Dibromochloromethane

Dover Water Commission

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.

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144

Samples

Samples exceeding legal limit (MCL)

134

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2014	2.40 ppb	24	21	ND - 6.68 ppb
2015	2.93 ppb	24	24	0.530 ppb - 7.15 ppb
2016	2.68 ppb	24	20	ND - 5.75 ppb
2017	3.07 ppb	24	23	ND - 5.98 ppb
2018	3.58 ppb	24	23	ND - 10.1 ppb
2019	2.49 ppb	24	23	ND - 4.76 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
2014-01-15	25051-4	2.56 ppb
2014-01-15	25051-3	2.31 ppb
2014-01-15	25051-2	2.65 ppb
2014-01-15	25051-1	2.58 ppb
2014-03-05	25734-2A	0.500 ppb
2014-03-05	25734-1A	0.750 ppb
2014-04-16	26316-4	2.55 ppb
2014-04-16	26316-3	4.81 ppb
2014-04-16	26316-2	2.16 ppb
2014-04-16	26316-1	2.83 ppb
2014-06-18	27310-2	0.840 ppb
2014-06-18	27310-1	0.990 ppb
2014-07-16	27840-4	4.76 ppb
2014-07-16	27840-3	6.68 ppb
2014-07-16	27840-2	2.95 ppb
2014-07-16	27840-1	4.86 ppb
2014-09-26	29140-2B	ND
2014-09-26	29140-1B	0.720 ppb
2014-10-16	29456-4	1.71 ppb
2014-10-16	29456-3	6.55 ppb
2014-10-16	29456-2	2.03 ppb
2014-10-16	29456-1	1.92 ppb
2014-12-10	30311-17	ND
2014-12-10	30311-16	ND
2015-01-15	30804-4	1.90 ppb
2015-01-15	30804-3	4.58 ppb
2015-01-15	30804-2	1.94 ppb
2015-01-15	30804-1	2.12 ppb
2015-01-29	30990-2	0.660 ppb
2015-01-29	30990-1	1.09 ppb
2015-04-16	DWS242-4	2.02 ppb
2015-04-16	DWS242-3	5.06 ppb
2015-04-16	DWS242-2	2.23 ppb
2015-04-16	DWS242-1	3.46 ppb
2015-04-16	DWS243-2	0.580 ppb
2015-04-16	DWS243-1	0.530 ppb
2015-07-14	DWS1151-4	5.15 ppb
2015-07-14	DWS1151-3	6.76 ppb
2015-07-14	DWS1151-2	2.66 ppb
2015-07-14	DWS1151-1	6.93 ppb
2015-09-10	DWS1518-2A	0.560 ppb
2015-09-10	DWS1518-1A	1.36 ppb
2015-10-15	DWS1754-3	3.42 ppb
2015-10-15	DWS1754-2	7.15 ppb
2015-10-15	DWS1754-1	4.08 ppb
2015-10-21	DWS1794-1	3.58 ppb
2015-11-18	DWS1964-2	0.550 ppb
2015-11-18	DWS1964-1	2.03 ppb
2016-01-20	DWS2269-2	ND
2016-01-20	DWS2269-1	ND
2016-01-22	DWS2284-4	2.05 ppb
2016-01-22	DWS2284-3	4.60 ppb
2016-01-22	DWS2284-2	4.07 ppb
2016-01-22	DWS2284-1	3.72 ppb
2016-04-15	DWS2805-4	2.21 ppb
2016-04-15	DWS2805-3	3.64 ppb
2016-04-15	DWS2805-2	2.84 ppb
2016-04-15	DWS2805-1	1.91 ppb
2016-04-20	DWS2860-2A	ND
2016-04-20	DWS2860-1A	0.660 ppb
2016-07-11	DWS3345-2	0.980 ppb
2016-07-11	DWS3345-1	0.940 ppb
2016-07-20	DWS3396-4	3.65 ppb
2016-07-20	DWS3396-3	2.32 ppb
2016-07-20	DWS3396-2	4.22 ppb
2016-07-20	DWS3396-1	5.19 ppb
2016-10-12	DWS3996-4	5.12 ppb
2016-10-12	DWS3996-3	5.75 ppb
2016-10-12	DWS3996-2	5.27 ppb
2016-10-12	DWS3996-1	4.66 ppb
2016-12-09	DWS4357-2A	ND
2016-12-09	DWS4357-1A	0.510 ppb
2017-01-20	DWS4623-4	2.26 ppb
2017-01-20	DWS4623-3	3.14 ppb
2017-01-20	DWS4623-2	3.11 ppb
2017-01-20	DWS4623-1	2.81 ppb
2017-03-02	DWS4896-2A	ND
2017-03-02	DWS4896-1A	0.670 ppb
2017-04-28	DWS5304-4	4.84 ppb
2017-04-28	DWS5304-3	5.98 ppb
2017-04-28	DWS5304-2	5.86 ppb
2017-04-28	DWS5304-1	5.12 ppb
2017-05-02	DWS5334-2	0.660 ppb
2017-05-02	DWS5334-1	0.770 ppb
2017-07-17	DWS5949-4	3.43 ppb
2017-07-17	DWS5949-3	4.99 ppb
2017-07-17	DWS5949-2	3.42 ppb
2017-07-17	DWS5949-1	5.52 ppb
2017-07-31	DWS6081-2	0.600 ppb
2017-07-31	DWS6081-1	0.850 ppb
2017-10-06	DWS6722-2	1.07 ppb
2017-10-06	DWS6722-1	1.50 ppb
2017-10-16	DWS6821-4	3.81 ppb
2017-10-16	DWS6821-3	5.00 ppb
2017-10-16	DWS6821-2	4.48 ppb
2017-10-16	DWS6821-1	3.68 ppb
2018-01-16	DWS7566-4	2.51 ppb
2018-01-16	DWS7566-3	3.26 ppb
2018-01-16	DWS7566-2	4.29 ppb
2018-01-16	DWS7566-1	2.58 ppb
2018-02-02	DWS7708-2A	0.510 ppb
2018-02-02	DWS7708-1A	1.02 ppb
2018-04-16	DWS8383-4	4.42 ppb
2018-04-16	DWS8383-3	4.13 ppb
2018-04-16	DWS8383-2	6.37 ppb
2018-04-16	DWS8383-1	10.1 ppb
2018-04-26	DWS8495-1	0.980 ppb
2018-04-26	DWS8494-1	1.42 ppb
2018-07-06	18070509-02	0.720 ppb
2018-07-06	18070509-01	0.860 ppb
2018-07-16	18071320-04	4.74 ppb
2018-07-16	18071320-03	4.62 ppb
2018-07-16	18071320-02	5.63 ppb
2018-07-16	18071320-01	5.32 ppb
2018-10-16	18101510-04	3.93 ppb
2018-10-16	18101510-03	6.67 ppb
2018-10-16	18101510-02	5.65 ppb
2018-10-16	18101510-01	5.11 ppb
2018-11-02	18110119-02	ND
2018-11-02	18110119-01	1.01 ppb
2019-01-09	19010837-02	1.33 ppb
2019-01-09	19010837-01	0.630 ppb
2019-01-15	19011412-04	3.09 ppb
2019-01-15	19011412-03	4.34 ppb
2019-01-15	19011412-02	4.74 ppb
2019-01-15	19011412-01	2.65 ppb
2019-04-17	19041618-04	3.16 ppb
2019-04-17	19041618-03	4.63 ppb
2019-04-17	19041618-02	4.23 ppb
2019-04-17	19041618-01	3.42 ppb
2019-04-17	19041620-02	ND
2019-04-17	19041620-01	0.590 ppb
2019-07-05	19070333-002	0.690 ppb
2019-07-05	19070333-001	1.57 ppb
2019-07-15	19071230-004	1.29 ppb
2019-07-15	19071230-003	2.25 ppb
2019-07-15	19071230-002	1.40 ppb
2019-07-15	19071230-001	2.91 ppb
2019-10-17	19101609-004	3.63 ppb
2019-10-17	19101609-003	4.76 ppb
2019-10-17	19101609-002	3.13 ppb
2019-10-17	19101609-001	2.54 ppb
2019-11-01	19103136-002	0.620 ppb
2019-11-01	19103136-001	2.11 ppb