Bromodichloromethane

California Water Service - San Mateo

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

192

Samples

Samples exceeding legal limit (MCL)

173

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2014	1.52 ppb	32	31	ND - 4.55 ppb
2015	3.23 ppb	32	31	ND - 8.02 ppb
2016	3.35 ppb	32	32	0.720 ppb - 11.0 ppb
2017	2.37 ppb	32	24	ND - 4.61 ppb
2018	1.94 ppb	32	31	ND - 5.23 ppb
2019	1.26 ppb	32	24	ND - 4.02 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
2014-02-05	5701-900-1205	2.90 ppb
2014-02-05	5701-901-1120	1.51 ppb
2014-02-05	5701-902-1105	1.43 ppb
2014-02-05	5701-903-0945	4.36 ppb
2014-02-05	5701-904-1140	1.50 ppb
2014-02-05	5701-905-1000	4.55 ppb
2014-02-05	5701-906-1020	1.71 ppb
2014-02-05	5701-907-1225	3.41 ppb
2014-05-07	5701-900-1515	0.840 ppb
2014-05-07	5701-901-1545	0.960 ppb
2014-05-07	5701-902-1600	ND
2014-05-07	5701-903-1540	0.840 ppb
2014-05-07	5701-904-1705	0.950 ppb
2014-05-07	5701-905-1600	0.890 ppb
2014-05-07	5701-906-1434	0.900 ppb
2014-05-07	5701-907-1455	0.940 ppb
2014-08-06	5701-900-1300	1.04 ppb
2014-08-06	5701-901-1100	1.12 ppb
2014-08-06	5701-902-1115	1.12 ppb
2014-08-06	5701-903-1250	0.990 ppb
2014-08-06	5701-904-1025	1.11 ppb
2014-08-06	5701-905-1305	0.990 ppb
2014-08-06	5701-906-1140	1.14 ppb
2014-08-06	5701-907-1355	1.01 ppb
2014-11-03	5701-900-1300	1.45 ppb
2014-11-03	5701-901-1245	1.48 ppb
2014-11-03	5701-902-1230	1.61 ppb
2014-11-03	5701-903-1150	1.45 ppb
2014-11-03	5701-904-1350	1.72 ppb
2014-11-03	5701-905-1125	1.44 ppb
2014-11-03	5701-906-1335	1.64 ppb
2014-11-03	5701-907-1320	1.50 ppb
2015-02-04	5701-900-0850	6.90 ppb
2015-02-04	5701-901-0850	7.45 ppb
2015-02-04	5701-902-0850	7.86 ppb
2015-02-04	5701-903-0850	6.17 ppb
2015-02-04	5701-904-0850	8.02 ppb
2015-02-04	5701-905-0850	6.17 ppb
2015-02-04	5701-906-0850	7.73 ppb
2015-02-04	5701-907-0850	6.84 ppb
2015-05-06	5701-900-0832	0.890 ppb
2015-05-06	5701-901-0832	1.03 ppb
2015-05-06	5701-902-0832	0.950 ppb
2015-05-06	5701-903-0832	0.770 ppb
2015-05-06	5701-904-0832	0.970 ppb
2015-05-06	5701-905-0832	0.850 ppb
2015-05-06	5701-906-0832	ND
2015-05-06	5701-907-0832	0.940 ppb
2015-08-04	5701-900-0827	1.11 ppb
2015-08-04	5701-901-0827	1.20 ppb
2015-08-04	5701-902-0827	1.25 ppb
2015-08-04	5701-903-0827	1.08 ppb
2015-08-04	5701-904-0827	1.22 ppb
2015-08-04	5701-905-0827	1.09 ppb
2015-08-04	5701-906-0827	1.24 ppb
2015-08-04	5701-907-0827	1.24 ppb
2015-11-03	5701-900-0818	3.37 ppb
2015-11-03	5701-901-0818	4.59 ppb
2015-11-03	5701-902-0818	4.45 ppb
2015-11-03	5701-903-0818	3.39 ppb
2015-11-03	5701-904-0818	4.77 ppb
2015-11-03	5701-905-0818	3.44 ppb
2015-11-03	5701-906-0818	4.73 ppb
2015-12-09	5810-907-0840	1.80 ppb
2016-02-02	5701-900-0858	8.24 ppb
2016-02-02	5701-901-0858	11.0 ppb
2016-02-02	5701-902-0858	10.7 ppb
2016-02-02	5701-903-0858	6.74 ppb
2016-02-02	5701-904-0858	11.0 ppb
2016-02-02	5701-905-0858	6.26 ppb
2016-02-02	5701-906-0858	10.1 ppb
2016-02-02	5701-907-0858	8.74 ppb
2016-05-02	5701-900-0714	2.43 ppb
2016-05-02	5701-901-0714	2.04 ppb
2016-05-02	5701-902-0714	2.14 ppb
2016-05-02	5701-903-0714	2.34 ppb
2016-05-02	5701-904-0714	2.10 ppb
2016-05-02	5701-905-0714	2.33 ppb
2016-05-02	5701-906-0714	2.27 ppb
2016-05-02	5701-907-0714	2.16 ppb
2016-08-02	5701-900-0856	0.720 ppb
2016-08-02	5701-901-0856	0.750 ppb
2016-08-02	5701-902-0856	0.980 ppb
2016-08-02	5701-903-0856	0.750 ppb
2016-08-02	5701-904-0856	0.900 ppb
2016-08-02	5701-905-0856	0.750 ppb
2016-08-02	5701-906-0856	0.970 ppb
2016-08-02	5701-907-0856	0.980 ppb
2016-11-07	5701-900-0931	1.13 ppb
2016-11-07	5701-901-0931	1.30 ppb
2016-11-07	5701-902-0931	1.29 ppb
2016-11-07	5701-903-0931	1.23 ppb
2016-11-07	5701-904-0931	1.35 ppb
2016-11-07	5701-905-0931	1.24 ppb
2016-11-07	5701-906-0931	1.32 ppb
2016-11-09	5701-907-0844	1.21 ppb
2017-02-06	5701-900-0653	4.61 ppb
2017-02-06	5701-901-0653	3.78 ppb
2017-02-06	5701-902-0653	3.77 ppb
2017-02-06	5701-903-0653	4.24 ppb
2017-02-06	5701-904-0654	3.52 ppb
2017-02-06	5701-905-0654	4.32 ppb
2017-02-06	5701-906-0654	3.94 ppb
2017-02-06	5701-907-0654	3.34 ppb
2017-05-01	5810-900-1510	2.40 ppb
2017-05-01	5810-901-1100	3.10 ppb
2017-05-01	5810-902-1145	3.00 ppb
2017-05-01	5810-903-1440	2.20 ppb
2017-05-01	5810-904-1115	3.10 ppb
2017-05-01	5810-905-1455	2.40 ppb
2017-05-01	5810-906-1030	3.10 ppb
2017-05-01	5810-907-1045	2.50 ppb
2017-08-09	5810-900-0820	ND
2017-08-09	5810-901-1140	ND
2017-08-09	5810-902-1150	ND
2017-08-09	5810-903-1315	ND
2017-08-09	5810-904-0740	ND
2017-08-09	5810-905-1300	ND
2017-08-09	5810-906-1205	ND
2017-08-09	5810-907-0900	ND
2017-11-08	5701-900-0904	1.91 ppb
2017-11-08	5701-901-0904	3.75 ppb
2017-11-08	5701-902-0904	2.85 ppb
2017-11-08	5701-903-0904	1.80 ppb
2017-11-08	5701-904-0904	3.13 ppb
2017-11-08	5701-905-0904	1.95 ppb
2017-11-08	5701-906-0904	3.62 ppb
2017-11-08	5701-907-0904	3.37 ppb
2018-02-05	5810-900-1250	1.000 ppb
2018-02-05	5810-901-1220	2.30 ppb
2018-02-05	5810-902-1205	2.30 ppb
2018-02-05	5810-903-1020	1.000 ppb
2018-02-05	5810-904-1235	2.60 ppb
2018-02-05	5810-905-1315	ND
2018-02-05	5810-906-0935	2.40 ppb
2018-02-05	5810-907-0955	1.30 ppb
2018-05-07	5701-900-0852	1.38 ppb
2018-05-07	5701-901-0852	1.61 ppb
2018-05-07	5701-902-0852	1.52 ppb
2018-05-07	5701-903-0852	1.46 ppb
2018-05-07	5701-904-0852	1.60 ppb
2018-05-07	5701-905-0852	1.57 ppb
2018-05-07	5701-906-0852	1.63 ppb
2018-05-07	5701-907-0852	1.47 ppb
2018-08-06	5701-900-0809	0.690 ppb
2018-08-06	5701-901-0809	0.830 ppb
2018-08-06	5701-902-0809	0.880 ppb
2018-08-06	5701-903-0809	0.760 ppb
2018-08-06	5701-904-0809	0.890 ppb
2018-08-06	5701-905-0809	0.810 ppb
2018-08-06	5701-906-0809	0.850 ppb
2018-08-06	5701-907-0809	0.850 ppb
2018-11-05	5701-900-1021	1.95 ppb
2018-11-05	5701-901-1021	4.58 ppb
2018-11-05	5701-902-1021	4.73 ppb
2018-11-05	5701-903-1021	2.65 ppb
2018-11-05	5701-904-1021	4.93 ppb
2018-11-05	5701-905-1021	3.10 ppb
2018-11-05	5701-906-1021	5.23 ppb
2018-11-05	5701-907-1021	3.05 ppb
2019-02-06	5701-900-0623	3.25 ppb
2019-02-06	5701-901-0623	4.02 ppb
2019-02-06	5701-902-0623	3.62 ppb
2019-02-06	5701-903-0623	2.97 ppb
2019-02-06	5701-904-0623	3.27 ppb
2019-02-06	5701-905-0623	2.91 ppb
2019-02-06	5701-906-0623	3.46 ppb
2019-02-06	5701-907-0623	3.33 ppb
2019-05-07	5701-900-0858	0.990 ppb
2019-05-07	5701-901-0858	1.000 ppb
2019-05-07	5701-902-0858	1.000 ppb
2019-05-07	5701-903-0858	1.03 ppb
2019-05-07	5701-904-0858	1.02 ppb
2019-05-07	5701-905-0858	0.990 ppb
2019-05-07	5701-906-0858	0.980 ppb
2019-05-07	5701-907-0858	1.000 ppb
2019-08-06	5701-900-0820	0.640 ppb
2019-08-06	5701-901-1000	0.640 ppb
2019-08-06	5701-902-1010	0.650 ppb
2019-08-06	5701-903-0745	0.700 ppb
2019-08-06	5701-904-0940	0.690 ppb
2019-08-06	5701-905-0800	0.680 ppb
2019-08-06	5701-906-1030	0.740 ppb
2019-08-06	5701-907-0835	0.670 ppb
2019-11-05	5701-900-1145	ND
2019-11-05	5701-901-0915	ND
2019-11-05	5701-902-0925	ND
2019-11-05	5701-903-1125	ND
2019-11-05	5701-904-0855	ND
2019-11-05	5701-905-1130	ND
2019-11-05	5701-906-1215	ND
2019-11-05	5701-907-1200	ND