Dibromochloromethane
Carlsbad Municipal Water System
Dibromochloromethane, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Dibromochloromethane 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 | ND | 4 | 0 | ND |
| 2015 | 0.934 ppb | 16 | 11 | ND - 2.47 ppb |
| 2016 | 1.14 ppb | 16 | 13 | ND - 3.10 ppb |
| 2017 | 1.50 ppb | 16 | 14 | ND - 5.31 ppb |
| 2018 | 1.49 ppb | 16 | 13 | ND - 6.51 ppb |
| 2019 | 0.795 ppb | 2 | 1 | ND - 1.59 ppb |
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 dibromochloromethane 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 |
|---|---|---|
| 2014-03-25 | 1403C46-001A | ND |
| 2014-03-25 | 1403C47-001A | ND |
| 2014-03-25 | 1403C48-001A | ND |
| 2014-03-25 | 1403A58-001A | ND |
| 2015-03-11 | 1503533-001A | ND |
| 2015-03-11 | 1503531-001A | ND |
| 2015-03-11 | 1503529-001A | ND |
| 2015-03-11 | 1503530-001A | ND |
| 2015-06-17 | 2015017901 | 1.50 ppb |
| 2015-06-17 | 2015017899 | 0.750 ppb |
| 2015-06-17 | 2015017905 | 1.30 ppb |
| 2015-06-17 | 2015017900 | 1.50 ppb |
| 2015-09-22 | 1509D84-001A | 1.33 ppb |
| 2015-09-22 | 1509D82-001A | 1.24 ppb |
| 2015-09-22 | 1509D87-001A | 0.940 ppb |
| 2015-09-22 | 1509D79-001A | 0.579 ppb |
| 2015-12-09 | 1512613-001A | 1.83 ppb |
| 2015-12-09 | 1512610-001A | ND |
| 2015-12-09 | 1512612-001A | 1.50 ppb |
| 2015-12-09 | 1512611-001A | 2.47 ppb |
| 2016-03-09 | 1603734-001A | 1.25 ppb |
| 2016-03-09 | 1603738-001A | 0.956 ppb |
| 2016-03-09 | 1603737-001A | 0.952 ppb |
| 2016-03-09 | 1603728-001A | 0.507 ppb |
| 2016-06-08 | 1606482-001A | 1.18 ppb |
| 2016-06-08 | 1606483-001A | 0.950 ppb |
| 2016-06-08 | 1606478-001A | 0.667 ppb |
| 2016-06-08 | 1606476-001A | ND |
| 2016-09-26 | 1609F29-001A | 3.10 ppb |
| 2016-09-26 | 1609G45-001 | 2.95 ppb |
| 2016-09-26 | 1609G44-001A | 1.78 ppb |
| 2016-09-26 | 1609G46-001 | ND |
| 2016-12-14 | 1612A73-001 | ND |
| 2016-12-14 | 1612A67-001 | 0.998 ppb |
| 2016-12-14 | 1612A69-001 | 1.72 ppb |
| 2016-12-14 | 1612A71-001 | 1.22 ppb |
| 2017-03-29 | 1703F05-001 | 1.37 ppb |
| 2017-03-29 | 1703F16-001 | 1.23 ppb |
| 2017-03-29 | 1703F15-001 | 1.21 ppb |
| 2017-03-29 | 1703F07-001 | ND |
| 2017-06-20 | 1706B39-001 | 4.91 ppb |
| 2017-06-20 | 1706B38-001 | 1.13 ppb |
| 2017-06-20 | 1706B32-001 | 0.967 ppb |
| 2017-06-20 | 1706B84-001 | 0.808 ppb |
| 2017-09-20 | 1709D26-001 | 1.05 ppb |
| 2017-09-20 | 1709D28-001 | 0.792 ppb |
| 2017-09-20 | 1709D27-001 | 1.000 ppb |
| 2017-09-20 | 1709D25-001 | 5.31 ppb |
| 2017-12-18 | 1712B71-001 | 1.95 ppb |
| 2017-12-18 | 1712B73-001 | 1.37 ppb |
| 2017-12-18 | 1712B75-001 | 0.971 ppb |
| 2017-12-18 | 1712B69-001 | ND |
| 2018-03-14 | 1803995-001 | 0.669 ppb |
| 2018-03-14 | 1803994-001 | 1.14 ppb |
| 2018-03-14 | 1803993-001 | 1.54 ppb |
| 2018-03-14 | 1803992-001 | 1.14 ppb |
| 2018-06-28 | 1806H84-001 | 5.69 ppb |
| 2018-06-28 | 1806H86-001 | 0.846 ppb |
| 2018-06-28 | 1806H89-001 | 0.901 ppb |
| 2018-06-28 | 1806H91-001 | ND |
| 2018-09-18 | 1809B32-001 | 6.51 ppb |
| 2018-09-18 | 1809B33-001 | 1.13 ppb |
| 2018-09-18 | 1809B34-001 | ND |
| 2018-09-18 | 1809B35-001 | 1.08 ppb |
| 2018-12-19 | 1812B88-001 | 1.10 ppb |
| 2018-12-19 | 1812B90-001 | 0.959 ppb |
| 2018-12-19 | 1812B85-001 | ND |
| 2018-12-19 | 1812B83-001 | 1.13 ppb |
| 2019-06-18 | 1906A44-001 | ND |
| 2019-09-10 | 1909788-001 | 1.59 ppb |