Bromodichloromethane
Carson
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 |
|---|---|---|---|---|
| 2014 | 0.655 ppb | 2 | 2 | 0.630 ppb - 0.680 ppb |
| 2015 | 0.650 ppb | 2 | 2 | 0.580 ppb - 0.720 ppb |
| 2016 | ND | 4 | 0 | ND |
| 2017 | 0.933 ppb | 4 | 4 | 0.720 ppb - 1.30 ppb |
| 2018 | 0.550 ppb | 1 | 1 | 0.550 ppb |
| 2019 | 0.483 ppb | 3 | 2 | ND - 0.760 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 | Lab ID | Result |
|---|---|---|
| 2014-03-19 | 20087 | 0.680 ppb |
| 2014-06-09 | 79901 | 0.630 ppb |
| 2015-04-08 | 14301 | 0.720 ppb |
| 2015-08-20 | 39101 | 0.580 ppb |
| 2016-05-09 | ND | |
| 2016-08-08 | ND | |
| 2016-09-13 | ND | |
| 2016-11-17 | ND | |
| 2017-06-26 | 0.780 ppb | |
| 2017-08-07 | 0.930 ppb | |
| 2017-11-07 | 1.30 ppb | |
| 2017-12-28 | 0.720 ppb | |
| 2018-03-06 | 0.550 ppb | |
| 2019-03-04 | 0.760 ppb | |
| 2019-11-18 | 0.690 ppb | |
| 2019-11-18 | ND |