Dibromochloromethane
Helena Water System
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 | 1.53 ppb | 18 | 17 | ND - 3.10 ppb |
2015 | 0.783 ppb | 19 | 9 | ND - 2.90 ppb |
2016 | 0.725 ppb | 18 | 7 | ND - 3.60 ppb |
2017 | 1.08 ppb | 18 | 9 | ND - 2.70 ppb |
2018 | 0.248 ppb | 19 | 4 | ND - 1.60 ppb |
2019 | 0.688 ppb | 18 | 8 | ND - 2.40 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 |
---|---|---|
2014-02-18 | H14020182-001A | 0.870 ppb |
2014-02-18 | H14020182-002A | 0.840 ppb |
2014-02-18 | H14020182-003A | 0.830 ppb |
2014-02-18 | H14020182-004A | 0.930 ppb |
2014-05-06 | H14050080-001B | 1.30 ppb |
2014-05-06 | H14050080-002B | 1.40 ppb |
2014-05-06 | H14050080-003B | 1.70 ppb |
2014-05-06 | H14050080-004B | 1.50 ppb |
2014-05-27 | H14050436-001A | 0.690 ppb |
2014-05-27 | H14050436-002A | ND |
2014-08-07 | H14080149-001A | 3.10 ppb |
2014-08-07 | H14080149-002A | 2.30 ppb |
2014-08-07 | H14080149-003A | 2.50 ppb |
2014-08-07 | H14080149-004A | 3.00 ppb |
2014-11-11 | H14110156-001A | 1.60 ppb |
2014-11-11 | H14110156-002A | 1.70 ppb |
2014-11-11 | H14110156-003A | 1.40 ppb |
2014-11-11 | H14110156-004A | 1.80 ppb |
2015-02-09 | H15020132-001A | ND |
2015-02-09 | H15020132-002A | ND |
2015-02-09 | H15020132-003A | ND |
2015-02-09 | H15020132-004A | ND |
2015-05-04 | H15050032-001A | 0.630 ppb |
2015-05-04 | H15050032-002A | ND |
2015-05-04 | H15050032-003A | ND |
2015-05-04 | H15050032-004A | ND |
2015-05-21 | H15050321-001A | ND |
2015-05-21 | H15050321-002A | 2.40 ppb |
2015-05-21 | H15050321-003A | ND |
2015-08-04 | H15080039-001A | 1.90 ppb |
2015-08-04 | H15080039-002A | 2.90 ppb |
2015-08-04 | H15080039-003A | 2.70 ppb |
2015-08-04 | H15080039-004A | 2.40 ppb |
2015-11-11 | H15110206-001A | 0.770 ppb |
2015-11-11 | H15110206-002A | 0.580 ppb |
2015-11-11 | H15110206-003A | ND |
2015-11-11 | H15110206-004A | 0.590 ppb |
2016-02-08 | H16020112-001A | ND |
2016-02-08 | H16020112-002A | ND |
2016-02-08 | H16020112-003A | ND |
2016-02-08 | H16020112-004A | ND |
2016-05-04 | H16050062-001A | 0.730 ppb |
2016-05-04 | H16050062-002A | ND |
2016-05-04 | H16050062-003A | ND |
2016-05-04 | H16050062-004A | ND |
2016-05-10 | H16050166-001A | ND |
2016-05-10 | H16050166-002A | 1.000 ppb |
2016-08-11 | H16080311-001A | 3.60 ppb |
2016-08-11 | H16080311-002A | 3.30 ppb |
2016-08-11 | H16080311-003A | 3.10 ppb |
2016-08-11 | H16080311-004A | 0.800 ppb |
2016-11-07 | H16110141-001A | 0.520 ppb |
2016-11-07 | H16110141-002A | ND |
2016-11-07 | H16110141-003A | ND |
2016-11-07 | H16110141-004A | ND |
2017-02-06 | H17020059-001A | ND |
2017-02-06 | H17020059-002A | ND |
2017-02-06 | H17020059-003A | ND |
2017-02-06 | H17020059-004A | ND |
2017-05-10 | H17050211-001A | ND |
2017-05-10 | H17050211-002A | 2.10 ppb |
2017-05-10 | H17050211-003A | ND |
2017-05-10 | H17050211-004A | ND |
2017-05-25 | H17050520-001A | ND |
2017-05-25 | H17050520-002A | 0.820 ppb |
2017-08-16 | H17080330-001A | 2.70 ppb |
2017-08-16 | H17080330-002A | 2.10 ppb |
2017-08-16 | H17080330-003A | 2.60 ppb |
2017-08-16 | H17080330-004A | ND |
2017-11-28 | H17110486-001A | 2.40 ppb |
2017-11-28 | H17110486-002A | 2.20 ppb |
2017-11-28 | H17110486-003A | 2.00 ppb |
2017-11-28 | H17110486-004A | 2.50 ppb |
2018-02-15 | H18020260-001A | ND |
2018-02-15 | H18020260-002A | ND |
2018-02-15 | H18020260-003A | ND |
2018-02-15 | H18020260-004A | ND |
2018-05-09 | H18050233-001A | ND |
2018-05-09 | H18050233-002A | ND |
2018-05-09 | H18050233-003A | ND |
2018-05-09 | H18050233-004A | ND |
2018-05-29 | H18050689-001A | ND |
2018-05-29 | H18050689-002A | 1.000 ppb |
2018-05-30 | H18050718-001A | ND |
2018-08-14 | H18080291-001A | 1.60 ppb |
2018-08-14 | H18080291-002A | 1.60 ppb |
2018-08-14 | H18080291-003A | ND |
2018-08-14 | H18080291-004A | ND |
2018-11-14 | H18110336-001A | 0.520 ppb |
2018-11-14 | H18110336-002A | ND |
2018-11-14 | H18110336-003A | ND |
2018-11-14 | H18110336-004A | ND |
2019-02-06 | H19020065-001A | ND |
2019-02-06 | H19020065-002A | ND |
2019-02-06 | H19020065-003A | ND |
2019-02-06 | H19020065-004A | ND |
2019-05-23 | H19050678-001A | ND |
2019-05-23 | H19050678-002A | 1.20 ppb |
2019-05-23 | H19050678-003A | ND |
2019-05-23 | H19050678-004A | ND |
2019-07-12 | H19070266-001A | ND |
2019-07-12 | H19070266-002A | ND |
2019-08-20 | H19080561-001A | 2.40 ppb |
2019-08-20 | H19080561-002A | 2.40 ppb |
2019-08-20 | H19080561-003A | 2.40 ppb |
2019-08-20 | H19080561-004A | 1.60 ppb |
2019-11-13 | H19110258-001A | 0.920 ppb |
2019-11-13 | H19110258-002A | 0.620 ppb |
2019-11-13 | H19110258-003A | 0.840 ppb |
2019-11-13 | H19110258-004A | ND |