Dibromochloromethane
City of Napa
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.
257
Samples
0
Samples exceeding legal limit (MCL)
252
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | 3.62 ppb | 39 | 37 | ND - 7.50 ppb |
| 2015 | 8.14 ppb | 44 | 44 | 0.610 ppb - 15.0 ppb |
| 2016 | 3.55 ppb | 37 | 36 | ND - 9.30 ppb |
| 2017 | 4.02 ppb | 44 | 42 | ND - 17.0 ppb |
| 2018 | 2.75 ppb | 45 | 45 | 0.740 ppb - 7.50 ppb |
| 2019 | 3.47 ppb | 48 | 48 | 0.820 ppb - 8.10 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 |
|---|---|---|
| 2014-01-08 | 1233-007-0935 | 0.650 ppb |
| 2014-01-08 | 1233-008-1030 | 2.20 ppb |
| 2014-01-08 | 1233-009-1000 | 0.910 ppb |
| 2014-01-08 | 1233-010-1050 | 1.80 ppb |
| 2014-01-08 | 1233-011-1245 | 2.20 ppb |
| 2014-01-08 | 1233-012-1305 | ND |
| 2014-01-08 | 1233-024-1230 | 0.950 ppb |
| 2014-01-08 | 1233-025-1110 | 0.960 ppb |
| 2014-01-08 | 1233-028-1315 | 0.930 ppb |
| 2014-04-02 | 1233-006-1245 | 1.50 ppb |
| 2014-04-02 | 1233-008-1055 | 6.80 ppb |
| 2014-04-02 | 1233-009-1040 | 2.20 ppb |
| 2014-04-02 | 1233-010-1110 | 3.40 ppb |
| 2014-04-02 | 1233-011-1330 | 1.90 ppb |
| 2014-04-02 | 1233-012-1355 | 3.10 ppb |
| 2014-04-02 | 1233-024-1315 | 1.90 ppb |
| 2014-04-02 | 1233-025-1130 | 4.60 ppb |
| 2014-04-02 | 1233-028-1345 | 3.40 ppb |
| 2014-07-09 | 1233-005-1145 | ND |
| 2014-07-09 | 1233-006-1245 | 2.70 ppb |
| 2014-07-09 | 1233-007-0925 | 4.30 ppb |
| 2014-07-09 | 1233-008-1030 | 5.60 ppb |
| 2014-07-09 | 1233-009-1015 | 5.70 ppb |
| 2014-07-09 | 1233-010-1040 | 5.30 ppb |
| 2014-07-09 | 1233-011-1410 | 6.30 ppb |
| 2014-07-09 | 1233-012-1440 | 5.70 ppb |
| 2014-07-09 | 1233-024-1355 | 3.20 ppb |
| 2014-07-09 | 1233-025-1105 | 0.690 ppb |
| 2014-07-09 | 1233-028-1430 | 7.50 ppb |
| 2014-10-01 | 1233-006-1220 | 3.50 ppb |
| 2014-10-01 | 1233-007-1010 | 4.50 ppb |
| 2014-10-01 | 1233-008-1050 | 6.20 ppb |
| 2014-10-01 | 1233-009-1035 | 6.00 ppb |
| 2014-10-01 | 1233-010-1105 | 5.70 ppb |
| 2014-10-01 | 1233-011-1320 | 6.50 ppb |
| 2014-10-01 | 1233-012-1355 | 6.60 ppb |
| 2014-10-01 | 1233-024-1300 | 3.80 ppb |
| 2014-10-01 | 1233-025-1125 | 6.80 ppb |
| 2014-10-01 | 1233-028-1335 | 5.10 ppb |
| 2015-01-08 | 1233-007-1000 | 7.10 ppb |
| 2015-01-08 | 1233-008-1105 | 4.50 ppb |
| 2015-01-08 | 1233-009-1050 | 5.80 ppb |
| 2015-01-08 | 1233-010-1115 | 6.20 ppb |
| 2015-01-08 | 1233-011-1215 | 5.60 ppb |
| 2015-01-08 | 1233-012-1330 | 7.30 ppb |
| 2015-01-08 | 1233-024-1155 | 4.60 ppb |
| 2015-01-08 | 1233-025-1130 | 3.80 ppb |
| 2015-01-08 | 1233-031-1320 | 6.70 ppb |
| 2015-04-01 | 1233-007-0950 | 10.00 ppb |
| 2015-04-01 | 1233-008-1045 | 12.0 ppb |
| 2015-04-01 | 1233-009-1030 | 12.0 ppb |
| 2015-04-01 | 1233-010-1055 | 10.00 ppb |
| 2015-04-01 | 1233-011-1330 | 13.0 ppb |
| 2015-04-01 | 1233-012-1355 | 13.0 ppb |
| 2015-04-01 | 1233-024-1315 | 13.0 ppb |
| 2015-04-01 | 1233-025-1115 | 13.0 ppb |
| 2015-04-01 | 1233-028-1340 | 11.0 ppb |
| 2015-07-21 | 1233-005-1120 | 0.760 ppb |
| 2015-07-21 | 1233-006-1415 | 3.60 ppb |
| 2015-07-21 | 1233-007-0940 | 8.30 ppb |
| 2015-07-21 | 1233-008-1035 | 11.0 ppb |
| 2015-07-21 | 1233-009-1020 | 9.80 ppb |
| 2015-07-21 | 1233-010-1045 | 12.0 ppb |
| 2015-07-21 | 1233-011-1505 | 11.0 ppb |
| 2015-07-21 | 1233-012-1530 | 10.00 ppb |
| 2015-07-21 | 1233-024-1450 | 8.90 ppb |
| 2015-07-21 | 1233-025-1200 | 1.70 ppb |
| 2015-07-21 | 1233-028-1520 | 2.80 ppb |
| 2015-10-07 | 1233-005-1155 | 0.610 ppb |
| 2015-10-07 | 1233-006-1325 | 1.40 ppb |
| 2015-10-07 | 1233-007-1110 | 9.20 ppb |
| 2015-10-07 | 1233-008-1510 | 14.0 ppb |
| 2015-10-07 | 1233-009-1525 | 14.0 ppb |
| 2015-10-07 | 1233-010-1455 | 12.0 ppb |
| 2015-10-07 | 1233-011-1415 | 15.0 ppb |
| 2015-10-07 | 1233-012-1440 | 14.0 ppb |
| 2015-10-07 | 1233-024-1400 | 14.0 ppb |
| 2015-10-07 | 1233-025-1210 | 2.00 ppb |
| 2015-10-07 | 1233-028-1430 | 12.0 ppb |
| 2015-11-04 | 1233-006-1220 | 3.10 ppb |
| 2015-11-04 | 1233-007-1030 | 4.00 ppb |
| 2015-12-02 | 1233-006-1145 | 2.10 ppb |
| 2015-12-02 | 1233-007-1030 | 2.50 ppb |
| 2016-01-08 | 1233-008-1245 | 9.30 ppb |
| 2016-01-08 | 1233-009-1230 | 8.40 ppb |
| 2016-01-08 | 1233-010-1300 | 6.00 ppb |
| 2016-01-08 | 1233-011-1355 | 8.20 ppb |
| 2016-01-08 | 1233-012-1430 | 8.40 ppb |
| 2016-01-08 | 1233-024-1340 | 9.20 ppb |
| 2016-01-08 | 1233-025-1320 | 8.60 ppb |
| 2016-01-08 | 1233-028-1415 | 7.30 ppb |
| 2016-04-06 | 1233-006-1230 | 1.20 ppb |
| 2016-04-06 | 1233-008-1100 | 2.40 ppb |
| 2016-04-06 | 1233-009-1045 | 1.90 ppb |
| 2016-04-06 | 1233-010-1115 | 2.10 ppb |
| 2016-04-06 | 1233-011-1345 | 1.60 ppb |
| 2016-04-06 | 1233-024-1330 | 1.50 ppb |
| 2016-04-06 | 1233-025-1130 | 2.20 ppb |
| 2016-04-06 | 1233-028-1400 | 1.40 ppb |
| 2016-05-04 | 1233-007-1025 | 8.70 ppb |
| 2016-07-27 | 1233-006-1545 | 1.50 ppb |
| 2016-07-27 | 1233-007-1245 | 2.00 ppb |
| 2016-07-27 | 1233-008-1320 | 2.40 ppb |
| 2016-07-27 | 1233-009-1305 | 1.90 ppb |
| 2016-07-27 | 1233-010-1335 | 2.30 ppb |
| 2016-07-27 | 1233-011-1655 | 1.80 ppb |
| 2016-07-27 | 1233-012-1725 | 2.90 ppb |
| 2016-07-27 | 1233-024-1645 | 1.50 ppb |
| 2016-07-27 | 1233-025-1350 | 2.30 ppb |
| 2016-07-27 | 1233-028-1710 | 1.80 ppb |
| 2016-10-05 | 1233-006-1110 | 1.80 ppb |
| 2016-10-05 | 1233-007-0900 | 2.50 ppb |
| 2016-10-05 | 1233-008-1000 | 3.30 ppb |
| 2016-10-05 | 1233-009-0945 | 2.60 ppb |
| 2016-10-05 | 1233-010-1015 | 2.50 ppb |
| 2016-10-05 | 1233-011-1210 | 2.20 ppb |
| 2016-10-05 | 1233-012-1230 | 3.10 ppb |
| 2016-10-05 | 1233-024-1155 | 2.20 ppb |
| 2016-10-05 | 1233-025-1030 | 2.50 ppb |
| 2016-10-05 | 1233-028-1225 | ND |
| 2017-01-11 | 1233-007-1040 | 8.10 ppb |
| 2017-01-11 | 1233-008-1125 | 13.0 ppb |
| 2017-01-11 | 1233-009-1115 | 15.0 ppb |
| 2017-01-11 | 1233-010-1135 | 15.0 ppb |
| 2017-01-11 | 1233-011-1430 | 15.0 ppb |
| 2017-01-11 | 1233-012-1500 | 17.0 ppb |
| 2017-01-11 | 1233-024-1415 | 14.0 ppb |
| 2017-01-11 | 1233-025-1155 | 15.0 ppb |
| 2017-01-11 | 1233-028-1445 | 14.0 ppb |
| 2017-02-01 | 1233-007-1050 | 1.50 ppb |
| 2017-04-05 | 1233-006-1040 | 1.50 ppb |
| 2017-04-05 | 1233-008-0912 | 1.70 ppb |
| 2017-04-05 | 1233-009-0900 | 1.60 ppb |
| 2017-04-05 | 1233-010-0928 | 1.60 ppb |
| 2017-04-05 | 1233-011-1153 | 1.30 ppb |
| 2017-04-05 | 1233-012-1214 | 1.60 ppb |
| 2017-04-05 | 1233-024-1137 | ND |
| 2017-04-05 | 1233-025-0950 | 1.40 ppb |
| 2017-04-05 | 1233-028-1223 | 1.50 ppb |
| 2017-07-20 | 1233-006-1330 | 1.40 ppb |
| 2017-07-20 | 1233-007-1050 | 4.10 ppb |
| 2017-07-20 | 1233-008-1141 | 1.70 ppb |
| 2017-07-20 | 1233-009-1127 | 1.80 ppb |
| 2017-07-20 | 1233-010-1155 | 3.90 ppb |
| 2017-07-20 | 1233-011-1455 | 1.60 ppb |
| 2017-07-20 | 1233-012-1515 | 1.50 ppb |
| 2017-07-20 | 1233-024-1436 | 1.50 ppb |
| 2017-07-20 | 1233-025-1216 | 1.70 ppb |
| 2017-07-20 | 1233-028-1536 | 1.60 ppb |
| 2017-09-06 | 1233-006-0955 | 1.60 ppb |
| 2017-09-06 | 1233-007-0845 | 1.30 ppb |
| 2017-09-13 | 1233-005-0840 | 0.820 ppb |
| 2017-10-04 | 1233-005-1154 | ND |
| 2017-10-04 | 1233-007-0903 | 1.10 ppb |
| 2017-10-04 | 1233-008-0959 | 1.10 ppb |
| 2017-10-04 | 1233-009-0943 | 1.30 ppb |
| 2017-10-04 | 1233-010-1014 | 0.940 ppb |
| 2017-10-04 | 1233-011-1059 | 1.20 ppb |
| 2017-10-04 | 1233-012-1034 | 1.000 ppb |
| 2017-10-04 | 1233-024-1116 | 0.760 ppb |
| 2017-10-04 | 1233-025-1138 | 0.520 ppb |
| 2017-10-04 | 1233-028-1046 | 1.70 ppb |
| 2017-11-01 | 1233-006-1130 | 1.80 ppb |
| 2017-12-06 | 1233-007-1150 | 0.970 ppb |
| 2018-01-10 | 1233-007-1230 | 1.70 ppb |
| 2018-01-10 | 1233-008-1310 | 2.00 ppb |
| 2018-01-10 | 1233-009-1255 | 1.90 ppb |
| 2018-01-10 | 1233-010-1325 | 1.70 ppb |
| 2018-01-10 | 1233-011-1525 | 1.80 ppb |
| 2018-01-10 | 1233-012-1545 | 1.80 ppb |
| 2018-01-10 | 1233-024-1515 | 1.80 ppb |
| 2018-01-10 | 1233-025-1340 | 1.90 ppb |
| 2018-01-10 | 1233-028-1535 | 2.20 ppb |
| 2018-04-11 | 1233-006-1430 | 0.740 ppb |
| 2018-04-11 | 1233-008-1105 | 4.90 ppb |
| 2018-04-11 | 1233-009-1045 | 3.00 ppb |
| 2018-04-11 | 1233-010-1125 | 3.30 ppb |
| 2018-04-11 | 1233-011-1230 | 2.00 ppb |
| 2018-04-11 | 1233-012-1200 | 3.30 ppb |
| 2018-04-11 | 1233-024-1245 | 1.90 ppb |
| 2018-04-11 | 1233-025-1140 | 2.40 ppb |
| 2018-04-11 | 1233-028-1215 | 5.30 ppb |
| 2018-06-06 | 1233-006-1240 | 2.60 ppb |
| 2018-06-06 | 1233-007-1040 | 7.50 ppb |
| 2018-07-11 | 1233-006-1015 | 2.20 ppb |
| 2018-07-11 | 1233-007-1200 | 2.00 ppb |
| 2018-08-08 | 1233-006-1310 | 2.80 ppb |
| 2018-08-08 | 1233-007-1000 | 1.90 ppb |
| 2018-09-05 | 1233-006-1045 | 2.60 ppb |
| 2018-09-05 | 1233-007-1230 | 1.90 ppb |
| 2018-09-18 | 1233-008-1015 | 3.60 ppb |
| 2018-09-18 | 1233-009-1000 | 3.40 ppb |
| 2018-09-18 | 1233-010-1040 | 3.00 ppb |
| 2018-09-18 | 1233-011-1225 | 3.10 ppb |
| 2018-09-18 | 1233-012-1300 | 2.70 ppb |
| 2018-09-18 | 1233-024-1205 | 3.10 ppb |
| 2018-09-18 | 1233-025-1100 | 3.10 ppb |
| 2018-09-18 | 1233-028-1245 | 3.00 ppb |
| 2018-10-03 | 1233-008-1040 | 3.00 ppb |
| 2018-10-03 | 1233-009-1025 | 3.00 ppb |
| 2018-10-03 | 1233-010-1055 | 2.50 ppb |
| 2018-10-03 | 1233-011-1240 | 2.60 ppb |
| 2018-10-03 | 1233-012-1320 | 2.50 ppb |
| 2018-10-03 | 1233-024-1220 | 2.40 ppb |
| 2018-10-03 | 1233-025-1110 | 2.70 ppb |
| 2018-10-03 | 1233-028-1305 | 2.90 ppb |
| 2018-11-07 | 1233-006-1225 | 2.90 ppb |
| 2018-11-07 | 1233-007-1020 | 1.70 ppb |
| 2018-12-05 | 1233-007-1030 | 5.30 ppb |
| 2019-01-09 | 1233-007-0940 | 4.20 ppb |
| 2019-01-09 | 1233-008-1000 | 5.10 ppb |
| 2019-01-09 | 1233-009-0945 | 6.40 ppb |
| 2019-01-09 | 1233-010-1010 | 4.20 ppb |
| 2019-01-09 | 1233-011-1125 | 6.70 ppb |
| 2019-01-09 | 1233-012-1150 | 7.80 ppb |
| 2019-01-09 | 1233-024-1105 | 6.80 ppb |
| 2019-01-09 | 1233-025-1030 | 7.60 ppb |
| 2019-01-09 | 1233-028-1135 | 8.10 ppb |
| 2019-03-06 | 1233-006-1020 | 0.820 ppb |
| 2019-04-03 | 1233-005-1045 | 1.60 ppb |
| 2019-04-03 | 1233-006-1115 | 1.10 ppb |
| 2019-04-03 | 1233-009-1015 | 1.60 ppb |
| 2019-04-03 | 1233-011-1145 | 1.50 ppb |
| 2019-04-03 | 1233-012-1215 | 1.70 ppb |
| 2019-04-03 | 1233-024-1130 | 1.60 ppb |
| 2019-04-03 | 1233-025-1055 | 1.60 ppb |
| 2019-04-03 | 1233-028-1200 | 1.40 ppb |
| 2019-05-01 | 1233-006-1040 | 0.950 ppb |
| 2019-06-12 | 1233-006-1220 | 1.40 ppb |
| 2019-06-12 | 1233-007-1000 | 6.10 ppb |
| 2019-07-10 | 1233-006-1200 | 1.40 ppb |
| 2019-07-10 | 1233-007-0830 | 3.20 ppb |
| 2019-07-10 | 1233-008-0915 | 7.20 ppb |
| 2019-07-10 | 1233-009-0900 | 2.90 ppb |
| 2019-07-10 | 1233-010-0930 | 4.00 ppb |
| 2019-07-10 | 1233-011-1245 | 3.60 ppb |
| 2019-07-10 | 1233-012-1315 | 3.70 ppb |
| 2019-07-10 | 1233-024-1230 | 1.70 ppb |
| 2019-07-10 | 1233-025-0950 | 4.10 ppb |
| 2019-07-10 | 1233-028-1300 | 4.60 ppb |
| 2019-08-07 | 1233-006-1120 | 1.90 ppb |
| 2019-08-07 | 1233-007-1010 | 2.70 ppb |
| 2019-09-04 | 1233-006-1050 | 2.40 ppb |
| 2019-09-04 | 1233-007-0915 | 2.50 ppb |
| 2019-10-02 | 1233-006-1100 | 2.70 ppb |
| 2019-10-02 | 1233-007-0840 | 3.50 ppb |
| 2019-10-02 | 1233-008-0935 | 4.30 ppb |
| 2019-10-02 | 1233-009-0910 | 4.00 ppb |
| 2019-10-02 | 1233-010-0950 | 3.90 ppb |
| 2019-10-02 | 1233-011-1200 | 4.20 ppb |
| 2019-10-02 | 1233-012-1230 | 4.00 ppb |
| 2019-10-02 | 1233-024-1140 | 3.30 ppb |
| 2019-10-02 | 1233-025-1005 | 3.60 ppb |
| 2019-10-02 | 1233-028-1215 | 4.90 ppb |
| 2019-11-06 | 1233-006-1045 | 1.50 ppb |
| 2019-11-06 | 1233-007-0915 | 0.880 ppb |
| 2019-12-04 | 1233-007-1150 | 1.60 ppb |