Dibromochloromethane
Clay 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.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2014 | 0.394 ppb | 7 | 6 | ND - 0.610 ppb |
| 2015 | 0.746 ppb | 8 | 8 | 0.500 ppb - 1.29 ppb |
| 2016 | 0.589 ppb | 9 | 9 | 0.320 ppb - 1.30 ppb |
| 2017 | 0.587 ppb | 7 | 7 | 0.330 ppb - 1.20 ppb |
| 2018 | 0.410 ppb | 4 | 4 | 0.270 ppb - 0.480 ppb |
| 2019 | 0.123 ppb | 4 | 1 | ND - 0.490 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 |
|---|---|---|
| 2014-02-11 | S2DBP_1402999-03 | ND |
| 2014-05-20 | S2DBP_1405M33-04 | 0.350 ppb |
| 2014-05-20 | S2DBP_1405M23-01 | 0.350 ppb |
| 2014-09-09 | S2DBP_1409941-05 | 0.550 ppb |
| 2014-09-09 | S2DBP_1409941-04 | 0.610 ppb |
| 2014-11-11 | S2DBP_1411B39-01 | 0.420 ppb |
| 2014-11-11 | S2DBP_1411B37-01 | 0.480 ppb |
| 2015-02-10 | S2DBP_1502A39-02 | 0.500 ppb |
| 2015-02-10 | S2DBP_1502A39-01 | 0.500 ppb |
| 2015-05-12 | S2THM_1505C63-05 | 0.740 ppb |
| 2015-05-12 | S2THM_1505C63-03 | 0.670 ppb |
| 2015-08-11 | S2DBP_1508B35-04 | 1.29 ppb |
| 2015-08-11 | S2DBP_1508B35-03 | 1.14 ppb |
| 2015-11-10 | 1511B43-05A | 0.540 ppb |
| 2015-11-10 | 1511B43-04A | 0.590 ppb |
| 2016-02-09 | 1602B51-05A | 0.430 ppb |
| 2016-02-09 | 1602B51-04A | 0.390 ppb |
| 2016-05-17 | 16051879-05A | 0.460 ppb |
| 2016-05-17 | 16051879-04A | 0.440 ppb |
| 2016-08-09 | 16081118-04A | 1.08 ppb |
| 2016-08-09 | 16081118-03A | 0.390 ppb |
| 2016-09-13 | 16091187-03A | 1.30 ppb |
| 2016-11-15 | 16111773-04A | 0.490 ppb |
| 2016-11-15 | 16111773-03A | 0.320 ppb |
| 2017-02-14 | 17021661-05A | 0.330 ppb |
| 2017-02-14 | 17021661-04A | 0.330 ppb |
| 2017-05-09 | 17051090-05A | 0.400 ppb |
| 2017-05-09 | 17051090-04A | 0.400 ppb |
| 2017-08-08 | 17081071-04A | 1.10 ppb |
| 2017-08-08 | 17081071-03A | 1.20 ppb |
| 2017-11-14 | 17111808-04A | 0.350 ppb |
| 2018-02-13 | 18021541-04A | 0.480 ppb |
| 2018-05-08 | 18051052-04A | 0.270 ppb |
| 2018-08-14 | 18082081-04A | 0.420 ppb |
| 2018-11-13 | 18111589-03A | 0.470 ppb |
| 2019-02-12 | 19021253-05A | ND |
| 2019-05-14 | 19051749-05A | ND |
| 2019-08-06 | 35488590001 | ND |
| 2019-11-12 | 737758003 | 0.490 ppb |