Dibromochloromethane
Norwalk Water Department
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.
Testing results - average by year
Year | Average result | Samples taken | Detections | Range of results |
---|---|---|---|---|
2013 | N/A | 0 | 0 | N/A |
2014 | 3.46 ppb | 28 | 15 | ND - 12.8 ppb |
2015 | 4.88 ppb | 44 | 29 | ND - 17.7 ppb |
2016 | 4.70 ppb | 44 | 28 | ND - 18.0 ppb |
2017 | 3.86 ppb | 44 | 25 | ND - 18.3 ppb |
2018 | 4.20 ppb | 40 | 27 | ND - 11.9 ppb |
2019 | 4.10 ppb | 43 | 32 | ND - 11.8 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 |
---|---|---|
2014-02-04 | 3761-800-0910 | 3.60 ppb |
2014-02-04 | 3761-801-0815 | 8.20 ppb |
2014-02-04 | 3761-802-0857 | 3.90 ppb |
2014-02-04 | 3761-803-0844 | 1.90 ppb |
2014-02-04 | 3761-804-1010 | 9.20 ppb |
2014-02-04 | 3761-805-0950 | 7.70 ppb |
2014-02-04 | 3761-806-0935 | 4.70 ppb |
2014-02-04 | 3761-807-0830 | ND |
2014-02-19 | 9588-002-1030 | ND |
2014-02-19 | 9588-003-1000 | ND |
2014-02-19 | 9588-012-0930 | ND |
2014-04-29 | 9588-002-1029 | ND |
2014-04-29 | 9588-003-1018 | ND |
2014-04-29 | 9588-012-0950 | ND |
2014-07-23 | 9588-002-1025 | ND |
2014-07-23 | 9588-003-1010 | ND |
2014-07-23 | 9588-012-0945 | ND |
2014-08-12 | 3761-800-0925 | 10.6 ppb |
2014-08-12 | 3761-801-0835 | 12.7 ppb |
2014-08-12 | 3761-802-0913 | 10.9 ppb |
2014-08-12 | 3761-803-0900 | 2.40 ppb |
2014-08-12 | 3761-804-1020 | 12.8 ppb |
2014-08-12 | 3761-805-1000 | 2.10 ppb |
2014-08-12 | 3761-806-0940 | 5.00 ppb |
2014-08-12 | 3761-807-0850 | 1.10 ppb |
2014-12-10 | 9588-002-1020 | ND |
2014-12-10 | 9588-003-0945 | ND |
2014-12-10 | 9588-012-0924 | ND |
2015-01-27 | 3761-800-0935 | 11.1 ppb |
2015-01-27 | 3761-801-0900 | 8.90 ppb |
2015-01-27 | 3761-802-0950 | 12.6 ppb |
2015-01-27 | 3761-803-0920 | 3.70 ppb |
2015-01-27 | 3761-804-1035 | 9.40 ppb |
2015-01-27 | 3761-805-1015 | 3.30 ppb |
2015-01-27 | 3761-806-1000 | 3.40 ppb |
2015-01-27 | 3761-807-1100 | 2.40 ppb |
2015-03-25 | 9588-002-0953 | ND |
2015-03-25 | 9588-003-0940 | ND |
2015-03-25 | 9588-012-0926 | ND |
2015-04-23 | 9588-002-1041 | ND |
2015-04-23 | 9588-003-1024 | ND |
2015-04-23 | 9588-012-0947 | ND |
2015-05-05 | 3761-800-0915 | 14.0 ppb |
2015-05-05 | 3761-801-0820 | 12.3 ppb |
2015-05-05 | 3761-802-0905 | 12.2 ppb |
2015-05-05 | 3761-803-0840 | 2.10 ppb |
2015-05-05 | 3761-804-1005 | 11.7 ppb |
2015-05-05 | 3761-805-0945 | 3.10 ppb |
2015-05-05 | 3761-806-0930 | 2.60 ppb |
2015-05-05 | 3761-807-0850 | ND |
2015-07-30 | 9588-002-1044 | ND |
2015-07-30 | 9588-003-1015 | ND |
2015-07-30 | 9588-012-0928 | ND |
2015-08-11 | 3761-800-0910 | 12.8 ppb |
2015-08-11 | 3761-801-0800 | 17.7 ppb |
2015-08-11 | 3761-802-0855 | 13.9 ppb |
2015-08-11 | 3761-803-0826 | 2.40 ppb |
2015-08-11 | 3761-804-0950 | 9.90 ppb |
2015-08-11 | 3761-805-0935 | 3.00 ppb |
2015-08-11 | 3761-806-0926 | 2.70 ppb |
2015-08-11 | 3761-807-0840 | ND |
2015-10-28 | 9588-002-1000 | ND |
2015-10-28 | 9588-003-0945 | ND |
2015-10-28 | 9588-012-0915 | ND |
2015-11-03 | 3761-800-1030 | 5.50 ppb |
2015-11-03 | 3761-801-0815 | 14.1 ppb |
2015-11-03 | 3761-802-1018 | 5.00 ppb |
2015-11-03 | 3761-803-0850 | 2.10 ppb |
2015-11-03 | 3761-804-1000 | 8.70 ppb |
2015-11-03 | 3761-805-0940 | 1.20 ppb |
2015-11-03 | 3761-806-0920 | 2.90 ppb |
2015-11-03 | 3761-807-0830 | ND |
2016-02-02 | 3761-800-0845 | 7.20 ppb |
2016-02-02 | 3761-801-0755 | 7.80 ppb |
2016-02-02 | 3761-802-0830 | 7.00 ppb |
2016-02-02 | 3761-803-0810 | 1.40 ppb |
2016-02-02 | 3761-804-0940 | 7.30 ppb |
2016-02-02 | 3761-805-0920 | 2.20 ppb |
2016-02-02 | 3761-806-0900 | 2.10 ppb |
2016-02-02 | 3761-807-1000 | ND |
2016-03-24 | 9588-002-1024 | ND |
2016-03-24 | 9588-003-1010 | ND |
2016-03-24 | 9588-012-0940 | ND |
2016-05-03 | 3761-800-1100 | 8.30 ppb |
2016-05-03 | 3761-801-0921 | 11.5 ppb |
2016-05-03 | 3761-802-1045 | 9.00 ppb |
2016-05-03 | 3761-803-1010 | 2.40 ppb |
2016-05-03 | 3761-804-1248 | 13.1 ppb |
2016-05-03 | 3761-805-1230 | 2.60 ppb |
2016-05-03 | 3761-806-1121 | 3.40 ppb |
2016-05-03 | 3761-807-1027 | ND |
2016-06-09 | 9588-002-0945 | ND |
2016-06-09 | 9588-003-0923 | ND |
2016-06-09 | 9588-012-0909 | ND |
2016-07-20 | 9588-002-1015 | ND |
2016-07-20 | 9588-003-0945 | ND |
2016-07-20 | 9588-012-0915 | ND |
2016-08-02 | 3761-800-0835 | 13.7 ppb |
2016-08-02 | 3761-801-0820 | 13.4 ppb |
2016-08-02 | 3761-802-0850 | 18.0 ppb |
2016-08-02 | 3761-803-0750 | 2.40 ppb |
2016-08-02 | 3761-804-1005 | 9.80 ppb |
2016-08-02 | 3761-805-0945 | 2.40 ppb |
2016-08-02 | 3761-806-0920 | 4.60 ppb |
2016-08-02 | 3761-807-0805 | 1.20 ppb |
2016-10-12 | 9588-002-0957 | ND |
2016-10-12 | 9588-003-0928 | ND |
2016-10-12 | 9588-012-0914 | ND |
2016-11-01 | 3761-800-0900 | 9.80 ppb |
2016-11-01 | 3761-801-0805 | 11.6 ppb |
2016-11-01 | 3761-802-0915 | 11.1 ppb |
2016-11-01 | 3761-803-0830 | ND |
2016-11-01 | 3761-804-1030 | 9.90 ppb |
2016-11-01 | 3761-805-1000 | 7.10 ppb |
2016-11-01 | 3761-806-0935 | 6.60 ppb |
2016-11-01 | 3761-807-0845 | ND |
2017-01-18 | 9588-002-0935 | ND |
2017-01-18 | 9588-003-0920 | ND |
2017-01-18 | 9588-012-0900 | ND |
2017-02-14 | 3761-800-0900 | 12.2 ppb |
2017-02-14 | 3761-801-0805 | 18.3 ppb |
2017-02-14 | 3761-802-0920 | 12.1 ppb |
2017-02-14 | 3761-803-0845 | 1.60 ppb |
2017-02-14 | 3761-804-1025 | 11.0 ppb |
2017-02-14 | 3761-805-1005 | 4.20 ppb |
2017-02-14 | 3761-806-0940 | 3.60 ppb |
2017-02-14 | 3761-807-0825 | 1.000 ppb |
2017-04-17 | 9588-002-0930 | ND |
2017-04-17 | 9588-003-0952 | ND |
2017-04-17 | 9588-012-0910 | ND |
2017-05-09 | 3761-800-0910 | 10.3 ppb |
2017-05-09 | 3761-801-0740 | 15.4 ppb |
2017-05-09 | 3761-802-1140 | 10.6 ppb |
2017-05-09 | 3761-803-0810 | 2.80 ppb |
2017-05-09 | 3761-804-1118 | 8.40 ppb |
2017-05-09 | 3761-805-1050 | 3.10 ppb |
2017-05-09 | 3761-806-0925 | 4.30 ppb |
2017-05-09 | 3761-807-0845 | ND |
2017-07-24 | 9588-002-1028 | ND |
2017-07-24 | 9588-003-0955 | ND |
2017-07-24 | 9588-012-0923 | ND |
2017-08-08 | 3761-800-0900 | 7.40 ppb |
2017-08-08 | 3761-801-0800 | 8.10 ppb |
2017-08-08 | 3761-802-0920 | 6.40 ppb |
2017-08-08 | 3761-803-0840 | 3.00 ppb |
2017-08-08 | 3761-804-0935 | 7.20 ppb |
2017-08-08 | 3761-805-1000 | 2.40 ppb |
2017-08-08 | 3761-806-1025 | 6.90 ppb |
2017-08-08 | 3761-807-0830 | 1.70 ppb |
2017-10-18 | 9588-002-0950 | ND |
2017-10-18 | 9588-003-0940 | ND |
2017-10-18 | 9588-012-0914 | ND |
2017-11-14 | 3761-800-0825 | ND |
2017-11-14 | 3761-801-0730 | ND |
2017-11-14 | 3761-802-0900 | ND |
2017-11-14 | 3761-803-0810 | 3.80 ppb |
2017-11-14 | 3761-804-1000 | ND |
2017-11-14 | 3761-805-0940 | ND |
2017-11-14 | 3761-806-0920 | ND |
2017-11-14 | 3761-807-0750 | 3.90 ppb |
2018-01-24 | 9588-002-0940 | ND |
2018-01-24 | 9588-003-0920 | ND |
2018-02-06 | 3761-800-0935 | 9.30 ppb |
2018-02-06 | 3761-801-0840 | 11.9 ppb |
2018-02-06 | 3761-802-0950 | 8.30 ppb |
2018-02-06 | 3761-803-0915 | 1.000 ppb |
2018-02-06 | 3761-804-1050 | 8.70 ppb |
2018-02-06 | 3761-805-1030 | 6.00 ppb |
2018-02-06 | 3761-806-1010 | 3.20 ppb |
2018-02-06 | 3761-807-0900 | ND |
2018-04-11 | 9588-002-0953 | ND |
2018-04-11 | 9588-003-0930 | ND |
2018-05-01 | 3761-800-1026 | 7.10 ppb |
2018-05-01 | 3761-801-1005 | 9.40 ppb |
2018-05-01 | 3761-802-1037 | 7.20 ppb |
2018-05-01 | 3761-803-1350 | ND |
2018-05-01 | 3761-804-1300 | 7.70 ppb |
2018-05-01 | 3761-805-1245 | 1.30 ppb |
2018-05-01 | 3761-806-1117 | 2.60 ppb |
2018-05-01 | 3761-807-1410 | ND |
2018-07-25 | 9588-002-1000 | ND |
2018-07-25 | 9588-003-0935 | ND |
2018-08-07 | 3761-800-1023 | 8.90 ppb |
2018-08-07 | 3761-801-0842 | 9.20 ppb |
2018-08-07 | 3761-802-1245 | 9.00 ppb |
2018-08-07 | 3761-803-0936 | ND |
2018-08-07 | 3761-804-1225 | 9.30 ppb |
2018-08-07 | 3761-805-1200 | 1.30 ppb |
2018-08-07 | 3761-806-1048 | 2.90 ppb |
2018-08-07 | 3761-807-1310 | ND |
2018-10-26 | 9588-002-0940 | ND |
2018-10-26 | 9588-003-0920 | ND |
2018-11-06 | 3761-800-0910 | 7.50 ppb |
2018-11-06 | 3761-801-0800 | 9.40 ppb |
2018-11-06 | 3761-802-0855 | 8.10 ppb |
2018-11-06 | 3761-803-0835 | 2.10 ppb |
2018-11-06 | 3761-804-1005 | 7.40 ppb |
2018-11-06 | 3761-805-0947 | 4.50 ppb |
2018-11-06 | 3761-806-0930 | 3.70 ppb |
2018-11-06 | 3761-807-0820 | 1.000 ppb |
2019-01-23 | 9588-002-0950 | ND |
2019-01-23 | 9588-003-0920 | ND |
2019-02-05 | 3761-800-0922 | 8.10 ppb |
2019-02-05 | 3761-801-0830 | 10.5 ppb |
2019-02-05 | 3761-802-0940 | 7.70 ppb |
2019-02-05 | 3761-803-0910 | 2.00 ppb |
2019-02-05 | 3761-804-1036 | 8.20 ppb |
2019-02-05 | 3761-805-1021 | 2.80 ppb |
2019-02-05 | 3761-806-1000 | 3.10 ppb |
2019-02-05 | 3761-807-0856 | 1.000 ppb |
2019-04-25 | 9588-002-1030 | ND |
2019-04-25 | 9588-003-1005 | ND |
2019-05-07 | 3761-800-0835 | 11.8 ppb |
2019-05-07 | 3761-801-0730 | 9.50 ppb |
2019-05-07 | 3761-802-0850 | 5.60 ppb |
2019-05-07 | 3761-803-0755 | 1.70 ppb |
2019-05-07 | 3761-804-0950 | 5.50 ppb |
2019-05-07 | 3761-805-0932 | 4.30 ppb |
2019-05-07 | 3761-806-0915 | 4.60 ppb |
2019-05-07 | 3761-807-0810 | 1.000 ppb |
2019-05-24 | 9588-012-0920 | ND |
2019-07-25 | 9588-002-1035 | ND |
2019-07-25 | 9588-003-1010 | ND |
2019-07-25 | 9588-012-0930 | ND |
2019-08-06 | 3761-800-0850 | 5.90 ppb |
2019-08-06 | 3761-801-0754 | 6.70 ppb |
2019-08-06 | 3761-802-0916 | 5.80 ppb |
2019-08-06 | 3761-803-0833 | 3.00 ppb |
2019-08-06 | 3761-804-1025 | 5.90 ppb |
2019-08-06 | 3761-805-1000 | 3.70 ppb |
2019-08-06 | 3761-806-0940 | 4.60 ppb |
2019-08-06 | 3761-807-0820 | 1.40 ppb |
2019-10-25 | 9588-002-1000 | ND |
2019-10-25 | 9588-003-1040 | ND |
2019-10-25 | 9588-012-0930 | ND |
2019-11-05 | 3761-800-0930 | 7.20 ppb |
2019-11-05 | 3761-801-0830 | 10.3 ppb |
2019-11-05 | 3761-802-0945 | 8.00 ppb |
2019-11-05 | 3761-803-0850 | 2.60 ppb |
2019-11-05 | 3761-804-1055 | 8.10 ppb |
2019-11-05 | 3761-805-1030 | 7.20 ppb |
2019-11-05 | 3761-806-1005 | 7.20 ppb |
2019-11-05 | 3761-807-0910 | 1.20 ppb |