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 |
|---|---|---|---|---|
| 2018 | ND | 5 | 0 | ND |
| 2019 | ND | 12 | 0 | ND |
| 2020 | ND | 12 | 0 | ND |
| 2021 | ND | 13 | 0 | ND |
| 2022 | ND | 15 | 0 | ND |
| 2023 | ND | 12 | 0 | ND |
ppb = parts per billion
State, National, and Health Guidelines for Drinking Water
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 |
|---|---|---|
| 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 |
| 2020-01-06 | TOC 200561542 | ND |
| 2020-02-03 | TOC 200564470 | ND |
| 2020-03-02 | TOC 200567648 | ND |
| 2020-04-07 | TOC 200571565 | ND |
| 2020-05-05 | DBP 200574520 | ND |
| 2020-06-02 | TOC 200577581 | ND |
| 2020-07-07 | TOC 200581392 | ND |
| 2020-08-04 | TOC 200584914 | ND |
| 2020-09-01 | TOC 200588254 | ND |
| 2020-10-06 | TOC 200592560 | ND |
| 2020-11-03 | TOC 200596644 | ND |
| 2020-12-01 | TOC 200599368 | ND |
| 2021-01-05 | TOC 200602429 | ND |
| 2021-02-02 | TOC 200605159 | ND |
| 2021-03-02 | TOC 200608307 | ND |
| 2021-04-06 | TOC 200611935 | ND |
| 2021-05-04 | TOC 200615344 | ND |
| 2021-06-01 | TOC 200618710 | ND |
| 2021-07-07 | TOC 200623212 | ND |
| 2021-10-18 | O300082886 300082887 | ND |
| 2021-10-18 | O300082882 300082883 | ND |
| 2021-11-01 | O300091732 300091733 | ND |
| 2021-11-01 | O300091728 300091729 | ND |
| 2021-12-01 | O300109971 300109972 | ND |
| 2021-12-01 | O300109967 300109968 | ND |
| 2022-01-06 | O300128605 300128606 | ND |
| 2022-01-06 | O300128601 300128602 | ND |
| 2022-02-02 | O300152370 300152373 | ND |
| 2022-02-02 | O300152375 300152377 | ND |
| 2022-03-01 | O300151283 300151284 | ND |
| 2022-03-01 | O300151278 300151279 | ND |
| 2022-04-04 | O300165197 300165201 | ND |
| 2022-05-03 | O300177546 300177550 | ND |
| 2022-06-01 | O300191291 300191295 | ND |
| 2022-07-06 | O300207940 300207944 | ND |
| 2022-08-03 | O300223826 300223830 | ND |
| 2022-09-06 | O300238794 300238798 | ND |
| 2022-10-03 | O300252720 300252724 | ND |
| 2022-11-03 | O300266994 300266998 | ND |
| 2022-12-05 | O300280229 300280233 | ND |
| 2023-01-04 | O300292376 300292380 | ND |
| 2023-02-01 | O300303452 300303456 | ND |
| 2023-03-01 | O300314993 300314997 | ND |
| 2023-04-03 | O300327029 300327033 | ND |
| 2023-05-01 | O300341327 300341331 | ND |
| 2023-06-01 | O300357010 300357014 | ND |
| 2023-07-10 | O300378219 300378223 | ND |
| 2023-08-01 | O300389633 300389637 | ND |
| 2023-09-06 | O300410234 300410238 | ND |
| 2023-10-03 | O300423857 300423861 | ND |
| 2023-11-01 | O300438943 300438947 | ND |
| 2023-12-06 | O300455289 300455293 | ND |