures during development score lower on measures of neurological function, ranging from decreased IQ scores to� reduced hearing sensitivity. PCBs also affect hormones and damage the immune system.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2014 | N/A | 0 | 0 | N/A |
| 2015 | ND | 1 | 0 | ND |
| 2016 | ND | 19 | 0 | ND |
| 2017 | N/A | 0 | 0 | N/A |
| 2018 | N/A | 0 | 0 | N/A |
| 2019 | ND | 22 | 0 | ND |
ppb = parts per billion
State and national drinking water standards and health guidelines
EWG Health Guideline 0.09 ppb
The EWG Health Guideline of 0.09 ppb for PCBs was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer.
EPA Maximum Contaminant
Level (MCL) 0.5 ppb
The legal limit for PCBs, established in 1991, was based on analytical detection limits at the time that the standard was set. This limit may not fully protect against the risk of cancer due to PCB exposure.
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2015-06-25 | SOC 200419193 | ND |
| 2016-05-16 | SOC 200439626 | ND |
| 2016-05-16 | SOC 200439625 | ND |
| 2016-05-16 | SOC 200439623 | ND |
| 2016-05-16 | SOC 200439622 | ND |
| 2016-05-16 | SOC 200439619 | ND |
| 2016-05-16 | SOC 200439620 | ND |
| 2016-05-16 | SOC 200439627 | ND |
| 2016-05-16 | SOC 200439628 | ND |
| 2016-08-29 | SOC 200448468 | ND |
| 2016-08-29 | SOC 200448473 | ND |
| 2016-08-29 | SOC 200448472 | ND |
| 2016-08-29 | SOC 200448466 | ND |
| 2016-08-29 | SOC 200448465 | ND |
| 2016-08-29 | SOC 200448469 | ND |
| 2016-08-29 | SOC 200448470 | ND |
| 2016-08-29 | SOC 200448471 | ND |
| 2016-08-30 | SOC 200448554 | ND |
| 2016-09-28 | SOC 200451204 | ND |
| 2016-11-22 | SOC 200455270 | ND |
| 2019-05-08 | SOC 200531300 | ND |
| 2019-05-28 | SOC 200533720 | ND |
| 2019-05-28 | SOC 200533659 | ND |
| 2019-05-28 | SOC 200533660 | ND |
| 2019-05-28 | SOC 200533803 | ND |
| 2019-05-28 | SOC 200533719 | ND |
| 2019-05-28 | SOC 200533804 | ND |
| 2019-05-29 | SOC 200533881 | ND |
| 2019-05-29 | SOC 200533880 | ND |
| 2019-05-29 | SOC 200533867 | ND |
| 2019-05-29 | SOC 200533868 | ND |
| 2019-08-26 | SOC 200546200 | ND |
| 2019-08-26 | SOC 200546198 | ND |
| 2019-08-26 | SOC 200546197 | ND |
| 2019-08-27 | SOC 200546267 | ND |
| 2019-08-27 | SOC 200546268 | ND |
| 2019-08-27 | SOC 200546302 | ND |
| 2019-08-27 | SOC 200546303 | ND |
| 2019-08-28 | SOC 200546738 | ND |
| 2019-08-28 | SOC 200546737 | ND |
| 2019-08-28 | SOC 200546736 | ND |
| 2019-08-28 | SOC 200546553 | ND |