Bromodichloromethane
Mt Werner WD
Bromodichloromethane, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Bromodichloromethane and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. 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 |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | N/A | 0 | 0 | N/A |
| 2015 | 1.29 ppb | 7 | 7 | 0.650 ppb - 1.90 ppb |
| 2016 | 1.38 ppb | 10 | 10 | 0.570 ppb - 4.70 ppb |
| 2017 | 1.16 ppb | 10 | 10 | 0.630 ppb - 2.80 ppb |
| 2018 | 1.12 ppb | 18 | 18 | 0.560 ppb - 3.10 ppb |
| 2019 | 1.64 ppb | 18 | 18 | 0.530 ppb - 4.60 ppb |
ppb = parts per billion
State and national drinking water standards and health guidelines
EWG Health Guideline 0.06 ppb
The EWG Health Guideline of 0.06 ppb for bromodichloromethane was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
ppb = parts per billion
All test results
| Date | Result |
|---|---|
| 2015-05-20 | 0.870 ppb |
| 2015-05-20 | 0.650 ppb |
| 2015-08-25 | 1.60 ppb |
| 2015-08-25 | 1.10 ppb |
| 2015-11-03 | 1.000 ppb |
| 2015-11-03 | 1.90 ppb |
| 2015-11-03 | 1.90 ppb |
| 2016-02-23 | 1.20 ppb |
| 2016-02-23 | 0.930 ppb |
| 2016-05-03 | 1.20 ppb |
| 2016-05-03 | 1.50 ppb |
| 2016-05-03 | 1.10 ppb |
| 2016-08-11 | 4.70 ppb |
| 2016-08-24 | 0.740 ppb |
| 2016-08-24 | 0.570 ppb |
| 2016-11-16 | 1.20 ppb |
| 2016-11-16 | 0.630 ppb |
| 2017-02-21 | 0.730 ppb |
| 2017-02-21 | 0.630 ppb |
| 2017-05-10 | 0.820 ppb |
| 2017-05-10 | 1.20 ppb |
| 2017-05-10 | 0.660 ppb |
| 2017-08-02 | 2.80 ppb |
| 2017-11-07 | 1.10 ppb |
| 2017-11-07 | 1.30 ppb |
| 2017-11-07 | 1.40 ppb |
| 2017-11-07 | 0.980 ppb |
| 2018-02-01 | 0.770 ppb |
| 2018-02-01 | 0.760 ppb |
| 2018-02-01 | 0.890 ppb |
| 2018-02-01 | 0.790 ppb |
| 2018-05-09 | 0.620 ppb |
| 2018-05-09 | 0.760 ppb |
| 2018-05-09 | 0.560 ppb |
| 2018-05-09 | 1.30 ppb |
| 2018-06-19 | 0.620 ppb |
| 2018-08-21 | 0.960 ppb |
| 2018-08-21 | 1.10 ppb |
| 2018-08-21 | 1.50 ppb |
| 2018-08-21 | 1.40 ppb |
| 2018-08-21 | 3.10 ppb |
| 2018-11-08 | 1.40 ppb |
| 2018-11-08 | 0.940 ppb |
| 2018-11-08 | 1.20 ppb |
| 2018-11-08 | 1.50 ppb |
| 2019-02-20 | 1.40 ppb |
| 2019-02-20 | 2.20 ppb |
| 2019-02-20 | 1.30 ppb |
| 2019-02-20 | 1.50 ppb |
| 2019-05-14 | 1.70 ppb |
| 2019-05-14 | 1.40 ppb |
| 2019-05-14 | 1.50 ppb |
| 2019-05-14 | 1.000 ppb |
| 2019-08-07 | 4.10 ppb |
| 2019-08-14 | 3.90 ppb |
| 2019-08-14 | 0.690 ppb |
| 2019-08-14 | 0.790 ppb |
| 2019-08-14 | 0.640 ppb |
| 2019-10-23 | 1.000 ppb |
| 2019-11-13 | 0.530 ppb |
| 2019-11-13 | 0.620 ppb |
| 2019-11-13 | 0.630 ppb |
| 2019-11-13 | 4.60 ppb |