Bromodichloromethane

City of Mountain View

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

197

Samples

Samples exceeding legal limit (MCL)

165

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2014	5.63 ppb	32	32	0.740 ppb - 19.0 ppb
2015	7.96 ppb	36	31	ND - 31.8 ppb
2016	7.34 ppb	32	22	ND - 28.2 ppb
2017	5.43 ppb	32	27	ND - 12.2 ppb
2018	5.94 ppb	33	27	ND - 16.7 ppb
2019	6.88 ppb	32	26	ND - 26.6 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
2014-01-30	1610-900-0945	1.45 ppb
2014-01-30	1610-901-1020	1.12 ppb
2014-01-30	1610-902-1005	1.07 ppb
2014-01-30	1610-903-1040	2.72 ppb
2014-01-30	1610-904-1140	1.30 ppb
2014-01-30	1610-905-1125	5.37 ppb
2014-01-30	1610-906-1055	4.83 ppb
2014-01-30	1610-907-1110	6.97 ppb
2014-05-07	1610-900-1000	0.800 ppb
2014-05-07	1610-901-1015	0.750 ppb
2014-05-07	1610-902-0950	0.810 ppb
2014-05-07	1610-903-0840	0.810 ppb
2014-05-07	1610-904-0930	0.740 ppb
2014-05-07	1610-905-0915	18.2 ppb
2014-05-07	1610-906-0850	19.0 ppb
2014-05-07	1610-907-0900	18.5 ppb
2014-08-06	1610-900-0955	2.35 ppb
2014-08-06	1610-901-1010	2.49 ppb
2014-08-06	1610-902-1020	2.20 ppb
2014-08-06	1610-903-1045	2.26 ppb
2014-08-06	1610-904-1130	2.23 ppb
2014-08-06	1610-905-1120	8.79 ppb
2014-08-06	1610-906-1100	8.78 ppb
2014-08-06	1610-907-1110	8.38 ppb
2014-11-05	1610-900-0920	5.31 ppb
2014-11-05	1610-901-0945	2.12 ppb
2014-11-05	1610-902-0935	2.46 ppb
2014-11-05	1610-903-0830	2.44 ppb
2014-11-05	1610-904-0730	2.42 ppb
2014-11-05	1610-905-0745	14.3 ppb
2014-11-05	1610-906-0800	14.9 ppb
2014-11-05	1610-907-0810	14.6 ppb
2015-02-20	1610-900-0830	4.36 ppb
2015-02-20	1610-901-0905	4.48 ppb
2015-02-20	1610-902-0845	5.47 ppb
2015-02-20	1610-903-0945	4.62 ppb
2015-02-20	1610-904-1040	4.26 ppb
2015-02-20	1610-905-1020	24.8 ppb
2015-02-20	1610-906-1000	31.8 ppb
2015-02-20	1610-907-1010	26.4 ppb
2015-03-10	1610-902-0940	2.60 ppb
2015-03-10	1610-905-0825	11.5 ppb
2015-03-10	1610-906-0840	12.1 ppb
2015-03-10	1610-907-0900	13.7 ppb
2015-05-13	1610-900-0805	ND
2015-05-13	1610-901-0825	ND
2015-05-13	1610-902-0840	1.21 ppb
2015-05-13	1610-903-0920	ND
2015-05-13	1610-904-1010	ND
2015-05-13	1610-905-0955	28.1 ppb
2015-05-13	1610-906-0930	28.4 ppb
2015-05-13	1610-907-0945	27.6 ppb
2015-08-13	1610-900-1015	1.11 ppb
2015-08-13	1610-901-1000	1.05 ppb
2015-08-13	1610-902-0950	1.03 ppb
2015-08-13	1610-903-0900	1.01 ppb
2015-08-13	1610-904-0845	ND
2015-08-13	1610-905-0810	6.52 ppb
2015-08-13	1610-906-0755	5.37 ppb
2015-08-13	1610-907-0745	8.05 ppb
2015-11-12	1610-900-0800	2.42 ppb
2015-11-12	1610-901-1110	2.49 ppb
2015-11-12	1610-902-0840	2.47 ppb
2015-11-12	1610-903-0910	2.95 ppb
2015-11-12	1610-904-1050	2.48 ppb
2015-11-12	1610-905-1020	6.25 ppb
2015-11-12	1610-906-0920	5.41 ppb
2015-11-12	1610-907-0940	6.64 ppb
2016-02-10	1610-900-1015	9.18 ppb
2016-02-10	1610-901-0955	9.35 ppb
2016-02-10	1610-902-0940	9.33 ppb
2016-02-10	1610-903-0920	10.9 ppb
2016-02-10	1610-904-0810	9.61 ppb
2016-02-10	1610-905-0830	27.0 ppb
2016-02-10	1610-906-0850	28.2 ppb
2016-02-10	1610-907-0905	27.7 ppb
2016-05-11	1610-900-0900	3.16 ppb
2016-05-11	1610-901-0915	3.18 ppb
2016-05-11	1610-902-0930	3.14 ppb
2016-05-11	1610-903-1140	3.22 ppb
2016-05-11	1610-904-1025	3.21 ppb
2016-05-11	1610-905-1040	10.7 ppb
2016-05-11	1610-906-1100	12.3 ppb
2016-05-11	1610-907-1110	11.4 ppb
2016-08-10	1610-900-0800	ND
2016-08-10	1610-901-0830	ND
2016-08-10	1610-902-0820	ND
2016-08-10	1610-903-0855	ND
2016-08-10	1610-904-0945	ND
2016-08-10	1610-905-0935	9.84 ppb
2016-08-10	1610-906-0930	9.57 ppb
2016-08-10	1610-907-0915	10.1 ppb
2016-11-09	1610-900-1055	ND
2016-11-09	1610-901-1035	ND
2016-11-09	1610-902-1045	ND
2016-11-09	1610-903-1000	ND
2016-11-09	1610-904-1110	ND
2016-11-09	1610-905-0925	7.92 ppb
2016-11-09	1610-906-0935	7.58 ppb
2016-11-09	1610-907-0945	8.52 ppb
2017-02-08	1610-900-0720	3.63 ppb
2017-02-08	1610-901-0740	4.22 ppb
2017-02-08	1610-902-0735	4.47 ppb
2017-02-08	1610-903-1030	4.34 ppb
2017-02-08	1610-904-0915	4.32 ppb
2017-02-08	1610-905-0935	11.6 ppb
2017-02-08	1610-906-0955	11.3 ppb
2017-02-08	1610-907-1010	12.2 ppb
2017-05-09	1610-900-0720	3.46 ppb
2017-05-09	1610-901-0740	3.60 ppb
2017-05-09	1610-902-0755	3.57 ppb
2017-05-09	1610-903-0820	3.85 ppb
2017-05-09	1610-904-0950	3.07 ppb
2017-05-09	1610-905-0930	6.65 ppb
2017-05-09	1610-906-0840	7.26 ppb
2017-05-09	1610-907-0915	7.10 ppb
2017-08-09	1610-900-0710	ND
2017-08-09	1610-901-0725	ND
2017-08-09	1610-902-0740	ND
2017-08-09	1610-903-0800	ND
2017-08-09	1610-904-0900	ND
2017-08-09	1610-905-0845	9.80 ppb
2017-08-09	1610-906-0830	9.30 ppb
2017-08-09	1610-907-0815	8.58 ppb
2017-11-07	1610-900-0820	4.03 ppb
2017-11-07	1610-901-0850	4.22 ppb
2017-11-07	1610-902-0840	4.07 ppb
2017-11-07	1610-903-0915	2.40 ppb
2017-11-07	1610-904-1015	3.78 ppb
2017-11-07	1610-905-1000	11.1 ppb
2017-11-07	1610-906-0945	10.9 ppb
2017-11-07	1610-907-0935	11.0 ppb
2018-02-14	1610-900-0710	1.53 ppb
2018-02-14	1610-901-0740	1.49 ppb
2018-02-14	1610-902-0755	1.55 ppb
2018-02-14	1610-903-0820	1.25 ppb
2018-02-14	1610-904-0930	1.34 ppb
2018-02-14	1610-905-0915	16.6 ppb
2018-02-14	1610-906-0855	14.8 ppb
2018-02-14	1610-907-0840	16.7 ppb
2018-05-09	1610-900-0750	1.63 ppb
2018-05-09	1610-901-0810	1.34 ppb
2018-05-09	1610-902-0820	1.50 ppb
2018-05-09	1610-903-0840	1.56 ppb
2018-05-09	1610-904-0950	1.39 ppb
2018-05-09	1610-905-0930	12.3 ppb
2018-05-09	1610-906-0910	13.0 ppb
2018-05-09	1610-907-0900	13.1 ppb
2018-08-08	1610-900-0715	ND
2018-08-08	1610-901-0730	ND
2018-08-08	1610-902-0740	ND
2018-08-08	1610-903-0800	ND
2018-08-08	1610-904-0900	ND
2018-08-08	1610-905-0840	14.8 ppb
2018-08-08	1610-906-0830	12.5 ppb
2018-08-08	1610-907-0815	14.1 ppb
2018-11-15	9590-900-0850	1.90 ppb
2018-11-15	9590-901-0910	1.70 ppb
2018-11-15	9590-902-0920	1.70 ppb
2018-11-15	9590-903-0940	2.30 ppb
2018-11-15	9590-904-1050	1.90 ppb
2018-11-15	9590-905-1040	14.0 ppb
2018-11-15	9590-906-1020	16.0 ppb
2018-11-15	9590-907-1010	14.0 ppb
2018-12-06	9590-014-1200	ND
2019-02-14	1610-900-0900	3.84 ppb
2019-02-14	1610-901-0915	4.08 ppb
2019-02-14	1610-902-0925	4.07 ppb
2019-02-14	1610-903-0945	3.95 ppb
2019-02-14	1610-904-1035	3.56 ppb
2019-02-14	1610-905-1025	23.7 ppb
2019-02-14	1610-906-1010	22.6 ppb
2019-02-14	1610-907-0955	26.6 ppb
2019-05-08	1610-900-0700	ND
2019-05-08	1610-901-0715	1.07 ppb
2019-05-08	1610-902-0730	ND
2019-05-08	1610-903-0800	ND
2019-05-08	1610-904-0910	ND
2019-05-08	1610-905-0840	12.3 ppb
2019-05-08	1610-906-0830	11.6 ppb
2019-05-08	1610-907-0820	13.5 ppb
2019-08-15	1610-900-0730	1.27 ppb
2019-08-15	1610-901-0740	1.34 ppb
2019-08-15	1610-902-0755	1.33 ppb
2019-08-15	1610-903-0815	1.15 ppb
2019-08-15	1610-904-0930	1.23 ppb
2019-08-15	1610-905-0910	14.1 ppb
2019-08-15	1610-906-0845	10.9 ppb
2019-08-15	1610-907-0830	15.0 ppb
2019-11-13	1610-900-0650	ND
2019-11-13	1610-901-0710	1.01 ppb
2019-11-13	1610-902-0725	1.000 ppb
2019-11-13	1610-903-0740	1.57 ppb
2019-11-13	1610-904-0840	ND
2019-11-13	1610-905-0830	13.5 ppb
2019-11-13	1610-906-0815	13.3 ppb
2019-11-13	1610-907-0800	12.6 ppb