Bromate
Regional Water Authority
Bromate is a carcinogenic disinfection byproduct formed when source waters containing bromide are treated with ozonation or sodium hypochlorite. Studies of laboratory animals show that bromate damages DNA and causes cancer in multiple organs. Click here to read more about disinfection byproducts.
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 | 13 | 0 | ND |
| 2015 | ND | 12 | 0 | ND |
| 2016 | ND | 12 | 0 | ND |
| 2017 | ND | 6 | 0 | ND |
| 2018 | ND | 5 | 0 | ND |
| 2019 | ND | 12 | 0 | ND |
ppb = parts per billion
State and national drinking water standards and health guidelines
EWG Health Guideline 0.1 ppb
The EWG Health Guideline of 0.1 ppb for bromate 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) 10 ppb
The legal limit for bromate, established in 1998, 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 bromate exposure.
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2014-01-15 | DPB 200389454 | ND |
| 2014-02-04 | DBP 200390409 | ND |
| 2014-03-04 | DPB 200391995 | ND |
| 2014-03-04 | 200391995 | ND |
| 2014-04-01 | DPB 200393370 | ND |
| 2014-05-06 | DBP 200395293 | ND |
| 2014-06-03 | DBP 200397008 | ND |
| 2014-07-07 | DBP 200399026 | ND |
| 2014-08-08 | DPB 200401446 | ND |
| 2014-09-02 | DPB 200403296 | ND |
| 2014-10-14 | DPB 200406043 | ND |
| 2014-11-04 | DBP 200407288 | ND |
| 2014-12-03 | DBP 200408847 | ND |
| 2015-01-13 | DPB 200410536 | ND |
| 2015-02-03 | DBP 200411390 | ND |
| 2015-03-04 | DPB 200413026 | ND |
| 2015-04-07 | DPB 200414524 | ND |
| 2015-05-05 | DBP 200416180 | ND |
| 2015-06-03 | DBP 200417818 | ND |
| 2015-07-07 | DBP 200419805 | ND |
| 2015-08-12 | DBP 200422444 | ND |
| 2015-09-02 | DBP 200424005 | ND |
| 2015-10-07 | DBP 200426287 | ND |
| 2015-11-04 | DBP 200428096 | ND |
| 2015-12-02 | DBP 200429583 | ND |
| 2016-01-07 | DBP 200431542 | ND |
| 2016-02-03 | DBP 200433035 | ND |
| 2016-03-03 | DBP 200434713 | ND |
| 2016-04-05 | DBP 200436454 | ND |
| 2016-05-03 | DBP 200438533 | ND |
| 2016-06-02 | DBP 200441244 | ND |
| 2016-07-06 | DBP 200443787 | ND |
| 2016-08-03 | DBP 200446204 | ND |
| 2016-09-07 | DBP 200449149 | ND |
| 2016-10-04 | DBP 200451495 | ND |
| 2016-11-01 | DBP 200453587 | ND |
| 2016-12-07 | DBP 200456388 | ND |
| 2017-01-04 | DBP 200457960 | ND |
| 2017-03-30 | DBP 200463432 | ND |
| 2017-04-04 | DBP 200463663 | ND |
| 2017-05-02 | DBP 200465725 | ND |
| 2017-06-07 | DBP 200468664 | ND |
| 2017-07-05 | DBP 200471068 | ND |
| 2018-08-17 | DBP 200502735 | ND |
| 2018-09-04 | DBP 200503766 | ND |
| 2018-10-01 | DBP 200507184 | ND |
| 2018-11-05 | DBP 200511249 | ND |
| 2018-12-03 | DBP 200514365 | ND |
| 2019-01-02 | DBP 200517167 | ND |
| 2019-02-04 | DBP 200520183 | ND |
| 2019-03-04 | DBP 200523183 | ND |
| 2019-04-01 | DBP 200526356 | ND |
| 2019-05-02 | DBP 200530377 | ND |
| 2019-06-03 | DBP 200534442 | ND |
| 2019-07-01 | DBP 200538405 | ND |
| 2019-08-08 | DBP 200543882 | ND |
| 2019-09-04 | DBP 200547183 | ND |
| 2019-10-01 | DBP 200550743 | ND |
| 2019-11-29 | DBP 200558323 | ND |
| 2019-12-16 | TOC 200560325 | ND |