Benzene
Regional Water Authority
Benzene is a known human carcinogen. It also damages blood cells and the nervous system. Emissions from petroleum processing, hazardous waste landfills and underground storage tanks contaminate drinking water with benzene. Read More.
To protect against cancer risks, California set a public health goal for benzene in drinking water at 0.15 parts per billion, 30 times lower than the federal legal limit of 5 parts per billion.
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 | ND | 10 | 0 | ND |
| 2015 | ND | 11 | 0 | ND |
| 2016 | ND | 10 | 0 | ND |
| 2017 | ND | 12 | 0 | ND |
| 2018 | ND | 10 | 0 | ND |
| 2019 | ND | 11 | 0 | ND |
ppb = parts per billion
State and national drinking water standards and health guidelines
EWG Health Guideline 0.15 ppb
The EWG Health Guideline of 0.15 ppb for benzene 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) 5 ppb
The legal limit for benzene, established in 1987, 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 benzene exposure.
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2014-03-04 | VOC1 200391964 | ND |
| 2014-03-04 | VOC1 200391963 | ND |
| 2014-03-04 | VOC1 200392007 | ND |
| 2014-03-04 | VOC1 200392005 | ND |
| 2014-03-04 | VOC1 200391980 | ND |
| 2014-03-04 | VOC1 200391978 | ND |
| 2014-03-04 | VOC1 200391977 | ND |
| 2014-03-04 | VOC1 200391965 | ND |
| 2014-03-04 | VOC1 200391979 | ND |
| 2014-03-25 | VOC1 200393100 | ND |
| 2015-03-03 | VOC1 200412899 | ND |
| 2015-03-03 | VOC1 200412902 | ND |
| 2015-03-03 | VOC1 200412900 | ND |
| 2015-03-03 | VOC1 200412879 | ND |
| 2015-03-03 | VOC1 200412881 | ND |
| 2015-03-03 | VOC1 200412907 | ND |
| 2015-03-03 | VOC1 200412923 | ND |
| 2015-03-04 | VOC1 200413022 | ND |
| 2015-03-10 | VOC1 200413328 | ND |
| 2015-03-18 | VOC1 200413713 | ND |
| 2015-12-04 | VOC1 200429711 | ND |
| 2016-02-29 | VOC1 200434386 | ND |
| 2016-02-29 | VOC1 200434387 | ND |
| 2016-02-29 | VOC1 200434371 | ND |
| 2016-02-29 | VOC1 200434372 | ND |
| 2016-03-01 | VOC1 200434428 | ND |
| 2016-03-01 | VOC1 200434431 | ND |
| 2016-03-01 | VOC1 200434429 | ND |
| 2016-03-01 | VOC1 200434430 | ND |
| 2016-03-01 | VOC1 200434474 | ND |
| 2016-03-03 | VOC1 200434800 | ND |
| 2017-02-27 | VOC1 200461301 | ND |
| 2017-02-27 | VOC1 200461317 | ND |
| 2017-02-27 | VOC1 200461316 | ND |
| 2017-02-28 | VOC1 200461369 | ND |
| 2017-02-28 | VOC1 200461372 | ND |
| 2017-02-28 | VOC1 200461370 | ND |
| 2017-02-28 | VOC1 200461371 | ND |
| 2017-02-28 | VOC1 200461405 | ND |
| 2017-02-28 | VOC1 200461407 | ND |
| 2017-03-02 | VOC1 200461633 | ND |
| 2017-06-19 | VOC1 200469687 | ND |
| 2017-06-19 | VOC1 200469688 | ND |
| 2018-03-05 | VOC1 200489156 | ND |
| 2018-03-05 | VOC1 200489128 | ND |
| 2018-03-05 | VOC1 200489129 | ND |
| 2018-03-05 | VOC1 200489150 | ND |
| 2018-03-06 | VOC1 200489298 | ND |
| 2018-03-06 | VOC1 200489296 | ND |
| 2018-03-06 | VOC1 200489295 | ND |
| 2018-08-17 | VOC1 200502735 | ND |
| 2018-11-29 | VOC1 200514106 | ND |
| 2018-11-29 | VOC1 200514121 | ND |
| 2019-03-04 | VOC1 200523150 | ND |
| 2019-03-04 | VOC1 200523151 | ND |
| 2019-03-04 | VOC1 200523175 | ND |
| 2019-03-04 | VOC1 200523176 | ND |
| 2019-03-05 | VOC1 200523251 | ND |
| 2019-03-05 | VOC1 200523254 | ND |
| 2019-03-05 | VOC1 200523252 | ND |
| 2019-03-05 | VOC1 200523253 | ND |
| 2019-03-05 | VOC1 200523284 | ND |
| 2019-03-05 | VOC1 200523286 | ND |
| 2019-05-08 | VOC1 200531298 | ND |