Dibromochloromethane
Laconia Water Works
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 |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | ND | 1 | 0 | ND |
| 2015 | 0.500 ppb | 1 | 1 | 0.500 ppb |
| 2016 | 0.459 ppb | 17 | 12 | ND - 0.800 ppb |
| 2017 | 0.606 ppb | 17 | 14 | ND - 0.900 ppb |
| 2018 | 0.515 ppb | 17 | 12 | ND - 1.000 ppb |
| 2019 | 0.854 ppb | 17 | 17 | 0.540 ppb - 1.40 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 |
|---|---|---|
| 2014-09-18 | A407848002 | ND |
| 2015-08-07 | A506476002 | 0.500 ppb |
| 2016-01-04 | B600025001 | 0.600 ppb |
| 2016-01-04 | B600025002 | 0.600 ppb |
| 2016-01-04 | B600025003 | ND |
| 2016-01-04 | B600025004 | ND |
| 2016-04-04 | B601610003 | 0.500 ppb |
| 2016-04-04 | B601610004 | 0.500 ppb |
| 2016-04-04 | B601610002 | 0.600 ppb |
| 2016-04-04 | B601610001 | 0.600 ppb |
| 2016-07-05 | B605155001 | 0.800 ppb |
| 2016-07-05 | B605155002 | 0.800 ppb |
| 2016-07-05 | B605155003 | 0.700 ppb |
| 2016-07-05 | B605155004 | 0.700 ppb |
| 2016-08-19 | B607790002 | 0.600 ppb |
| 2016-10-03 | B609269003 | 0.800 ppb |
| 2016-10-03 | B609269004 | ND |
| 2016-10-03 | B609269002 | ND |
| 2016-10-03 | B609269001 | ND |
| 2017-01-04 | B700039001 | 0.700 ppb |
| 2017-01-04 | B700039002 | 0.600 ppb |
| 2017-01-04 | B700039003 | 0.600 ppb |
| 2017-01-04 | B700039004 | ND |
| 2017-04-03 | B701474003 | 0.600 ppb |
| 2017-04-03 | B701474004 | ND |
| 2017-04-03 | B701474002 | 0.700 ppb |
| 2017-04-03 | B701474001 | 0.700 ppb |
| 2017-07-03 | B704714001 | 0.800 ppb |
| 2017-07-03 | B704714002 | 0.900 ppb |
| 2017-07-03 | B704714003 | 0.800 ppb |
| 2017-07-03 | B704714004 | ND |
| 2017-08-11 | B707019002 | 0.600 ppb |
| 2017-10-02 | 174027.04 | 0.900 ppb |
| 2017-10-02 | 174027.03 | 0.700 ppb |
| 2017-10-02 | 174027.01 | 0.900 ppb |
| 2017-10-02 | 174027.02 | 0.800 ppb |
| 2018-01-02 | B800017001 | 0.800 ppb |
| 2018-01-02 | B800017002 | 0.600 ppb |
| 2018-01-02 | B800017003 | 0.600 ppb |
| 2018-01-02 | B800017004 | ND |
| 2018-04-02 | 180077.03 | ND |
| 2018-04-02 | 180077.04 | ND |
| 2018-04-02 | 180077.02 | 0.580 ppb |
| 2018-04-02 | 180077.01 | ND |
| 2018-07-02 | 183711.01 | 0.630 ppb |
| 2018-07-02 | 183711.02 | 0.590 ppb |
| 2018-07-02 | 183711.03 | 0.500 ppb |
| 2018-07-02 | 183711.04 | ND |
| 2018-08-17 | B807141002 | 1.000 ppb |
| 2018-10-01 | 187233.04 | 0.860 ppb |
| 2018-10-01 | 187233.03 | 0.870 ppb |
| 2018-10-01 | 187233.01 | 0.880 ppb |
| 2018-10-01 | 187233.02 | 0.840 ppb |
| 2019-01-02 | 190741.01 | 1.30 ppb |
| 2019-01-02 | 190741.02 | 1.40 ppb |
| 2019-01-02 | 190741.03 | 1.40 ppb |
| 2019-01-02 | 190741.04 | 1.30 ppb |
| 2019-04-02 | 193516.04 | 0.690 ppb |
| 2019-04-02 | 193516.03 | 0.540 ppb |
| 2019-04-02 | 193516.02 | 0.680 ppb |
| 2019-04-02 | 193516.01 | 0.580 ppb |
| 2019-07-01 | 197249.01 | 0.890 ppb |
| 2019-07-01 | 197249.02 | 0.900 ppb |
| 2019-07-01 | 197249.03 | 0.710 ppb |
| 2019-07-01 | 197249.04 | 0.810 ppb |
| 2019-08-19 | B907498002 | 0.600 ppb |
| 2019-10-01 | 201006.01 | 0.620 ppb |
| 2019-10-01 | 201006.02 | 0.750 ppb |
| 2019-10-01 | 201007.01 | 0.620 ppb |
| 2019-10-01 | 201007.02 | 0.730 ppb |