Bromoform
Middleton Waterworks
Bromoform, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Bromoform 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 | 0.119 ppb | 8 | 1 | ND - 0.950 ppb |
| 2015 | 0.300 ppb | 2 | 1 | ND - 0.600 ppb |
| 2016 | 0.490 ppb | 2 | 1 | ND - 0.980 ppb |
| 2017 | 0.0490 ppb | 10 | 1 | ND - 0.490 ppb |
| 2018 | 0.189 ppb | 8 | 3 | ND - 0.950 ppb |
| 2019 | 0.184 ppb | 8 | 3 | ND - 0.670 ppb |
ppb = parts per billion
State and national drinking water standards and health guidelines
EWG Health Guideline 0.5 ppb
The EWG Health Guideline of 0.5 ppb for bromoform 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 |
|---|---|---|
| 2014-04-24 | 782322 | ND |
| 2014-04-24 | 782319 | ND |
| 2014-05-19 | 790001 | ND |
| 2014-05-19 | 790004 | ND |
| 2014-06-03 | 793965 | ND |
| 2014-06-12 | 796624 | ND |
| 2014-08-06 | 808630 | ND |
| 2014-08-06 | 808631 | 0.950 ppb |
| 2015-08-11 | 876294 | ND |
| 2015-08-11 | 876293 | 0.600 ppb |
| 2016-07-12 | 932745 | ND |
| 2016-07-12 | 932744 | 0.980 ppb |
| 2017-05-17 | 990975 | ND |
| 2017-05-17 | 990979 | ND |
| 2017-05-24 | 993618 | ND |
| 2017-06-05 | 995322 | ND |
| 2017-06-19 | 998504 | ND |
| 2017-06-19 | 998507 | ND |
| 2017-07-20 | 1005717 | 0.490 ppb |
| 2017-07-20 | 1005718 | ND |
| 2017-10-11 | 1023851 | ND |
| 2017-10-11 | 1023852 | ND |
| 2018-01-16 | 1037346 | ND |
| 2018-01-16 | 1037347 | ND |
| 2018-04-17 | 1050505 | ND |
| 2018-04-17 | 1050504 | ND |
| 2018-07-16 | 1067427 | 0.950 ppb |
| 2018-07-16 | 1067428 | ND |
| 2018-10-10 | 1086465 | 0.250 ppb |
| 2018-10-10 | 1086464 | 0.310 ppb |
| 2019-01-14 | 1101000 | ND |
| 2019-01-14 | 1100999 | 0.370 ppb |
| 2019-04-16 | 1115418 | ND |
| 2019-04-16 | 1115417 | 0.670 ppb |
| 2019-07-15 | 1134349 | ND |
| 2019-07-15 | 1134350 | ND |
| 2019-10-14 | 1154685 | ND |
| 2019-10-14 | 1154684 | 0.430 ppb |