Bromodichloromethane

Harwich Water Department

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.

MORE ABOUT THIS CONTAMINANT

120

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	0.114 ppb	14	1	ND - 1.60 ppb
2015	0.270 ppb	18	4	ND - 2.00 ppb
2016	0.250 ppb	18	3	ND - 2.20 ppb
2017	0.275 ppb	26	5	ND - 2.70 ppb
2018	0.660 ppb	25	6	ND - 4.60 ppb
2019	0.247 ppb	19	3	ND - 2.00 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
2014-02-27	ND
2014-02-27	ND
2014-02-27	ND
2014-02-27	ND
2014-02-27	ND
2014-02-27	ND
2014-03-05	1.60 ppb
2014-03-06	ND
2014-03-06	ND
2014-03-06	ND
2014-03-06	ND
2014-03-06	ND
2014-03-06	ND
2014-03-06	ND
2015-02-25	ND
2015-02-25	ND
2015-02-25	ND
2015-02-25	ND
2015-02-25	ND
2015-02-25	ND
2015-02-26	ND
2015-02-26	ND
2015-02-26	ND
2015-02-26	ND
2015-02-26	ND
2015-02-26	ND
2015-02-26	ND
2015-03-13	2.00 ppb
2015-08-12	0.790 ppb
2015-08-12	1.20 ppb
2015-08-12	ND
2015-08-12	0.870 ppb
2016-02-29	ND
2016-02-29	ND
2016-02-29	1.20 ppb
2016-02-29	ND
2016-02-29	ND
2016-03-02	ND
2016-03-02	ND
2016-03-02	ND
2016-03-02	ND
2016-03-02	ND
2016-03-02	ND
2016-03-02	ND
2016-03-23	ND
2016-03-23	ND
2016-08-24	1.10 ppb
2016-08-24	2.20 ppb
2016-08-24	ND
2016-08-24	ND
2017-02-28	ND
2017-02-28	ND
2017-03-09	ND
2017-03-09	ND
2017-03-09	ND
2017-03-09	ND
2017-03-09	ND
2017-03-09	ND
2017-03-09	ND
2017-03-09	ND
2017-03-09	ND
2017-03-09	0.770 ppb
2017-03-09	0.680 ppb
2017-03-09	ND
2017-05-17	ND
2017-05-17	ND
2017-06-07	ND
2017-08-09	ND
2017-08-09	ND
2017-08-10	1.000 ppb
2017-08-10	2.70 ppb
2017-08-10	ND
2017-08-10	2.00 ppb
2017-12-20	ND
2017-12-21	ND
2017-12-21	ND
2018-03-08	ND
2018-03-08	ND
2018-03-08	ND
2018-03-08	ND
2018-03-08	ND
2018-03-08	ND
2018-03-08	ND
2018-03-08	ND
2018-03-08	ND
2018-03-08	ND
2018-03-08	ND
2018-03-08	ND
2018-05-16	3.10 ppb
2018-05-16	3.00 ppb
2018-05-16	4.60 ppb
2018-08-14	ND
2018-08-14	1.60 ppb
2018-08-15	3.20 ppb
2018-08-15	1.000 ppb
2018-08-15	ND
2018-08-15	ND
2018-08-22	ND
2018-12-10	ND
2018-12-10	ND
2018-12-10	ND
2019-03-06	ND
2019-03-06	ND
2019-03-06	ND
2019-03-06	ND
2019-03-07	ND
2019-03-07	ND
2019-06-19	ND
2019-06-19	ND
2019-06-19	ND
2019-08-15	ND
2019-08-15	ND
2019-08-15	ND
2019-08-19	ND
2019-08-19	1.50 ppb
2019-08-26	2.00 ppb
2019-08-26	1.20 ppb
2019-12-04	ND
2019-12-04	ND
2019-12-04	ND